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Dynamic Patterns of Sex Chromosome Evolution in Neognath Birds: Many Independent Barriers to Recombination at the ATP5F1A Locus. BIRDS 2022. [DOI: 10.3390/birds3010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Avian sex chromosomes evolved after the divergence of birds and crocodilians from their common ancestor, so they are younger than the better-studied chromosomes of mammals. It has long been recognized that there may have been several stages to the evolution of avian sex chromosomes. For example, the CHD1 undergoes recombination in paleognaths but not neognaths. Genome assemblies have suggested that there may be variation in the timing of barriers to recombination among Neognathae, but there remains little understanding of the extent of this variability. Here, we look at partial sequences of ATP5F1A, which is on the avian Z and W chromosomes. It is known that recombination of this gene has independently ceased in Galliformes, Anseriformes, and at least five neoavian orders, but whether there are other independent cessations of recombination among Neoaves is not understood. We analyzed a combination of data extracted from published chromosomal-level genomes with data collected using PCR and cloning to identify Z and W copies in 22 orders. Our results suggest that there may be at least 19 independent cessations of recombination within Neognathae, and 3 clades that may still be undergoing recombination (or have only recently ceased recombination). Analyses of ATP5F1A protein sequences revealed an increased amino acid substitution rate for W chromosome gametologs, suggesting relaxed purifying selection on the W chromosome. Supporting this hypothesis, we found that the increased substitution rate was particularly pronounced for buried residues, which are expected to be more strongly constrained by purifying selection. This highlights the dynamic nature of avian sex chromosomes, and that this level of variation among clades means they should be a good system to understand sex chromosome evolution.
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2
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Fernandez-Fuertes B, Sánchez JM, Bagés-Arnal S, McDonald M, Yeste M, Lonergan P. Species-specific and collection method-dependent differences in endometrial susceptibility to seminal plasma-induced RNA degradation. Sci Rep 2019; 9:15072. [PMID: 31636362 PMCID: PMC6803643 DOI: 10.1038/s41598-019-51413-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/01/2019] [Indexed: 12/18/2022] Open
Abstract
This study aimed to determine the effect of bull seminal plasma (SP) and sperm on endometrial function. Bovine endometrial explants were incubated with: ejaculated sperm with or without SP, epididymal sperm, or SP alone. Neither ejaculated nor epididymal sperm induced differential expression of IL1A, IL1B, IL6, IL8, PTGES2, TNFA, and LIF. Interestingly, SP had a detrimental effect on endometrial RNA integrity. Addition of an RNase inactivation reagent to SP blocked this effect, evidencing a role for a SP-RNase. Because bulls deposit the ejaculate in the vagina, we hypothesized that the bovine endometrium is more sensitive to SP-RNase than vaginal and cervical tissues (which come into contact with SP during mating), or to endometrium from intrauterine ejaculators (such as the horse). In addition, due to differences in SP-RNase abundance depending on SP collection method (i.e., with an artificial vagina, AV, or by electroejaculation, EE), this effect was also tested. Bull SP, collected by AV, degrades RNA of mare endometrium, and bovine vagina, cervix and endometrium. However, stallion SP or bull SP collected by EE did not elicit this effect. Thus, results do not support a role for SP in modulating endometrial function to establish pregnancy in cattle.
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Affiliation(s)
- Beatriz Fernandez-Fuertes
- Department of Biology, Faculty of Sciences, Institute of Food and Agricultural Technology, University of Girona, Girona, Spain.
