scholarly journals Enhanced functional divergence of duplicate genes several million years after gene duplication in the Arabidopsis lineage

2016 ◽  
Author(s):  
Kousuke Hanada ◽  
Ayumi Tezuka ◽  
Masafumi Nozawa ◽  
Yutaka Suzuki ◽  
Sumio Sugano ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Functional Divergence ◽  
Purifying Selection ◽  
Orthologous Gene ◽  
Synonymous Substitution ◽  
Duplicate Genes ◽  
Duplicated Genes ◽  
Highly Qualified ◽  
Duplication Events ◽  
Synonymous Substitution Rates

AbstractLineage-specifically duplicated genes likely contribute to the phenotypic divergence in closely related species. However, neither the frequency of duplication events nor the degree of selective pressures immediately after gene duplication is clear in the speciation process. Plants have substantially higher gene duplication rates than most other eukaryotes. Here, using Illumina short reads from Arabidopsis halleri, which has highly qualified plant genomes in close species (Brassica rapa, A. thaliana and A. lyrata), we succeeded in generating orthologous gene groups among B. rapa, A. thaliana, A. lyrata and A. halleri. The frequency of duplication events in the Arabidopsis lineage was approximately 10 times higher than the frequency inferred by comparative genomics of Arabidopsis, poplar, rice and moss. Of the currently retained genes in A. halleri, 11–24% had undergone gene duplication in the Arabidopsis lineage. To examine the degree of selective pressure for duplicated genes, we calculated the ratios of nonsynonymous to synonymous substitution rates (KA/KS) in the A. halleri-lyrata and A. halleri lineages. Using a maximum-likelihood framework, we examined positive (KA/KS > 1) and purifying selection (KA/KS < 1) at a significant level (P < 0.01). Duplicate genes tended to have a higher proportion of positive selection compared with non-duplicated genes. More interestingly, we found that functional divergence of duplicated genes was accelerated several million years after gene duplication at a higher proportion than immediately after gene duplication.

scholarly journals Molecular Evolution of the Vertebrate FK506 Binding Protein 25

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fei Liu ◽  
Xiao-Long Wei ◽  
Hao Li ◽  
Ji-Fu Wei ◽  
Yong-Qing Wang ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Nuclear Dna ◽  
Purifying Selection ◽  
Synonymous Substitution ◽  
Vertebrate Lineage ◽  
Gene Splicing ◽  
Fk506 Binding Protein ◽  
Ppiase Domain ◽  
Synonymous Substitution Rates ◽  
Peptidyl Prolyl Isomerases

FK506 binding proteins (FKBPs) belong to immunophilins with peptidyl-prolyl isomerases (PPIases) activity. FKBP25 (also known as FKBP3) is one of the nuclear DNA-binding proteins in the FKBPs family, which plays an important role in regulating transcription and chromatin structure. The calculation of nonsynonymous and synonymous substitution rates suggested that FKBP25 undergoes purifying selection throughout the whole vertebrate evolution. Moreover, the result of site-specific tests showed that no sites were detected under positive selection. Only one PPIase domain was detected by searching FKBP25 sequences at Pfam and SMART domain databases. Mammalian FKBP25 possess exon-intron conservation, although conservation in the whole vertebrate lineage is incomplete. The result of this study suggests that the purifying selection triggers FKBP25 evolutionary history, which allows us to discover the complete role of the PPIase domain in the interaction between FKBP25 and nuclear proteins. Moreover, intron alterations during FKBP25 evolution that regulate gene splicing may be involved in the purifying selection.

scholarly journals Genetic Diversity in the 3′ Terminal 4.7-kb Region of Grapevine leafroll-associated virus 3

2011 ◽  
Vol 101 (4) ◽  
pp. 445-450 ◽  
Author(s):  
Jinbo Wang ◽  
Abhineet M. Sharma ◽  
Siobain Duffy ◽  
Rodrigo P. P. Almeida
Keyword(s):  
Genetic Diversity ◽  
Purifying Selection ◽  
Synonymous Substitution ◽  
Effective Population ◽  
Data Set ◽  
Reading Frame ◽  
Napa Valley ◽  
Synonymous Substitution Rates ◽  
Leafroll Disease

