scholarly journals Convergent patterns of sex chromosome dosage compensation between lepidopteran species (WZ/ZZ) and eutherian mammals (XX/XY): insights from a moth neo-Z chromosome

2015 ◽  
Author(s):  
Liuqi Gu ◽  
James Walters ◽  
Douglas Knipple
Keyword(s):  
Dosage Compensation ◽  
Sex Chromosome ◽  
De Novo ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Z Chromosome ◽  
De Novo Transcriptome ◽  
Insect Order ◽  
Lepidopteran Species ◽  
Different Levels

In contrast to XX/XY species, Z-linked expression is overall reduced in female WZ/ZZ species compared to males or the autosomal expression. This pattern (Z<ZZ≈AA) has been consistently reported in all the WZ/ZZ taxa examined so far, with the singular exception of the insect order of Lepidoptera (moths and butterflies). However, conflicting results linger in this taxon due to discrepancies in data analyses and tissues sampled. To address this issue, we analyzed dosage compensation in the codling moth Cydia pomonella (Tortricidae) using tissues that represent different levels of sexual divergence. C. pomonella is the most basal lepidopteran species yet examined for dosage compensation and has a neo-Z chromosome resulting from an ancient Z:autosome translocation. We based our analyses on RNAseq and de novo transcriptome data from C. pomonella, as well as scrutiny into investigations of other lepidopteran species. Our evidence supports that the lepidopterans share a pattern (Z≈ZZ<AA) of dosage compensation that mirrors the eutherian mammals (X≈XX<AA). In particular, reproductive tissues appear to be exempt from dosage compensation, which helps explain the incongruence in prior reports. Furthermore, C. pomonella ancestral-Z segment exhibited a greater expression reduction than genes on the neo-Z segment, which intriguingly also reflects the differential up-regulation between the ancestral and newly-acquired X-linked genes in mammals. The insect order of Lepidoptera challenges both the classic theories regarding evolution of sex chromosome dosage compensation and the emerging view on association of dosage compensation with sexual heterogamety.

scholarly journals Sex chromosome dosage compensation in Heliconius butterflies: global yet still incomplete?

2015 ◽  
Author(s):  
James R Walters ◽  
Thomas J Hardcastle ◽  
Chris Jiggins
Keyword(s):  
Dosage Compensation ◽  
Sex Chromosome ◽  
Gene Dosage ◽  
Dosage Effect ◽  
Epigenetic Mechanism ◽  
Z Chromosome ◽  
Specific Gene ◽  
Dosage Effects ◽  
Heliconius Butterflies ◽  
The Impact

The evolution of heterogametic sex chromosome is often ? but not always ? accompanied by the evolution of dosage compensating mechanisms that mitigate the impact of sex-specific gene dosage on levels of gene expression. One emerging view of this process is that such mechanisms may only evolve in male-heterogametic (XY) species but not in female-heterogametic (ZW) species, which will consequently exhibit ?incomplete? sex chromosome dosage compensation. However, some recent results from moths suggest that Lepidoptera (moths and butterflies) may prove to be an exception to this prediction. Here we report an analysis of sex chromosome dosage compensation in Heliconius butterflies, sampling multiple individuals for several different adult tissues (head, abdomen, leg, mouth, and antennae). Methodologically, we introduce a novel application of linear mixed-effects models to assess dosage compensation, offering a unified statistical framework that can estimate effects specific to chromosome, to sex, and their interactions (i.e., a dosage effect). Our results show substantially reduced Z-linked expression relative to autosomes in both sexes, as previously observed in bombycoid moths. This observation is consistent with an increasing body of evidence that at least some species of moths and butterflies possess an epigenetic sex chromosome dosage compensating mechanism that operates by reducing Z chromosome expression in males. However, this mechanism appears to be imperfect in Heliconius, resulting in a modest dosage effect that produces an average 5-20% male-bias on the Z chromosome, depending on the tissue. Strong sex chromosome dosage effects have been previously in a pyralid moth. Thus our results reflect a mixture of previous patterns reported for Lepidoptera and bisect the emerging view that female-heterogametic ZW taxa have incomplete dosage compensation because they lack a chromosome-wide epigenetic mechanism mediating sex chromosome dosage compensation. In the case of Heliconius, sex chromosome dosage effects persist apparently despite such a mechanism. We also analyze chromosomal distributions of sex-biased genes and show an excess of male-biased and a dearth of female-biased genes on the Z chromosome relative to autosomes, consistent with predictions of sexually antagonistic evolution.