| | - José María Sánchez
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland
| | - Sandra Bagés-Arnal
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland
| | - Michael McDonald
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland
| | - Marc Yeste
- Department of Biology, Faculty of Sciences, Institute of Food and Agricultural Technology, University of Girona, Girona, Spain
| | - Pat Lonergan
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland
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3
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Exploring the past and the future of protein evolution with ancestral sequence reconstruction: the 'retro' approach to protein engineering. Biochem J 2017; 474:1-19. [PMID: 28008088 DOI: 10.1042/bcj20160507] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 12/22/2022]
Abstract
A central goal in molecular evolution is to understand the ways in which genes and proteins evolve in response to changing environments. In the absence of intact DNA from fossils, ancestral sequence reconstruction (ASR) can be used to infer the evolutionary precursors of extant proteins. To date, ancestral proteins belonging to eubacteria, archaea, yeast and vertebrates have been inferred that have been hypothesized to date from between several million to over 3 billion years ago. ASR has yielded insights into the early history of life on Earth and the evolution of proteins and macromolecular complexes. Recently, however, ASR has developed from a tool for testing hypotheses about protein evolution to a useful means for designing novel proteins. The strength of this approach lies in the ability to infer ancestral sequences encoding proteins that have desirable properties compared with contemporary forms, particularly thermostability and broad substrate range, making them good starting points for laboratory evolution. Developments in technologies for DNA sequencing and synthesis and computational phylogenetic analysis have led to an escalation in the number of ancient proteins resurrected in the last decade and greatly facilitated the use of ASR in the burgeoning field of synthetic biology. However, the primary challenge of ASR remains in accurately inferring ancestral states, despite the uncertainty arising from evolutionary models, incomplete sequences and limited phylogenetic trees. This review will focus, firstly, on the use of ASR to uncover links between sequence and phenotype and, secondly, on the practical application of ASR in protein engineering.
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Yohe LR, Abubakar R, Giordano C, Dumont E, Sears KE, Rossiter SJ, Dávalos LM. Trpc2 pseudogenization dynamics in bats reveal ancestral vomeronasal signaling, then pervasive loss. Evolution 2017; 71:923-935. [PMID: 28128447 DOI: 10.1111/evo.13187] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 12/30/2016] [Indexed: 01/08/2023]
Abstract
Comparative methods are often used to infer loss or gain of complex phenotypes, but few studies take advantage of genes tightly linked with complex traits to test for shifts in the strength of selection. In mammals, vomerolfaction detects chemical cues mediating many social and reproductive behaviors and is highly conserved, but all bats exhibit degraded vomeronasal structures with the exception of two families (Phyllostomidae and Miniopteridae). These families either regained vomerolfaction after ancestral loss, or there were many independent losses after diversification from an ancestor with functional vomerolfaction. In this study, we use the Transient receptor potential cation channel 2 (Trpc2) as a molecular marker for testing the evolutionary mechanisms of loss and gain of the mammalian vomeronasal system. We sequenced Trpc2 exon 2 in over 100 bat species across 17 of 20 chiropteran families. Most families showed independent pseudogenizing mutations in Trpc2, but the reading frame was highly conserved in phyllostomids and miniopterids. Phylogeny-based simulations suggest loss of function occurred after bat families diverged, and purifying selection in two families has persisted since bats shared a common ancestor. As most bats still display pheromone-mediated behavior, they might detect pheromones through the main olfactory system without using the Trpc2 signaling mechanism.
