Chromosome Measurements in Aged Monozygotic Twins
| Autor: | E. Moralishvili, L.F. Jarvik, F.S. Yen, T. Kato, J. Fleiss |
|---|---|
| Rok vydání: | 1971 |
| Předmět: |
Male
Aging Younger age Chromosomes Human 19-20 Twins Monozygotic twin Biology Pregnancy Short arms Chromosomes Human 21-22 and Y Leukocytes Genetics Humans Chromosomes Human 4-5 Genetics (clinical) Aged Chromosomes Human 16-18 Chromosomes Human 6-12 and X Analysis of Variance Sex Chromosomes Chromosomes Human 1-3 Chromosome Karyotype Karyotyping Female Chromosomes Human 13-15 Demography |
| Zdroj: | Human Heredity. 21:557-576 |
| ISSN: | 1423-0062 0001-5652 |
| DOI: | 10.1159/000152450 |
| Popis: | To ascertain whether the genotypic similarity of monozygotic twin partners is reflected in their chromosome measurements despite the crudeness of presently available techniques, the lengths of the long and short arms were measured in 10 cells (5 from each twin partner) from 10 pairs (3 male and 7 female) of aged monozygotic twins. In total, then, measurements were available from 100 cells, derived from peripheral leukocyte cultures of subjects ranging in age between 78 and 89 years. Measurements were made by hand, rather than computer, from photographic karyotypes as customarily constructed in cytogenetic laboratories. The centromeric index, rather than the arm ratio, proved mathematically to be the more precise measure of the relative position of the centromere and, supporting the recommendation of others, it is urged that it be the only measure used. Of the two parameters measuring relative total length, the one relative to the autosomal sum seems preferable to the one relative to the autosomal sum plus X on other than statistical grounds. Even though the present measurements were derived from aged twins, they are in general agreement with those reported in the literature for younger single borns and, like those of other investigators, show marked intraindividual variability combined with relatively low variability between persons. Nonetheless, there emerges for relative length, the seemingly more accurate of the two measures, the indication of greater homogeneity within pairs of monozygotic twins than between pairs. Larger samples, including younger age groups and dizygotic pairs, with many more cells per individual need to be studied before definitive conclusions can be drawn. |
| Databáze: | OpenAIRE |
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