Microsurgical Isolation of Native Polytene Chromosomes of Drosophila melanogaster for In Situ Molecular Observation

SummaryData were collected on the distribution of nine families of transposable elements among second and third chromosomes isolated from a natural population of Drosophila melanogaster, by means of in situ hybridization of element probes to polytene chromosomes. It was found that the copy numbers per chromosome in the distal sections of the chromosome arms followed a Poisson distribution. Elements appeared to be distributed randomly along the distal sections of the chromosome arms. There was no evidence for linkage disequilibrium in the distal sections of the chromosomes, but some significant disequilibrium was detected in proximal regions. There were many significant correlations between different element families with respect to the identity of the sites that were occupied in the sample. There were also significant correlations between families with respect to sites at which elements achieved relatively high frequencies. Element frequencies per chromosome band were generally low in the distal sections, but were higher proximally. These results are discussed in the light of models of the population dynamics of transposable elements. It is concluded that they provide strong evidence for the operation of a force or forces opposing transpositional increase in copy number. The data suggest that the rate of transposition perelement per generation is of the order of 10−4, for the elements included in this study.

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Rates of movement of transposable elements on the second chromosome of Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672399004474 ◽

2000 ◽

Vol 75 (3) ◽

pp. 275-284 ◽

Cited By ~ 43

Author(s):

XULIO MASIDE ◽

STAVROULA ASSIMACOPOULOS ◽

BRIAN CHARLESWORTH

Keyword(s):

Drosophila Melanogaster ◽

Transposable Elements ◽

Polytene Chromosomes ◽

Mutation Accumulation ◽

Long Terminal Repeats ◽

Significant Difference ◽

Transposable Element Copy ◽

Excision Rate

The rates of movement of 11 families of transposable elements of Drosophila melanogaster were studied by means of in situ hybridization of probes to polytene chromosomes of larvae from a long-term mutation accumulation experiment. Replicate mutation-accumulation lines carrying second chromosomes derived from a single common ancestral chromosome were maintained by backcrosses of single males heterozygous for a balancer chromosome and a wild-type chromosome, and were scored after 116 generations. Twenty-seven transpositions and 1 excision were detected using homozygous viable and fertile second chromosomes, for a total of 235056 potential sources of transposition events and a potential 252880 excision events. The overall transposition rate per element per generation was 1·15×10−4 and the excision rate was 3·95×10−6. The single excision (of a roo element) was due to recombination between the element's long terminal repeats. A survey of the five most active elements among nine homozygous lethal lines revealed no significant difference in the estimates of transposition and excision rates from those from viable lines. The excess of transposition over excision events is in agreement with the results of other in situ hybridization experiments, and supports the conclusion that replicative increase in transposable element copy number is opposed by selection. These conclusions are compared with those from other studies, and with the conclusions from population surveys of element frequencies.

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Sequences isolated from a Drosophila early-ecdysone puff are expressed in rat liver

Bioscience Reports ◽

10.1007/bf01122503 ◽

1984 ◽

Vol 4 (5) ◽

pp. 387-396 ◽

Cited By ~ 4

Author(s):

Carmen Arribas ◽

Marta Izquierdo

Keyword(s):

Drosophila Melanogaster ◽

Rat Liver ◽

Recombinant Dna ◽

Polytene Chromosomes ◽

Mammary Glands ◽

Nucleic Acid Hybridization ◽

Adult Rat ◽

Dna And Rna ◽

Polyadenylated Rna

We have studied the presence of a cloned fragment of DNA from Drosophila melanogaster in other organisms by means of nucleic acid hybridization analysis. The isolated region is localized in polytene chromosomes at the 63F subdivision. This region includes a puff that responds within minutes to ecdysone stimulation. We have found that 63F DNA from D. melanogaster hybridizes ‘in situ’ to both DNA and RNA from D. simulans, D. teissieri, and D. hydei. In all these species the isolated DNA remains associated with one early-ecdysone stimulated puff. The isolated Drosophila recombinant DNA is also complementary to polyadenylated RNA from foetal and adult rat liver but fails to hybridize to the nonpolyadenylated RNA classes from both sources and to polyadenylated RNA from rat mammary glands.

