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Liu G, Pan Q, Dai Y, Wang X, Li M, Zhu P, Zhou X. Phylogenomics of Afrotherian mammals and improved resolution of extant Paenungulata. Mol Phylogenet Evol 2024; 195:108047. [PMID: 38460890 DOI: 10.1016/j.ympev.2024.108047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/19/2024] [Accepted: 03/06/2024] [Indexed: 03/11/2024]
Abstract
Molecular investigations have gathered a diverse set of mammals-predominantly African natives like elephants, hyraxes, and aardvarks-into a clade known as Afrotheria. Nevertheless, the precise phylogenetic relationships among these species remain contentious. Here, we sourced orthologous markers and ultraconserved elements to discern the interordinal connections among Afrotherian mammals. Our phylogenetic analyses bolster the common origin of Afroinsectiphilia and Paenungulata, and propose Afrosoricida as the closer relative to Macroscelidea rather than Tubulidentata, while also challenging the notion of Sirenia and Hyracoidea as sister taxa. The approximately unbiased test and the gene concordance factor uniformly recognized the alliance of Proboscidea with Hyracoidea as the dominant topology within Paenungulata. Investigation into sites with extremly high phylogenetic signal unveiled their potential to intensify conflicts in the Paenungulata topology. Subsequent exploration suggested that incomplete lineage sorting was predominantly responsible for the observed contentious relationships, whereas introgression exerted a subsidiary influence. The divergence times estimated in our study hint at the Cretaceous-Paleogene (K-Pg) extinction event as a catalyst for Afrotherian diversification. Overall, our findings deliver a tentative but insightful overview of Afrotheria phylogeny and divergence, elucidating these relationships through the lens of phylogenomics.
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Affiliation(s)
- Gaoming Liu
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qi Pan
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yichen Dai
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiao Wang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Meng Li
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Pingfen Zhu
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xuming Zhou
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
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Steenwyk JL, Goltz DC, Buida TJ, Li Y, Shen XX, Rokas A. OrthoSNAP: A tree splitting and pruning algorithm for retrieving single-copy orthologs from gene family trees. PLoS Biol 2022; 20:e3001827. [PMID: 36228036 PMCID: PMC9595520 DOI: 10.1371/journal.pbio.3001827] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 10/25/2022] [Accepted: 09/13/2022] [Indexed: 11/19/2022] Open
Abstract
Molecular evolution studies, such as phylogenomic studies and genome-wide surveys of selection, often rely on gene families of single-copy orthologs (SC-OGs). Large gene families with multiple homologs in 1 or more species-a phenomenon observed among several important families of genes such as transporters and transcription factors-are often ignored because identifying and retrieving SC-OGs nested within them is challenging. To address this issue and increase the number of markers used in molecular evolution studies, we developed OrthoSNAP, a software that uses a phylogenetic framework to simultaneously split gene families into SC-OGs and prune species-specific inparalogs. We term SC-OGs identified by OrthoSNAP as SNAP-OGs because they are identified using a splitting and pruning procedure analogous to snapping branches on a tree. From 415,129 orthologous groups of genes inferred across 7 eukaryotic phylogenomic datasets, we identified 9,821 SC-OGs; using OrthoSNAP on the remaining 405,308 orthologous groups of genes, we identified an additional 10,704 SNAP-OGs. Comparison of SNAP-OGs and SC-OGs revealed that their phylogenetic information content was similar, even in complex datasets that contain a whole-genome duplication, complex patterns of duplication and loss, transcriptome data where each gene typically has multiple transcripts, and contentious branches in the tree of life. OrthoSNAP is useful for increasing the number of markers used in molecular evolution data matrices, a critical step for robustly inferring and exploring the tree of life.
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Affiliation(s)
- Jacob L. Steenwyk
- Vanderbilt University, Department of Biological Sciences, Nashville, Tennessee, United States of America
- Vanderbilt Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail: (JLS); (AR)
| | - Dayna C. Goltz
- Independent Researcher, Nashville, Tennessee, United States of America
| | - Thomas J. Buida
- Independent Researcher, Nashville, Tennessee, United States of America
| | - Yuanning Li
- Vanderbilt University, Department of Biological Sciences, Nashville, Tennessee, United States of America
- Vanderbilt Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, United States of America
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Xing-Xing Shen
- Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Antonis Rokas
- Vanderbilt University, Department of Biological Sciences, Nashville, Tennessee, United States of America
- Vanderbilt Evolutionary Studies Initiative, Vanderbilt University, Nashville, Tennessee, United States of America
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
- * E-mail: (JLS); (AR)
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Paszta W, Klećkowska-Nawrot JE, Goździewska-Harłajczuk K. Morphological evaluation of the orbit, eye tunics, eyelids, and orbital glands in young and adult aardvarks Orycteropus afer, Pallas, 1766 (Tubulidentata: Orycteropodidae) - similarities and differences with representatives of the Afrotheria clade. Anat Rec (Hoboken) 2022; 305:3317-3340. [PMID: 35202514 DOI: 10.1002/ar.24905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/27/2021] [Accepted: 01/04/2022] [Indexed: 11/12/2022]
Abstract
The Afrotheria clade includes a large group of extant mammals, and the aardvark (Orycteropus afer) is the only representative of the order Tubulidentata in it. Here, we studied the morphological nature of the orbital region, eye tunics, upper and lower eyelids, superficial gland of the third eyelid, the third eyelid, deep gland of the third eyelid, and lacrimal gland in post-mortem specimens obtained from three captive aardvarks, two young and one adult. The obtained samples were analyzed using macroscopic, histological, and histochemical methods. We observed choroidal tapetum lucidum fibrosum in all specimens, which was typical for aardvarks. The superficial gland of the third eyelid was a compound multilobar tubular branched gland of a mucous nature. The deep gland of the third eyelid produced a serous secretion. The seromucous secretion was typical for the lacrimal gland. We compared the morphological data of the O. afer skull with that from other endemic African mammals in the Afrotheria clade. We found that other authors provided different anatomical names for some bones and foramina located within the orbit. The types and function of eyelid glands, as well as eyeball glands of aardvarks, can primarily be connected with their habitat. Our study may constitute an introduction to the ontogenesis of individual eyeball glands in aardvarks. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Wojciech Paszta
- Wrocław Zoological Garden, Wróblewskiego 1/5, Wrocław, Poland
| | - Joanna E Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska 1, Wrocław, Poland
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Kożuchowska 1, Wrocław, Poland
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4
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Deformity Index: A Semi-Reference Clade-Based Quality Metric of Phylogenetic Trees. J Mol Evol 2021; 89:302-312. [PMID: 33811501 DOI: 10.1007/s00239-021-10006-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 03/20/2021] [Indexed: 10/21/2022]
Abstract
Measuring the dissimilarity of a phylogenetic tree with respect to a reference tree or the hypotheses is a fundamental task in the phylogenetic study. A large number of methods have been proposed to compute the distance between the reference tree and the target tree. Due to the presence of unresolved relationships among the species, it is challenging to obtain a precise and an accurate reference tree for a selected dataset. As a result, the existing tree comparison methods may behave unexpectedly in various scenarios. In this paper, we introduce a novel scoring function, called the deformity index, to quantify the dissimilarity of a tree based on the list of clades of a reference tree. The strength of our proposed method is that it depends on the list of clades that can be acquired either from the reference tree or from the hypotheses. We investigate the distributions of different modules of the deformity index and perform different goodness-of-fit tests to understand the cumulative distribution. Then, we examine, in detail, the robustness as well as the scalability of our measure by performing different statistical tests under various models. Finally, we experiment on different biological datasets and show that our proposed scoring function overcomes the limitations of the conventional methods.
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Freitas LM, Dos Santos OP, Santos ALQ, de Melo FR, Silveira L, Jácomo ATDA, Pereira KF, Lima FC. Brain anatomy of two-toed sloth (Choloepus didactylus, Linnaeus, 1758): A comparative gross anatomical study of extant xenarthrans. Anat Histol Embryol 2019; 49:130-143. [PMID: 31588601 DOI: 10.1111/ahe.12501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 04/16/2019] [Accepted: 09/20/2019] [Indexed: 11/29/2022]
Abstract
The neural system plays an important role in understanding some features of animals. Anatomical complexity correlates with the increase of functional capacity. Xenarthrans include anteaters (Vermilingua), armadillos (Cingulata) and sloths (Folivora). This group is the base of eutherian mammals, and understanding the anatomy of its neural system could provide data for functional and evolutionary interpretations. The gross anatomy of the xenarthran brain is recorded. Four extant families of Pilosa and two families of Cingulata were sampled. Usual dissection procedures were used, and the brains were analysed macroscopically. The brain of two-toed sloth, three-toed sloth, six-banded armadillo, giant anteater and collared anteater are gyrencephalic. Pygmy anteater, nine-banded armadillo, great long-nosed armadillo, southern naked-tailed armadillo and giant armadillo are lissencephalic. In most species, the rhinal fissure presents two segments, rostral and caudal (except in Vermilingua and three-toed sloth). The diencephalon and brainstem present similar anatomy. The cerebellum is wide and presents four lobes (rostral, central, caudal and floccular). Its average volume is 12.16% (Folivora), 14.26% (Vermilingua) and 18.61% (Cingulata). Among these groups, there is a statistical difference between Folivora/Cingulata concerning the cerebellum average. The general pattern of the brain of the xenarthrans is similar to that of other mammals.
