Abstract
Purpose: Recently, partial DAZ deletions on the Y chromosome were identified in infertile men. To determine the clinical importance of partial DAZ deletion, we studied the number of DAZ copies in a well-defined population of 47 fertile men.
Methods: The number of DAZ gene copies was determined by PCR assays, qualitative and quantitative DNA blot experiments.
Results: Using semi-quantitative Southern blot, no partial DAZ deletion was detected in fertile men. In many cases, the results were discordant with the PCR assays and qualitative DYS1-blot experiments suggesting that the molecular events detected by the later methods could reflect gene conversion events. Many fertile men present four copies of the DAZ genes but an atypical organization of this DAZ locus. No difference in sperm concentration and motility in the fertile men were observed according to the different DAZ-haplotypes.
Conclusion: The different DAZ-haplotypes are compatible with normal spermatogenesis.
Keywords: DAZ gene, male infertility, PCR, Southern blot, Y chromosome
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References
- 1.Thonneau P, Marchand S, Tallec A, Ferial ML, Ducot B, Lansac J, Lopes P, Tabaste JM, Spira A. Incidence and main causes of infertility in a resident population (1,850,000) of three French regions (1988–1989) Hum Reprod. 1991;6:811–816. doi: 10.1093/oxfordjournals.humrep.a137433. [DOI] [PubMed] [Google Scholar]
- 2.Vogt P, Chandley AC, Hargreave TB, Keil R, Ma K, Sharkey A. Microdeletions in interval 6 of the Y chromosome of males with idiopathic sterility point to disruption of AZF, a human spermatogenesis gene. Hum Genet. 1992;89:491–496. doi: 10.1007/BF00219172. [DOI] [PubMed] [Google Scholar]
- 3.Reijo R, Lee TY, Salo P, Alagappan R, Brown LG, Rosenberg M, Rozen S, Jaffe T, Straus D, Hovatta O, et al. Diverse spermatogenic defects in humans caused by Y chromosome deletions encompassing a novel RNA-binding protein gene. Nat Genet. 1995;10:383–393. doi: 10.1038/ng0895-383. [DOI] [PubMed] [Google Scholar]
- 4.Reijo R, Alagappan RK, Patrizio P, Page DC. Severe oligozoospermia resulting from deletions of azoospermia factor gene on Y chromosome. Lancet. 1996;347:1290–1293. doi: 10.1016/s0140-6736(96)90938-1. [DOI] [PubMed] [Google Scholar]
- 5.Krausz C, Forti G, McElreavey K. The Y chromosome and male fertility and infertility. Int J Androl. 2003;26:70–75. doi: 10.1046/j.1365-2605.2003.00402.x. [DOI] [PubMed] [Google Scholar]
- 6.Kuroda-Kawaguchi T, Skaletsky H, Brown LG, Minx PJ, Cordum HS, Waterston RH, Wilson RK, Silber S, Gates R, Rozen S, Page DC. The AZFc region of the Y chromosome features massive palindromes and uniform recurrent deletions in infertile men. Nat Genet. 2001;29:279–286. doi: 10.1038/ng757. [DOI] [PubMed] [Google Scholar]
- 7.Saxena R, de Vries JW, Repping S, Alagappan RK, Skaletsky H, Brown LG, Ma P, Chen E, Hoovers JM, Page DC. Four DAZ genes in two clusters found in the AZFc region of the human Y chromosome. Genomics. 2000;67:256–267. doi: 10.1006/geno.2000.6260. [DOI] [PubMed] [Google Scholar]
- 8.Skaletsky H, Kuroda-Kawaguchi T, Minx PJ, Cordum HS, Hillier L, Brown LG, Repping S, Pyntikova T, Ali J, Bieri T, Chinwalla A, Delehaunty A, Delehaunty K, Du H, Fewell G, Fulton L, Fulton R, Graves T, Hou SF, Latrielle P, Leonard S, Mardis E, Maupin R, McPherson J, Miner T, Nash W, Nguyen C, Ozersky P, Pepin K, Rock S, Rohlfing T, Scott K, Schultz B, Strong C, Tin-Wollam A, Yang SP, Waterston RH, Wilson RK, Rozen S, Page DC. The male-specific region of the human Y chromosome is a mosaic of discrete sequence classes. Nature. 2003;423:825–837. doi: 10.1038/nature01722. [DOI] [PubMed] [Google Scholar]
- 9.Fernandes S, Huellen K, Goncalves J, Dukal H, Zeisler J, Rajpert De Meyts E, Skakkebaek NE, Habermann B, Krause W, Sousa M, Barros A, Vogt PH. High frequency of DAZ1/DAZ2 gene deletions in patients with severe oligozoospermia. Mol Hum Reprod. 2002;8:286–298. doi: 10.1093/molehr/8.3.286. [DOI] [PubMed] [Google Scholar]
