A-A Translocations: Breakpoints and Stocks
A remarkable resource of cytogenetic modifications, far beyond those available in most other experimental species, is available in the reciprocal translocations between A chromosomes of maize. Translocations were originally found in the 1920s (Brink 1927; Burnham 1930) as spontaneously arising, segregating “semisteriles” (i.e., plants with 50% aborted pollen and eggs). Physical exchange of chromosome segments was revealed by cross-shaped configurations of four elements at pachytene (McClintock 1930). Numbers of translocations were isolated following X-irradiation (Anderson 1935; 64 additional translocations). The resource was greatly expanded with interchanges induced by exposure to nuclear explosions; these and the other collections were all characterized cytologically by Longley (1961). See the previous chapter by Patterson for a description of the transmission genetics of translocations.
KeywordsReciprocal Translocation Nuclear Explosion Previous Chapter Translocation Breakpoint Transmission Genetic
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