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Affiliation(s)
- Letícia Menezes Freitas
- Laboratory of Human and Comparative Anatomy, Department of Morphology, Biosciences Institute, Federal University of Goiás, Jataí, Brazil
| | - Odeony Paulo Dos Santos
- Laboratory of Genetics Diversity, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Brazil
| | - André Luiz Quagliatto Santos
- Wild Animal Research and Teaching Laboratory, Faculty of Veterinary Medicine, Federal University of Uberlândia, Uberlândia, Brazil
| | - Fabiano Rodrigues de Melo
- Laboratory of Human and Comparative Anatomy, Department of Morphology, Biosciences Institute, Federal University of Goiás, Jataí, Brazil
| | | | | | - Kleber Fernando Pereira
- Laboratory of Human and Comparative Anatomy, Department of Morphology, Biosciences Institute, Federal University of Goiás, Jataí, Brazil
| | - Fabiano Campos Lima
- Laboratory of Human and Comparative Anatomy, Department of Morphology, Biosciences Institute, Federal University of Goiás, Jataí, Brazil
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Goździewska-Harłajczuk K, Klećkowska-Nawrot J, Barszcz K. Macroscopic and microscopic study of the tongue of the aardvark (Orycteropus afer, Orycteropodidae). Tissue Cell 2018; 54:127-138. [DOI: 10.1016/j.tice.2018.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/29/2018] [Accepted: 08/29/2018] [Indexed: 01/02/2023]
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Phifer-Rixey M, Bi K, Ferris KG, Sheehan MJ, Lin D, Mack KL, Keeble SM, Suzuki TA, Good JM, Nachman MW. The genomic basis of environmental adaptation in house mice. PLoS Genet 2018; 14:e1007672. [PMID: 30248095 PMCID: PMC6171964 DOI: 10.1371/journal.pgen.1007672] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 10/04/2018] [Accepted: 08/30/2018] [Indexed: 01/18/2023] Open
Abstract
House mice (Mus musculus) arrived in the Americas only recently in association with European colonization (~400-600 generations), but have spread rapidly and show evidence of local adaptation. Here, we take advantage of this genetic model system to investigate the genomic basis of environmental adaptation in house mice. First, we documented clinal patterns of phenotypic variation in 50 wild-caught mice from a latitudinal transect in Eastern North America. Next, we found that progeny of mice from different latitudes, raised in a common laboratory environment, displayed differences in a number of complex traits related to fitness. Consistent with Bergmann's rule, mice from higher latitudes were larger and fatter than mice from lower latitudes. They also built bigger nests and differed in aspects of blood chemistry related to metabolism. Then, combining exomic, genomic, and transcriptomic data, we identified specific candidate genes underlying adaptive variation. In particular, we defined a short list of genes with cis-eQTL that were identified as candidates in exomic and genomic analyses, all of which have known ties to phenotypes that vary among the studied populations. Thus, wild mice and the newly developed strains represent a valuable resource for future study of the links between genetic variation, phenotypic variation, and climate.
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Affiliation(s)
- Megan Phifer-Rixey
- Department of Biology, Monmouth University, West Long Branch, New Jersey, United States of America
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
| | - Ke Bi
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
- Computational Genomics Resource Laboratory, California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, California, United States of America
| | - Kathleen G. Ferris
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
| | - Michael J. Sheehan
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
- Department of Neurobiology and Behavior, Cornell University, Ithaca, New York, United States of America
| | - Dana Lin
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
| | - Katya L. Mack
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
| | - Sara M. Keeble
- Division of Biological Sciences, University of Montana, Missoula, Missoula, Montana, United States of America
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, Los Angeles, California, United States of America
| | - Taichi A. Suzuki
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
| | - Jeffrey M. Good
- Division of Biological Sciences, University of Montana, Missoula, Missoula, Montana, United States of America
| | - Michael W. Nachman
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
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Coelho LP, Kultima JR, Costea PI, Fournier C, Pan Y, Czarnecki-Maulden G, Hayward MR, Forslund SK, Schmidt TSB, Descombes P, Jackson JR, Li Q, Bork P. Similarity of the dog and human gut microbiomes in gene content and response to diet. MICROBIOME 2018; 6:72. [PMID: 29669589 PMCID: PMC5907387 DOI: 10.1186/s40168-018-0450-3] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 03/19/2018] [Indexed: 05/19/2023]
Abstract
BACKGROUND Gut microbes influence their hosts in many ways, in particular by modulating the impact of diet. These effects have been studied most extensively in humans and mice. In this work, we used whole genome metagenomics to investigate the relationship between the gut metagenomes of dogs, humans, mice, and pigs. RESULTS We present a dog gut microbiome gene catalog containing 1,247,405 genes (based on 129 metagenomes and a total of 1.9 terabasepairs of sequencing data). Based on this catalog and taxonomic abundance profiling, we show that the dog microbiome is closer to the human microbiome than the microbiome of either pigs or mice. To investigate this similarity in terms of response to dietary changes, we report on a randomized intervention with two diets (high-protein/low-carbohydrate vs. lower protein/higher carbohydrate). We show that diet has a large and reproducible effect on the dog microbiome, independent of breed or sex. Moreover, the responses were in agreement with those observed in previous human studies. CONCLUSIONS We conclude that findings in dogs may be predictive of human microbiome results. In particular, a novel finding is that overweight or obese dogs experience larger compositional shifts than lean dogs in response to a high-protein diet.
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Affiliation(s)
- Luis Pedro Coelho
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jens Roat Kultima
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Paul Igor Costea
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | | | | | | | - Matthew Robert Hayward
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Sofia K. Forslund
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | | | | | | | | | - Peer Bork
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Max Delbrück Centre for Molecular Medicine, 13125 Berlin, Germany
- Department of Bioinformatics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
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Lundwall Å. Old genes and new genes: The evolution of the kallikrein locus. Thromb Haemost 2017; 110:469-75. [DOI: 10.1160/th12-11-0851] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/28/2013] [Indexed: 01/25/2023]
Abstract
SummaryThe human kallikrein locus consists of KLK1, the gene of major tissue kallikrein, and 14 genes of kallikrein-related peptidases (KLKs) located in tandem on chromosome 19q13.3-13.4. In this review, based on information retrieved from the literature or extracted from genome databases, it is hypothesised that the kallikrein locus is unique to mammals. The majority of genes are highly conserved, as demonstrated by the identification of 11 KLK genes in the opossum, a metatherian species. In contrast, a sublocus, encompassing KLK1-4, has gone through major transformations that have generated new genes, which in most cases are closely related to KLK1. In the primate lineage, this process created KLK3, the gene of the prostate cancer marker, prostate-specific antigen (PSA), whereas in the murine lineage it gave rise to 13 genes unique to the mouse and nine unique to the rat. The KLK proteases are effector molecules that emerged early in mammalian evolution and their importance in skin homeostasis and male reproductive function is undisputed and there are also accumulating evidence for a role of KLK proteases in the development of the brain. It is speculated that the KLK gene family arose as part of the process that generated distinguishing mammalian features, like skin with hair and sweat glands, and specialised anatomical attributes of the brain and the reproductive tract.
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Esselstyn JA, Oliveros CH, Swanson MT, Faircloth BC. Investigating Difficult Nodes in the Placental Mammal Tree with Expanded Taxon Sampling and Thousands of Ultraconserved Elements. Genome Biol Evol 2017; 9:2308-2321. [PMID: 28934378 PMCID: PMC5604124 DOI: 10.1093/gbe/evx168] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2017] [Indexed: 12/21/2022] Open
Abstract
The phylogeny of eutherian mammals contains some of the most recalcitrant nodes in the tetrapod tree of life. We combined comprehensive taxon and character sampling to explore three of the most debated interordinal relationships among placental mammals. We performed in silico extraction of ultraconserved element loci from 72 published genomes and invitro enrichment and sequencing of ultraconserved elements from 28 additional mammals, resulting in alignments of 3,787 loci. We analyzed these data using concatenated and multispecies coalescent phylogenetic approaches, topological tests, and exploration of support among individual loci to identify the root of Eutheria and the sister groups of tree shrews (Scandentia) and horses (Perissodactyla). Individual loci provided weak, but often consistent support for topological hypotheses. Although many gene trees lacked accepted species-tree relationships, summary coalescent topologies were largely consistent with inferences from concatenation. At the root of Eutheria, we identified consistent support for a sister relationship between Xenarthra and Afrotheria (i.e., Atlantogenata). At the other nodes of interest, support was less consistent. We suggest Scandentia is the sister of Primatomorpha (Euarchonta), but we failed to reject a sister relationship between Scandentia and Glires. Similarly, we suggest Perissodactyla is sister to Cetartiodactyla (Euungulata), but a sister relationship between Perissodactyla and Chiroptera remains plausible.
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Affiliation(s)
- Jacob A. Esselstyn
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
| | - Carl H. Oliveros
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
| | - Mark T. Swanson
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
| | - Brant C. Faircloth
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
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Esselstyn JA, Oliveros CH, Swanson MT, Faircloth BC. Investigating Difficult Nodes in the Placental Mammal Tree with Expanded Taxon Sampling and Thousands of Ultraconserved Elements. Genome Biol Evol 2017. [PMID: 28934378 DOI: 10.1093/gbe/evx168)] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The phylogeny of eutherian mammals contains some of the most recalcitrant nodes in the tetrapod tree of life. We combined comprehensive taxon and character sampling to explore three of the most debated interordinal relationships among placental mammals. We performed in silico extraction of ultraconserved element loci from 72 published genomes and invitro enrichment and sequencing of ultraconserved elements from 28 additional mammals, resulting in alignments of 3,787 loci. We analyzed these data using concatenated and multispecies coalescent phylogenetic approaches, topological tests, and exploration of support among individual loci to identify the root of Eutheria and the sister groups of tree shrews (Scandentia) and horses (Perissodactyla). Individual loci provided weak, but often consistent support for topological hypotheses. Although many gene trees lacked accepted species-tree relationships, summary coalescent topologies were largely consistent with inferences from concatenation. At the root of Eutheria, we identified consistent support for a sister relationship between Xenarthra and Afrotheria (i.e., Atlantogenata). At the other nodes of interest, support was less consistent. We suggest Scandentia is the sister of Primatomorpha (Euarchonta), but we failed to reject a sister relationship between Scandentia and Glires. Similarly, we suggest Perissodactyla is sister to Cetartiodactyla (Euungulata), but a sister relationship between Perissodactyla and Chiroptera remains plausible.
