scholarly journals Contribution of Retrotransposition to Developmental Disorders

2018 ◽  
Author(s):  
Eugene J. Gardner ◽  
Elena Prigmore ◽  
Giuseppe Gallone ◽  
Petr Danecek ◽  
Kaitlin E. Samocha ◽  
...  

AbstractMobile genetic Elements (MEs) are segments of DNA which, through an RNA intermediate, can generate new copies of themselves and other transcribed sequences through the process of retrotransposition (RT). In humans several disorders have been attributed to RT, but the role of RT in severe developmental disorders (DD) has not yet been explored. As such, we have identified RT-derived events in 9,738 exome sequenced trios with DD-affected probands as part of the Deciphering Developmental Disorders (DDD) study. We have ascertained 9 de novo MEs, 4 of which are likely causative of the patient’s symptoms (0.04% of probands), as well as 2 de novo gene retroduplications. Beyond identifying likely diagnostic RT events, we have estimated genome-wide germline ME mutagenesis and constraint and demonstrated that coding RT events have signatures of purifying selection equivalent to those of truncating mutations. Overall, our analysis represents a comprehensive interrogation of the impact of retrotransposition on protein coding genes and a framework for future evolutionary and disease studies.

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Eugene J. Gardner ◽  
Elena Prigmore ◽  
Giuseppe Gallone ◽  
Petr Danecek ◽  
Kaitlin E. Samocha ◽  
...  

Abstract Mobile genetic Elements (MEs) are segments of DNA which can copy themselves and other transcribed sequences through the process of retrotransposition (RT). In humans several disorders have been attributed to RT, but the role of RT in severe developmental disorders (DD) has not yet been explored. Here we identify RT-derived events in 9738 exome sequenced trios with DD-affected probands. We ascertain 9 de novo MEs, 4 of which are likely causative of the patient’s symptoms (0.04%), as well as 2 de novo gene retroduplications. Beyond identifying likely diagnostic RT events, we estimate genome-wide germline ME mutation rate and selective constraint and demonstrate that coding RT events have signatures of purifying selection equivalent to those of truncating mutations. Overall, our analysis represents a comprehensive interrogation of the impact of retrotransposition on protein coding genes and a framework for future evolutionary and disease studies.


2019 ◽  
Author(s):  
Joanna Kaplanis ◽  
Kaitlin E. Samocha ◽  
Laurens Wiel ◽  
Zhancheng Zhang ◽  
Kevin J. Arvai ◽  
...  

SummaryDe novo mutations (DNMs) in protein-coding genes are a well-established cause of developmental disorders (DD). However, known DD-associated genes only account for a minority of the observed excess of such DNMs. To identify novel DD-associated genes, we integrated healthcare and research exome sequences on 31,058 DD parent-offspring trios, and developed a simulation-based statistical test to identify gene-specific enrichments of DNMs. We identified 285 significantly DD-associated genes, including 28 not previously robustly associated with DDs. Despite detecting more DD-associated genes than in any previous study, much of the excess of DNMs of protein-coding genes remains unaccounted for. Modelling suggests that over 1,000 novel DD-associated genes await discovery, many of which are likely to be less penetrant than the currently known genes. Research access to clinical diagnostic datasets will be critical for completing the map of dominant DDs.


mBio ◽  
2013 ◽  
Vol 4 (6) ◽  
Author(s):  
Cristel Archambaud ◽  
Odile Sismeiro ◽  
Joern Toedling ◽  
Guillaume Soubigou ◽  
Christophe Bécavin ◽  
...  

