scholarly journals Novitski’s Distal shift in Paracentric Inversion Evolution

2018 ◽  
Author(s):  
Spencer A. Koury
Keyword(s):  
Chromosome Evolution ◽  
Meiotic Drive ◽  
Distinct Pattern ◽  
Paracentric Inversion ◽  
Drosophila Pseudoobscura ◽  
Crossing Over ◽  
Female Meiosis ◽  
Chromosomal Inversions ◽  
Underlying Principle

AbstractIn Drosophila pseudoobscura younger chromosomal inversions tend to be found distal to older inversions. By examining phylogenetic series of overlapping inversions for 134 gene arrangements of 13 chromosomes this pattern was extended to five additional Drosophila species. This distinct pattern arose repeatedly and independently in all six species and likely reflects an underlying principle of chromosome evolution. In this study it is illustrated how transmission of distal inversions is always favored in female meiosis when crossing over in homosequential regions of overlapping inversions generates asymmetric dyads. This cytogenetic mechanism for female meiotic drive is described in detail and advanced as an explanation for the distal shift in phylogenetic series of overlapping inversions as well as several better known patterns in the evolution of serially inverted chromosomes.

scholarly journals Divergence Between the Drosophila pseudoobscura and D. persimilis Genome Sequences in Relation to Chromosomal Inversions

Genetics ◽  
2007 ◽  
Vol 177 (3) ◽  
pp. 1417-1428 ◽  
Author(s):  
Mohamed A. F. Noor ◽  
David A. Garfield ◽  
Stephen W. Schaeffer ◽  
Carlos A. Machado
Keyword(s):  
Drosophila Pseudoobscura ◽  
Genome Sequences ◽  
Chromosomal Inversions

scholarly journals Sperm should evolve to make female meiosis fair.

2014 ◽  
Author(s):  
Yaniv Brandvain ◽  
Graham Coop
Keyword(s):  
Population Genetic ◽  
Animal Species ◽  
Meiotic Drive ◽  
Female Meiosis ◽  
Genetic Theory ◽  
Evolutionary Advantage ◽  
The Face ◽  
Perceived Danger ◽  
Organismal Fitness

Genomic conflicts arise when an allele gains an evolutionary advantage at a cost to organismal fitness. Oogenesis is inherently susceptible to such conflicts because alleles compete for inclusion into the egg. Alleles that distort meiosis in their favor (i.e. meiotic drivers) often decrease organismal fitness, and therefore indirectly favor the evolution of mechanisms to suppress meiotic drive. In this light, many facets of oogenesis and gametogenesis have been interpreted as mechanisms of protection against genomic outlaws. That females of many animal species do not complete meiosis until after fertilization, appears to run counter to this interpretation, because this delay provides an opportunity for sperm-acting alleles to meddle with the outcome of female meiosis and help like alleles drive in heterozygous females. Contrary to this perceived danger, the population genetic theory presented herein suggests that, in fact, sperm nearly always evolve to increase the fairness of female meiosis in the face of genomic conflicts. These results are consistent with the apparent sperm dependence of the best characterized female meiotic drivers in animals. Rather than providing an opportunity for sperm collaboration in female meiotic drive, the 'fertilization requirement' indirectly protects females from meiotic drivers by providing sperm an opportunity to suppress drive.

scholarly journals THE GENOTYPIC CONTROL OF CROSSING OVER IN DROSOPHILA PSEUDOOBSCURA

Genetics ◽  
1954 ◽  
Vol 39 (5) ◽  
pp. 677-691
Author(s):  
Robert Paul Levine ◽  
Elizabeth Epling Levine
Keyword(s):  
Drosophila Pseudoobscura ◽  
Crossing Over ◽  
Genotypic Control

scholarly journals VARIABLE CROSSING OVER ARISING IN DIFFERENT STRAINS OF DROSOPHILA PSEUDOOBSCURA

Genetics ◽  
1955 ◽  
Vol 40 (3) ◽  
pp. 399-405
Author(s):  
R P Levine ◽  
Elizabeth E Levine
Keyword(s):  
Drosophila Pseudoobscura ◽  
Crossing Over ◽  
Different Strains

scholarly journals Lack of underdominance in a naturally occurring pericentric inversion in Drosophila melanogaster and its implications for chromosome evolution.

