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Gli3 is a zinc finger transcription factor which plays a critical role in regulating animal development, metabolism and energy partitioning and thus has the potential to influence economical important traits in farm animals. In this study, we screened the complete exons of the caprine Gli3 gene using PCR-SSCP methods in 430 individuals from three goat breeds to identify sequence variants that might be associated with growth traits. Six novel mutations (GU363952:g.739C>G, 749A>T, 1636C>A, 1982delT, 1983T>C, 2856T>C) were identified. Significant associations were observed between the mutations GU363952:g.739C>G and g.749A>T with body height, chest circumference and canon circumference. Individuals with genotype G4-CC/AA and G4-CG/AT were significantly higher than individuals with genotype G4-GG/TT in body height, chest circumference and canon circumference. The results of this study suggested that the Gli3-gene-specific SNP could be a useful marker for growth traits in future marker-assisted selection programs in goat. [ABSTRACT FROM AUTHOR]

method was depicted to identify null allele CSN1S1 N and low allele CSN1S1 F of the CSN1S1 gene of goat using PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism). First, primer A was designed to amplify the exon 9 of CSN1S1 gene which produced three genotypes AA, AB, and BB. Among these three genotypes, only AA and AB individuals had a cytosine deletion at exon 9 after DNA sequencing, which cannot be used to identify the N and F alleles. Therefore, primer B was used to amplify intron 14 of CSN1S1 of described AA and AB individuals. Genotypes FF, FN and NN were detected within AA individuals and genotypes FO and NO were detected in the above AB individuals. The frequencies of F and N alleles in 708 samples from Xinong Saanen (XS) and Guanzhong (GZ) dairy goat breeds were 0.1139, 0.0927, and 0.2376, 0.1193, respectively. In 268 XS samples, the individuals with NN genotype contained a significant lower protein content than that of other genotypes ( P < 0.01). Individuals of FF genotype had significant higher milk yield than that of NO genotype in the first milk lactation of 202 XS individuals ( P < 0.05). Therefore, the variability at CSN1S1 locus contains enough genetic diversity to be potentially useful in improving the quality and production of milk in Chinese dairy goat breeds. [ABSTRACT FROM AUTHOR]

DLK1 and CLPG were located in DLK1- GTL2 imprinted cluster. They all affected muscle growth and meat tenderness. The functional importance of DLK1 and CLPG imply that the variation of the genes could affect the growth traits of animal. PCR-SSCP and sequencing were used to analyze the four loci of DLK1 gene and CLPG gene in 1109 individuals, which belong to eight breeds/species of bovidae, including cattle, buffalo and yak. A synonymous mutation (C451T) was detected in exon 5 of DLK1 in Qinchuan cattle, but didn't change significantly with phenotypic traits. Three genotypes AA, AB and AC of CLPG were identified in Jiaxian cattle. The associations analyst of different genotypes showed that the individuals with genotypes AA and AC had a greater body weight and longer body length than those with genotype AB ( P < 0.05 and P < 0.01, respectively); the AA individuals were different from those AB ( P < 0.05) in the circumference of cannon bone. No polymorphism was observed in the other populations at other loci. These results were in agreement with the homology analysis: DLK1 and CLPG genes were in a highly conserved. [ABSTRACT FROM AUTHOR]

Abstract  In this study, polymorphism in the exon 1, 2, 3, 4 and 5 of bovine GAD1 gene was detected by PCR–SSCP and DNA sequencing methods in 726 individuals from three Chinese cattle breeds. Two haplotypes (T and C) and three observed genotypes (TT, TC, and CC) were detected. The result of DNA sequence showed one mutations (T12345C) by comparisons with NC_007300: g.12345T>C. The mutation was at the exon 3, and was identified a missense mutation Phe (TTT)>Leu (CTT) at position 51 (p.F51L). Polymorphism of the GAD1 gene was shown to be associated with growth traits in the Nanyang breed. The SNP in the bovine GAD1 gene had significant effects on body length, body weight, heart girth, and average daily gain at 24 months (P  [ABSTRACT FROM AUTHOR]

