Primera cita de Caulerpa cylindracea (Caulerpaceae, Chlorophyta) en Andalucía (Sur de España)

Three different species of Caulerpa (Caulerpaceae, Chlorophyta) co-occur in the Mediterranean Sea: two of them are found at the central-eastern basin and are typically considered non aggressive components of the Lessepsian flora [(C. chemnitzia(Esper) J.V. Lamouroux and C. racemosa var. lamourouxii (Turner) Weber-van Bosse f. requienii(Montagne) Weber van Bosse)]; a third taxon, C. cylindracea Sonder has aggressively expanded its range since its first observation in 1990, and it is nowadays reported from nearly all the Mediterranean countries. We report a population of C. cylindracea from Almería (Andalusia, Southern Iberian Peninsula) at −30 m depth as to be the westernmost record of the invasive variety on the Mediterranean European coast. Therefore, we made use of morphological description and molecular phylogenetics to provide a complete identification of this invasive seaweed in Southern Spain. Our findings are discussed in light of the composition of the receptor communities, such as maërl bed, edges of Posidonia oceanica (Linnaeus) Delile, and their ecology. Our results confirmed the suggested directionality of the invasive pathway to be westward to the Strait of Gibraltar, mainly supported by sea currents and vectors of anthropogenic origin.En el Mar Mediterráneo se encuentran tres especies diferentes de Caulerpa (Caulerpaceae, Chlorophyta): dos de ellas se localizan en la cuenca centro oriental y se consideran componentes no agresivos de la flora Lessepsiana (C. chemnitzia (Esper) J.V. Lamouroux and C. racemosa var. lamourouxii (Turner) Weber-van Bosse f. requienii (Montagne) Weber van Bosse); un tercer taxon, C. cylindracea Sonder ha expandido de manera agresiva su rango de distribución desde su primera observación en 1990, y actualmente se registra en casi todos los países de la cuenca mediterránea. En este trabajo se informa sobre una población de C. cylindracea en Almería (Andalucía, Sur de España), a −30 m de profundidad, que representaría la cita más occidental de la variedad invasora en las costas mediterráneas europeas. Se realiza una completa identificación de esta alga invasora en el Sur de España mediante una descripción morfológica y filogenia molecular. Los datos obtenidos se discuten en relación a la composición de las comunidades receptoras, tales como fondos de maërl y bordes de Posidonia oceanica (Linnaeus) Delile, y su ecología. Los resultados confirman la direccionalidad de la ruta invasora de la especie hacia el oeste en las proximidades del Estrecho de Gibraltar, principalmente debido a corrientes marinas y vectores de origen antropogénico.This work has been founded by the projects CGL2008/01549/BOS and CGL2008/02298/BOS (Ministerio de Ciencia e Innovación), P09-RNM-5187 (Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía), 806/5.03.3553 and 806/5.03.3673 (Instituto de Estudios Ceutíes), and has been developed in the framework of the Research Collaboration Agreement between Consejería de Medio Ambiente de la Junta de Andalucía and the University of Málaga

Differential regulation of the zebrafish orthopedia1 gene during fate determination of diencephalic neurons

BACKGROUND: The homeodomain transcription factor Orthopedia (Otp) is essential in restricting the fate of multiple classes of secreting neurons in the neuroendocrine hypothalamus of vertebrates. However, there is little information on the intercellular factors that regulate Otp expression during development. RESULTS: Here, we identified two otp orthologues in zebrafish (otp1 and otp2) and explored otp1 in the context of the morphogenetic pathways that specify neuroectodermal regions. During forebrain development, otp1 is expressed in anterior groups of diencephalic cells, positioned in the preoptic area (PO) (anterior alar plate) and the posterior tuberculum (PT) (posterior basal plate). The latter structure is characterized by Tyrosine Hydroxylase (TH)-positive cells, suggesting a role for otp1 in the lineage restriction of catecholaminergic (CA) neurons. Disruptions of Hedgehog (HH) and Fibroblast Growth Factor (FGF) pathways point to the ability of SHH protein to trigger otp1 expression in PO presumptive neuroblasts, with the attenuating effect of Dzip1 and FGF8. In addition, our data disclose otp1 as a determinant of CA neurons in the PT, where otp1 activity is strictly dependent on Nodal signaling and it is not responsive to SHH and FGF. CONCLUSION: In this study, we pinpoint the evolutionary importance of otp1 transcription factor in cell states of the diencephalon anlage and early neuronal progenitors. Furthermore, our data indicate that morphogenetic mechanisms differentially regulate otp1 expression in alar and basal plates

