Open AccessCytogenetic Analysis of the Holocentric Chromosomes of the Aphid Schizaphis Graminum
Author(s) -
Mandrioli M.,
Ganassi S.,
Bizzaro D.,
Manicardi G. C.
Publication year - 1999
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1999.t01-1-00185.x
Subject(s) - biology , heterochromatin , karyotype , autosome , chromosome , staining , metaphase , dapi , aphid , genetics , fluorescence in situ hybridization , g banding , giemsa stain , microbiology and biotechnology , botany , gene
Chromatin organization in the holocentric chromosomes of the aphid Schizaphis graminum has been investigated at a cytological level after C‐banding, NOR, Giemsa, DAPI and CMA 3 staining. C‐banding technique showed the presence of numerous C bands on the two X chromosomes both in telomeric and intercalary regions, whereas autosomes show a small number of heterochromatic bands. Contrary to the results with other aphid species, in S. graminum the C‐banding pattern is peculiar to each chromosome pair, thus allowing the identification of homologues and the reliable reconstruction of a karyotype. These Cytogenetic data could be useful for the identification of chromosomal rearrangement eventually occurred between different S. graminum biotypes. Moreover, silver staining and fluorescent in situ hybridization (FISH) with a 28S rDNA probe localized rDNA genes on one telomere of each X chromosome; these are the only brightly fluorescent C‐positive regions revealed after CMA 3 staining, whereas all other heterochromatic bands are DAPI positive.