Marine invertebrates harbour a complex suite of bacterial and archaeal symbionts, a subset of which are probably linked to host health and homeostasis. Within a complex microbiome it can be difficult to tease apart beneficial or parasitic symbionts from nonessential commensal or transient microorganisms; however, one approach is to detect strong cophylogenetic patterns between microbial lineages and their respective hosts. We employed the Procrustean approach to cophylogeny (PACo) on 16S rRNA gene derived microbial community profiles paired with COI, 18S rRNA and ITS1 host phylogenies.
View Article and Find Full Text PDFMicrobiome assemblages of plants and animals often show a degree of correlation with host phylogeny; an eco-evolutionary pattern known as phylosymbiosis. Using 16S rRNA gene sequencing to profile the microbiome, paired with COI, 18S rRNA and ITS1 host phylogenies, phylosymbiosis was investigated in four groups of coral reef invertebrates (scleractinian corals, octocorals, sponges and ascidians). We tested three commonly used metrics to evaluate the extent of phylosymbiosis: (a) intraspecific versus interspecific microbiome variation, (b) topological comparisons between host phylogeny and hierarchical clustering (dendrogram) of host-associated microbial communities, and (c) correlation of host phylogenetic distance with microbial community dissimilarity.
View Article and Find Full Text PDFAccidental oil spills from shipping and during extraction can threaten marine biota, particularly coral reef species which are already under pressure from anthropogenic disturbances. Marine sponges are an important structural and functional component of coral reef ecosystems; however, despite their ecological importance, little is known about how sponges and their microbial symbionts respond to petroleum products. Here, we use a systems biology-based approach to assess the effects of water-accommodated fractions (WAF) of crude oil, chemically enhanced water-accommodated fractions of crude oil (CWAF), and dispersant (Corexit EC9500A) on the survival, metamorphosis, gene expression, and microbial symbiosis of the abundant reef sponge in larval laboratory-based assays.
View Article and Find Full Text PDFThe mitochondrial genetic diversity, distribution and invasive potential of multiple cryptic operational taxonomic units (OTUs) of the red invasive seaweed Asparagopsis were assessed by studying introduced Mediterranean and Hawaiian populations. Invasive behavior of each Asparagopsis OTU was inferred from phylogeographic reconstructions, past historical demographic dynamics, recent range expansion assessments and future distributional predictions obtained from demographic models. Genealogical networks resolved Asparagopsis gametophytes and tetrasporophytes into four A.
View Article and Find Full Text PDFSix species of Paramunida are reported from the continental margin of north-western Australia. Three species are new to science: Paramunida christinae sp. nov.
View Article and Find Full Text PDFThe red seaweed Asparagopsis taxiformis embodies five cryptic mitochondrial lineages (lineage 1-5) introduced worldwide as a consequence of human mediated transport and climate change. We compared globally collected mitochondrial cox2-3 intergenic spacer sequences with sequences produced from multiple Australian locations and South Korea to identify Asparagopsis lineages and to reveal cryptic introductions. We report A.
View Article and Find Full Text PDFMarine fungi are an understudied group of eukaryotic microorganisms characterized by unresolved genealogies and unstable classification. Whereas DNA barcoding via the nuclear ribosomal internal transcribed spacer (ITS) provides a robust and rapid tool for fungal species delineation, accurate classification of fungi is often arduous given the large number of partial or unknown barcodes and misidentified isolates deposited in public databases. This situation is perpetuated by a paucity of cultivable fungal strains available for phylogenetic research linked to these data sets.
View Article and Find Full Text PDFThe unrivalled level of biodiversity across the tropical Indo-Australian Archipelago (IAA) has been the subject of wide debate. Attempts to understand its origins have focussed on the timing of speciation, rates of diversification and the directionality of colonisation across geographical and climatic gradients in an array of marine groups. We investigate origins and evolution in the Choerodon tuskfishes, a group of labrids whose centre of diversity coincides with this region.
View Article and Find Full Text PDFSquat lobsters from Madagascar, Vanuatu, Papua New Guinea, Fiji, eastern Australia and French Polynesia belonging to the Agononida incerta (Henderson, 1888) species complex are described as four new species: A. madagascerta, A. polycerta, A.
View Article and Find Full Text PDFSurprisingly little is known of the toxic arsenal of cnidarian nematocysts compared to other venomous animals. Here we investigate the toxins of nematocysts isolated from the jellyfish Olindias sambaquiensis. A total of 29 unique ms/ms events were annotated as potential toxins homologous to the toxic proteins from diverse animal phyla, including cone-snails, snakes, spiders, scorpions, wasp, bee, parasitic worm and other Cnidaria.
View Article and Find Full Text PDFBackground: Understanding the mechanisms by which natural populations cope with environmental stress is paramount to predict their persistence in the face of escalating anthropogenic impacts. Reef-building corals are increasingly exposed to local and global stressors that alter nutritional status causing reduced fitness and mortality, however, these responses can vary considerably across species and populations.
Methodology/principal Findings: We compare the expression of 22 coral host genes in individuals from an inshore and an offshore reef location using quantitative Reverse Transcription-PCR (qRT-PCR) over the course of 26 days following translocation into a shaded, filtered seawater environment.