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Chromosomal localization of the white gene of Lucilia cuprina (Diptera; Calliphoridae) by in situ hybridization

Genome ◽

10.1139/g87-012 ◽

1987 ◽

Vol 29 (1) ◽

pp. 72-75 ◽

Cited By ~ 10

Author(s):

D. G. Bedo ◽

A. J. Howells

Keyword(s):

Drosophila Melanogaster ◽

In Situ Hybridization ◽

Key Words ◽

Chromosomal Localization ◽

Polytene Chromosomes ◽

White Gene ◽

Lucilia Cuprina ◽

Standard Methods ◽

Cytological Data

The white gene of Lucilia cuprina was mapped to trichogen polytene chromosomes using in situ hybridization. A tritium-labelled riboprobe made from the first gene cloned from this species was used with techniques modified from standard methods used for Drosophila melanogaster. Cytological data limiting the location of the white gene to a small portion of 3L and complementing the in situ results are also presented. Key words: Lucilia cuprina, white gene, in situ hybridization.

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Chromosomal distribution of the major insert in Drosophila melanogaster 28S rRNA genes

Genetics Research ◽

10.1017/s0016672300020176 ◽

1981 ◽

Vol 37 (2) ◽

pp. 209-214 ◽

Cited By ~ 35

Author(s):

W. J. Peacock ◽

R. Appels ◽

S. Endow ◽

D. Glover

Keyword(s):

Drosophila Melanogaster ◽

Polytene Chromosomes ◽

Ribosomal Gene ◽

Rrna Genes ◽

Major Type ◽

Type I ◽

28S Rrna ◽

Mitotic Chromosomes ◽

Chromosomal Distribution

SUMMARYThe major type I insert sequence for the 28S rRNA genes of Drosophila melanogaster has been mapped within the chromosomes using a probe synthesized from a cloned sequence containing the entire 5·4 kb segment. The genomic distribution was shown to be complex in that the insert sequence occurred next to many different types of sequences, in addition to occurring as an insert in the 28S rRNA genes of the X chromosome. In situ hybridization of mitotic chromosomes showed most of the insert units not contained in the ribosomal genes to be located near the ribosomal gene cluster on the X chromosome. Additional sites were detected in polytene chromosomes in region 102C, 8–12 and in the hetero-chromatin of the autosomes.

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Localizing genes in Drosophila melanogaster polytene chromosomes by fluorescence in situ hybridization

Journal of Cellular and Molecular Medicine ◽

10.1111/j.1582-4934.2001.tb00139.x ◽

2001 ◽

Vol 5 (1) ◽

pp. 74-78 ◽

Cited By ~ 1

Author(s):

L. Gavrila ◽

Al. Al. Ecovoiu ◽

Laura Monica Georgescu

Keyword(s):

Drosophila Melanogaster ◽

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Polytene Chromosomes

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A gene responsible for a cuticular hydrocarbon polymorphism in Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672398003723 ◽

1999 ◽

Vol 73 (3) ◽

pp. 189-203 ◽

Cited By ~ 65

Author(s):

JERRY A. COYNE ◽

CLAUDE WICKER-THOMAS ◽

JEAN-MARC JALLON

Keyword(s):

Drosophila Melanogaster ◽

Mating Behaviour ◽

Polytene Chromosomes ◽

Cuticular Hydrocarbon ◽

Sexual Isolation ◽

Detectable Effect ◽

Desaturase Gene ◽

The Difference ◽

The Right

Drosophila melanogaster is polymorphic for the major cuticular hydrocarbon of females. In most populations this hydrocarbon is 7,11-heptacosadiene, but females from Africa and the Caribbean usually possess low levels of 7,11-heptacosadiene and high quantities of its position isomer 5,9-heptacosadiene. Genetic analysis shows that the difference between these two morphs is due to variation at a single segregating factor located on the right arm of chromosome 3 near map position 51·5 and cytological position 87C–D. This is precisely the position of a desaturase gene previously sequenced using primers derived from yeast and mouse, and localized by in situ hybridization to the polytene chromosomes of D. melanogaster. Alleles of this desaturase gene may therefore be responsible for producing the two hydrocarbon morphs. Mating tests following the transfer of these isomers between females of the two morphs show that, in contrast to previous studies, the hydrocarbon profiles have no detectable effect on mating behaviour or sexual isolation.