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Affiliation(s)
- Laurel R Yohe
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794
| | - Ramatu Abubakar
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794
| | - Christina Giordano
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794
| | - Elizabeth Dumont
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, 01003
| | - Karen E Sears
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, 61801.,School of Integrative Biology, Institute for Genome Biology, University of Illinois, Urbana, Illinois, 61801
| | - Stephen J Rossiter
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom
| | - Liliana M Dávalos
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794.,Consortium for Inter-Disciplinary Environmental Research, Stony Brook University, Stony Brook, New York, 11794
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Todesco M, Kim ST, Chae E, Bomblies K, Zaidem M, Smith LM, Weigel D, Laitinen RAE. Activation of the Arabidopsis thaliana immune system by combinations of common ACD6 alleles. PLoS Genet 2014; 10:e1004459. [PMID: 25010663 PMCID: PMC4091793 DOI: 10.1371/journal.pgen.1004459] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 05/09/2014] [Indexed: 11/23/2022] Open
Abstract
A fundamental question in biology is how multicellular organisms distinguish self and non-self. The ability to make this distinction allows animals and plants to detect and respond to pathogens without triggering immune reactions directed against their own cells. In plants, inappropriate self-recognition results in the autonomous activation of the immune system, causing affected individuals to grow less well. These plants also suffer from spontaneous cell death, but are at the same time more resistant to pathogens. Known causes for such autonomous activation of the immune system are hyperactive alleles of immune regulators, or epistatic interactions between immune regulators and unlinked genes. We have discovered a third class, in which the Arabidopsis thaliana immune system is activated by interactions between natural alleles at a single locus, ACCELERATED CELL DEATH 6 (ACD6). There are two main types of these interacting alleles, one of which has evolved recently by partial resurrection of a pseudogene, and each type includes multiple functional variants. Most previously studies hybrid necrosis cases involve rare alleles found in geographically unrelated populations. These two types of ACD6 alleles instead occur at low frequency throughout the range of the species, and have risen to high frequency in the Northeast of Spain, suggesting a role in local adaptation. In addition, such hybrids occur in these populations in the wild. The extensive functional variation among ACD6 alleles points to a central role of this locus in fine-tuning pathogen defenses in natural populations. Plants and their pathogens are engaged in an endless evolutionary battle. The invention of new strategies by pathogens pushes plants to continuously update their defenses. This in turn leads the pathogens to circumvent these new defenses, and so on. Given the abundance of potential enemies, it is therefore not surprising that genes involved in defense against pathogens are among the most variable in plants. A drawback of this extreme variation in pathogen-recognition mechanisms is that at times the plant mistakes itself for an enemy, leading to autonomous activation of defense responses in the absence of pathogens. Conventional models for this phenomenon, called hybrid necrosis, require the interaction between two different genes. Here we show instead that hybrid necrosis can be triggered by interactions between variants of a single gene, ACD6 (ACCELERATED CELL DEATH 6). Several of these variants are common in natural Arabidopsis thaliana populations and can interact to give different levels of activation of the immune system. Our results provide important information into the evolution and operation of the plant defense system. Moreover, the abundant presence of ACD6 functional variation suggests a major role for this gene in modulating plant defenses in nature.
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Affiliation(s)
- Marco Todesco
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Sang-Tae Kim
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Eunyoung Chae
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Kirsten Bomblies
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Maricris Zaidem
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Lisa M. Smith
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
- * E-mail:
| | - Roosa A. E. Laitinen
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
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Evolutionary and functional novelty of pancreatic ribonuclease: a study of Musteloidea (order Carnivora). Sci Rep 2014; 4:5070. [PMID: 24861105 PMCID: PMC5381406 DOI: 10.1038/srep05070] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 04/30/2014] [Indexed: 11/08/2022] Open
Abstract
Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in studies of evolutionary innovation and functional diversification. It has been believed that the RNASE1 gene duplications are correlated with the plant-feeding adaptation of foregut-fermenting herbivores. Here, we characterized RNASE1 genes from Caniformia, which has a simple digestive system and lacks microbial digestion typical of herbivores, in an unprecedented scope based on both gene sequence and tissue expression analyses. Remarkably, the results yielded new hypotheses regarding the evolution and the function of Caniformia RNASE1 genes. Four independent gene duplication events in the families of superfamily Musteloidea, including Procyonidae, Ailuridae, Mephitidae and Mustelidae, were recovered, rejecting previous Mustelidae-specific duplication hypothesis, but supporting Musteloidea duplication hypothesis. Moreover, our analyses revealed pronounced differences among the RNASE1 gene copies regarding their selection pressures, pI values and tissue expression patterns, suggesting the differences in their physiological functions. Notably, the expression analyses detected the transcription of a RNASE1 pseudogene in several tissues, raising the possibility that pseudogenes are also a potential source during the RNase functional diversification. In sum, the present work demonstrated a far more complex and intriguing evolutionary pattern and functional diversity of mammalian ribonuclease than previously thought.
