Abstract
Maternal hemizygosity of the 21 B8.C1-21 C8.D1 aristaless region of chromosome 2L of Drosophila melanogaster leads to high levels of embryonic mortality from the cross of Df(2L) al/+ females x +/+ males. The 21 B8.C1-21 C8.D1 polytene section therefore carries maternally active genes essential for embryogenesis. Selective screening for female sterile mutants against Df(2L) al yielded six alleles of a new female sterile embryonic lethal. This confirms the assumption that genomic regions that are maternally haplo-insufficient for normal embryogenesis house maternally active gene(s). It also demonstrates that mutational analysis of similar genomic regions can identify maternally acting embryonic lethal loci which escaped detection in spite of extensive screening experiments.
