Frimousse
frimousse (frm) is a spontaneous C. intestinalis mutation that was initially identified as having an anterior truncation. We have found that the anterior neural plate of frm/frm embryos initially forms, but is not maintained. Cells that would make the anterior neural plate are trans-fated to epidermis. The anterior brain (sensory vesicle), the palps (adhesive gland) and the mouth (stomodeum) are all absent.
At the 8-cell stage, the paired anterior/animal a4.2-blastomeres are fated to form rostral ectodermal derivatives including the anterior epidermis, anterior sensory vesicle, palps and stomodeum. By contrast, the paired anterior/vegetal A4.1-blastomeres give rise to the posterior nervous system [7.]. The frm larval phenotype was suggestive of a perturbation specific of the a-lineage. DiI lineage tracing and analysis of epidermal and neuronal markers demonstrate that cells that normally make anterior neural plate are instead becoming epidermis in the frm mutant. The mutation is restricted to a discrete lineage of the nervous system, and posterior CNS develops normally. Our initial description of this mutant has been published (Deschet K, and Smith WC. Curr Biol. 2004 Jun 8;14(11):R408-10). Erin Mulholland, a graduate student in the lab, is continuing this work.
