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Cashmere goats possess two types of hair follicles, with the secondary hair follicles producing valuable cashmere fiber used for textiles. The growth of cashmere exhibits a seasonal pattern arising from photoperiod change. Transcription factors play crucial roles during this process. The transcription factor, cold-shock domain, containing C2 (Csdc2) plays a crucial role in modulating cell proliferation and differentiation. Our preceding research indicated that the expression of Csdc2 changes periodically during anagen to telogen. However, the mechanisms of Csdc2 in regulating SHF growth remain unclear. Here, we found that the knockdown of Csdc2 inhibits the proliferation of dermal papilla cells. ChIP-Seq analysis showed that Csdc2 had a unique DNA binding motif in SHFs. Through conjoint analysis of ChIP-Seq and RNA-Seq, we revealed a total of 25 candidate target genes of Csdc2. Notably, we discovered a putative Csdc2 binding site within roundabout guidance receptor 2 (Robo2) on chromosome 1 of the goat genome. Furthermore, qRT-PCR and dual-luciferase reporter assay confirmed Csdc2's positive regulatory influence on Robo2. These findings expand the research field of hair follicle transcriptional regulatory networks, offering insights into molecular breeding strategies to enhance cashmere production in goats. [ABSTRACT FROM AUTHOR]

Simple Summary: Cashmere goats are valuable genetic resources which are famous for their high-quality fiber. Runs of homozygosity (ROHs) refer to uninterrupted sequences of homozygous genotypes present within the DNA sequence of an individual. To enhance the preservation, improvement and enduring utilization of this valuable genetic resource, we performed a comprehensive study on the genetic variance, degree of inbreeding, patterns of ROHs and selected genes situated in ROH islands which are associated with economic attributes in goats via whole-genome sequencing analysis. Our research showed that the Inner Mongolia cashmere goat possesses a notably high level of genetic diversity and presented the lowest inbreeding coefficient. On the contrary, the highest F r o h and lowest levels of diversity were observed in wild goats compared to domesticated goats. The analysis of selection signal through ROHs identified some genes related to meat, fiber and milk production; fertility, disease and cold resistance and adaptability; and body size and growth. Cashmere goats are valuable genetic resources which are famous worldwide for their high-quality fiber. Runs of homozygosity (ROHs) have been identified as an efficient tool to assess inbreeding level and identify related genes under selection. However, there is limited research on ROHs in cashmere goats. Therefore, we investigated the ROH pattern, assessed genomic inbreeding levels and examined the candidate genes associated with the cashmere trait using whole-genome resequencing data from 123 goats. Herein, the Inner Mongolia cashmere goat presented the lowest inbreeding coefficient of 0.0263. In total, we identified 57,224 ROHs. Seventy-four ROH islands containing 50 genes were detected. Certain identified genes were related to meat, fiber and milk production (FGF1, PTPRM, RERE, GRID2, RARA); fertility (BIRC6, ECE2, CDH23, PAK1); disease or cold resistance and adaptability (PDCD1LG2, SVIL, PRDM16, RFX4, SH3BP2); and body size and growth (TMEM63C, SYN3, SDC1, STRBP, SMG6). 135 consensus ROHs were identified, and we found candidate genes (FGF5, DVL3, NRAS, KIT) were associated with fiber length or color. These findings enhance our comprehension of inbreeding levels in cashmere goats and the genetic foundations of traits influenced by selective breeding. This research contributes significantly to the future breeding, reservation and use of cashmere goats and other goat breeds. [ABSTRACT FROM AUTHOR]

Runs of Homozygosity (ROH) are continuous homozygous DNA segments in diploid genomes, which have been used to estimate the genetic diversity, inbreeding levels, and genes associated with specific traits in livestock. In this study, we analyzed the resequencing data from 10 local goat breeds in Yunnan province of China and five additional goat populations obtained from a public database. The ROH analysis revealed 21,029 ROH segments across the 15 populations, with an average length of 1.27 Mb, a pattern of ROH, and the assessment of the inbreeding coefficient indicating genetic diversity and varying levels of inbreeding. iHS (integrated haplotype score) was used to analyze high-frequency Single-Nucleotide Polymorphisms (SNPs) in ROH regions, specific genes related to economic traits such as coat color and weight variation. These candidate genes include OCA2 (OCA2 melanosomal transmembrane protein) and MLPH (melanophilin) associated with coat color, EPHA6 (EPH receptor A6) involved in litter size, CDKAL1 (CDK5 regulatory subunit associated protein 1 like 1) and POMC (proopiomelanocortin) linked to weight variation and some putative genes associated with high-altitude adaptability and immune. This study uncovers genetic diversity and inbreeding levels within local goat breeds in Yunnan province, China. The identification of specific genes associated with economic traits and adaptability provides actionable insights for utilization and conservation efforts. [ABSTRACT FROM AUTHOR]

Simple Summary: We performed a genome-wide association study of 100 sheep genomes to investigate the hereditary basis of the four-horn phenotype (FHP) in sheep. The results revealed that a total of 3 InDels (e.g., CHR2: g.133,742,709delA and g.133,743,215insC) and 14 SNPs (e.g., CHR2: g.133,727,513C > T and CHR16: g.40,351,378G > A) in CHR2 and CHR16 were significantly associated with the four-horn trait. Furthermore, HOXD1 and ADAMTS12 annotated from both CHR sequences were the key candidate gene loci contributing to FHP in sheep. This study provided a novel understanding of the Mendelian genetic basis for four horns in sheep. Horns are an important breeding trait for sheep. However, no widely recognized viewpoint on the regulatory genes and mechanisms of horns is available, and the genetic basis of the four-horn phenotype (FHP) is unclear. This work conducted a genome-wide association study with 100 sheep genomes from multiple breeds to investigate the genetic basis of the FHP. The results revealed three significant associations (corrected as p < 1.64 × 10−8) of the InDels (CHR2: g.133,742,709delA, g.133,743,215insC, and g.133,743,940delT) for FHP in the intergenic sequence (IGS) between the MTX2 and the LOC105609047 of CHR2. Moreover, 14 significant associations (corrected as p < 1.42 × 10−9) of SNPs with the FHP phenotype were identified in CHR2 and CHR16, including five (e.g., CHR16: g.40,351,378G > A and g.40,352,577G > A) located in the intron of the ADAMTS12 gene, eight (e.g., CHR2: g.133,727,513C > T and g.133,732,145T > G) in the IGS between MTX2 and LOC105609047, and only one (CHR2: g.133,930,761A > G) in the IGS between HOXD1 and MTX2. Obvious divergence was also observed in genotype patterns between the FHP and others (two horns and hornless) in the HOXD1 and ADAMTS12 gene regions. An extremely significant linkage also occurred between Loci I and Loci II within 100 individuals (LD = −156.02186, p < 0.00001). In summary, our study indicated that the genomic sequences from CHR2 and CHR16 contributed to the FHP in sheep, specifically the key candidate genes HOXD1 and ADAMTS12. These results improved our understanding of the Mendelian genetic basis of the FHP in sheep. [ABSTRACT FROM AUTHOR]

