Topic
Polytene chromosome
About: Polytene chromosome is a research topic. Over the lifetime, 2667 publications have been published within this topic receiving 88255 citations.
Papers published on a yearly basis
Papers
More filters
01 Jan 2000
TL;DR: The method described here is a simplified version which additionally allows for the hybridization of more than one DNA probe simultaneously and results in very precise mapping of two neighboring DNA probes, provided that these probes are differentially labeled and therefore can be detected by an-ger colors.
Abstract: Principle and Polytene chromosomes consist of up to several thousands of chromatids applications and are therefore especially suitable for direct mapping with the help ofIn situhybridization. With the introduction of nonradioactive labeling and detection methods, e.g., fluorescenceIn situhybridization (FISH) (Lan-ger-Safer et al., 1982), theIn situhybridization procedure has become easy to perform and the results can be obtained within a day. Furthermore, the method described here (Schmidt et al., 1988; Schmidt, 1992) is a simplified version which additionally allows for the hybridization of more than one DNA probe simultaneously. This double or multicolor hybridization results in very precise mapping of two neighboring DNA probes, provided that these probes are differentially labeled and therefore can be detected by an-ger colors. In this way, it was possible to simultaneously localize two DNA sequences which were only approximately 35 kb apart from each other inChironomus, and less than 20 kb inDrosophila melanogaster(Figure1). Thus, it is easy to determine the orientation of a cloned region of DNA (e.g., a genomic walk) (Kraemer and Schmidt, 1993) and the direction of an-ger of a gene within this region with respect to the centromer and telomer of the chromosome concerned. In addition, multicolor FISH does not only allow for the localization of a DNA probe to a certain an-ger region (or band), but even more precisely with respect to other neighboring DNA probes, which may reside in the same chromosomal band (Kraemer et al., 1998).
TL;DR: The number of ectopic contacts can be differ significantly in independent experiments, possibly indicating the role of random factors in the contact formation and the majority of telomeres in polytene nuclei of salivary glands in Drosophila strain y2-717 is localized in the nuclear central area and have no contacts with nuclear membrane.
Abstract: 3D-FISH method was employed to investigate the telomere topology in polytene nuclei of salivary glands in Drosophila melanogaster. The majority of telomeres in polytene nuclei of salivary glands in Drosophila strain y2-717 is localized in the nuclear central area and have no contacts with nuclear membrane. In the females ectopic contacts between telomeres occur in frequency 25% higher than in males. HeT-A DNA in y2-717alk3-2 strain, which is a derivative of the y2-717 stain carrying an inversion between 1B and 13C bands, is found in the region 13 of X chromosome. The frequency of ectopic contacts of telomeres in y2-717alk3-2 males is 10% higher than in the y2-717 strain. The number of ectopic contacts can be differ significantly in independent experiments, possibly indicating the role of random factors in the contact formation.
TL;DR: Not received Anopheles stephensi Polytene chromosome Puff induction Insecticide; however, research into its application in wound healing and wound protection has shown promising results.
Journal Article•
01 Jan 2004
TL;DR: The study of chromosomes started earlier in the 19th century and Boveri, working with chromosomes of sea urchins in culture, theorized that chromosome changes were the cause of neoplasia.
Abstract: In the Magnificent History of Genetics, written by Dr. Hsu (1), the time before 1952 was characterized as the “Dark Ages” of cytogenetics. Actually, the study of chromosomes started earlier in the 19th century. Walther Flemming discovered lampbrush chromosomes, described them in 1882, and coined the term “mitosis” (2). Balbiani communicated the structure of the polytene chromosomes in 1881 (3). Wilhelm Waldeyer-Artz coined the term “chromosome” in 1888 (4). Using grasshopper testes, Walter Sutton published The Chromosome Theory of Heredity in 1903 (5). Boveri, working with chromosomes of sea urchins in culture, theorized that chromosome changes were the cause of neoplasia (6).