Molecular phylogeny of the ETS gene family

We have constructed a molecular phylogeny of the ETS gene family, By distan ce and parsimony analysis of the ETS conserved domains we show that the fam ily containing so far 29 different genes in vertebrates can be divided into 13 groups of genes namely ETS, ER71, GABP, PEA3, ERG, ERF, ELK, DETS4, ELF , ESE, TEL, YAN, SPI, Since the three dimensional structure of the ETS doma in has revealed a similarity with the winged-helix - turn- helix proteins, we used two of them (CAP and HSF) to root the tree. This allowed us to show that the family can be divided into five subfamilies: ETS, DETS4, ELF, TEL and SPI, The ETS subfamily comprises the ETS, ER71, GABP, PEA3, ERG, ERF a nd the ELK groups which appear more related to each other than to any other ETS family members. The fact that some members of these subfamilies were i dentified in early metazoans such as diploblasts and sponges suggests that the diversification of ETS family genes predates the diversification of met azoans. By the combined analysis of both the ETS and the PNT domains, which are conserved in some members of the family, we showed that the GABP group , and not the ERG group, is the one most closely related to the ETS group. We also observed that the speed of accumulation of mutations in the various genes of the family is highly variable, Noticeably, paralogous members of the ELK group exhibit strikingly different evolutionary speed suggesting th at the evolutionary pressure they support is very different.