Simple Summary: In our research, candidate genes related to sheep-milk production were revealed by a genome-resequencing analysis and a genome-signal-selection analysis, and a RT-qPCR experiment was performed to prove the expression levels of these candidate genes, the results showed that the FCGR3A gene's expression level had a significant negative relationship with sheep-milk production. Natural selection and domestication have shaped modern sheep populations into a vast range of phenotypically diverse breeds. Among these breeds, dairy sheep have a smaller population than meat sheep and wool sheep, and less research is performed on them, but the lactation mechanism in dairy sheep is critically important for improving animal-production methods. In this study, whole-genome sequences were generated from 10 sheep breeds, including 57 high-milk-yield sheep and 44 low-milk-yield sheep, to investigate the genetic signatures of milk production in dairy sheep, and 59,864,820 valid SNPs (Single Nucleotide Polymorphisms) were kept after quality control to perform population-genetic-structure analyses, gene-detection analyses, and gene-function-validation analyses. For the population-genetic-structure analyses, we carried out PCA (Principal Component Analysis), as well as neighbor-joining tree and structure analyses to classify different sheep populations. The sheep used in our study were well distributed in ten groups, with the high-milk-yield-group populations close to each other and the low-milk-yield-group populations showing similar classifications. To perform an exact signal-selection analysis, we used three different methods to find SNPs to perform gene-annotation analyses within the 995 common regions derived from the fixation index (FST), nucleotide diversity (Ɵπ), and heterozygosity rate (ZHp) results. In total, we found 553 genes that were located in these regions. These genes mainly participate in the protein-binding pathway and the nucleoplasm-interaction pathway, as revealed by the GO- and KEGG-function-enrichment analyses. After the gene selection and function analyses, we found that FCGR3A, CTSK, CTSS, ARNT, GHR, SLC29A4, ROR1, and TNRC18 were potentially related to sheep-milk-production traits. We chose the strongly selected genes, FCGR3A, CTSK, CTSS, and ARNT during the signal-selection analysis to perform a RT-qPCR (Reale time Quantitative Polymerase Chain Reaction) experiment to validate their expression-level relationship with milk production, and the results showed that FCGR3A has a significant negative relationship with sheep-milk production, while other three genes did not show any positive or negative relations. In this study, it was discovered and proven that the candidate gene FCGR3A potentially contributes to the milk production of dairy sheep and a basis was laid for the further study of the genetic mechanism underlying the strong milk-production traits of sheep. [ABSTRACT FROM AUTHOR]

Simple Summary: A unique structure of ruminants, the horn trait is not only closely related to natural and sexual selection but is also an important trait for polled sheep breeding. RXFP2 may be a crucial gene in regulating sheep horn. However, the underlying genetic mechanisms of sheep horn development remain largely unknown. In this study, we investigated the gene expression profile of the horn buds in sheep fetuses using RNA-seq technology. We identified 68 differentially expressed genes in the horn buds of 105-day-old Altay sheep fetuses, including RXFP2, FOXL2, and TNN. Further, we found that the Wnt signaling pathway may be responsible for horn development. Our study provides new possible marker genes for horn development, which may promote our understanding of the genetic mechanisms of sheep horn formation. Horns, also known as headgear, are a unique structure of ruminants. As ruminants are globally distributed, the study of horn formation is critical not only for increasing our understanding of natural and sexual selection but also for the breeding of polled sheep breeds to facilitate modern sheep farming. Despite this, a significant number of the underlying genetic pathways in sheep horn remain unclear. In this study, to clarify the gene expression profile of horn buds and investigate the key genes in horn bud formation, RNA-sequencing (RNA-seq) technology was utilized to investigate differential gene expression in the horn buds and adjacent forehead skin of Altay sheep fetuses. There were only 68 differentially expressed genes (DEGs) identified, consisting of 58 up-regulated genes and 10 down-regulated genes. RXFP2 was differentially up-regulated in the horn buds and had the highest significance (p-value = 7.42 × 10−14). In addition, 32 DEGs were horn-related genes identified in previous studies, such as RXFP2, FOXL2, SFRP4, SFRP2, KRT1, KRT10, WNT7B, and WNT3. Further, Gene Ontology (GO) analysis showed that the DEGs were mainly enriched with regard to growth, development, and cell differentiation. Pathway analysis revealed that the Wnt signaling pathway may be responsible for horn development. Further, through combining the protein–protein interaction networks of the DEGs, it was found that the top five hub genes, namely, ACAN, SFRP2, SFRP4, WNT3, and WNT7B, were also associated with horn development. Our results suggest that only a few key genes, including RXFP2, are involved in bud formation. This study not only validates the expression of candidate genes identified at the transcriptome level in previous studies but also provides new possible marker genes for horn development, which may promote our understanding of the genetic mechanisms of horn formation. [ABSTRACT FROM AUTHOR]

Simple Summary: Skeletal muscle satellite cells (SMSCs) serve as the source of myogenic cells and can afford to differentiate into myotubes as well as act as a model for exploring myogenesis in vitro. In this study, the transcriptional profile of ovine skeletal muscle satellite cells was constructed via the RNA-Seq method. A total of 1954 DEGs, 1479 AS, and 253 TFs were detected during the proliferation and differentiation of SMSCs. GO and KEGG analyses showed that the MAPK signaling pathway, PI3K-Akt signaling pathway, Wnt signaling pathway, and Ras signaling pathway were enriched. Together, our study provides novel insights into the transcription regulation of SMSCs during proliferation and differentiation at the transcriptional level, and provides a valuable resource for understanding the molecular mechanism of myogenesis and muscle development. Skeletal muscle satellite cells (SMSCs), which are highly multifunctional muscle-derived stem cells, play an essential role in myogenesis and regeneration. Here, the transcriptional profile of SMSCs during proliferation and differentiation were constructed using the RNA-Seq method. A total of 1954 differentially expressed genes (DEGs) and 1092 differentially alternative splicing genes (DAGs) were identified including 1288 upregulated genes as well as 666 downregulated genes. GO and KEGG analyses showed that the DEGs and DAGs were enriched in the MAPK (mitogen-activated protein kinase) signaling pathway, the PI3K-Akt (phosphatidylinositol-tris-phosphate kinase 3/protein kinase B) signaling pathway, the Wnt signaling pathway, and the Ras signaling pathway. In total, 1479 alternative splice events (AS) were also identified during SMSC proliferation and differentiation. Among them, a unique AS event was the major per-mRNA splicing type, and SE was the predominant splicing pattern. Furthermore, transcription factors with AS were scanned during SMSC differentiation such as myocyte enhancer factor-2C (MEF2C) and the nuclear receptor subfamily 4 group A member 2 (NR4A2). Our results imply that MEF2C and NR4A2 can interact, and we speculate that NR4A2 and MEF2C might regulate the myogenesis of ovine SMSCs through interaction. Together, our study provides useful information on the transcriptional regulation of SMSCs during proliferation and differentiation at the transcriptional level, and provides a valuable resource for understanding the molecular mechanism of myogenesis and muscle development. [ABSTRACT FROM AUTHOR]