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Affiliation(s)
- Jacob A Esselstyn
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
| | - Carl H Oliveros
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
| | - Mark T Swanson
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
| | - Brant C Faircloth
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge
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12
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Genomic evidence reveals a radiation of placental mammals uninterrupted by the KPg boundary. Proc Natl Acad Sci U S A 2017; 114:E7282-E7290. [PMID: 28808022 DOI: 10.1073/pnas.1616744114] [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] [Indexed: 11/18/2022] Open
Abstract
The timing of the diversification of placental mammals relative to the Cretaceous-Paleogene (KPg) boundary mass extinction remains highly controversial. In particular, there have been seemingly irreconcilable differences in the dating of the early placental radiation not only between fossil-based and molecular datasets but also among molecular datasets. To help resolve this discrepancy, we performed genome-scale analyses using 4,388 loci from 90 taxa, including representatives of all extant placental orders and transcriptome data from flying lemurs (Dermoptera) and pangolins (Pholidota). Depending on the gene partitioning scheme, molecular clock model, and genic deviation from molecular clock assumptions, extensive sensitivity analyses recovered widely varying diversification scenarios for placental mammals from a given gene set, ranging from a deep Cretaceous origin and diversification to a scenario spanning the KPg boundary, suggesting that the use of suboptimal molecular clock markers and methodologies is a major cause of controversies regarding placental diversification timing. We demonstrate that reconciliation between molecular and paleontological estimates of placental divergence times can be achieved using the appropriate clock model and gene partitioning scheme while accounting for the degree to which individual genes violate molecular clock assumptions. A birth-death-shift analysis suggests that placental mammals underwent a continuous radiation across the KPg boundary without apparent interruption by the mass extinction, paralleling a genus-level radiation of multituberculates and ecomorphological diversification of both multituberculates and therians. These findings suggest that the KPg catastrophe evidently played a limited role in placental diversification, which, instead, was likely a delayed response to the slightly earlier radiation of angiosperms.
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Selvatti AP, Galvão A, Pereira AG, Pedreira Gonzaga L, Russo CADM. An African Origin of the Eurylaimides (Passeriformes) and the Successful Diversification of the Ground-Foraging Pittas (Pittidae). Mol Biol Evol 2017; 34:483-499. [PMID: 28069777 DOI: 10.1093/molbev/msw250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The Eurylaimides is one of the few passerine groups with a pantropical distribution. In this study, we generated a multi-calibrated tree with 83% of eurylaimid species diversity based on 30 molecular loci. Particular attention was given to the monotypic Sapayoidae to reconstruct the biogeography of this radiation. We conducted several topological tests including nonoverlapping subsampling of the concatenated alignment and coalescent species tree reconstruction. These tests firmly placed the South American Sapayoidae as the sister group to all other Eurylaimides families (split at ∼28 Ma), with increasing branch support as highly variable sites were removed. This topology is consistent with the breakup of the insular connection between Africa and South America (Atlantogea) that took place between the middle Eocene and the early Oligocene. We recovered Africa as the cradle of the core Eurylaimides, and this result is supported by all African lineages corresponding to the oldest splits within each family in this group. Our timescale suggests that desertification and the uplift of the Tibetan Plateau caused a parallel divergence between African and Asian lineages in all major clades in the core Eurylaimides at 22-9 Ma. We also propose that the ground-foraging behavior in the Pittidae ancestor allowed the pitta lineage to thrive and coexist with the older arboreal lineages of the core Eurylaimides. In contrast, the diversification of pittas in Australia was likely hindered by direct competition with the endemic ground-foraging oscines that had been well established in that continent since the Eocene.
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Affiliation(s)
- Alexandre Pedro Selvatti
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Instituto de Biologia, Rio de Janeiro, RJ, Brazil
| | - Ana Galvão
- Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Anieli Guirro Pereira
- Departamento de Genética, Universidade Federal do Rio de Janeiro, Instituto de Biologia, Rio de Janeiro, RJ, Brazil
| | - Luiz Pedreira Gonzaga
- Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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14
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Feijoo M, Parada A. Macrosystematics of eutherian mammals combining HTS data to expand taxon coverage. Mol Phylogenet Evol 2017; 113:76-83. [PMID: 28487261 DOI: 10.1016/j.ympev.2017.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 05/04/2017] [Accepted: 05/04/2017] [Indexed: 02/04/2023]
Abstract
In the last few years high-throughput sequencing technologies have permitted significant advances in mammalian phylogenetic studies from a genomic perspective. However, these studies have been restricted to a sparse number of species with available reference genomes. Thus, several issues inside the eutherian mammals phylogeny remain unresolved. This may be due in part to limited taxon sampling, as taxonomic density is known to affect phylogenetic resolution. In this context, we present a protocol to increase taxon coverage using high-throughput sequencing data (RNA or DNA) generated for other biological studies and available in public databases. Following this procedure we addressed pending or controversial issues concerning the phylogenetic position of Dermoptera, Pholidota and Chiroptera, considering multiple and independent loci. Also for Chiroptera and Arctoidea we evaluated the relationships of the lineages that compose it. Although the maximum number of genes used is moderate (95), in some cases taxon coverage doubles that of previous related studies. Globally, all coalescent-based (STAR, MP-EST and ASTRAL) and concatenated (IQ-TREE and BEAST2) methods used for species tree reconstruction were consistent to each other and most of interrogated nodes received high statistical support.
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Affiliation(s)
- M Feijoo
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo CP 11400, Uruguay.
| | - A Parada
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia CP 5090000, Chile.
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15
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Halliday TJD, Upchurch P, Goswami A. Resolving the relationships of Paleocene placental mammals. Biol Rev Camb Philos Soc 2017; 92:521-550. [PMID: 28075073 PMCID: PMC6849585 DOI: 10.1111/brv.12242] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 10/28/2015] [Accepted: 11/04/2015] [Indexed: 01/25/2023]
Abstract
The 'Age of Mammals' began in the Paleocene epoch, the 10 million year interval immediately following the Cretaceous-Palaeogene mass extinction. The apparently rapid shift in mammalian ecomorphs from small, largely insectivorous forms to many small-to-large-bodied, diverse taxa has driven a hypothesis that the end-Cretaceous heralded an adaptive radiation in placental mammal evolution. However, the affinities of most Paleocene mammals have remained unresolved, despite significant advances in understanding the relationships of the extant orders, hindering efforts to reconstruct robustly the origin and early evolution of placental mammals. Here we present the largest cladistic analysis of Paleocene placentals to date, from a data matrix including 177 taxa (130 of which are Palaeogene) and 680 morphological characters. We improve the resolution of the relationships of several enigmatic Paleocene clades, including families of 'condylarths'. Protungulatum is resolved as a stem eutherian, meaning that no crown-placental mammal unambiguously pre-dates the Cretaceous-Palaeogene boundary. Our results support an Atlantogenata-Boreoeutheria split at the root of crown Placentalia, the presence of phenacodontids as closest relatives of Perissodactyla, the validity of Euungulata, and the placement of Arctocyonidae close to Carnivora. Periptychidae and Pantodonta are resolved as sister taxa, Leptictida and Cimolestidae are found to be stem eutherians, and Hyopsodontidae is highly polyphyletic. The inclusion of Paleocene taxa in a placental phylogeny alters interpretations of relationships and key events in mammalian evolutionary history. Paleocene mammals are an essential source of data for understanding fully the biotic dynamics associated with the end-Cretaceous mass extinction. The relationships presented here mark a critical first step towards accurate reconstruction of this important interval in the evolution of the modern fauna.
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Affiliation(s)
- Thomas J. D. Halliday
- Department of Earth SciencesUniversity College LondonGower StreetLondonWC1E 6BTU.K.
- Department of Genetics, Evolution and EnvironmentUniversity College LondonGower StreetLondonWC1E 6BTU.K.
| | - Paul Upchurch
- Department of Earth SciencesUniversity College LondonGower StreetLondonWC1E 6BTU.K.
| | - Anjali Goswami
- Department of Earth SciencesUniversity College LondonGower StreetLondonWC1E 6BTU.K.
- Department of Genetics, Evolution and EnvironmentUniversity College LondonGower StreetLondonWC1E 6BTU.K.
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16
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O'Connor A, Wills MA. Measuring Stratigraphic Congruence Across Trees, Higher Taxa, and Time. Syst Biol 2016; 65:792-811. [PMID: 27155010 PMCID: PMC4997008 DOI: 10.1093/sysbio/syw039] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 05/03/2016] [Indexed: 11/30/2022] Open
Abstract
The congruence between the order of cladistic branching and the first appearance dates of fossil lineages can be quantified using a variety of indices. Good matching is a prerequisite for the accurate time calibration of trees, while the distribution of congruence indices across large samples of cladograms has underpinned claims about temporal and taxonomic patterns of completeness in the fossil record. The most widely used stratigraphic congruence indices are the stratigraphic consistency index (SCI), the modified Manhattan stratigraphic measure (MSM*), and the gap excess ratio (GER) (plus its derivatives; the topological GER and the modified GER). Many factors are believed to variously bias these indices, with several empirical and simulation studies addressing some subset of the putative interactions. This study combines both approaches to quantify the effects (on all five indices) of eight variables reasoned to constrain the distribution of possible values (the number of taxa, tree balance, tree resolution, range of first occurrence (FO) dates, center of gravity of FO dates, the variability of FO dates, percentage of extant taxa, and percentage of taxa with no fossil record). Our empirical data set comprised 647 published animal and plant cladograms spanning the entire Phanerozoic, and for these data we also modeled the effects of mean age of FOs (as a proxy for clade age), the taxonomic rank of the clade, and the higher taxonomic group to which it belonged. The center of gravity of FO dates had not been investigated hitherto, and this was found to correlate most strongly with some measures of stratigraphic congruence in our empirical study (top-heavy clades had better congruence). The modified GER was the index least susceptible to bias. We found significant differences across higher taxa for all indices; arthropods had lower congruence and tetrapods higher congruence. Stratigraphic congruence-however measured-also varied throughout the Phanerozoic, reflecting the taxonomic composition of our sample. Notably, periods containing a high proportion of arthropods had poorer congruence overall than those with higher proportions of tetrapods. [Fossil calibration; gap excess ratio; manhattan stratigraphic metric; molecular clocks; stratigraphic congruence.].
