An Integrated Analysis of Lactation-Related miRNA and mRNA Expression Profiles in Donkey Mammary Glands

Abstract

Donkey milk is consumed by humans for its nutritional and therapeutic properties. MicroRNAs (miRNAs) and messenger RNAs (mRNAs) have been implicated in the regulation of milk component synthesis and mammary gland development. However, the regulatory profile of the miRNAs and mRNAs involved in lactation in donkeys is unclear. We performed mRNA-seq and miRNA-seq and constructed coexpression regulatory networks for the mammary glands during the lactating and nonlactating period of jennies. We identified 3144 differentially expressed (DE) mRNAs (987 upregulated mRNAs and 2157 downregulated mRNAs) and 293 DE miRNAs (231 upregulated miRNAs and 62 downregulated miRNAs) in the lactating group compared to the nonlactating group. The DE miRNA target mRNA were significantly associated with pathways related to RNA polymerase, glycosphingolipid biosynthesis, mRNA surveillance, ribosome biogenesis in eukaryotes, glycerophospholipid metabolism, Ras signaling, and the fly hippo signaling pathway. The mRNA–miRNA coregulation analysis showed that novel-m0032-3p, miR-195, miR-26-5p, miR-23-3p, miR-674-3p, and miR-874-3p are key miRNAs that target mRNAs involved in immunity and milk lipid, protein, and vitamin metabolism in the jenny mammary gland. Our results improve the current knowledge of the molecular mechanisms regulating bioactive milk component metabolism in the mammary glands and could be used to improve milk production in donkeys.

Exploring Genetic Markers: Mitochondrial DNA and Genomic Screening for Biodiversity and Production Traits in Donkeys

“…The study proposes that these genetic variations could serve as valuable markers for selective breeding programs in donkeys [98]. Furthermore, by conducting a transcriptomic analysis, Fei et al [99] reported several genes (CSN1S2, LEPR, LTF; CSN2, CSN1S1, CSN3, LALBA, SPP1, MGP, TGFβ1, FASN, SCD, ACACA, PPARG, INS, IGF1, GH, PRL) and pathways (lactose biosynthesis, fatty acid biosynthesis, insulin signaling pathway, prolactin signaling pathway, PI3K-Akt signaling pathway, MAPK signaling pathway, TGF-beta signaling pathway, ECM-receptor interaction) that were associated with milk production phenotypic traits in donkeys [99]. The existing data published on donkey research showed that there is still very limited information are available in this area.…”