Tibetan sheep are one of the three major coarse sheep breeds in China, and they possess a long history of formation. However, few studies have been conducted on the identification of Tibetan sheep breeds at the molecular level. In this study, a total of 448 individuals from 24 Tibetan sheep populations in the 5 regions of Tibet, Qinghai, Gansu, Yunnan, and Sichuan were analyzed using the Affymetrix Ovine SNP 600K high-density chip to construct specific single-nucleoside polymorphism (SNP) genetic marker sets of Tibetan sheep breeds. Firstly, the genetic structure analysis showed that Yunnan–Tibetan sheep (NL, Ninglang; JC, Jianchuan), Zuogong (ZG), Heizang (HZ), Gongga (GG,) and Tao sheep (TS) can be clearly distinguished from other Tibetan sheep populations. Next, based on the population differentiation index FST, the PCA and NJ tree results showed that only 60 specific SNPs can successfully separate Tibetan sheep in the Yunnan region from Tibetan sheep in other regions, and the distinguishing effect on Yunnan–Tibetan sheep reached 100%. Using the same method, we found that 4 Tibetan sheep breeds, including Zuogong (ZG, 20 SNPs), Heizang (HZ, 60 SNPs), Gongga (GG, 60 SNPs), and Tao sheep (TS, 30 SNPs), can also be distinguished from other Tibetan sheep populations with only a few SNP loci (20–60), and the distinguishing effect reached 100%. Overall, we successfully obtained a Yunnan region-specific (60 SNPs) genetic marker set and 4 breed-specific SNP genetic marker sets (20–60 SNPs) for the first time for the identification of Tibetan sheep breeds at the molecular level. These made up for the lack of genetic marker sets for the identification of Tibetan sheep breeds, and provided a genomic basis for the scientific classification and accurate identification of livestock and poultry genetic resources on the Qinghai–Tibet Plateau. [ABSTRACT FROM AUTHOR]

Transcription factor zinc-finger BED domain-containing protein 6 (ZBED6) is unique to placental mammals and regulates insulin-like growth factor 2 (IGF2) expression, which lead to muscle growth. However, the effect of ZBED6 on the growth of spleen is still elusive. In this study, we explored the regulation of ZBED6 on spleen growth, and the results showed ZBED6 knockout (ZBED6 KO) pigs had heavier spleens than wild-type (WT) pigs. To analyze the mechanism of increased spleen weight in ZBED6 KO pigs, long noncoding RNAs (lncRNAs) and mRNAs in the spleen samples (WT:ZBED6 KO pigs = 3:3) were analyzed to identify differentially expressed lncRNAs (DE-lncRNAs) and genes (DEGs) based on the RNA sequencing (RNA-seq) method. Then, 142 DEGs and 82 DE-lncRNAs were obtained. The qRT-PCR results were consistent with those of the RNA-seq, indicating that the data were reliable. The heavier spleen weight of ZBED6 KO pigs coincided with the significantly upregulated IGF2 mRNA. Functional enrichment analysis of DEGs showed enrichment mainly in myofibril assembly and sarcomere. In addition, 252 cis- and 109 trans-acting target genes of 82 DE-lncRNAs were predicted. By conjoint analysis of lncRNA and mRNA revealed that IGF2, DE-lnRNAs (XLOC_113021, XLOC_078852, NONSUSG004057.1, NONSUSG014354.1, and NONSUSG009750.1), and their target gene ACTN2 may be the key candidate genes in promoting spleen growth in ZBED6 KO pigs. This study provides new directions to understand the global functions of ZBED6 and lncRNAs in spleen growth in pigs. [ABSTRACT FROM AUTHOR]

Meanwhile, we integrated the gene sets (Table S3) and compared them with the DEGs identified in this study; these sets included the horn-related genes and proteins of sheep, goats, and cattle horns identified in previous studies [1,3,10,12-15,27-34]. Meanwhile, we integrated the gene sets (Table S3) and compared them with the DEGs identified in this study; these sets included the horn-related genes and proteins of sheep, goats, and cattle horns identified in previous studies [1,3,10,12-15,17,29-35]. The shape of sheep horn buds is similar to that of cattle horn buds [20]. [Extracted from the article]

As relatively new members of the non-coding RNA family, circRNAs play important roles in a variety of biological processes. However, the temporal expression pattern and the function of circRNAs during sheep skeletal muscle development remains unclear. This study aimed to identify circRNAs related to sheep skeletal muscle development and explore their roles in myoblast proliferation. The circRNA expression profiles of longissimus dorsi of sheep from F90, L30, and A3Y were obtained by the RNA-seq method. The function and mechanisms of the novel circCHRNG in muscle satellite cell proliferation were explored using CCK-8 assay, Western blot, qPCR, and dual-luciferase reporter assay. We identified 12,375 circRNAs, including 476, 133, and 233 DEcircRNAs found among three comparative groups. KEGG results showed that DEcircRNAs were enriched in muscle contraction, the regulation of cell proliferation, and the AMPK, insulin, and PI3K-Akt signaling pathways. Notably, a novel circRNA, termed circRNA CHRNG, acts as a miR-133 sponge to promote skeletal muscle satellite cell proliferation. Our study provides a systematic description of circRNAs of ovine skeletal muscle across fetal, lamb, and adult stages. GO and KEGG analyses showed that DEcircRNAs were enriched in multiple pathways associated with muscle development, such as the PI3K-Akt and AMPK signaling pathways. In addition, we propose that circCHRNG acts as a miR-133 sponge to upregulate the expression levels of SRF and MEF2A, thereby promoting myoblast proliferation. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the family structure, parent–child pair and inbreeding coefficient of a Tan sheep breeding farm in Ningxia, China. The results can be used as the theoretical basis for selecting excellent breeding stock and making an apposite mating plan; furthermore, it can provide an important scientific basis for the conservation and reproduction of Tan sheep germplasm resources. Tan sheep is a special breed of locally protected sheep in China, one of the best quality meat sheep in the world. Due to the unclear pedigree of the rams on the Ningxia Tan sheep breeding farm, we investigated 74 rams in the field and explored a new method for family division. Genomic DNA was extracted from the blood of breeding rams. Using Plink software, GCTA tools and R language, we analyzed the genetic structure, kinship, and inbreeding coefficient of the breeding sheep, which revealed the genetic relationship between the individuals. The results showed that there was no obvious clustering phenomenon in the PCA, and the genetic background of the samples was similar. The G matrix and IBS distance matrix indicated that most individuals were far away from each other. Paternity testing identified 24 pairs of unknown parent–child pairs, and all the Tan sheep could be divided into 12 families, which provided a reference for sheep breeding. The average inbreeding coefficient based on the ROH of this population was 0.049, so there was a low degree of inbreeding and the rams in the field were able to maintain high genetic diversity. Overall, we explored a more accurate method through paternity and kinship analysis; it provides a scientific basis for pedigree construction, which has an important application value for Tan sheep breeding. [ABSTRACT FROM AUTHOR]