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Affiliation(s)
- Anne O'Connor
- Milner Centre for Evolution, The University of Bath, The Avenue, Claverton Down, Bath BA2 7AY, UK
| | - Matthew A Wills
- Milner Centre for Evolution, The University of Bath, The Avenue, Claverton Down, Bath BA2 7AY, UK
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17
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Foley NM, Springer MS, Teeling EC. Mammal madness: is the mammal tree of life not yet resolved? Philos Trans R Soc Lond B Biol Sci 2016; 371:20150140. [PMID: 27325836 PMCID: PMC4920340 DOI: 10.1098/rstb.2015.0140] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2016] [Indexed: 11/12/2022] Open
Abstract
Most molecular phylogenetic studies place all placental mammals into four superordinal groups, Laurasiatheria (e.g. dogs, bats, whales), Euarchontoglires (e.g. humans, rodents, colugos), Xenarthra (e.g. armadillos, anteaters) and Afrotheria (e.g. elephants, sea cows, tenrecs), and estimate that these clades last shared a common ancestor 90-110 million years ago. This phylogeny has provided a framework for numerous functional and comparative studies. Despite the high level of congruence among most molecular studies, questions still remain regarding the position and divergence time of the root of placental mammals, and certain 'hard nodes' such as the Laurasiatheria polytomy and Paenungulata that seem impossible to resolve. Here, we explore recent consensus and conflict among mammalian phylogenetic studies and explore the reasons for the remaining conflicts. The question of whether the mammal tree of life is or can be ever resolved is also addressed.This article is part of the themed issue 'Dating species divergences using rocks and clocks'.
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Affiliation(s)
- Nicole M Foley
- School of Biology and Environmental Science, Science Centre East, University College Dublin, Dublin 4, Ireland
| | - Mark S Springer
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Emma C Teeling
- School of Biology and Environmental Science, Science Centre East, University College Dublin, Dublin 4, Ireland
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18
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Reyes LD, Harland T, Reep RL, Sherwood CC, Jacobs B. Golgi Analysis of Neuron Morphology in the Presumptive Somatosensory Cortex and Visual Cortex of the Florida Manatee (Trichechus manatus latirostris). BRAIN, BEHAVIOR AND EVOLUTION 2016; 87:105-16. [PMID: 27166161 DOI: 10.1159/000445495] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/15/2016] [Indexed: 11/19/2022]
Abstract
The current study investigates neuron morphology in presumptive primary somatosensory (S1) and primary visual (V1) cortices of the Florida manatee (Trichechus manatus latirostris) as revealed by Golgi impregnation. Sirenians, including manatees, have an aquatic lifestyle, a large body size, and a relatively large lissencephalic brain. The present study examines neuron morphology in 3 cortical areas: in S1, dorsolateral cortex area 1 (DL1) and cluster cortex area 2 (CL2) and in V1, dorsolateral cortex area 4 (DL4). Neurons exhibited a variety of morphological types, with pyramidal neurons being the most common. The large variety of neuron types present in the manatee cortex was comparable to that seen in other eutherian mammals, except for rodents and primates, where pyramid-shaped neurons predominate. A comparison between pyramidal neurons in S1 and V1 indicated relatively greater dendritic branching in S1. Across all 3 areas, the dendritic arborization pattern of pyramidal neurons was also similar to that observed previously in the afrotherian rock hyrax, cetartiodactyls, opossums, and echidnas but did not resemble the widely bifurcated dendrites seen in the large-brained African elephant. Despite adaptations for an aquatic environment, manatees did not share specific neuron types such as tritufted and star-like neurons that have been found in cetaceans. Manatees exhibit an evolutionarily primitive pattern of cortical neuron morphology shared with most other mammals and do not appear to have neuronal specializations for an aquatic niche.
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Affiliation(s)
- Laura D Reyes
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, D.C., USA
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19
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Buckley M. Ancient collagen reveals evolutionary history of the endemic South American 'ungulates'. Proc Biol Sci 2016; 282:20142671. [PMID: 25833851 PMCID: PMC4426609 DOI: 10.1098/rspb.2014.2671] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Since the late eighteenth century, fossils of bizarre extinct creatures have been described from the Americas, revealing a previously unimagined chapter in the history of mammals. The most bizarre of these are the ‘native’ South American ungulates thought to represent a group of mammals that evolved in relative isolation on South America, but with an uncertain affinity to any particular placental lineage. Many authors have considered them descended from Laurasian ‘condylarths’, which also includes the probable ancestors of perissodactyls and artiodactyls, whereas others have placed them either closer to the uniquely South American xenarthrans (anteaters, armadillos and sloths) or the basal afrotherians (e.g. elephants and hyraxes). These hypotheses have been debated owing to conflicting morphological characteristics and the hitherto inability to retrieve molecular information. Of the ‘native’ South American mammals, only the toxodonts and litopterns persisted until the Late Pleistocene–Early Holocene. Owing to known difficulties in retrieving ancient DNA (aDNA) from specimens from warm climates, this research presents a molecular phylogeny for both Macrauchenia patachonica (Litopterna) and Toxodon platensis (Notoungulata) recovered using proteomics-based (liquid chromatography–tandem mass spectrometry) sequencing analyses of bone collagen. The results place both taxa in a clade that is monophyletic with the perissodactyls, which today are represented by horses, rhinoceroses and tapirs.
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Affiliation(s)
- Michael Buckley
- Faculty of Life Sciences, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK
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20
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Naumann RK, Ray S, Prokop S, Las L, Heppner FL, Brecht M. Conserved size and periodicity of pyramidal patches in layer 2 of medial/caudal entorhinal cortex. J Comp Neurol 2016; 524:783-806. [PMID: 26223342 PMCID: PMC5014138 DOI: 10.1002/cne.23865] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/16/2015] [Accepted: 07/17/2015] [Indexed: 11/29/2022]
Abstract
To understand the structural basis of grid cell activity, we compare medial entorhinal cortex architecture in layer 2 across five mammalian species (Etruscan shrews, mice, rats, Egyptian fruit bats, and humans), bridging ∼100 million years of evolutionary diversity. Principal neurons in layer 2 are divided into two distinct cell types, pyramidal and stellate, based on morphology, immunoreactivity, and functional properties. We confirm the existence of patches of calbindin-positive pyramidal cells across these species, arranged periodically according to analyses techniques like spatial autocorrelation, grid scores, and modifiable areal unit analysis. In rodents, which show sustained theta oscillations in entorhinal cortex, cholinergic innervation targeted calbindin patches. In bats and humans, which only show intermittent entorhinal theta activity, cholinergic innervation avoided calbindin patches. The organization of calbindin-negative and calbindin-positive cells showed marked differences in entorhinal subregions of the human brain. Layer 2 of the rodent medial and the human caudal entorhinal cortex were structurally similar in that in both species patches of calbindin-positive pyramidal cells were superimposed on scattered stellate cells. The number of calbindin-positive neurons in a patch increased from ∼80 in Etruscan shrews to ∼800 in humans, only an ∼10-fold over a 20,000-fold difference in brain size. The relatively constant size of calbindin patches differs from cortical modules such as barrels, which scale with brain size. Thus, selective pressure appears to conserve the distribution of stellate and pyramidal cells, periodic arrangement of calbindin patches, and relatively constant neuron number in calbindin patches in medial/caudal entorhinal cortex.
