C banding in polytene chromosomes of Chironomus riparius from a Santena polluted station of the river Po, Italy was described. A large variation in the appearance of C bands was established. The process involved the transformation of euchromatin into heterochromatin. Activation of all chromosomes at telomeres was found. A structural modification of telomeric heterochromatin may exist. The centromeric heterochromatin was rarely observed. A high percentage of an amplification (88%) in arm F, B3h, was recorded. These changes in the appearance of heterochromatin in the population studied could be considered as a type of polymorphic system, existing in the polluted population. For the first time in C. riparius two types of position effect variegation are reported. In arm E the euchromatin near to the centromere became inactive due to a heterozygous inversion and in arms D and F the opposite phenomenon was observed in which a heterozygous inversion partly suppressed the inactivation of heterochromatin.

C band variation in polytene chromosomes of Chironomus riparius (diptera, chironomidae) from a polluted Piedmont station (Italy)

RAMELLA GAL, Liliana;SELLA, Gabriella;
1997-01-01

Abstract

C banding in polytene chromosomes of Chironomus riparius from a Santena polluted station of the river Po, Italy was described. A large variation in the appearance of C bands was established. The process involved the transformation of euchromatin into heterochromatin. Activation of all chromosomes at telomeres was found. A structural modification of telomeric heterochromatin may exist. The centromeric heterochromatin was rarely observed. A high percentage of an amplification (88%) in arm F, B3h, was recorded. These changes in the appearance of heterochromatin in the population studied could be considered as a type of polymorphic system, existing in the polluted population. For the first time in C. riparius two types of position effect variegation are reported. In arm E the euchromatin near to the centromere became inactive due to a heterozygous inversion and in arms D and F the opposite phenomenon was observed in which a heterozygous inversion partly suppressed the inactivation of heterochromatin.
1996
139
151
http://www.scopus.com/inward/record.url?eid=2-s2.0-0031307041&partnerID=40&md5=272f7cf93a711b0b7963b7a32645c7ab
heavy metal; animal, article, Chironomidae, chromosome, chromosome banding pattern, chromosome inversion, drug effect, gene expression regulation, genetics, growth; development and aging, heterochromatin, Italy, soil pollutant, telomere, ultrastructure; Animals, Chironomidae, Chromosome Banding, Chromosomes, Gene Expression Regulation, Heterochromatin, Inversion; Chromosome, Italy, Metals; Heavy, Soil Pollutants, Telomere
P. Michailova;L. Ramella;G. Sella;S. Bovero
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/139824
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