A STUDY OF THE SOMATIC CHROMOSOME COMPLEMENT AMONG THE CHINESE
- VernacularTitle:中国人的有丝分裂染色体组型
- Author:
Min WU
;
Lihua LIN
- Publication Type:Journal Article
- From:
Acta Anatomica Sinica
1955;0(03):-
- CountryChina
- Language:Chinese
-
Abstract:
Leukocytes from peripheral blood of 70 normal Chinese,40 males and 30 females, were cultured in vitro according to a modification of Moorhead's method.Chromosome studies were carried out.Table I lists the results obtained including age group,metaphase plates counted and analysed and the chromosome number of each cell.92.4 per cent of 8031 counted cells had the diploid number(2n=46).Chromosome measurements were made from camera lucida drawings.Measurements were estimated to the nearest 0.1 mm on a fine metric scale.The relative length,arm ratio and centromere index of each chromosome were calculated from measurements of 18 haploid chromosome sets of 11 metaphase plates in 6 males and 4 females.The averages,range of variation and 99% confidence limits are listed in Table Ⅲ.Systematic studies of individual chromosomes under the light microscope revealed the following morphological characteristics.The short arms of all 10 acrocentric chromosomes from groups 13—15 and 21—22 could be shown to possess satellites,but in general only 2—8 of these chromosomes at a time carried satellites.In many cells the satellite-carrying chromosomes tended to associate with each other through their satellites.The number of chromosomes involved in each association varied between 2 to 5,occasionally 6.It was not rare to find secondary constrictions to occur regularly in certain regions of chromosomes 1,4,9,13,and 16.Attachments of satellites to such regions of chromosomes 1,4,9,and 13 were also observed.Karyotypic analysis of 357 metaphase plates led us to conclude that in most cases the unequivocal identification of chromosome pairs 4—5,6—12+X,13—15,19—20,and 21—22 was im- possible.Accurate characterisation of these chromosome pairs will have to await further technical advances. The length of the Y chromosomes was systematically measured in order to deter- mine its variability and heritability.Among our sample of 40 male subjects 29 had a Y chromosome slightly larger than chromosome 21,8 slightly smaller or larger than chromo- some 18(long Y chromosome),and 3 smaller than chromosome 21(short Y chromo- some).The heritability of the size of the Y chromosome was established(Fig.Ⅳ). “Spontaneous”aberrations were discovered in 34 of 70 cases.Aberration rates varied from 0.88 to 13 per cent.The relation between aberrations and radiation injuries was briefly discussed.
