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Welcome
Fri, 09/23/2011 - 08:54
We focus on comparative analyses of genome sequences to understand principles of molecular evolution and approach the fundamental questions of the origin and evolution of biological complexity. Through analysis of multiple species, we aim to quantify evolutionary processes that shape repertoires of functional genomic elements such as - protein coding genes
- non-coding RNA genes (e.g. microRNAs), and
- conserved non-genic sequences (CNS)
as well as to interrogate and predict their functions, analysing sequence variability patterns among different species and within populations. Prioritising medical and evolutionary questions, we are focusing on two strategic directions of vertebrate and insect genomics, where we are participating in international collaborative projects to analyze new genomes and collaborating with experimental functional genomics laboratories.
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Comparative genomics of Anopheles malaria mosquitoes: dynamic genomic changes over 100 million years and extensive gene flow amongst closely-related species
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Anopheles mosquitoes are responsible for transmitting human malaria parasites that cause an estimated 200 million cases and more than 600 thousand deaths each year. However, of the almost 500 different Anopheles species, only a few dozen can carry the parasite and only a handful of species are responsible for the vast majority of transmissions. To investigate the genetic differences between the deadly parasite-transmitting species and their harmless (but still annoying) cousins, an international team of scientists, including researchers from the University of Geneva and the SIB Swiss Institute of Bioinformatics, sequenced the genomes of sixteen Anopheles species from around the globe. Two articles published on November 27th in the journal Science describe detailed genomic comparisons of these mosquitoes and the deadliest of them all, Anopheles gambiae. These results offer new insights into how these species are related to each other and how the dynamic evolution of their genomes may contribute to their flexibility to adapt to new environments and to seek out human blood. These newly-sequenced genomes represent a substantial contribution to the scientific resources that will advance our understanding of the diverse biological characteristics of mosquitoes, and help to eliminate diseases that have a major impact on global public health. Read More
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Selected recent publications
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OrthoDB v8: update of the hierarchical catalog of orthologs and the underlying free softwareKriventseva EV, Tegenfeldt F, Petty TJ, Waterhouse RM, Simão FA, Pozdnyakov IA, Ioannidis P, Zdobnov EM. Nucleic Acids Res. PMID: 25428351 Orthology, refining the concept of homology, is the cornerstone of evolutionary comparative studies. With the ever-increasing availability of genomic data, inference of orthology has become instrumental for generating hypotheses about gene functions crucial to many studies. This update of the OrthoDB hierarchical catalog of orthologs (http://www.orthodb.org) covers 3027 complete genomes, including the most comprehensive set of 87 arthropods, 61 vertebrates, 227 fungi and 2627 bacteria (sampling the most complete and representative genomes from over 11,000 available). In addition to the most extensive integration of functional annotations from UniProt, InterPro, GO, OMIM, model organism phenotypes and COG functional categories, OrthoDB uniquely provides evolutionary annotations including rates of ortholog sequence divergence, copy-number profiles, sibling groups and gene architectures. We re-designed the entirety of the OrthoDB website from the underlying technology to the user interface, enabling the user to specify species of interest and to select the relevant orthology level by the NCBI taxonomy. The text searches allow use of complex logic with various identifiers of genes, proteins, domains, ontologies or annotation keywords and phrases. Gene copy-number profiles can also be queried. This release comes with the freely available underlying ortholog clustering pipeline (http://www.orthodb.org/software).
Extensive introgression in a malaria vector species complex revealed by phylogenomicsFontaine MC, Pease JB, Steele A, Waterhouse RM, Neafsey DE, Sharakhov IV, Jiang X, Hall AB, Catteruccia F, Kakani E, Mitchell SN, Wu YC, Smith HA, Love RR, Lawniczak MK, Slotman MA, Emrich SJ, Hahn MW, Besansky NJ. Science PMID: 25431491 Introgressive hybridization is now recognized as a widespread phenomenon, but its role in evolution remains contested. Here we use newly available reference genome assemblies to investigate phylogenetic relationships and introgression in a medically important group of Afrotropical mosquito sibling species. We have identified the correct species branching order to resolve a contentious phylogeny, and show that lineages leading to the principal vectors of human malaria were among the first to split. Pervasive autosomal introgression between these malaria vectors means that only a small fraction of the genome, mainly on the X chromosome, has not crossed species boundaries. Our results suggest that traits enhancing vectorial capacity may be gained through interspecific gene flow, including between non-sister species.
Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoesNeafsey DE, Waterhouse RM, Abai MR, Aganezov SS, Alekseyev MA, Allen JE, Amon J, Arcà B, Arensburger P, Artemov G, Assour LA, Basseri H, Berlin A, Birren BW, Blandin SA, Brockman AI, Burkot TR, Burt A, Chan CS, Chauve C, Chiu JC, Christensen M, Costantini C, Davidson VL, Deligianni E, Dottorini T, Dritsou V, Gabriel SB, Guelbeogo WM, Hall AB, Han MV, Hlaing T, Hughes DS, Jenkins AM, Jiang X, Jungreis I, Kakani EG, Kamali M, Kemppainen P, Kennedy RC, Kirmitzoglou IK, Koekemoer LL, Laban N, Langridge N, Lawniczak MK, Lirakis M, Lobo NF, Lowy E, MacCallum RM, Mao C, Maslen G, Mbogo C, McCarthy J, Michel K, Mitchell SN, Moore W, Murphy KA, Naumenko AN, Nolan T, Novoa EM, O'Loughlin S, Oringanje C, Oshaghi MA, Pakpour N, Papathanos PA, Peery AN, Povelones M, Prakash A, Price DP, Rajaraman A, Reimer LJ, Rinker DC, Rokas A, Russell TL, Sagnon N, Sharakhova MV, Shea T, Simão FA, Simard F, Slotman MA, Somboon P, Stegniy V, Struchiner CJ, Thomas GW, Tojo M, Topalis P, Tubio JM, Unger MF, Vontas J, Walton C, Wilding CS, Willis JH, Wu YC, Yan G, Zdobnov EM, Zhou X, Catteruccia F, Christophides GK, Collins FH, Cornman RS, Crisanti A, Donnelly MJ, Emrich SJ, Fontaine MC, Gelbart W, Hahn MW, Hansen IA, Howell PI, Kafatos FC, Kellis M, Lawson D, Louis C, Luckhart S, Muskavitch MA, Ribeiro JM, Riehle MA, Sharakhov IV, Tu Z, Zwiebel LJ, Besansky NJ. Science PMID: 25554792 Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover, but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts.
Social insect genomes: dramatic evolution in gene composition & regulation, preserving regulatory features linked to socialitySimola DF, Wissler L, Donahue G, Waterhouse RM, Helmkampf M, Roux J, Nygaard S, Glastad K, Hagen DE, Viljakainen L, Reese JT, Hunt BG, Graur D, Elhaik E, Kriventseva E, Wen J, Parker BJ, Cash E, Privman E, Childers CP, Munos-Torres MC, Boomsma JJ, Bornberg-Bauer E, Currie C, Elsik CG, Suen G, Goodisman MA, Keller L, Liebig J, Rawls A, Reinberg D, Smith CD, Smith CR, Tsutsui N, Wurm Y, Zdobnov EM, Berger SL, Gadau J. Genome Research PMID: 23636946 Genomes of eusocial insects code for dramatic examples of phenotypic plasticity and social organization. We compared the genomes of seven ants, the honeybee, and various solitary insects to examine whether eusocial lineages share distinct features of genomic organization. Each ant lineage contains ~4,000 novel genes, but only 64 of these genes are conserved among all seven ants. Many gene families have been expanded in ants, notably those involved in chemical communication (e.g., desaturases and odorant receptors). Alignment of the ant genomes revealed reduced purifying selection compared to Drosophila without significantly reduced synteny. Correspondingly, ant genomes exhibit dramatic divergence of non-coding regulatory elements, however extant conserved regions are enriched for novel non-coding RNAs and transcription factor binding sites. Comparison of orthologous gene promoters between eusocial and solitary species revealed significant regulatory evolution in both cis (e.g., CREB) and trans (e.g., Forkhead) for nearly 2000 genes, many of which exhibit phenotypic plasticity. Our results emphasize that genomic changes can occur remarkably fast in ants, as two recently diverged leaf-cutter ant species exhibit faster accumulation of species-specific genes and greater divergence in regulatory elements compared to other ants or Drosophila. Thus, while the "socio-genomes" of ants and the honeybee are broadly characterized by a pervasive pattern of divergence in gene composition and regulation, they preserve lineage-specific regulatory features linked to eusociality. We propose that changes in gene regulation played a key role in the origins of insect eusociality, whereas changes in gene composition were more relevant for lineage-specific eusocial adaptations.
