Slow as molasses is required for polarized membrane growth and germ cell migration in Drosophila.
Drosophila germ cell migration is directed by attractive and repulsive guidance cues. We have identified a novel gene, slow as molasses (slam), which is required for germ cell migration. In slam zygotic mutants, germ cells fail to transit off the midgut into the mesoderm. We show that slam is required at this stage in parallel to HMG Coenzyme A reductase, a previously identified germ cell migration gene. Removal of both zygotic and maternal slam results in an earlier defect: a failure to form a cellular blastoderm. Consistent with this phenotype, we found that slam is one of the earliest genes to be transcribed in the embryo, and Slam protein localizes to the growing basal-lateral membrane during blastoderm formation, but Slam is not detected during later stages of embryogenesis. Because slam RNA and protein are expressed earlier than the time when we observe defects in germ cell migration, we propose that Slam is required for the localization of a signal to the basal side of blastoderm cells that is needed later in the posterior midgut to guide germ cells.
Howard Hughes Medical Institute, Developmental Genetics Program, Skirball Institute at NYU School of Medicine, 540 First Avenue, New York, NY 10016, USA.
Jennifer A
JA
Stein
Heather Tarczy
HT
Broihier
Lisa A
LA
Moore
Ruth
R
Lehmann
D000595:Amino Acid Sequence; D000818:Animals; D001756:Blastoderm / Q000166:cytology / Q000378:metabolism; D019521:Body Patterning; D002465:Cell Movement; D004330:Drosophila / Q000166:cytology / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D017344:Genes, Insect; D005854:Germ Cells / Q000166:cytology; D017403:In Situ Hybridization; D008297:Male; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D012313:RNA / Q000235:genetics / Q000378:metabolism
D029721:Drosophila Proteins; D012313:RNA