The male karyotypes of Acmaeodera pilosellae persica Mannerheim, 1837 with 2n=20 (18+neoXY), Sphenoptera scovitzii Faldermann, 1835 (2n=38-46), Dicerca aenea validiuscula Semenov, 1895 - 2n=20 (18+Xyp) and Sphaerobothris aghababiani Volkovitsh et Kalashian, 1998 - 2n=16 (14+Xyp) were studied using conventional staining and different chromosome banding techniques: C-banding, AgNOR-banding, as we...

Cytological hybridization combined with microdissection of Chironomus tentans salivary gland cells was used to locate DNA complementary to newly synthesized RNA from chromosomes and nuclear sap and from a single chromosomal puff, the Balbiani ring 2 (BR 2). Salivary glands were incubated with tritiated nucleosides. The labeled RNA was extracted from microdissected nuclei and hybridized to denat...

Cells of the established cell lines of the rat kangaroo (Puotorous tridactylis), were laser microirradiated in order to study their nucleolar organizers. Microbeam irradiation of prophase and metaphase nucleolar organizer sites in both male (PTK 1) and female (PTK2) cells resulted in a reduction in the number of normal nucleoli formed following mitosis. Irradiation of the one nucleolar organize...

ECENT studies of the highly differentiated pachytene chromosomes of R the tomato have indicated that this plant can be used in the analysis of chromosome structure in relation to chromosome behavior and gene location (BROWN 1949; BARTON 1950). In general, the twelve paired chromosomes of the tomato pachytene complement are differentiated into densely staining (chromatic) regions proximally on e...

The genus Astyanax is one of the most numerous of the family Characidae, comprising a large number of similar-shaped species, but displaying innumerable karyotypic variations in its chromosome number and/or structure. The literature describes A. fasciatus populations with diploid chromosome numbers varying from 2n = 45 to 2n = 48. In this study, A. fasciatus specimens captured in the Araguari R...

Quercus petraea and Quercus robur are two closely related oak species that frequently hybridize. We sequenced 70 clones containing the 5.8S and ITS2 regions of ribosomal DNA (rDNA) from these two species and did not detect a species-specific difference. Surprisingly, three divergent (up to 12.6%) rDNA families were identified in both species, indicating that they predate the speciation event. D...

The ultrastructure of embryonic root cells of Zea mays was studied from the quiescent stage (dry seed) to 72 h of germination. Semithin and ultrathin sections of tissues fixed with only glutaraldehyde and embedded in Epon were observed after usual section staining and after cytochemical reactions specific for DNA or preferential for ribonucleoproteiNS. In quiescent cells, dense chromatin forms ...

In this study, the karyotype, C-heterochromatin blocks, and nucleolar organizer regions (NORs) of four specimens of Lepus europaeus from Turkey were examined. The diploid number of chromosomes (2n), the fundamental number of chromosome arms (FN), and the number of autosomal arms (FNa) were determined as 48, 90, and 86, respectively. All of the chromosomes have been determined to be possessed of...