Oocytes from All-Compound females produce anaphase I and meiosis II figures 64% of the time, i.e. they have bypassed metaphase I arrest.
Chromosome shows a significant amount of chromatid stretching during mitotic anaphase compared to wild type.
Distortion in paternal transmission of C(2)EN is established before fertilization. C(2)EN-bearing sperm are selectively lost after sperm transfer to the female and before storage of sperm in the seminal receptacles and spermathecae. This is consistent with a model of meiotic drive in which aberrations occurring early in meiosis lead ultimately to sperm dysfunction.
Provides all of chromosome 2 necessary for normal development. C(2)EN-bearing flies produce two types of meiotic products with respect to chromosome 2; half disomic and half nullosomic. Accordingly crosses to normal diploids produce mainly inviable mono- and triplo-2 zygotes; however crosses of C(2)EN flies to each other produce progeny. Transmission of C(2)EN by males versus that from females varies from about 30% to very low values (see also Robbins, 1977, Genetics 87: 67-81). This is attributed to zygote mortality by Novitski et al.; however, it may be reflected in defects in spermatogenesis as seen in cross sections of bundles of elongated sperm tails. Male transmission ratio is sensitive to the particular Y chromosome present (Strommen, 1982, Mol. Gen. Genet. 187: 126-31). Sex-chromosome disjunction in both sexes influenced by C(2)EN (Falk, 1982, Genet. Res. 41: 17-28); in XY/0 males the XY segregates preferentially from the compound; in X/Y males and X/X females, sex chromosome nondisjunction is elevated with the sex chromosomes segregating preferentially away from C(2)EN. In general, C(2)EN-bearing flies perform poorly in stocks and crosses.
Synthesized by first selecting a T(Y;2) with a break in YL of BSYy+ and an absolutely terminal break in 2L and next transferring the terminal YL to C(2L)RM by recombination in a Dp(Y;2)/C(2L)RM/C(2R)RM triploid; the terminal YL was homozygosed to produce C(2LYL)RM, BS. Irradiated C(2LYL)RM, BS/C(2R) females were crossed to C(2L); F(2R)/F(2R) males; this cross selects for progeny that receive C(2LYL)RM, BS plus a single copy of 2R from their mothers; those with wider Bar eyes are putative results of a translocation between the base of 2R from C(2R)RM and a terminal YL of C(2LYL)RM and the surviving offspring are YL2L.2L2R/F(2R); crosses of females of this constitution to C(2L)RM; C(2R)RM have yielded C(2)EN-bearing progeny as a consequence of fertilization of an ovum that has received a derivative homozygous (non BS) for the 2L2R arm of the compound and no F(2R) by a nullo-2 sperm. In situ hybridization with a telomeric probe reveals the presence of telomeric sequences at the junction between 2L and 2R (Goldstein, Berry and Novitski, 1984, D. I. S. 60: 117).
A study of metaphase arrest found that crossovers between homologs attached to the same centromere do not induce metaphase arrest. Hence exchanges induce metaphase arrest only when they physically conjoin two separate kinetochores. The signal that mediates metaphase arrest is not the exchange event per se, but the resulting tension on homologous kinetochores.
Chromosome does not increase the error frequency of the late larva neuroblast divisions. In the syncytial embryonic nuclear divisions, the chromosome produces a 10-fold increase in division errors relative to embryos with a normal karotype.
Genetic analysis demonstrates that the sex chromosome of the male directly correlates with the proportion of successful sperm carrying the C(2)EN chromosome: the information on the Y chromosome influences the rate of C(2)EN transmission in the male.
C(2)EN, 2R2L - 2L2R.