The genes for ribosomal RNA in diploid and polytene chromosomes of Drosophila melanogaster

Chromosoma ◽  
1974 ◽  
Vol 48 (2) ◽  
Author(s):  
BrianB. Spear
1977 ◽  
Vol 115 (3) ◽  
pp. 539-563 ◽  
Author(s):  
Paul Szabo ◽  
Robert Elder ◽  
Dale M. Steffensen ◽  
Olke C. Uhlenbeck

Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 197-204
Author(s):  
Christine Hoogland ◽  
Christian Biémont

Abstract Data of insertion site localization and site occupancy frequency of P, hobo, I, copia, mdg1, mdg3, 412, 297, and roo transposable elements (TEs) on the polytene chromosomes of Drosophila melanogaster were extracted from the literature. We show that TE insertion site number per chromosomal division was significantly correlated with the amount of DNA. The insertion site number weighted by DNA content was not correlated with recombination rate for all TEs except hobo, for which a positive correlation was detected. No global tendency emerged in the relationship between TE site occupancy frequency, weighted by DNA content, and recombination rate; a strong negative correlation was, however, found for the 3L arm. A possible dominant deleterious effect of chromosomal rearrangements due to recombination between TE insertions is thus not the main factor explaining the dynamics of TEs, since this hypothesis implies a negative relationship between recombination rate and both TE insertion site number and site occupancy frequency. The alternative hypothesis of selection against deleterious effects of insertional mutations is discussed.


Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 617-624 ◽  
Author(s):  
S M Williams ◽  
J A Kennison ◽  
L G Robbins ◽  
C Strobeck

Abstract The role of reciprocal recombination in the coevolution of the ribosomal RNA gene family on the X and Y chromosomes of Drosophila melanogaster was assessed by determining the frequency and nature of such exchange. In order to detect exchange events within the ribosomal RNA gene family, both flanking markers and restriction fragment length polymorphisms within the tandemly repeated gene family were used. The vast majority of crossovers between flanking markers were within the ribosomal RNA gene region, indicating that this region is a hotspot for heterochromatic recombination. The frequency of crossovers within the ribosomal RNA gene region was approximately 10(-4) in both X/X and X/Y individuals. In conjunction with published X chromosome-specific and Y chromosome-specific sequences and restriction patterns, the data indicate that reciprocal recombination alone cannot be responsible for the observed variation in natural populations.


Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 429-434
Author(s):  
J James Donady ◽  
R L Seecof ◽  
M A Fox

ABSTRACT Drosophila melanogaster embryos that lacked ribosomal DNA were obtained from appropriate crosses. Cells were taken from such embryos before overt differentiation took place and were cultured in vitro. These cells differentiated into neurons and myocytes with the same success as did wild-type controls. Therefore, ribosomal RNA synthesis is not necessary for the differentiation of neurons and myocytes in vitro.


Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Leonard G Robbins

Abstract Rex is a multicopy genetic element that maps within an X-linked ribosomal RNA gene (rDNA) array of D. melanogaster. Acting maternally, Rex causes recombination between rDNA arrays in a few percent of early embryos. With target chromosomes that contain two rDNA arrays, the exchanges either delete all of the material between the two arrays or invert the entire intervening chromosomal segment. About a third of the embryos produced by Rex homozygotes have cytologically visible chromosome damage, nearly always involving a single chromosome. Most of these embryos die during early development, displaying a characteristic apoptosis-like phenotype. An experiment that tests whether the cytologically visible damage is rDNA-specific is reported here. In this experiment, females heterozygous for Rex and an rDNA-deficient X chromosome were crossed to males of two genotypes. Some of the progeny from the experimental cross entirely lacked rDNA, while all of the progeny from the control cross had at least one rDNA array. A significantly lower frequency of early-lethal embryos in the experimental cross, proportionate to the fraction of rDNA-deficient embryos, demonstrates that Rex preferentially damages rDNA.


