Identification of key miRNAs regulating fat metabolism based on RNA-seq from fat-tailed sheep and F2 of wild Argali

Ovine LncRSFD1 Mined from RNA-Seq: Identification, Expression Profile, Promotion of Preadipocyte Differentiation, Promoter Activity, and Its Polymorphisms Related to Phenotypic Traits

Tail fat is essential for sheep survival in extreme environments, yet its significance is often overlooked, leading to the decline of fat-tailed breeds. This study identified a novel lncRNA, lncRSFD1 (TCONS_00054953), through transcriptome sequencing, showing differential expression in the tail adipose tissues of Lanzhou Fat-Tailed (LFT) sheep and Tibetan (TS) sheep. Highly expressed in adipose tissues, lncRSFD1 inhibits preadipocyte proliferation and promotes 3T3-L1 differentiation, suggesting its role in regulating fat deposition. Located in both the cytoplasm and nucleus, lncRSFD1 targets the neighboring gene PDE4DIP and may function as a molecular sponge for conserved miRNAs, including oar-miR-30a-3p, oar-miR-329b-5p, and oar-miR-431, which are known to influence fat and muscle-related physiological processes. Moreover, the core promoter of lncRSFD1 (-2607 bp to -1776 bp) harbors four SNPs (g.-2429G>A, g.-2030T>C, g.-2016C>T, g.-2015G>A) significantly associated with growth traits such as body height in Guiqian Semi-Fine Wool (GSFW) sheep. These findings suggest lncRSFD1 plays a key role in fat deposition and growth regulation, offering new insights into the molecular mechanisms of lncRNAs in sheep. It provides a potential target for genetic improvement and molecular breeding to enhance fat deposition and adaptability in sheep breeds.

Genetics of the phenotypic evolution in sheep: a molecular look at diversity-driving genes

BACKGROUND

After domestication, the evolution of phenotypically-varied sheep breeds has generated rich biodiversity. This wide phenotypic variation arises as a result of hidden genomic changes that range from a single nucleotide to several thousands of nucleotides. Thus, it is of interest and significance to reveal and understand the genomic changes underlying the phenotypic variation of sheep breeds in order to drive selection towards economically important traits.

REVIEW

Various traits contribute to the emergence of variation in sheep phenotypic characteristics, including coat color, horns, tail, wool, ears, udder, vertebrae, among others. The genes that determine most of these phenotypic traits have been investigated, which has generated knowledge regarding the genetic determinism of several agriculturally-relevant traits in sheep. In this review, we discuss the genomic knowledge that has emerged in the past few decades regarding the phenotypic traits in sheep, and our ultimate aim is to encourage its practical application in sheep breeding. In addition, in order to expand the current understanding of the sheep genome, we shed light on research gaps that require further investigation.

CONCLUSIONS

Although significant research efforts have been conducted in the past few decades, several aspects of the sheep genome remain unexplored. For the full utilization of the current knowledge of the sheep genome, a wide practical application is still required in order to boost sheep productive performance and contribute to the generation of improved sheep breeds. The accumulated knowledge on the sheep genome will help advance and strengthen sheep breeding programs to face future challenges in the sector, such as climate change, global human population growth, and the increasing demand for products of animal origin.