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Affiliation(s)
- Robert K. Naumann
- Bernstein Center for Computational NeuroscienceHumboldt University of Berlin10115BerlinGermany
- Max‐Planck‐Institute for Brain ResearchMax‐von‐Laue‐Str. 460438Frankfurt am MainGermany
| | - Saikat Ray
- Bernstein Center for Computational NeuroscienceHumboldt University of Berlin10115BerlinGermany
| | - Stefan Prokop
- Neuropathology Institute, Charité Medical School10117BerlinGermany
| | - Liora Las
- Department of NeurobiologyWeizmann Institute of ScienceRehovot76100Israel
| | - Frank L. Heppner
- Neuropathology Institute, Charité Medical School10117BerlinGermany
| | - Michael Brecht
- Bernstein Center for Computational NeuroscienceHumboldt University of Berlin10115BerlinGermany
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21
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Frankenberg SR, de Barros FR, Rossant J, Renfree MB. The mammalian blastocyst. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:210-32. [DOI: 10.1002/wdev.220] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 10/22/2015] [Accepted: 10/29/2015] [Indexed: 11/10/2022]
Affiliation(s)
| | - Flavia R.O. de Barros
- Program in Developmental and Stem Cell Biology; Peter Gilgan Centre for Research and Learning, Hospital for Sick Children; Toronto Canada
- Department of Molecular Genetics; University of Toronto; Toronto Canada
| | - Janet Rossant
- Program in Developmental and Stem Cell Biology; Peter Gilgan Centre for Research and Learning, Hospital for Sick Children; Toronto Canada
- Department of Molecular Genetics; University of Toronto; Toronto Canada
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22
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Reyes LD, Stimpson CD, Gupta K, Raghanti MA, Hof PR, Reep RL, Sherwood CC. Neuron Types in the Presumptive Primary Somatosensory Cortex of the Florida Manatee (Trichechus manatus latirostris). BRAIN, BEHAVIOR AND EVOLUTION 2015; 86:210-31. [PMID: 26613530 DOI: 10.1159/000441964] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 10/25/2015] [Indexed: 11/19/2022]
Abstract
Within afrotherians, sirenians are unusual due to their aquatic lifestyle, large body size and relatively large lissencephalic brain. However, little is known about the neuron type distributions of the cerebral cortex in sirenians within the context of other afrotherians and aquatic mammals. The present study investigated two cortical regions, dorsolateral cortex area 1 (DL1) and cluster cortex area 2 (CL2), in the presumptive primary somatosensory cortex (S1) in Florida manatees (Trichechus manatus latirostris) to characterize cyto- and chemoarchitecture. The mean neuron density for both cortical regions was 35,617 neurons/mm(3) and fell within the 95% prediction intervals relative to brain mass based on a reference group of afrotherians and xenarthrans. Densities of inhibitory interneuron subtypes labeled against calcium-binding proteins and neuropeptide Y were relatively low compared to afrotherians and xenarthrans and also formed a small percentage of the overall population of inhibitory interneurons as revealed by GAD67 immunoreactivity. Nonphosphorylated neurofilament protein-immunoreactive (NPNFP-ir) neurons comprised a mean of 60% of neurons in layer V across DL1 and CL2. DL1 contained a higher percentage of NPNFP-ir neurons than CL2, although CL2 had a higher variety of morphological types. The mean percentage of NPNFP-ir neurons in the two regions of the presumptive S1 were low compared to other afrotherians and xenarthrans but were within the 95% prediction intervals relative to brain mass, and their morphologies were comparable to those found in other afrotherians and xenarthrans. Although this specific pattern of neuron types and densities sets the manatee apart from other afrotherians and xenarthrans, the manatee isocortex does not appear to be explicitly adapted for an aquatic habitat. Many of the features that are shared between manatees and cetaceans are also shared with a diverse array of terrestrial mammals and likely represent highly conserved neural features. A comparative study across manatees and dugongs is necessary to determine whether these traits are specific to one or more of the manatee species, or can be generalized to all sirenians.
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Affiliation(s)
- Laura D Reyes
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, D.C., USA
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23
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Buckley M, Fariña RA, Lawless C, Tambusso PS, Varela L, Carlini AA, Powell JE, Martinez JG. Collagen Sequence Analysis of the Extinct Giant Ground Sloths Lestodon and Megatherium. PLoS One 2015; 10:e0139611. [PMID: 26540101 PMCID: PMC4634953 DOI: 10.1371/journal.pone.0139611] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/14/2015] [Indexed: 11/19/2022] Open
Abstract
For over 200 years, fossils of bizarre extinct creatures have been described from the Americas that have ranged from giant ground sloths to the ‘native’ South American ungulates, groups of mammals that evolved in relative isolation on South America. Ground sloths belong to the South American xenarthrans, a group with modern although morphologically and ecologically very different representatives (anteaters, armadillos and sloths), which has been proposed to be one of the four main eutherian clades. Recently, proteomics analyses of bone collagen have recently been used to yield a molecular phylogeny for a range of mammals including the unusual ‘Malagasy aardvark’ shown to be most closely related to the afrotherian tenrecs, and the south American ungulates supporting their morphological association with condylarths. However, proteomics results generate partial sequence information that could impact upon the phylogenetic placement that has not been appropriately tested. For comparison, this paper examines the phylogenetic potential of proteomics-based sequencing through the analysis of collagen extracted from two extinct giant ground sloths, Lestodon and Megatherium. The ground sloths were placed as sister taxa to extant sloths, but with a closer relationship between Lestodon and the extant sloths than the basal Megatherium. These results highlight that proteomics methods could yield plausible phylogenies that share similarities with other methods, but have the potential to be more useful in fossils beyond the limits of ancient DNA survival.
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Affiliation(s)
- Michael Buckley
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, United Kingdom
- * E-mail:
| | - Richard A. Fariña
- Sección Paleontología, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, Uruguay
| | - Craig Lawless
- Michael Smith Building, The University of Manchester, Manchester, United Kingdom
| | - P. Sebastián Tambusso
- Sección Paleontología, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, Uruguay
| | - Luciano Varela
- Sección Paleontología, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, Uruguay
| | - Alfredo A. Carlini
- Facultad de Ciencias Naturales y Museo, Museo de La Plata, Buenos Aires, Argentina
| | - Jaime E. Powell
- Facultad de Ciencias Naturales, Universidad Nacional de Tucumán, Tucumán Province, Argentina
| | - Jorge G. Martinez
- Instituto Superior de Estudios Sociales-CONICET, Instituto de Arqueología y Museo-UNT, Tucumán Province, Argentina
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24
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Pardi F, Scornavacca C. Reconstructible phylogenetic networks: do not distinguish the indistinguishable. PLoS Comput Biol 2015; 11:e1004135. [PMID: 25849429 PMCID: PMC4388854 DOI: 10.1371/journal.pcbi.1004135] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 01/19/2015] [Indexed: 12/21/2022] Open
Abstract
Phylogenetic networks represent the evolution of organisms that have undergone reticulate events, such as recombination, hybrid speciation or lateral gene transfer. An important way to interpret a phylogenetic network is in terms of the trees it displays, which represent all the possible histories of the characters carried by the organisms in the network. Interestingly, however, different networks may display exactly the same set of trees, an observation that poses a problem for network reconstruction: from the perspective of many inference methods such networks are "indistinguishable". This is true for all methods that evaluate a phylogenetic network solely on the basis of how well the displayed trees fit the available data, including all methods based on input data consisting of clades, triples, quartets, or trees with any number of taxa, and also sequence-based approaches such as popular formalisations of maximum parsimony and maximum likelihood for networks. This identifiability problem is partially solved by accounting for branch lengths, although this merely reduces the frequency of the problem. Here we propose that network inference methods should only attempt to reconstruct what they can uniquely identify. To this end, we introduce a novel definition of what constitutes a uniquely reconstructible network. For any given set of indistinguishable networks, we define a canonical network that, under mild assumptions, is unique and thus representative of the entire set. Given data that underwent reticulate evolution, only the canonical form of the underlying phylogenetic network can be uniquely reconstructed. While on the methodological side this will imply a drastic reduction of the solution space in network inference, for the study of reticulate evolution this is a fundamental limitation that will require an important change of perspective when interpreting phylogenetic networks.
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Affiliation(s)
- Fabio Pardi
- Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier (LIRMM, UMR 5506) CNRS, Université de Montpellier, France
- Institut de Biologie Computationnelle, Montpellier, France
| | - Celine Scornavacca
- Institut des Sciences de l’Evolution de Montpellier (ISE-M, UMR 5554) CNRS, IRD, Université de Montpellier, France
- Institut de Biologie Computationnelle, Montpellier, France
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25
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Averianov AO, Lopatin AV. High-level systematics of placental mammals: Current status of the problem. BIOL BULL+ 2014. [DOI: 10.1134/s1062359014090039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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When xenarthrans had enamel: insights on the evolution of their hypsodonty and paleontological support for independent evolution in armadillos. Naturwissenschaften 2014; 101:715-25. [DOI: 10.1007/s00114-014-1208-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 06/26/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
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27
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Enk JM, Devault AM, Kuch M, Murgha YE, Rouillard JM, Poinar HN. Ancient whole genome enrichment using baits built from modern DNA. Mol Biol Evol 2014; 31:1292-4. [PMID: 24531081 DOI: 10.1093/molbev/msu074] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
We report metrics from complete genome capture of nuclear DNA from extinct mammoths using biotinylated RNAs transcribed from an Asian elephant DNA extract. Enrichment of the nuclear genome ranged from 1.06- to 18.65-fold, to an apparent maximum threshold of ∼80% on-target. This projects an order of magnitude less costly complete genome sequencing from long-dead organisms, even when a reference genome is unavailable for bait design.
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Affiliation(s)
- Jacob M Enk
- McMaster Ancient DNA Centre, Department of Anthropology, McMaster University, Hamilton, ON, Canada
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Aguiar BO, Schrago CG. Conventional simulation of biological sequences leads to a biased assessment of multi-Loci phylogenetic analysis. Evol Bioinform Online 2013; 9:317-25. [PMID: 23997573 PMCID: PMC3748088 DOI: 10.4137/ebo.s12483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Phylogenetic analysis based on multi-loci data sets is performed by means of supermatrix (SM) or supertree (ST) approaches. Recently, methods that rely on species tree (SppT) inference by the multi-species coalescence have also been implemented to tackle this problem. Generally, the relative performance of these three major strategies has been calculated using simulation of biological sequences. However, sequence simulation may not entirely replicate the complexity of the evolutionary process. Thus, issues regarding the usefulness of in silico sequences in studying the performance of phylogenetic methods have been raised. Here, we used both classical simulation and empirical data to investigate the relative performance of ST, SM, and the SppT methods. SM analyses performed better than the ST and SppTs in simulations, but not in empirical analyses where some ST methods significantly outperformed the others. Additionally, SM was the only method that was robust under evolutionary model violations in simulations. These results show that conventional biological sequence simulation cannot adequately resolve which method is most efficient to recover the SppT. In such simulations, the SM approach recovers the established phylogeny in most instances, whereas the performance of the ST and SppT methods is downgraded in simpler cases. When compared, the analyses based on empirical and simulated sequences yielded largely inconsistent results, with the latter showing a bias towards a seemingly superiority of SM approaches.