Genetics ◽  
1991 ◽  
Vol 129 (3) ◽  
pp. 791-802
Author(s):  
J A Coyne ◽  
S Aulard ◽  
A Berry
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Selection ◽  
Genetic Drift ◽  
Related Species ◽  
Pericentric Inversion ◽  
Chromosome Evolution ◽  
Natural Populations ◽  
Crossing Over ◽  
Closely Related Species ◽  
Naturally Occurring

Abstract In(2LR)PL is a large pericentric inversion polymorphic in populations of Drosophila melanogaster on two Indian Ocean islands. This polymorphism is puzzling: because crossing over in female heterokaryotypes produces inviable zygotes, such inversions are thought to be underdominant and should be quickly eliminated from populations. The observed fixation for such inversions among related species has led to the idea that genetic drift can cause chromosome evolution in opposition to natural selection. We found, however, that In(2LR)PL is not underdominant for fertility, as heterokaryotypic females produce perfectly viable eggs. Genetic analysis shows that the lack of underdominance results from the nearly complete absence of crossing over in the inverted region. This phenomenon is probably caused by mechanical and not genetic factors, because crossing over is not suppressed in In(2LR)PL homokaryotypes. Our observations do not support the idea that the fixation of pericentric inversions among closely related species implies the action of genetic drift overcoming strong natural selection in very small populations. If chromosome arrangements vary in their underdominance, it is those with the least disadvantage as heterozygotes, like In(2LR)PL, that will be polymorphic or fixed in natural populations.

EVIDENCE FOR EXTENSIVE GENETIC DIFFERENTIATION BETWEEN THE SEX-RATIO AND THE STANDARD ARRANGEMENT OF DROSOPHILA PSEUDOOBSCURA AND D. PERSIMILIS AND IDENTIFICATION OF HYBRID STERILITY FACTORS

Genetics ◽  
1983 ◽  
Vol 105 (1) ◽  
pp. 71-86
Author(s):  
Chung-I Wu ◽  
Andrew T Beckenbach
Keyword(s):  
Sex Ratio ◽  
Genetic Differentiation ◽  
Genetic Background ◽  
Hybrid Sterility ◽  
Strong Support ◽  
Meiotic Drive ◽  
Complete Loss ◽  
Drosophila Pseudoobscura ◽  
Drosophila Persimilis ◽  
Standard Arrangement

ABSTRACT This study deals with sex-ratio genes tightly linked within the Sex-Ratio inversion. By taking advantage of the fact that the Sex-Ratio chromosome of Drosophila persimilis [SR(B)] is homosequential to the Standard chromosome of D. pseudoobscura [ST(A)], we carried out two reciprocal introgression experiments. Individual segments of SR(B) or ST(A) were introgressed into the genome of D. pseudoobscura or D. persimilis, respectively. Males possessing a hybrid SR(B)-ST(A) X chromosome and a genetic background derived from either of the two species were tested for fertility and sex-ratio expression.—It was found that, in terms of the meiotic drive genes, the Sex-Ratio chromosome differs extensively from the Standard chromosome. Because recombinations of these genes result in a complete loss of sex-ratio expression, this finding lends strong support to the hypothesis of gene coadaptation. Coadaptation, in this context, is the advantage of being transmitted preferentially. In light of this finding, the evolution of the sex-ratio system in these two sibling species is discussed.—Introgression experiments also yielded information about hybrid sterility. With reciprocal introgression, sterility interactions were found to be "asymmetric." The asymmetry is fully expected from the viewpoint of evolution of postmating reproductive isolation.

scholarly journals An assessment of the immune costs associated with meiotic drive elements in Drosophila

