Polyteny

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Polyteny

the presence in the nucleus of certain somatic cells of giant multifilamentous (polytene) chromosomes, which are hundreds of times larger than normal chromosomes. Polyteny leads to substantial increase in ploidy of the nuclei (up to 32.768N in Chironomus). Polyteny was first described in 1881 by the French cytologist E. Balbiani. Polytene chromosomes are observed in the cells of larvae of a number of Diptera (Chironomus, Drosophila), in Protozoa, and in some plant cells. Polyteny is the result of repeated replications of chromosomes without subsequent divsion of the cell or its nucleus. Giant chromosomes are characterized by specificity of location of the cross-bands, which permits compilation of chromosome maps and study of the functional activities of each band or group of bands.

REFERENCES

Lobashev, M. E. Genetika, 2nd ed. Leningrad, 1967. Swanson, C, T. Merz, and W. Young. Tsitogenetika. Moscow, 1969. (Translated from English.)

M. M. ASLANIAN

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No references found			Endopolyploidy and polyteny in differentiation's and evolutions. The problem of giant cells in biology by Nanushyan, E.R.; Skripnikov, A.Y.; Murashov, V.V. / Frontier Perspectives			Polyspermy polyspore polystele Polystichum Polystomatoidea polystyle Polystylifera Polystyrene polystyrene capacitor polystyrene dielectric polystyrene foam polystyrene resin Polysulfide Polysulfide Rubber polysulfide treating polysulfone resin Polysyllogism Polysyndeton Polysynthetic Language polysynthetic twinning polytechnic Polytechnical Education Polytechnical Institutes Polytechnical Museum polytene chromosome Polyteny polyterpene resin polytetrafluoroethylene Polytheism Polythematic Music polythene Polytonality Polytonic Stress Polytope Polytrichales Polytrichum polytrifluorochloroethylene resin Polytropic Atmosphere polytropic compression curve Polytropic Curve Polytropic Process polytype polytypic polytypism polyunsaturated polyunsaturated acid polyunsaturated fat Polyurea Polyurethan Polyurethan Adhesive Polyurethan Varnish			Polytechnic Research and Development Company Polytechnic Teachers' Association of Ghana Polytechnic University of Puerto Rico Polytechnic University of the Philippines Polytechnic University of the Philippines - College of Communication Polytechnical Polytechnical Polytechnical Education Polytechnical Institutes Polytechnical Museum Polytechnics Polytechnics Polytechnics and Colleges Funding Council Polytechnics Central Admissions System Polytechnics International New Zealand Limited Polytechnische Oberschule polytef polytef polytef Polyteknikkojen Radiokerho polytendinitis polytene polytene polytene Polytene chromosome Polytene chromosome Polytene chromosome polytenic polytenic polytenosynovitis Polyteny polyterpene resin Polyterpenoid Polyterpenoid Polyterpenoid Polytetra Methylene Terephthalate Polytetracfluoroethane Polytetracfluoroethane Polytetracfluoroethane Polytetraflouroethylene Polytetraflouroethylene Polytetraflouroethylene Polytetrafluorethylene Polytetrafluorethylene Polytetrafluorethylene Polytetrafluorethylene Polytetrafluoroethene Polytetrafluoroethene Polytetrafluoroethene polytetrafluoroethylene polytetrafluoroethylene polytetrafluoroethylene polytetrafluoroethylene Polytetrafluroethylene Polytetrafluroethylene Polytetrafluroethylene Polytetrahydrofuran Polytetramethylene Glycol Polytetramethyleneetherglycol Polythalamia Polythalamous

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