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Affiliation(s)
- Barbara O Aguiar
- Department of Genetics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Morgan CC, Foster PG, Webb AE, Pisani D, McInerney JO, O'Connell MJ. Heterogeneous models place the root of the placental mammal phylogeny. Mol Biol Evol 2013; 30:2145-56. [PMID: 23813979 PMCID: PMC3748356 DOI: 10.1093/molbev/mst117] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Heterogeneity among life traits in mammals has resulted in considerable phylogenetic conflict, particularly concerning the position of the placental root. Layered upon this are gene- and lineage-specific variation in amino acid substitution rates and compositional biases. Life trait variations that may impact upon mutational rates are longevity, metabolic rate, body size, and germ line generation time. Over the past 12 years, three main conflicting hypotheses have emerged for the placement of the placental root. These hypotheses place the Atlantogenata (common ancestor of Xenarthra plus Afrotheria), the Afrotheria, or the Xenarthra as the sister group to all other placental mammals. Model adequacy is critical for accurate tree reconstruction and by failing to account for these compositional and character exchange heterogeneities across the tree and data set, previous studies have not provided a strongly supported hypothesis for the placental root. For the first time, models that accommodate both tree and data set heterogeneity have been applied to mammal data. Here, we show the impact of accurate model assignment and the importance of data sets in accommodating model parameters while maintaining the power to reject competing hypotheses. Through these sophisticated methods, we demonstrate the importance of model adequacy, data set power and provide strong support for the Atlantogenata over other competing hypotheses for the position of the placental root.
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Affiliation(s)
- Claire C Morgan
- Bioinformatics and Molecular Evolution Group, School of Biotechnology, Dublin City University, Glasnevin, Dublin, Ireland
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Romiguier J, Ranwez V, Delsuc F, Galtier N, Douzery EJP. Less is more in mammalian phylogenomics: AT-rich genes minimize tree conflicts and unravel the root of placental mammals. Mol Biol Evol 2013; 30:2134-44. [PMID: 23813978 DOI: 10.1093/molbev/mst116] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Despite the rapid increase of size in phylogenomic data sets, a number of important nodes on animal phylogeny are still unresolved. Among these, the rooting of the placental mammal tree is still a controversial issue. One difficulty lies in the pervasive phylogenetic conflicts among genes, with each one telling its own story, which may be reliable or not. Here, we identified a simple criterion, that is, the GC content, which substantially helps in determining which gene trees best reflect the species tree. We assessed the ability of 13,111 coding sequence alignments to correctly reconstruct the placental phylogeny. We found that GC-rich genes induced a higher amount of conflict among gene trees and performed worse than AT-rich genes in retrieving well-supported, consensual nodes on the placental tree. We interpret this GC effect mainly as a consequence of genome-wide variations in recombination rate. Indeed, recombination is known to drive GC-content evolution through GC-biased gene conversion and might be problematic for phylogenetic reconstruction, for instance, in an incomplete lineage sorting context. When we focused on the AT-richest fraction of the data set, the resolution level of the placental phylogeny was greatly increased, and a strong support was obtained in favor of an Afrotheria rooting, that is, Afrotheria as the sister group of all other placentals. We show that in mammals most conflicts among gene trees, which have so far hampered the resolution of the placental tree, are concentrated in the GC-rich regions of the genome. We argue that the GC content-because it is a reliable indicator of the long-term recombination rate-is an informative criterion that could help in identifying the most reliable molecular markers for species tree inference.
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Affiliation(s)
- Jonathan Romiguier
- CNRS, Université Montpellier, Institut des Sciences de l'Evolution, Montpellier, France.
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Struck TH. The impact of paralogy on phylogenomic studies - a case study on annelid relationships. PLoS One 2013; 8:e62892. [PMID: 23667537 PMCID: PMC3647064 DOI: 10.1371/journal.pone.0062892] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 03/26/2013] [Indexed: 12/15/2022] Open
Abstract
Phylogenomic studies based on hundreds of genes derived from expressed sequence tags libraries are increasingly used to reveal the phylogeny of taxa. A prerequisite for these studies is the assignment of genes into clusters of orthologous sequences. Sophisticated methods of orthology prediction are used in such analyses, but it is rarely assessed whether paralogous sequences have been erroneously grouped together as orthologous sequences after the prediction, and whether this had an impact on the phylogenetic reconstruction using a super-matrix approach. Herein, I tested the impact of paralogous sequences on the reconstruction of annelid relationships based on phylogenomic datasets. Using single-partition analyses, screening for bootstrap support, blast searches and pruning of sequences in the supermatrix, wrongly assigned paralogous sequences were found in eight partitions and the placement of five taxa (the annelids Owenia, Scoloplos, Sthenelais and Eurythoe and the nemertean Cerebratulus) including the robust bootstrap support could be attributed to the presence of paralogous sequences in two partitions. Excluding these sequences resulted in a different, weaker supported placement for these taxa. Moreover, the analyses revealed that paralogous sequences impacted the reconstruction when only a single taxon represented a previously supported higher taxon such as a polychaete family. One possibility of a priori detection of wrongly assigned paralogous sequences could combine 1) a screening of single-partition analyses based on criteria such as nodal support or internal branch length with 2) blast searches of suspicious cases as presented herein. Also possible are a posteriori approaches in which support for specific clades is investigated by comparing alternative hypotheses based on differences in per-site likelihoods. Increasing the sizes of EST libraries will also decrease the likelihood of wrongly assigned paralogous sequences, and in the case of orthology prediction methods like HaMStR it is likewise decreased by using more than one reference taxon.
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Coalescent-based genome analyses resolve the early branches of the euarchontoglires. PLoS One 2013; 8:e60019. [PMID: 23560065 PMCID: PMC3613385 DOI: 10.1371/journal.pone.0060019] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 02/20/2013] [Indexed: 11/19/2022] Open
Abstract
Despite numerous large-scale phylogenomic studies, certain parts of the mammalian tree are extraordinarily difficult to resolve. We used the coding regions from 19 completely sequenced genomes to study the relationships within the super-clade Euarchontoglires (Primates, Rodentia, Lagomorpha, Dermoptera and Scandentia) because the placement of Scandentia within this clade is controversial. The difficulty in resolving this issue is due to the short time spans between the early divergences of Euarchontoglires, which may cause incongruent gene trees. The conflict in the data can be depicted by network analyses and the contentious relationships are best reconstructed by coalescent-based analyses. This method is expected to be superior to analyses of concatenated data in reconstructing a species tree from numerous gene trees. The total concatenated dataset used to study the relationships in this group comprises 5,875 protein-coding genes (9,799,170 nucleotides) from all orders except Dermoptera (flying lemurs). Reconstruction of the species tree from 1,006 gene trees using coalescent models placed Scandentia as sister group to the primates, which is in agreement with maximum likelihood analyses of concatenated nucleotide sequence data. Additionally, both analytical approaches favoured the Tarsier to be sister taxon to Anthropoidea, thus belonging to the Haplorrhine clade. When divergence times are short such as in radiations over periods of a few million years, even genome scale analyses struggle to resolve phylogenetic relationships. On these short branches processes such as incomplete lineage sorting and possibly hybridization occur and make it preferable to base phylogenomic analyses on coalescent methods.
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Hautier L, Bennett NC, Viljoen H, Howard L, Milinkovitch MC, Tzika AC, Goswami A, Asher RJ. PATTERNS OF OSSIFICATION IN SOUTHERN VERSUS NORTHERN PLACENTAL MAMMALS. Evolution 2013; 67:1994-2010. [DOI: 10.1111/evo.12071] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 01/31/2013] [Indexed: 12/01/2022]
Affiliation(s)
- Lionel Hautier
- Department of Zoology; University of Cambridge; Downing St. Cambridge CB2 3EJ United Kingdom
| | - Nigel C. Bennett
- Department of Zoology and Entomology; University of Pretoria; Pretoria 0002 South Africa
| | - Hermien Viljoen
- Department of Zoology and Entomology; University of Pretoria; Pretoria 0002 South Africa
| | - Lauren Howard
- Science Facilities Department; British Museum of Natural History; Cromwell Road London SW7 5BD United Kingdom
| | - Michel C. Milinkovitch
- Laboratory of Artificial and Natural Evolution; Department of Genetics & Evolution; Sciences III Building; 30 Quai Ernest-Ansermet 1211 Geneva Switzerland
| | - Athanasia C. Tzika
- Laboratory of Artificial and Natural Evolution; Department of Genetics & Evolution; Sciences III Building; 30 Quai Ernest-Ansermet 1211 Geneva Switzerland
| | - Anjali Goswami
- Department of Genetics, Evolution, and Environment and Department of Earth Sciences; University College London; Wolfson House to Darwin Building; Gower Street London WC1E 6BT United Kingdom
| | - Robert J. Asher
- Department of Zoology; University of Cambridge; Downing St. Cambridge CB2 3EJ United Kingdom
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Johnson KP, Walden KK, Robertson HM. Next-generation phylogenomics using a Target Restricted Assembly Method. Mol Phylogenet Evol 2013; 66:417-22. [DOI: 10.1016/j.ympev.2012.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 09/07/2012] [Accepted: 09/10/2012] [Indexed: 11/25/2022]
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Luo H, Arndt W, Zhang Y, Shi G, Alekseyev M, Tang J, Hughes AL, Friedman R. Phylogenetic analysis of genome rearrangements among five mammalian orders. Mol Phylogenet Evol 2012; 65:871-82. [PMID: 22929217 PMCID: PMC4425404 DOI: 10.1016/j.ympev.2012.08.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 08/11/2012] [Accepted: 08/13/2012] [Indexed: 01/16/2023]
Abstract
Evolutionary relationships among placental mammalian orders have been controversial. Whole genome sequencing and new computational methods offer opportunities to resolve the relationships among 10 genomes belonging to the mammalian orders Primates, Rodentia, Carnivora, Perissodactyla and Artiodactyla. By application of the double cut and join distance metric, where gene order is the phylogenetic character, we computed genomic distances among the sampled mammalian genomes. With a marsupial outgroup, the gene order tree supported a topology in which Rodentia fell outside the cluster of Primates, Carnivora, Perissodactyla, and Artiodactyla. Results of breakpoint reuse rate and synteny block length analyses were consistent with the prediction of random breakage model, which provided a diagnostic test to support use of gene order as an appropriate phylogenetic character in this study. We discussed the influence of rate differences among lineages and other factors that may contribute to different resolutions of mammalian ordinal relationships by different methods of phylogenetic reconstruction.
