Localized defects of blastoderm formation in maternal effect mutants of Drosophila.

摘要: Abstract In the three maternal effect lethal mutant strains of D. melanogaster described in this report, homozygous females produce defective eggs that cannot support normal embryonic development. The embryos from these begin to develop for first 2 hr after fertilization an apparently way, forming a blastula containing cluster pole cells at posterior end and layer syncytial blastoderm nuclei. During subsequent transition cellular blastoderm, cell formation is either partially or totally blocked. mat(3)1 no are formed, indicating there separate genetic controls cells. other two mutants form incomplete which certain regions remain noncellular. noncellular region mat(3)3 on posterior-dorsal surface, covering about 30% total blastoderm. mat(3)6 formed only anterior ends, separated by covers 70% selective effects emphasize importance components present egg before genes essential oogenesis not any period development, as indicated strict dependence phenotypes genotypes. Heterozygous die, whereas heterozygous into viable adults. One mutants, , has temperature-sensitive phenotype. Homozygous maintained restrictive temperature 29°C show effect. However, permissive 20°C adult progeny. occurs during last 12 oogenesis, consistent with phenotype mutant.