21 research outputs found
Improvement of the banana “Musa acuminata” reference sequence using NGS data and semi-automated bioinformatics methods
Recent advances in genomics indicate functional significance of a majority of genome sequences and their long range interactions. As a detailed examination of genome organization and function requires very high quality genome sequence, the objective of this study was to improve reference genome assembly of banana (Musa acuminata)
Law of Genome Evolution Direction : Coding Information Quantity Grows
The problem of the directionality of genome evolution is studied. Based on
the analysis of C-value paradox and the evolution of genome size we propose
that the function-coding information quantity of a genome always grows in the
course of evolution through sequence duplication, expansion of code, and gene
transfer from outside. The function-coding information quantity of a genome
consists of two parts, p-coding information quantity which encodes functional
protein and n-coding information quantity which encodes other functional
elements except amino acid sequence. The evidences on the evolutionary law
about the function-coding information quantity are listed. The needs of
function is the motive force for the expansion of coding information quantity
and the information quantity expansion is the way to make functional innovation
and extension for a species. So, the increase of coding information quantity of
a genome is a measure of the acquired new function and it determines the
directionality of genome evolution.Comment: 16 page
A global ocean atlas of eukaryotic genes
While our knowledge about the roles of microbes and viruses in the ocean has increased tremendously due to recent advances in genomics and metagenomics, research on marine microbial eukaryotes and zooplankton has benefited much less from these new technologies because of their larger genomes, their enormous diversity, and largely unexplored physiologies. Here, we use a metatranscriptomics approach to capture expressed genes in open ocean Tara Oceans stations across four organismal size fractions. The individual sequence reads cluster into 116 million unigenes representing the largest reference collection of eukaryotic transcripts from any single biome. The catalog is used to unveil functions expressed by eukaryotic marine plankton, and to assess their functional biogeography. Almost half of the sequences have no similarity with known proteins, and a great number belong to new gene families with a restricted distribution in the ocean. Overall, the resource provides the foundations for exploring the roles of marine eukaryotes in ocean ecology and biogeochemistry
Viral to metazoan marine plankton nucleotide sequences from the Tara Oceans expedition
A unique collection of oceanic samples was gathered by the Tara Oceans expeditions (2009-2013), targeting plankton organisms ranging from viruses to metazoans, and providing rich environmental context measurements. Thanks to recent advances in the field of genomics, extensive sequencing has been performed for a deep genomic analysis of this huge collection of samples. A strategy based on different approaches, such as metabarcoding, metagenomics, single-cell genomics and metatranscriptomics, has been chosen for analysis of size-fractionated plankton communities. Here, we provide detailed procedures applied for genomic data generation, from nucleic acids extraction to sequence production, and we describe registries of genomics datasets available at the European Nucleotide Archive (ENA, www.ebi.ac.uk/ena). The association of these metadata to the experimental procedures applied for their generation will help the scientific community to access these data and facilitate their analysis. This paper complements other efforts to provide a full description of experiments and open science resources generated from the Tara Oceans project, further extending their value for the study of the world's planktonic ecosystems
Functional repertoire convergence of distantly related eukaryotic plankton lineages abundant in the sunlit ocean
Marine planktonic eukaryotes play critical roles in global biogeochemical cycles and climate. However, their poor representation in culture collections limits our understanding of the evolutionary history and genomic underpinnings of planktonic ecosystems. Here, we used 280 billion Tara Oceans metagenomic reads from polar, temperate, and tropical sunlit oceans to reconstruct and manually curate more than 700 abundant and widespread eukaryotic environmental genomes ranging from 10 Mbp to 1.3 Gbp. This genomic resource covers a wide range of poorly characterized eukaryotic lineages that complement long-standing contributions from culture collections while better representing plankton in the upper layer of the oceans. We performed the first, to our knowledge, comprehensive genome-wide functional classification of abundant unicellular eukaryotic plankton, revealing four major groups connecting distantly related lineages. Neither trophic modes of plankton nor its vertical evolutionary history could completely explain the functional repertoire convergence of major eukaryotic lineages that coexisted within oceanic currents for millions of years
The <i>Ectocarpus</i> genome and the independent evolution of multicellularity in brown algae
Brown algae (Phaeophyceae) are complex photosynthetic organisms with a very different evolutionary history to green plants, to which they are only distantly related1. These seaweeds are the dominant species in rocky coastal ecosystems and they exhibit many interesting adaptations to these, often harsh, environments. Brown algae are also one of only a small number of eukaryotic lineages that have evolved complex multicellularity (Fig. 1).We report the 214 million base pair (Mbp) genome sequence of the filamentous seaweed Ectocarpus siliculosus (Dillwyn) Lyngbye, a model organism for brown algae, closely related to the kelps (Fig. 1). Genome features such as the presence of an extended set of light-harvesting and pigment biosynthesis genes and new metabolic processes such as halide metabolism help explain the ability of this organism to cope with the highly variable tidal environment. The evolution of multicellularity in this lineage is correlated with the presence of a rich array of signal transduction genes. Of particular interest is the presence of a family of receptor kinases, as the independent evolution of related molecules has been linked with the emergence of multicellularity in both the animal and green plant lineages. The Ectocarpus genome sequence represents an important step towards developing this organism as a model species, providing the possibility to combine genomic and genetic2 approaches to explore these and other aspects of brown algal biology further
Efeitos anestésicos da administração intranasal ou intramuscular de cetamina S+ e midazolam em pomba-rola (Streptotelia sp.)
