Evidence of extensive genetic exchange in the rp49 region among polymorphic chromosome inversions in Drosophila subobscura.

Abstract Restriction map variation in 107 lines extracted from two natural populations of Drosophila subobscura was investigated with seven four-nucleotide-recognizing enzymes in a 1.6-kb region including the rp49 gene, that is located very close to the proximal breakpoint of inversion O3. Fourteen restriction site and 8 length polymorphisms, resulting in 73 haplotypes, have been identified. Estimated heterozygosity per nucleotide, pi = 0.0045, is comparable to the average nucleotide variation observed in Drosophila melanogaster. Because of the location of the rp49 region in D. subobscura, variation in three different gene arrangements-Ost, O3 + 4 and O3 + 4 + 8-has been compared. Out of 14 restriction site polymorphisms, 3 are shared by Ost, O3 + 4 and O3 + 4 + 8, and 3 additional ones are shared by Ost and O3 + 4, evidencing extensive genetic exchange among these polymorphic inversions. In agreement with previous data, the higher level of variation of O3 + 4 (as measured by haplotype diversity and nucleotide variation) suggests that O3 + 4 may be ancestral in relationship to extant gene arrangements.

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

Genetics ◽

10.1093/genetics/122.3.607 ◽

1989 ◽

Vol 122 (3) ◽

pp. 607-615 ◽

Cited By ~ 9

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.

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Molecular Population Genetics of the rp49 Gene Region in Different Chromosomal Inversions of Drosophila subobscura

Genetics ◽

10.1093/genetics/151.1.189 ◽

1999 ◽

Vol 151 (1) ◽

pp. 189-202 ◽

Cited By ~ 8

Author(s):

Julio Rozas ◽

Carmen Segarra ◽

Griselda Ribó ◽

Montserrat Aguadé

Keyword(s):

Drosophila Subobscura ◽

Gene Region ◽

Central Position ◽

Nucleotide Variation ◽

Nucleotide Polymorphism ◽

Chromosomal Inversions ◽

Molecular Population Genetics ◽

Expansion Model ◽

Time Of Origin ◽

Rp49 Gene

Abstract Nucleotide variation at the ribosomal protein 49 (rp49) gene region has been studied in 75 lines of Drosophila subobscura belonging to four chromosomal arrangements (Ost, O3+4, O3+4+8, and O3+4+23). The location of the rp49 gene region within the inversion loop differs among heterokaryotypes: it is very close to one of the breakpoints in heterozygotes involving Ost chromosomes, while it is in a more central position in all other heterokaryotypes. The distribution of nucleotide polymorphism in the different arrangements is consistent with a monophyletic origin of the inversions. The data also provide evidence that gene conversion and possibly double crossover are involved in shuffling nucleotide variation among gene arrangements. The analyses reveal that the level of genetic exchange is higher when the region is located in a more central position of the inverted fragment than when it is close to the breakpoints. The pairwise difference distributions as well as the negative values of Tajima's and Fu and Li's statistics further support the hypothesis that nucleotide variation within chromosomal arrangements still reflects expansion after the origin of the inversions. Under the expansion model, we have estimated the time of origin of the studied inversions.

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

Genetics ◽

10.1093/genetics/119.1.135 ◽

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.

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

Genetics ◽

10.1093/genetics/129.3.753 ◽

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.

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Reproduction in Trypanosomatids: Past and Present

Biology ◽

10.3390/biology10060471 ◽

2021 ◽

Vol 10 (6) ◽

pp. 471

Author(s):

Camino Gutiérrez-Corbo ◽

Bárbara Domínguez-Asenjo ◽

María Martínez-Valladares ◽

Yolanda Pérez-Pertejo ◽

Carlos García-Estrada ◽

...

Keyword(s):

Low Income ◽

Phenotypic Diversity ◽

Natural Populations ◽

Genetic Exchange ◽

Health Concern ◽

Current Debate ◽

Naturally Occurring ◽

Experimental Works ◽

Genomic Recombination ◽

The Impact

Diseases caused by trypanosomatids (Sleeping sickness, Chagas disease, and leishmaniasis) are a serious public health concern in low-income endemic countries. These diseases are produced by single-celled parasites with a diploid genome (although aneuploidy is frequent) organized in pairs of non-condensable chromosomes. To explain the way they reproduce through the analysis of natural populations, the theory of strict clonal propagation of these microorganisms was taken as a rule at the beginning of the studies, since it partially justified their genomic stability. However, numerous experimental works provide evidence of sexual reproduction, thus explaining certain naturally occurring events that link the number of meiosis per mitosis and the frequency of mating. Recent techniques have demonstrated genetic exchange between individuals of the same species under laboratory conditions, as well as the expression of meiosis specific genes. The current debate focuses on the frequency of genomic recombination events and its impact on the natural parasite population structure. This paper reviews the results and techniques used to demonstrate the existence of sex in trypanosomatids, the inheritance of kinetoplast DNA (maxi- and minicircles), the impact of genetic exchange in these parasites, and how it can contribute to the phenotypic diversity of natural populations.

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Reciprocal recombination and the evolution of the ribosomal gene family of Drosophila melanogaster.

Genetics ◽

10.1093/genetics/122.3.617 ◽

1989 ◽

Vol 122 (3) ◽

pp. 617-624 ◽

Cited By ~ 1

Author(s):

S M Williams ◽

J A Kennison ◽

L G Robbins ◽

C Strobeck

Keyword(s):

Drosophila Melanogaster ◽

Gene Family ◽

Ribosomal Rna ◽

Natural Populations ◽

Ribosomal Gene ◽

Gene Region ◽

Ribosomal Rna Gene ◽

Reciprocal Recombination ◽

Y Chromosomes ◽

Length Polymorphisms

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.

