Whole Transcriptome Sequencing and Differential Analysis of Testes in Pre- and Post-sexual Maturity Bactrian Camels (Camelus bactrianus)

Testicular development is a conserved and tightly regulated biological process. Understanding the molecular mechanisms underlying testicular development in Bactrian camels will benefit the advancement of related industries. In this study, transcriptomic analyses were conducted on testicular tissues of Junggar Bactrian camels at 3 years of age (pre-sexual maturity, Group C) and 5 years of age (post-sexual maturity, Group E). A total of 7,031 differentially expressed (DE) mRNAs were identified between the two groups, of which 4,169 were upregulated and 2,871 downregulated. Additionally, 291 differentially expressed long non-coding RNAs (DElncRNAs) were detected, including 207 upregulated and 84 downregulated transcripts, and 142 differentially expressed microRNAs (DEmiRNAs) were identified, of which 108 were upregulated and 34 were downregulated. Among the identified DERNAs, 291 DElncRNAs and 87 DEmiRNAs were previously unreported, providing valuable candidates for future investigations into the molecular mechanisms of testicular development and spermatogenesis in male Bactrian camels. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed that commonly differentially expressed genes during testicular development are mainly involved in signal transduction (biological process, BP), synaptonemal complex formation (cellular component, CC), calcium ion binding (molecular function, MF), as well as signaling pathways such as insulin, MAPK, and PI3K-Akt. This study analyzed the differential expression of mRNAs, lncRNAs, and miRNAs before and after sexual maturity in Junggar Bactrian camels, providing a valuable reference for future research on testicular development and spermatogenesis in this species.