scholarly journals Analysis of Duplicate Gene Families in Microbial Genomes and Application to the Study of Gene Duplication in M. tuberculosis

10.5772/24142 ◽  
2011 ◽  
Author(s):  
Venu Vuppu ◽  
Nicola Mulder
Keyword(s):  
Gene Duplication ◽  
Duplicate Gene ◽  
Gene Families ◽  
Microbial Genomes

scholarly journals Promoter-mediated diversification of transcriptional bursting dynamics following gene duplication

2018 ◽  
Vol 115 (33) ◽  
pp. 8364-8369 ◽  
Author(s):  
Edward Tunnacliffe ◽  
Adam M. Corrigan ◽  
Jonathan R. Chubb
Keyword(s):  
Gene Duplication ◽  
Expression Profiles ◽  
Single Cells ◽  
Family Members ◽  
Gene Families ◽  
Developmental Expression ◽  
Upstream Sequence ◽  
Genomic Context ◽  
Entire Family ◽  
Transcriptional Bursting

During the evolution of gene families, functional diversification of proteins often follows gene duplication. However, many gene families expand while preserving protein sequence. Why do cells maintain multiple copies of the same gene? Here we have addressed this question for an actin family with 17 genes encoding an identical protein. The genes have divergent flanking regions and are scattered throughout the genome. Surprisingly, almost the entire family showed similar developmental expression profiles, with their expression also strongly coupled in single cells. Using live cell imaging, we show that differences in gene expression were apparent over shorter timescales, with family members displaying different transcriptional bursting dynamics. Strong “bursty” behaviors contrasted steady, more continuous activity, indicating different regulatory inputs to individual actin genes. To determine the sources of these different dynamic behaviors, we reciprocally exchanged the upstream regulatory regions of gene family members. This revealed that dynamic transcriptional behavior is directly instructed by upstream sequence, rather than features specific to genomic context. A residual minor contribution of genomic context modulates the gene OFF rate. Our data suggest promoter diversification following gene duplication could expand the range of stimuli that regulate the expression of essential genes. These observations contextualize the significance of transcriptional bursting.

scholarly journals Ancient Genome Duplications Did Not Structure the Human Hox-Bearing Chromosomes

2001 ◽  
Vol 11 (5) ◽  
pp. 771-780 ◽  
Author(s):  
Austin L. Hughes ◽  
Jack da Silva ◽  
Robert Friedman
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Duplication ◽  
Genome Duplication ◽  
Gene Families ◽  
Gene Duplications ◽  
Human Chromosomes ◽  
Time Period ◽  
Genome Duplications

The fact that there are four homeobox (Hox) clusters in most vertebrates but only one in invertebrates is often cited as evidence for the hypothesis that two rounds of genome duplication by polyploidization occurred early in vertebrate history. In addition, it has been observed in humans and other mammals that numerous gene families include paralogs on two or more of the fourHox-bearing chromosomes (the chromosomes bearing theHox clusters; i.e., human chromosomes 2, 7, 12, and 17), and the existence of these paralogs has been taken as evidence that these genes were duplicated along with the Hox clusters by polyploidization. We tested this hypothesis by phylogenetic analysis of 42 gene families including members on two or more of the humanHox-bearing chromosomes. In 32 of these families there was evidence against the hypothesis that gene duplication occurred simultaneously with duplication of the Hox clusters. Phylogenies of 14 families supported the occurrence of one or more gene duplications before the origin of vertebrates, and of 15 gene duplication times estimated for gene families evolving in a clock-like manner, only six were dated to the same time period early in vertebrate history during which the Hox clusters duplicated. Furthermore, of gene families duplicated around the same time as the Hoxclusters, the majority showed topologies inconsistent with their having duplicated simultaneously with the Hox clusters. The results thus indicate that ancient events of genome duplication, if they occurred at all, did not play an important role in structuring the mammalian Hox-bearing chromosomes.

scholarly journals Recurrent Sequence Evolution After Independent Gene Duplication

2020 ◽  
Author(s):  
Samuel Hermann Alexander Von Der Dunk ◽  
Berend Snel
Keyword(s):  
Gene Duplication ◽  
Experimental Testing ◽  
Parallel Evolution ◽  
Gene Families ◽  
Functional Differentiation ◽  
Functional Change ◽  
Neutral Evolution ◽  
Sequence Evolution ◽  
Recurrent Sequence ◽  
Independent Gene

