Meiosis aspects and nucleolar activity in Triatoma vitticeps (Triatominae, Heteroptera).
Some aspects of both the nucleolar organizer activity and meiosis were studied in the testes of Triatoma vitticeps (Heteroptera, Triatominae). The techniques used included squashing followed by lacto-acetic orcein staining, silver-ion impregnation, fluorescent banding (CMA3, Quinacrine mustard and DAPI) and fluorescent in situ hybridization (FISH). A close relationship between heterochromatin and nucleolus in testicular cells was observed. During meiosis, the silver-ion impregnation pattern varied. At metaphase plate, a small body appeared apart from the chromosomes. In the spermatids this small body was seen in preparations stained with orcein and silver- ion impregnation but not with fluorochromes or FISH. These characteristics combined suggest that these corpuscles represent a source of ribonucleoproteins (RNP)-RNA and specific nucleolar proteins. Silver-ion impregnation and (FISH) revealed nucleolar organizer activity in two metaphase sex chromosomes (X). These results indicate that, in these species, nucleolar organizer regions (NORs) are located in the sex chromosomes, X chromosomes were CMA3+ and Y chromosome was DAPI+.
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Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, IBILCE-UNESP, Rua Cristóvão Colombo n, 2265, Caixa Postal 136, São José do Rio Preto, CEP 15054-000, São Paulo, Brazil. grazielaguiar@terra.com.br
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D000818:Animals; D002466:Cell Nucleolus / Q000235:genetics*; D002871:Chromosome Banding; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008540:Meiosis / Q000235:genetics*; D010078:Oxazines; D013091:Spermatogenesis / Q000235:genetics*; D013194:Staining and Labeling; D013737:Testis / Q000378:metabolism; D014224:Triatoma / Q000235:genetics*
D010078:Oxazines; C002313:PAcein