Genome-wide mapping of Painting of fourth on Drosophila melanogaster salivary gland polytene chromosomes

A 75-kilodalton polypeptide has been identified which copurifies with karyoskeletal protein-enriched fractions prepared from Drosophila melanogaster embryos. Results of indirect immunofluorescence experiments suggest that this protein, here designated p75, is primarily associated with puffed regions of larval salivary gland polytene chromosomes. In nonpolytenized Schneider 2 tissue culture cells, p75 appeared to be localized throughout the nuclear interior during interphase. In mitotic cells, p75 was redistributed diffusely. A possible role for karyoskeletal elements in transcriptional regulation is discussed.

Download Full-text

XV.—“Ectopic” Pairing and the Distribution of Heterochromatin in the X-Chromosome of Salivary Gland Nuclei of Drosophila melanogaster

Proceedings of the Royal Society of Edinburgh Section B Biology ◽

10.1017/s0080455x00009711 ◽

1946 ◽

Vol 62 (2) ◽

pp. 114-119 ◽

Cited By ~ 6

Author(s):

B. M. Slizynski

Keyword(s):

Drosophila Melanogaster ◽

Salivary Gland ◽

Nucleic Acid ◽

X Chromosome ◽

Polytene Chromosomes ◽

Ectopic Pairing

The problem to be presented here emerges from the following groups of facts and more or less generally accepted opinions.As heterochromatin we may define those parts of chromosomes which reach maximum nucleic acid charge in mitosis or meiosis in times other than metaphase. In salivary gland chromosomes (which are more conveniently called polytene chromosomes) of Drosophila melanogaster the proximal heterochromatic parts of all chromosomes come together and form a central undifferentiated mass, the chromocentre. Genetically heterochromatin forms the so-called inert regions of the chromosomes.

Download Full-text

The faint band/interband region 28C2 to 28C4-5(−) of the Drosophila melanogaster salivary gland polytene chromosomes is rich in transcripts

MGG Molecular & General Genetics ◽

10.1007/bf00273590 ◽

1991 ◽

Vol 226-226 (1-2) ◽

pp. 81-87 ◽

Cited By ~ 7

Author(s):

Thomas B. Friedman ◽

Kelly N. Owens ◽

Jean B. Burnett ◽

Anja O. Saura ◽

Lori L. Wallrath

Keyword(s):

Drosophila Melanogaster ◽

Salivary Gland ◽

Polytene Chromosomes ◽

Faint Band ◽

Interband Region

Download Full-text

The genetic analysis of puffing in polytene chromosomes of Drosophila

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1970.0052 ◽

1970 ◽

Vol 176 (1044) ◽

pp. 319-327 ◽

Cited By ~ 16

Keyword(s):

Drosophila Melanogaster ◽

Salivary Gland ◽

Genetic Analysis ◽

Structural Gene ◽

Chromosome Aberrations ◽

Polytene Chromosomes ◽

Drosophila Simulans ◽

Salivary Gland Chromosome ◽

Observed Behaviour

The characteristics of several mutants of Drosophila melanogaster and Drosophila simulans lacking particular salivary gland chromosome puffs are described. On the basis of their observed behaviour in heterozygotes these puff mutants can be classified into puff structural gene and puff regulating gene mutants. Other types of mutation affecting the larval and prepupal puffing cycle include lethals, mutants controlling puff size, and chromosome aberrations which divide a puff into two separate puffs.

Download Full-text

p75, a polypeptide component of karyoskeletal protein-enriched fractions associated with transcriptionally active loci of Drosophila melanogaster polytene chromosomes.

Molecular and Cellular Biology ◽

10.1128/mcb.8.5.1877 ◽

1988 ◽

Vol 8 (5) ◽

pp. 1877-1886 ◽

Cited By ~ 3

Author(s):

B M Benton ◽

S Berrios ◽

P A Fisher

Keyword(s):

Tissue Culture ◽

Drosophila Melanogaster ◽

Transcriptional Regulation ◽

Salivary Gland ◽

Indirect Immunofluorescence ◽

Polytene Chromosomes ◽

Nuclear Interior ◽

Culture Cells ◽

Tissue Culture Cells ◽

Larval Salivary Gland

A 75-kilodalton polypeptide has been identified which copurifies with karyoskeletal protein-enriched fractions prepared from Drosophila melanogaster embryos. Results of indirect immunofluorescence experiments suggest that this protein, here designated p75, is primarily associated with puffed regions of larval salivary gland polytene chromosomes. In nonpolytenized Schneider 2 tissue culture cells, p75 appeared to be localized throughout the nuclear interior during interphase. In mitotic cells, p75 was redistributed diffusely. A possible role for karyoskeletal elements in transcriptional regulation is discussed.

