title: Molecular and genetic organization of Drosophila melanogaster polytene chromosomes: evidence for two types of interband regions.
abstract: The 3A and 60E regions of Drosophila melanogaster polytene chromosomes containing inserted copies of the P[1ArB] transposon have been subjected to an electron microscopic (EM) analysis. We show that both inserts led to formation of new bands within the interband regions 3A4/A6 and 60E8-9/E10. This allowed us to clone DNA of these interbands. Their sequences, as well as those of DNA from other four interbands described earlier, have been analyzed. We have found that, with the exception of 60E8-9/E10 interband, all other five regions under study corresponded to 5' or 3' ends of genes. We have further obtained the evidence for 60E8-9/E10 interband to harbor the 'housekeeping' RpL19 gene, which is transcribed in many tissues, including salivary glands. Based upon the genetic heterogeneity of the interbands observed a revised model of polytene chromosome organization is discussed.
authors.affiliation: Institute of Cytology and Genetics, 630090 Novosibirsk, Russia.
authors.forename: Sergei
authors.initials: S
authors.lastname: Demakov
authors.forename: Andrei
authors.initials: A
authors.lastname: Gortchakov
authors.forename: Yuri
authors.initials: Y
authors.lastname: Schwartz
authors.forename: Valery
authors.initials: V
authors.lastname: Semeshin
authors.forename: Sonsoles
authors.initials: S
authors.lastname: Campuzano
authors.forename: Juan
authors.initials: J
authors.lastname: Modolell
authors.forename: Igor
authors.initials: I
authors.lastname: Zhimulev
mesh_terms: D000818:Animals; D002871:Chromosome Banding; D002875:Chromosomes / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D008854:Microscopy, Electron; D017422:Sequence Analysis, DNA
chemical_list: D004251:DNA Transposable Elements