Abstract  In this study, polymorphism in the exon 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11 of bovine NUCB2 gene was detected by PCR-SSCP and DNA sequencing methods in 686 individuals from three Chinese cattle breeds. Two haplotypes (M and N), three observed genotypes (MM, MN and NN) and two SNPs (NC_007313: g. 27451G>A, NC_007313: g. 27472T>C) were detected. The frequencies of haplotypes M and N in inland Chinese three breeds were 0.531–0.721 and 0.279–0.469 respectively. The studied showed that Nanyang, Jiaxian Red and Qinchuan cattle populations were in Hardy–Weinberg equilibrium at SNPs locus of NUCB2 gene (P > 0.05). Polymorphism of the NUCB2 gene was shown to be associated with growth traits in Qingchuan and Nanyang cattle breed. The linkage of two mutant sites in the bovine NUCB2 gene had significant effects on body length, body weight, heart girth, and average daily gain at 24 months (P NUCB2-gene-specific SNP may be a useful marker for growth traits in future marker-assisted selection programmes in inland Chinese cattle. [ABSTRACT FROM AUTHOR]

Identification of polymorphisms associated with economic traits is important for successful marker-assisted selection in cattle breeding. The family of mammalian sirtuin regulates many biological functions, such as life span extension and energy metabolism. SIRT2, a most abundant sirtuin in adipocytes, acts as a crucial regulator of adipogenic differentiation and plays a key role in controlling adipose tissue function and mass. Here we investigated single nucleotide polymorphisms (SNPs) of bovine SIRT2 in 1226 cattle from five breeds and further evaluated the effects of identified SNPs on economically important traits of Nanyang cattle. Our results revealed four novel SNPs in bovine SIRT2, one was located in intronic region and the other three were synonymous mutations. Linkage disequilibrium and haplotype analyses based on the identified SNPs showed obvious difference between crossbred breed and the other four beef breeds. Association analyses demonstrated that SNPs g.17333C > T and g.17578A > G have a significantly effect on 18-months-old body weight of Nanyang population. Animals with combined genotype TTGG at the above two loci exhibited especially higher body weight. Our data for the first time demonstrated that polymorphisms in bovine SIRT2 are associated with economic traits of Nanyang cattle, which will be helpful for future cattle selection practices.

Paired box 3 (PAX3) belongs to the PAX superfamily of transcription factors and plays essential roles in the embryogenesis and postnatal formation of limb musculature through affecting the survival of muscle progenitor cells. By genetic mapping, PAX3 gene is assigned in the interval of quantitative trait loci for body weight on bovine BTA2. The objectives of this study were to detect polymorphisms of PAX3 gene in 1,241 cattle from five breeds and to investigate their effects on growth traits. Initially, three novel single nucleotide polymorphisms (SNPs) were identified by DNA pool sequencing and aCRS-RFLP methods (AC&#95;000159: g.T-580G, g.A4617C and g.79018Ins/del G), which were located at 5'-UTR, exon 4 and intron 6, respectively. A total of eight haplotypes were constructed and the frequency of the three main haplotypes H1 (TAG), H2 (GCG) and H3 (GAG) accounted for over 81.7 % of the total individuals. Statistical analysis revealed that the three SNPs were associated with body height and body length of Nanyang and Chinese Caoyuan cattle at the age of 6 and/or 12 months old (P < 0.05), and consistently significant effects were also found in the haplotype combination analysis on these traits (P < 0.05). This study presented a complete scan of variations within bovine PAX3 gene, which could provide evidence for improving the economic traits of cattle by using these variations as potentially genetic markers in early marker-assisted selection programs.

The peroxisome proliferator-activated receptor gamma coactivator-1 alpha protein, encoded by the PPARGC1A gene, is a metabolic switch, which transcriptionally activates a complex pathway of mitochondrial biogenesis, lipid and glucose metabolism. Three SNPs (exon 3 c.396G>A, intron 9 c.1892 + 19C>T and exon 10 c.1971C>T) were found and identified in three Chinese native cattle breeds by PCR-SSCP, PCR-RFLP and DNA sequencing methods. All three populations had a low genetic diversity at SNP396 locus (PIC <0.25) while possessed a moderate genetic diversity at SNP1892 locus (0.25 < PIC < 0.5). Association study indicated that the synonymous mutation c.396G>A significantly associated with body weight and average daily gain in Nanyang cattle at the adult age (P < 0.05). Our investigation will not only extend the spectrum of genetic variation of bovine PPARGC1A gene, but also provide useful information for the marker assisted selection in beef cattle breeding program.