Download Full-text

Genes Containing Long Introns Occupy Series of Bands and Interbands in Drosophila melanogaster Polytene Chromosomes

Genes ◽

10.3390/genes11040417 ◽

2020 ◽

Vol 11 (4) ◽

pp. 417

Author(s):

Varvara A. Khoroshko ◽

Galina V. Pokholkova ◽

Victor G. Levitsky ◽

Tatyana Yu. Zykova ◽

Oksana V. Antonenko ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Polytene Chromosomes ◽

Housekeeping Genes ◽

Wide Distribution ◽

Gene Location ◽

Gene Arrangement ◽

Drosophila Genome ◽

Genetic Organization ◽

Genome Wide ◽

Bioinformatic Approaches

The Drosophila melanogaster polytene chromosomes are the best model for studying the genome organization during interphase. Despite of the long-term studies available on genetic organization of polytene chromosome bands and interbands, little is known regarding long gene location on chromosomes. To analyze it, we used bioinformatic approaches and characterized genome-wide distribution of introns in gene bodies and in different chromatin states, and using fluorescent in situ hybridization we juxtaposed them with the chromosome structures. Short introns up to 2 kb in length are located in the bodies of housekeeping genes (grey bands or lazurite chromatin). In the group of 70 longest genes in the Drosophila genome, 95% of total gene length accrues to introns. The mapping of the 15 long genes showed that they could occupy extended sections of polytene chromosomes containing band and interband series, with promoters located in the interband fragments (aquamarine chromatin). Introns (malachite and ruby chromatin) in polytene chromosomes form independent bands, which can contain either both introns and exons or intron material only. Thus, a novel type of the gene arrangement in polytene chromosomes was discovered; peculiarities of such genetic organization are discussed.

Download Full-text

Toroidal bands in polytene chromosomes of Drosophila

Journal of Cell Science ◽

10.1242/jcs.64.1.255 ◽

1983 ◽

Vol 64 (1) ◽

pp. 255-264

Author(s):

V. Sorsa

Keyword(s):

Electron Microscopy ◽

Drosophila Melanogaster ◽

Salivary Gland ◽

Thin Section ◽

Polytene Chromosomes ◽

Thin Sections ◽

Sister Chromatids ◽

Thin Section Electron Microscopy ◽

Section Electron ◽

Section Electron Microscopy

Results obtained from the thin-section electron microscopy of salivary gland chromosomes of Drosophila melanogaster mainly support the concept of cable-like organization of polytene chromosomes, with disk-like bands composed of parallel bundles of homologous chromomeres. Outward orientation of loop fibres may generally cause a toroidal bending in the chromomere bundles. Both longitudinal and transverse sections of polytene chromosomes indicate that the bands may contain toroidal subunits. Torus-shaped bands were only found in thin sections of the most distal and most proximal regions, as well as in certain heavy bands at the late-replicating regions of polytenized interphase chromosomes. This suggests that an incomplete duplication of chromomeres may be a reason for torus formation, by preventing the separation of sister chromatids at the earliest phases of the polytenization process. The appearance of more numerous, but smaller, subunits in thin-sectioned faint bands is interpreted as a consequence of more complete segregation of sister chromatids in those bands during polytenization.

Download Full-text

LARVAL AGE AND THE PATTERN OF DNA SYNTHESIS IN POLYTENE CHROMOSOMES

Canadian Journal of Genetics and Cytology ◽

10.1139/g68-011 ◽

1968 ◽

Vol 10 (1) ◽

pp. 82-90 ◽

Cited By ~ 44

Author(s):

David Nash ◽

John Bell

Keyword(s):

Drosophila Melanogaster ◽

Salivary Gland ◽

Dna Synthesis ◽

Polytene Chromosomes ◽

Larval Life ◽

Gland Cells ◽

Salivary Gland Cells ◽

Puparium Formation ◽

Chromosome Ii ◽

Replicative Cycle

It has been shown, by autoradiography using H3-thymidine, that the frequency of salivary gland cells where DNA synthesis covers the entire length of a specific polytene chromosomal segment (Chromosome II, 56F-60A, Drosophila melanogaster) drops off some time during the last day of larval life. The frequency of highly discontinuous DNA synthesis over the same region remains at about the same level until a stage closer to puparium formation, when all DNA synthesis stops.If a cycle of DNA synthesis, once initiated, goes to completion, then this finding indicates that the patterns of spatially continuous synthesis tend to occur early in the replicative cycle and that the terminal phases of the cycle involve highly discontinuous patterns of synthesis.

Download Full-text