Project description:Deep sequencing of mRNA from 6 organs of yak (Bos grunniens) Analysis of ploy(A)+ RNA of brain,heart,liver,lung,spleen, and stomach of yak (Bos grunniens)
Project description:Purpose: The goal of this study was to reveal epigenetic differences in the microRNA transcriptomes of two organs (heart and lung) between yak and cattle. Methods: Three unrelated 2-year old adult females for both of yaks and cattle (Luxi Huang cattle) were used in this study. Two of significant hypoxia-responsive tissues (heart and lung) were rapidly collected from each carcass, washed three times with physiological saline, immediately frozen in liquid nitrogen. All frozen samples were stored at –80 °C until RNA extraction.The total RNA were extracted with Trizol (Ambion, USA). NanoDrop ND-2000 spectrophotometer (Nano Drop, DE, USA) and Bioanalyzer 2100 (Agilent Technologies, Santa Clara, CA, USA) were used to monitor the concentration and integrity of RNA, respectively. In brief, several successive steps consist the Illumina sequencing. The small RNA with length of 14-40 nt were first purified by polyacrylamide gel electrophoresis (PAGE), and then specific adapters were ligated to the purified small RNA. The ligated RNA were reverse transcribed to cDNA libraries. Finally, each library were sequenced on Genome Analyzer. Results: We identified 808 widely-expressed conserved and 697 species-specific novel miRNAs in two species. In addition, although two organs showed similar high expression miRNAs, larger differentiation was present in lung than heart between two species. In addition, miRNAs with significantly differentiated patterns of expression in two organs exhibited obvious co-operation effect in high altitude adaptation in form of miRNA family and cluster. Functional analysis revealed that a large amount of differentially expressed miRNAs were enriched in hypoxia-related pathways, such as VEGF signaling pathway, HIF-1α signaling pathway, insulin signaling pathway, DNA damage response, apoptosis, fatty acid metabolism and glucose metabolism. These results suggested the diverse degrees of epigenetic variation in different tissues between yak and cattle, and revealed extensive roles of miRNAs in high altitude adaptation. Conclusions: In this study, we illustrated the differences in the microRNA transcriptomes level for heart and lung between yak and cattle, and suggested extensive roles of miRNAs in high altitude adaptation. The work performed here will provide a typical demonstration for future deciphering the mechanism of high altitude adaptation
Project description:The Gayal (Bos frontalis) is a rare semi-domesticated cattle in China. Gayal has typical beef body shape and good meat production performance. Compared with other cattle species, it has the characteristics of tender meat and extremely low fat content. To explore the underlying mechanism responsible for the differences of meat quality between different breeds, the longissimus dorsi muscle (LM) from Gayal and Banna cattle (Bos taurus) were investigated using transcriptome analysis. The gene expression profiling identified 638 differentially expressed genes (DEGs) between LM muscles from Gayal and Banna cattle. Gene Ontology (GO) enrichment of biological functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the gene products were mainly involved in the PPAR signaling pathway, lipid metabolism and amino acid metabolism pathway. Protein-protein interaction(PPI) network analysis showed APOB, CYP7A1, THBS2, ITGAV, IGFBP1 and IGF2R may have great impact on meat quality characteristics of Gayal. Moreover, three transcription factors, FOXA2, NEUROG2, and RUNX1, which may affect meat quality by regulating the expression of genes related to muscle growth and development have also been found. In summary, our research reveals the molecular mechanisms that cause Gayal meat quality characteristics. It will contribute to improving meat quality of cattle through molecular breeding.
Project description:BACKGROUND:Methane emissions by methanogen from livestock ruminants have significantly contributed to the agricultural greenhouse gas effect. It is worthwhile to compare methanogen from "energy-saving" animal (yak) and normal animal (cattle) in order to investigate the link between methanogen structure and low methane production. RESULTS:Diversity of methanogens from the yak and cattle rumen was investigated by analysis of 16S rRNA gene sequences from rumen digesta samples from four yaks (209 clones) and four cattle (205 clones) from the Qinghai-Tibetan Plateau area (QTP). Overall, a total of 414 clones (i.e. sequences) were examined and assigned to 95 operational taxonomic units (OTUs) using MOTHUR, based upon a 98% species-level identity criterion. Forty-six OTUs were unique to the yak clone library and 34 OTUs were unique to the cattle clone library, while 15 OTUs were found in both libraries. Of the 95 OTUs, 93 putative new species were identified. Sequences belonging to the Thermoplasmatales-affiliated Linage C (TALC) were found to dominate in both libraries, accounting for 80.9% and 62.9% of the sequences from the yak and cattle clone libraries, respectively. Sequences belonging to the Methanobacteriales represented the second largest clade in both libraries. However, Methanobrevibacter wolinii (QTPC 110) was only found in the cattle library. The number of clones from the order Methanomicrobiales was greater in cattle than in the yak clone library. Although the Shannon index value indicated similar diversity between the two libraries, the Libshuff analysis indicated that the methanogen community structure of the yak was significantly different than those from cattle. CONCLUSION:This study revealed for the first time the molecular diversity of methanogen community in yaks and cattle in Qinghai-Tibetan Plateau area in China. From the analysis, we conclude that yaks have a unique rumen microbial ecosystem that is significantly different from that of cattle, this may also help to explain why yak produce less methane than cattle.