Direct evidence for suppression of recombination within two pericentric inversions in humans: a new sperm-FISH technique.
Crossover within a pericentric inversion produces reciprocal recombinant chromosomes that are duplicated/deficient for all chromatin distal to the breakpoints. In view of this fact, a new technique is presented for estimating the frequency of recombination within pericentric inversions. YAC probes were selected from within the q- and p-arm flanking regions of two human inversions, and two-color FISH analysis was performed on sperm from heterozygous inversion carriers. A total of 6,006 sperm were analyzed for chromosome 1 inversion (p31q12), and 3,168 were analyzed for chromosome 8 inversion (p23q22). Both inversions displayed suppression of crossing-over, although the amount of suppression differed between the two inversions. The recombination frequency of 13.1% recorded for chromosome 8 inversion was similar to the frequency of 11.4% previously estimated by the human/hamster-fusion method. For chromosome 1 inversion, the recombination frequency of 0. 4% reported here was below the limits of detection of the fusion technique. The simplicity of the FISH technique and the ease of scoring facilitate analysis of a sample-population size much larger than previously had been possible.
Jaarola
M
M
Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA.
Martin
R H
RH
Ashley
T
T
D000818:Animals; D002459:Cell Fusion / Q000235:genetics; D002871:Chromosome Banding; D019457:Chromosome Breakage / Q000235:genetics; D007446:Chromosome Inversion; D002875:Chromosomes / Q000235:genetics*; D018244:Chromosomes, Artificial, Yeast / Q000235:genetics; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D006224:Cricetinae; D003434:Crossing Over, Genetic / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008297:Male; D011995:Recombination, Genetic / Q000235:genetics*; D013094:Spermatozoa / Q000473:pathology