scholarly journals A chromosome-level genome assembly of Cydia pomonella provides insights into chemical ecology and insecticide resistance

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Fanghao Wan ◽  
Chuanlin Yin ◽  
Rui Tang ◽  
Maohua Chen ◽  
Qiang Wu ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Genome Assembly ◽  
Association Studies ◽  
Receptor Gene ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Invasive Pest ◽  
Z Chromosome ◽  
Genome Wide Association Studies ◽  
Chromosome Level

Abstract The codling moth Cydia pomonella, a major invasive pest of pome fruit, has spread around the globe in the last half century. We generated a chromosome-level scaffold assembly including the Z chromosome and a portion of the W chromosome. This assembly reveals the duplication of an olfactory receptor gene (OR3), which we demonstrate enhances the ability of C. pomonella to exploit kairomones and pheromones in locating both host plants and mates. Genome-wide association studies contrasting insecticide-resistant and susceptible strains identify hundreds of single nucleotide polymorphisms (SNPs) potentially associated with insecticide resistance, including three SNPs found in the promoter of CYP6B2. RNAi knockdown of CYP6B2 increases C. pomonella sensitivity to two insecticides, deltamethrin and azinphos methyl. The high-quality genome assembly of C. pomonella informs the genetic basis of its invasiveness, suggesting the codling moth has distinctive capabilities and adaptive potential that may explain its worldwide expansion.

scholarly journals Epigenetic mechanisms of partial dosage compensation in an avian, female heterogametic system

2021 ◽  
Author(s):  
Ana Catalan ◽  
Jochen Wolf ◽  
Justin Merondun ◽  
Ulrich Knief
Keyword(s):  
Gene Expression ◽  
Dosage Compensation ◽  
Sex Chromosome ◽  
Gene Dosage ◽  
Common Garden ◽  
Underlying Mechanism ◽  
Chromatin Accessibility ◽  
Z Chromosome ◽  
Open Chromatin ◽  
Epigenetic Mechanisms

The evolution of genetic sex determination is often accompanied by degradation of one of the proto sex chromosomes. Male heterogametic systems have evolved convergent, epigenetic mechanisms restoring the resulting imbalance in gene dosage between diploid autosomes (AA) and the hemizygous sex chromosome (X). Female heterogametic systems (AAf ZWf, AAm ZZm) tend to only show partial dosage compensation (0.5 < Zf:AAf < 1) and dosage balance (0.5<Zf:ZZm<1). The underlying mechanism remains largely elusive. Here, we quantified gene expression for a total of 15 male and female Eurasian crows (Corvus (corone) spp.) raised under common garden conditions. In addition, we characterized aspects of the regulatory landscape quantifying genome-wide ATAC-seq and 5mC methylation profiles. Partial dosage compensation was explained by female upregulation of Z-linked genes accompanied by increased chromatin accessibility on the female Z chromosome. 5mC methylation was strongly reduced in open chromatin-regions and GC islands and showed chromosome-, but no sex-specific variation. With the exception of the pseudo-autosomal region (PAR), female upregulation of gene expression was evenly spread across the Z chromosome without evidence for regional epigenetic regulation, as has for example been suggested for the male hypermethylated region (MHM) in chicken. Our results support the hypothesis that partial dosage compensation in female heterogametic systems is subject to chromosome-wide, epigenetic control mediated by differential chromatin accessibility between the sexes.

The results of field trials of the codling moth pheromone preparations in 2020

2020 ◽  
Author(s):  
S.V. Dmitriyeva ◽  
◽  
I.M. Mityushev
Keyword(s):  
Russian Federation ◽  
Central Region ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Field Trials ◽  
Field Screening ◽  
Tube Type ◽  
The Russian Federation ◽  
Polyethylene Dispenser

This article presents the results of field screening of pheromone preparations of the codling moth, Cydia pomonella L., conducted in 2020 under conditions of the Central Region of the Russian Federation. The new «Tube» type dispensers were tested vs. standard foil-polyethylene dispenser.

Sign in / Sign up

Export Citation Format

Share Document