scholarly journals Double trouble: combined action of meiotic drive and Wolbachia feminization in Eurema butterflies

2015 ◽  
Vol 11 (5) ◽  
pp. 20150095 ◽  
Author(s):  
Peter Kern ◽  
James M. Cook ◽  
Daisuke Kageyama ◽  
Markus Riegler
Keyword(s):  
Meiotic Drive ◽  
Sex Bias ◽  
Z Chromosome ◽  
Female Development ◽  
Pcr Assay ◽  
Interphase Nuclei ◽  
Diverse Range ◽  
Selfish Genetic Elements ◽  
Combined Action ◽  
Quantitative Pcr Assay

Arthropod sex ratios can be manipulated by a diverse range of selfish genetic elements, including maternally inherited Wolbachia bacteria. Feminization by Wolbachia is rare but has been described for Eurema mandarina butterflies . In this species, some phenotypic and functional females, thought to be ZZ genetic males, are infected with a feminizing Wolbachia strain, w Fem. Meanwhile, heterogametic WZ females are not infected with w Fem. Here, we establish a quantitative PCR assay allowing reliable sexing in three Eurema species. Against expectation, all E. mandarina females, including w Fem females, had only one Z chromosome that was paternally inherited. Observation of somatic interphase nuclei confirmed that W chromatin was absent in w Fem females, but present in females without w Fem. We conclude that the sex bias in w Fem lines is due to meiotic drive (MD) that excludes the maternal Z and thus prevents formation of ZZ males. Furthermore, w Fem lines may have lost the W chromosome or harbour a dysfunctional version, yet rely on w Fem for female development; removal of w Fem results in all-male offspring. This is the first study that demonstrates an interaction between MD and Wolbachia feminization, and it highlights endosymbionts as potentially confounding factors in MD of sex chromosomes.

scholarly journals Haptoglobin Duplicon, Hemoglobin, and Vitamin C: Analyses in the British Women’s Heart and Health Study and Caerphilly Prospective Study

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Philip A. I. Guthrie ◽  
Mohammad R. Abdollahi ◽  
Tom Gaunt ◽  
Debbie A. Lawlor ◽  
Yoav Ben-Shlomo ◽  
...  
Keyword(s):  
Vitamin C ◽  
Copy Number ◽  
Health Study ◽  
Free Hemoglobin ◽  
Pcr Assay ◽  
Partial Duplication ◽  
Haptoglobin Genotype ◽  
Haptoglobin Gene ◽  
Apparent Association ◽  
Quantitative Pcr Assay

Background. Haptoglobin acts as an antioxidant by limiting peroxidative tissue damage by free hemoglobin. The haptoglobin gene allele Hp2 comprises a 1.7 kb partial duplication. Relative to allele Hp1, Hp2 carriers form protein multimers, suboptimal for hemoglobin scavenging.Objective. To examine the association of haptoglobin genotype with a range of phenotypes, with emphasis on vitamin C and hemoglobin levels.Methods. We applied a quantitative PCR assay for the duplication junction to two population cohorts including 2747 British women and 1198 British men. We examined the association of haptoglobin duplicon copy number with hemoglobin and vitamin C and used the copy number to complete a phenome scan.Results.Hemoglobin concentrations were greater in those with Hp2,2 genotype, in women only (Hp1,1 13.45 g/dL, Hp1,2 13.49 g/dL, Hp2,2 13.61 g/dL;P=0.002), though statistically there was no evidence of a difference between the sexes (zvalue = 1.2,P=0.24). Haptoglobin genotype was not associated with vitamin C or any other phenotype in either cohort.Conclusions. Our results do not support association of haptoglobin genotype with vitamin C or with other phenotypes measured in two population cohorts. The apparent association between haptoglobin genotype and hemoglobin in the women’s cohort merits further investigation.

scholarly journals Red queen's race: rapid evolutionary dynamics of an expanding family of meiotic drive factors and their hpRNA suppressors

2021 ◽  
Author(s):  
Jeffrey Vedanayagam ◽  
Ching-Jung Lin ◽  
Eric C. Lai
Keyword(s):  
Evolutionary Dynamics ◽  
Sex Chromosome ◽  
De Novo ◽  
Independent Set ◽  
Meiotic Drive ◽  
Sperm Chromatin ◽  
Arms Races ◽  
X Chromosomes ◽  
Selfish Genetic Elements ◽  
Satellite Repeats

Meiotic drivers are a class of selfish genetic elements that are widespread across eukaryotes. Their activities are often detrimental to organismal fitness and thus trigger drive suppression to ensure fair segregation during meiosis. Accordingly, their existence is frequently hidden in genomes, and their molecular functions are little known. Here, we trace evolutionary steps that generated the Dox meiotic drive system in Drosophila simulans (Dsim), which distorts male:female balance (sex-ratio) by depleting male progeny. We show that Dox emerged via stepwise mobilization and acquisition of portions of multiple D. melanogaster genes, including the sperm chromatin packaging gene protamine. Moreover, we reveal novel Dox homologs in Dsim and massive, recent, amplification of Dox superfamily genes specifically on X chromosomes of its closest sister species D. mauritiana (Dmau) and D. sechellia (Dsech). The emergence of Dox superfamily genes is tightly associated with 1.688 family satellite repeats that flank de novo genomic copies. In concert, we find coordinated emergence and diversification of autosomal hairpin RNA/siRNAs loci that target subsets of Dox superfamily genes across simulans clade species. Finally, an independent set of protamine amplifications the Y chromosome of D. melanogaster indicates that protamine genes are frequent and recurrent players in sex chromosome dynamics. Overall, we reveal fierce genetic arms races between meiotic drive factors and siRNA suppressors associated with recent speciation.

scholarly journals MULTIPLE MEIOTIC DRIVE SYSTEMS IN THE DROSOPHILA MELANOGASTER MALE

Genetics ◽  
1972 ◽  
Vol 72 (1) ◽  
pp. 105-115
Author(s):  
George L Gabor Miklos ◽  
Armon F Yanders ◽  
W J Peacock
Keyword(s):  
Drosophila Melanogaster ◽  
Survival Probability ◽  
Sex Chromosome ◽  
Meiotic Drive ◽  
The Other ◽  
Segregation Distorter ◽  
Two Systems ◽  
Combined Action ◽  
Drive Systems

ABSTRACT The behaviour of two "meiotic drive" systems, Segregation-Distorter (SD) and the sex chromosome sc4sc8 has been examined in the same meiocyte. It has been found that the two systems interact in a specific way. When the distorting effects of SD and sc4sc8 are against each other, there is no detectable interaction. Each system is apparently oblivious to the presence of the other, gametes being produced according to independence expectations. However when the affected chromosomes are at the same meiotic pole an interaction occurs; the survival probability of the gamete containing both distorted chromosomal products is increased, rather than being decreased by the combined action of two systems.

Identification and quantification of Fusarium oxysporum in planta and soil by means of an improved specific and quantitative PCR assay

2010 ◽  
Vol 46 (3) ◽  
pp. 372-382 ◽  
Author(s):  
Daniel Jiménez-Fernández ◽  
Miguel Montes-Borrego ◽  
Juan A. Navas-Cortés ◽  
Rafael M. Jiménez-Díaz ◽  
Blanca B. Landa
Keyword(s):  
Fusarium Oxysporum ◽  
Quantitative Pcr ◽  
In Planta ◽  
Pcr Assay ◽  
Quantitative Pcr Assay ◽  
Identification And Quantification
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