Grapevine leafroll-associated virus 3 (GLRaV-3; Ampelovirus, Closteroviridae), associated with grapevine leafroll disease, is an important pathogen found across all major grape-growing regions of the world. The genetic diversity of GLRaV-3 in Napa Valley, CA, was studied by sequencing 4.7 kb in the 3′ terminal region of 50 isolates obtained from Vitis vinifera ‘Merlot’. GLRaV-3 isolates were subdivided into four distinct phylogenetic clades. No evidence of positive selection was observed in the data set, although neutral selection (ratio of nonsynonymous to synonymous substitution rates = 1.1) was observed in one open reading frame (ORF 11, p4). Additionally, the four clades had variable degrees of overall nucleotide diversity. Moreover, no geographical structure among isolates was observed, and isolates belonging to different phylogenetic clades were found in distinct vineyards, with one exception. Considered with the evidence of purifying selection (i.e., against deleterious mutations), these data indicate that the population of GLRaV-3 in Napa Valley is not expanding and its effective population size is not increasing. Furthermore, research on the biological characterization of GLRaV-3 strains might provide valuable insights on the biology of this species that may have epidemiological relevance.

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 Evolutionary Rate Heterogeneity and Functional Divergence of Orthologous Genes in Pyrus

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 490 ◽  
Author(s):  
Yunpeng Cao ◽  
Lan Jiang ◽  
Lihu Wang ◽  
Yongping Cai
Keyword(s):  
Expression Profiles ◽  
Functional Divergence ◽  
Expression Patterns ◽  
Synonymous Substitution ◽  
Evolutionary Rates ◽  
Orthologous Genes ◽  
Protein Coding ◽  
Different Types ◽  
Synonymous Substitution Rates ◽  
Gene Structures

Negatively selected genes (NSGs) and positively selected genes (PSGs) are the two types of most nuclear protein-coding genes in organisms. However, the evolutionary rates and characteristics of different types of genes have been rarely understood. In the present study, we investigate the rates of synonymous substitution (Ks) and the rates of non-synonymous substitution (Ka) by comparing the orthologous genes of two sequenced Pyrus species, Pyrus bretschneideri and Pyrus communis. Subsequently, we compared the evolutionary rates, gene structures, and expression profiles during different fruit development between PSGs and NSGs. Compared with the NSGs, the PSGs have fewer exons, shorter gene length, lower synonymous substitution rates and have higher evolutionary rates. Remarkably, gene expression patterns between two Pyrus species fruit indicated functional divergence for most of the orthologous genes derived from a common ancestor, and subfunctionalization for some of them. Overall, the present study shows that PSGs differs from NSGs not only under environmental selective pressure (Ka/Ks), but also in their structural, functional, and evolutionary properties. Additionally, our resulting data provides important insights for the evolution and highlights the diversification of orthologous genes in two Pyrus species.

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.

scholarly journals Molecular Evolution and Characterization of Fish Stathmin Genes

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1328
Author(s):  
Jun Cao ◽  
Xiuzhu Cheng
Keyword(s):  
Signal Transduction ◽  
Cell Proliferation ◽  
Functional Divergence ◽  
Purifying Selection ◽  
Biological Processes ◽  
Duplicated Genes ◽  
Network Analyses ◽  
Pesticide Stress ◽  
Intron Structure

Stathmin is a highly conserved microtubule remodeling protein, involved in many biological processes such as signal transduction, cell proliferation, neurogenesis and so on. However, little evolutional information has been reported about this gene family in fish. In this study, 175 stathmin genes were identified in 27 species of fish. Conserved exon-intron structure and motif distributions were found in each group. Divergence of duplicated genes implied the species’ adaptation to the environment. Functional divergence suggested that the evolution of stathmin is mainly influenced by purifying selection, and some residues may undergo positive selection. Moreover, synteny relationship near the stathmin locus was relatively conserved in some fish. Network analyses also exhibited 74 interactions, implying functional diversity. The expression pattern of some stathmin genes was also investigated under pesticide stress. These will provide useful references for their functional research in the future.

