Genetic Analyses of Mutations in Show Maternal-Effect Lethality and Interactions with Genes.

ELYS determines the subcellular localizations of Nucleoporins (Nups) during interphase and mitosis. We made loss-of-function mutations of in and found that ELYS is dispensable for zygotic viability and male fertility but the maternal supply is necessary for embryonic development. Subsequent to fertilization, mitotic progression of the embryos produced by the mutant females is severely disrupted at the first cleavage division, accompanied by irregular behavior of mitotic centrosomes. The introgression from shows close resemblance to that of the mutations, suggesting a common role for those proteins in the first cleavage division. Our genetic experiments indicated critical interactions between ELYS and three Nup107-160 subcomplex components; hemizygotes of either , or were lethal in the genetic background of the mutation. Not only and but also of behave as recessive hybrid incompatibility genes with An evolutionary analysis indicated positive natural selection in the ELYS-like domain of ELYS. Here we propose that genetic incompatibility between and may lead to reproductive isolation between and , although direct evidence is necessary.