scholarly journals Comparable Rates of Gene Loss and Functional Divergence After Genome Duplications Early in Vertebrate Evolution

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1259-1266 ◽  
Author(s):  
Joseph H Nadeau ◽  
David Sankoff

Duplicated genes are an important source of new protein functions and novel developmental and physiological pathways. Whereas most models for fate of duplicated genes show that they tend to be rapidly lost, models for pathway evolution suggest that many duplicated genes rapidly acquire novel functions. Little empirical evidence is available, however, for the relative rates of gene loss vs. divergence to help resolve these contradictory expectations. Gene families resulting from genome duplications provide an opportunity to address this apparent contradiction. With genome duplication, the number of duplicated genes in a gene family is at most 2n, where n is the number of duplications. The size of each gene family, e.g., 1, 2, 3,..., 2n, reflects the patterns of gene loss vs. functional divergence after duplication. We focused on gene families in humans and mice that arose from genome duplications in early vertebrate evolution and we analyzed the frequency distribution of gene family size, i.e., the number of families with two, three or four members. All the models that we evaluated showed that duplicated genes are almost as likely to acquire a new and essential function as to be lost through acquisition of mutations that compromise protein function. An explanation for the unexpectedly high rate of functional divergence is that duplication allows genes to accumulate more neutral than disadvantageous mutations, thereby providing more opportunities to acquire diversified functions and pathways.

2020 ◽  
Author(s):  
Jennifer A. Noble ◽  
Ming-Che James Liu ◽  
Thomas A. DeFalco ◽  
Martin Stegmann ◽  
Kara McNamara ◽  
...  

AbstractA signaling complex comprising members of the LORELEI (LRE)-LIKE GPI-anchored protein (LLG) and Catharanthus roseus RECEPTOR-LIKE KINASE 1-LIKE (CrRLK1L) families perceive RAPID ALKALINIZATION FACTOR (RALF) peptides and regulate growth, development, reproduction, and immunity in Arabidopsis thaliana. Duplications in each component, which potentially could generate thousands of combinations of this signaling complex, are also evident in other angiosperms. Widespread duplication in angiosperms raises the question what evolutionary mechanisms underlie the expansion and retention of these gene families, as duplicated genes are typically rendered non-functional. As genetic and genomic resources make it a tractable model system, here we investigated this question using LLG gene family evolution and function in Brassicaceae. We first established that the LLG homologs in the Brassicaceae resulted from duplication events that pre-date the divergence of species in this family. Complementation of vegetative phenotypes in llg1 by LRE, LLG2, and LLG3 showed that the molecular functions of LLG homologs in A. thaliana are conserved. We next tested the possibility that differences in gene expression (regulatory subfunctionalization), rather than functional divergence, played a role in retention of these duplicated genes. For this, we examined the function and expression of LRE and LLG1 in A. thaliana and their single copy ortholog in Cleome violacea (Clevi LRE/LLG1), a representative species outside the Brassicaceae, but from the same order (Brassicales). We showed that expression of LLG1 and LRE did not overlap in A. thaliana and that Clevi-LRE/LLG1 expression in C. violacea encompassed all the expression domains of A. thaliana LRE + LLG1. Still, complementation experiments showed that LLG1 rescued reproductive phenotypes in lre and that Clevi LRE/LLG1 rescued both vegetative and reproductive phenotypes in llg1 and lre. Additionally, we found that expression of LLG2 and LLG3 in A. thaliana have also diverged from the expression of their corresponding single copy ortholog (Clevi LLG2/LLG3) in C. violacea. Our findings demonstrated how regulatory subfunctionalization, rather than functional divergence, underlies the retention of the LLG gene family in Brassicaceae. Our findings on the regulatory divergence and functional conservation provide an experimental framework to characterize the combinatorial assembly and function of this critical plant cell signaling complex.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1190
Author(s):  
Yuqi Huang ◽  
Minghao Sun ◽  
Lenan Zhuang ◽  
Jin He

