title: Bivalent behavior in Drosophila melanogaster males containing the In(1)sc4Lsc8RX chromosome.
abstract: The sex chromosome bivalent was examined in Drosophila melanogaster males possessing the In(1)sc4Lsc8R X chromosome. Three-dimensional reconstructions from electron micrographs of serially cut thin sections were made. A large proportion of the kinetochores of In(1)sc4Lsc8R/Y bivalents did not face opposite poles during metaphase I and anaphase I. This suggests that In(1)sc4Lsc8R/Y bivalents may have difficulty achieving bipolar stability. Delay in achieving bipolar stability could contribute to the nondisjunctional behavior found in In(1)sc4Lsc8R/Y males.
mesh_terms: D000818:Animals; D002453:Cell Cycle; D003433:Crosses, Genetic; D004331:Drosophila melanogaster / Q000235:genetics* / Q000502:physiology; D005260:Female; D008297:Male; D008540:Meiosis; D009154:Mutation; D014960:X Chromosome / Q000502:physiology*