RT-qPCR expression analysis of texim genes in adult tissues of Xiphophorus maculatus population Rio Usumacinta. All qPCR results were normalized against the ribosomal protein L7 housekeeping gene rpl7, the value 1 was assigned to the tissue/organ with the highest level of expression. M: males (in blue); F: females (in red). All texim genes are strongly expressed in testis, with teximYb and texim2 being almost exclusively expressed in the male gonad. Texim1 is also strongly expressed in gills, and texim4 in brain.