Morphological alterations in mouse testes following siRNA-mediated Sry gene silencing.

The Sry gene on the Y chromosome is pivotal for male sex determination in mammalian embryos. Beyond embryogenesis, Sry transcripts are also found in adult tissues, including testes, leading to speculation about its role in adult testicular physiology. However, conclusive evidence about its function in these contexts is limited. Herein, we employed siRNA technology associated with carbon nanotubes to investigate the impact of Sry RNA silencing in adult male mice. The siRNA was administered via tail vein injection in Balb-C mice. Three days post-injection, the testis and epididymis were collected for analysis. We utilized a range of techniques, including Laser Doppler analysis, testicular morphometry, immunohistochemistry, TUNEL assay, and qPCR, to assess the effects of RNA silencing. Our findings revealed several significant changes following siRNA treatment. In severely affected animals, we observed a Sertoli cell-only phenotype, which indicates substantial germ cell loss. In animals with mild effects, we found several testicular alterations, including changes in testicular blood flow, predominant sloughing of spermatids from the seminiferous epithelium, increased germ cell apoptosis, alterations in the protein pattern of the Sertoli cell barrier and thickening of the tunica propria. Although we observed a hypertrophy of Leydig cells, testosterone levels remained unaltered. These results suggest that the Sry RNA is critical in maintaining testicular architecture and regulating germ cell dynamics in adult mice. Our study provides new insights into the significance of the Sry gene/RNA in aspects of testicular physiology beyond embryonic sexual differentiation, highlighting its potential impact on germ cell development.