Magnification of the ribosomal genes in female Drosophila melanogaster.

Journal Article (Journal Article)

The genetically induced increase in the number of 18S + 28S ribosomal genes known as magnification has been reported to occur in male Drosophila but has not previously been observed in females. We now report that bobbed magnified (bbm) is recovered in progeny of female Drosophila carrying three different X bobbed (Xbb) chromosomes and the helper XYbb chromosome, which is a derivative of the Ybb- chromosome. Using different combinations of bb or bb+ X and Y chromosomes, we show that magnification in females requires both a deficiency in ribosomal genes and the presence of a Y chromosome: X/X females that are rDNA-deficient but do not carry a Y chromosome do not produce bbm; similarly, X/X/Y females that carry a Y chromosome but are not rDNA-deficient do not produce bbm. Bobbed magnified is only recovered from rDNA-deficient X/XY, X/X/Y or XX/Y females. We have also found that females carrying a ring Xbb chromosome together with the XYbb- chromosome do not produce bbm, indicating that ring X chromosomes are inhibited to magnify in females as in males. We postulate that the requirement for a Y chromosome is due to sequences on the Y chromosome that regulate or encode factor(s) required for magnification, or alternatively, affect pairing of the ribosomal genes.--These studies demonstrate that magnification is not limited to males but also occurs in females. Magnification in females is induced by rDNA-deficient conditions and the presence of a Y chromosome, and probably occurs by a mechanism similar to that in males.

Full Text

Duke Authors

Cited Authors

  • Komma, DJ; Endow, SA

Published Date

  • November 1986

Published In

Volume / Issue

  • 114 / 3

Start / End Page

  • 859 - 874

PubMed ID

  • 3098624

Pubmed Central ID

  • PMC1203017

International Standard Serial Number (ISSN)

  • 0016-6731

Digital Object Identifier (DOI)

  • 10.1093/genetics/114.3.859


  • eng

Conference Location

  • United States