scholarly journals Genome-Wide Identification and Characterization of the PERK Gene Family in Gossypium hirsutum Reveals Gene Duplication and Functional Divergence

2019 ◽  
Vol 20 (7) ◽  
pp. 1750 ◽  
Author(s):  
Ghulam Qanmber ◽  
Ji Liu ◽  
Daoqian Yu ◽  
Zhao Liu ◽  
Lili Lu ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Gene Family ◽  
Plant Species ◽  
Functional Divergence ◽  
Rapid Evolution ◽  
Purifying Selection ◽  
Gene Families ◽  
Promoter Regions ◽  
Large Gene ◽  
Receptor Kinases

Proline-rich extensin-like receptor kinases (PERKs) are an important class of receptor kinases in plants. Receptor kinases comprise large gene families in many plant species, including the 15 PERK genes in Arabidopsis. At present, there is no comprehensive published study of PERK genes in G. hirsutum. Our study identified 33 PERK genes in G. hirsutum. Phylogenetic analysis of conserved PERK protein sequences from 15 plant species grouped them into four well defined clades. The GhPERK gene family is an evolutionarily advanced gene family that lost its introns over time. Several cis-elements were identified in the promoter regions of the GhPERK genes that are important in regulating growth, development, light responses and the response to several stresses. In addition, we found evidence for gene loss or addition through segmental or whole genome duplication in cotton. Gene duplication and synteny analysis identified 149 orthologous/paralogous gene pairs. Ka/Ks values show that most GhPERK genes experienced strong purifying selection during the rapid evolution of the gene family. GhPERK genes showed high expression levels in leaves and during ovule development. Furthermore, the expression of GhPERK genes can be regulated by abiotic stresses and phytohormone treatments. Additionally, PERK genes could be involved in several molecular, biological and physiological processes that might be the result of functional divergence.

scholarly journals A comparison of one-rate and two-rate inference frameworks for site-specific dN/dS estimation

2015 ◽  
Author(s):  
Stephanie J. Spielman ◽  
Suyang Wan ◽  
Claus O. Wilke
Keyword(s):  
Model Misspecification ◽  
Purifying Selection ◽  
Synonymous Substitution ◽  
Selective Constraint ◽  
Model Specification ◽  
Inference Model ◽  
Specific Context ◽  
Point Estimates ◽  
Synonymous Substitution Rates ◽  
Excessive Noise

AbstractTwo broad paradigms exist for inferring dN/dS, the ratio of nonsynonymous to synonymous substitution rates, from coding sequences: i) a one-rate approach, where dN/dS is represented with a single parameter, or ii) a two-rate approach, where dN and dS are estimated separately. The performances of these two approaches have been well-studied in the specific context of proper model specification, i.e. when the inference model matches the simulation model. By contrast, the relative performances of one-rate vs. two-rate parameterizations when applied to data generated according to a different mechanism remains unclear. Here, we compare the relative merits of one-rate and two-rate approaches in the specific context of model misspecification by simulating alignments with mutation-selection models rather than with dN/dS-based models. We find that one-rate frameworks generally infer more accurate dN/dS point estimates, even when dS varies among sites. In other words, modeling dS variation may substantially reduce accuracy of dN/dS point estimates. These results appear to depend on the selective constraint operating at a given site. In particular, for sites under strong purifying selection (dN/dS<~0.3), one-rate and two-rate models show comparable performances. However, one-rate models significantly outperform two-rate models for sites under moderate-to-weak purifying selection. We attribute this distinction to the fact that, for these more quickly evolving sites, a given substitution is more likely to be nonsynonymous than synonymous. The data will therefore be relatively enriched for nonsynonymous changes, and modeling dS contributes excessive noise to dN/dS estimates. We additionally find that high levels of divergence among sequences, rather than the number of sequences in the alignment, are more critical for obtaining precise point estimates.

scholarly journals Gene Duplication in the Honeybee: Patterns of DNA Methylation, Gene Expression, and Genomic Environment

