scholarly journals The Impact of Gene Expression Regulation on Evolution of Extracellular Signaling Pathways

2010 ◽  
Vol 9 (12) ◽  
pp. 2666-2677 ◽  
Author(s):  
Varodom Charoensawan ◽  
Boris Adryan ◽  
Stephen Martin ◽  
Christian Söllner ◽  
Bernard Thisse ◽  
...  
2021 ◽  
Author(s):  
Carlos A. Villarroel ◽  
Paulo Canessa ◽  
Macarena Bastias ◽  
Francisco A Cubillos

Saccharomyces cerevisiae rewires its transcriptional output to survive stressful environments, such as nitrogen scarcity under fermentative conditions. Although divergence in nitrogen metabolism has been described among natural yeast populations, the impact of regulatory genetic variants modulating gene expression and nitrogen consumption remains to be investigated. Here, we employed an F1 hybrid from two contrasting S. cerevisiae strains, providing a controlled genetic environment to map cis factors involved in the divergence of gene expression regulation in response to nitrogen scarcity. We used a dual approach to obtain genome-wide allele-specific profiles of chromatin accessibility, transcription factor binding, and gene expression through ATAC-seq and RNA-seq. We observed large variability in allele-specific expression and accessibility between the two genetic backgrounds, with a third of these differences specific to a deficient nitrogen environment. Furthermore, we discovered events of allelic bias in gene expression correlating with allelic bias in transcription factor binding solely under nitrogen scarcity, where the majority of these transcription factors orchestrates the Nitrogen Catabolite Repression regulatory pathway and demonstrates a cis x environment-specific response. Our approach allowed us to find cis variants modulating gene expression, chromatin accessibility and allelic differences in transcription factor binding in response to low nitrogen culture conditions.


Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 69
Author(s):  
Ferdinand Nanfack-Minkeu ◽  
Laura King Sirot

There is intense interest in controlling insect reproductive output. In many insect species, reproductive output is profoundly influenced by mating, including the receipt of sperm and seminal fluid molecules, through physiological and behavior changes. To understand these changes, many researchers have investigated post-mating gene expression regulation. In this review, we synthesize information from studies both across and within different species about the impact of mating, or components of mating, on female gene expression patterns. We found that genes related to the roles of metabolism, immune-response, and chemosensation are regulated by mating across many different insect species. We highlight the few studies that have taken the important next step of examining the functional consequences of gene expression regulation which is crucial in order to understand the mechanisms underlying the mating-regulated control of female lifespan and reproduction and to make use of such knowledge to propagate or control insect populations. The potential of cross-study comparisons is diminished by different studies using different methods. Thus, we also include a consideration of how future studies could be designed to facilitate cross-study comparisons and a call for collaboration across researchers studying different insect species and different aspects of insect biology.


2021 ◽  
Author(s):  
Alex RJ Lima ◽  
Saloe B Poubel ◽  
Juliana N Roson ◽  
Loyze PO de Lima ◽  
Hellida M Costa-Silva ◽  
...  

Background: Genomic organization and gene expression regulation in trypanosomes are remarkable because protein-coding genes are organized into codirectional gene clusters with unrelated functions. Moreover, there is no dedicated promoter for each gene, resulting in polycistronic gene transcription, with posttranscriptional control playing a major role. Nonetheless, these parasites harbor epigenetic modifications at critical regulatory genome features that dynamically change among parasite stages, which are not fully understood. Results: Here, we investigated the impact of chromatin changes in a scenario commanded by posttranscriptional control exploring the parasite Trypanosoma cruzi and its differentiation program using genome-wide approaches supported by transmission electron microscopy. The integration of FAIRE and MNase-seq data, two complementary epigenomic approaches, enabled us to identify differences in T. cruzi genome compartments, putative transcriptional start regions and virulence factors. In addition, we also detected developmental chromatin regulation at tRNA loci (tDNA), which seems to be linked to the translation regulatory mechanism required for parasite differentiation. Strikingly, a positive correlation was observed between active chromatin and steady-state transcription levels. Conclusion: Taken together, our results indicate that chromatin changes reflect the unusual gene expression regulation of trypanosomes and the differences among parasite developmental stages, even in the context of a lack of canonical transcriptional control of protein-coding genes.


2021 ◽  
Author(s):  
Alex RJ Lima ◽  
Saloe B Poubel ◽  
Juliana N Rosón ◽  
Loyze PO de Lima ◽  
Hellida M Costa-Silva ◽  
...  

Abstract Background: Genomic organization and gene expression regulation in trypanosomes are remarkable because protein-coding genes are organized into codirectional gene clusters with unrelated functions. Moreover, there is no dedicated promoter for each gene, resulting in polycistronic gene transcription, with posttranscriptional control playing a major role. Nonetheless, these parasites harbor epigenetic modifications at critical regulatory genome features that dynamically change among parasite stages, which are not fully understood. Results: Here, we investigated the impact of chromatin changes in a scenario commanded by posttranscriptional control exploring the parasite Trypanosoma cruzi and its differentiation program using genome-wide approaches supported by transmission electron microscopy. The integration of FAIRE and MNase-seq data, two complementary epigenomic approaches, enabled us to identify differences in T. cruzi genome compartments, putative transcriptional start regions and virulence factors. In addition, we also detected developmental chromatin regulation at tRNA loci (tDNA), which seems to be linked to the translation regulatory mechanism required for parasite differentiation. Strikingly, a positive correlation was observed between active chromatin and steady-state transcription levels. Conclusion: Taken together, our results indicate that chromatin changes reflect the unusual gene expression regulation of trypanosomes and the differences among parasite developmental stages, even in the context of a lack of canonical transcriptional control of protein-coding genes.


2021 ◽  
Vol 16 ◽  
Author(s):  
Min Yao ◽  
Caiyun Jiang ◽  
Chenglong Li ◽  
Yongxia Li ◽  
Shan Jiang ◽  
...  

Background: Mammalian genes are regulated at the transcriptional and post-transcriptional levels. These mechanisms may involve the direct promotion or inhibition of transcription via a regulator or post-transcriptional regulation through factors such as micro (mi)RNAs. Objective: This study aimed to construct gene regulation relationships modulated by causality inference-based miRNA-(transition factor)-(target gene) networks and analyze gene expression data to identify gene expression regulators. Methods: Mouse gene expression regulation relationships were manually curated from literature using a text mining method which was then employed to generate miRNA-(transition factor)-(target gene) networks. An algorithm was then introduced to identify gene expression regulators from transcriptome profiling data by applying enrichment analysis to these networks. Results: A total of 22,271 mouse gene expression regulation relationships were curated for 4,018 genes and 242 miRNAs. GEREA software was developed to perform the integrated analyses. We applied the algorithm to transcriptome data for synthetic miR-155 oligo-treated mouse CD4+ T-cells and confirmed that miR-155 is an important network regulator. The software was also tested on publicly available transcriptional profiling data for Salmonella infection, resulting in the identification of miR-125b as an important regulator. Conclusion: The causality inference-based miRNA-(transition factor)-(target gene) networks serve as a novel resource for gene expression regulation research, and GEREA is an effective and useful adjunct to the currently available methods. The regulatory networks and the algorithm implemented in the GEREA software package are available under a free academic license at website : http://www.thua45.cn/gerea.


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