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In the current study, a total of six 5 year old healthy bulls reared in heat stress zone were used and semen from these bulls was collected by artificial vagina and undergoes for semen quality analysis. Results of semen quality parameters showed that the average semen volume and sperm density of Simmental bulls were 9.3mL and 1.23 × 109mL, and sperm acrosome integrity rate were lower as compared to Xiangxi cattle bulls. The transcriptome analysis revealed a 36.8Gb clean data and the obtained clean data of each sample was reached 5.84Gb. The transcriptome analysis further revealed that the percentage of q30 base was 91.19% or above. Based on the comparison results, 4,890 new genes were found, including 2,451 functional annotations. Go analysis explored that GO annotation system included 3 main sections that were biological processes, molecular functions and cellular components, respectively. In conclusion, results showed that the average semen volume and sperm density of Simmental bulls was higher and sperm motility and sperm acrosome integrity rate was lower as compared to Xiangxi cattle bulls. This study has developed a transcriptomic profile of spermatozoa of Xiangxi cattle and Simmental cattle bulls and reported Xiangxi cattle and Simmental cattle bull’s spermatozoa change the gene expression involved in various biological process. This study could provide the experimental basis of poor fertility in Xiangxi cattle bulls and provide possible fertility biomarkers. [ABSTRACT FROM AUTHOR]

Understanding the genetic diversity in Xiangxi cattle may facilitate our efforts toward further breeding programs. Here we compared 23 Xiangxi cattle with 78 published genomes of 6 worldwide representative breeds to characterize the genomic variations of Xiangxi cattle. Based on clustering models in population structure analysis, we displayed that Xiangxi cattle had a mutual genome ancestor with Chinese indicine, Indian indicine, and East Asian taurine. Population genetic diversity was analyzed by four methods (nucleotide diversity, inbreeding coefficient, linkage disequilibrium decay and runs of homozygosity), and we found that Xiangxi cattle had higher genomic diversity and weaker artificial selection than commercial breed cattle. Using four testing methods (θπ, CLR, FST, and XP-EHH), we explored positive selection regions harboring genes in Xiangxi cattle, which were related to reproduction, growth, meat quality, heat tolerance, and immune response. Our findings revealed the extent of sequence variation in Xiangxi cattle at the genome-wide level. All of our fruitful results can bring about a valuable genomic resource for genetic studies and breed protection in the future. [ABSTRACT FROM AUTHOR]

The molecular mechanisms which regulate the developmental processes of ovary and result in increased reproductive efficiency of beef cattle need further investigations for optimum beef production. The study was designed to screen the signaling pathways and to investigate the genes related to development of ovarian tissues of Xiangxi cattle at different age (6, 18 and 30 months) by transcriptome sequencing and bioinformatics analysis. Illumina II high-throughput sequencing technology was used to seq transcriptomes of nine Xiangxi cattles ovarian tissues at different ages. The total number of ovarian genes assembled were compared with reference genome sequences, differentially expressed gene analysis, KEGG and GO enrichment analysis and finally the candidate genes screening were performed. The results showed that about 68.51 Gb clean data was obtained and clean data of each sample reached to the 6.10 Gb. A total of 26243 expressed genes were screened, of which 4866 genes were new and have not been annotated in any database. A total of 594 differentially expressed genes were annotated between 6 and 30-months groups. Similarly, a total of 141 differentially expressed genes were annotated between 18and 30-mths groups. Among these, the members of G-protein coupled receptors family like follicle-stimulating hormone receptor (FSHR) and Insulin-like 3 peptides (INSL3) participate in signaling pathways. These results suggest that FSHR and INSL3 may be related to the reproductive development and reproductive performance of ovarian tissues in Xiangxi cattle and play an important role. [ABSTRACT FROM AUTHOR]

