Topic
Dosage compensation
About: Dosage compensation is a research topic. Over the lifetime, 1920 publications have been published within this topic receiving 124589 citations.
Papers published on a yearly basis
Papers
More filters
01 Jan 1998
TL;DR: D dosage compensation of X linked genes can be considered as an evolutionary strategy required to equalize gene expression between individuals possessing different numbers of sex chromosomes for sex determination.
Abstract: One of the consequence of sex chromosome heteromorphism is that there are differences in the amount of quality of the genetic material in the two sexes. The heterogametic sex (XX and ZW in female and XY and ZZ in males) has a single dose of some genes which are present in double dose in homogametic sex. In different animal groups where precise differentiation of the sex chromosomes in the two sexes have been established, the need for dosage compensation has been followed as an obligatory consequence depending on the functional significance of the genes in the inactivated or lost segment of the Y chromosome. Thus, dosage compensation of X linked genes can be considered as an evolutionary strategy required to equalize gene expression between individuals possessing different numbers of sex chromosomes for sex determination. The phenomenon of equalization of the X linked gene products therefore acts as a factor against the selection preference for a particular sex and restores the balance for the haplo-X in the sex against the diplo-X of the other. Therefore, it is reasonable to believe that strong selection forces favour it. Exceptions are however, evident in systems where females are heterogametic, for example, ophidians, avians and Lepidopterans. The phenomenon of dosage compensation was first identified by Muller et al. (1931) in Drosophila.
4 citations
15 Jul 2014
TL;DR: As theory posits, Drosophila X-linked male-biased genes show evidence of adaptive evolution at both protein and expression levels, which may contribute to explain why the X chromosome is a hotspot for the genetic factors underlying hybrid male sterility.
Abstract: Sex chromosomes, particularly the X chromosome, play a unique role in evolution due to several distinct features In Drosophila, the X chromosome has been proposed to constitute an undesirable environment for genes expressed at higher levels in males than in females (ie male-biased genes) and, as a result, is partially demasculinized However, male-biased genes remaining on the X chromosome do not seem to be at a disadvantage relative to their autosomal counterparts Population genetic models predict that under certain conditions X-linked genes will experience more bouts of positive selection than autosomal genes, leading to faster-X evolution, particularly for male-biased genes As theory posits, Drosophila X-linked male-biased genes show evidence of adaptive evolution at both protein and expression levels This faster-X evolution has broad implications In speciation, it may contribute to explain why the X chromosome is a hotspot for the genetic factors underlying hybrid male sterility (ie the large X-effect)
Key Concepts:
Underrepresentation of X-linked male-biased genes due to unfavorable features of the X chromosome
Faster-X evolution of male-biased genes at both the protein and expression levels
Consequences of faster-X evolution include the disproportionally large effect of the X chromosome in hybrid male sterility
Keywords:
X chromosome;
sexual antagonism;
meiotic sex chromosome inactivation;
dosage compensation;
faster-X;
gene expression;
large X-effect;
speciation;
adaptive evolution;
positive selection
4 citations
TL;DR: It is argued that tuning of gene dosage is multilayered in Lepidoptera and that expression balance across chromosomal classes may predominantly be driven by enrichment of male-biased genes on the Z-chromosome and cooption of available dosage regulators.
Abstract: In species with genetic sex determination, dosage compensation can evolve to equal expression levels of sex-linked and autosomal genes. Current knowledge about dosage compensation has mainly been derived from male-heterogametic (XX/XY) model organisms, whereas less is understood about the process in female-heterogametic systems (ZZ/ZW). In moths and butterflies, downregulation of Z-linked expression in males (ZZ) to match the expression level in females (ZW) is often observed. However, little is known about the underlying regulatory mechanisms, or if dosage compensation patterns vary across ontogenetic stages. In this study, we assessed dynamics of Z-linked and autosomal expression levels across developmental stages in the wood white (Leptidea sinapis). We found that although expression of Z-linked genes in general was reduced compared with autosomal genes, dosage compensation was actually complete for some categories of genes, in particular sex-biased genes, but equalization in females was constrained to a narrower gene set. We also observed a noticeable convergence in Z-linked expression between males and females after correcting for sex-biased genes. Sex-biased expression increased successively across developmental stages, and male-biased genes were enriched on the Z-chromosome. Finally, all five core genes associated with the ribonucleoprotein dosage compensation complex male-specific lethal were detected in adult females, in correspondence with a reduction in the expression difference between autosomes and the single Z-chromosome. We show that tuning of gene dosage is multilayered in Lepidoptera and argue that expression balance across chromosomal classes may predominantly be driven by enrichment of male-biased genes on the Z-chromosome and cooption of available dosage regulators.