- 10.Ferlin A, Bettella A, Tessari A, Salata E, Dallapiccola B, Foresta C. Analysis of the DAZ gene family in cryptorchidism and idiopathic male infertility. Fertil Steril. 2004;81:1013–1018. doi: 10.1016/j.fertnstert.2003.08.053. [DOI] [PubMed] [Google Scholar]
- 11.Fernandes S, Paracchini S, Meyer LH, Floridia G, Tyler-Smith C, Vogt PH. A large AZFc deletion removes DAZ3/DAZ4 and nearby genes from men in Y haplogroup N. Am J Hum Genet. 2004;74:180–187. doi: 10.1086/381132. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.de Vries JW, Hoffer MJ, Repping S, Hoovers JM, Leschot NJ, van der Veen F. Reduced copy number of DAZ genes in subfertile and infertile men. Fertil Steril. 2002;77:68–75. doi: 10.1016/s0015-0282(01)02935-1. [DOI] [PubMed] [Google Scholar]
- 13.de Vries JW, Repping S, van Daalen SK, Korver CM, Leschot NJ, van der Veen F. Clinical relevance of partial AZFc deletions. Fertil Steril. 2002;78:1209–1214. doi: 10.1016/s0015-0282(02)04390-x. [DOI] [PubMed] [Google Scholar]
- 14.Bienvenu T, Patrat C, McElreavey K, de Almeida M, Jouannet P. Reduction in the DAZ gene copy number in two infertile men with impaired spermatogenesis. Ann Genet. 2001;44:125–128. doi: 10.1016/s0003-3995(01)01078-4. [DOI] [PubMed] [Google Scholar]
- 15.Lambert B. The frequency of mumps and mump orchitis and the consequences for sexuality and fertility. Acta Genet Statist Med. 1951;2:1–16. [PubMed] [Google Scholar]
- 16.Organization WH. WHO Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Intercation. Cambridge: Cambridge Univesrity Press; 1999. [Google Scholar]
- 17.David G, Bisson JP, Czyglik F, Jouannet P. Anomalies morphologiques du spermatozoide hurnain. 1) Propositions pour un systeme de classification. J Gynecol Obstet Biol Reprod. 1975;Suppl(l):17–36. [Google Scholar]
- 18.Jouannet P, Ducot B, Feneux D, Spira A. Male factors and the likelihood of pregnancy in infertile couples. I. Study of sperm characteristics. Int J Androl. 1988;11:379–394. doi: 10.1111/j.1365-2605.1988.tb01011.x. [DOI] [PubMed] [Google Scholar]
- 19.Mitchell MJ, Woods DR, Tucker PK, Opp JS, Bishop CE. Homology of a candidate spermatogenic gene from the mouse Y chromosome to the ubiquitin-activating enzyme El. Nature. 1991;354:483–486. doi: 10.1038/354483a0. [DOI] [PubMed] [Google Scholar]
- 20.Saut N, Terriou P, Navarro A, Levy N, Mitchell MJ. The human Y chromosome genes BPY2, CDY1 and DAZ are not essential for sustained fertility. Mol Hum Reprod. 2000;6:789–793. doi: 10.1093/molehr/6.9.789. [DOI] [PubMed] [Google Scholar]
- 21.Yen PH, Chai NN, Salido EC. The human DAZ genes, a putative male infertility factor on the Y chromosome, are highly polymorphic in the DAZ repeat regions. Mamm Genome. 1997;8:756–759. doi: 10.1007/s003359900560. [DOI] [PubMed] [Google Scholar]
- 22.Glaser B, Yen PH, Schempp W. Fibre-fluorescence in situ hybridization unravels apparently seven DAZ genes or pseudogenes clustered within a Y-chromosome region frequently deleted in azoospermic males. Chromosome Res. 1998;6:481–486. doi: 10.1023/a:1009256613348. [DOI] [PubMed] [Google Scholar]
- 23.Repping S, Skaletsky H, Brown L, van Daalen SK, Korver CM, Pyntikova T, Kuroda-Kawaguchi T, de Vries JW, Oates RD, Silber S, van der Veen F, Page DC, Rozen S. Polymorphism for a 1.6-Mb deletion of the human Y chromosome persists through balance between recurrent mutation and haploid selection. Nat Genet. 2003;35:247–251. doi: 10.1038/ng1250. [DOI] [PubMed] [Google Scholar]
- 24.Rozen S, Skaletsky H, Marszalek JD, Minx PJ, Cordum HS, Waterston RH, Wilson RK, Page DC. Abundant gene conversion between arms of palindromes in human and ape Y chromosomes. Nature. 2003;423:873–876. doi: 10.1038/nature01723. [DOI] [PubMed] [Google Scholar]
- 25.Vogt PH, Fernandes S. Polymorphic DAZ gene family in polymorphic structure of AZFc locus: Artwork or functional for human spermatogenesis? Apmis. 2003;111:115–126. doi: 10.1034/j.1600-0463.2003.11101161.x. [DOI] [PubMed] [Google Scholar]
- 26.Repping S, De Vries JW, Van Daalen SK, Korver CM, Leschot NJ, Van Der Veen F. The use of spermHALO-FISH to determine DAZ gene copy number. Mol Hum Reprod. 2003;9:183–188. doi: 10.1093/molehr/gag032. [DOI] [PubMed] [Google Scholar]