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Graur D, Zheng Y, Price N, Azevedo RBR, Zufall RA, Elhaik E. On the immortality of television sets: "function" in the human genome according to the evolution-free gospel of ENCODE. Genome Biol Evol 2013; 5:578-90. [PMID: 23431001 PMCID: PMC3622293 DOI: 10.1093/gbe/evt028] [Citation(s) in RCA: 302] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2013] [Indexed: 12/11/2022] Open
Abstract
A recent slew of ENCyclopedia Of DNA Elements (ENCODE) Consortium publications, specifically the article signed by all Consortium members, put forward the idea that more than 80% of the human genome is functional. This claim flies in the face of current estimates according to which the fraction of the genome that is evolutionarily conserved through purifying selection is less than 10%. Thus, according to the ENCODE Consortium, a biological function can be maintained indefinitely without selection, which implies that at least 80 - 10 = 70% of the genome is perfectly invulnerable to deleterious mutations, either because no mutation can ever occur in these "functional" regions or because no mutation in these regions can ever be deleterious. This absurd conclusion was reached through various means, chiefly by employing the seldom used "causal role" definition of biological function and then applying it inconsistently to different biochemical properties, by committing a logical fallacy known as "affirming the consequent," by failing to appreciate the crucial difference between "junk DNA" and "garbage DNA," by using analytical methods that yield biased errors and inflate estimates of functionality, by favoring statistical sensitivity over specificity, and by emphasizing statistical significance rather than the magnitude of the effect. Here, we detail the many logical and methodological transgressions involved in assigning functionality to almost every nucleotide in the human genome. The ENCODE results were predicted by one of its authors to necessitate the rewriting of textbooks. We agree, many textbooks dealing with marketing, mass-media hype, and public relations may well have to be rewritten.
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Affiliation(s)
- Dan Graur
- Department of Biology and Biochemistry, University of Houston, TX, USA.
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Carrigan MA, Uryasev O, Davis RP, Zhai L, Hurley TD, Benner SA. The natural history of class I primate alcohol dehydrogenases includes gene duplication, gene loss, and gene conversion. PLoS One 2012; 7:e41175. [PMID: 22859968 PMCID: PMC3409193 DOI: 10.1371/journal.pone.0041175] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 06/18/2012] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Gene duplication is a source of molecular innovation throughout evolution. However, even with massive amounts of genome sequence data, correlating gene duplication with speciation and other events in natural history can be difficult. This is especially true in its most interesting cases, where rapid and multiple duplications are likely to reflect adaptation to rapidly changing environments and life styles. This may be so for Class I of alcohol dehydrogenases (ADH1s), where multiple duplications occurred in primate lineages in Old and New World monkeys (OWMs and NWMs) and hominoids. METHODOLOGY/PRINCIPAL FINDINGS To build a preferred model for the natural history of ADH1s, we determined the sequences of nine new ADH1 genes, finding for the first time multiple paralogs in various prosimians (lemurs, strepsirhines). Database mining then identified novel ADH1 paralogs in both macaque (an OWM) and marmoset (a NWM). These were used with the previously identified human paralogs to resolve controversies relating to dates of duplication and gene conversion in the ADH1 family. Central to these controversies are differences in the topologies of trees generated from exonic (coding) sequences and intronic sequences. CONCLUSIONS/SIGNIFICANCE We provide evidence that gene conversions are the primary source of difference, using molecular clock dating of duplications and analyses of microinsertions and deletions (micro-indels). The tree topology inferred from intron sequences appear to more correctly represent the natural history of ADH1s, with the ADH1 paralogs in platyrrhines (NWMs) and catarrhines (OWMs and hominoids) having arisen by duplications shortly predating the divergence of OWMs and NWMs. We also conclude that paralogs in lemurs arose independently. Finally, we identify errors in database interpretation as the source of controversies concerning gene conversion. These analyses provide a model for the natural history of ADH1s that posits four ADH1 paralogs in the ancestor of Catarrhine and Platyrrhine primates, followed by the loss of an ADH1 paralog in the human lineage.
