scholarly journals Restriction map variation at the adh locus of Drosophila melanogaster in inverted and noninverted chromosomes.

Genetics ◽  
1988 ◽  
Vol 119 (1) ◽  
pp. 135-140
Author(s):  
M Aguade
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Evolutionary History ◽  
Restriction Site ◽  
Restriction Enzymes ◽  
Restriction Map ◽  
Allozyme Polymorphism ◽  
Length Polymorphisms ◽  
History Of ◽  
Restriction Site Polymorphisms

Abstract Restriction map variation among 39 Standard and 40 In(2L)t chromosomes extracted from a Spanish natural population of Drosophila melanogaster was investigated for a 2.7-kb region encompassing the Adh locus with ten four-cutter restriction enzymes. A total of 20 polymorphisms were detected, representing 15 restriction site polymorphisms, 4 length polymorphisms and the allozyme polymorphism. Variation at the DNA level was compared among St-Adh(F), St-Adh(S) and t-Adh(S) chromosomes. t-Adh(S) chromosomes show a higher level of variation than St-Adh(F) chromosomes. This suggests that In(2L)t arose before the fast/slow allozyme divergence in the evolutionary history of D. melanogaster.

scholarly journals Reduced variation in the yellow-achaete-scute region in natural populations of Drosophila melanogaster.

Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 607-615 ◽  
Author(s):  
M Aguade ◽  
N Miyashita ◽  
C H Langley
Keyword(s):  
Drosophila Melanogaster ◽  
Restriction Site ◽  
Natural Populations ◽  
Negative Relationship ◽  
Relative Number ◽  
Restriction Enzymes ◽  
Crossing Over ◽  
Length Polymorphisms ◽  
Polymorphic Restriction ◽  
Restriction Site Polymorphisms

Abstract Restriction map variation in 64 X chromosome lines extracted from three different populations of Drosophila melanogaster was investigated with seven six-nucleotide-recognizing restriction enzymes for a 106-kb region encompassing the yellow gene and the achaete-scute complex that is located in the region of reduced crossing over close to the telomere. Nine restriction site polymorphisms (out of 176 sites scored) and 19 length polymorphisms (15 insertions and 4 deletions) were detected. The estimated level of heterozygosity per nucleotide, H = 0.0003, is much lower than that reported for autosomal and sex-linked loci located in regions with normal levels of crossing over. The overall frequency of polymorphic restriction sites is reduced. Six out of nine restriction site polymorphisms are unique and the other three have frequencies less than 0.17. Some large insertions have reached relatively high frequencies, 0.08 to 0.17. Consistent with the theoretically predicted negative relationship between crossing over and the magnitude of linkage disequilibrium, an increase in the relative number of nonrandom associations was observed in the y-ac-sc region.

scholarly journals The genetic structure of natural populations of Drosophila melanogaster. XXII. Comparative study of DNA polymorphisms in northern and southern natural populations.

Genetics ◽  
1991 ◽  
Vol 129 (3) ◽  
pp. 753-761
Author(s):  
T S Takano ◽  
S Kusakabe ◽  
T Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Drift ◽  
Nucleotide Diversity ◽  
Restriction Site ◽  
Natural Populations ◽  
Dna Polymorphisms ◽  
Restriction Map ◽  
Random Genetic Drift ◽  
Two Populations ◽  
Restriction Site Polymorphisms

Abstract Restriction map variation in four gene regions (Adh, Amy, Pu and Gpdh) was surveyed for 86 second chromosomes from northern (Aomori) and southern (Ogasawara) Japanese populations of Drosophila melanogaster (43 chromosomes from each population). The regions examined cover a total of 62 kilobases. Estimates of nucleotide diversity (pi) were approximately constant across the gene regions and populations examined. The distribution of restriction site polymorphisms was compatible with the expectation from the neutral mutation-random genetic drift hypothesis, but insertion/deletion polymorphisms were not consistent with it. While the two populations shared a majority of restriction site polymorphisms, frequencies of individual restriction site variants were significantly different between the two populations at 7 out of 35 segregating sites. In addition, an insertion in the Amy region was found in 15 chromosomes from the Ogasawara sample but absent in the Aomori sample. A considerable difference was observed in the number of rare insertions and deletions between the two populations. The numbers of aberrations uniquely represented were 16 in the Ogasawara sample and only 3 in the Aomori sample. These findings suggest that the two populations were differentiated from each other to some degree by means of random genetic drift and/or other factors.

