MEIOTIC CROSSINGOVER IS NOT A SINGLE-SOUR CE OF RECOMBINANTS IN HUMANMALES

On the basis of chiasma distributions along bivalents in human male me iosis, genetic were counted for several chromosomal segments. These es timates appeared to be lower than the lengths corresponding genetic le ngths produced in the recombination analysis. When al so cytological d istances and numbers of markers used in multilocus mapping were taken into account, the regression estimates of genetic lengths were shown t o satisfactorily fit the observed values. This indicates that mitotic crossingover, genetic conversion, mutation and errors in allel's ident ification in addition to meiotic crossingover, appear to contribute to the observed genetic maps. It is suggested that these namely events, rather than the typing errors suggested by Morton (1991), seem observe d over those predicted on the basis of chiasma counts.