HSPA2 is a member of the HSP70 family of heat-shock proteins that serve as molecular chaperones. Researchers discovered that HSPA2 protein is expressed in spermatogenesis during the meiotic phase. Spermatogenic cells lacking the HSPA2 protein arrest in mid-meiosis and undergo apoptosis. HSPA2 is present in the synaptonemal complex of wild-type mice and the chromosomes fail to separate in HSPA2-deficient mice (previously known as Hsp70-2-/- mice), suggesting that HSPA2 is required for the chromosomal events of meiosis such as synapsis, crossing over, or recombination.

Researchers at NIEHS developed a knockout strain of mice in which the heat shock protein gene (Hspa2) is disrupted. This mouse model is useful in studying the process of spermatogenesis and the influence of various environmental toxins or drugs on sperm production and male infertility.