
%0 Journal Article
%A Degnan, BM 
%A Rohde, PR 
%A Lavin, MF 
%T Normal development and embryonic gene activity of the ascidian <I>Herdmania momus</I>
%J Marine and Freshwater Research
%D 1996/05/01
%V 47
%N 3
%P 543-551
%K 
%R https://doi.org/10.1071/MF9960543
%U https://www.publish.csiro.au/paper/MF9960543 
%X Embryonic and post-larval development of the tropical solitary ascidian Herdmania momus is shown to be similar to that of extensively studied ascidian model systems. H. momus development is rapid and temperature-dependent, with hatching occurring 8.5 h after fertilization at 28ºC. An increase in total embryonic gene transcription is detected at the 110-cell stage or the onset of gastrulation. Treatment of early embryos with actinomycin D inhibits transcription and curtails morphogenetic cell movement in the early gastrula without immediately inhibiting cell division. The prevalence of homeobox-containing transcripts increases around the 110-cell stage and later in development. Isolated H. momus homeobox genes, expressed at the tailbud stage, have greatest sequence identity to members of Hox, otd/Otx, eve/Evx and cad/Cdx homeobox classes. Evidence from H. momus and other ascidians suggests that urochordates possess most of the homeobox genes of the chordate HOX cluster. 
