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Abstract: The feeding environment for planktotrophic larvae has a major impact on development and progression towards competency for metamorphosis. High phytoplankton environments that promote growth and development also correlate with a greater abundance of environmental microbes and incidence of pathogenic microbes, making these habitats potentially risky for larvae. Trade‐offs between metabolic processes for growth and immune functionality have been described throughout the animal kingdom and may influence the life‐history evolution of marine invertebrate planktotrophic larvae. Specifically, larvae would be predicted to regulate time spent between these feeding environments to avoid potential incidences of microbial‐mediated mortality and/or dysbiosis. Using transcriptomic and microbiome data, we provide evidence for this trade‐off in larvae of the sea urchin Strongylocentrotus droebachiensis. When cultured in a well‐fed environment, larvae upregulate genes associated with metabolism while decreasing the expression of genes associated with immune function. At the same time, the associated bacterial community shifts towards a state of dysbiosis that is followed by mortality. To test whether the environmental microbiota is a selective force on if, where and when planktotrophic larvae should feed, we conclude by presenting a strategy for determining the specific interactions of larvae and microbes at a scale representative of their pelagic environment. [ABSTRACT FROM AUTHOR]

Clonal propagation is an important life history trait for many sessile organisms, and often leads to the formation of monoclonal aggregations. In the marine environment, sea anemones have been model species for testing theory regarding the evolution of sex and understanding the contribution of sexual versus asexual reproduction to the population structure in facultatively clonal animals. However, little attention has been paid to tropical actiniarians. The corkscrew anemone Bartholomea annulata is common in tropical marine habitats in the western Atlantic and Caribbean; it forms small aggregations (2-4 anemones) on coral reefs and larger aggregations (>10 anemones) in mangrove habitats. We used field surveys and molecular analyses to investigate patterns of distribution, abundance, and genetic structure of aggregations formed by B. annulata on a reef in the US Virgin Islands and in a unique mangrove habitat in the Florida Keys. Abundance was greatest at the abandoned rock quarry mangrove habitat in the Florida Keys, where anemones formed continuously distributed aggregations carpeting the exposed limestone walls. Genetic diversity assessed via intersimple sequence repeats ( ISSRs) and six microsatellite loci revealed that asexual reproduction plays only a minor role in the formation of both small and large anemone aggregations. Specifically, ISSR analyses showed that only ~10% of anemone aggregations were clonal in the US Virgin Islands, while microsatellite genotyping identified clonality in only 1 of 35 aggregations. In the Florida Keys, only four clonal genotypes were recovered within aggregations, but eight clones, representing 33% of the total surveyed population, had individuals in multiple aggregations. Thus, population structure of B. annulata appears to rely primarily on sexual reproduction, although asexual reproduction may play a nontrivial role in some environments. Mechanisms that drive the formation of genotypically diverse aggregations remain unknown, but may include attraction toward conspecifics, shared use of preferred habitats, or the local retention of larvae in partially enclosed habitats. [ABSTRACT FROM AUTHOR]

Camelina ( Camelina sativa), a Brassicaceae oilseed, has received recent interest as a biofuel crop and production platform for industrial oils. Limiting wider production of camelina for these uses is the need to improve the quality and content of the seed protein-rich meal and oil, which is enriched in oxidatively unstable polyunsaturated fatty acids that are deleterious for biodiesel. To identify candidate genes for meal and oil quality improvement, a transcriptome reference was built from 2047 Sanger ESTs and more than 2 million 454-derived sequence reads, representing genes expressed in developing camelina seeds. The transcriptome of approximately 60K transcripts from 22 597 putative genes includes camelina homologues of nearly all known seed-expressed genes, suggesting a high level of completeness and usefulness of the reference. These sequences included candidates for 12 S (cruciferins) and 2 S (napins) seed storage proteins ( SSPs) and nearly all known lipid genes, which have been compiled into an accessible database. To demonstrate the utility of the transcriptome for seed quality modification, seed-specific RNAi lines deficient in napins were generated by targeting 2 S SSP genes, and high oleic acid oil lines were obtained by targeting FATTY ACID DESATURASE 2 ( FAD2) and FATTY ACID ELONGASE 1 ( FAE1). The high sequence identity between Arabidopsis thaliana and camelina genes was also exploited to engineer high oleic lines by RNAi with Arabidopsis FAD2 and FAE1 sequences. It is expected that these transcriptomic data will be useful for breeding and engineering of additional camelina seed traits and for translating findings from the model Arabidopsis to an oilseed crop. [ABSTRACT FROM AUTHOR]

The plains topminnow ( Fundulus sciadicus) is a killifish endemic to the Great Plains region. Recent field surveys indicate that populations may be declining in northerly portions of its range and perhaps throughout. Here, we describe the isolation and characterization of 11 microsatellite loci developed for population genetic studies in the species. We also conducted cross-species amplifications to test primer efficacy in five additional taxa, including four killifishes. [ABSTRACT FROM AUTHOR]