Genetic homogeneity of the invasive lionfish across the Northwestern Atlantic and the Gulf of Mexico based on Single Nucleotide Polymorphisms.

Despite the devastating impact of the lionfish (Pterois volitans) invasion on NW Atlantic ecosystems, little genetic information about the invasion process is available. We applied Genotyping by Sequencing techniques to identify 1,220 single nucleotide polymorphic sites (SNPs) from 162 lionfish samples collected between 2013 and 2015 from two areas chronologically identified as the first and last invaded areas in US waters: the east coast of Florida and the Gulf of Mexico. We used population genomic analyses, including phylogenetic reconstruction, Bayesian clustering, genetic distances, Discriminant Analyses of Principal Components, and coalescence simulations for detection of outlier SNPs, to understand genetic trends relevant to the lionfish's long-term persistence. We found no significant differences in genetic structure or diversity between the two areas (FST p-values > 0.01, and t-test p-values > 0.05). In fact, our genomic analyses showed genetic homogeneity, with enough gene flow between the east coast of Florida and Gulf of Mexico to erase previous signals of genetic divergence detected between these areas, secondary spreading, and bottlenecks in the Gulf of Mexico. These findings suggest rapid genetic changes over space and time during the invasion, resulting in one panmictic population with no signs of divergence between areas due to local adaptation.

Genomic variation among populations of threatened coral: Acropora cervicornis.

BACKGROUND: Acropora cervicornis, a threatened, keystone reef-building coral has undergone severe declines (>90 %) throughout the Caribbean. These declines could reduce genetic variation and thus hamper the species' ability to adapt. Active restoration strategies are a common conservation approach to mitigate species' declines and require genetic data on surviving populations to efficiently respond to declines while maintaining the genetic diversity needed to adapt to changing conditions. To evaluate active restoration strategies for the staghorn coral, the genetic diversity of A. cervicornis within and among populations was assessed in 77 individuals collected from 68 locations along the Florida Reef Tract (FRT) and in the Dominican Republic. RESULTS: Genotyping by Sequencing (GBS) identified 4,764 single nucleotide polymorphisms (SNPs). Pairwise nucleotide differences (π) within a population are large (~37 %) and similar to π across all individuals. This high level of genetic diversity along the FRT is similar to the diversity within a small, isolated reef. Much of the genetic diversity (>90 %) exists within a population, yet GBS analysis shows significant variation along the FRT, including 300 SNPs with significant FST values and significant divergence relative to distance. There are also significant differences in SNP allele frequencies over small spatial scales, exemplified by the large FST values among corals collected within Miami-Dade county. CONCLUSIONS: Large standing diversity was found within each population even after recent declines in abundance, including significant, potentially adaptive divergence over short distances. The data here inform conservation and management actions by uncovering population structure and high levels of diversity maintained within coral collections among sites previously shown to have little genetic divergence. More broadly, this approach demonstrates the power of GBS to resolve differences among individuals and identify subtle genetic structure, informing conservation goals with evolutionary implications.

Motorcycle taxi drivers and sexually transmitted infections in a Peruvian Amazon City.

BACKGROUND: In Iquitos, Peru, motorcycle taxis are a common form of public transportation used both by residents and visitors. GOAL: To evaluate the prevalence of factors associated with sexually transmitted disease risk and of Neisseria gonorrhoeae and Chlamydia trachomatis infections among motorcycle taxi drivers working in Iquitos, Peru. STUDY DESIGN: A convenience sample of motorcycle taxi drivers was recruited through street outreach. Participants were confidentially interviewed and provided urine specimens for gonococcal and chlamydial infection testing. RESULTS: A history of sexually transmitted disease (62%) or symptoms in the past year (35%) and of referral of clients to commercial sex workers (60%) was common. The prevalence of gonococcal or chlamydial infection was 3.5%. CONCLUSIONS: Motorcycle taxi drivers are a major means of public transportation in Iquitos, Peru, have high personal risks for sexually transmitted disease, and interface often with at-risk persons.

Allozyme diversity in endemic flowering plant species of the Juan Fernandez Archipelago, Chile: ecological and historical factors with implications for conservation.

