2024-03-28T13:42:42Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1106452017-10-19T15:42:17Zcom_10261_86com_10261_1col_10261_339
The comparative study of five sex-determining proteins across insects unveils high rates of evolution at basal components of the sex determination cascade
Eirín-López, José María
Sánchez, Lucas
Evolution
Development
Sex-specific genes
Insects
Evolutionary rates
29 p.-4 fig.-1 tab. supl.
In insects, the sex determination cascade is composed of genes that interact with each
other in a strict hierarchical manner, constituting a co-adapted gene complex built in
reverse order from bottom to top. Accordingly, ancient elements at the bottom are expected to remain conserved ensuring the correct functionality of the cascade. In the
present work we have studied the levels of variation displayed by five key components of
the sex determination cascade across 59 insect species, including Sex-lethal,
transformer, transformer-2, fruitless, doublesex and sister-of-Sex-lethal (a paralog of Sxl encompassing sex-independent functions). Surprisingly, our results reveal that basal components of the cascade (doublesex, fruitless) seem to evolve more rapidly than previously suspected. Indeed, in the case of Drosophila, these proteins evolve more rapidly than the master regulator Sex-lethal. These results agree with the notion
suggesting that genes involved in early aspects of development will be more constrained due to the large deleterious pleiotropic effects of mutations, resulting in increased levels of purifying selection at top positions of the cascade. The analyses of the selective episodes involved in the recruitment of Sxl into sex determining functions in Drosophila further support this idea, suggesting the presence of bursts of adaptive selection in thecommon ancestor of drosophilids, followed by purifying selection preserving the master regulatory role of this protein. Altogether, this work underscores the importance of the position of sex determining genes in the cascade, constituting a major constraint shaping
the molecular evolution of the insect sex determination pathway.
2015-02-13T11:52:10Z
2015-02-13T11:52:10Z
2015-01
artículo
Dev Genes Evol. 2015 Jan;225(1):23-30
0949-944X
http://hdl.handle.net/10261/110645
10.1007/s00427-015-0491-6
1432-041X
eng
Postprint
http://dx.doi.org/
Sí
openAccess
Springer