ISSN:
1432-0983
Keywords:
Ascobolus immersus
;
Meiotic recombination
;
Mismatch correction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Crosses were set up, using the b2 locus of Ascobolus immersus, to detect and measure the restoration of the parental genotype of a chromatid from hetero-duplex. From the results it can be concluded that: (1) restoration occurs, and its frequency is comparable to the frequency of conversion; (2) the relative frequency of conversion and restoration on the two homologous chromatids is that expected if the disparity in conversion to mutant and to wild-type of the marker is caused by the decision whether to excise the mutant or wild-type chain. This decision is the same on both chromatids. However, when all data are pooled, a slight, but significant, excess of conversion over restoration is found. The cause of this in discussed; (3) the absence of an excess of restoration over conversion is taken to imply that, in this system, the length of heteroduplex formed in an event is continuous; (4) these findings support the interpretation of tetrads where a crossover is separated from conversion, that they arise by independent correction giving both conversion and restoration in a heteroduplex tract continuous with the crossover.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00420629
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