polytene chromosome


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Related to polytene chromosome: lampbrush chromosome

pol·y·tene chro·mo·some

a stage of chromosome division that forms the giant chromosome found in the salivary gland of dipterous insects; the great width is the result of repeated divisions of the chromonema without subsequent lengthwise separation of the filaments.
Synonym(s): giant chromosome (1)

polytene chromosome

[pol′itēn]
Etymology: Gk, polys + tainia, band
an excessively large type of chromosome consisting of a large number of copies of the chromosome bundled side by side. Polytene chromosomes are produced by repeated rounds of DNA synthesis without mitosis and are bundles of unseparated chromonemata filaments found primarily in the salivary glands of certain insects. See also giant chromosome.

polytene chromosome

see SALIVARY GLAND CHROMOSOME.
References in periodicals archive ?
Joe River and since the quality of their polytene chromosomes was excellent, I compared chromosome diversity within and among samples taken in 2011, 2012 and 2013 (avg.
Four polytene chromosomes A1, A2, X1 and X2 were easily recognized in M.
Even though the karyotypes of these species were similar, the study of the puffing activities of polytene chromosomes revealed para- and pericentric inversions, enabling the establishment of their phylogeny (Ashburner and Lemeunier 1972).
We used conventional methods of collection (Shields and Procunier, 1982) and identification of larvae (Currie, 1986), the Feulgen method of Rothfels and Dunbar (1953) to stain polytene chromosomes and gonads of larvae and the standard chromosome maps for the Simulium arcticum complex (Shields and Procunier, 1982) to determine chromosomal variation.
Polytene chromosomes have been basic tools for interpreting chromosomal evolution in anopheline mosquitoes and other insects (simulids, chironomids, drosophilids).
Polytene chromosomes of Orthopodomyia pulcripalpis (Diptera, Culicidae).
Out of Texas, thanks to Theophilus Painter, came the discovery of the giant polytene chromosomes in the larval salivary glands, from which grew a huge field of research in population genetics, owing to the fact that about half of all species of Drosophila have polymorphic inversions in at least one chromosome.
Its chromosomal phylogeny has been established by comparing the banding patterns of the various species and also by the observation of the polytene chromosomes in many interspecific hybrids (Ruiz and Wasserman 1993).
Almost 60 years have elapsed since the discovery of variation in the polytene chromosomes of Drosophila (Sturtevant and Dobzhansky 1936).
The polytene chromosomes of third instar larvae were stained and squashed in lacto-aceto-orcein solution.