title: Smoking-induced chromosomal segregation anomalies identified by FISH analysis of sperm.
abstract: BACKGROUND
  Numerical chromosome aberrations in gametes are directly related to infertility and aneuploid embryos. Previous studies have shown that toxic substances from cigarette smoke induce structural and numerical chromosomal aberrations in vitro and could potentially increase levels of aneusomy in sperm. Moreover, increased levels of aneusomy in sperm are correlated with low implantation rates, spontaneous abortions and fetal losses. Studies of chromosome 3 in sperm suggest it may be more prone to segregation anomalies than other autosomes, but there has been no systematic investigation of the incidence of disomy for chromosome 3 in sperm derived from donor male smokers. The objective of this study was to use FISH to evaluate the influence of smoking on the levels of disomy for chromosomes X and Y, and to determine whether disomy levels for chromosome 3 were elevated in sperm derived from male smokers.
  
  
  RESULTS
  FISH analysis was used to evaluate the frequency of disomies of chromosomes 3, X, and Y in sperm of 10 smokers, compared to a control group of 7 non-smoking fertile men. All the subjects presented a normal somatic karyotype. There was a significant increase in the overall frequency of disomies in sperm derived from the smoking group (P< 0.0001). When each chromosome pair was analyzed individually, disomy of chromosome 3 in smokers was found to be more than twice that observed in the matched non-smoker control group. In addition we observed a higher frequencies of disomy of the X and Y chromosomes, indicating elevated levels of diploidy in the sperm from the smoking group.
  
  
  CONCLUSIONS
  In this study we have shown that chromosome 3 may be susceptible to smoking-related segregation anomalies. Our results also suggest that errors can occur in both meiosis I and II, confirming the emerging literature that the male meiotic process may generally be affected by the genotoxic damage from tobacco use. Collectively, these findings provide additional evidence for enhancing tobacco control measures, and suggest that FISH analysis of chromosome 3 in sperm may be useful for monitoring smoking-induced segregation damage as part of the evaluation of infertile males.
authors.affiliation: Department of Genetics, Ribeirao Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Zip code 14049-900 Ribeirao Preto, SP Brazil.
authors.forename: Ciro Silveira
authors.initials: CS
authors.lastname: Pereira
authors.affiliation: Department of Genetics, Ribeirao Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Zip code 14049-900 Ribeirao Preto, SP Brazil.
authors.forename: Maria Silvina
authors.initials: MS
authors.lastname: Juchniuk de Vozzi
authors.affiliation: Department of Genetics, Ribeirao Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Zip code 14049-900 Ribeirao Preto, SP Brazil.
authors.forename: Silvio Avelino
authors.initials: SA
authors.lastname: Dos Santos
authors.affiliation: Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Ribeirão Preto, SP Brazil.
authors.forename: Maria Aparecida C
authors.initials: MA
authors.lastname: Vasconcelos
authors.affiliation: Department of Genetics, Ribeirao Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Zip code 14049-900 Ribeirao Preto, SP Brazil.
authors.forename: Cláudia Cp
authors.initials: CC
authors.lastname: de Paz
authors.affiliation: Department of Genetics, Ribeirao Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Zip code 14049-900 Ribeirao Preto, SP Brazil ; Department of Pathology and Molecular Medicine, Queen's University, 88 Stuart Street, Kingston, ON Canada.
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Squire
authors.affiliation: Department of Genetics, Ribeirao Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Zip code 14049-900 Ribeirao Preto, SP Brazil.
authors.forename: Lucia
authors.initials: L
authors.lastname: Martelli
keywords: Aneuploidy; Disomy; FISH; Male gametogenesis; Male infertility; Meiosis; Non-disjunction; Sperm; Tobacco consumption