Identification of Site-Specific Adaptations Conferring Increased Neural Cell Tropism during Human Enterovirus 71 Infection.Cordey S, Petty TJ, Schibler M, Martinez Y, Gerlach D, van Belle S, Turin L, Zdobnov EM, Kaiser L, Tapparel C. PLoS Pathog PMID: 22910880 Enterovirus 71 (EV71) is one of the most virulent enteroviruses, but the specific molecular features that enhance its ability to disseminate in humans remain unknown. We analyzed the genomic features of EV71 in an immunocompromised host with disseminated disease according to the different sites of infection. Comparison of five full-length genomes sequenced directly from respiratory, gastrointestinal, nervous system, and blood specimens revealed three nucleotide changes that occurred within a five-day period: a non-conservative amino acid change in VP1 located within the BC loop (L97R), a region considered as an immunogenic site and possibly important in poliovirus host adaptation; a conservative amino acid substitution in protein 2B (A38V); and a silent mutation in protein 3D (L175). Infectious clones were constructed using both BrCr (lineage A) and the clinical strain (lineage C) backgrounds containing either one or both non-synonymous mutations. In vitro cell tropism and competition assays revealed that the VP1(97) Leu to Arg substitution within the BC loop conferred a replicative advantage in SH-SY5Y cells of neuroblastoma origin. Interestingly, this mutation was frequently associated in vitro with a second non-conservative mutation (E167G or E167A) in the VP1 EF loop in neuroblastoma cells. Comparative models of these EV71 VP1 variants were built to determine how the substitutions might affect VP1 structure and/or interactions with host cells and suggest that, while no significant structural changes were observed, the substitutions may alter interactions with host cell receptors. Taken together, our results show that the VP1 BC loop region of EV71 plays a critical role in cell tropism independent of EV71 lineage and, thus, may have contributed to dissemination and neurotropism in the immunocompromised patient.
The ecoresponsive genome of Daphnia pulexColbourne JK, Pfrender ME, Gilbert D, Thomas WK, Tucker A, Oakley TH, Tokishita S, Aerts A, Arnold GJ, Basu MK, Bauer DJ, Cáceres CE, Carmel L, Casola C, Choi JH, Detter JC, Dong Q, Dusheyko S, Eads BD, Fröhlich T, Geiler-Samerotte KA, Gerlach D, Hatcher P, Jogdeo S, Krijgsveld J, Kriventseva EV, Kültz D, Laforsch C, Lindquist E, Lopez J, Manak JR, Muller J, Pangilinan J, Patwardhan RP, Pitluck S, Pritham EJ, Rechtsteiner A, Rho M, Rogozin IB, Sakarya O, Salamov A, Schaack S, Shapiro H, Shiga Y, Skalitzky C, Smith Z, Souvorov A, Sung W, Tang Z, Tsuchiya D, Tu H, Vos H, Wang M, Wolf YI, Yamagata H, Yamada T, Ye Y, Shaw JR, Andrews J, Crease TJ, Tang H, Lucas SM, Robertson HM, Bork P, Koonin EV, Zdobnov EM, Grigoriev IV, Lynch M, Boore JL. Science PMID: 21292972 We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. More than a third of Daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challenges.
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