Identification And Functional Analysis Of MRNA And LncRNA Related To Tail Fat Deposition In Sheep

Sheep have evolved a distinctive tail type through adaptive evolution over time,with80% of sheep being fat-tailed.However,due to changes in feeding practices and the development of China’s livestock industry,the fat-tailed trait is no longer suitable for current production needs.Excessive tail fat deposition not only affects meat quality and reproductive performance,but also reduces economic efficiency,thus making the improvement of fat-tailed sheep with thin tails a pressing problem in sheep breeding.Tail fat deposition is a very complex biological process that is influenced by a variety of factors.Previous studies have shown that m RNA,lnc RNA and mi RNA molecules play an important role in tail fat formation and metabolism in sheep.However,studies on the molecular regulatory mechanisms of tail fat deposition in sheep are still inadequate.To address this gap,we selected three Altai sheep with high tail-fat content and three Tibetan sheep with low tail-fat content at approximately one year old for our study to explore the expression characteristics and molecular mechanisms of m RNA,lnc RNA,and mi RNA molecules in tail adipose tissues using transcriptome sequencing technology,bioinformatics analysis,and real-time fluorescence quantitative PCR(RT-q PCR).We also predicted the important lnc RNA-mi RNA-m RNA networks that may regulate tail fat deposition in sheep by combining the key mi RNAs obtained in the previous study.The main research findings are as follows:1.The m RNA-Seq results showed that a total of 512 million Clean Reads were obtained from the tail adipose tissue of Altai and Tibetan sheep,of which 257 million were obtained from Altai sheep and 255 million from Tibetan sheep,and the sample genome matching rate was above 88% in both samples.A total of 679 differentially expressed m RNAs(422 up-regulated and 257 down-regulated)were screened in the tail adipose tissue transcripts of two different tail types of sheep.The functions of differentially expressed m RNAs were mainly enriched in GO entries such as Growth and development,Energy metabolism,and Cell proliferation and Cell apoptosis,and in KEGG signaling pathways such as Cytokine-cytokine receptor interactions,HIF-1,and Regulation of lipolysis in adipocytes.Key genes that may be associated with tail fat deposition in sheep were identified as IGF2,PCNA,PPARγ,FABP7,and CPT1 B.2.The results of lnc RNA-Seq analysis revealed the identification of 740 potential lnc RNAs in two different tail types of sheep tail lipids,and GO and KEGG analysis of their Cis-and Trans-acting target genes revealed that their functions were mainly enriched in biological processes such as Biosynthesis,Catabolism,Lipid transport,and Transcription-translation,Lipid anabolism,Cell motility and Amino acid metabolism pathways.A total of 73 differentially expressed lnc RNAs were screened in two different tail-type sheep tail adipose tissue lipid transcripts,of which 26 were up-regulated and 47 were down-regulated.Functional analysis of GO and KEGG indicated that the main target genes of Cis and Trans actions of differentially expressed lnc RNAs were enriched in biological processes such as oxidative phosphorylation,glycogenesis,translation,and signaling pathways such as B-cell receptors,VEGF,TGF-beta,and Wnt and other signaling pathways.LOC105603197,MSTRG.13896.1,MSTRG.12365.1,and LOC105603996 were found to possibly play important roles in sheep tail fat deposition.3.The expression of oar-mi R-21 was significantly up-regulated and that of oar-mi R-106 a was significantly down-regulated(P<0.05)in the tail adipose tissue of fat-rumped Altai sheep.Target gene prediction was performed for both,and GO and KEGG analysis of the target genes revealed that they were mainly enriched in biological processes and signaling pathways such as Intracellular signaling,ATP binding,MAPK signaling pathway,Phosphatidylinositol signaling system,and PI3K-Akt signaling pathway.4.In this study,10 lnc RNA-mi RNA-m RNA interaction networks that may potentially regulate tail fat deposition in sheep were constructed based on the screened differentially expressed m RNAs,lnc RNAs and two key mi RNAs.To summarize,this study explores the regulatory mechanisms of tail fat deposition in sheep by analyzing m RNA and lnc RNA molecules,as well as ce RNA regulatory networks that may play important regulatory roles in the process of tail fat deposition in sheep.The findings lay a foundation for further research on this topic.