2019 ◽  
Vol 286 (1911) ◽  
pp. 20191534 ◽  
Author(s):  
Jenna Kay Lea ◽  
Robert L. Unckless
Keyword(s):  
Meiotic Drive ◽  
Immune Gene ◽  
Immune Defence ◽  
Deleterious Mutations ◽  
Wild Type ◽  
Selfish Genetic Elements ◽  
Fitness Effects ◽  
Immune Gene Expression ◽  
Chromosomal Inversions ◽  
Segregation Distorter

Most organisms are constantly adapting to pathogens and parasites that exploit their host for their own benefit. Less studied, but perhaps more ubiquitous, are intragenomic parasites or selfish genetic elements. These include transposable elements, selfish B chromosomes and meiotic drivers that promote their own replication without regard to fitness effects on hosts. Therefore, intragenomic parasites are also a constant evolutionary pressure on hosts. Gamete-killing meiotic drive elements are often associated with large chromosomal inversions that reduce recombination between the drive and wild-type chromosomes. This reduced recombination is thought to reduce the efficacy of selection on the drive chromosome and allow for the accumulation of deleterious mutations. We tested whether gamete-killing meiotic drive chromosomes were associated with reduced immune defence against two bacterial pathogens in three species of Drosophila . We found little evidence of reduced immune defence in lines with meiotic drive. One line carrying the Drosophila melanogaster autosomal Segregation Distorter did show reduced defence, but we were unable to attribute that reduced defence to either genotype or immune gene expression differences. Our results suggest that though gamete-killing meiotic drive chromosomes probably accumulate deleterious mutations, those mutations do not result in reduced capacity for immune defence.

A 11.7-Mb Paracentric Inversion in Chromosome 1q Detected in Prenatal Diagnosis Associated with Familial Intellectual Disability

2015 ◽  
Vol 146 (2) ◽  
pp. 109-114
Author(s):  
Maria A. Rigola ◽  
Neus Baena ◽  
Vicenç Català ◽  
Iris Lozano ◽  
Elisabet Gabau ◽  
...  
Keyword(s):  
Mental Retardation ◽  
Intellectual Disability ◽  
Prenatal Diagnosis ◽  
Paracentric Inversion ◽  
Position Effects ◽  
Chromosomal Alterations ◽  
Molecular Cytogenetic ◽  
Chromosome 1Q ◽  
Chromosomal Inversions ◽  
Cytogenetic Methods

Most apparent balanced chromosomal inversions are usually clinically asymptomatic; however, infertility, miscarriages, and mental retardation have been reported in inversion carriers. We present a small family with a paracentric inversion 1q42.13q43 detected in routine prenatal diagnosis. Molecular cytogenetic methods defined the size of the inversion as 11.7 Mb and excluded other unbalanced chromosomal alterations in the patients. Our findings suggest that intellectual disability is caused by dysfunction, disruption, or position effects of genes located at or near the breakpoints involved in this inversion.

A CROSSOVER SUPPRESSOR-ENHANCER SYSTEM IN THE MOSQUITO AEDES AEGYPTI

1971 ◽  
Vol 13 (3) ◽  
pp. 561-577 ◽  
Author(s):  
Satish C. Bhalla
Keyword(s):  
Linkage Group ◽  
Reciprocal Translocation ◽  
Paracentric Inversion ◽  
Chromosome 1 ◽  
Crossing Over ◽  
Linkage Groups ◽  
Group Iii ◽  
Partial Sterility ◽  
The Right ◽  
And Inversion

A small reciprocal translocation T(1;2)1 involving chromosomes 1 and 2 and a paracentric inversion In(1)3 on m chromosome (1) of A. aegypti interact to give peculiar but consistent crossover values. The system is termed COSES and is associated with partial sterility. In females it suppresses crossing over tremendously to the right of bz and enhances crossing over to its left. In the males it enhances crossing over to the right of m (only 3 crossover units away from bz) hut the region to its left remains unaffected. COSES also displays interchromosomal effects by enhancing crossing over in linkage group III. Cytological and genetic evidence for the presence of translocation and inversion are presented. All three pairs of chromosomes are correlated to the three linkage groups.

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