Molecular and cytogenetic analysis of the heterochromatin-euchromatin junction region of the Drosophila melanogaster X chromosome using cloned DNA sequences - PubMed (original) (raw)

Molecular and cytogenetic analysis of the heterochromatin-euchromatin junction region of the Drosophila melanogaster X chromosome using cloned DNA sequences

M T Yamamoto et al. Genetics. 1990 Aug.

Abstract

We have used three cloned DNA sequences consisting of (1) part of the suppressor of forked transcription unit, (2) a cloned 359-bp satellite, and (3), a type I ribosomal insertion, to examine the structure of the base of the X chromosome of Drosophila melanogaster where different chromatin types are found in juxtaposition. A DNA probe from the suppressor of forked locus hybridizes exclusively to the very proximal polytenized part of division 20, which forms part of the beta-heterochromatin of the chromocenter. The cloned 359-bp satellite sequence, which derives from the proximal mitotic heterochromatin between the centromere and the ribosomal genes, hybridizes to the under replicated alpha-heterochromatin of the chromocenter. The type I insertion sequence, which has major locations in the ribosomal genes and in the distal mitotic heterochromatin of the X chromosome, hybridizes as expected to the nucleolus but does not hybridize to the beta-heterochromatic division 20 of the polytene X chromosome. Our molecular data reveal that the suppressor of forked locus, which on cytogenetic grounds is the most proximal ordinary gene on the X chromosome, is very close to the junction of the polytenized and non-polytenized region of the X chromosome. The data have implications for the structure of beta-heterochromatin-alpha-heterochromatin junction zones in both mitotic and polytene chromosomes, and are discussed with reference to models of chromosome structure.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Proc Natl Acad Sci U S A. 1982 Jan;79(2):564-8 - PubMed
    1. Nucleic Acids Res. 1987 Dec 10;15(23):10061 - PubMed
    1. Annu Rev Genet. 1980;14:121-44 - PubMed
    1. Cell. 1980 Jan;19(1):103-19 - PubMed
    1. Genetics. 1989 Feb;121(2):313-31 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources