The remaining crossovers are distributed abnormally, and chiasma interference is reduced. Synaptonemal complex is normal, but recombination nodules are reduced in number, often have abnormal morphology, and are found in regions of relatively decondensed chromatin. Mitotic defects in embryos derived from such females cause lethality at all stages. Most mei-41 alleles cause sensitivity to a wide range of DNA damaging agents, incuding MMS, X rays, and hydroxyurea. Heterozygotes display an intermediate level of sensitivity.
Larval neuroblasts show a high frequency of chromosome breakage and instability.
Brain squashes confirm this conclusion. In stock, mei-41 males often acquire an X chromosome bb mutation. Alleles mei-41 is a very large target for EMS mutagenesis. More than fifty alleles exist, some of which specifically affect DNA repair or meiotic recombination. A 10.4 kb genomic fragment contains full gene activity.