To understand the basis for the Nob-1 phenotype, we analyzed embryonic lineages in animals homozygous for ct223 using a 4D microscope. We find no obvious alterations in lineages that give rise to posterior hypodermis, muscle and neurons. We do, however, observe variable defects in the Ep lineage that suggest Ep is adopting a fate similar to Ea. Staining with MH27 antibody reveals defects in shape and position of posterior ventral hypodermis during enclosure. In addition, the posterior seam cells fail to elongate and fewer express a wIs1 seam cell-specific reporter.
Mosaic analysis is in progress.
Since nob-1 resides in a gap in the physical map, we are also identifying fosmid clones that may contain the gene, in preparation for cloning.