Natural Variation of Model Mutant Phenotypes in Ciona intestinalis

BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report a preliminary survey for naturally occurring mutations in three geographically interconnected populations of C. intestinalis. The influence of historical, geographical and environmental factors on the distribution of abnormal phenotypes was assessed by means of 12 microsatellites. We identified 37 possible mutant loci with stereotyped defects in embryonic development that segregate in a way typical of recessive alleles. Local populations were found to differ in genetic organization and frequency distribution of phenotypic classes. CONCLUSIONS/SIGNIFICANCE: Natural genetic polymorphism of C. intestinalis constitutes a valuable source of phenotypes for studying embryonic development in ascidians. Correlating genetic structure and the occurrence of abnormal phenotypes is a crucial focus for understanding the selective forces that shape natural finite populations, and may provide insights of great importance into the evolutionary mechanisms that generate animal diversity

Towards an integrative phylogeography of invasive marine seaweeds, based on multiple lines of evidence

Molecular phylogeography has for decades been a frequently used approach to delineate novel evolutionarily significant units (ESUs) and to study the dynamics of invasive species. Next-generation sequencing technology (NGS) and the use of environmental DNA (eDNA) have the potential to revolutionize our way of understanding biodiversity and to establish rapid protocols for early-stage detection of invasive species. In seaweeds, however, several years of research on iconic invasive taxa of ambiguous taxonomic status (e.g. Caulerpa, Codium, Asparagopsis) have suggested that an integrative approach, namely the combination of multiple lines of evidence (e.g. phylogeographic, ecological, physiological and predictive modelling), is necessary to accurately resolve the taxonomy and their invasive potential. At present, integrative approaches in these fields are often weak because of incongruences among species delineation, newly discovered ESUs which remain undescribed taxonomically, and because databases containing vouchers of barcoded specimens are incomplete. As relocations of marine biota accelerate and climatic changes offer new potential niches for invasive seaweeds, new, transferable and internationally adopted protocols are necessary for exploring, monitoring and managing marine biodiversity. This is particularly urgent in areas of intense maritime traffic, such as the Mediterranean Sea and the Hawaiian archipelago, in order to achieve sustainable socio-economic development without compromising the local marine resources

Evolution of the SOUL Heme-Binding Protein Superfamily Across Eukarya

International audienceSOUL homologs constitute a heme-binding protein superfamily putatively involved in heme and tetrapyrrole metabolisms associated with a number of physiological processes. Despite their omnipresence across the tree of life and the biochemical characterization of many SOUL members, their functional role and the evolutionary events leading to such remarkable protein repertoire still remain cryptic. To explore SOUL evolution, we apply a computational phylogenetic approach, including a relevant number of SOUL homologs, to identify paralog forms and reconstruct their genealogy across the tree of life and within species. In animal lineages, multiple gene duplication or loss events and paralog functional specializations underlie SOUL evolution from the dawn of ancestral echinoderm and mollusc SOUL forms. In photosynthetic organisms, SOUL evolution is linked to the endosymbiosis events leading to plastid acquisition in eukaryotes. Derivative features, such as the F2L peptide and BH3 domain, evolved in vertebrates and provided innovative functionality to support immune response and apoptosis. The evolution of elements such as the N-terminal protein domain DUF2358, the His42 residue, or the tetrapyrrole heme-binding site is modern, and their functional implications still unresolved. This study represents the first in-depth analysis of SOUL protein evolution and provides novel insights in the understanding of their obscure physiological role

More species of the Agononida incerta complex revealed by molecules and morphology (Crustacea: Decapoda: Anomura: Munididae)

Poore, Gary C. B., Andreakis, Nikos (2014): More species of the Agononida incerta complex revealed by molecules and morphology (Crustacea: Decapoda: Anomura: Munididae). Zootaxa 3860 (3): 201-225, DOI: 10.11646/zootaxa.3860.3.

