the anopheles stephensi mysorensis originating from kazeroon area south of iran, which had been maintained at the laboratory conditions of at 70% relative humidity for almost 150 generations, were subjected to cytogenetical analyses. the ‘instant’ landmarks in the squash preparations of the salivary gland chromosomes are indicative of cytotaxonomic characteristics of the species. the characteri...

The present study constitutes a first attempt to identify the larval salivary gland polytene chromosome arms of Bactrocera papayae Drew & Hancock. This species belongs to the family Tephritidae and is commonly known as the Asian papaya fruit fly. A photographic representation of the polytene chromosomes of this species is provided and the identifying tips as well as most prominent landmarks of ...

Duplicating chromosomes once each cell cycle produces sister chromatid pairs, which separate accurately at anaphase. In contrast, reduplicating chromosomes without separation frequently produces polytene chromosomes, a barrier to accurate mitosis. Chromosome reduplication occurs in many contexts, including: polytene tissue development, polytene tumors, and following treatment with mitosis-block...

Wereport here a cytogenetic analysis of themelonßy,Bactrocera cucurbitae, Coquillett (Diptera: Tephritidae), a species of signiÞcant agricultural importance. The mitotic karyotype and detailed photographic maps of the larval salivary gland polytene chromosomes of the species are presented. The mitotic karyotype consists of six pairs of chromosomes including one pair of heteromorphic sex (XX/XY)...

A study on the polytene chromosomes obtained from the salivary gland cells of Chironomus striatipennis Kieffer indicated that a polytene chromosome is not a typical ribbon like body formed of a number of thread like chromatin elements aligned side by side having condensed chromatin thread at locations forming bands, simple linear threads of chromatin as interbands and highly extended chromatin ...

Using both heterologous rabbit antisera and mouse monoclonal antibody to RNA.DNA hybrids, we have mapped the in situ hybridization locus of the 18/28S ribosomal RNA fraction to a single large band on polytene autosome 3 in Drosophila heteroneura and Drosophila silvestris. This portion of the chromosome is not physically connected with the nucleolus at the end of larval salivary gland developmen...

In this study the effects of AFB1, a mold metabolite, on third instar larval salivary gland polytene chromosomes of Drosophila melanogaster were investigated. The various chromosomal abnormalities (= aberrations) as fragment loss from teminal, semibreak, asynapsis, regional shrinking, ectopic pairing on arms of polytene chromosome, were observed in polytene chromosome slides from third instar l...

Polytene chromosomes exhibit intricate higher order chromatin structure that is easily visualized due to their precisely aligned component strands. However, it remains unclear if the same factors determine chromatin organization in polyploid and diploid cells. We have analyzed one such factor, the cell cycle, by studying changes in Drosophila nurse cell chromosomes throughout the 10 to 12 endoc...

In the fruitfly Drosophila melanogaster, the four male specific lethal (msl) genes are required to achieve dosage compensation of the male X chromosome. The MSL proteins are thought to interact with cis-acting sites that confer dosage compensation to nearby genes, as they are detected at hundreds of discrete sites along the length of the polytene X chromosome in males but not in females. The hi...