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Affiliation(s)
- Matthew A Carrigan
- Foundation for Applied Molecular Evolution, Gainesville, Florida, United States of America.
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9
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Lim CH, Hamazaki T, Braun EL, Wade J, Terada N. Evolutionary genomics implies a specific function of Ant4 in mammalian and anole lizard male germ cells. PLoS One 2011; 6:e23122. [PMID: 21858006 PMCID: PMC3155547 DOI: 10.1371/journal.pone.0023122] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 07/11/2011] [Indexed: 11/18/2022] Open
Abstract
Most vertebrates have three paralogous genes with identical intron-exon structures and a high degree of sequence identity that encode mitochondrial adenine nucleotide translocase (Ant) proteins, Ant1 (Slc25a4), Ant2 (Slc25a5) and Ant3 (Slc25a6). Recently, we and others identified a fourth mammalian Ant paralog, Ant4 (Slc25a31), with a distinct intron-exon structure and a lower degree of sequence identity. Ant4 was expressed selectively in testis and sperm in adult mammals and was indeed essential for mouse spermatogenesis, but it was absent in birds, fish and frogs. Since Ant2 is X-linked in mammalian genomes, we hypothesized that the autosomal Ant4 gene may compensate for the loss of Ant2 gene expression during male meiosis in mammals. Here we report that the Ant4 ortholog is conserved in green anole lizard (Anolis carolinensis) and demonstrate that it is expressed in the anole testis. Further, a degenerate DNA fragment of putative Ant4 gene was identified in syntenic regions of avian genomes, indicating that Ant4 was present in the common amniote ancestor. Phylogenetic analyses suggest an even more ancient origin of the Ant4 gene. Although anole lizards are presumed male (XY) heterogametic, like mammals, copy numbers of the Ant2 as well as its neighboring gene were similar between male and female anole genomes, indicating that the anole Ant2 gene is either autosomal or located in the pseudoautosomal region of the sex chromosomes, in contrast to the case to mammals. These results imply the conservation of Ant4 is not likely simply driven by the sex chromosomal localization of the Ant2 gene and its subsequent inactivation during male meiosis. Taken together with the fact that Ant4 protein has a uniquely conserved structure when compared to other somatic Ant1, 2 and 3, there may be a specific advantage for mammals and lizards to express Ant4 in their male germ cells.
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Affiliation(s)
- Chae Ho Lim
- Department of Pathology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Takashi Hamazaki
- Department of Pathology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Edward L. Braun
- Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Juli Wade
- Neuroscience Program, Department of Psychology, Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America
| | - Naohiro Terada
- Department of Pathology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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McCole RB, Loughran NB, Chahal M, Fernandes LP, Roberts RG, Fraternali F, O'Connell MJ, Oakey RJ. A case-by-case evolutionary analysis of four imprinted retrogenes. Evolution 2011; 65:1413-27. [PMID: 21166792 PMCID: PMC3107425 DOI: 10.1111/j.1558-5646.2010.01213.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Accepted: 11/30/2010] [Indexed: 11/29/2022]
Abstract
Retroposition is a widespread phenomenon resulting in the generation of new genes that are initially related to a parent gene via very high coding sequence similarity. We examine the evolutionary fate of four retrogenes generated by such an event; mouse Inpp5f_v2, Mcts2, Nap1l5, and U2af1-rs1. These genes are all subject to the epigenetic phenomenon of parental imprinting. We first provide new data on the age of these retrogene insertions. Using codon-based models of sequence evolution, we show these retrogenes have diverse evolutionary trajectories, including divergence from the parent coding sequence under positive selection pressure, purifying selection pressure maintaining parent-retrogene similarity, and neutral evolution. Examination of the expression pattern of retrogenes shows an atypical, broad pattern across multiple tissues. Protein 3D structure modeling reveals that a positively selected residue in U2af1-rs1, not shared by its parent, may influence protein conformation. Our case-by-case analysis of the evolution of four imprinted retrogenes reveals that this interesting class of imprinted genes, while similar in regulation and sequence characteristics, follow very varied evolutionary paths.
