Homozygous Hus1-like37 flies show normal locomotor activity rhythms.
Mutant larvae show cell cycle arrest after a 500Rad irradiation exposure. They also show a normal reduction in BrdU incorporation after a 4000Rad irradiation exposure.
Hus1-like37 flies are viable although female sterile.
Hus1-like37 mutant flies are sensitive to hydroxyurea and methyl methanesulfonate (MMS) but not to X-rays (2500 rad). Exposure to 10 or 20 mM hydroxyurea affects the survival of Hus1-like37 mutants, whereas treatment with 30 mM hydroxyurea eliminates almost all Hus1-like37 and Hus1-like37/Df(3R)110 mutant larvae. Relatively low doses of MMS (0.025%) causes almost 100% death of Hus1-like37 and Hus1-like37/Df(3R)110 mutant larvae. Most of the Hus1-like37mutants die as larvae. When Hus1-like37 homozygous first and early second instar larvae are separated from their heterozygous siblings before MMS treatment, only 19% survive to pupal stage, whereas 75% of their heterozygous siblings form pupae. For both genotypes around20% die as pharate adults.
Approximately 15.% of Hus1-like37 mutant larvae treated with 0.025% methyl methanesulfonate exhibit aneuploid nuclei, an approximately four-fold increase as compared with wild-type.
Treatment of Hus1-like37 mutant flies with 4000 rads of irradiation does not result in a decresase of homozygous flies relative to untreated controls. Similar to wild-type, Hus1-like37 mutant discs contain very few mitotic cells after irradiation. Four hours after irradiation, Hus1-like37 mutant discs exhibit wild-type levels of apoptosis, indicating that Hus1-like is not required for post-irradiation induction of apoptosis.
Approximately 92% of eggs laid by Hus1-like37 mutant mothers exhibit nuclear defects, where the nucleus is found in a variety of conformations including the smooth spherical wild-type shape, oblong shape, or in several separate pieces along the nuclear periphery. Similar defects are generated from Hus1-like37/Df(3R)110 mothers.