Gpat2, glycerol-3-phosphate acyltransferase 2, is a mitochondrial outer membrane protein. It is involved in the generation of lysophosphatidic acid (LPA) and is a key enzyme in arachidonic acid (AA) metabolism [2,4]. It plays crucial roles in important biological processes such as piRNA biogenesis, transposon silencing, and spermatogenesis. Genetic models, especially gene-knockout mouse models, have been instrumental in studying its functions [1].

In GPAT2-deficient mice, defective piRNA production and subsequent de-silencing of IAP and Line-1 retrotransposons were observed in fetal testes. Also, apoptosis of pachytene spermatocytes and spermatogonia at the neonatal stage occurred, indicating that GPAT2 is critical for preventing apoptosis in spermatogonia [1]. In human studies, 39 infertile men carrying biallelic variants in GPAT2, among other piRNA pathway genes, showed impaired piRNA biogenesis, transposon de-silencing, and spermatogenic failure [3]. In breast cancer cell lines, GPAT2 silencing led to AA-induced apoptotic cell death, showing its role in preventing apoptosis in cancer cells [4].

In conclusion, GPAT2 is essential for normal spermatogenesis and piRNA-related processes in the germline. Its deficiency in mouse models leads to spermatogenic defects and apoptosis. In human male infertility, mutations in GPAT2 can disrupt the piRNA pathway. In cancer, GPAT2 may contribute to tumorigenesis by inhibiting apoptosis. Research on GPAT2 using KO mouse models provides insights into spermatogenesis and male infertility as well as cancer development mechanisms.