The azoospermia factor (AZF) region on the Y chromosome consists of genes required for spermatogenesis. Among the three subregions. the AZFc subregion located at the distal portion of AZF is the driver for genetic variation in Y chromosome. The candidate gene of AZFc is known as deleted in azoospermia gene. https://excellentphoto.shop/product-category/underwater-protection/