ABSTRACT The intestinal tract is the largest reservoir of microbes in the human body. The intestinal microbiota is thought to be able to modulate alterations of the gut induced by enteropathogens, thereby maintaining homeostasis. Listeria monocytogenes is the agent of listeriosis, an infection transmitted to humans upon ingestion of contaminated food. Crossing of the intestinal barrier is a critical step of the infection before dissemination into deeper organs. Here, we investigated the role of the intestinal microbiota in the regulation of host protein-coding genes and microRNA (miRNA or miR) expression during Listeria infection. We first established the intestinal miRNA signatures corresponding to the 10 most highly expressed miRNAs in the murine ileum of conventional and germfree mice, noninfected and infected with Listeria. Next, we identified 6 miRNAs whose expression decreased upon Listeria infection in conventional mice. Strikingly, five of these miRNA expression variations (in miR-143, miR-148a, miR-200b, miR-200c, and miR-378) were dependent on the presence of the microbiota. In addition, as is already known, protein-coding genes were highly affected by infection in both conventional and germfree mice. By crossing bioinformatically the predicted targets of the miRNAs to our whole-genome transcriptomic data, we revealed an miRNA-mRNA network that suggested miRNA-mediated global regulation during intestinal infection. Other recent studies have revealed an miRNA response to either bacterial pathogens or commensal bacteria. In contrast, our work provides an unprecedented insight into the impact of the intestinal microbiota on host transcriptional reprogramming during infection by a human pathogen. IMPORTANCE While the crucial role of miRNAs in regulating the host response to bacterial infection is increasingly recognized, the involvement of the intestinal microbiota in the regulation of miRNA expression has not been explored in detail. Here, we investigated the impact of the intestinal microbiota on the regulation of protein-coding genes and miRNA expression in a host infected by L. monocytogenes, a food-borne pathogen. We show that the microbiota interferes with the microRNA response upon oral Listeria infection and identify several protein-coding target genes whose expression correlates inversely with that of the miRNA. Further investigations of the regulatory networks involving miR-143, miR-148a, miR-200b, miR-200c, and miR-378 will provide new insights into the impact of the intestinal microbiota on the host upon bacterial infection.


2021 ◽  
Author(s):  
Noah Dukler ◽  
Mehreen R Mughal ◽  
Ritika Ramani ◽  
Yi-Fei Huang ◽  
Adam Siepel

Genome sequencing of tens of thousands of human individuals has recently enabled the measurement of large selective effects for mutations to protein-coding genes. Here we describe a new method, called ExtRaINSIGHT, for measuring similar selective effects at individual sites in noncoding as well as in coding regions of the human genome. ExtRaINSIGHT estimates the prevalance of strong purifying selection, or "ultraselection" (λs), as the fractional depletion of rare single-nucleotide variants (minor allele frequency <0.1%) in a target set of genomic sites relative to matched sites that are putatively neutrally evolving, in a manner that controls for local variation and neighbor-dependence in mutation rate. We show using simulations that, above an appropriate threshold, λs is closely related to the average site-specific selection coefficient against heterozygous point mutations, as predicted at mutation-selection balance. Applying ExtRaINSIGHT to 71,702 whole genome sequences from gnomAD v3, we find particularly strong evidence of ultraselection in evolutionarily ancient miRNAs and neuronal protein-coding genes, as well as at splice sites. Moreover, our estimated selection coefficient against heterozygous amino-acid replacements across the genome (at 1.4%) is substantially larger than previous estimates based on smaller sample sizes. By contrast, we find weak evidence of ultraselection in other noncoding RNAs and transcription factor binding sites, and only modest evidence in ultraconserved elements and human accelerated regions. We estimate that ~0.3-0.5% of the human genome is ultraselected, with one third to one half of ultraselected sites falling in coding regions. These estimates suggest ~0.3-0.4 lethal or nearly lethal de novo mutations per potential human zygote, together with ~2 de novo mutations that are more weakly deleterious. Overall, our study sheds new light on the genome-wide distribution of fitness effects for new point mutations by combining deep new sequencing data sets and classical theory from population genetics.


2020 ◽  
Author(s):  
Laura Natalia Balarezo-Cisneros ◽  
Steven Parker ◽  
Marcin G Fraczek ◽  
Soukaina Timouma ◽  
Ping Wang ◽  
...  