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Affiliation(s)
- Ruth B McCole
- Department of Medical and Molecular Genetics, King's College LondonLondon SE1 9RT, United Kingdom
- E-mail:
| | - Noeleen B Loughran
- Bioinformatics and Molecular Evolution Group, School of Biotechnology, Faculty of Science and Health, Dublin City UniversityGlasnevin Dublin 9, Ireland
- Centre for Scientific Computing & Complex Systems modeling (SCI-SYM), Dublin City UniversityGlasnevin Dublin 9, Ireland
- E-mail:
| | - Mandeep Chahal
- Department of Medical and Molecular Genetics, King's College LondonLondon SE1 9RT, United Kingdom
- E-mail:
| | - Luis P Fernandes
- Randall Division of Cell and Molecular Biophysics, King's College LondonLondon SE1 1UL, United Kingdom
- E-mail:
| | - Roland G Roberts
- Department of Medical and Molecular Genetics, King's College LondonLondon SE1 9RT, United Kingdom
- E-mail:
| | - Franca Fraternali
- Randall Division of Cell and Molecular Biophysics, King's College LondonLondon SE1 1UL, United Kingdom
- E-mail:
| | - Mary J O'Connell
- Bioinformatics and Molecular Evolution Group, School of Biotechnology, Faculty of Science and Health, Dublin City UniversityGlasnevin Dublin 9, Ireland
- Centre for Scientific Computing & Complex Systems modeling (SCI-SYM), Dublin City UniversityGlasnevin Dublin 9, Ireland
- E-mail:
| | - Rebecca J Oakey
- Department of Medical and Molecular Genetics, King's College LondonLondon SE1 9RT, United Kingdom
- E-mail:
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11
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Zhu J, Braun EL, Kohno S, Antenos M, Xu EY, Cook RW, Lin SJ, Moore BC, Guillette LJ, Jardetzky TS, Woodruff TK. Phylogenomic analyses reveal the evolutionary origin of the inhibin alpha-subunit, a unique TGFbeta superfamily antagonist. PLoS One 2010; 5:e9457. [PMID: 20209104 PMCID: PMC2832003 DOI: 10.1371/journal.pone.0009457] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 02/01/2010] [Indexed: 11/18/2022] Open
Abstract
Transforming growth factor-beta (TGFβ) homologues form a diverse superfamily that arose early in animal evolution and control cellular function through membrane-spanning, conserved serine-threonine kinases (RII and RI receptors). Activin and inhibin are related dimers within the TGFβ superfamily that share a common β-subunit. The evolution of the inhibin α-subunit created the only antagonist within the TGFβ superfamily and the only member known to act as an endocrine hormone. This hormone introduced a new level of complexity and control to vertebrate reproductive function. The novel functions of the inhibin α-subunit appear to reflect specific insertion-deletion changes within the inhibin β-subunit that occurred during evolution. Using phylogenomic analysis, we correlated specific insertions with the acquisition of distinct functions that underlie the phenotypic complexity of vertebrate reproductive processes. This phylogenomic approach presents a new way of understanding the structure-function relationships between inhibin, activin, and the larger TGFβ superfamily.
