M. Jaarola et al., DIRECT EVIDENCE FOR SUPPRESSION OF RECOMBINATION WITHIN 2 PERICENTRICINVERSIONS IN HUMANS - A NEW SPERM-FISH TECHNIQUE, American journal of human genetics, 63(1), 1998, pp. 218-224
Crossover within a pericentric inversion produces reciprocal recombina
nt 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 inve
rsions. YAC probes were selected from within the q- and p-arm flanking
regions of two human inversions, and two-color FISH analysis was perf
ormed on sperm from heterozygous inversion carriers. A total of 6,006
sperm were analyzed for chromosome 1 inversion (p31q12), and 3,168 wer
e analyzed for chromosome 8 inversion (p23q22). Both inversions displa
yed suppression of crossing-over, although the amount of suppression d
iffered 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 ch
romosome 1 inversion, the recombination frequency of 0.4% reported her
e was below the limits of detection of the fusion technique. The simpl
icity of the FISH technique and the ease of scoring facilitate analysi
s of a sample-population size much larger than previously had been pos
sible.