Annelids on a roll: Part I
Annelids are emerging as good model system in the field of evo devo and the recent increase in the articles published in leading journals further indicates their importance in solving evolution puzzles.Now a days various annelids are being used to decipher different aspects of evo devo like Neurogenesis, segmentation and axis formation.Today we briefly look into four articles which appeared in leading scientific journals in last few months.
We will begin with an article from an Open access Journal BMC Developmental Biology by Milana A Kulakova et al. regarding Para Hox genes in Nereis virens.Antp class of transcription factors are known for their role in body plan organization and specification of different organs and tissues in bilaterian animals.In my last post i discussed about The three-gene ParaHox family descending from an ancestral gene cluster that existed before the evolution of the Bilateria.
Image Credit:
Milana A Kulakova,Charles E Cook and Tatiana F Andreeva
BMC Developmental Biology 2008, 8:61 doi:10.1186/1471-213X-8-61
All three para Hox genes are found in from deuterostomes(the sea urchin Strongylocentrotus purpuratus, the hemichordate Ptychodera flava,the ascidian Ciona intestinalis, and a number of mammals and lophotrochozoans ( the sipunculids Phascolion strombus and Nephasoma minuta,the polychaete annelid Capitella , the clitellate annelid Perionyx excavatus , and the chiton Nuttallochiton mirandus but so far not even a single ecdysozoan is reported to have all three para hox genes Gsx, Xlox, and Cdx including for the two for whom we have complete genome.Drosophila lack Xlox and C;elegans doesnot have Gsx and Xlox orthologs.
Authors report whole mount insitu Hybridization in larval and post larval worms using three fragments of Nereis virens ParaHox genes as probes.They also report that In Nereis virens the ParaHox genes participate in antero-posterior patterning of ectodermal and endodermal regions of the digestive tract.Results also indicate that para Hox genes show spatial but not temporal colinearity .Finally data obtained by expression patterns of para hox genes by Kulakova et al.strengthens the hypothesis that these genes are involved in antero-posterior patterning of the developing embryo (ectodermal and endodermal),rather then previous notion that these genes function only in the patterning of endodermal tissues.
Reference:
Kulakova MA, Cook CE, Andreeva TF.
ParaHox gene expression in larval and postlarval development of the polychaete Nereis virens (Annelida, Lophotrochozoa).
BMC Dev Biol. 2008 May 29;8:61.
Related Posts:
If you liked what you just read, you may want to subscribe to my
RSS FEED
Thanks for visiting!
[...] public links >> annelida Annelids on a roll: Part I Saved by virtuoso2199 on Thu 02-10-2008 Live Aquarium Fish – Coelenterates Urticant Saved by [...]
Leave your response!