The ZBED6 gene is a transcription factor that regulates the expression of IGF2 and affects muscle growth and development. However, its effect on the growth and development of the heart is still unknown. Emerging evidence suggests that long noncoding RNAs (lncRNAs) can regulate genes at the epigenetic, transcriptional, and posttranscriptional levels and play an important role in the development of eukaryotes. To investigate the function of ZBED6 in the cardiac development of pigs, we constructed the expression profiles of mRNAs and lncRNAs in myocardial tissue obtained from Bama Xiang pigs in the ZBED6 knockout group (ZBED6-KO) and the wild-type group (ZBED6-WT). A total of 248 differentially expressed genes (DEGs) and 209 differentially expressed lncRNAs (DELs) were detected, and 105 potential cis target genes of DELs were identified. The functional annotation analysis based on the Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) databases revealed two GO items related to muscle development by the cis target genes of DELs. Moreover, IGF2 was the direct target gene of ZBED6 by ChIP-PCR experiment. Our results explored the mechanism and expression profile of mRNAs and lncRNAs of ZBED6 gene knockout on myocardium tissue development, mining the key candidate genes in that process like IGF2. [ABSTRACT FROM AUTHOR]

Bactrian camels (Camelus bactrianus) are highly adapted to the desert and semi-desert environments of Asia and developed unique physiological adaptations to cold, heat, drought, and nutrient-poor conditions. These animals are an ideal model for studying desert adaptation. However, the transcriptome of different Bactrian camel tissues has not been profiled. This study performed a comprehensive transcriptome analysis of nine fetal and adult tissues. A total of 20,417 coding genes were identified, and 2.4 billion reads were generated. Gene expression and functional analyses revealed that approximately 50% of the identified genes were ubiquitously expressed, and one-third were tissue-elevated genes, which were enriched in pathways related to the biological functions of the corresponding tissue. Weighted gene co-expressed network analysis (WGCNA) identified four modules—fat metabolism, water balance, immunity, and digestion—and several hub genes, including APOA1, TMEM174, CXCL12, and MYL9. The analysis of differentially expressed genes (DEGs) between fetal and adult tissues revealed that downregulated genes were enriched in tissue development, whereas upregulated genes were enriched in biological function in adult camels. DEGs in the hump were enriched in immune-related pathways, suggesting that this tissue is involved in immunity. This study is the first to generate a transcriptome atlas of major tissues in Bactrian camels and explores the genes potentially involved in the adaptation to desert environments. [ABSTRACT FROM AUTHOR]

Simple Summary: Boer goat is a world-famous meat-type goat breed that underwent long-term artificial selection from African indigenous animals. The current study displayed the genome-wide selection signature analyses of South African indigenous goat (AF), African Boer (BH), and Australian Boer (AS), to investigate the hereditary basis of artificial selection in different stages. Moreover, the θπ, FST, and XP-CLR methods were used to search for the candidate signatures of positive selection in Boer goats. Ten genes (e.g., BMPR1B, DNER, ITGAL, and KIT) under selection in both groups were identified and are potentially responsible for reproduction, metabolism, growth, and development. This study provided a comprehensive overview of genomic variations in Boer goat, which may provide a basis for further resource protection and improvement of this breed. Boer goats, as kemp in meat-type goats, are selected and bred from African indigenous goats under a long period of artificial selection. Their advantages in multiple economic traits, particularly their plump growth, have attracted worldwide attention. The current study displayed the genome-wide selection signature analyses of South African indigenous goat (AF), African Boer (BH), and Australian Boer (AS) to investigate the hereditary basis of artificial selection in different stages. Four methods (principal component analysis, nucleotide diversity, linkage disequilibrium decay, and neighbor-joining tree) implied the genomic diversity changes with different artificial selection intensities in Boer goats. In addition, the θπ, FST, and XP-CLR methods were used to search for the candidate signatures of positive selection in Boer goats. Consequently, 339 (BH vs. AF) and 295 (AS vs. BH) candidate genes were obtained from SNP data. Especially, 10 genes (e.g., BMPR1B, DNER, ITGAL, and KIT) under selection in both groups were identified. Functional annotation analysis revealed that these genes are potentially responsible for reproduction, metabolism, growth, and development. This study used genome-wide sequencing data to identify inheritance by artificial selection. The results of the current study are valuable for future molecular-assisted breeding and genetic improvement of goats. [ABSTRACT FROM AUTHOR]

The dairy sheep industry is an important but lacking part of the small ruminant industry. For a sheep breeding program, in addition to wool and meat use, sheep milk can also be processed into high-end dairy products such as cheese and milk powder and bring high economic interests for businesses home and abroad. With increasing interest in sheep milk, the content of which is becoming increasingly clearer, people have found that the nutritional value of sheep milk is higher than that of goat milk and cow milk, with abundant fat yield, protein percentage, and mineral contents, which provide a good opportunity for the development of the sheep milk industry. This review will introduce some dairy sheep breeds with the highest milk production worldwide and compare sheep milk nutrition contents with other ruminants' milk. Moreover, genes influencing lactation or mammary gland growth like CSN2, SLC2A2, SCD, and SOCS2, which have been revealed in recent studies to significantly affect milk production and milk composition traits will be discussed. For the SLC2A2 gene, working as an important solute carrier to transport small molecular nutrition from blood to milk and SOCS2 gene mutation as an indicator of mastitis, in addition, other genes have been detected that correlate with milk traits, which will be introduced in the review. Some personal opinions into future sheep milk development will be given in the final part of the text. Although the research of sheep milk genetic factors has achieved some progress in recent years, there is still a long way to go. [ABSTRACT FROM AUTHOR]