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Affiliation(s)
- Haiwei Luo
- Department of Biological Sciences, University of South Carolina, Columbia 29208, USA
| | - William Arndt
- Department of Computer Science and Engineering, University of South Carolina, Columbia 29208, USA
| | - Yiwei Zhang
- Department of Computer Science and Engineering, University of South Carolina, Columbia 29208, USA
| | - Guanqun Shi
- Department of Computer Science, University of California, Riverside, 92521, USA
| | - Max Alekseyev
- Department of Computer Science and Engineering, University of South Carolina, Columbia 29208, USA
| | - Jijun Tang
- Department of Computer Science and Engineering, University of South Carolina, Columbia 29208, USA
| | - Austin L. Hughes
- Department of Biological Sciences, University of South Carolina, Columbia 29208, USA
| | - Robert Friedman
- Department of Biological Sciences, University of South Carolina, Columbia 29208, USA
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36
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Zoller S, Schneider A. Improving phylogenetic inference with a semiempirical amino acid substitution model. Mol Biol Evol 2012; 30:469-79. [PMID: 23002090 DOI: 10.1093/molbev/mss229] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Amino acid substitution matrices describe the rates by which amino acids are replaced during evolution. In contrast to nucleotide or codon models, amino acid substitution matrices are in general parameterless and empirically estimated, probably because there is no obvious parametrization for amino acid substitutions. Principal component analysis has previously been used to improve codon substitution models by empirically finding the most relevant parameters. Here, we apply the same method to amino acid substitution matrices, leading to a semiempirical substitution model that can adjust the transition rates to the protein sequences under investigation. Our new model almost invariably achieves the best likelihood values in large-scale comparisons with established amino acid substitution models (JTT, WAG, and LG). In particular for longer alignments, these likelihood gains are considerably larger than what could be expected from simply having more parameters. The application of our model differs from that of mixture models (such as UL2 or UL3), as we optimize one rate matrix per alignment, whereas mixture models apply the variation per alignments site. This makes our model computationally more efficient, while the performance is comparable to that of UL3. Applied to the phylogenetic problem of the origin of placental mammals, our new model and the UL3 mixed model are the only ones of the tested models that cluster Afrotheria and Xenarthra into a clade called Atlantogenata, which would be in correspondence with recent findings using more sophisticated phylogenetic methods.
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Affiliation(s)
- Stefan Zoller
- Computational Biochemistry Research Group, ETH Zürich, Zürich, Switzerland.
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37
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Resolution of the laurasiatherian phylogeny: Evidence from genomic data. Mol Phylogenet Evol 2012; 64:685-9. [DOI: 10.1016/j.ympev.2012.04.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 04/03/2012] [Accepted: 04/17/2012] [Indexed: 11/17/2022]
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Resolving conflict in eutherian mammal phylogeny using phylogenomics and the multispecies coalescent model. Proc Natl Acad Sci U S A 2012; 109:14942-7. [PMID: 22930817 DOI: 10.1073/pnas.1211733109] [Citation(s) in RCA: 307] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The reconstruction of the Tree of Life has relied almost entirely on concatenation methods, which do not accommodate gene tree heterogeneity, a property that simulations and theory have identified as a likely cause of incongruent phylogenies. However, this incongruence has not yet been demonstrated in empirical studies. Several key relationships among eutherian mammals remain controversial and conflicting among previous studies, including the root of eutherian tree and the relationships within Euarchontoglires and Laurasiatheria. Both bayesian and maximum-likelihood analysis of genome-wide data of 447 nuclear genes from 37 species show that concatenation methods indeed yield strong incongruence in the phylogeny of eutherian mammals, as revealed by subsampling analyses of loci and taxa, which produced strongly conflicting topologies. In contrast, the coalescent methods, which accommodate gene tree heterogeneity, yield a phylogeny that is robust to variable gene and taxon sampling and is congruent with geographic data. The data also demonstrate that incomplete lineage sorting, a major source of gene tree heterogeneity, is relevant to deep-level phylogenies, such as those among eutherian mammals. Our results firmly place the eutherian root between Atlantogenata and Boreoeutheria and support ungulate polyphyly and a sister-group relationship between Scandentia and Primates. This study demonstrates that the incongruence introduced by concatenation methods is a major cause of long-standing uncertainty in the phylogeny of eutherian mammals, and the same may apply to other clades. Our analyses suggest that such incongruence can be resolved using phylogenomic data and coalescent methods that deal explicitly with gene tree heterogeneity.
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Svartman M, Stanyon R. The chromosomes of Afrotheria and their bearing on mammalian genome evolution. Cytogenet Genome Res 2012; 137:144-53. [PMID: 22868637 DOI: 10.1159/000341387] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Afrotheria is the clade of placental mammals that, together with Xenarthra, Euarchontoglires and Laurasiatheria, represents 1 of the 4 main recognized supraordinal eutherian clades. It reunites 6 orders of African origin: Proboscidea, Sirenia, Hyracoidea, Macroscelidea, Afrosoricida and Tubulidentata. The apparently unlikely relationship among such disparate morphological taxa and their possible basal position at the base of the eutherian phylogenetic tree led to a great deal of attention and research on the group. The use of biomolecular data was pivotal in Afrotheria studies, as they were the basis for the recognition of this clade. Although morphological evidence is still scarce, a plethora of molecular data firmly attests to the phylogenetic relationship among these mammals of African origin. Modern cytogenetic techniques also gave a significant contribution to the study of Afrotheria, revealing chromosome signatures for the group as a whole, as well as for some of its internal relationships. The associations of human chromosomes HSA1/19 and 5/21 were found to be chromosome signatures for the group and provided further support for Afrotheria. Additional chromosome synapomorphies were also identified linking elephants and manatees in Tethytheria (the associations HSA2/3, 3/13, 8/22, 18/19 and the lack of HSA4/8) and elephant shrews with the aardvark (HSA2/8, 3/20 and 10/17). Herein, we review the current knowledge on Afrotheria chromosomes and genome evolution. The already available data on the group suggests that further work on this apparently bizarre assemblage of mammals will provide important data to a better understanding on mammalian genome evolution.
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Affiliation(s)
- M Svartman
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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Svartman M. Chromosome evolution in Xenarthra: new insights from an ancient group. Cytogenet Genome Res 2012; 137:130-43. [PMID: 22678153 DOI: 10.1159/000339115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The Magnaorder Xenarthra is one of the four main supraordinal eutherian clades, together with Afrotheria, Euarchontoglires and Laurasiatheria. Xenarthra is an eminently Central and South American group of special interest in phylogenetic studies due to its possible position at the base of the eutherian tree. The use of modern cytogenetic techniques in some species of Xenarthra has provided important insights into the karyotypic evolution of mammals. Nevertheless, chromosome analyses in the group are still restricted, with only a few individuals of each species studied and karyotype descriptions mostly without banding patterns. In addition, it is likely that still unknown species exist and that the chromosome variability in the group is underestimated. We present a review of the currently available data on Xenarthra chromosomes and genomes and on the impact that their study has had in the understanding of mammalian genome evolution. It is clear that further cytogenetic analyses in Xenarthra, including banding patterns and molecular approaches, are likely to help in the identification of new species, reveal still undetected chromosome variations, provide information to support conservation strategies planning, and greatly contribute to a better understanding of mammalian genome evolution.
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Affiliation(s)
- M Svartman
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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Azevedo NF, Svartman M, Manchester A, de Moraes-Barros N, Stanyon R, Vianna-Morgante AM. Chromosome painting in three-toed sloths: a cytogenetic signature and ancestral karyotype for Xenarthra. BMC Evol Biol 2012; 12:36. [PMID: 22429690 PMCID: PMC3383463 DOI: 10.1186/1471-2148-12-36] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 03/19/2012] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Xenarthra (sloths, armadillos and anteaters) represent one of four currently recognized Eutherian mammal supraorders. Some phylogenomic studies point to the possibility of Xenarthra being at the base of the Eutherian tree, together or not with the supraorder Afrotheria. We performed painting with human autosomes and X-chromosome specific probes on metaphases of two three-toed sloths: Bradypus torquatus and B. variegatus. These species represent the fourth of the five extant Xenarthra families to be studied with this approach. RESULTS Eleven human chromosomes were conserved as one block in both B. torquatus and B. variegatus: (HSA 5, 6, 9, 11, 13, 14, 15, 17, 18, 20, 21 and the X chromosome). B. torquatus, three additional human chromosomes were conserved intact (HSA 1, 3 and 4). The remaining human chromosomes were represented by two or three segments on each sloth. Seven associations between human chromosomes were detected in the karyotypes of both B. torquatus and B. variegatus: HSA 3/21, 4/8, 7/10, 7/16, 12/22, 14/15 and 17/19. The ancestral Eutherian association 16/19 was not detected in the Bradypus species. CONCLUSIONS Our results together with previous reports enabled us to propose a hypothetical ancestral Xenarthran karyotype with 48 chromosomes that would differ from the proposed ancestral Eutherian karyotype by the presence of the association HSA 7/10 and by the split of HSA 8 into three blocks, instead of the two found in the Eutherian ancestor. These same chromosome features point to the monophyly of Xenarthra, making this the second supraorder of placental mammals to have a chromosome signature supporting its monophyly.