The regulatory mechanisms controlling the ovary development in the Xiangxi cattle are still largely unknown, yet the growth and development of ovary is a complex process that plays a crucial role in reproduction. In this study, we performed a transcriptome analysis based on the RNA sequencing (RNA-Seq) of Xiangxi cattle and Angus cattle tissue obtained from 8 months of age to identify which genes are differentially expressed and to investigate their temporal expression profiles. The results showed that a total of 165 differential genes were annotated, of which 58 were annotated in the GO database and 73 were annotated in the KEGG database. A total of 12 comparatively concentrated signal pathways were obtained. Among them, the osteoclast differentiation signaling pathway (ko04380) was the most involved in differentially expressed genes. The other signaling pathways were amphetamine addiction, herpes simplex infection, caffeine metabolism, cocaine addiction, pertussis, ECM-receptor interaction, toll-like receptor signaling pathway, and glycosphingolipid biosynthesis - ganglio series. Functional analysis also showed that the differentially expressed genes were involved in various Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. GO annotations indicated that the genes related to biological processes, and molecular events were significantly active. KEGG pathway analysis showed that the osteoclast differentiation signaling pathway in Xiangxi ovary transcriptome data, at the end ECM-receptor interaction pathways. Moreover, several novel pathways, were significantly enriched despite having no evident associations with the reproductive function. Our findings provide a molecular resource for further investigation of the general molecular mechanism of Xiangxi cattle ovary and offer new insights to understand comprehensively the specificity of local cattle breeds reproduction. [ABSTRACT FROM AUTHOR]

Current study was conducted to evaluate the effects of age on production performance and meat quality of Xiangxi cattle. A total of 12 male weaning Xiangxi cattle (similar age and weight) were used in the current experiment. Animals were slaughtered at the age of six, eight and thirty months. Results showed that animals slaughtered at 30 months of age had the highest production performance and carcass traits (p < 0.05). The longissimus dorsi (LD) of the animals slaughtered at 6-month-age had a lower cooking loss and higher water content (p < 0.05). The LD of the animals slaughtered at 30-month-had significantly higher nutrient composition, total essential amino acid (EAA) composition and EAA/total amino acid percentage, C16 and saturated fatty acid (SFA) contents (p < 0.05). Moreover, higher C20, C17:1, monounsaturated FA, C18:3n-3, polyunsaturated FA, total FA contents and unsaturated fatty acid to saturated fatty acid ratio (p < 0.05) was observed in the LD muscle of cattle slaughtered at 18 months of age. Based on results, it is concluded that age significantly influenced the production performance, carcass traits, meat quality, and meat nutrient composition in Xiangxi cattle. [ABSTRACT FROM AUTHOR]

Understanding the genetic diversity in Xiangxi cattle may facilitate our efforts toward further breeding programs. Here we compared 23 Xiangxi cattle with 78 published genomes of 6 worldwide representative breeds to characterize the genomic variations of Xiangxi cattle. Based on clustering models in population structure analysis, we displayed that Xiangxi cattle had a mutual genome ancestor with Chinese indicine, Indian indicine, and East Asian taurine. Population genetic diversity was analyzed by four methods (nucleotide diversity, inbreeding coefficient, linkage disequilibrium decay and runs of homozygosity), and we found that Xiangxi cattle had higher genomic diversity and weaker artificial selection than commercial breed cattle. Using four testing methods (θπ, CLR, F , and XP-EHH), we explored positive selection regions harboring genes in Xiangxi cattle, which were related to reproduction, growth, meat quality, heat tolerance, and immune response. Our findings revealed the extent of sequence variation in Xiangxi cattle at the genome-wide level. All of our fruitful results can bring about a valuable genomic resource for genetic studies and breed protection in the future.ST , and XP-EHH), we explored positive selection regions harboring genes in Xiangxi cattle, which were related to reproduction, growth, meat quality, heat tolerance, and immune response. Our findings revealed the extent of sequence variation in Xiangxi cattle at the genome-wide level. All of our fruitful results can bring about a valuable genomic resource for genetic studies and breed protection in the future., Competing Interests: Authors YL and TL is employed by Hunan De Nong Animal Husbandry Group Co. Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Luo, Li, Xiao, Sun, Xiang, Chen, Lei, Lei, Long, Long, Suolang and Yi.)