The hair follicle is a complex mini-organ in the skin that undergoes organ induction, morphogenesis, and regeneration. However, the accurate molecular mechanism of skin and hair diversity regulation is still elusive. The sheep is an animal model that can be used to further explore the mechanisms of skin and hair diversity. In this study, we carried out a transcriptomic analysis of the mRNA expression in the skin of Xinji fine-wool sheep at different growth stages (3 and 12 months old) and 12-month-old Tan sheep and explored the transcripts' relationship with hair follicle growth. A total of 1327 mRNAs and 67 transcription factors were identified to be differentially expressed in the different breeds and during different periods of skin development. The differentially expressed genes were enriched in GO terms represented by system development, multicellular organism development, animal organ development, and skin development, and three KEGG pathways typified those governing differences in skin structure. Combining protein–protein interaction networks of skin development (GO:0043588) and functional annotation, nine important candidate genes, namely, LAMA5, OVOL1, SRF, DHCR24, NGFR, SMO, CDSN, HOXC13, and KDF1, and many core genes with minor effects were confirmed to be associated with hair follicle development. Furthermore, members of the zf-C2H2 and homeobox transcription factor families, which were identified to play a crucial role in producing finer and denser wool, were mainly upregulated in 12-month-old Xinji fine-wool sheep when compared with expression in 12-month-old Tan sheep and 3-month-old Xinji fine-wool sheep. This study revealed the major–minor gene interactions in the developmental pathway and provided ideas for an in-depth understanding of the genetic structure and gene regulation in the skin/hair growth process. [ABSTRACT FROM AUTHOR]

Simple Summary: The high-quality lambskin of the Chinese Zhongwei goat has a high economic value. The quality of lamb skin is mainly affected by the curvature of the wool, which is regulated by the growth and development of hair follicles. In this study, the expression profiles of long non-coding RNAs (lncRNAs) of 45-day-old and 108-day-old Zhongwei goats were constructed by the Ribo Zero RNA sequencing. A total of 60 differential lncRNAs and 352 differential mRNAs were identified. The functional annotation of differential lncRNAs target genes showed that they were mainly enriched in PI3K-Akt and Arachidonic acid metabolic signaling pathways. In combination with qRT-PCR and WGCNA results, we speculate that LOC102172600 and LOC102191729 might affect hair follicle development and wool curvature by regulating the target genes. These results provide new insights into the potential role of lncRNA in regulating wool bending. Chinese Zhongwei goat is a rare and precious fur breed as its lamb fur is a well-known fur product. Wool bending of lamb fur of the Zhongwei goat is its most striking feature. However, the curvature of the wool decreases gradually with growth, which significantly affects its quality and economic value. The mechanism regulating the phenotypic changes of hair bending is still unclear. In the present study, the skin tissues of Zhongwei goats at 45 days (curving wool) and 108 days (slight-curving wool) after birth were taken as the research objects, and the expression profiling of long non-coding RNAs (lncRNAs) and mRNAs were analyzed based on the Ribo Zero RNA sequencing (RNA-seq) method. In total, 46,013 mRNAs and 13,549 lncRNAs were identified, of which 352 were differentially expressed mRNAs and 60 were. lncRNAs. Functional enrichment analysis of the target genes of lncRNAs were mainly enriched in PI3K-Akt, Arachidonic acid metabolic, cAMP, Wnt, and other signaling pathways. The qRT-PCR results of eight selected lncRNAs and target genes were consistent with the sequencing result, which indicated our data were reliable. Through the analysis of the weighted gene co-expression network, 13 co-expression modules were identified. The turquoise module contained a large number of differential expressed lncRNAs, which were mainly enriched in the PI3K-Akt signaling pathway and cAMP signaling pathway. The predicted LOC102172600 and LOC102191729 might affect the development of hair follicles and the curvature of wool by regulating the target genes. Our study provides novel insights into the potential roles of lncRNAs in the regulation of wool bending. In addition, the study offers a theoretical basis for further study of goat wool growth, so as to be a guidance and reference for breeding and improvement in the future. [ABSTRACT FROM AUTHOR]

Homozygosity of long sequence genotypes are a result of parents transmitting identical haplotypes, which can be used to estimate their auto-zygosity. Therefore, we used high-density SNP Chip data to characterize the auto-zygosity of each breed according to the occurrence and distribution of runs of homozygosity (ROH). Subsequently, we identified the genomic regions with high runs of homozygosity frequencies within individuals of each breed. We selected 96 sheep samples from five local Chinese sheep breeds belonging to different geographical locations. We identified 3046 ROHs within the study breed individuals, among which the longer segments (>1–5 Mb) were dominant. On average, ROH segments covered about 12% of the genomes; the coverage rate of OAR20 was the lowest and that of OAR2 was the highest. The distribution analysis of runs of homozygosity showed that the detected ROH mainly distributed between >26 and 28 Mb. The Hetian and Hu sheep showed the lowest ROH distribution. The estimation of homozygosity level reflects the history of modern and ancient inbreeding, which may affect the genomes of Chinese indigenous sheep breeds and indicate that some animals have experienced recent self-pollination events (Yabuyi, Karakul and Wadi). In these sheep breeds, the genomic regions were assumed to be under selection signatures frequently in line with long ROH. These regions included candidate genes associated with disease resistance traits (5S_rRNA), the innate and adaptive immune response (HERC2 and CYFIP1), digestion and metabolism (CENPJ), growth (SPP1), body size and developments (GJB2 and GJA3). This study highlighted new insights into the ROH patterns and provides a basis for future breeding and conservation strategies of Chinese sheep breeds. [ABSTRACT FROM AUTHOR]