Cell death-inducing DFFA-like effector c (CIDEC) protein, also known as fat specific protein 27 (Fsp27), is localized to lipid droplets. CIDEC protein is required for unilocular lipid droplet formation and optimal energy storage in addition to controlling lipid metabolism in adipocytes and hepatocytes. Research found that Ad-36 could induce lipid droplets in the cultured skeletal muscle cells and this process may be mediated by promoting CIDEC expression. The content of intermuscular fat is an important index for evaluation of beef quality, so the CIDEC gene appeared to be a candidate gene for regulation of intermuscular fat, however similar research for the bovine CIDEC gene is lacking. This paper examined the tissue expression profile of CIDEC gene in cattle using real-time RT-PCR to suggest that bovine CIDEC is highly expressed in adipose tissue. In addition, the Bovine CIDEC gene was cloned and inserted into the eukaryotic expression vector pET-28a(+), whereupon recombinant bovine CIDEC protein was induced and identified by Western-blot. A phylogenetic analysis showed that the animo acid sequence of bovine CIDEC was closer to mammalian CIDEC than rasorial CIDEC. We found ten single nucleotide polymorphisms sites (SNPs) in bovine CIDEC gene, of which SNP 2, 3, 4, 6 and 9, and SNP 8 and 10 were in complete linkage disequilibrium, respectively. SNP 1, 2 and 10 were used in further haplotype studies. Eight different haplotypes were identified in 973 cattle, of which haplotype 8 predominated with frequencies ranging from 42.90 to 54.30 %. This research provides a basis for future functional studies of CIDEC in cattle.

Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an interesting novel adipocytokine with insulin-sensitizing effects. Some studies have suggested that vaspin could play an important role in the development of obesity and metabolic disorders. However, the tissue expression patterns in cattle and impact of vaspin gene variants on the growth traits has not been determined yet. Herein, we firstly investigated the tissue expression patterns of vaspin gene in new born and adult cattle. The results showed that vaspin was ubiquitously expressed in most tissues and strongly expressed in the heart, skeletal muscle and fat. Then, genetic variants within bovine vaspin gene were screened in 1235 individuals from five Chinese indigenous cattle breeds. Two novel mutations in coding region (NW&#95;001494061: g.1124477 G>A and g.1118561 T>C) of bovine vaspin gene were identified using MspI PCR-RFLP and HhaI ACRS PCR-RFLP detection. Association analysis revealed both two mutations were significantly associated with bodyweight and chest girth at 24 months in cattle (P < 0.05). Therefore, the MspI and HhaI genetic variants of bovine vaspin gene were recommended as DNA markers related to growth traits through marker-assisted selection for genetics and breeding in cattle.

MYST histone acetyltransferase 2 (MYST2) is an important reproduction related gene. In this study, we cloned the full-length cDNA sequence of porcine MYST2 gene through the rapid amplification of cDNA ends method. The porcine MYST2 gene encodes a protein of 611 amino acids which shares high homology with the MYST2 of six species: cattle (99%), rabbit (99%), human (99%), rat (99%), mouse (99%) and chicken (98%).The open reading frame of this gene is structured in 15 exons and 14 introns as revealed by computer-assisted analysis. The phylogenetic analysis revealed that the porcine MYST2 gene has a closer genetic distance with the MYST2 gene of cattle. PCR-RFLP was established to detect the GU373686:c.2872G > A substitution of porcine MYST2 gene mRNA and association of this mutation with litter size traits was assessed in Large White (n = 200) and Landrace (n = 200) pig populations. Results demonstrated that this polymorphic locus was significantly associated with the litter size of all parities in Large White sows and Landrace sows. These data serve as a foundation for further insight into this porcine gene.

