Amino acid replacement: R224C.
Homozygous males show a high frequency of X-Y chromosome nondisjunction in meiosis (31.2%).
Homozygous, mod(mdg4)Z3-3401/Df(3R)GC14 and mod(mdg4)Z3-3401/mod(mdg4)T16 males show a low frequency of 4th chromosome loss in meiosis (3.3%, 5.2% and 7.9% respectively).
mod(mdg4)Z3-3401/Df(3R)GC14 males show a moderate frequency of chromosome 2 nondisjunction in meiosis (16.9%).
Defects are seen in meiosis I in homozygous spermatocytes; although the chromosomes condense normally, the homologs are frequently unpaired at prometaphase I and metaphase I. Anaphase I is disorganised, with chromosomes migrating to the poles asynchronously. 54% of meiosis I poles have nuclei of unequal sizes, indicative of meiosis I nondisjunction. Meiosis II chromosome morphology and segregation appear normal. Spindle structure and kinetochore function appear normal at both divisions.
Homologous pairing in pre-meiotic spermatogonia and in early prophase I spermatocytes appears normal in mod(mdg4)Z3-3401/mod(mdg4)T16 males.
mod(mdg4)Z3-3401/Df(3R)GC14 females do not show increased X chromosome nondisjunction compared to controls and the frequency of recombination in large intervals on the X, second and third chromosomes in the mutant females is normal.
mod(mdg4)Z3-3401/Df(3R)GC14 is an enhancer of abnormal body color phenotype of y2
mod(mdg4)Z3-3401/mod(mdg4)T16, y2 has chaeta phenotype
Body colour: y2 ; mod(mdg4)Z3-3401/mod(mdg4)T16 flies have a y- phenotype (yellow bristles, wings and bodies).
mod(mdg4)Z3-3401 is rescued by mod(mdg4)MNM.hs.EGFP
mod(mdg4)Z3-3401 is partially rescued by mod(mdg4)+t7.5
mod(mdg4)Z3-3401/mod(mdg4)T16 is partially rescued by mod(mdg4)+t7.5
mod(mdg4)Z3-3401 fully complements the lethal/semi-lethal phenotypes of the following mod(mdg4) alleles, but they fail to complement mod(mdg4)Z3-3401 with respect to X-Y chromosome nondisjunction in male meiosis, with the transheterozygotes showing a high level of X-Y nondisjunction (frequency is indicated in parentheses after each allele); mod(mdg4)T16 (39.6%), mod(mdg4)142Δ10 (49.3%), mod(mdg4)142Δ33 (49.1%), mod(mdg4)142Δ15 (42.1%), mod(mdg4)142Δ32 (28.3%), mod(mdg4)142Δ29 (46%), mod(mdg4)142Δ49 (54.9%), mod(mdg4)neo129 (41.2%), mod(mdg4)02 (32.1%), mod(mdg4)03 (34.9%), mod(mdg4)20 (45.8%), mod(mdg4)117 (47.2%), mod(mdg4)269 (49.5%), mod(mdg4)324 (44.4%) and mod(mdg4)340 (54.1%).
mod(mdg4)Z3-3401 fully complements the lethal/semi-lethal phenotypes of the following mod(mdg4) alleles, and they partially or fully complement mod(mdg4)Z3-3401 with respect to X-Y chromosome nondisjunction in male meiosis, with the transheterozygotes showing only a low level of X-Y nondisjunction (frequency is indicated in parentheses after each allele); mod(mdg4)eGp4 (2.94%) and mod(mdg4)B2 (0%).
mod(mdg4)T6 fully complements mod(mdg4)Z3-3401 with respect to X-Y chromosome nondisjunction in male meiosis.
mod(mdg4)Z3-3401 strongly (but not completely) complements mod(mdg4)Z3-5578 and mod(mdg4)Z3-3298; transheterozygotes show only a low level of X-Y nondisjunction in male meiosis (frequency is indicated in parentheses after each allele); frequency is mod(mdg4)Z3-5578 (1.42%) and mod(mdg4)Z3-3298 (1.09%).