Sex chromosomes in Trichonephila senegalensis

Sex dimorphism reaches extremes in the spider species In Trichonephila senegalensis. However, the underlying genetic basis still remain poorly understood as extensive genomic resources for spiders are still limited. In this study, a highly representative transcriptome has been as assembled, which served as the basis for the identification of X-linked and autosomal regions through segregation analyses. Both types of regions demonstrate a female bias in their gene expression, while in addition it could be shown that mechanisms for dosage compensation of X chromosomal genes in males are at play. It could be shown that X chromosomes evolve at a faster rate than autosomes, confirming the Faster X hypothesis in T. senegalensis. Further, X-linkage of the identified regions could be verified in vitro, providing the basis for a sex diagnosis method applicable at all stages of development.