4 citations
TL;DR: It is found that topical application of a 20-nucleotide-long antisense DNA fragment from the death-associated inhibitor of apoptosis (DIAP)-2 gene interferes with D. melanogaster development and significantly decreases the number of female imagos and their biomass.
Abstract: Several genes have been identified to play important roles associated with sex selection in Drosophila melanogaster . An essential part is attributed to the sex-lethal gene that depends on the expression of the X:A (number of chromosomes to autosomes) ratio signal controlling both sex selection and dosage compensation processes in D. melanogaster . Interestingly, for sex selection in D. melanogaster there are no documented data addressing the role of the inhibitor of apoptosis (IAP) genes and their signaling influence on this biological process. In this study, we found that topical application of a 20-nucleotide-long antisense DNA fragment (oligoDIAP-2) from the death-associated inhibitor of apoptosis (DIAP)-2 gene interferes with D. melanogaster development and significantly decreases the number of female imagos and their biomass. We show that the applied antisense oligoDIAP-2 fragment downregulates the target DIAP-2 gene whose normal concentration is necessary for the development of female D. melanogaster . These data correspond to the results on downregulation of the target host IAP-Z gene of Lymantria dispar L. female imagos after topical treatment with an 18-nucleotide-long antisense DNA fragment from the Lymantria dispar multicapsid nuclear polyhedrosis virus IAP-3 gene at the larval stage. The observed novel phenomenon linking the downregulation of insect IAP genes and the low rate of female imago development could have practical application, especially in insect pest control and molecular pathology. https://doi.org/10.2298/ABS170302023N Received: March 2, 2017; Revised: April 29, 2017; Accepted: May 17, 2017; Published online: July 19, 2017 How to cite this article: Nyadar PM, Oberemok VV, Zubarev IV. A small molecule for a big transformation: Topical application of a 20-nucleotide-long antisense fragment of the DIAP-2 gene inhibits the development of Drosophila melanogaster female imagos. Arch Biol Sci. 2018;70(1):33-9.
4 citations
TL;DR: In this paper , the extent and nature of epigenomic changes associated with UV sexual differentiation in the brown alga Ectocarpus, a model UV system, were investigated.
Abstract: Abstract In many eukaryotes, such as dioicous mosses and many algae, sex is determined by UV sex chromosomes and is expressed during the haploid phase of the life cycle. In these species, the male and female developmental programs are initiated by the presence of the U- or V-specific regions of the sex chromosomes but, as in XY and ZW systems, sexual differentiation is largely driven by autosomal sex-biased gene expression. The mechanisms underlying the regulation of sex-biased expression of genes during sexual differentiation remain elusive. Here, we investigated the extent and nature of epigenomic changes associated with UV sexual differentiation in the brown alga Ectocarpus, a model UV system. Six histone modifications were quantified in near-isogenic lines, leading to the identification of 16 chromatin signatures across the genome. Chromatin signatures correlated with levels of gene expression and histone PTMs changes in males versus females occurred preferentially at genes involved in sex-specific pathways. Despite the absence of chromosome scale dosage compensation and the fact that UV sex chromosomes recombine across most of their length, the chromatin landscape of these chromosomes was remarkably different to that of autosomes. Hotspots of evolutionary young genes in the pseudoautosomal regions appear to drive the exceptional chromatin features of UV sex chromosomes.
4 citations