FIGURE 5. A in New records and new species of the munidopsine squat lobsters (Decapoda: Anomura: Galatheidae: Munidopsinae) from Australia

FIGURE 5. A, Galacantha subspinosa Macpherson, 2007, lateral view, NMV J56403; B, dorsal view. C, Munidopsis andamanica MacGilchrist, 1905, lateral view, NMV J55015, D, dorsal view; E, Munidopsis crenatirostris Baba, 1988, dorsal view, NMV J56397; F, Munidopsis dasypus Alcock, 1894, dorsal view, NMV J55006; G, Munidopsis kenselyi Ahyong & Poore, 2004, dorsal view, NMV J57251; H, Munidopsis vesper sp. nov., dorsal view, holotype male WAM C45482. All photographs copyright CSIRO.Published as part of Taylor, Joanne, Ahyong, Shane T. & Andreakis, Nikos, 2010, New records and new species of the munidopsine squat lobsters (Decapoda: Anomura: Galatheidae: Munidopsinae) from Australia, pp. 1-18 in Zootaxa 2642 on page 13, DOI: 10.5281/zenodo.19863

Cryptic speciation and phylogeographic relationships in the elephant ear sponge Ianthella basta (Porifera, Ianthellidae) from northern Australia

Morphological delineation of sponge species is hindered by the narrow range of fixed diagnostic characters and our limited knowledge of how much phenotypic plasticity the sponge body plan assumes in response to environmental conditions. Here, we make use of the partial mitochondrial cytochrome c oxidase subunit I (COI) gene and the second internal transcribed spacer (ITS2) region to assess the taxonomic validity of colour morphotypes observed in the elephant ear sponge Ianthella basta (Pallas, 1776) across its distribution range in northern Australia, and explore levels and patterns of genetic diversity among populations of the species collected from both sides of the Torres Strait. Molecular phylogenetic analyses revealed congruent topologies consistent with three evolutionarily significant units (ESUs) that were independent of the morphology of the sponge. ESU I includes previously morphologically and genetically delineated western Pacific specimens of I. basta (Guam), and probably corresponds to the type specimen originally described from Indonesia. ESU I occurs in almost all sampling sites across northern Australia, suggesting considerable levels of connectivity among reefs throughout the Torres Strait. ESUs II and III are each exclusively associated with a geographic region of high sponge species richness separated by Torres Strait, and probably represent the result of historical population fragmentation

SNPs and Hox gene mapping in <it>Ciona intestinalis</it>

<p>Abstract</p> <p>Background</p> <p>The tunicate <it>Ciona intestinalis </it>(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 <it>C. intestinalis </it>SNP (Single Nucleotide Polymorphism) markers. A SNP subset was used to determine the genetic distance between <it>Hox-5 </it>and <it>-10 </it>genes.</p> <p>Results</p> <p>DNA fragments were amplified from 12 regions of <it>C. intestinalis </it>sp. A. In total, 128 SNPs and 32 one bp indels have been identified within 8 Kb DNA. SNPs in coding regions cause 4 synonymous and 12 non-synonymous substitutions. The highest SNP frequency was detected in the <it>Hox5 </it>and <it>Hox10 </it>intragenic regions. In <it>C. intestinalis</it>, these two genes have lost their archetypal topology within the cluster, such that <it>Hox10 </it>is located between <it>Hox4 </it>and <it>Hox5</it>. A subset of the above primers was used to perform successful amplification in <it>C. intestinalis </it>sp. B. In this cryptic species, 62 SNPs were identified within 3614 bp: 41 in non-coding and 21 in coding regions. The genetic distance of the <it>Hox-5 </it>and <it>-10 </it>loci, computed combining a classical backcross approach with the application of SNP markers, was found to be 8.4 cM (Haldane's function). Based on the physical distance, 1 cM corresponds to 39.5 Kb. Linkage disequilibrium between the aforementioned loci was calculated in the backcross generation.</p> <p>Conclusion</p> <p>SNPs here described allow analysis and comparisons within and between <it>C. intestinalis </it>cryptic species. We provide the first reliable computation of genetic distance in this important model chordate. This latter result represents an important platform for future studies on Hox genes showing deviations from the archetypal topology.</p

A multiplex PCR-based protocol for identification and quantification of Vibrio harveyi-related species

Vibrios of the Harveyi clade are responsible for severe economic losses in the aquaculture industry worldwide, but so far no rapid method has been available to discriminate between the closely related species Vibrio campbellii, Vibrio harveyi, Vibrio owensii and Vibrio rotiferianus. Here, we describe a multiplex PCR assay capable of fast and reliable detection and identification of these species by amplification of three conserved protein-coding genes (topA, ftsZ and mreB). The developed species-specific primer sets produce PCR amplicons of unequal length and can be used separately or in combination. When combined with a 3-tube most-probable-number (MPN) based protocol, the multiplex PCR allows highly sensitive detection and enumeration in complex, aquaculture-relevant samples such as water, Artemia and spiny lobster (Panulirus ornatus) larvae. The described multiplex PCR represents a significant advance for aquaculture by providing an easy, fast and low-cost method for identification of several closely related pathogens that are difficult to discriminate by traditional approaches