title: X-linked heterochromatin distribution in the holocentric chromosomes of the green apple aphid Aphis pomi.
abstract: Chromatin organization in the holocentric chromosomes of the green apple aphid Aphis pomi has been investigated at a cytological level after C-banding, NOR, Giemsa, fluorochrome staining and fluorescent in situ hybridization (FISH). C-banding technique showed that heterochromatic bands are exclusively located on X chromosomes. This data represents a peculiar feature that clearly contradicts the equilocal distribution of heterochromatin typical of monocentric chromosomes. Moreover, silver staining and FISH carried out with a 28S rDNA probe localized rDNA genes on one telomere of each X chromosome; CMA3 staining reveals that these silver positive telomeres are the only GC-rich regions among A. pomi heterochromatin, whereas all other C-positive bands are DAPI positive thus containing AT-rich DNA.
authors: Dipartimento di Scienze Agrarie, Università di Modena e Reggio Emilia, Reggio Emilia, Italia.
authors: A
authors: A
authors: Criniti
authors: G
authors: G
authors: Simonazzi
authors: S
authors: S
authors: Cassanelli
authors: M
authors: M
authors: Ferrari
authors: D
authors: D
authors: Bizzaro
authors: G C
authors: GC
authors: Manicardi
mesh_terms: D000818:Animals; D001042:Aphids / Q000235:genetics*; D004275:DNA, Ribosomal / Q000032:analysis; D005260:Female; D006570:Heterochromatin / Q000737:chemistry*; D017404:In Situ Hybridization, Fluorescence; D014960:X Chromosome / Q000737:chemistry
chemical_list: D004275:DNA, Ribosomal; D006570:Heterochromatin