Significant genetic differentiation among populations of Anomalocardia brasiliana (Gmelin, 1791): A bivalve with planktonic larval dispersion

Four Brazilian populations of Anomalocardia brasiliana were tested for mutual genetic homogeneity, using data from 123 sequences of the mtDNA cytochrome oxidase c subunit I gene. A total of 36 haplotypes were identified, those shared being H3 (Canela Island, Prainha and Acupe) and both H5 and H9 (Prainha and Acupe). Haplotype diversity values were high, except for the Camurupim population, whereas nucleotide values were low in all the populations, except for that of Acupe. Only the Prainha population showed a deviation from neutrality and the SSD test did not reject the demographic expansion hypothesis. Fst values showed that the Prainha and Acupe populations represent a single stock, whereas in both the Canela Island and Camurupim stocks, population structures are different and independent. The observed structure at Canela Island may be due to the geographic distance between this population and the remainder. The Camurupim population does not share any haplotype with the remaining populations in northeastern Brazil. The apparent isolation could be due to the rocky barrier located facing the mouth of the Mamanguape River. The results highlight the importance of wide-scale studies to identify and conserve local genetic diversity, especially where migration is restricted

Eag and HERG potassium channels as novel therapeutic targets in cancer

Voltage gated potassium channels have been extensively studied in relation to cancer. In this review, we will focus on the role of two potassium channels, Ether à-go-go (Eag), Human ether à-go-go related gene (HERG), in cancer and their potential therapeutic utility in the treatment of cancer. Eag and HERG are expressed in cancers of various organs and have been implicated in cell cycle progression and proliferation of cancer cells. Inhibition of these channels has been shown to reduce proliferation both in vitro and vivo studies identifying potassium channel modulators as putative inhibitors of tumour progression. Eag channels in view of their restricted expression in normal tissue may emerge as novel tumour biomarkers

Annual to Millennial Record of Sediment Delivery to US Virgin Island Coastal Environments

Over 100 sediment cores were collected from US Virgin Island coastal marine and salt pond environments to document the record of sediment delivery to the coastal system on annual to millennial time scales, and the extent to which human activities have influenced sedimentation patterns. Cores were analyzed for sedimentology, geochronology (210Pb, 137Cs, 7Be and 14C), and high-resolution elemental composition (scanning x-ray fluorescence (XRF) and laser ablation inductively coupled mass spectrometry (LA–ICP–MS)). The centennial–millennial record reveals the natural transition from terrestrial to marine ~6–4 kya in response to the Holocene sea-level rise. Coastal salt pond cores record initial pond development as coral growth between island headlands cut off and isolated existing marine embayments ~2 kya. The decadal–centennial record is dominated by human activities, primarily road construction, manifested as a ~10× increase in sediment accumulation rate where development is heavy, a ~2.5× increase where development is moderate, and no detectable increase in undeveloped areas. Annual millimeter- to centimeter-scale laminae in salt pond cores represent individual depositional ‘events’. Light-colored, Ca- and Sr-rich sands represent marine overwash deposits that in some cases can be tied to tropical cyclones. Dark-colored Al-, Fe-, Ti-, Si-rich sandy muds represent island runoff when rainfall rates exceed a threshold of ~1.2 cm/day. Organic-rich layers represent microbial mat growth between depositional ‘events’. Marine overwash and rainfall/runoff layers fluctuate on an annual–decadal scale during the historical period, but show much more variability over the previous ~1400 years, suggesting sediment source(s), depositional processes, and/or driving mechanisms have not remained constant during at least the late Holocene