About this Research Topic
Mammals inherit two sets of chromosomes, one from each parent, and therefore possess two copies of each gene. For the majority of these genes, both alleles are expressed or repressed (biallelic genes), depending upon the cell type. However, a small number of genes show a monoallelic expression that can be either random or constitutive. Genomic imprinting mechanisms are an attractive example of monoallelic gene expression, since in the same cell, one of the two parental alleles is stably repressed by epigenetic modifications whereas the other allele is maintained in an active state. This allele-specific regulation is entirely dependent on whether the gene is inherited from the mother or from the father. This parent-of-origin monoallelic expression is different from random monoallelic expression of which one of the best-known example is the X-chromosome inactivation.
Much has been learned from mouse and human models about types of monoallelic expression, acquisition and maintenance of monoallelic gene expression, and developmental stages and tissue specificity of monoallelic expression. Although a deregulation of such molecular mechanisms, especially genomic imprinting, leads to human disorders and complex traits in model organisms or livestock species, most studies have targeted specific genomic regions. The recent technological revolution in multi-omics fields now allows a genome-wide overview of these biological processes and a deep investigation of atypical monoallelic gene expression in the meantime. This paves the way to a better understanding of:
(i) ancestral processes involved in the establishment of monoallelic gene expression but also the broad range of variability in tissues and developmental stages through multi-species comparisons;
(ii) connections existing between the different monoallelic-expressed genes through network analyses as it is already known for genomic imprinting;
(iii) signaling pathways and biological functions that are enriched in monoallelic gene expression;
(iv) the contribution of monoallelic gene expression in genotype-phenotype relationships through evaluation of parent-of-origin effects, for instance.
This Research Topic focuses exclusively on monoallelic gene expression and particularly genomic imprinting. We are especially interested in contributions using high-throughput approaches but also to a lesser extent more focused and targeted studies. The submissions may address (i) technological advances in methods to detect and identify monoallelic gene expression, (ii) evolutionary aspect of monoallelic gene expression, (iii) regulation mechanisms of monoallelic gene expression, or (iv) implications of imprinting and monoallelic gene expression for complex traits and disorders, developmental syndromes, and cancers. We welcome any proposition of manuscripts that would have been missed in this description but lie within the topic of monoallelic gene expression. We encourage manuscript submissions on a wide variety of studies as Review, Mini-review, Perspective, Opinion, Original Research, Methods, or General Commentary articles.
Keywords: genomic imprinting network, parental origin, monoallelic gene expression, allele-specific methylation
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