Abstract Background Convergent and parallel evolution provide unique insights into the mechanisms of natural selection. Some of the most striking convergent and parallel (collectively recurrent ) amino acid substitutions in proteins are adaptive, but there are also many that are selectively neutral. Accordingly, genome-wide assessment has shown that recurrent sequence evolution in orthologs is chiefly explained by nearly neutral evolution. For paralogs, more frequent functional change is expected because additional copies are generally not retained if they do not acquire their own niche. Yet, it is unknown to what extent recurrent sequence differentiation is discernible after independent gene duplications in different eukaryotic taxa. Results We develop a framework that detects patterns of recurrent sequence evolution in duplicated genes. This is used to analyze the genomes of 90 diverse eukaryotes. We find a remarkable number of families with a potentially predictable functional differentiation following gene duplication. In some protein families, more than ten independent duplications show a similar sequence-level differentiation between paralogs. Based on further analysis, the sequence divergence is found to be generally asymmetric. Moreover, about 6\% of the recurrent sequence evolution between paralog pairs can be attributed to recurrent differentiation of subcellular localization. Finally, we reveal the specific recurrent patterns for the gene families Hint1/Hint2, Sco1/Sco2 and vma11/vma3. Conclusions The presented methodology provides a means to study the biochemical underpinning of functional differentiation between paralogs. For instance, two abundantly repeated substitutions are identified between independently derived Sco1 and Sco2 paralogs. Such identified substitutions allow direct experimental testing of the biological role of these residues for the repeated functional differentiation. We also uncover a diverse set of families with recurrent sequence evolution and reveal trends in the functional and evolutionary trajectories of this hitherto understudied phenomenon.

scholarly journals GeneSeqToFamily: the Ensembl Compara GeneTrees pipeline as a Galaxy workflow

2016 ◽  
Author(s):  
Anil S. Thanki ◽  
Nicola Soranzo ◽  
Wilfried Haerty ◽  
Robert P. Davey
Keyword(s):  
Gene Duplication ◽  
Structural Changes ◽  
Gene Families ◽  
Vital Role ◽  
Software Project ◽  
Command Line ◽  
Gene Trees ◽  
Ancestral Gene ◽  
The Galaxy ◽  
Duplication Events

AbstractBackgroundGene duplication is a major factor contributing to evolutionary novelty, and the contraction or expansion of gene families has often been associated with morphological, physiological and environmental adaptations. The study of homologous genes helps us to understand the evolution of gene families. It plays a vital role in finding ancestral gene duplication events as well as identifying genes that have diverged from a common ancestor under positive selection. There are various tools available, such as MSOAR, OrthoMCL and HomoloGene, to identify gene families and visualise syntenic information between species, providing an overview of syntenic regions evolution at the family level. Unfortunately, none of them provide information about structural changes within genes, such as the conservation of ancestral exon boundaries amongst multiple genomes. The Ensembl GeneTrees computational pipeline generates gene trees based on coding sequences and provides details about exon conservation, and is used in the Ensembl Compara project to discover gene families.FindingsA certain amount of expertise is required to configure and run the Ensembl Compara GeneTrees pipeline via command line. Therefore, we have converted the command line Ensembl Compara GeneTrees pipeline into a Galaxy workflow, called GeneSeqToFamily, and provided additional functionality. This workflow uses existing tools from the Galaxy ToolShed, as well as providing additional wrappers and tools that are required to run the workflow.ConclusionsGeneSeqToFamily represents the Ensembl Compara pipeline as a set of interconnected Galaxy tools, so they can be run interactively within the Galaxy’s user-friendly workflow environment while still providing the flexibility to tailor the analysis by changing configurations and tools if necessary. Additional tools allow users to subsequently visualise the gene families produced by the workflow, using the Aequatus.js interactive tool, which has been developed as part of the Aequatus software project.

scholarly journals Learning retention mechanisms and evolutionary parameters of duplicate genes from their expression data

2020 ◽  
Author(s):  
Michael DeGiorgio ◽  
Raquel Assis
Keyword(s):  
Gene Expression ◽  
Gene Duplication ◽  
Statistical Learning ◽  
Gene Evolution ◽  
Functional Divergence ◽  
Duplicate Gene ◽  
Duplicate Genes ◽  
Evolutionary Mechanisms ◽  
Retention Mechanisms ◽  
Gene Copies