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Affiliation(s)
- Nathália F Azevedo
- Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, Cidade Universitária, São Paulo, Brazil
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Gravett N, Bhagwandin A, Lyamin OI, Siegel JM, Manger PR. Sleep in the rock hyrax, Procavia capensis. BRAIN, BEHAVIOR AND EVOLUTION 2012; 79:155-69. [PMID: 22301688 DOI: 10.1159/000335342] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 05/13/2011] [Indexed: 11/19/2022]
Abstract
We investigated sleep in therock hyrax, Procavia capensis, a social mammal that typically lives in colonies on rocky outcrops throughout most parts of Southern Africa. The sleep of 5 wild-captured, adult rock hyraxes was recorded continuously for 72 h using telemetric relay of signals and allowing unimpeded movement. In addition to waking, slow wave sleep (SWS) and an unambiguous rapid eye movement (REM) state, a sleep state termed somnus innominatus (SI), characterized by low-voltage, high-frequency electroencephalogram, an electromyogram that stayed at the same amplitude as the preceding SWS episode and a mostly regular heart rate, were identified. If SI can be considered a form of low-voltage non-REM, the implication would be that the rock hyrax exhibits the lowest amount of REM recorded for any terrestrial mammal studied to date. Conversely, if SI is a form of REM sleep, it would lead to the classification of a novel subdivision of this state; however, further investigation would be required. The hyraxes spent on average 15.89 h (66.2%) of the time awake, 6.02 h (25.1%) in SWS, 43 min (3%) in SI and 6 min (0.4%) in REM. The unambiguous REM sleep amounts were on average less than 6 min/day. The most common state transition pathway in these animals was found to be wake → SWS → wake. No significant differences were noted with regard to total sleep time, number of episodes and episode duration for all states between the light and dark periods.Thus, prior classification of the rock hyrax as strongly diurnal does not appear to hold under controlled laboratory conditions.
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Affiliation(s)
- Nadine Gravett
- School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Hautier L, Stansfield FJ, Allen WRT, Asher RJ. Skeletal development in the African elephant and ossification timing in placental mammals. Proc Biol Sci 2012; 279:2188-95. [PMID: 22298853 DOI: 10.1098/rspb.2011.2481] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We provide here unique data on elephant skeletal ontogeny. We focus on the sequence of cranial and post-cranial ossification events during growth in the African elephant (Loxodonta africana). Previous analyses on ossification sequences in mammals have focused on monotremes, marsupials, boreoeutherian and xenarthran placentals. Here, we add data on ossification sequences in an afrotherian. We use two different methods to quantify sequence heterochrony: the sequence method and event-paring/Parsimov. Compared with other placentals, elephants show late ossifications of the basicranium, manual and pedal phalanges, and early ossifications of the ischium and metacarpals. Moreover, ossification in elephants starts very early and progresses rapidly. Specifically, the elephant exhibits the same percentage of bones showing an ossification centre at the end of the first third of its gestation period as the mouse and hamster have close to birth. Elephants show a number of features of their ossification patterns that differ from those of other placental mammals. The pattern of the initiation of the ossification evident in the African elephant underscores a possible correlation between the timing of ossification onset and gestation time throughout mammals.
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Affiliation(s)
- Lionel Hautier
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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Rothfels CJ, Larsson A, Kuo LY, Korall P, Chiou WL, Pryer KM. Overcoming Deep Roots, Fast Rates, and Short Internodes to Resolve the Ancient Rapid Radiation of Eupolypod II Ferns. Syst Biol 2012; 61:490-509. [DOI: 10.1093/sysbio/sys001] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Carl J. Rothfels
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Anders Larsson
- Systematic Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Li-Yaung Kuo
- Institute of Ecology and Evolutionary Biology, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Petra Korall
- Systematic Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Wen-Liang Chiou
- Botanical Garden Division, Taiwan Forestry Research Institute, 53 Nan-hai Road, Taipei 10066, Taiwan
| | - Kathleen M. Pryer
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
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McCormack JE, Faircloth BC, Crawford NG, Gowaty PA, Brumfield RT, Glenn TC. Ultraconserved elements are novel phylogenomic markers that resolve placental mammal phylogeny when combined with species-tree analysis. Genome Res 2011; 22:746-54. [PMID: 22207614 DOI: 10.1101/gr.125864.111] [Citation(s) in RCA: 260] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Phylogenomics offers the potential to fully resolve the Tree of Life, but increasing genomic coverage also reveals conflicting evolutionary histories among genes, demanding new analytical strategies for elucidating a single history of life. Here, we outline a phylogenomic approach using a novel class of phylogenetic markers derived from ultraconserved elements and flanking DNA. Using species-tree analysis that accounts for discord among hundreds of independent loci, we show that this class of marker is useful for recovering deep-level phylogeny in placental mammals. In broad outline, our phylogeny agrees with recent phylogenomic studies of mammals, including several formerly controversial relationships. Our results also inform two outstanding questions in placental mammal phylogeny involving rapid speciation, where species-tree methods are particularly needed. Contrary to most phylogenomic studies, our study supports a first-diverging placental mammal lineage that includes elephants and tenrecs (Afrotheria). The level of conflict among gene histories is consistent with this basal divergence occurring in or near a phylogenetic "anomaly zone" where a failure to account for coalescent stochasticity will mislead phylogenetic inference. Addressing a long-standing phylogenetic mystery, we find some support from a high genomic coverage data set for a traditional placement of bats (Chiroptera) sister to a clade containing Perissodactyla, Cetartiodactyla, and Carnivora, and not nested within the latter clade, as has been suggested recently, although other results were conflicting. One of the most remarkable findings of our study is that ultraconserved elements and their flanking DNA are a rich source of phylogenetic information with strong potential for application across Amniotes.
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Affiliation(s)
- John E McCormack
- Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
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Ciancio MR, Castro MC, Galliari FC, Carlini AA, Asher RJ. Evolutionary Implications of Dental Eruption in Dasypus (Xenarthra). J MAMM EVOL 2011. [DOI: 10.1007/s10914-011-9177-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Kuraku S, Kuratani S. Genome-wide detection of gene extinction in early mammalian evolution. Genome Biol Evol 2011; 3:1449-62. [PMID: 22094861 PMCID: PMC3296468 DOI: 10.1093/gbe/evr120] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Detecting gene losses is a novel aspect of evolutionary genomics that has been made feasible by whole-genome sequencing. However, research to date has concentrated on elucidating evolutionary patterns of genomic components shared between species, rather than identifying disparities between genomes. In this study, we searched for gene losses in the lineage leading to eutherian mammals. First, as a pilot analysis, we selected five gene families (Wnt, Fgf, Tbx, TGFβ, and Frizzled) for molecular phylogenetic analyses, and identified mammalian lineage-specific losses of Wnt11b, Tbx6L/VegT/tbx16, Nodal-related, ADMP1, ADMP2, Sizzled, and Crescent. Second, automated genome-wide phylogenetic screening was implemented based on this pilot analysis. As a result, we detected 147 chicken genes without eutherian orthologs, which resulted from 141 gene loss events. Our inventory contained a group of regulatory genes governing early embryonic axis formation, such as Noggins, and multiple members of the opsin and prolactin-releasing hormone receptor (“PRLHR”) gene families. Our findings highlight the potential of genome-wide gene phylogeny (“phylome”) analysis in detecting possible rearrangement of gene networks and the importance of identifying losses of ancestral genomic components in analyzing the molecular basis underlying phenotypic evolution.
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Affiliation(s)
- Shigehiro Kuraku
- Laboratory for Evolutionary Morphology, RIKEN Center for Developmental Biology, Kobe, Japan.
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Genomic data reject the hypothesis of a prosimian primate clade. J Hum Evol 2011; 61:295-305. [DOI: 10.1016/j.jhevol.2011.04.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 04/04/2011] [Accepted: 04/05/2011] [Indexed: 01/06/2023]
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Gunbin KV, Suslov VV, Turnaev II, Afonnikov DA, Kolchanov NA. Molecular evolution of cyclin proteins in animals and fungi. BMC Evol Biol 2011; 11:224. [PMID: 21798004 PMCID: PMC3162929 DOI: 10.1186/1471-2148-11-224] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 07/28/2011] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND The passage through the cell cycle is controlled by complexes of cyclins, the regulatory units, with cyclin-dependent kinases, the catalytic units. It is also known that cyclins form several families, which differ considerably in primary structure from one eukaryotic organism to another. Despite these lines of evidence, the relationship between the evolution of cyclins and their function is an open issue. Here we present the results of our study on the molecular evolution of A-, B-, D-, E-type cyclin proteins in animals and fungi. RESULTS We constructed phylogenetic trees for these proteins, their ancestral sequences and analyzed patterns of amino acid replacements. The analysis of infrequently fixed atypical amino acid replacements in cyclins evidenced that accelerated evolution proceeded predominantly during paralog duplication or after it in animals and fungi and that it was related to aromorphic changes in animals. It was shown also that evolutionary flexibility of cyclin function may be provided by consequential reorganization of regions on protein surface remote from CDK binding sites in animal and fungal cyclins and by functional differentiation of paralogous cyclins formed in animal evolution. CONCLUSIONS The results suggested that changes in the number and/or nature of cyclin-binding proteins may underlie the evolutionary role of the alterations in the molecular structure of cyclins and their involvement in diverse molecular-genetic events.
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Affiliation(s)
- Konstantin V Gunbin
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
| | - Valentin V Suslov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
| | - Igor I Turnaev
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
| | - Dmitry A Afonnikov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
- Novosibirsk state University, Pirogova, 2, Novosibirsk, Russia
| | - Nikolay A Kolchanov
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave., 10, Novosibirsk, Russia
- Novosibirsk state University, Pirogova, 2, Novosibirsk, Russia
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Billet G, Martin T. No evidence for an afrotherian-like delayed dental eruption in South American notoungulates. Naturwissenschaften 2011; 98:509-17. [DOI: 10.1007/s00114-011-0795-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Revised: 03/29/2011] [Accepted: 04/01/2011] [Indexed: 10/18/2022]
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