Microdeletions of a Y-specific marker, Yfm1, and implications for a role in spermatogenesis.
We have detected deletions of a Y-specific microsatellite marker, Yfm1, located on the Y chromosome (Yq) within interval 6 and near the DAZ (deleted in azoospermia) genes, in 9/89 oligospermic and 17/68 azoospermic Japanese men. No Yfm1 deletions were detected in the 150 normal fertile males examined as controls. Yfm1 deletions in the oligo- and azoospermic males were associated with other deletions that removed entire DAZ genes in those infertile men. These deletions indicated that all Yfm1 loci are located within azoospermia factor c (AZFc) in interval 6 on the long arm of the Y chromosome. Mapping Yfm1 on the Y chromosome using the draft sequence of the human genome revealed that at least three Yfm1 loci are located within about 25-30 kbp of the DAZ genes. Moreover, the Yfm1 marker showed the least number of copies in Japanese males derived from a Y chromosomal lineage called haplotype II, defined by having the Y Alu polymorphism (YAP) insertion. Males from this haplotype II lineage are known from our previous studies to have lower spermatogenic abilities, with higher rates of oligo- and azoospermia than other haplotypes. The least number of Yfm1 loci, whose copy number may correspond to that of the DAZ genes, may be a risk factor predisposing an individual to azoospermia or oligospermia.
Ewis
Ashraf A
AA
Department of Public Health, School of Medicine, University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan.
Lee
Juwon
J
Shinka
Toshikatsu
T
Nakahori
Yutaka
Y
D020087:Alu Elements; D000075364:Deleted in Azoospermia 1 Protein; D017353:Gene Deletion; D018628:Gene Dosage; D056426:Genetic Loci; D015894:Genome, Human; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D009845:Oligospermia / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics*; D029589:Seminal Plasma Proteins / Q000235:genetics; D013091:Spermatogenesis / Q000235:genetics*; D014998:Y Chromosome / Q000235:genetics*
C095668:DAZ1 protein, human; D000075364:Deleted in Azoospermia 1 Protein; D016601:RNA-Binding Proteins; D029589:Seminal Plasma Proteins