AbstractNon-coding RNAs (ncRNAs), including the more recently identified Stable Unannotated Transcripts (SUTs) and Cryptic Unstable Transcripts (CUTs), are increasingly being shown to play pivotal roles in the transcriptional and post-transcriptional regulation of genes in eukaryotes. Here, we carried out a large-scale screening of ncRNAs in Saccharomyces cerevisiae, and provide evidence for SUT and CUT function. Phenotypic data on 372 ncRNA deletion strains in 23 different growth conditions were collected, identifying ncRNAs responsible for significant cellular fitness changes. Transcriptome profiles were assembled for 18 haploid ncRNA deletion mutants and 2 essential ncRNA heterozygous deletants. Guided by the resulting RNA-seq data we analysed the genome-wide dysregulation of protein coding genes and non-coding transcripts. Novel functional ncRNAs, SUT125, SUT126, SUT035 and SUT532 that act in trans by modulating transcription factors were identified. Furthermore, we described the impact of SUTs and CUTs in modulating coding gene expression in response of different environmental conditions, regulating important biological process such as respiration (SUT125, SUT126, SUT035, SUT432), steroid biosynthesis (CUT494, SUT530, SUT468) or rRNA processing (SUT075 and snR30). Overall, this data captures and integrates the regulatory and phenotypic network of ncRNAs and protein coding genes, providing genome-wide evidence of the impact of ncRNAs on cellular homeostasis.Author SummaryThe yeast genome contains 25% of non-coding RNA molecules (ncRNAs), which do not translate into proteins but are involved in regulation of gene expression. ncRNAs can affect nearby genes by physically interfering with their transcription (cis mode of action), or they interact with DNA, proteins or others RNAs to regulate the expression of distant genes (trans mode of action). Examples of cis-acting ncRNAs have been broadly described, however genome-wide studies to identify functional trans-acting ncRNAs involved in global gene regulation are still lacking. Here, we used the ncRNA yeast deletion collection to score their impact on cellular function in different environmental conditions. A group of 20 ncRNAs mutants with broad fitness diversity were selected to investigate their effect on the protein and ncRNA expression network. We showed a high correlation between altered phenotypes and global transcriptional changes, in an environmental dependent manner. We confirmed the widespread trans acting expressional regulation of ncRNAs in the genome and their role in affecting transcription factors. These findings support the notion of the involvement on ncRNAs in fine tuning the cellular expression via regulations of TFs, as an advantageous RNA-mediated mechanism that can be fast and cost-effective for the cells.


PLoS Genetics ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. e1008761
Author(s):  
Laura Natalia Balarezo-Cisneros ◽  
Steven Parker ◽  
Marcin G. Fraczek ◽  
Soukaina Timouma ◽  
Ping Wang ◽  
...  

Non-coding RNAs (ncRNAs), including the more recently identified Stable Unannotated Transcripts (SUTs) and Cryptic Unstable Transcripts (CUTs), are increasingly being shown to play pivotal roles in the transcriptional and post-transcriptional regulation of genes in eukaryotes. Here, we carried out a large-scale screening of ncRNAs in Saccharomyces cerevisiae, and provide evidence for SUT and CUT function. Phenotypic data on 372 ncRNA deletion strains in 23 different growth conditions were collected, identifying ncRNAs responsible for significant cellular fitness changes. Transcriptome profiles were assembled for 18 haploid ncRNA deletion mutants and 2 essential ncRNA heterozygous deletants. Guided by the resulting RNA-seq data we analysed the genome-wide dysregulation of protein coding genes and non-coding transcripts. Novel functional ncRNAs, SUT125, SUT126, SUT035 and SUT532 that act in trans by modulating transcription factors were identified. Furthermore, we described the impact of SUTs and CUTs in modulating coding gene expression in response to different environmental conditions, regulating important biological process such as respiration (SUT125, SUT126, SUT035, SUT432), steroid biosynthesis (CUT494, SUT053, SUT468) or rRNA processing (SUT075 and snR30). Overall, these data capture and integrate the regulatory and phenotypic network of ncRNAs and protein-coding genes, providing genome-wide evidence of the impact of ncRNAs on cellular homeostasis.


