A new dinucleotide repeat polymorphism at the telomere of chromosome 21q reveals a significant difference between male and female rates of recombination.
We have used a half-YAC containing the human chromosome 21 long-arm telomere to clone, map, and characterize a new dinucleotide repeat polymorphism (D21S1575) close to 21qter. This marker is < 120 kb from the telomeric (TTAGGG)n sequences and is the most distal highly polymorphic marker on chromosome 21q. This marker has a heterozygosity of 71% because of a variable (TA)n repeat embedded within a long interspersed element (LINE) element. Genotyping of the CEPH families and linkage analysis provided a more accurate determination of the full length of the chromosome 21 genetic map. A highly significant difference was detected between male and female recombination rates in the telomeric region: in the most telomeric 2.3 Mb of chromosome 21q, recombination was only observed in male meioses.
Blouin
J L
JL
Division of Medical Genetics, Cantonal Hospital of Geneva, Switzerland.
Christie
D H
DH
Gos
A
A
Lynn
A
A
Morris
M A
MA
Ledbetter
D H
DH
Chakravarti
A
A
Antonarakis
S E
SE
D001483:Base Sequence; D002874:Chromosome Mapping; D002891:Chromosomes, Human, Pair 21; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D012737:Sex Factors; D016615:Telomere