A via intranasal é uma boa alternativa por ser indolor e de fácil aplicação em aves. O objetivo deste estudo foi avaliar os efeitos anestésicos da associação de cetamina S+ e midazolam pela via intranasal (IN) em comparação com a via intramuscular (IM) em pombos. Foram utilizados 12 pombos alocados em dois grupos com 15 dias de intervalo, os quais receberam: grupo IM: 20 mg/kg de cetamina S+ associada a 3,5 mg/kg de midazolam pela via intramuscular (musculatura do peito); e grupo IN, mesmo protocolo, porém, pela via intranasal. Os parâmetros avaliados foram: período de latência, tempo de duração em decúbito dorsal, tempo total de anestesia, tempo de recuperação e efeitos adversos. Para a análise estatística, empregou-se o teste de Wilcoxon, com as diferenças consideradas significativas quando P<0,05. O período de latência obtido foi de 30 [30-47,5] e 40 [30-50] segundos para IM e IN, respectivamente. O tempo de duração de decúbito dorsal foi de 59 [53,25-65] e 63 [37-71,25] minutos para IM e IN, respectivamente, sem diferenças significativas entre os grupos. Com relação à duração total de anestesia, foi observada diferença significativa, com 88 [86,25-94,5] e 68 [53,5-93] minutos para os grupos IM e IN, respectivamente. O tempo de recuperação foi mais curto no grupo IN (15 [4,25-19,5]) comparado ao IM (32 [28,25-38,25] minutos). Dois animais de cada grupo apresentaram regurgitação na fase de recuperação. Conclui-se que a administração de cetamina S+ e midazolam pela via intranasal é um método aceitável de administração de fármacos e produz anestesia rápida e eficaz em pombos
The origins and spread of domestic horses from the Western Eurasian steppes
Analysis of 273 ancient horse genomes reveals that modern domestic horses originated in the Western Eurasian steppes, especially the lower Volga-Don region.Domestication of horses fundamentally transformed long-range mobility and warfare(1). However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling(2-4) at Botai, Central Asia around 3500 bc(3). Other longstanding candidate regions for horse domestication, such as Iberia(5) and Anatolia(6), have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 bc, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association(7) between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 bc(8,9) driving the spread of Indo-European languages(10). This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium bc Sintashta culture(11,12).Descriptive and Comparative Linguistic
Pelagia noctiluca as a model to uncover scyphozoan developmental mechanisms.
International audienc
Gene loss and evolutionary rates following whole-genome duplication in teleost fishes.
Teleost fishes provide the first unambiguous support for ancient whole-genome duplication in an animal lineage. Studies in yeast or plants have shown that the effects of such duplications can be mediated by a complex pattern of gene retention and changes in evolutionary pressure. To explore such patterns in fishes, we have determined by phylogenetic analysis the evolutionary origin of 675 Tetraodon duplicated genes assigned to chromosomes, using additional data from other species of actinopterygian fishes. The subset of genes, which was retained in double after the genome duplication, is enriched in development, signaling, behavior, and regulation functional categories. The evolutionary rate of duplicate fish genes appears to be determined by 3 forces: 1) fish proteins evolve faster than mammalian orthologs; 2) the genes kept in double after genome duplication represent the subset under strongest purifying selection; and 3) following duplication, there is an asymmetric acceleration of evolutionary rate in one of the paralogs. These results show that similar mechanisms are at work in fishes as in yeast or plants and provide a framework for future investigation of the consequences of duplication in fishes and other animals