PLIN1 deficiency affects testicular gene expression at the meiotic stage in the first wave of spermatogenesis.

PLIN1, a lipid droplet associated protein, has been implicated in playing a key role in the regulation of lipolysis and lipid storage in adipocytes. PLIN1 is found to be highly expressed in Leydig cells of testis, suggesting a potential role in steroidogenesis and spermatogenesis. In this study, we showed that PLIN1 was expressed in testis and that its mRNA levels declined significantly with development. To investigate the role of PLIN1, we take advantage of PLIN1-null mice. We found that the number of seminiferous tubules containing round spermatids was significantly increased at P21 (postnatal day 21). Furthermore, microarray analysis showed that there were 538 differentially expressed genes between PLIN1-null and wild-type mice at P21. The up-regulated genes in knockout mice were enriched in spermatogenesis by Gene Ontology classification. Among them, Prm1 and Wbp2nl are important for spermatogenesis which were confirmed by real-time PCR. Unexpectedly, the levels of serum testosterone and serum 17β-estradiol as well as steroidogenic genes are not altered in the PLIN1-null mice. Compared to the wild-type mice, no significant difference of fertility was found in the PLIN1-null mice. Therefore, these findings indicated that PLIN1 disruption leads to the increase of round spermatid-containing seminiferous tubules at the meiotic stage of the first wave of spermatogenesis through regulating spermatogenic related genes.