Maskrays of the genus Neotrygon (Dasyatidae) have dispersed widely in the Indo-West Pacific being represented largely by an assemblage of narrow-ranging coastal endemics. Phylogenetic reconstruction methods reproduced nearly identical and statistically robust topologies supporting the monophyly of the genus Neotrygon within the family Dasyatidae, the genus Taeniura being consistently basal to Neotrygon, and Dasyatis being polyphyletic to the genera Taeniurops and Pteroplatytrygon. The Neotrygon kuhlii complex, once considered to be an assemblage of color variants of the same biological species, is the most derived and widely dispersed subgroup of the genus.
View Article and Find Full Text PDFIdentification of taxonomical units underpins most biological endeavours ranging from accurate biodiversity estimates to the effective management of sustainably harvested, protected or endangered species. Successful species identification is now frequently based on a combination of approaches including morphometrics and DNA markers. Sequencing of the mitochondrial COI gene is an established methodology with an international campaign directed at barcoding all fishes.
View Article and Find Full Text PDFBiofilms of the bacterium Pseudoalteromonas induce metamorphosis of acroporid coral larvae. The bacterial metabolite tetrabromopyrrole (TBP), isolated from an extract of Pseudoalteromonas sp. associated with the crustose coralline alga (CCA) Neogoniolithon fosliei, induced coral larval metamorphosis (100%) with little or no attachment (0-2%).
View Article and Find Full Text PDFVibrio harveyi and related bacteria are important pathogens responsible for severe economic losses in the aquaculture industry worldwide. Phenotypic tests and 16S rRNA gene analysis fail to discriminate species within the V. harveyi group because these are phenotypically and genetically nearly identical.
View Article and Find Full Text PDFThe tropical to subtropical squat lobster Uroptychus nasoVan Dam, 1933 (Chirostylidae) is a widely distributed species originally described from Indonesia, subsequently reported from the Philippines, Taiwan, Japan and it has recently been discovered on the continental slope of north-western Australia. Populations of U. naso occur along the Indo-Pacific Ocean continental margin crossing the recently proposed marine analog of Wallace's line, responsible for past population fragmentation and ancient speciation.
View Article and Find Full Text PDFMol Biol Evol
January 2011
Nitric oxide (NO) is essential to many physiological functions and operates in several signaling pathways. It is not understood how and when the different isoforms of nitric oxide synthase (NOS), the enzyme responsible for NO production, evolved in metazoans. This study investigates the number and structure of metazoan NOS enzymes by genome data mining and direct cloning of Nos genes from the lamprey.
View Article and Find Full Text PDFThe red alga, Asparagopsis taxiformis, has recently expanded its distribution range into the Western Mediterranean Sea, and populations have now even been found on the Portuguese South coast. All Western Mediterranean populations belong to a single mitochondrial cryptic lineage (referred to as lineage 2 in earlier studies) and probably result from a recent invasion of Indo-Pacific origin. Here we investigate fine-scale population genetic diversity and structure within and among Mediterranean populations of lineage 2 using eight microsatellite loci and compare the obtained patterns with those observed in a Californian population of the same lineage.
View Article and Find Full Text PDFBackground: The study of ascidians (Chordata, Tunicata) has made a considerable contribution to our understanding of the origin and evolution of basal chordates. To provide further information to support forward genetics in Ciona intestinalis, we used a combination of natural variation and neutral population genetics as an approach for the systematic identification of new mutations. In addition to the significance of developmental variation for phenotype-driven studies, this approach can encompass important implications in evolutionary and population biology.
View Article and Find Full Text PDFBackground: The tunicate Ciona intestinalis (Enterogona, Ascidiacea), a major model system for evolutionary and developmental genetics of chordates, harbours two cryptic species. To assess the degree of intra- and inter-specific genetic variability, we report the identification and analysis of C. intestinalis SNP (Single Nucleotide Polymorphism) markers.
View Article and Find Full Text PDFEight polymorphic nuclear microsatellite loci were identified from the invasive Indo-Pacific Mediterranean strain of Asparagopsis taxiformis. Microsatellite markers were tested against a panel of specimens collected along the Italian (Elba, Naples) and Californian (Catalina Island) coasts, all belonging to the same mitochondrial lineage. In addition, we used Hawaiian specimens, belonging to a closely related mitochondrial lineage.
View Article and Find Full Text PDFThe rhodophyte seaweed Asparagopsis armata Harvey is distributed in the northern and southern temperate zones, and its congener Asparagopsis taxiformis (Delile) Trevisan abounds throughout the tropics and subtropics. Here, we determine intraspecific phylogeographic patterns to compare potential causes of the disjunctions in the distributions of both species. We obtained specimens throughout their ranges and inferred phylogenies from the hypervariable domains D1-D3 of the nuclear rDNA LSU, the plastid spacer between the large and small subunits of RuBisCo and the mitochondrial cox 2-3 intergenic spacer.
View Article and Find Full Text PDFWe applied independent species concepts to clarify the phylogeographic structure of the ascidian Ciona intestinalis, a powerful model system in chordate biology and for comparative genomic studies. Intensive research with this marine invertebrate is based on the assumption that natural populations globally belong to a single species. Therefore, understanding the true taxonomic classification may have implications for experimental design and data management.
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