Clonal Analysis Of Cmp44e, Which Encodes A Conserved Putative Transmembrane Protein, Indicates A Requirement For Cell Viability In Drosophila

We have identified the cmp44Egene which encodes a putative multi-pass transmembrane protein that is conserved from yeast to humans. The expression of cmp44E during embryogenesis is ubiquitous with notably higher levels in the CNS and brain. it is also expressed in the germline during the germarial stages as well as several later stages of oogenesis. Utilizing a P-element insertion ai the 5' end of cmp44E we have isolated several deletions, created by imprecise excision events, which eliminate most or all of iis coding region. Analysis of these deficiencies has revealed that cmp44E is an essential gene required for embryogenesis. Results obtained from germline clone analysis indicate that cmp44E is not only required in the germline stem cells early in oogenesis, but is also required in other tissues probably due to ii being required for cell viability. Finally using germline transformation, we have identified a minimal genomic fragment capable of fully rescuing a null allele of cmp44E. Dev. Genet. 23:264-274, 1998. (C) 1998 Wiley-Liss, Inc.