Androgen-inducible genes (AIGs), which can be regulated by androgen level, constitute a group of genes characterized by the presence of the AIG/FAR-17a domain in its protein sequence. Previous studies on AIGs demonstrated that one member of the gene family, AIG1, is involved in many biological processes in cancer cell lines and that ADTRP is associated with cardiovascular diseases. It has been shown that the numbers of AIG paralogs in humans, mice, and zebrafish are 2, 2, and 3, respectively, indicating possible gene duplication events during vertebrate evolution. Therefore, classifying subgroups of AIGs and identifying the homologs of each AIG member are important to characterize this novel gene family further. In this study, vertebrate AIGs were phylogenetically grouped into three major clades, ADTRP, AIG1, and AIG-L, with AIG-L also evident in an outgroup consisting of invertebrsate species. In this case, AIG-L, as the ancestral AIG, gave rise to ADTRP and AIG1 after two rounds of whole-genome duplications during vertebrate evolution. Then, the AIG family, which was exposed to purifying forces during evolution, lost or gained some of its members in some species. For example, in eutherians, Neognathae, and Percomorphaceae, AIG-L was lost; in contrast, Salmonidae and Cyprinidae acquired additional AIG copies. In conclusion, this study provides a comprehensive molecular phylogenetic analysis of vertebrate AIGs, which can be employed for future functional characterization of AIGs.


2019 ◽  
Author(s):  
Laura Hernández ◽  
Alberto Vicens ◽  
Luis Enrique Eguiarte ◽  
Valeria Souza ◽  
Valerie De Anda ◽  
...  

ABSTRACTDimethylsulfoniopropionate (DMSP), an osmolyte produced by oceanic phytoplankton, is predominantly degraded by bacteria belonging to the Roseobacter lineage and other marine Alphaproteobacteria via DMSP-dependent demethylase A protein (DmdA). To date, the evolutionary history of DmdA gene family is unclear. Some studies indicate a common ancestry between DmdA and GcvT gene families and a co-evolution between Roseobacter and the DMSP-producing-phytoplankton around 250 million years ago (Mya). In this work, we analyzed the evolution of DmdA under three possible evolutionary scenarios: 1) a recent common ancestor of DmdA and GcvT, 2) a coevolution between Roseobacter and the DMSP-producing-phytoplankton, and 3) pre-adapted enzymes to DMSP prior to Roseobacter origin. Our analyses indicate that DmdA is a new gene family originated from GcvT genes by duplication and functional divergence driven by positive selection before a coevolution between Roseobacter and phytoplankton. Our data suggest that Roseobacter acquired dmdA by horizontal gene transfer prior to exposition to an environment with higher DMSP. Here, we propose that the ancestor that carried the DMSP demethylation pathway genes evolved in the Archean, and was exposed to a higher concentration of DMSP in a sulfur rich atmosphere and anoxic ocean, compared to recent Roseobacter ecoparalogs (copies performing the same function under different conditions), which should be adapted to lower concentrations of DMSP.


2017 ◽  
Author(s):  
Daniel S. Carvalho ◽  
James C. Schnable ◽  
Ana Maria R. Almeida

AbstractThe study of gene family evolution has benefited from the use of phylogenetic tools, which can greatly inform studies of both relationships within gene families and functional divergence. Here, we propose the use of a network-based approach that in combination with phylogenetic methods can provide additional support for models of gene family evolution. We dissect the contributions of each method to the improved understanding of relationships and functions within the well-characterized family of AGAMOUS floral development genes. The results obtained with the two methods largely agreed with one another. In particular, we show how network approaches can provide improved interpretations of branches with low support in a conventional gene tree. The network approach used here may also better reflect known and suspected patterns of functional divergence relative to phylogenetic methods. Overall, we believe that the combined use of phylogenetic and network tools provide more robust assessments of gene family evolution.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9861
Author(s):  
Laura Hernández ◽  
Alberto Vicens ◽  
Luis E. Eguiarte ◽  
Valeria Souza ◽  
Valerie De Anda ◽  
...  

