The germ line is specified in many animal embryos by maternal RNAs and proteins that are localized in a region of the egg called the germ plasm. The equivalent region in ascidian embryos seems to be the postplasm at the posterior pole but this region also contains somatic-cell determinants. On p. 2683,Shirae-Kurabayashi et al. propose that sea squirt postplasm regulates both germ- and somatic-cell differentiation through an asymmetric cell division that segregates the two types of determinants. Using CiVH, a homologue of the Drosophila germline-specific gene vasa, and other postplasm components as markers, the researchers show that the postplasm-containing blastomeres, the B7.6 cells, divide asymmetrically to form two distinct daughter cells: B8.11 and B8.12. The postplasmic components mainly segregate into the B8.11 cells, which later associate with the gut wall, but CiVH RNA and protein segregate into the B8.12 cells, which are incorporated into the gonad. This redistribution of specific maternal molecules into the B8.12 cells, the researchers suggest, drives germ-cell specification in ascidians.
Germ-cell specification the ascidian way
Germ-cell specification the ascidian way. Development 15 July 2006; 133 (14): e1402. doi:
Download citation file:
Advertisement
Cited by
Pathway to Independence programme

We’re excited to announce our new Pathway to Independence programme, aimed at supporting postdocs as they go on the job market. Find out more about the scheme in our Editorial.
Call for papers: Metabolic and Nutritional Control of Development and Regeneration

We are welcoming submissions for our next special issue, which will focus on metabolic and nutritional control of development and regeneration. Submission deadline: 15 May 2023.
Webinar: Increasing the visibility and impact of your research
-HUBSwebinar.jpg?versionId=4486)
Would you like to increase the visibility and impact of your research and raise your profile internationally? If so, register for the very practical webinar we are running in association with HUBS on 23 February 2023.
Transitions in development: Daniel Grimes

Daniel Grimes’s lab studies the consequences of ciliary mutations, including left-right patterning defects and scoliosis. We interviewed Daniel to find out more about his career path, his experience of becoming a group leader and the influence of Jurassic Park.
Preprints in Development
(update)-InPreprints.png?versionId=4486)
As part of our efforts to support the use of preprints and help curate the preprint literature, we are delighted to launch a new article type: ‘In preprints’. These pieces will discuss one or more recent preprints and place them in a broader context.