Genoma: quem precisa de arquitetura?

sexta-feira, novembro 19, 2010

By Megan Scudellari

Who needs structure, anyway?

A tiny, mucus-covered animal shatters assumptions about genome architecture

[Published 18th November 2010 07:00 PM GMT]

The architecture features of the animal genome may not be as valuable as scientists once thought. 

The newly described genome of a tiny, transparent marine animal breaks all the structural rules previously thought to be important for animal genomes -- overturning the belief that common architectural features of genomes, observed across all animal kingdoms, are maintained by natural selection.

The finding, published online today at Science, shows that an animal genome can be highly flexible and still maintain its function. 

"Given the large number of genomes that have been nearly completely sequenced over the past ten years, one would expect us to have reached near saturation with respect to new findings, but surprises still emerge," Michael Lynch, a researcher studying evolution and genomics at Indiana University who was not involved in the research, said in an email to The Scientist. 

Scientists have observed remarkable similarities in genome organization between species as distant as humans and sea sponges. These common genome elements -- including the order of genes, the organization of introns and exons, and the repertoire of developmental genes -- has led many to infer that animal genome architecture is essential to preserve function and is actively maintained by natural selection. 

The genome of a tunicate, Oikopleura dioica -- a small, rapidly evolving underwater filter feeder abundant in plankton -- shatters those preconceptions. 

"The paper is outstanding in the sense that it revealed several peculiarities that will certainly shed light on the evolution of life in this planet," said Sandro Jose de Souza, a biologist at the Ludwig Institute for Cancer Research in Brazil who was not involved in the research, in an email.

Read more here/Leia mais aqui: The Scientist


Published Online 18 November 2010
Science DOI: 10.1126/science.1194167


Plasticity of Animal Genome Architecture Unmasked by Rapid Evolution of a Pelagic Tunicate

France Denoeud1,2,3, Simon Henriet4, Sutada Mungpakdee4,*, Jean-Marc Aury1,2,3,*, Corinne Da Silva1,2,3,*, Henner Brinkmann5, Jana Mikhaleva4, Lisbeth Charlotte Olsen4, Claire Jubin1,2,3, Cristian Cañestro6, Jean-Marie Bouquet4, Gemma Danks4,7, Julie Poulain1,2,3, Coen Campsteijn4, Marcin Adamski4, Ismael Cross8, Fekadu Yadetie4, Matthieu Muffato9, Alexandra Louis9, Stephen Butcher10, Georgia Tsagkogeorga11, Anke Konrad22, Sarabdeep Singh12, Marit Flo Jensen4, Evelyne Huynh Cong4, Helen Eikeseth-Otteraa4, Benjamin Noel1,2,3, Véronique Anthouard1,2,3, Betina M. Porcel1,2,3, Rym Kachouri-Lafond13, Atsuo Nishino14, Matteo Ugolini4, Pascal Chourrout15, Hiroki Nishida14, Rein Aasland16, Snehalata Huzurbazar12, Eric Westhof13, Frédéric Delsuc11, Hans Lehrach17, Richard Reinhardt17, Jean Weissenbach1,2,3, Scott W. Roy18, François Artiguenave1,2,3, John H. Postlethwait6, J. Robert Manak10, Eric M. Thompson4,19, Olivier Jaillon1,2,3, Louis Du Pasquier20, Pierre Boudinot21, David A. Liberles22, Jean-Nicolas Volff23, Hervé Philippe5, Boris Lenhard4,7, Hugues Roest Crollius9, Patrick Wincker1,2,3,† and Daniel Chourrout4,†

+Author Affiliations

1CEA, IG, Genoscope, Evry, France.
2CNRS, UMR 8030, Evry, France.
3Université d’Evry, Evry, France.
4Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway.
5Département de Biochimie, Université de Montréal, Montréal, Canada.
6Institute of Neuroscience, University of Oregon, Eugene, OR, USA.
7Bergen Center for Computational Science, University of Bergen, Bergen, Norway.
8Laboratorio de Genética, Universidad de Cádiz, Cádiz, Spain.
9Dyogen Lab, CNRS UMR 8541, Ecole Normale Supérieure, Paris, France.
10Department of Biology, University of Iowa, Iowa City, IA, USA.
11Laboratoire de Paléontologie, Phylogénie et Paléobiologie, Institut des Sciences de l’Evolution, UMR 5554-CNRS, Université Montpellier II, Montpellier, France.
12Department of Statistics, University of Wyoming, Laramie, WY, USA.
13Institut de Biologie Cellulaire et Moléculaire du CNRS, Université de Strasbourg, Strasbourg, France.
14Department of Biological Sciences, Osaka University, Osaka, Japan.
15Centre Hospitalier d’Albi, Albi, France.
16Department of Molecular Biology, University of Bergen, Bergen, Norway.
17Vertebrate Genomics, Max Planck Institute for Molecular Genetics, Berlin, Germany.
18National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA.
19Department of Biology, University of Bergen, Bergen, Norway.
20Institute of Zoology and Evolutionary Biology, University of Basel, Basel, Switzerland.
21INRA, Virologie et Immunologie Moléculaires, Jouy-en-Josas, France.
22Department of Molecular Biology, University of Wyoming, Laramie, WY, USA.
23Institut de Génomique Fonctionnelle de Lyon, UMR 5242 CNRS/INRA/UCBL/ENS, Ecole Normale Supérieure de Lyon, Lyon, France.
†To whom correspondence should be addressed. E-mail: (D.C.); (P.W.)

↵* These authors contributed equally to this work.


Genomes of animals as different as sponge and human show conservation of global architecture. Here, we show that multiple genomic features including transposon diversity, developmental gene repertoire, physical gene order, and intron-exon organization are shattered in the tunicate Oikopleura, belonging to the sister group of vertebrates and retaining chordate morphology. Ancestral architecture of animal genomes can be deeply modified and may therefore be largely nonadaptive. This rapidly evolving animal lineage thus offers unique perspectives on the level of genome plasticity. It also illuminates issues as fundamental as the mechanisms of intron gain.

Received for publication 24 June 2010.
Accepted for publication 29 October 2010.


Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao site CAPES/Periódicos podem ler gratuitamente este artigo da Science e de mais 22.440 publicações científicas.



A expressão breaks all the structural rules previously thought to be important for animal genomes traduzida em graúdos: os dados encontrados nesta pesquisa refutam a hipótese de ancestralidade comum, mas isso não pode ser dito pois os agentes da KGB da Nomenklatura, ooops, os revisores por pares (peer-reviewers é très chic chérie, très chic) não permitiriam uma blasfêmia dessas contra Darwin, o homem que teve a maior ideia que toda a humanidade já teve: a evolução através da seleção natural. 

Todavia, a pesquisa deles mostra, no contexto de justificação teórica, que a seleção natural não é assim uma Brastemp de mecanismo evolucionário.

Lynch está correto: nós teremos mais surpresas com os genomas sendo decifrados. Quanto à declaração do Sandro, em que isso lança luz sobre a evolução? Só se for para lançar luz que os processos gradualistas darwinianos já entraram em colapso há muito tempo.

Fui, sem saber por que, mas o bom em ciência é que o que é verdade hoje pode se mostrar mentira amanhã. Ciência é que nem biruta de aeroporto: aonde soprar o vento das evidências, é para lá que a biruta, ooops, a ciência irá flanar. 

Mas, é a única forma de acesso mais confiável sobre a verdade da realidade das coisas e fenômenos naturais que temos. 

Humana, profundamente humana...