Transcriptome and small RNA landscapes of testis and epididymis across reproductive seasons in the tree shrew

Male tree shrews (Tupaia belangeri), as species closely related to primates, exhibit distinct seasonal reproductive characteristics: during the non-reproductive season, testis weight is significantly reduced, spermatogenesis is markedly restricted, showing typical cyclical regeneration of reproductive organs and spermatogenesis. However, the key genes driving this process and their regulatory mechanisms remain poorly understood. In this study, we used the Illumina platform to perform RNA-seq and sRNA-seq on testis (TESTIS), caput epididymis (CAPUT), and cauda epididymis (CAUDA) tissues collected from tree shrews during the reproductive (R) and non-reproductive (NR) seasons, constructing high-quality transcriptome and small RNA datasets. A total of 21,299 expressed genes were identified, and six core candidate genes highly associated with seasonal reproduction were screened using weighted gene co-expression network analysis (WGCNA). Additionally, 263 novel miRNAs, 59,590 piRNAs, and 139 piRNA clusters were identified, and a multi-level regulatory network integrating miRNAs, key genes, and piRNAs was further constructed. This study provides the first systematic transcriptome and small RNA resource for analyzing seasonal reproductive regulation in male tree shrews, offering new molecular evidence and a reference framework for elucidating the seasonal regulatory mechanisms of testicular development and spermatogenesis in mammals.