2020 ◽  
Vol 37 (8) ◽  
pp. 2322-2331
Author(s):  
Carl J Dyson ◽  
Michael A D Goodisman
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Gene Duplication ◽  
Critical Role ◽  
Single Copy ◽  
Raw Material ◽  
Duplicate Genes ◽  
Gene Body ◽  
Duplicated Genes ◽  
Gene Body Methylation

Abstract Gene duplication serves a critical role in evolutionary adaptation by providing genetic raw material to the genome. The evolution of duplicated genes may be influenced by epigenetic processes such as DNA methylation, which affects gene function in some taxa. However, the manner in which DNA methylation affects duplicated genes is not well understood. We studied duplicated genes in the honeybee Apis mellifera, an insect with a highly sophisticated social structure, to investigate whether DNA methylation was associated with gene duplication and genic evolution. We found that levels of gene body methylation were significantly lower in duplicate genes than in single-copy genes, implicating a possible role of DNA methylation in postduplication gene maintenance. Additionally, we discovered associations of gene body methylation with the location, length, and time since divergence of paralogous genes. We also found that divergence in DNA methylation was associated with divergence in gene expression in paralogs, although the relationship was not completely consistent with a direct link between DNA methylation and gene expression. Overall, our results provide further insight into genic methylation and how its association with duplicate genes might facilitate evolutionary processes and adaptation.

scholarly journals Genome-wide systematic characterization of the HAK/KUP/KT gene family and its expression profile during plant growth and in response to low-K+ stress in Saccharum

2019 ◽  
Author(s):  
Xiaomin Feng ◽  
Yongjun Wang ◽  
Nannan Zhang ◽  
Zilin Wu ◽  
Qiaoying Zeng ◽  
...  
Keyword(s):  
Gene Family ◽  
Developmental Stages ◽  
Expression Patterns ◽  
Divergence Time ◽  
Purifying Selection ◽  
Synonymous Substitution ◽  
Duplication Events ◽  
Gene Structures ◽  
Gain Loss ◽  
Low K

Abstract Background: Plant genomes contain a large number of HAK/KUP/KT transporters, which play important roles in potassium uptake and translocation, osmotic potential regulation, salt tolerance, root morphogenesis and plant development. Potassium deficiency in the soil of a sugarcane planting area is serious. However, the HAK/KUP/KT gene family remains to be characterized in sugarcane (Saccharum). Results: In this study, 30 HAK/KUP/KT genes were identified in Saccharum spontaneum. Phylogenetics, duplication events, gene structures and expression patterns were analyzed. Phylogenetic analysis of the HAK/KUP/KT genes from 15 representative plants showed that this gene family is divided into four groups (clades I-IV). Both ancient whole-genome duplication (WGD) and recent gene duplication contributed to the expansion of the HAK/KUP/KT gene family. Nonsynonymous to synonymous substitution ratio (Ka/Ks) analysis showed that purifying selection was the main force driving the evolution of HAK/KUP/KT genes. The divergence time of the HAK/KUP/KT gene family was estimated to range from 134.8 to 233.7 Mya based on Ks analysis, suggesting that it is an ancient gene family in plants. Gene structure analysis showed that the HAK/KUP/KT genes were accompanied by intron gain/loss in the process of evolution. RNA-seq data analysis demonstrated that the HAK/KUP/KT genes from clades II and III were mainly constitutively expressed in various tissues, while most genes from clades I and IV had no or very low expression in the tested tissues at different developmental stages. The expression of SsHAK1 and SsHAK21 was upregulated in response to low-K+ stress. Yeast functional complementation analysis revealed that SsHAK1 and SsHAK21 could rescue K+ uptake in a yeast mutant. Conclusions: This study provided insights into the evolutionary history of HAK/KUP/KT genes. HAK7/9/18 were mainly expressed in the upper photosynthetic zone and mature zone of the stem. HAK7/9/18/25 were regulated by sunlight. SsHAK1 and SsHAK21 played important roles in mediating potassium acquisition under limited K+ supply. Our results provide valuable information and key candidate genes for further studies on the function of HAK/KUP/KT genes in Saccharum. Keywords: Saccharum, HAK/KUP/KT, evolution, gene expression, low-K+ stress

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