Ablation of AdPLA in mice could prevent obesity, which implicated AdPLA was a new candidate gene for growth traits. In this study, we screened the polymorphisms of AdPLA gene and revealed three novel SNPs (NC&#95;007330.4:g.43638506 C>T, 43658457 T>C and 43661404 T>C) by DNA sequencing and forced PCR-RFLP methods in 1340 individuals from six breeds. A preliminary single SNP-traits association analysis demonstrated that CC genotype was significantly higher than TT genotype at two growth traits in P6-EcoRII locus (P < 0.05). Moreover, the P8-FbaI locus had a significant association with some growth traits, individuals with TT genotype were higher than CC genotype (P < 0.05). A further analysis confirmed that these two SNPs were in linkage disequilibrium, and haplotype H2, both advantage allelic in P6-EcoRII and P8-FbaI loci, was better than the others for bovine growth traits, which was consistent with single SNP-traits association results. Therefore, this study not only proved that these SNPs were in association with bovine growth traits, but also contributed to evaluate them as genetic markers in bovine genetics and breeding and had potential application in breeding programs.

In this study, genetic variability at codon 42 within prion protein (PRNP) gene and its associations with production traits were investigated in 2002 goats from four Chinese domestic breeds. The frequencies of allele "A" ranged from 0.353 to 0.562 in analyzed goat breeds with Hardy-Weinberg equilibrium (P > 0.05) except Xinong Sannen (XNSN) dairy breed. The establishment of relationships between different genotypes and growth traits was performed in Inner Mongolia white Cashmere (IMWC) breed and revealed an association of the polymorphism with body weight at 7-year-old goats (P = 0.033). The individuals with genotype GG showed heavier body weight than those with genotype AA. Moreover, association analysis detected two significant associations between different genotypes and cashmere yield and fiber length in IMWC breed (P = 0.009, P = 0.048, respectively). In addition, three significant associations of different genotypes with density of milk (a.m. and p.m.), solids-not-fat of milk (P = 0.013, P = 0.009 and P = 0.002), respectively, were found in XNSN breed. Genotype GG had better milk quality than others. These findings suggested that the polymorphism of codon 42 within PRNP was a useful DNA marker for eliminating or selecting excellent individuals in relation to production traits in marker-assist selection breeding of goat.

Retinoic acid receptor responder 2 gene (RARRES2) encodes a novel adipokine protein that plays a crucial role in regulating several biological processes, including immune responses, adipocyte differentiation, type 2 diabetes and metabolic syndrome. In this paper, polymorphisms of the bovine RARRES2 gene were detected in 1300 individuals from six breeds by DNA pooling, CRS-PCR-RFLP and DNA sequencing methods. The results showed that NC&#95;007302:g.117035859A>G, 117035706G>A and 117034290A>G were in the coding region, which resulted in three synonymous mutations and only 117033779C>G was in the 3' UTR. Additionally, associations of the four novel SNPs with growth traits were analyzed in Nanyang cattle up to 2 years of age. In P1-PvuII locus, individuals with genotype BC had greater body height and hucklebone width than those with genotype AA, AC and AB at the age of 24 months. In P3-BamHI locus, individuals with genotype AG had higher hucklebone width than those with genotype GG at the age of 24 months. However, no statistically significant differences were observed in P5-SmaI locus. These results indicated that RARRES2 gene might be a potential candidate gene for marker-assisted selection (MAS).

Transgenically expressed Syndecan-1 was found in the hypothalamic nuclei that control energy balance, and was associated with maturity-onset obesity, while ghrelin has been shown to play important roles in the control of food intake, gastric acid secretion, energy homeostasis, and glucose and lipid metabolism. However, the roles of genetic variations of Syndecan-1 and ghrelin on growth trait have few been reported in cattle. Herein, five Chinese cattle breeds were analyzed by PCR-SSCP and DNA sequencing methods. The bovine ghrelin gene showed eleven SNPs g.[267G>A, 271G>A, 290C>T, 326A>G, 327T>C, 420C>A, 569A>G, 945C>T, 993C>T, 4491A>G, 4644G>A] and three SNPs g.[420C>A, 569 A>G, 945C>T] were firstly detected in cattle. The bovine Syndecan-1 gene showed two SNPs. One SNP showed a transition C>G at position 21514, resulting in a synonymous mutation p.G(GGC)169G(GGG) and another showed a transversion C>T at position 22591, resulting in a synonymous mutation p.D(GAC)283D(GAT). In ghrelin gene, no significant associations were revealed between any variant sites and body weight, average daily gain, body sizes for different growth periods (6, 12, 18, and 24 months old), as well as for the milk yield at 305 days, milk protein rate and milk fat percentage. However, the polymorphism of Syndecan-1 gene was significantly associated with bovine birth weight and body length. Hence, we first suggested that Syndecan-1 gene could be regarded as molecular marker for superior birth weight and body length.

