Mosaic pattern of X-chromosomal transcription in a strain of Drosophila melanogaster with aneuploid X chromosome.
Indian J Exp Biol
;
1990 Feb; 28(2): 101-5
Article
in English
| IMSEAR
| ID: sea-59423
ABSTRACT
Organisation and template activity pattern of salivary gland chromosomes of a segmental male aneuploid of D. melanogaster, carrying duplication for the segment 8C-20F of X chromosome, have been examined by in situ transcription. In an earlier study [Chatterjee, Chromosoma 91 (1985) 259], it was suggested that in male aneuploids, up to an additional length of 8C-20F, the template activity of X chromosome tends to remain at a male level and beyond that level shifts towards female level. A large scale search of the template activity pattern of the aneuploid carrying dp.(8C-20F) clearly indicates that presence of the duplication fragment to X in the normal karyotype (1X2A) lead to a varying degree of condensation of euchromatic regions of entire X chromosome (X + X fragment 8C-20F) starting from 'male' level, over a wide range of 'intermediate' level to a normal 'female' level. In this study, the individual cells of the aneuploid appeared to display their own state of X condensation and transcription. Although in the aneuploid, X chromosomal activity is not determined by a purely quantitative effect of X vs. autosomal material (XA ratio = 0.81), the 8C-20F segment of X chromosome must contain some major elements concerned with the signal given by XA ratio for X chromosome differentiation.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Transcription, Genetic
/
X Chromosome
/
Female
/
Male
/
Drosophila melanogaster
/
Aneuploidy
/
Animals
/
Mosaicism
Language:
English
Journal:
Indian J Exp Biol
Year:
1990
Type:
Article
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