Haemophilia A in a Female: Study of a Family Using Intragenic and Extragenic Restriction Site Polymorphisms

1988 ◽  
Vol 60 (01) ◽  
pp. 102-106 ◽  
Author(s):  
G Piétu ◽  
N Thomas-Maison ◽  
P Sié ◽  
M J Larrieu ◽  
D Meyer
Keyword(s):  
Cdna Probe ◽  
Normal Karyotype ◽  
Restriction Enzymes ◽  
Carrier Status ◽  
Haemophilia A ◽  
Bleeding Tendency ◽  
Excessive Bleeding ◽  
Length Polymorphisms ◽  
The Family ◽  
Restriction Site Polymorphisms

SummaryRestriction fragment length polymorphisms(RFLPs) were studied in a large Algerian family which includes 6 haemophiliacs and a previously described case of female haemophilia A. The female propositus is 66 years old with a normal karyotype. Her parents are first cousins. Her 3 sons are haemophiliacs and her 3 daughters with affected children are obligate carriers. The proband has an excessive bleeding tendency and markedly reduced levels of F. VIII (VIII C 0.03 U/ml, VIII Ag 0.01 U/ml) with elevated vWF Ag (2.30 U/ml), similar to the levels observed in affected males from the family. Four RFLPs can be identified by Southern blotting after digesting genomic DNA with the restriction enzymes Bcl I, Bgl I, Kpn I/Xba I and Taq I and hybridization with a 647 bp Stu I/Sca I F. VIII genomic probe, a 1.8 Kb EcoRI F. VIII cDNA probe, a 1.0 Kb EcoRI/Sst I fragment of intron 22 and the extragenic probe ST 14, respectively. With these four RFLPS, the propositus was found to be homozygous for the alleles segregating in this family with the abnormal X-chromosome. The carrier status was proven in a granddaughter and excluded in another. In conclusion, this RFLP linkage analysis is another argument to suggest that the propositus, a rare case of female haemophilia, is homozygous for the abnormal gene.

scholarly journals Isolation of the Drosophila melanogaster dunce chromosomal region and recombinational mapping of dunce sequences with restriction site polymorphisms as genetic markers.

1984 ◽  
Vol 4 (2) ◽  
pp. 358-367 ◽  
Author(s):  
R L Davis ◽  
N Davidson
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Meiotic Recombination ◽  
Restriction Site ◽  
Chromosomal Region ◽  
Nucleotide Metabolism ◽  
X Chromosomes ◽  
Chromosomal Walking ◽  
Chromosome Bands ◽  
Restriction Site Polymorphisms

Using the method of chromosomal walking, we have isolated a contiguous region of the Drosophila melanogaster X chromosome which corresponds to salivary gland chromosome bands 3C12 to 3D4. This five-band region contains approximately 100 kilobases of DNA, including those sequences comprising dunce, a gene which functions in memory and cyclic nucleotide metabolism. Genome blots of DNA from flies carrying several different chromosomal aberrations with breakpoints in the region have been probed with the isolated clones to map the breakpoints on the cloned DNA and to delimit dunce sequences. This has localized dunce to a 50-kilobase region. In addition, we have searched this 50-kilobase region for restriction site polymorphisms between X chromosomes from different Drosophila strains by genome blotting experiments, and we have followed the segregation of detected polymorphisms and dunce alleles after meiotic recombination. The data map one dunce mutation between two polymorphisms located 10 to 12 kilobases apart.

scholarly journals Recombination can initiate and terminate at a large number of sites within the rosy locus of Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 118 (2) ◽  
pp. 261-266
Author(s):  
S H Clark ◽  
A J Hilliker ◽  
A Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Markers ◽  
Restriction Site ◽  
Intragenic Recombination ◽  
Dna Homology ◽  
Coding Region ◽  
Heterozygous Genotype ◽  
Order Of Magnitude ◽  
Dna Restriction ◽  
Restriction Site Polymorphisms

Abstract This report presents the results of a recombination experiment designed to question the existence of special sites for the initiation or termination of a recombination heteroduplex within the region of the rosy locus. Intragenic recombination events were monitored between two physically separated rosy mutant alleles ry301 and ry2 utilizing DNA restriction site polymorphisms as genetic markers. Both ry301 and ry2 are known from previous studies to be associated with gene conversion frequencies an order of magnitude lower than single site mutations. The mutations are associated with large, well defined insertions located as internal sites within the locus in prior intragenic mapping studies. On the molecular map, they represent large insertions approximately 2.7 kb apart in the second and third exons, respectively, of the XDH coding region. The present study monitors intragenic recombination in a mutant heterozygous genotype in which DNA homology is disrupted by these large discontinuities, greater than the region of DNA homology and flanking both sides of the locus. If initiation/or termination requires separate sites at either end of the locus, then intragenic recombination within the rosy locus of the heterozygote should be eliminated. Contrary to expectation, significant recombination between these sites is seen.

scholarly journals Extensive linkage disequilibrium in the achaete-scute complex of Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 121-129
Author(s):  
J N Macpherson ◽  
B S Weir ◽  
A J Leigh Brown
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Natural Population ◽  
Nucleotide Diversity ◽  
Single Site ◽  
Restriction Map ◽  
X Chromosomes ◽  
Linkage Disequilibria ◽  
Restriction Sites ◽  
Gametic Association