Stearoyl-CoA desaturase (SCD) is an iron-containing enzyme involving in the biosynthesis of monounsaturated fatty acids (MUFA) in mammary gland and adipose tissue, while decorin (DCN) consists of a protein core and a single dermatan or chondroitin sulfate glycosaminoglycan chain, contributing multifunctionally to matrix assembly, modulation of the activity of growth factors and cell migration and proliferation. However, few studies have focused on the genetic variability of them in goat. Herein, five Chinese goat breeds (1229 animals) were analyzed. Based on DNA pooling and PCR-RFLP, three nucleotide substitutions, one of which caused a amino acid substitution, were detected in SCD gene and three haploids (A, B, C) were constructed. According to SSCP analysis and DNA sequencing methods, a 2-bp deletion and two other SNPs were found existing in another analyzed gene DCN, and three haploids (X, Y, Z) were built. Associations between the genotypes and the growth traits (body length, body height, chest circumference, cannon circumference) were also analyzed. For SCD gene, genotype CC individuals had significant greater body height in Guanzhong and body length in both Guanzhong and Xinong saanen than genotype BC individuals (P < 0.05). For DCN gene, individuals with genotype XX was obviously higher than that with genotype XY (P < 0.05). These results indicated that genotype CC of SCD gene and genotype XX of DCN gene could be used for the breeding of new breeds of goat in China.

The ATP-binding cassette transporter ABCG2 (also known as breast cancer resistance protein, BCRP) belongs to the ATP-binding cassette (ABC) family of transmembrane drug transporters, playing a crucial role in the protection of various cells and tissues against xenotoxins and/or endotoxins. Recently, several studies have proposed it as the potential gene underlying the QTL on bovine chromosome 6. Hence, in this study, the PCR-SSCP method was applied to detect two polymorphisms (A → C and A → G) in the target sequence coding nucleotide-binding domain (NBD) region of ABCG2 and evaluate its associations with milk production traits and mastitis-related traits among Chinese Holsteins. In the analyzed population, the allelic frequencies for the A and B alleles were 0.5990 and 0.4010, respectively and the genotypic frequencies were in Hardy-Weinberg disequilibrium (P < 0.01). Moreover, significant statistical relationships between the polymorphisms of ABCG2 gene and following traits, including milk yields, milk protein percentage and somatic cell scores (SCS), were found (P < 0.05). When compared with AA genotype, BB genotype was associated with higher milk yields during 1st and 2nd lactations, as well as lower milk protein percentage and SCS. Thus, BB genotype is suggested to be a molecular marker for superior milk performance.

PCR-SSCP and DNA sequencing methods were employed to screen the genetic variation of vascular endothelial growth factor (VEGF) gene in 675 individuals belonging to three Chinese indigenous cattle breeds including Qinchuan (QC), Jiaxian Red (JX) and Nanyang (NY) breed. Three new single nucleotide polymorphisms (SNPs) (g.6765T > C ss130456744, g.6860A > G ss130456745, g.6893T > C ss130456746) were found. One SNP (g.6765T > C) was detected in intron II of VEGF gene in all three breeds and the other two SNPs (g.6860A > G, g.6893T > C) were in exon III of VEGF gene only in NY breed. Among them, two synonymous mutations of exon III were identified: CCA (Pro) > CCG (Pro) at position 65th amino acid (aa) and TGT (Cys) > TGC (Cys) at position 76th aa of VEGF(190aa) in NY breed. Our study revealed that NY breed exhibited the most abundant genetic diversity in VEGF gene within the three cattle breeds. Furthermore, JX cattle breed was more similar to QC breed than to NY breed. Our genetic data in the present study supported the hypothesis that the distribution pattern of Chinese indigenous cattle breeds was closely related to the geographical and climatic background again.