The Zhongwei goat is an important and unique goat breed indigenous to China. It has a natural hair curling phenotype at birth, but the degree of curling gradually decreases with growth. The molecular mechanism underlying the dynamic changes in the wool curvature in Zhongwei goats is poorly understood. MicroRNAs (miRNAs) play important roles in many biological processes, including hair growth and development. In this study, we selected skins from Zhongwei goats at different ages (45 and 108 days) that exhibited different levels of hair curvature and performed miRNA sequencing to explore the molecular mechanism of hair bending. In total, 28 significantly differentially expressed miRNAs (DE miRNAs) were identified in the three groups of samples between the two developmental stages. An analysis of the target genes of the above-mentioned DE miRNAs by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated that the DE miRNAs were involved in signal pathways which were previously associated with hair bending and hair follicle development, such as the TGF-β/SMAD, PI3K-Akt, JAK-STAT, and MAPK pathways. A comprehensive analysis of the correlations between the miRNA-seq results and issued transcriptional findings indicated that SMAD1 was a target gene of miR-26a and SMAD5 was a target gene of miR-130a. Furthermore, goat dermal papilla cells were successfully isolated and purified to determine the role of miRNAs in follicle development in vitro. The study results demonstrated that miR-130a and miR-26a had significant effects on the proliferation of dermal papilla cells. In addition, the detection results of mRNA and protein levels indicate that the overexpression of miR-26a can promote the expression of related genes in the TGF-β/SMAD pathway, while miR-130a has the opposite substitution effect. The dual luciferase report test showed that miR-26a targeted the SMAD1 gene and reduced the expression of the SMAD1 protein in hair papillary cells. Our results identified DE microRNAs which perhaps change at the time of hair straightening in Zhongwei goats and explore the role of miR-26a and miR-130a in dermal papilla cells proliferation. The present study provided a theoretical basis to explore the mechanisms underlying the Zhongwei hair growth and curly phenotype. [ABSTRACT FROM AUTHOR]

Conservation of genetic resources is of great concern globally to maintain genetic diversity for sustainable food security. Comprehensive identification of the breed composition, estimation of inbreeding and effective population size are essential for the effective management of farm animal genetic resources and to prevent the animals from genetic erosion. The Zhongwei male (ZWM), Arbas Cashmere male (ACM) and Jining Grey male (JGM) goats are conserved in three different state goat farms in China but their family information, level of inbreeding and effective population size are unknown. We investigated the genomic relationship, inbreeding coefficient and effective population size in these three breeds from three state goat farms using the Illumina goat SNP50 BeadChip. Genomic relationships and phylogenetic analysis revealed that the breeds are clearly separated and formed separate clusters based on their genetic relationship. We obtained a high proportion of informative SNPs, ranging from 91.8% in the Arbas Cashmere male to 96.2% in the Jining Grey male goat breeds with an average mean of 96.8%. Inbreeding, as measured by FROH, ranged from 1.79% in ZWM to 8.62% in ACM goat populations. High FROH values, elevated genomic coverage of very long ROH (>30 Mb) and severe decline in effective population size were recorded in ACM goat farm. The existence of a high correlation between FHOM and FROH indicates that FROH can be used as an alternative to inbreeding estimates in the absence of pedigree records. The Ne estimates 13 generations ago were 166, 69 and 79 for ZWM, ACM and JGM goat farm, respectively indicating that these goat breeds were strongly affected by selection pressure or genetic drift. This study provides insight into the genomic relationship, levels of inbreeding and effective population size in the studied goat populations conserved in the state goat farms which will be valuable in prioritizing populations for conservation and for developing suitable management practices for further genetic improvement of these Chinese male goats. [ABSTRACT FROM AUTHOR]

Through long term natural and artificial selection, domestic sheep (Ovis aries) have become adapted to a diverse range of agro-ecological environments and display multiple phenotypic traits. Characterization of diversity and selection signature is essential for genetic improvement, understanding of environmental adaptation, as well as utilization and conservation of sheep genetic resources. Here, we aimed to assess genomic diversity, population structure, and genomic selection among five Chinese native sheep breeds using 600K high density SNP genotypes. A total of 96 animals of the five breeds were selected from different geographical locations with extremely dry or humid conditions. We found a high proportion of informative SNPs, ranging from 93.3% in Yabuyi to 95.5% in Wadi, Hu, and Hetian sheep. The average pairwise population differentiation (FST) between the breeds was 0.048%, ranging from 0.022% to 0.054%, indicating their low to moderate differentiation. PCA, ADMIXTURE, and phylogenetic tree analyses revealed a clustering pattern of the five Chinese sheep breeds according to their geographical distribution, tail type, coat color, body size, and breeding history. The genomic regions under putative selection identified by FST and XP-EHH approaches frequently overlapped across the breeds, and spanned genes associated with adaptation to extremely dry or humid environments, innate and adaptive immune responses, and growth, wool, milk, and reproduction traits. The present study offers novel insight into genomic adaptation to dry and humid climates in sheep among other domestic animals and provides a valuable resource for further investigation. Moreover, it contributes useful information to sustainable utilization and conservation of sheep genetic resources. [ABSTRACT FROM AUTHOR]

Simple Summary: The Ningqiang pony (NQ) is a famous breed with an average adult height at the withers (the ridge between horse's shoulder blades) of less than 106 cm, but the genetic mechanism responsible for its small stature remains unclear. Research on Chinese pony breeds is a topic of theoretical and practical importance. Long non-coding RNA (lncRNA) has been shown to regulate many biological functions, including growth. Our study, for the first time, reports the lncRNAs transcribed in horse placentas. By comparing 3011 transcripts coding 1464 lncRNAs from NQ ponies and Yili horses (YL) with distinct body sizes, six (TBX3 (T-box3), CACNA1F (L-type voltage-dependent calcium channel a1F), EDN3 (endothelin-3), KAT5 (histone acetyltransferase KAT5), ZNF281 (zinc finger protein 281), TMED2 (transmembrane emp24 domain), and TGFB1 (transforming growth factor beta 1)) out of the 233 genes targeted by differentially expressed lncRNAs were identified as being involved in limb development, skeletal myoblast differentiation, and embryo development. These results provide new insights into the genetic architecture of horse body size. As a nutrient sensor, the placenta plays a key role in regulating fetus growth and development. Long non-coding RNAs (lncRNAs) have been shown to regulate growth-related traits. However, the biological function of lncRNAs in horse placentas remains unclear. To compare the expression patterns of lncRNAs in the placentas of the Chinese Ningqiang (NQ) and Yili (YL) breeds, we performed a transcriptome analysis using RNA sequencing (RNA-seq) technology. NQ is a pony breed with an average adult height at the withers of less than 106 cm, whereas that of YL is around 148 cm. Based on 813 million high-quality reads and stringent quality control procedures, 3011 transcripts coding for 1464 placental lncRNAs were identified and mapped to the horse reference genome. We found 107 differentially expressed lncRNAs (DELs) between NQ and YL, including 68 up-regulated and 39 down-regulated DELs in YL. Six (TBX3, CACNA1F, EDN3, KAT5, ZNF281, TMED2, and TGFB1) out of the 233 genes targeted by DELs were identified as being involved in limb development, skeletal myoblast differentiation, and embryo development. Two DELs were predicted to target the TBX3 gene, which was found to be under strong selection and associated with small body size in the Chinese Debao pony breed. This finding suggests the potential functional significance of placental lncRNAs in regulating horse body size. [ABSTRACT FROM AUTHOR]