Science ◽  
2018 ◽  
Vol 362 (6419) ◽  
pp. 1161-1164 ◽  
Author(s):  
Hilary C. Martin ◽  
Wendy D. Jones ◽  
Rebecca McIntyre ◽  
Gabriela Sanchez-Andrade ◽  
Mark Sanderson ◽  
...  

We estimated the genome-wide contribution of recessive coding variation in 6040 families from the Deciphering Developmental Disorders study. The proportion of cases attributable to recessive coding variants was 3.6% in patients of European ancestry, compared with 50% explained by de novo coding mutations. It was higher (31%) in patients with Pakistani ancestry, owing to elevated autozygosity. Half of this recessive burden is attributable to known genes. We identified two genes not previously associated with recessive developmental disorders, KDM5B and EIF3F, and functionally validated them with mouse and cellular models. Our results suggest that recessive coding variants account for a small fraction of currently undiagnosed nonconsanguineous individuals, and that the role of noncoding variants, incomplete penetrance, and polygenic mechanisms need further exploration.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Liqiang Tan ◽  
Weisheng Cheng ◽  
Fang Liu ◽  
Dan Ohtan Wang ◽  
Linwei Wu ◽  
...  

Abstract Background Canonical nonsense-mediated decay (NMD) is an important splicing-dependent process for mRNA surveillance in mammals. However, processed pseudogenes are not able to trigger NMD due to their lack of introns. It is largely unknown whether they have evolved other surveillance mechanisms. Results Here, we find that the RNAs of pseudogenes, especially processed pseudogenes, have dramatically higher m6A levels than their cognate protein-coding genes, associated with de novo m6A peaks and motifs in human cells. Furthermore, pseudogenes have rapidly accumulated m6A motifs during evolution. The m6A sites of pseudogenes are evolutionarily younger than neutral sites and their m6A levels are increasing, supporting the idea that m6A on the RNAs of pseudogenes is under positive selection. We then find that the m6A RNA modification of processed, rather than unprocessed, pseudogenes promotes cytosolic RNA degradation and attenuates interference with the RNAs of their cognate protein-coding genes. We experimentally validate the m6A RNA modification of two processed pseudogenes, DSTNP2 and NAP1L4P1, which promotes the RNA degradation of both pseudogenes and their cognate protein-coding genes DSTN and NAP1L4. In addition, the m6A of DSTNP2 regulation of DSTN is partially dependent on the miRNA miR-362-5p. Conclusions Our discovery reveals a novel evolutionary role of m6A RNA modification in cleaning up the unnecessary processed pseudogene transcripts to attenuate their interference with the regulatory network of protein-coding genes.


2018 ◽  
Author(s):  
Joanna Kaplanis ◽  
Kaitlin E. Samocha ◽  
Laurens Wiel ◽  
Zhancheng Zhang ◽  
Kevin J. Arvai ◽  
...  

SummaryDe novo mutations (DNMs) in protein-coding genes are a well-established cause of developmental disorders (DD). However, known DD-associated genes only account for a minority of the observed excess of such DNMs. To identify novel DD-associated genes, we integrated healthcare and research exome sequences on 31,058 DD parent-offspring trios, and developed a simulation-based statistical test to identify gene-specific enrichments of DNMs. We identified 299 significantly DD-associated genes, including 49 not previously robustly associated with DDs. Despite detecting more DD-associated genes than in any previous study, much of the excess of DNMs of protein-coding genes remains unaccounted for. Modelling suggests that over 500 novel DD-associated genes await discovery, many of which are likely to be less penetrant than the currently known genes. Research access to clinical diagnostic datasets will be critical for completing the map of dominant DDs.


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