Glycerol-3-phosphate acyltransferase 2 (GPAT2) is required for mouse spermatogenesis

GARCÍA FABIANI MARIA BELEN; STRINGA, PABLO; CATTANEO, ELIZABETH; PELLON MAISON, MAGALI; HENNING, FLORENCIA; MONTANARO, MAURO ALDO; GONZALEZ BARO, MARIA DEL ROSARIO

Congreso; 51 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2015

Glycerol-3-phosphate acyltransferase 2 (GPAT2) differs from the other GPAT family members (GPAT1, 3, and 4); it is expressed almost exclusively in spermatic cells while the other 3 isoforms are expressed in lipogenic tissues. We have determined that mouse Gpat2 mRNA is expressed transiently in one step of spermatogenesis, the pachytene spermatocytes. To understand its transcriptional regulation, we bisulfite-sequenced the genomic DNA of male germ cells and found a global hypomethylation of Gpat2 promoter at 11 days of age, when meiosis starts, indicating that DNA methylation governs Gpat2 mRNA expression. To further understand the role of GPAT2 in spermatogenesis, we performed an in vivo lentivirus-mediated Gpat2 silencing in mouse testis. Histological and immunohistochemical analysis showed both a strong pre-meiotic arrest and a severe decrease in the number of mature sperm cells. We studied the effect of GPAT2 on male fertility and found that the Gpat2-silenced mice showed a diminished number of births compared to the control mice group. Also, we studied the expression of target genes which are differentially expressed during different phases of the spermatogenesis by qPCR to determine more precisely the step where this process stops when Gpat2 is silenced. These results demonstrate that GPAT2 is important for the normal progress of spermatogenesis in post-natal testis development.