Mechanisms of Variation in Abdominal Adipose Color Among Male Kazakh Horses Through Non-Coding RNA Sequencing

The Kazakh horse is a highly valuable indigenous Chinese breed known for its use in both milk and meat production. However, the mechanisms underlying color variation in the abdominal adipose tissue of this breed remain poorly understood. In this study, the sequencing of non-coding RNAs (ncRNAs) was conducted on abdominal adipose tissue of different colors from Kazakh horses, with the aim of investigating the molecular mechanisms responsible for this variation. A total of 205 differentially expressed long non-coding RNAs (DELncRNAs) including ENSECAG00000003836, ENSECAG00000017858, and ENSECAG00000035167; 52 differentially expressed microRNAs (DEmiRNAs) including miR-200-y and eca-miR-9a; and 559 differentially expressed circular RNAs (DEcircRNAs) including ZNF226 and ITPKC, were identified between Group W and Group Y. GO annotation and KEGG enrichment analyses of the DEGs revealed that these genes were primarily involved in biological processes such as chemical homeostasis (biological process, BP), intracellular components (cellular component, CC), and iron-sulfur cluster binding (molecular function, MF) as well as in metabolic pathways related to lipid biosynthesis and metabolism including vitamin B6 metabolism, tryptophan metabolism, and glycerolipid metabolism. The sequencing accuracy was further validated using reverse transcription quantitative PCR (RT-qPCR). This study identified key DEGs and signaling pathways associated with the color variation in adipose tissue of Kazakh horses and sheds light on the regulatory genes and biological processes involved. These findings provide a theoretical basis and research foundation for future studies on color variations in the adipose tissue of equine species.