dMi-2 is a highly conserved ATP-dependent chromatin-remodeling factor that regulates transcription and cell fates by altering the structure or positioning of nucleosomes. Here we report an unanticipated role for dMi-2 in the regulation of higher-order chromatin structure in Drosophila. Loss of dMi-2 function causes salivary gland polytene chromosomes to lose their characteristic banding pattern...

In the 1960s Letha Karunakaran studied chironomid fauna of Singapore but faced a lack sufficiently detailed descriptions to enable identification her material with any certainty. She recognized seven species Chironomus (s.s) sent me fixed larval only four these which she tentatively identified as C. apicatus Johannsen 1932, costatus javanus Kieffer 1924, and stupidus 1932. larvae for confirmati...

In situ hybridization techniques, along with immunocytochemistry allow detection of specific DNA or RNA sequences or proteins in morphologically preserved chromosomes, cells or tissue sections. This technique was originally developed by two independent groups, Pardue and Gall (1969) and John et al. (1969). Since then it has been modified and refined for different applications. Conventional in s...

The paper provides a short review of blackfly cytogenetics. The most important characters of blackfly karyotypes, such as centromeres, puffs, Balbiani rings, nucleoli, sex-chromosome determining systems and B-chromosomes are considered. Interchromosomal homozygous translocations and a tandem fusion of polytene chromosomes are described. Evolutionary trends in karyotypic changes are discussed.

Dipteran polytene chromosomes provide an excellent model for understanding in species complexes, as well as for structural and functional cytogenetics. The status of species in the Culex pipiens complex is controversial and the use of polytene chromosomes for cytogenetic analysis in the subfamily Culicinae has been difficult because of methodological problems. In this study, Malpighian tubule p...

Genetic and cytogenetic studies constitute a significant basis for understanding the biology of insect pests and the design and the construction of genetic tools for biological control strategies. Anastrepha fraterculus is an important pest of the Tephritidae family. It is distributed from southern Texas through eastern Mexico, Central America and South America causing significant crop damage a...

Previous investigations on the effects of monovalent cations on the gene activities (formation of puffs) of polytene chromosomes utilized whole salivary glands or nuclei and suggested that the K/Na ratio in the nuclear sap was of primary importance in influencing gene activities. To determine whether these effects of ions were direct or indirect, we have employed isolated polytene chromosomes i...

In situ hybridization to Drosophila polytene chromosomes is a powerful tool for determining the chromosomal location of genes. Using in situ hybridization experiments, Yi and Charlesworth recently reported the transposition of the exuperantia1 gene (exu1) from a neo-sex chromosome to the ancestral X chromosome of Drosophila miranda, close to exuperantia2 (exu2). By characterizing sequences flan...

Anopheles culicifacies sensu lato collected from Rameshwaram island, Tamil Nadu state, India was identified as species B based on the diagnostic inversion karyotype Xab 2g1+h1 as observed in polytene chromosomes. Among male mitotic karyotypes made from larval neurogonial cells, two types were observed: one with an acrocentric Y-chromosome and the other with a sub-metacentric Y-chromosome, both ...