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PHENOTYPE DISTRIBUTIONS IN ASCI OF NEUROSPORA CRASSA
Author(s) -
Mitchell Mary B.
Publication year - 1964
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1964.tb06604.x
Subject(s) - neurospora crassa , biology , phenotype , genetics , linkage (software) , neurospora , polarity (international relations) , distribution (mathematics) , evolutionary biology , gene , mathematics , mutant , mathematical analysis , cell
Fourteen crosses are described from which 3103 asci were dissected and scored with respect to phenotype distribution patterns of 1, 2 or 3 markers. The results illustrate the following points. There may regularly occur preferred ratios, including 8:1, 4:1, 2:1 and 1:2, of first to second division segregation patterns. Variations in this ratio (designated here as S/C, meaning simple to complex phenotype distribution patterns), shown by the same marker in different crosses, may regularly be discontinuous in that the ratio may shift from one preferred value to another. Values of linkage‐correction factors applicable to certain crosses suggest that these factors also may constitute a discontinuous series. Control of phenotype distributions in asci by a systematic, but unknown, mechanism is thought to be suggested. Characteristics of the order of isolation of asci, from 2 crosses treated in a special way, are consistent with the possibility that members of adjacently formed, twin asci are frequently, or even regularly, alike with respect to phenotype distribution class.