Gene expression profile analysis of subregions of the adult female reproductive tract in the brown anole, Anolis sagrei.

The morphological diversity and functional role of the organs of the female reproductive system across tetrapods (limbed vertebrates) are relatively poorly understood. Though some features are morphologically similar, species-specific modification makes comparisons between species and inference about evolutionary origins challenging. In combination with the study of morphological changes, studying differences in gene expression in the adult reproductive system in diverse species can clarify the function of each organ. Here, we use the brown anole, Anolis sagrei, to study gene expression differences within the reproductive tract of the adult female. We generated gene expression profiles of four biological replicates of the three regions of the female reproductive tract, the infundibulum, glandular uterus, and nonglandular uterus by RNA-sequencing. We aligned read to the recently published Anolis sagrei genome and identified significantly differentially expressed genes between the regions using DEseq2. Each organ expressed approximately 14600 genes and comparison of gene expression profiles between organs revealed between 367-883 differentially expressed genes. We identify shared and region-specific transcriptional signatures for the three regions and compare gene expression in the brown anole reproductive tract to known gene expression patterns in other tetrapods. We find that genes in the Hox cluster have an anterior-posterior, colinear expression pattern as has been described in mammals. We also define a secretome for the glandular uterus. These data provide fundamental information for functional studies of the reproductive tract organs in the brown anole as well as an important phylogenetic anchor for comparative study of the evolution of the female reproductive tract.