Variable levels of a heteroplasmic point mutation in individual hair roots.
During direct sequencing of the first hypervariable segment of the human mitochondrial control region, we identified one individual with a heteroplasmic point mutation at nt 16256.
We used primer extension to analyze the proportions of each mitochondrial haplotype in peripheral blood, buccal cells, and single hair roots from this individual and from eight members of his maternal lineage.
Significant levels of heteroplasmy were found in only three individuals, and, in these cases, the proportions of each haplotype were similar in both blood and buccal cells.
From the changes in mitochondrial haplotypes within mother-offspring pairs, we calculated that the most likely size of a mitochondrial bottleneck during development was 1-27 segregating units.
However, highly variable levels of heteroplasmy were found in single hair roots, even among roots from the same individual.
We analyzed a large number of hair roots from one individual and found that the proportion of one haplotype was within a range of 9% to>99% in different roots.
Roots originating from within a small patch of skin had haplotype proportions as variable as those from different areas of skin.
Mots-clés Pascal : Mitochondrie, DNA mitochondrial, Homme, Hétéroplasmie, Etude familiale, Comparaison intraindividuelle, Taux, Haplotype, Cellule sanguine, Cavité buccale, Cheveu, Racine pilaire, Exploration, Matériel biologique, Fiabilité structurelle, Mutation ponctuelle, Aspect médicolégal, Médecine légale, Cytogénétique, Biologie moléculaire, Métabolisme pathologie, Mitochondrie pathologie
Mots-clés Pascal anglais : Mitochondria, Mitochondrial DNA, Human, Heteroplasmy, Family study, Intraindividual comparison, Rate, Haplotype, Blood cell, Oral cavity, Hair (head), Pilar root, Exploration, Biological material, Structural reliability, Point mutation, Forensic aspect, Legal medicine, Cytogenetics, Molecular biology, Metabolic diseases, Mitochondrial disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0090035
Code Inist : 002B30A10. Création : 14/05/1998.