Localized breakdown in linkage disequilibrium does not always predict sperm crossover hot spots in the human MHC class II region.
To investigate the relationship between meiotic crossover hot spots and block-like linkage disequilibrium (LD), we have extended our high-resolution studies of the human MHC class II region to a 90-kb segment upstream of the HLA-DOA gene. LD blocks in this region are not as well defined as in the neighboring 210-kb DNA segment but do show two regions of LD breakdown in which coalescent analysis indicates substantial historical recombination. Sperm crossover analysis of one region revealed a novel localized hot spot similar in intensity and morphology to most other MHC hot spots. Crossovers at this hot spot are not obviously affected by a large insertion/deletion polymorphism near the hot spot. The second region of LD breakdown, within the DPB1 gene, shows an extremely low level of sperm crossover activity and does not contain a sperm crossover hot spot. These results highlight the complexity of LD patterns and the importance of experimentally verifying crossover hot spots.
Kauppi
Liisa
L
Department of Genetics, University of Leicester, Leicester LE1 7RH, UK. kauppiL@mskcc.org
Stumpf
Michael P H
MP
Jeffreys
Alec J
AJ
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D002874:Chromosome Mapping; D024161:Collagen Type XI / Q000235:genetics; D003434:Crossing Over, Genetic / Q000235:genetics*; D005838:Genotype; D006239:Haplotypes; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D016254:Mutagenesis, Insertional; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D017384:Sequence Deletion; D013094:Spermatozoa / Q000378:metabolism*
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; C499319:COL11A2 protein, human; D024161:Collagen Type XI; D000949:Histocompatibility Antigens Class II; C071692:TAP2 protein, human