, Volume 88, Issue 5, pp 349–373

Cytological and genetic analysis of the Y chromosome of Drosophila melanogaster

I. Organization of the fertility factors
  • Maurizio Gatti
  • Sergio Pimpinelli

DOI: 10.1007/BF00285858

Cite this article as:
Gatti, M. & Pimpinelli, S. Chromosoma (1983) 88: 349. doi:10.1007/BF00285858


By applying quinacrine-, Hoechst- and N-banding techniques to neuroblast prometaphase chromosomes the Y chromosome of Drosophila melanogaster can be differentiated into 25 regions defined by the degree of fluorescence, the stainability after N-banding and the presence of constrictions. Thus these banding techniques provide an array of cytological landmarks along the Y chromosome that makes it comparable to a polytene chromosome for cytogenetic analysis. — 206 Y-autosome translocations (half of them carrying Y-linked sterile mutations) and 24 sterile y+Y chromosomes were carefully characterized by these banding techniques and used in extensive complementation analyses. The results of these experiments showed that: (1) there are four linearly ordered fertility factors in YLand two fertility factors in YS. (2) These fertility factors map to characteristic regions of the Y chromosome, specifically stained with the N-banding procedure. (3) The most extensively analyzed fertility factors are defined by a series of cytologically non-overlapping and genetically noncomplementing breaks and deficiencies distributed over large chromosome regions. For example, the breakpoints which inactivate the kl-5 and ks-1 loci are scattered along regions that contain about 3,000 kilobases (kb) DNA. Since these enormous regions formally define single genetic functions, the fertility genes of the Y chromosome have an as yet unappreciated physical dimension, being larger than euchromatic genes by two orders of magnitude.

Copyright information

© Springer-Verlag 1983

Authors and Affiliations

  • Maurizio Gatti
    • 1
  • Sergio Pimpinelli
    • 1
  1. 1.Dipartimento di Genetica e Biologia MolecolareCittà UniversitariaRomaItaly

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