title: Spermatogenesis inDrosophila hydei: A genetic survey.
abstract: We constructed balancer-chromosomes for the large autosomes ofDrosophila hydei and screened more than 16000 chromosomes for male sterile mutations in order to dissect spermatogenesis genetically. 365 mutants on the X chromosome and the autosomes 2, 3, and 4 were recovered and analysed cytologically in squash preparations under phase-contrast optics. The majority of the mutations allows a rather advanced differentiation of the spermatozoa. At the light-microscopical level, it is possible to classify these mutations with respect to individualization, coiling or motility of the mutant spermatozoa. In contrast, a small number of mutants exhibits conspicuous, pleiotropic phenotypes. Gonial divisions, the shaping of the spermatocyte nucleus and male meiotic divisions are controlled by X chromosomal or autosomal genes which can mutate to male sterile alleles. A number of nonallelic 3rdchromosome male sterile mutations interfere with the unfolding of the Y chromosomal lampbrush loops. Other autosomal male sterile mutations modify the morphology of these lampbrush loops. Another group of mutations inhibits the formation of the nebenkern while the development of the spermatid nucleus and the flagellum can proceed. Such male sterile mutations can decouple the development of nucleus, protein body, nebenkern, and flagellum of the spermatid. Thus, we can describe spermatogenesis inDrosophila as the coordinate execution of the individual developmental programs of the different components of the spermatozoon.
authors.affiliation: Department of Molecular and Developmental Genetics, Catholic University of Nijmegen, Faculty of Science, Toernooiveld, NL-6525 ED, Nijmegen, The Netherlands.
authors.forename: Johannes H P
authors.initials: JH
authors.lastname: Hackstein
authors.affiliation: Department of Molecular and Developmental Genetics, Catholic University of Nijmegen, Faculty of Science, Toernooiveld, NL-6525 ED, Nijmegen, The Netherlands.
authors.forename: Heinz
authors.initials: H
authors.lastname: Beck
authors.affiliation: Department of Molecular and Developmental Genetics, Catholic University of Nijmegen, Faculty of Science, Toernooiveld, NL-6525 ED, Nijmegen, The Netherlands.
authors.forename: Ron
authors.initials: R
authors.lastname: Hochstenbach
authors.affiliation: Department of Molecular and Developmental Genetics, Catholic University of Nijmegen, Faculty of Science, Toernooiveld, NL-6525 ED, Nijmegen, The Netherlands.
authors.forename: Hannie
authors.initials: H
authors.lastname: Kremer
authors.affiliation: Department of Molecular and Developmental Genetics, Catholic University of Nijmegen, Faculty of Science, Toernooiveld, NL-6525 ED, Nijmegen, The Netherlands.|Institute of Zoology, University of Kiel, D-2300, Kiel, Federal Republic of Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Zacharias
keywords: Cellular differentiation; Drosophilia; Male sterile mutations; Spermatogenesis; Y chromosomal lampbrush loops