AbstractLearning about the roles that duplicate genes play in the origins of novel phenotypes requires an understanding of how their functions evolve. To date, only one method—CDROM—has been developed with this goal in mind. In particular, CDROM employs gene expression distances as proxies for functional divergence, and then classifies the evolutionary mechanisms retaining duplicate genes from comparisons of these distances in a decision tree framework. However, CDROM does not account for stochastic shifts in gene expression or leverage advances in contemporary statistical learning for performing classification, nor is it capable of predicting the underlying parameters of duplicate gene evolution. Thus, here we develop CLOUD, a multi-layer neural network built upon a model of gene expression evolution that can both classify duplicate gene retention mechanisms and predict their underlying evolutionary parameters. We show that not only is the CLOUD classifier substantially more powerful and accurate than CDROM, but that it also yields accurate parameter predictions, enabling a better understanding of the specific forces driving the evolution and long-term retention of duplicate genes. Further, application of the CLOUD classifier and predictor to empirical data from Drosophila recapitulates many previous findings about gene duplication in this lineage, showing that new functions often emerge rapidly and asymmetrically in younger duplicate gene copies, and that functional divergence is driven by strong natural selection. Hence, CLOUD represents the best available method for classifying retention mechanisms and predicting evolutionary parameters of duplicate genes, thereby also highlighting the utility of incorporating sophisticated statistical learning techniques to address long-standing questions about evolution after gene duplication.

scholarly journals Characterizing Gene Copy Number of Heat Shock Protein Gene Families in the Emerald Rockcod, Trematomus bernacchii

Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 867
Author(s):  
Anthony D. Tercero ◽  
Sean P. Place
Keyword(s):  
Heat Shock ◽  
Gene Duplication ◽  
Heat Shock Proteins ◽  
Heat Shock Response ◽  
Copy Number ◽  
Gene Families ◽  
Gene Copy ◽  
Shock Response ◽  
Trematomus Bernacchii ◽  
Shock Proteins

The suborder Notothenioidae is comprised of Antarctic fishes, several of which have lost their ability to rapidly upregulate heat shock proteins in response to thermal stress, instead adopting a pattern of expression resembling constitutive genes. Given the cold-denaturing effect that sub-zero waters have on proteins, evolution in the Southern Ocean has likely selected for increased expression of molecular chaperones. These selective pressures may have also enabled retention of gene duplicates, bolstering quantitative output of cytosolic heat shock proteins (HSPs). Given that newly duplicated genes are under more relaxed selection, it is plausible that gene duplication enabled altered regulation of such highly conserved genes. To test for evidence of gene duplication, copy number of various isoforms within major heat shock gene families were characterized via qPCR and compared between the Antarctic notothen, Trematomus bernacchii, which lost the inducible heat shock response, and the non-Antarctic notothen, Notothenia angustata, which maintains an inducible heat shock response. The results indicate duplication of isoforms within the hsp70 and hsp40 super families have occurred in the genome of T. bernacchii. The findings suggest gene duplications may have been critical in maintaining protein folding efficiency in the sub-zero waters and provided an evolutionary mechanism of alternative regulation of these conserved gene families.

scholarly journals Enhanced fixation and preservation of a newly arisen duplicate gene by masking deleterious loss-of-function mutations

2009 ◽  
Vol 91 (4) ◽  
pp. 267-280 ◽  
Author(s):  
KENTARO M. TANAKA ◽  
K. RYO TAKAHASI ◽  
TOSHIYUKI TAKANO-SHIMIZU
Keyword(s):  
Gene Duplication ◽  
Gene Dosage ◽  
Purifying Selection ◽  
Duplicate Gene ◽  
Selective Advantage ◽  
Duplicate Genes ◽  
Segmental Duplications ◽  
Loss Of Function ◽  
Potential Consequence ◽  
Degree Of Dominance

SummarySegmental duplications are enriched within many eukaryote genomes, and their potential consequence is gene duplication. While previous theoretical studies of gene duplication have mainly focused on the gene silencing process after fixation, the process leading to fixation is even more important for segmental duplications, because the majority of duplications would be lost before reaching a significant frequency in a population. Here, by a series of computer simulations, we show that purifying selection against loss-of-function mutations increases the fixation probability of a new duplicate gene, especially when the gene is haplo-insufficient. Theoretically, the probability of simultaneous preservation of both duplicate genes becomes twice the loss-of-function mutation rate (uc) when the population size (N), the degree of dominance of mutations (h) and the recombination rate between the duplicate genes (c) are all sufficiently large (Nuc>1, h>0·1 and c>uc). The preservation probability declines rapidly with h and becomes 0 when h=0 (haplo-sufficiency). We infer that masking deleterious loss-of-function mutations give duplicate genes an immediate selective advantage and, together with effects of increased gene dosage, would predominantly determine the fates of the duplicate genes in the early phase of their evolution.

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