PCR-SSCP and DNA sequencing methods were employed to screen the genetic variation of VEGF gene in 671 individuals belonging to three Chinese indigenous cattle breeds including Nanyang, Jiaxian Red and Qinchuan. Three haplotypes (A, B and C), four observed genotypes (AA, AB, BB and AC) and three new SNPs (6765T>C ss130456744, 6860A>G ss130456745, 6893T>C ss130456746) were detected. The analysis suggested that one SNP (ss130456744) in the bovine VEGF gene had significant effects on birth weight, body weight and heart girth at 6 months old in the Nanyang breed (P < 0.05). The results showed that the SNP (ss130456744) in intron 2 of the VEGF gene is associated with early development and growth of Chinese cattle. These findings raise hope that this polymorphism can be a molecular breeding marker in breeding strategies through marker assisted selection (MAS) in Chinese domestic cattle.

Growth hormone-releasing hormone receptor (GHRHR) plays a critical role in growth hormone (GH) synthesis, release and regulation of pituitary somatotroph expansion in vertebrates. The objective of this study was to investigate variations in goat GHRHR gene and their associations with growth traits in 668 dairy goats. The results showed four novel single nucleotide polymorphisms (SNPs): NC&#95;007302:g.5203C>T, 7307C>G, 9583G>A and 9668A>C. In detail, the novel SNP C>T in the 5203rd nucleotide identified a missense mutation: CCC (Pro)>TCC (Phe) at position 116aa of the goat GHRHR (423aa). Besides, 9583G>A and 9668A>C polymorphism were in complete linkage disequilibrium. The genetic diversity analysis revealed that the Guanzhong dairy goat possessed intermediate genetic diversity in P3 and P7 loci, and the Xinong Sannen dairy goat belonged to poor genetic diversity in P4 locus. Significant associations between the genotypes of P3 locus and body length, body height and chest circumference was observed in Guanzhong goat (P<0.05). However, in Xinong saanen population, significant statistical difference was only found in body height and body length (P<0.05). In P4 and P7 loci, no significant associations were detected between any variant sites and body length, body height and chest circumference, as well as for the milk traits (P>0.05). These results strongly suggested that the goat GHRHR gene is a candidate gene that influences growth traits in dairy goat.

Butyrophilin (BTN1A1) and milk fat globule epidermal growth factor (EGF) 8 (MFG-E8) genes are both milk fat globule membrane proteins. BTN1A1 plays a key role in the secretion of milk lipid and production which has effects on performance traits, while the MFG-E8 is vital for the development of the mammary gland and phagocytic clearance of apoptotic cells. Therefore, BTN1A1 and MFG-E8 gene are candidate genes for quantitative traits in mammalian animals with respect to milk performance traits. The objective of this study is to investigate variations in goat BTN1A1 and MFG-E8 gene and analyze their associations with growth trait and milk performance. In this study, the goat BTN1A1 gene showed a novel single-nucleotide polymorphism (SNP): XM&#95;001494179:g.8659C>T, resulting in a missense mutation: CTT (Leu)>TTT (Phe) at position 377 aa of the BTN1A1 (526 aa); the goat MFG-E8 gene showed four novel SNPs: NC&#95;007319: g.843delA, 6417delC, 14892T>C and 14996A>C, only the 14892T>C result in a synonymous mutation. The associations between genotypes and production traits were analyzed. Significant statistical results implied that HinfI locus of BTN1A1 gene is associated with milk fat yield (P=0.004), total solid (P=0.002), solid-non fat (P=0.018) and first milk yield (P=0.030). The DA and EcoRV loci of MFG-E8 gene are associated with milk fat yield (DA locus: P=0.000; EcoRV locus: P=0.033) and total solid (DA locus: P=0.002; EcoRV locus: P=0.015) in the Xinong Saanen dairy goat.

