This study is to investigate the difference in bovine fecal microbiota between grazing and feedlot Angus cattle. Fecal samples were collected from six Angus cattle grazed on grassland and six Angus cattle fed on a feedlot. The fecal bacterial community was analyzed by high-throughput sequencing of 16S rRNA gene. Sequencing of the V3–V4 region totally produced 1,113,170 effective tages that were computationally clustered into 775 operational taxonomic units (OTUs). These 775 OTUs were taxonomically assigned to bacterial 12 phyla, 19 classes, 25 orders, 54 families, 141 genera, and 145 species. The dominant phyla were Firmicutes and Bacteroidetes. There was similar species richness between grazing and feedlot Angus beef, while higher species diversity was observed in feedlot Angus beef. The relative abundance of Firmicutes, Cyanobacteria, Elusimicrobia and Patescibacteria was significantly different between grazing and feedlot Angus beef (p < 0.05). At a genus level, five microbiotas were significantly different between the two groups and all belonged to the Firmicutes phylum. These significant differences in microbiota composition between grazing and feedlot Angus beef may have an impact on the meat quality of Angus beef.

Cattle-yak is an excellent hybrid of cattle and yak; they are characterized by better meat quality and stronger adaptability of harsh environments than their parents. However, male sterility of cattle-yak lay restraints on the transmission of heterosis. In this study, next generation sequence technology was performed to profile the testicular tissues transcriptome (lncRNA and mRNA) of cattle, yak, and cattle-yak. We analyzed the features and functions of significant differentially expressed genes among the three breeds. There are 9 DE lncRNAs and 46 DE mRNAs with comparisons of cattle, yak, and cattle-yak. Among them, the upregulated targeting genes, such as IGF1 and VGLL3 of cattle-yak lncRNA, may be related to the derangement of spermatocyte maturation and cell proliferation. Similarly, we found that the LDOC1 gene, which is related to the process of cellular apoptosis, is overexpressed in cattle-yak. GO enrichment analysis demonstrated that the cattle-yak is lacking the regulation of fertilization (GO: 0009566), spermatogenesis process (GO: 0007283), male gamete generation process (GO: 0048232), sexual reproduction (GO: 0019953), and multi-organism reproductive process (GO: 0044703), such processes may play important and positive roles in spermatogenesis and fertilization. Furthermore, the KEGG enrichment analysis showed that the upregulated DEGs of cattle-yak most enriched in Apoptosis (ko04210) and Hippo signaling pathway (ko04390), may lead to excessively dead of cell and inhibit cell growth, resulting in obstruction of meiosis and spermatogenesis processes. This study will enable us to deeper understand the mechanism of male cattle-yak infertility.

Pigmentation genes such as MC1R, MITF, TYR, TYRP1, and MLPH play a major role in rabbit coat color. To understand the genotypic profile underlying coat color in indigenous Chinese rabbit breeds, portions of the above-mentioned genes were amplified and variations in them were analyzed by DNA sequencing. Based on the analysis of 24 Tianfu black rabbits, 24 Sichuan white rabbits, 24 Sichuan gray rabbits, and 24 Fujian yellow rabbits, two indels in MC1R, three SNPs in MITF, five SNPs (single nucleotide polymorphisms) in TYR, one SNP in TYRP1, and three SNPs in MLPH were discovered. These variations have low-to-moderate polymorphism, and there are significant differences in their distribution among the different breeds (p < 0.05). These results provide more information regarding the genetic background of these native rabbit breeds and reveal their high-quality genetic resources.

Cattle-yak, the first-generation offspring of cattle and yak, inherited many excellent characteristics from their parents. However, F1 male hybrid infertility restricts the utilization of heterosis greatly. In this study, we first compared the testicular tissue histological characteristics of three cattle, three yaks, and three cattle-yak. Then we explored the miRNA profiles and the target functions of nine samples with RNA-seq technology. We further analyzed the function of DE gene sets of mRNA profiles identified previously with GSEA. Testicular histology indicated that the seminiferous tubules became vacuolated and few active germ cells can be seen. RNA-seq results showed 47 up-regulated and 34 down-regulated, 16 up-regulated and 21 down-regulated miRNAs in cattle and yaks compared with cattle-yak, respectively. From the intersection of DE miRNAs, we identified that bta-miR-7 in cattle-yak is down-regulated. Target prediction indicated that the filtered genes especially MYRFL, FANCA, INSL3, USP9X, and SHF of bta-miR-7 may play crucial roles in the reproductive process. With further network analysis and GSEA, we screened such hub genes and function terms, we also found some DE gene sets that enriched in ATP binding, DNA binding, and reproduction processes. We concluded that bta-miR-7 may play an important role in influencing fecundity. Our study provides new insights for explaining the molecular mechanism of cattle-yak infertility.

BackgroundCattle-yak, the first-generation offspring of cattle and yak, inherited many excellent characteristics from their parents. However, F1 male hybrid infertility restricts the utilization of heterosis greatly. The coding genes can transcript into such mRNAs and further translate into proteins to maintain the activities of organisms. MiRNAs are endogenous small noncoding RNA that silenced their target mRNA expression by high complementary binding sites. In recent years, mRNA and miRNA profiles produced by high-throughput sequencer had interpreted the molecular mechanisms of numerous biological phenomena. However, based on the cattle-yak male sterility, the comprehensive comparison of testicular tissue RNA profiles of cattle, yak and cattle-yak have not been conducted. ResultsTesticular histology indicated that the seminiferous tubules became vacuolated and there are few active germs cells can be seen. With the RNA-seq analysis we finally identified 47 up-regulated miRNAs and 34 down-regulated miRNAs in cattle, 16 up-regulated miRNAs and 21 down-regulated miRNAs in cattle and yaks compared with cattle-yak, respectively. Furthermore, we found that the known miRNA bta-miR-7 was commonly down-regulated in cattle-yak group, revealed the vital role of miR-7 in the regulation of reproductive processes. With the target prediction, the coding genes MYRFL, FANCA, INSL3, USP9X, SHF became the regulated candidates. The network analysis of GO to GO and pathway to pathway annotated such hub terms and genes related to many regulatory functions. We also performed GSE GO and GSE KEGG to display the function of DE gene sets authenticated in our previous study and found that the gene sets most enriched in ATP binding, DNA binding, reproduction process and MAPK signaling pathway, uncovered the relevance between the DE genes and cattle-yak male infertility. ConclusionsWe first obtained the compared miRNAs profiles of testicular tissue samples among cattle, yak and cattle-yak and analyzed the fundamental functions of their target genes. As a complement, GSEA of mRNA profiles identified in our previous study was also be conducted. This study preliminarily revealed some miRNAs related to reproductive processes such as bta-miR-7 and such critical regulatory pathways. Our research is of great significance to explore the molecular mechanism of cattle-yak infertility and look for strategies to resolve this difficult problem.