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Contrasting Histories of Three Gene Regions Associated With In(3L)Payne of Drosophila melanogaster

Genetics ◽

10.1093/genetics/144.4.1565 ◽

1996 ◽

Vol 144 (4) ◽

pp. 1565-1575 ◽

Cited By ~ 3

Author(s):

Esteban Hasson ◽

Walter F Eanes

Keyword(s):

Drosophila Melanogaster ◽

Sequence Variation ◽

Present Report ◽

Genetic Exchange ◽

Nucleotide Variation ◽

Distal Breakpoint ◽

Esterase 6 ◽

The Common ◽

Neutrality Tests ◽

Hsp83 Gene

In the present report, we studied nucleotide variation in three gene regions of Drosophila melanogaster, spanning >5 kb and showing different degrees of association with the cosmopolitan inversion In(3-L)Payne. The analysis of sequence variation in the regions surrounding the breakpoints and the heat shock 83 (Hsp83) gene locus, located close to the distal breakpoint, revealed the absence of shared polymorphisms and the presence of a number of fixed differences between arrangements, indicating absence of genetic exchange. In contrast, for the esterase-6 gene region, located in the center of the inversion, we observed the presence of shared polymorphisms between arrangements suggesting genetic exchange. In the regions close to the breakpoints, the common St arrangement is 10 times more polymorphic than inverted chromosomes. We propose that the lack of recombination between arrangements in these regions coupled with genetic hitchhiking is the best explanation for the low heterozygosity observed in inverted lines. Using the data for the breakpoints, we estimate that this inversion polymorphism is around 0.36 million yr old. Although it is widely accepted that inversions are examples of balanced polymorphisms, none of the current neutrality tests including our Monte Carlo simulations showed significant departure from neutral expectations.

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Species ofBorreliadistinguished by restriction site polymorphisms in 16S rRNA genes

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.1993.tb06392.x ◽

1993 ◽

Vol 111 (2-3) ◽

pp. 239-243 ◽

Cited By ~ 7

Author(s):

David Ralph ◽

Daniele Postic ◽

Guy Baranton ◽

Charles Pretzman ◽

Michael McClelland

Keyword(s):

16S Rrna ◽

Restriction Site ◽

16S Rrna Genes ◽

Rrna Genes ◽

Restriction Site Polymorphisms

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Nucleotide Variation and Conservation at the dpp Locus, a Gene Controlling Early Development in Drosophila

Genetics ◽

10.1093/genetics/145.2.311 ◽

1997 ◽

Vol 145 (2) ◽

pp. 311-323 ◽

Cited By ~ 2

Author(s):

Brent Richter ◽

Manyuan Long ◽

R C Lewontin ◽

Eiji Nitasaka

Keyword(s):

Linkage Disequilibrium ◽

Amino Acid ◽

Gene Conversion ◽

Haplotype Diversity ◽

Amino Acid Replacement ◽

Nucleotide Variation ◽

Nucleotide Level ◽

Untranslated Sequence ◽

Gene Coding ◽

Large Intron

A study of polymorphism and species divergence of the dpp gene of Drosophila has been made. Eighteen lines from a population of D. melanogaster were sequenced for 5200 bp of the Hin region of the gene, coding for the dpp polypeptide. A comparison was made with sequence from D. simulans. Ninety-six silent polymorphisms and three amino acid replacement polymorphisms were found. The overall silent polymorphism (0.0247) is low, but haplotype diversity (0.0066 for effectively silent sites and 0.0054 for all sites) is in the range found for enzyme loci. Amino acid variation is absent in the N-terminal signal peptide, the C-terminal TGF-β peptide and in the N-terminal half of the pro-protein region. At the nucleotide level there is strong conservation in the middle half of the large intron and in the 3′ untranslated sequence of the last exon. The 3′ untranslated conservation, which is perfect for 110 bp among all the divergent species, is unexplained. There is strong positive linkage disequilibrium among polymorphic sites, with stretches of apparent gene conversion among originally divergent sequences. The population apparently is a migration mixture of divergent clades.

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Assignment of two mitochondrially synthesized polypeptides to human mitochondrial DNA and their use in the study of intracellular mitochondrial interaction

Molecular and Cellular Biology ◽

10.1128/mcb.2.1.30-41.1982 ◽

1982 ◽

Vol 2 (1) ◽

pp. 30-41

Author(s):

N A Oliver ◽

D C Wallace

Keyword(s):

Mitochondrial Dna ◽

Restriction Site ◽

Mitochondrial Protein ◽

Mitochondrial Protein Synthesis ◽

Human Mitochondrial Dna ◽

Ht1080 Cells ◽

Mitochondrial Dnas ◽

A Cell ◽

Dna Restriction ◽

Restriction Site Polymorphisms

Two mitochondrially synthesized marker polypeptides, MV-1 and MV-2, were found in human HeLa and HT1080 cells. These were assigned to the mitochondrial DNA in HeLa-HT1080 cybrids and hybrids by demonstrating their linkage to cytoplasmic genetic markers. These markers include mitochondrial DNA restriction site polymorphisms and resistance to chloramphenicol, an inhibitor of mitochondrial protein synthesis. In the absence of chloramphenicol, the expression of MV-1 and MV-2 in cybrids and hybrids was found to be directly proportional to the ratio of the parental mitochondrial DNAs. In the presence of chloramphenicol, the marker polypeptide linked to the chloramphenicol-sensitive mitochondrial DNA continued to be expressed. This demonstrated that resistant and sensitive mitochondrial DNAs can cooperate within a cell for gene expression and that the CAP-resistant allele was dominant or codominant to sensitive. Such cooperation suggests that mitochondrial DNAs can be exchanged between mitochondria.

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