Extavour, CassandraGarcia-Bellido, A.2016-06-072001Extavour, Cassandra, and Antonio Garcia-Bellido. 2001. Germ cell selection in genetic mosaics in Drosophila melanogaster. Proceedings of the National Academy of Sciences 98, no. 20: 11341–11346. doi:10.1073/pnas.201409198.0027-8424http://nrs.harvard.edu/urn-3:HUL.InstRepos:27266718Heritable 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.en-USJournal Article2016-04-0120012016-06-0710.1073/pnas.201409198