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Affiliation(s)
- Jie Zhu
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Edward L. Braun
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
| | - Satomi Kohno
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
| | - Monica Antenos
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Eugene Y. Xu
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Robert W. Cook
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - S. Jack Lin
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Brandon C. Moore
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
| | - Louis J. Guillette
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
| | - Theodore S. Jardetzky
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Teresa K. Woodruff
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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12
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Weadick CJ, Chang BSW. Molecular evolution of the betagamma lens crystallin superfamily: evidence for a retained ancestral function in gamma N crystallins? Mol Biol Evol 2009; 26:1127-42. [PMID: 19233964 DOI: 10.1093/molbev/msp028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Within the vertebrate eye, betagamma crystallins are extremely stable lens proteins that are uniquely adapted to increase refractory power while maintaining transparency. Unlike alpha crystallins, which are well-characterized, multifunctional proteins that have important functions both in and out of the lens, betagamma lens crystallins are a diverse group of proteins with no clear ancestral or contemporary nonlens role. We carried out phylogenetic and molecular evolutionary analyses of the betagamma-crystallin superfamily in order to study the evolutionary history of the gamma N crystallins, a recently discovered, biochemically atypical family suggested to possess a divergent or ancestral function. By including nonlens, betagamma-motif-containing sequences in our analysis as outgroups, we confirmed the phylogenetic position of the gamma N family as sister to other gamma crystallins. Using maximum likelihood codon models to estimate lineage-specific nonsynonymous-to-synonymous rate ratios revealed strong positive selection in all of the early lineages within the betagamma family, with the striking exception of the lineage leading to the gamma N crystallins which was characterized by strong purifying selection. Branch-site analysis, used to identify candidate sites involved in functional divergence between gamma N crystallins and its sister clade containing all other gamma crystallins, identified several positively selected changes at sites of known functional importance in the betagamma crystallin protein structure. Further analyses of a fish-specific gamma N crystallin gene duplication revealed a more recent episode of positive selection in only one of the two descendant lineages (gamma N2). Finally, from the guppy, Poecilia reticulata, we isolated complete gamma N1 and gamma N2 coding sequence data from cDNA and partial coding sequence data from genomic DNA in order to confirm the presence of a novel gamma N2 intron, discovered through data mining of two pufferfish genomes. We conclude that the function of the gamma N family likely resembles the ancestral vertebrate betagamma crystallin more than other betagamma families. Furthermore, owing to the presence of an additional intron in some fish gamma N2 crystallins, and the inferred action of positive selection following the fish-specific gamma N duplication, we suggest that further study of fish gamma N crystallins will be critical in further elucidating possible ancestral functions of gamma N crystallins and any nonstructural role they may have.
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Affiliation(s)
- Cameron J Weadick
- Department of Ecology and Evolution, University of Toronto, Toronto, Ontario, Canada
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Lam HYK, Khurana E, Fang G, Cayting P, Carriero N, Cheung KH, Gerstein MB. Pseudofam: the pseudogene families database. Nucleic Acids Res 2008; 37:D738-43. [PMID: 18957444 PMCID: PMC2686518 DOI: 10.1093/nar/gkn758] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pseudofam (http://pseudofam.pseudogene.org) is a database of pseudogene families based on the protein families from the Pfam database. It provides resources for analyzing the family structure of pseudogenes including query tools, statistical summaries and sequence alignments. The current version of Pseudofam contains more than 125,000 pseudogenes identified from 10 eukaryotic genomes and aligned within nearly 3000 families (approximately one-third of the total families in PfamA). Pseudofam uses a large-scale parallelized homology search algorithm (implemented as an extension of the PseudoPipe pipeline) to identify pseudogenes. Each identified pseudogene is assigned to its parent protein family and subsequently aligned to each other by transferring the parent domain alignments from the Pfam family. Pseudogenes are also given additional annotation based on an ontology, reflecting their mode of creation and subsequent history. In particular, our annotation highlights the association of pseudogene families with genomic features, such as segmental duplications. In addition, pseudogene families are associated with key statistics, which identify outlier families with an unusual degree of pseudogenization. The statistics also show how the number of genes and pseudogenes in families correlates across different species. Overall, they highlight the fact that housekeeping families tend to be enriched with a large number of pseudogenes.