The level and apportionment of allozyme diversity were determined for 29 endemic (and 1 native) species from the Juan Fernández Islands, Chile. Mean diversities at the species level (H(es) = 0.065) are low but comparable to those measured for other insular endemics in the Pacific. A high mean proportion (0.338) of species-level diversity resides among populations. Diversity statistics were compared for species in different ecological-life history trait categories and abundance classes. Species occurring in large populations and those present in scattered small populations have higher diversities than species occurring in one or two populations. Although not significant with the conservative statistical test employed, lower diversity was found in highly selfing species as compared to animal- or wind-pollinated species. The apportionment of genetic diversity within and among populations (G(ST) values) is not significantly different for any of the species categories. Of particular interest is the lack of difference between animal- and wind-pollinated species because previous analyses of large data sets showed higher differentiation between populations of animal- than wind-pollinated species. Historical factors, both ecological and phylogenetic in nature, can influence the level and apportionment of diversity within insular endemics, and thus ecological correlates of diversity seen in many continental species may not apply to endemics. The results have several conservation implications. The preservation of large populations or several small populations is important for conserving diversity within species because when species are reduced to one or two populations, allozyme diversity is sharply reduced. High mean G(ST) values for the species examined illustrate the need for conserving as many populations as possible, either in the wild or in the garden, to preserve maximal diversity within species. Effective conservation strategies require empirical knowledge of each species.

Changes in cerebral blood flow associated with premenstrual syndrome: a preliminary study.

The purpose of this study was to determine changes in regional cerebral blood flow (rCBF) associated with premenstrual syndrome (PMS). Regional CBF was examined using single photon emission computed tomography (SPECT) in seven women who sought treatment for PMS and seven control subjects. Confirmation of PMS was based on the Daily Symptom Report (DSR) of 17 common symptoms associated with PMS. A first SPECT scan was performed near the peak of premenstrual symptoms based on DSR reports from the two previous cycles. A second scan was performed in the postmenstrual period. Prior to scanning, each subject had a Hamilton Depression Rating Scale (Ham-D) obtained. Regions of interest were drawn on the images to generate mean counts per pixel, and normalized to the cerebellum. Activity in the frontal, temporal and parieto-occipital cortices, and the thalami and basal ganglia, were compared between the two scans. Correlations between activity in each region of interest and Ham-D values were also determined. There were marked decreases in rCBF in the temporal lobes on the premenstrual scan compared to the postmenstrual scan in PMS patients. Significant correlations were observed between the change in rCBF in the right and left temporal lobes and the changes in Ham-D scores (r = 0.91, p < 0.01 and r = 0.86, p = 0.01 respectively). No rCBF changes were observed in controls. We conclude that SPECT imaging demonstrates modest decreases in rCBF in the temporal lobes that correlate with the level of depression in subjects with PMS.

The potassium impermeable apical membrane of insect epithelia: a target for development of safe pesticides.

Columnar cell apical membranes (CCAM) in series with goblet cell apical membranes (GCAM) form an electroosmotic barrier separating the midgut lumen from epithelial cell cytoplasm. A unique K+ ATPase in GCAM generates three gradients across this barrier. A greater than 180 mV electrical gradient (lumen positive) drives amino acid uptake through voltage-dependent K+ symports. A greater than 1000-fold [H+] gradient (lumen alkaline) and a greater than 10-fold [K+] gradient (lumen concentrated) are adaptations to the high tannin and high K+ content, respectively, in dietary plant material. Agents which act on the apical membrane and disrupt the PD, H+, or K+ gradients are potential insecticides. Insect sensory epithelia and mammalian stria vascularis maintain similar PD and K+ gradients but would not be exposed to ingested anti-apical membrane insecticides. Following the demonstration by Sacchi et al. that Bacillus thuringiensis delta-endotoxin (Bt) induces specifically a K+ conductance increase in CCAM vesicles, we find that the K+ channel blocking agent, Ba2+, completely reverses Bt inhibition of the K+-carried short circuit current in the isolated midgut of Manduca sexta. Progress in characterizing the apical membrane includes finding that fluorosulfonylbenzoyladenosine binds specifically to certain GCAM polypeptides and that CCAM vesicles can be mass produced by Ca2+ or Mg2+ precipitation from Manduca sexta midgut.