Simple Summary: Sheep is one of the most economically important animals used as a source of meat, milk, wool, and fur for human society. These commodities are essential for human being. Body growth, body weight, carcass quality, fat percent, fertility, milk yield, wool, horn type and coat color are essential and useful sheep traits. Understanding the genetic background of these traits is paramount to increase the production and productivity of domestic animals. The availability of genomic data, development of molecular breeding techniques, and genome technologies have come to play a vital role in understanding the genetic background of different animal traits. This is directly or indirectly helpful for the practice of genetic improvement of economically important traits in sheep. The identification of genomic regions, genes associated with phenotypic traits, and description of gene function are some of the applied research activities to understand the genetics of livestock species. The aim of this review is to discuss and summarize different reported research findings on identified genomic regions and candidate genes related with economically important traits as well as gene annotation in sheep. Sheep (Ovis aries) is one of the most economically, culturally, and socially important domestic animals. They are reared primarily for meat, milk, wool, and fur production. Sheep were reared using natural selection for a long period of time to offer these traits. In fact, this production system has been slowing the productivity and production potential of the sheep. To improve production efficiency and productivity of this animal through genetic improvement technologies, understanding the genetic background of traits such as body growth, weight, carcass quality, fat percent, fertility, milk yield, wool quality, horn type, and coat color is essential. With the development and utilization of animal genotyping technologies and gene identification methods, many functional genes and genetic variants associated with economically important phenotypic traits have been identified and annotated. This is useful and presented an opportunity to increase the pace of animal genetic gain. Quantitative trait loci and genome wide association study have been playing an important role in identifying candidate genes and animal characterization. This review provides comprehensive information on the identified genomic regions and candidate genes associated with production and reproduction traits, and gene function in sheep. [ABSTRACT FROM AUTHOR]

Detection of selection footprints provides insight into the evolution process and the underlying mechanisms controlling the phenotypic diversity of traits that have been exposed to selection. Selection focused on certain characters, mapping certain genomic regions often shows a loss of genetic diversity with an increased level of homozygosity. Therefore, the runs of homozygosity (ROHs), homozygosity by descent (HBD), and effective population size (Ne) are effective tools for exploring the genetic diversity, understanding the demographic history, foretelling the signature of directional selection, and improving the breeding strategies to use and conserve genetic resources. We characterized the ROH, HBD, Ne, and signature of selection of six Chinese goat populations using single nucleotide polymorphism (SNP) 50K Illumina beadchips. Our results show an inverse relationship between the length and frequency of ROH. A long ROH length, higher level of inbreeding, long HBD segment, and smaller Ne in Guangfeng (GF) goats suggested intensive selection pressure and recent inbreeding in this breed. We identified six reproduction-related genes within the genomic regions with a high ROH frequency, of which two genes overlapped with a putative selection signature. The estimated pair-wise genetic differentiation (FST) among the populations is 9.60% and the inter- and intra-population molecular variations are 9.68% and 89.6%, respectively, indicating low to moderate genetic differentiation. Our selection signatures analysis revealed 54 loci harboring 86 putative candidate genes, with a strong signature of selection. Further analysis showed that several candidate genes, including MARF1, SYCP2, TMEM200C, SF1, ADCY1, and BMP5, are involved in goat fecundity. We identified 11 candidate genes by using cross-population extended haplotype homozygosity (XP-EHH) estimates, of which MARF1 and SF1 are under strong positive selection, as they are differentiated in high and low reproduction groups according to the three approaches used. Gene ontology enrichment analysis revealed that different biological pathways could be involved in the variation of fecundity in female goats. This study provides a new insight into the ROHs patterns for maintenance of within breed diversity and suggests a role of positive selection for genetic variation influencing fecundity in Chinese goat. [ABSTRACT FROM AUTHOR]

A series of complex processes regulate muscle development, and lncRNAs play essential roles in the regulation of skeletal myogenesis. Using RNA sequencing, we profiled the lncRNA expression during goat (Capra hircus) skeletal muscle development, which included seven stages across fetal 45 (F45), 65 (F65), 90 (F90), 120 (F120), 135 (F135) days, born for 24 h (B1) and 90 (B90) days. A total of 15,079 lncRNAs were identified in the seven stages, and they were less conservative with other species (human, cow, and mouse). Among them, 547 were differentially expressed, and they divided the seven stages into three functional transition periods. Following weighted gene co-expression network analysis (WGCNA), five lncRNA modules specific for developmental stages were defined as three types: 'Early modules', 'late modules', and 'individual-stage-specific modules'. The enrichment content showed that 'early modules' were related to muscle structure formation, 'late modules' participated in the 'p53 signaling pathway' and other pathways, the F90-highly related module was involved in the 'MAPK signaling pathway', and other pathways. Furthermore, we identified hub-lncRNA in three types of modules, and LNC_011371, LNC_ 007561, and LNC_001728 may play important roles in goat skeletal muscle. These data will facilitate further exploration of skeletal muscle lncRNA functions at different developmental stages in goats. [ABSTRACT FROM AUTHOR]

Simple Summary: Information on linkage disequilibrium (LD) and the extent of effective population size (Ne) has important implications for exploring the degree of biological diversity, for predicting underlying selection pressure, and for designing animal breeding programs. In this study, we assessed LD, Ne, and the distribution of minor allele frequency in six goat populations. Accordingly, the results of LD and Ne using a single nucleotide polymorphism (SNP) panel (Caprine SNP 50K BeadChip, Lincoln, NE, USA) are helpful for the sustainable conservation, proper management, and utilization of Chinese goat populations. Genome-wide linkage disequilibrium is a useful parameter to study quantitative trait locus (QTL) mapping and genetic selection. In many genomic methodologies, effective population size is an important genetic parameter because of its relationship to the loss of genetic variation, increases in inbreeding, the accumulation of mutations, and the effectiveness of selection. In this study, a total of 193 individuals were genotyped to assess the extent of LD and Ne in six Chinese goat populations using the SNP 50K BeadChip. Across the determined autosomal chromosomes, we found an average of 0.02 and 0.23 for r2 and D' values, respectively. The average r2 between all the populations varied little and ranged from 0.055 r2 for the Jining Grey to 0.128 r2 for the Guangfeng, with an overall mean of 0.083. Across the 29 autosomal chromosomes, minor allele frequency (MAF) was highest on chromosome 1 (0.321) and lowest on chromosome 25 (0.309), with an average MAF of 0.317, and showing the lowest (25.5% for Louping) and highest (28.8% for Qingeda) SNP proportions at MAF values > 0.3. The inbreeding coefficient ranged from 0.064 to 0.085, with a mean of 0.075 for all the autosomes. The Jining Grey and Qingeda populations showed higher Ne estimates, highlighting that these animals could have been influenced by artificial selection. Furthermore, a declining recent Ne was distinguished for the Arbas Cashmere and Guangfeng populations, and their estimated values were closer to 64 and 95, respectively, 13 generations ago, which indicates that these breeds were exposed to strong selection. This study provides an insight into valuable genetic information and will open up the opportunity for further genomic selection analysis of Chinese goat populations. [ABSTRACT FROM AUTHOR]