HESX1 plays a key role in the development of the forebrain and pituitary gland and produces potential effects on performance traits. The objective of this study was to detect and assess the associations of the possible polymorphisms of six loci within HESX1 gene with performance traits in Chinese 1,119 goats. Only one novel SNP (NM&#95;001494116:g.307049A > G) locating on IVS1 + 348A > G was identified and detected by HaeIII forced-RFLP-PCR. The frequencies of allele "G" varied from 0.025 to 0.245 in analyzed populations with the Hardy-Weinberg equilibrium (P > 0.05). Genotypic and allelic frequencies were found to be significantly different in four breeds (chi(2) = 147.674, df = 6, P < 0.001; chi(2) = 157.250, df = 3, P < 0.001, respectively), implying that the distribution of genotypic and allelic frequencies of goat HESX1 gene was significantly associated with different goat utilities (cashmere, meat and dairy). Association analysis results revealed no significant effects of caprine HESX1 gene on body sizes in XNSN population (P > 0.05) and cashmere traits in IMWC population (P > 0.05). Significant statistical of HESX1 gene with body weight was found (*P < 0.05). The genotype AA showed significantly higher body weight than those of AG in 2-year-old age (*P < 0.05), while the AA genotype was senior to AG genotype in 4-year-old body weight trait (*P < 0.05). These suggestions indicated that the HESX1 gene has significant effect on goat body weight depending on ages, which is accordance with the function repressor of the HESX1.

As a paired class homeodomain transcription factor, mutations of PROP1 (Prophet of POU1F1) are responsible for deficiencies of GH, PRL, TSH, LH and FSH. Regarding mutations of GH, PRL, and POU1F1 genes significantly associating with different production traits, PROP1 gene is a novel important candidate gene for detecting genetic variation and association analysis in marked-assist selection (MAS) program. Therefore, the objective of this study is to detect goat PROP1 gene mutation and its association with production traits. Herein, a novel mutation (AF453512:g.1795C>T) within PROP1 gene is revealed by PCR-SSCP and DNA sequencing methods, and genotyped by Hin6I PCR-RFLP method in 1,344 individuals belonging to eight goat breeds. Only two genotypes (CC and CT) are revealed and the frequencies of allele C go from 0.9014 to 1.000 in analyzed populations. The genetic diversity analysis reveals that all PIC values are less than 0.1619, implying that the Hin6I locus within PROP1 gene possesses low genetic diversity in goat. Furthermore, nucleotide sequence analysis shows that AF453512:g.1795C>T results in a missense amino acid (A79V). But, association analysis demonstrates no significant differences between different genotypes and production traits (such as body weight, cashmere yield, fiber length and wool thickness) of Inner Mongolia White Cashmere goat (P > 0.05), as well as no significant relationship between different genotypes and average milk yield (P > 0.05). Although Hin6I polymorphism can not be used as a molecular marker for production traits in MAS, the present work presents preliminary novel missense mutation which extends the spectrum of genetic variations of goat PROP1 gene and may benefit for considering its association with other biophysical and biochemical indexes.

GH secretagogue receptor (ghrelin receptor, GHSR) is known to be involved in the control of GH release by mediating the strong stimulatory effect of the endogenous ligand, ghrelin, on GH secretion. Associations between the GHSR gene polymorphism and the growth traits were revealed in Nanyang cattle. The mutations at nt456(G > A) and nt667(C > T) were complete linkage and located in exon 1 of the coding region of the GHSR gene. Least squares analysis revealed a significant statistical effect (P < 0.05) of the GHSR gene different genotypes on body weight and average daily gain at 6 months of age in Nanyang cattle. Individuals with GHSR-MM genotype showed higher body weight and average daily gain than individuals with GHSR-MN genotype.

ACRP30 gene was located nearby the QTL affecting the marbling, ribeye muscle area and fat thickness on the BAT1 in Angus. In this study, a 5bp deletion mutation within the bovine ACRP30 gene was firstly detected and confirmed in 991 cattle by PCR-SSCP, DNA sequencing and direct PCR amplification. The deletion mutation was appeared in Qinchuan, Nanyang, Jiaxian and Hasake, but was not found in Jinnan, Chinese Holsteins and Angus. The association of the deletion polymorphism with growth traits (including birth weight, body weight, average daily gain and body sizes in different growth periods (6/12/18/24 month-old)) was analyzed in 224 Nanyang cattle. No signification association of the deletion polymorphism with growth traits were observed (P > 0.05). The deletion was located in the promoter region and it resulted in a new putative CCAAT/enhancer binding protein-beta response element (C/EBP-RE).