02-P015 Dcamsap (ssp4) is a member of a family of membrane-skeleton proteins essential for the life of animals

The CAMSAP1 gene in vertebrates is a spectrin associated protein that is regulated by Ca2+/calmodulin. It is a member of a family of protein in animals, of unknown function, that contain a calponin homology (CH) domain and a conserved C-terminal DUF1781 domain. Invertebrates have single CAMSAP genes and vertebrates generally have three. The Drosophila homologue of CAMSAP1 is Dcamsap (ssp4). Transposon insertion mutations in Dcamsap are lethal. Fly embryos die before hatching with defects in head involution.

We have generated an antibody to the C-terminus of Dcamsap and investigated the expression of the gene using western blotting and by immunocytochemistry to whole-mount embryos. Expression is elevated in discrete cells that may be undergoing apoptosis. Analysis of both the insertion mutations and also dsRNAi knockdown of Dcamsap in the eye indicate that Dcamsap is required for regulation of cell number during development.