Abstract We have analyzed the level of gametic association between restriction map variants in a sample of 44 X chromosomes from a natural population of Drosophila melanogaster. Of 21 pairwise tests involving 7 restriction map polymorphisms in the yellow-achaete-scute complex, 17 were found to be significant, including some between restriction sites over 80 kb apart. Three-way linkage disequilibria and their variances were also estimated for all 35 three-way comparisons between these loci. Twelve such tests were found to be significant, again spanning distances of up to 80 kb on the restriction map. Only 9 of a possible 128 haplotypes were represented in the sample and 8 of these could be linked together by changes at a single site. The strength of these associations at y-ac-sc is unusual by comparison with studies on other regions of the genome of D. melanogaster, and is consistent with the very low level of recombination which has been reported for the complex. However, our estimate of nucleotide diversity in the region is not significantly different from those made for some other loci in this species.

scholarly journals Evidence for Genetic Hitchhiking Effect Associated With Insecticide Resistance in Aedes aegypti

Genetics ◽  
1998 ◽  
Vol 148 (2) ◽  
pp. 793-800
Author(s):  
Guiyun Yan ◽  
Dave D Chadee ◽  
David W Severson
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Aedes Aegypti ◽  
Evolutionary History ◽  
Large Fraction ◽  
Target Site ◽  
Chromosome 1 ◽  
Disease Epidemiology ◽  
Length Polymorphisms ◽  
History Of

Abstract Information on genetic variation within and between populations is critical for understanding the evolutionary history of mosquito populations and disease epidemiology. Previous studies with Drosophila suggest that genetic variation of selectively neutral loci in a large fraction of genome may be constrained by fixation of advantageous mutations associated with hitchhiking effect. This study examined restriction fragment length polymorphisms of four natural Aedes aegypti mosquito populations from Trinidad and Tobago, at 16 loci. These populations have been subjected to organophosphate (OP) insecticide treatments for more than two decades, while dichlor-diphenyltrichlor (DDT) was the insecticide of choice prior to this period. We predicted that genes closely linked to the OP target loci would exhibit reduced genetic variation as a result of the hitchhiking effect associated with intensive OP insecticide selection. We also predicted that genetic variability of the genes conferring resistance to DDT and loci near the target site would be similar to other unlinked loci. As predicted, reduced genetic variation was found for loci in the general chromosomal region of a putative OP target site, and these loci generally exhibited larger FST values than other random loci. In contrast, the gene conferring resistance to DDT and its linked loci show polymorphisms and genetic differentiation similar to other random loci. The reduced genetic variability and apparent gene deletion in some regions of chromosome 1 likely reflect the hitchhiking effect associated with OP insecticide selection.

scholarly journals A Cladistic Analysis of Phenotypic Associations With Haplotypes Inferred From Restriction Endonuclease Mapping. I. Basic Theory and an Analysis of Alcohol Dehydrogenase Activity in Drosophila

Genetics ◽  
1987 ◽  
Vol 117 (2) ◽  
pp. 343-351 ◽  
Author(s):  
Alan R Templeton ◽  
Eric Boerwinkle ◽  
Charles F Sing
Keyword(s):  
Linkage Disequilibrium ◽  
Alcohol Dehydrogenase ◽  
Restriction Site ◽  
Cladistic Analysis ◽  
Alcohol Dehydrogenase Activity ◽  
History Of ◽  
Endonuclease Mapping ◽  
Nested Analysis ◽  
Adh Activity ◽  
Restriction Site Polymorphisms

ABSTRACT Because some genes have been cloned that have a known biochemical or physiological function, genetic variation can be measured in a population at loci that may directly influence a phenotype of interest. With this measured genotype approach, specific alleles or haplotypes in the probed DNA region can be assigned phenotypic effects. In this paper we address several problems encountered in implementing the measured genotype approach with restriction site data. A number of analytical problems arise in part as a consequence of the linkage disequilibrium that is commonly encountered when dealing with small DNA regions: 1) different restriction site polymorphisms are not statistically independent, 2) the sites being measured are not likely to be the direct cause of the associated phenotypic effects, 3) haplotype classes may be phenotypically heterogeneous, and 4) the sites that are most strongly associated with phenotypic effects are not necessarily the most closely linked to the actual genetic cause of the effects. When recombination and gene conversion are rare, the primary cause of linkage disequilibrium is history (mutational origin, genetic drift, hitchhiking, etc.). We deal with historical association directly by producing a cladogram that partially reconstructs the evolutionary history of the present-day haplotype variability. The cladogram defines a nested analysis of variance that simultaneously detects phenotypic effects, localizes the effects within the cladogram, and identifies haplotypes that are potentially heterogeneous in their phenotypic associations. The power of this approach is illustrated by an analysis of the associations between alcohol dehydrogenase (ADH) activity and restriction site variability in a 13-kb fragment surrounding the ADH locus in Drosophila melanogaster.

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