Germ cell selection in genetic mosaics in Drosophila melanogaster.
Heritable mutations in the germ line lead to genetically heterogeneous, or mosaic, gonads. Many of the genes used in germ-line development also play roles in somatic development [Saffman, E. E. & Lasko, P. (1999) Cell. Mol. Life Sci. 55, 1141-1163]. Mutations in these genes may have cellular phenotypes throughout germ-line development leading to their differential elimination or survival, as has been observed in somatic cells [Morata, G. & Ripoll, P. (1975) Dev. Biol. 42, 211-221]. We investigate whether mutations in heterozygosis are subject to pregametic selection in the germ line. We initiated clones of wild-type homozygous cells at different stages of development in gonads heterozygous for eight different recessive chromosome deficiencies. Here we show that cell selection takes place in mosaic germ-line populations. This phenomenon represents a level of selection that precedes and conditions subsequent zygotic selection by affecting the genes available in the gametic population.
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Museum Molecular Laboratory, University Museum of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom.
García-Bellido
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D000818:Animals; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics*; D005260:Female; D006579:Heterozygote; D007814:Larva / Q000528:radiation effects; D008297:Male; D008938:Mitosis; D009030:Mosaicism / Q000235:genetics*; D010053:Ovary / Q000166:cytology / Q000502:physiology; D011995:Recombination, Genetic / Q000528:radiation effects; D013094:Spermatozoa / Q000502:physiology* / Q000528:radiation effects; D014965:X-Rays; D015053:Zygote / Q000502:physiology*