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Affiliation(s)
- Hugo Y K Lam
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA
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Georgelis N, Braun EL, Hannah LC. Duplications and functional divergence of ADP-glucose pyrophosphorylase genes in plants. BMC Evol Biol 2008; 8:232. [PMID: 18700010 PMCID: PMC2529307 DOI: 10.1186/1471-2148-8-232] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Accepted: 08/12/2008] [Indexed: 11/23/2022] Open
Abstract
Background ADP-glucose pyrophosphorylase (AGPase), which catalyses a rate limiting step in starch synthesis, is a heterotetramer comprised of two identical large and two identical small subunits in plants. Although the large and small subunits are equally sensitive to activity-altering amino acid changes when expressed in a bacterial system, the overall rate of non-synonymous evolution is ~2.7-fold greater for the large subunit than for the small subunit. Herein, we examine the basis for their different rates of evolution, the number of duplications in both large and small subunit genes and document changes in the patterns of AGPase evolution over time. Results We found that the first duplication in the AGPase large subunit family occurred early in the history of land plants, while the earliest small subunit duplication occurred after the divergence of monocots and eudicots. The large subunit also had a larger number of gene duplications than did the small subunit. The ancient duplications in the large subunit family raise concern about the saturation of synonymous substitutions, but estimates of the absolute rate of AGPase evolution were highly correlated with estimates of ω (the non-synonymous to synonymous rate ratio). Both subunits showed evidence for positive selection and relaxation of purifying selection after duplication, but these phenomena could not explain the different evolutionary rates of the two subunits. Instead, evolutionary constraints appear to be permanently relaxed for the large subunit relative to the small subunit. Both subunits exhibit branch-specific patterns of rate variation among sites. Conclusion These analyses indicate that the higher evolutionary rate of the plant AGPase large subunit reflects permanent relaxation of constraints relative to the small subunit and they show that the large subunit genes have undergone more gene duplications than small subunit genes. Candidate sites potentially responsible for functional divergence within each of the AGPase subunits were investigated by examining branch-specific patterns of rate variation. We discuss the phenotypes of mutants that alter some candidate sites and strategies for examining candidate sites of presently unknown function.
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Affiliation(s)
- Nikolaos Georgelis
- Program in Plant Molecular and Cellular Biology and Horticultural Sciences, University of Florida, Gainesville, Florida 32610-0245, USA.
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Yuri T, Kimball RT, Braun EL, Braun MJ. Duplication of Accelerated Evolution and Growth Hormone Gene in Passerine Birds. Mol Biol Evol 2007; 25:352-61. [DOI: 10.1093/molbev/msm260] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Johnson RJ, Lin SR, Raines RT. Genetic selection reveals the role of a buried, conserved polar residue. Protein Sci 2007; 16:1609-16. [PMID: 17656580 PMCID: PMC2203362 DOI: 10.1110/ps.072938907] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 05/14/2007] [Accepted: 05/15/2007] [Indexed: 12/24/2022]
Abstract
The burial of nonpolar surface area is known to enhance markedly the conformational stability of proteins. The contribution from the burial of polar surface area is less clear. Here, we report on the tolerance to substitution of Ser75 of bovine pancreatic ribonuclease (RNase A), a residue that has the unusual attributes of being buried, conserved, and polar. To identify variants that retain biological function, we used a genetic selection based on the intrinsic cytotoxicity of ribonucleolytic activity. Cell growth at 30 degrees C, 37 degrees C, and 44 degrees C correlated with residue size, indicating that the primary attribute of Ser75 is its small size. The side-chain hydroxyl group of Ser75 forms a hydrogen bond with a main-chain nitrogen. The conformational stability of the S75A variant, which lacks this hydrogen bond, was diminished by DeltaDeltaG = 2.5 kcal/mol. Threonine, which can reinstate this hydrogen bond, provided a catalytically active RNase A variant at higher temperatures than did some smaller residues (including aspartate), indicating that a secondary attribute of Ser75 is the ability of its uncharged side chain to accept a hydrogen bond. These results provide insight on the imperatives for the conservation of a buried polar residue.
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Affiliation(s)
- R Jeremy Johnson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1544, USA
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