Dimethylsulfoniopropionate (DMSP), an osmolyte produced by oceanic phytoplankton and bacteria, is primarily degraded by bacteria belonging to the Roseobacter lineage and other marine Alphaproteobacteria via DMSP-dependent demethylase A protein (DmdA). To date, the evolutionary history of DmdA gene family is unclear. Some studies indicate a common ancestry between DmdA and GcvT gene families and a co-evolution between Roseobacter and the DMSP-producing-phytoplankton around 250 million years ago (Mya). In this work, we analyzed the evolution of DmdA under three possible evolutionary scenarios: (1) a recent common ancestor of DmdA and GcvT, (2) a coevolution between Roseobacter and the DMSP-producing-phytoplankton, and (3) an enzymatic adaptation for utilizing DMSP in marine bacteria prior to Roseobacter origin. Our analyses indicate that DmdA is a new gene family originated from GcvT genes by duplication and functional divergence driven by positive selection before a coevolution between Roseobacter and phytoplankton. Our data suggest that Roseobacter acquired dmdA by horizontal gene transfer prior to an environment with higher DMSP. Here, we propose that the ancestor that carried the DMSP demethylation pathway genes evolved in the Archean, and was exposed to a higher concentration of DMSP in a sulfur-rich atmosphere and anoxic ocean, compared to recent Roseobacter eco-orthologs (orthologs performing the same function under different conditions), which should be adapted to lower concentrations of DMSP.


Genetics ◽  
1993 ◽  
Vol 134 (4) ◽  
pp. 1271-1276
Author(s):  
T Ohta

Abstract The growth hormone-prolactin gene family in mammals is an interesting example of evolution by gene duplication. Divergence among members of duplicated gene families and among species was examined by using reported gene sequences of growth hormone, prolactin and their receptors. Sequence divergence among species was found to show a general tendency in which a generation-time effect is pronounced for synonymous substitutions but not so for nonsynonymous substitutions. Divergence among duplicated genes is characterized by the relatively high rate of nonsynonymous substitutions, i.e., the rate is close to that of synonymous ones. In view of the stage- and tissue-specific expression of duplicated genes, some of the amino acid substitutions among duplicated genes is likely to be caused by positive Darwinian selection.


2019 ◽  
Vol 20 (7) ◽  
pp. 1750 ◽  
Author(s):  
Ghulam Qanmber ◽  
Ji Liu ◽  
Daoqian Yu ◽  
Zhao Liu ◽  
Lili Lu ◽  
...  

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.


2021 ◽  
Author(s):  
Arthur Zwaenepoel ◽  
Yves Van de Peer

AbstractPhylogenetic models of gene family evolution based on birth-death processes (BDPs) vide an awkward fit to comparative genomic data sets. A central assumption of these models is the constant per-gene loss rate in any particular family. Because of the possibility of partial functional redundancy among gene family members, gene loss dynamics are however likely to be dependent on the number of genes in a family, and different variations of commonly employed BDP models indeed suggest this is the case. We propose a simple two-type branching process model to better approximate the stochastic evolution of gene families by gene duplication and loss and perform Bayesian statistical inference of model parameters in a phylogenetic context. We evaluate the statistical methods using simulated data sets and apply the model to gene family data for Drosophila, yeasts and primates, providing new quantitative insights in the long-term maintenance of duplicated genes.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4379 ◽  
Author(s):  
Dan Wang ◽  
Jietang Zhao ◽  
Bing Hu ◽  
Jiaqi Li ◽  
Yaqi Qin ◽  
...  

Sucrose phosphate synthase (SPS, EC 2.4.1.14) is a key enzyme that regulates sucrose biosynthesis in plants. SPS is encoded by different gene families which display differential expression patterns and functional divergence. Genome-wide identification and expression analyses of SPS gene families have been performed in Arabidopsis, rice, and sugarcane, but a comprehensive analysis of the SPS gene family in Litchi chinensis Sonn. has not yet been reported. In the current study, four SPS gene (LcSPS1, LcSPS2, LcSPS3, and LcSPS4) were isolated from litchi. The genomic organization analysis indicated the four litchi SPS genes have very similar exon-intron structures. Phylogenetic tree showed LcSPS1-4 were grouped into different SPS families (LcSPS1 and LcSPS2 in A family, LcSPS3 in B family, and LcSPS4 in C family). LcSPS1 and LcSPS4 were strongly expressed in the flowers, while LcSPS3 most expressed in mature leaves. RT-qPCR results showed that LcSPS genes expressed differentially during aril development between cultivars with different hexose/sucrose ratios. A higher level of expression of LcSPS genes was detected in Wuheli, which accumulates higher sucrose in the aril at mature. The tissue- and developmental stage-specific expression of LcSPS1-4 genes uncovered in this study increase our understanding of the important roles played by these genes in litchi fruits.


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