FMRF-NH2-related neuropeptides in Biomphalaria spp., intermediate hosts for schistosomiasis: Precursor organization and immunohistochemical localization

Freshwater snails of the genus Biomphalaria serve as intermediate hosts for the digenetic trematode Schistosoma mansoni, the etiological agent for the most widespread form of intestinal schistosomiasis. As neuropeptide signaling in host snails can be altered by trematode infection, a neural transcriptomics approach was undertaken to identify peptide precursors in Biomphalaria glabrata, the major intermediate host for S. mansoni in the Western Hemisphere. Three transcripts that encode peptides belonging to the FMRF-NH2-related peptide (FaRP) family were identified in B. glabrata. One transcript encoded a precursor polypeptide (Bgl-FaRP1; 292 amino acids) that included eight copies of the tetrapeptide FMRF-NH2 and single copies of FIRF-NH2, FLRF-NH2, and pQFYRI-NH2. The second transcript encoded a precursor (Bgl-FaRP2; 347 amino acids) that comprised 14 copies of the heptapeptide GDPFLRF-NH2 and 1 copy of SKPYMRF-NH2. The precursor encoded by the third transcript (Bgl-FaRP3; 287 amino acids) recapitulated Bgl-FaRP2 but lacked the full SKPYMRF-NH2 peptide. The three precursors shared a common signal peptide, suggesting a genomic organization described previously in gastropods. Immunohistochemical studies were performed on the nervous systems of B. glabrata and B. alexandrina, a major intermediate host for S. mansoni in Egypt. FMRF-NH2-like immunoreactive (FMRF-NH2-li) neurons were located in regions of the central nervous system associated with reproduction, feeding, and cardiorespiration. Antisera raised against non-FMRF-NH2 peptides present in the tetrapeptide and heptapeptide precursors labeled independent subsets of the FMRF-NH2-li neurons. This study supports the participation of FMRF-NH2-related neuropeptides in the regulation of vital physiological and behavioral systems that are altered by parasitism in Biomphalaria

Cephalopod genomics: a plan of strategies and organization

The Cephalopod Sequencing Consortium (CephSeq Consortium) was established at a NESCent Catalysis Group Meeting, "Paths to Cephalopod Genomics-Strategies, Choices, Organization," held in Durham, North Carolina, USA on May 24-27, 2012. Twenty-eight participants representing nine countries (Austria, Australia, China, Denmark, France, Italy, Japan, Spain and the USA) met to address the pressing need for genome sequencing of cephalopod mollusks. This group, drawn from cephalopod biologists, neuroscientists, developmental and evolutionary biologists, materials scientists, bioinformaticians and researchers active in sequencing, assembling and annotating genomes, agreed on a set of cephalopod species of particular importance for initial sequencing and developed strategies and an organization (CephSeq Consortium) to promote this sequencing. The conclusions and recommendations of this meeting are described in this white paper

An accurate fluorescent assay for quantifying the extent of RNA editing

Recent data suggest that small differences in editing efficiency can have significant functional consequences. Here we present a fluorescent poisoned primer extension assay that is capable of distinguishing editing efficiency differences as low as 5%. For a poison-primer extension assay to be accurate, the extension product must stop at the intended base. Sometimes, however, it runs beyond. We tested the effect of specific enzyme–terminator combinations on the amount of run through. In the worst cases it accounted for 70% of the total signal, and in the best cases <5%. In addition, the specific base can affect run through, with G producing the least. The accuracy of the assay was demonstrated on templates derived from mixed plasmids and then verified on two biological substrates. Using either a K(+) channel mRNA that contains a site for adenosine deamination or an ndhB mRNA that contains a site for cytidine deamination, the editing efficiency predicted by the assay closely matched that predicted by bulk sequencing of individual cDNA clones. This assay should prove useful for analyzing small changes in editing efficiency or for quantifying single nucleotide polymorphisms

Whole-exome sequencing identifies rare and low-frequency coding variants associated with LDL cholesterol

Elevated low-density lipoprotein cholesterol (LDL-C) is a treatable, heritable risk factor for cardiovascular disease. Genome-wide association studies (GWASs) have identified 157 variants associated with lipid levels but are not well suited to assess the impact of rare and low-frequency variants. To determine whether rare or low-frequency coding variants are associated with LDL-C, we exome sequenced 2,005 individuals, including 554 individuals selected for extreme LDL-C (>98th or <2nd percentile). Follow-up analyses included sequencing of 1,302 additional individuals and genotype-based analysis of 52,221 individuals. We observed significant evidence of association between LDL-C and the burden of rare or low-frequency variants in PNPLA5, encoding a phospholipase-domain-containing protein, and both known and previous