Molecular Investigations on Angiogenesis and Oxidative Stress in Roe Deer (Capreolus capreolus) Bucks' Testes Throughout the Reproductive Cycle

Animals with seasonal reproductive cycles, as the Roe deer (Capreolus capreolus), have developed mechanisms to synchronize reproduction with the environmental cycle in order to optimize reproductive success through melatonin. Angiogenesis and oxidative stress are key processes in spermatogenesis, contributing to testicular remodeling and recovery after reproductive effort. This study carried out a gene expression analysis on 18 samples of mature male Roe deer testicles, collected during the local hunting season in pre-rut (N = 9) and post-rut (N = 9) periods. A quantitative real-time PCR (qPCR) array targeting 84 genes involved in oxidative stress and 84 in angiogenesis were used, followed by validation through individual qPCR of selected genes and related protein quantification by ELISA assays. Post-rut animals showed upregulation of several antioxidant genes: Peroxiredoxin-4 (PRDX4), Scavenger receptors class A member 3 (SCARA3), Superoxide Dismutase 3 (SOD3). Instead, Leptin (LEP) and Thrombospondin II (THBSII), a known angiogenesis inhibitor, are downregulated. A novel insight is represented by the upregulation of Neuropilin (NRP2) in post-rut period that, given to its posttranscriptional silencing too, needs better investigations. The pleiotropic nature of NRP2, including roles in neurodevelopment, immune modulation, and vascular remodeling, makes this gene an interesting candidate for further study, cause its function in reproductive tissues remains poorly understood.