Lactate dehydrogenase a-like 6B is not essential for spermatogenesis and male fertility in mice

Lactate is recognized as a principal energy substrate for male germ cells. Lactate dehydrogenases (LDHs) catalyze the reversible conversion between pyruvate and lactate, which are required for male fertility. Among them, lactate dehydrogenase A-like 6B (Ldhal6b) has been identified as a testis-specific LDH gene. However, its precise roles in spermatogenesis remain to be elucidated. In this study, we used a Ldhal6b knockout mouse model to assess its impact on spermatogenesis. Our findings reveal that Ldhal6b knockout mice exhibit normal development and no significant alterations in male fertility. Further, LDHAL6B is localized to mitochondria and closely associated with germ granules. Nevertheless, its depletion does not result in significant abnormalities in mitochondria, germ granules or impact piRNA biogenesis. We also observed alterations in the abundance of proteins related to mitochondrial metabolism in sperm from Ldhal6b knockout mice, align with its specific localization to mitochondria. Overall, our results indicate that Ldhal6b is dispensable for both mouse development and spermatogenesis under normal laboratory conditions.