GAPDH and Infertility: A number of mouse strains with KOs of sperm-specific metabolic enzymes (phosphoglycerate Kinase 2, glyceraldehyde 3-phosphate dehydrogenase, and lactate dehydrogenase C) display sperm motility defects which correlate to male-specific infertility (Miki et al., 2004; Odet et al., 2008; Danshina et al., 2010), but in vivo migration has not been studied.