Contaminated Turmeric Is a Potential Source of Lead Exposure for Children in Rural Bangladesh

Background. During the conduct of a cohort study intended to study the associations between mixed metal exposures and child health outcomes, we found that 78% of 309 children aged 20–40 months evaluated in the Munshiganj District of Bangladesh had blood lead concentrations ≥5 µg/dL and 27% had concentrations ≥10 µg/dL. Hypothesis. Environmental sources such as spices (e.g., turmeric, which has already faced recalls in Bangladesh due to high lead levels) may be a potential route of lead exposure. Methods. We conducted visits to the homes of 28 children randomly selected from among high and low blood lead concentration groups. During the visits, we administered a structured questionnaire and obtained soil, dust, rice, and spice samples. We obtained water samples from community water sources, as well as environmental samples from neighborhood businesses. Results. Lead concentrations in many turmeric samples were elevated, with lead concentrations as high as 483 ppm. Analyses showed high bioaccessibility of lead. Conclusions. Contamination of turmeric powder is a potentially important source of lead exposure in this population

Extreme plasticity in reproductive biology of an oviparous lizard

Most oviparous squamate reptiles lay their eggs when embryos have completed less than one‐third of development, with the remaining two‐thirds spent in an external nest. Even when females facultatively retain eggs in dry or cold conditions, such retention generally causes only a minor (\u3c10%) decrease in subsequent incubation periods. In contrast, we found that female sand lizards (Lacerta agilis) from an experimentally founded field population (established ca. 20 years ago on the southwest coast of Sweden) exhibited wide variation in incubation periods even when the eggs were kept at standard (25°C) conditions. Females that retained eggs in utero for longer based on the delay between capture and oviposition produced eggs that hatched sooner. In the extreme case, eggs hatched after only 55% of the normal incubation period. Although the proximate mechanisms underlying this flexibility remain unclear, our results from this first full field season at the new study site show that females within a single cold‐climate population of lizards can span a substantial proportion of the continuum from normal oviparity to viviparity

Pharmacological Restoration of Visual Function in a Blind Zebrafish Mutant Following Histone Deacetylase Inhibitor (HDACi) Treatment

Background: Controversially, histone deacetylase (HDAC) inhibitors are in clinical trial for the treatment of inherited retinal degenerations. Previous studies report that patients suffering from Retinitis Pigmentosa (RP) show improved visual field and acuity following treatment with the HDAC inhibitor valproic acid (VPA) (Clemson, Tzekov et al. 2011). However, other studies disagree with these findings (van Schooneveld, van den Born et al. 2011) and (Bhalla, Joshi et al. 2013). Thus, we sought to determine if treatment with HDACi rescued visual function and retinal morphology in a blind zebrafish dying-on-edge (dye) mutant identified from a forward genetics screen

Genes and signaling networks regulated during zebrafish optic vesicle morphogenesis

Background: The genetic cascades underpinning vertebrate early eye morphogenesis are poorly understood. One gene family essential for eye morphogenesis encodes the retinal homeobox (Rx) transcription factors. Mutations in the human retinal homeobox gene (RAX) can lead to gross morphological phenotypes ranging from microphthalmia to anophthalmia. Zebrafish rx3 null mutants produce a similar striking eyeless phenotype with an associated expanded forebrain. Thus, we used zebrafish rx3-/- mutants as a model to uncover an Rx3-regulated gene network during early eye morphogenesis. Results: Rx3-regulated genes were identified using whole transcriptomic sequencing (RNA-seq) of rx3-/- mutants and morphologically wild-type siblings during optic vesicle morphogenesis. A gene co-expression network was then constructed for the Rx3-regulated genes, identifying gene cross-talk during early eye development. Genes highly connected in the network are hub genes, which tend to exhibit higher expression changes between rx3-/- mutants and normal phenotype siblings. Hub genes down-regulated in rx3-/- mutants encompass homeodomain transcription factors and mediators of retinoid-signaling, both associated with eye development and known human eye disorders. In contrast, genes up-regulated in rx3-/- mutants are centered on Wnt signaling pathways, associated with brain development and disorders. The temporal expression pattern of Rx3-regulated genes was further profiled during early development from maternal stage until visual function is fully mature. Rx3-regulated genes exhibited synchronized expression patterns, and a transition of gene expression during the early segmentation stage when Rx3 was highly expressed. Furthermore, most of these deregulated genes are enriched with multiple RAX-binding motif sequences on the gene promoter. Conclusions: Here, we assembled a comprehensive model of Rx3-regulated genes during early eye morphogenesis. Rx3 promotes optic vesicle morphogenesis and represses brain development through a highly correlated and modulated network, exhibiting repression of genes mediating Wnt signaling and concomitant enhanced expression of homeodomain transcription factors and retinoid-signaling genes.Irish Research Council for Science, Engineering and TechnologyBiochemical Society Summer Vacation Studentshi

A s i o r a p h

for more information go to: i l