Chromosoma ◽  
1981 ◽  
Vol 82 (2) ◽  
pp. 205-216 ◽  
Author(s):  
F. Scalenghe ◽  
E. Turco ◽  
J. E. Edström ◽  
V. Pirrotta ◽  
M. Melli

1974 ◽  
Vol 141 (3) ◽  
pp. 609-615 ◽  
Author(s):  
John Shine ◽  
Lynn Dalgarno

The 3′-terminal sequence of 18S ribosomal RNA from Drosophila melanogaster and Saccharomyces cerevisiae was determined by stepwise degradation from the 3′-terminus and labelling with [3H]isoniazid. The sequence G-A-U-C-A-U-U-AOH was found at the 3′-terminus of both 18S rRNA species. Less extensive data for 18S RNA from a number of other eukaryotes are consistent with the same 3′-terminal sequence, and an identical sequence has previously been reported for the 3′-end of rabbit reticulocyte 18S rRNA (Hunt, 1970). These results suggest that the base sequence in this region is strongly conserved and may be identical in all eukaryotes. As the 3′-terminal hexanucleotide is complementary to eukaryotic terminator codons we discuss the possibility that the 3′-end of 18S rRNA may have a direct base-pairing role in the termination of protein synthesis.


1993 ◽  
Vol 104 (4) ◽  
pp. 1263-1272 ◽  
Author(s):  
C.A. Bossie ◽  
M.M. Sanders

A novel intermediate filament cDNA, pG-IF, has been isolated from a Drosophila melanogaster embryonic expression library screened with a polyclonal antiserum produced against a 46 kDa cytoskeletal protein isolated from Kc cells. This 46 kDa protein is known to be immunologically related to vertebrate intermediate filament proteins. The screen resulted in the isolation of four different cDNA groups. Of these, one has been identified as the previously characterized Drosophila nuclear lamin cDNA, Dm0, and a second, pG-IF, demonstrates homology to Dm0 by cross hybridization on Southern blots. DNA sequence analysis reveals that pG-IF encodes a newly identified intermediate filament protein in Drosophila. Its nucleotide sequence is highly homologous to nuclear lamins with lower homology to cytoplasmic intermediate filament proteins. pG-IF predicts a protein of 621 amino acids with a predicted molecular mass of 69,855 daltons. In vitro transcription and translation of pG-IF yielded a protein with a SDS-PAGE estimated molecular weight of approximately 70 kDa. It contains sequence principles characteristic of class V intermediate filament proteins. Its near neutral pI (6.83) and the lack of a terminal CaaX motif suggests that it may represent a lamin C subtype in Drosophila. In situ hybridization to polytene chromosomes detects one band of hybridization on the right arm of chromosome 2 at or near 51A. This in conjunction with Southern blot analysis of various genomic digests suggests one or more closely placed genes while Northern blot analysis detects two messages in Kc cells.


1980 ◽  
Vol 87 (2) ◽  
pp. 415-419 ◽  
Author(s):  
J Cavagnaro ◽  
D A Pierce ◽  
J C Lucchesi ◽  
C B Chae

Incubation of Drosophila salivary glands with radioactive diisopropyl fluorophosphate results in the uniform labeling of polytene chromosomes. Extensive labeling is seen only when chromosome squashes are prepared by a formaldehyde fixation procedure and not by standard acetic acid techniques. The labeling is inhibited in the presence of tosylphenylalanine chloromethyl ketone and phenylmethane sulfonylfluoride but not by tosyllysine chloromethyl ketone, suggesting that a chymotrypsin-like serine protease is associated with the chromosomes. Protease inhibitors show no apparent effect on heat-shock specific puffing.


Genome ◽  
1994 ◽  
Vol 37 (6) ◽  
pp. 1018-1021 ◽  
Author(s):  
M. Nenno ◽  
K. Schumann ◽  
W. Nagl

This is the first report of fluorescence in situ hybridization (FISH) on plant polytene chromosomes. Different protease pretreatments have been tested to improve fluorescence in situ hybridization FISH on polytene chromosomes of a plant, Phaseolus coccineus, with the aim to enable the detection of low-copy genes. The structural preservation of the chromosomes and the distinctness of the FISH signals were comparatively analysed with a probe for the ribosomal RNA genes after digestion with pepsin and trypsin. The pepsin pretreatment resulted in a general loosening of chromatin with good conservation of chromosome morphology and an increased number and density of signal points. The six nucleolus organizers exhibited significant differences in condensation. The pretreatment with pepsin enabled the detection of the low-copy genes encoding the seed storage protein phaseolin.Key words: plant, Leguminosae, ribosomal RNA genes, seed storage protein genes, protease.


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