Evidence for a centrosome-attracting body like structure in germ-soma segregation during early development, in the urochordate Oikopleura dioica

BMC Developmental Biology

Henriette Busengdal¹  Ioannis Kourtesis²  Lisbeth Charlotte Olsen³ 

[1] Department of Biological Sciences, University of Bergen, Bergen, Norway;Department of Molecular Biology, University of Bergen, Bergen, Norway;Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway

关键词: Centrosome attracting body;    Pumilio;    Vasa;    Postplasmic/PEM transcripts;    Early development;    Cell fate;    Tunicates;   

DOI  :  10.1186/s12861-018-0165-5

学科分类：生物科学（综合）

来源: BioMed Central

【 摘 要 】

Germ cell formation has been investigated in sessile forms of tunicates. This process involves the release of a subset of maternal transcripts from the centrosome-attracting body (CAB) in the progenitor cells of the germ line. When germ-soma segregation is completed, CAB structures are missing from the newly formed primordial germ cells (PGCs). In free-swimming tunicates, knowledge about germ cell formation is lacking. In this investigation, comparative gene expression and electron microscopy studies were used to address germ cell formation in Oikopleura dioica (O. dioica). We found that the RNA localization pattern of pumilio (pum1) is similar to the pattern described for a subset of maternal transcripts marking the posterior end of ascidian embryos. Transcripts marking the posterior end are called postplasmic or posterior-end mark (PEM) transcripts. We found no localization of vasa (vas) transcripts to any sub-region within the germ-line precursor cells. Expression of vas4 was detected in the newly formed PGCs. Electron microscopy studies confirmed the presence of structures with similar morphology to CAB. In the same cytoplasmic compartment, we also identified pum1 transcripts and an epitope recognized by an antibody to histone H3 phosphorylated on serine 28. Our findings support that a CAB-like structure participates in the segregation of maternal pum1 transcripts during germ-soma separation in O. dioica.

【 授权许可】

CC BY