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A Physical Map of the Polytenized Region (101EF–102F) of Chromosome 4 in Drosophila melanogaster

Genetics ◽

10.1093/genetics/155.3.1175 ◽

2000 ◽

Vol 155 (3) ◽

pp. 1175-1183

Author(s):

John Locke ◽

Lynn Podemski ◽

Nicole Aippersbach ◽

Hilary Kemp ◽

Ross Hodgetts

Keyword(s):

Drosophila Melanogaster ◽

Physical Map ◽

Polytene Chromosomes ◽

Chromosome 4 ◽

Chromosome Walking ◽

Bac Clones ◽

Satellite Repeats ◽

Entry Points ◽

Minimal Tiling

Abstract Chromosome 4, the smallest autosome (~5 Mb in length) in Drosophila melanogaster contains two major regions. The centromeric domain (~4 Mb) is heterochromatic and consists primarily of short, satellite repeats. The remaining ~1.2 Mb, which constitutes the banded region (101E–102F) on salivary gland polytene chromosomes and contains the identified genes, is the region mapped in this study. Chromosome walking was hindered by the abundance of moderately repeated sequences dispersed along the chromosome, so we used many entry points to recover overlapping cosmid and BAC clones. In situ hybridization of probes from the two ends of the map to polytene chromosomes confirmed that the cloned region had spanned the 101E–102F interval. Our BAC clones comprised three contigs; one gap was positioned distally in 102EF and the other was located proximally at 102B. Twenty-three genes, representing about half of our revised estimate of the total number of genes on chromosome 4, were positioned on the BAC contigs. A minimal tiling set of the clones we have mapped will facilitate both the assembly of the DNA sequence of the chromosome and a functional analysis of its genes.

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A study of ten families of transposable elements on X chromosomes from a population of Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672300028482 ◽

1989 ◽

Vol 54 (2) ◽

pp. 113-125 ◽

Cited By ~ 39

Author(s):

Brian Charlesworth ◽

Angela Lapid

Keyword(s):

Drosophila Melanogaster ◽

Transposable Elements ◽

Copy Number ◽

Distal Part ◽

Polytene Chromosomes ◽

Chromosome Band ◽

X Chromosomes ◽

High Frequencies ◽

Chromosome Element

SummaryData were collected on the distribution of ten families of transposable elements among fourteen X chromosomes isolated from a natural population of Drosophila melanogaster, by means of in situ hybridization to polytene chromosomes. It was found that, with the exception of roo, the copy number per chromosome followed a Poisson distribution. There was no evidence for linkage disequilibrium, either within or between families. Some pairs of families of elements were correlated with respect to the identity of the sites that were occupied in the sample, although there was no evidence for a correlation with respect to the sites at which elements attained relatively high frequencies. Elements appeared to be distributed randomly along the distal part of the X chromosome. There was, however, a strong tendency for elements to accumulate at the base of the chromosome. Element frequencies per chromosome band were generally low, except at the base of the chromosome where bands in subdivisions 19E and 20A sometimes had high frequencies of occupation. These results are discussed in the light of models of the population dynamics of transposable elements. It is concluded that they provide strong evidence for the operation of a force or forces opposing transpositional increase in copy number. The accumulation of elements at the base of the chromosome is consistent with the idea that unequal exchange between elements at non-homologous sites is such a force, although other possibilities cannot be excluded at present. The data suggest that the rate of transposition per element per generation is of the order of 10−4, for the elements included in this study.

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