Regeneration of the germline in the annelid Capitella teleta.

The germline is essential for sexual reproduction and survival of the species. In many metazoans, the developmental potential to generate a distinct germline is segregated from somatic cell lineages early in embryogenesis, suggesting that the unique features of the germline must be established from its onset. Previous studies suggest that germ cells cannot regenerate once removed from the embryo, but few animals have been experimentally tested.

Regulative capacity for eye formation by first quartet micromeres of the polychaete Capitella teleta.

The stereotypic cleavage pattern shared by spiralian embryos provides unique opportunities to compare mechanisms of cell fate specification of homologous blastomeres, and can give insights into how changes in fate may have influenced the evolution of novel structures and morphological diversity. The potential of cells to undergo regulation and the timing of cell fate specification were investigated during early development in the polychaete annelid, Capitella teleta. Targeted laser deletions of the first quartet micromeres were performed, with a focus on the eye-forming cells 1a and 1c.