Simple Summary: Heat stress is an intriguing factor that negatively influences livestock production and reproduction performance. Sheep and goat are among the livestock that can adapt to environmental heat stress via a combination of physiological, morphological, behavioral, and genetic bases. Sheep and goat are able to minimize adverse effect of high thermal stress by invoking behavioral responses such as feeding, water intake, shade seeking, and increased frequency of drinking. Their morphological mechanisms are comprised of body shape and size, light hair color, lightly pigmented skin, and less subcutaneous fat, and the physiological means are that of increased respiration rate (RR), increased sweating rate (SW), reduced metabolic rate, and change in endocrine function. Adaptation in terms of genetics is the heritable trait of animal characteristics which favor the survival of populations. For instance, genes like heat shock proteins 70 (HSP70) and ENOX2 are commonly expressed proteins which protect animals against heat stress. Small ruminants are the critical source of livelihood for rural people to the development of sustainable and environmentally sound production systems. They provided a source of meat, milk, skin, and fiber. The several contributions of small ruminants to the economy of millions of rural people are however being challenged by extreme heat stress difficulties. Heat stress is one of the most detrimental factors contributing to reduced growth, production, reproduction performance, milk quantity and quality, as well as natural immunity, making animals more vulnerable to diseases and even death. However, small ruminants have successfully adapted to this extreme environment and possess some unique adaptive traits due to behavioral, morphological, physiological, and largely genetic bases. This review paper, therefore, aims to provide an integrative explanation of small ruminant adaptation to heat stress and address some responsible candidate genes in adapting to thermal-stressed environments. [ABSTRACT FROM AUTHOR]

We recently isolated stem cells derived from the brain of a bovine fetus, utilizing a particular mechanical separation method. After improving our experimental conditions, we obtained neural stem cells using an optimized culture medium system. The cells were expanded, established in continuous cell culture and used for immunofluorescence cytochemistry. RT-PCR showed that embryonic neural stem cells (NSCs) not only expresses the protein Sox2, Nestin but also Pax6, Musashi proteins and were differentiated into the three classical neuronal phenotypes (neurons, astrocytes, and oligodendrocytes).

Bacterial artificial chromosome (BAC) libraries are extremely valuable for the genome-wide genetic dissection of complex organisms. The Siberian tiger, one of the most well-known wild primitive carnivores in China, is an endangered animal. In order to promote research on its genome, a high-redundancy BAC library of the Siberian tiger was constructed and characterized. The library is divided into two sub-libraries prepared from blood cells and two sub-libraries prepared from fibroblasts. This BAC library contains 153,600 individually archived clones; for PCR-based screening of the library, BACs were placed into 40 superpools of 10 × 384-deep well microplates. The average insert size of BAC clones was estimated to be 116.5 kb, representing approximately 6.46 genome equivalents of the haploid genome and affording a 98.86% statistical probability of obtaining at least one clone containing a unique DNA sequence. Screening the library with 19 microsatellite markers and a SRY sequence revealed that each of these markers were present in the library; the average number of positive clones per marker was 6.74 (range 2 to 12), consistent with 6.46 coverage of the tiger genome. Additionally, we identified 72 microsatellite markers that could potentially be used as genetic markers. This BAC library will serve as a valuable resource for physical mapping, comparative genomic study and large-scale genome sequencing in the tiger.

The use of amnion and amniotic fluid (AF) are abundant sources of mesenchymal stem cells (MSCs) that can be harvested at low cost and do not pose ethical conflicts. In human and veterinary research, stem cells derived from these tissues are promising candidates for disease treatment, specifically for their plasticity, their reduced immunogenicity, and high anti-inflammatory potential. This work aimed to obtain and characterize bovine amniotic fluid mesenchymal stem cells (AFMSC). The bovine AF from the amniotic cavity of pregnant gilts in the early stages of gestation (3- and 4-m-old bovine embryos) was collected. AFMSCs exhibit a fibroblastic-like morphology only starting from the fourth passage, being heterogeneous during the primary culture. Immunofluorescence results showed that AFMSCs were positive for β-integrin, CD44, CD73 and CD166, but negative for CD34, CD45. Meanwhile, AFMSCs expressed ES cell markers, such as Oct4, and when appropriately induced, are capable of differentiating into ectodermal and mesodermal lineages. This study reinforces the emerging importance of these cells as ideal tools in veterinary medicine; future studies aimed at a deeper evaluation of their immunological properties will allow a better understanding of their role in cellular therapy.

In this study, a full-length enriched cDNA library was successfully constructed from Bengal tiger, Panthera tigris tigris, the most well-known wild Animal. Total RNA was extracted from cultured Bengal tiger fibroblasts in vitro. The titers of primary and amplified libraries were 1.28 × 106 pfu/mL and 1.56 × 109 pfu/mL respectively. The percentage of recombinants from unamplified library was 90.2% and average length of exogenous inserts was 0.98 kb. A total of 212 individual ESTs with sizes ranging from 356 to 1108 bps were then analyzed. The BLASTX score revealed that 48.1% of the sequences were classified as a strong match, 45.3% as nominal and 6.6% as a weak match. Among the ESTs with known putative function, 26.4% ESTs were found to be related to all kinds of metabolisms, 19.3% ESTs to information storage and processing, 11.3% ESTs to posttranslational modification, protein turnover, chaperones, 11.3% ESTs to transport, 9.9% ESTs to signal transducer/cell communication, 9.0% ESTs to structure protein, 3.8% ESTs to cell cycle, and only 6.6% ESTs classified as novel genes. By EST sequencing, a full-length gene coding ferritin was identified and characterized. The recombinant plasmid pET32a-TAT-Ferritin was constructed, coded for the TAT-Ferritin fusion protein with two 6× His-tags in N and C-terminal. After BCA assay, the concentration of soluble Trx-TAT-Ferritin recombinant protein was 2.32 ± 0.12 mg/mL. These results demonstrated that the reliability and representativeness of the cDNA library attained to the requirements of a standard cDNA library. This library provided a useful platform for the functional genome and transcriptome research of Bengal tigers.