Androgen receptor mutation affects testes organization in an African cichlid A. burtoni

Androgen receptors (AR) are a ligand-dependent transcription factor that modulate the expression of androgen target genes. Androgens are hormones that bind to ARs and are essential to reproductive development and fertility. Past research illustrates that mutations in AR lead to small testes, disorganization of seminiferous tubules, and delay the process of spermatogenesis. The objective of this research is to investigate how the mutation of both ARalpha and ARbeta affect the organization of the testes and the process of spermatogenesis in the African cichlid fish, Astatotilapia burtoni. Firstly, we used a cryostat to section the testes at a thickness of 10 microns. Once the slides were dry, we conducted a Hematoxylin and Eosin (H&E) stain on the tissue in order to differentiate cell types. Photomicrographs were then taken of multiple sections in each testis and a grid of randomly generated points was overlaid. The cell type underneath 50 points was counted on a random section of the tissue; cell types of spermatogonia, spermatids, spermatozoa, and interstitial tissue were quantified as a measure of spermatogenesis. The homozygous ARalpha;ARbeta mutants appear to have numerous holes relative to the wild type (WT) testes and this will be quantified in the future. Furthermore, quantifications of cell types will be analyzed between WT and mutants in the future as well as the fertility of the sperm of the mutants.