Desvio de segregação em humanos / Segregation distortion in humans
AUTOR(ES)
Monize Lazar Magalhães
FONTE
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia
DATA DE PUBLICAÇÃO
23/03/2011
RESUMO
The transmission ratio distortion (TRD), a biological process defined as a deviation from Mendelian predictions, is caused by different mechanisms: nonrandom segregation of chromosomes during meiosis or gametic and postzygotic viability selection. In order to investigate TRD in humans, we have studied a family with an overtransmitted pathogenic deletion in the CAPN3 gene (CAPN3 c.759_761del), previously associated to limb-girdle muscular dystrophy type 2A (LGMD2A). Initially, it was possible to define a 2.1 Mb region which was present in most of the individuals. The direct sequencing of 14 genes contained in this interval did not reveal rare variants that could be responsible for the advantage of gametes carrying the CAPN3 mutation. Nevertheless, common variants identified in five genes could indicate that the observed transmission distortion is caused by the interaction among proteins with small dissimilarities, resulting in differential performance of these gametic cells. Subsequently we developed another approach: spermatozoa from healthy individuals were sorted according to their motility and allelic frequencies at each locus in heterozygous state were compared in order to identify genomic regions susceptible to TRD. Surprisingly, some statistically significant results were achieved for regions containing genes involved with acrosome reaction and sperm motility, as PDE1 and PDE4, suggesting these processes are targets of the selection that ends in offspring with proportions skewed away from the Mendelian predictions. These results are important for enlarge our knowledge about TRD and its impact in humans, considering possible effects in male fertility
ASSUNTO(S)
desvio de segregação motilidade espermática segregation distortion sperm motility
Documentos Relacionados
- Segregation distortion in myotonic dystrophy.
- Genetic mapping by molecular markers with gametic and genotypic segregation distortion
- Temperature Sensitivity of Segregation-Distortion in DROSOPHILA MELANOGASTER
- On the Models of Segregation Distortion in DROSOPHILA MELANOGASTER
- A Modified Model of Segregation Distortion in DROSOPHILA MELANOGASTER