Pontamine sky blue: a counterstain for background autofluorescence in fluorescence and immunofluorescence histochemistry

The stain pontamine sky blue (PSB) has been shown to reduce background autofluorescence in catecholamine fluorescence and immunofluorescence histochemical preparations. Using PSB as a counterstain on whole-mount stretch preparations of human mesenteric blood vessels, a medium dense noradrenergic nerve plexus is clearly revealed, which previously had been only partially visible because of background autofluorescence. Image analysis of nerve densities in whole-mount stretch preparations of guinea-pig arteries containing noradrenergic, substance P-, and vasoactive intestinal polypeptide (VIP)-positive nerve plexuses shows that PSB staining does not alter the specific neuronal fluorescence and that it improves image definition.     

Connectivity and the development of population genetic structure in Indo‐West Pacific coral reef communities

Aim To identify connectivity patterns among coral reefs of the Indo‐West Pacific. Projecting connectivity forward in time provides a framework for studying long‐term source–sink dynamics in the region, and makes it possible to evaluate the manner in which migration shapes population genetic structure at regional scales. This information is essential for addressing critical gaps in knowledge for conservation planning efforts in one of the most biologically diverse regions on earth. Location Coral reefs of the Indo‐West Pacific, ranging from 15° S to 30° N and 95° E to 140° E. Methods Individual‐based biophysical dispersal models were used in conjunction with matrix projection to identify the expected patterns of exchange between coral reefs over time. Results Present‐day oceanographic conditions lead to the transport of larvae from the South China Sea into the Coral Triangle region via the Sulu Sea, and from northern Papua New Guinea and the Solomon Islands via Halmahera. The directionality of the system leads to the expected accumulation of organisms from outlying areas into the Coral Triangle region over time, particularly in the vicinity of the Maluku Islands and eastern Sulawesi. Coral reefs in Papua New Guinea, the Sulu Archipelago and areas within the Philippines are expected to be areas of high diversity as well. Main conclusions Biophysical dispersal models, used in conjunction with matrix projection, provide an effective means of simulating connectivity structure across the Indo‐West Pacific and thereby evaluating the directionality of genetic diversity. Migration appears to have a significant influence on population genetic structure in the region. Based on present‐day ocean currents, coral reefs in the South China Sea, northern Papua New Guinea and the Solomon Islands are contributing to high levels of diversity in the Coral Triangle.     

Population structure in a common Caribbean coral-reef fish: implications for larval dispersal and early life-history traits

Genetic population structure throughout the Caribbean Basin for one of the most common and widespread reef fish species, the bicolour damselfish Stegastes partitus was examined using microsatellite DNA markers. Spatial autocorrelation analysis showed a significant positive correlation between genetic and geographic distance (isolation by distance) over distances <1000 km, suggesting that populations are connected genetically but probably not demographically, i.e. over shorter time scales. A difference in spatial patterns of populations in the eastern v. the western Caribbean also raises the probability of an important role for meso-scale oceanographic features and landscape complexity within the same species. A comparison of S. partitus population structure and life-history traits with those of two other species of Caribbean reef fish studied earlier showed the findings to be concordant with a common hypothesis that shorter pelagic larval dispersal periods are associated with smaller larval dispersal scales.     

Small‐scale demographic variation in the stoplight parrotfish Sparisoma viride

Age‐based analysis of the stoplight parrotfish Sparisoma viride was used to examine whether observed differences in their abundance and size structure among reefs in a cross‐shelf portion of the upper Florida Keys could be explained by variation in demographic rates. Annual and daily sagittal otolith increments were enumerated for 176 individuals collected from replicates of reefs in two strata, inshore and offshore reefs (2–6 m depth). von Bertalanffy growth functions fitted to size‐at‐age plots for each site were similar between reefs within each stratum (inshore and offshore), but differed between strata. Sparisoma viride on offshore reefs attained greater average standard length (L_S) at age, greater mean asymptotic size and were longer lived than fish from inshore reefs. Fish on inshore reefs attained only half the maximum age observed on offshore reefs (4 v. 8 years, respectively). No terminal phase fish >4 years of age were found on either reef type. Estimates of mortality rates from age‐frequency data of collected fish revealed higher mortality on inshore reefs. Demographic variables obtained in this study were similar to published values for S. viride from Caribbean reefs but differed significantly from published values from reefs at a similar latitude (Bahamas), reflecting high demographic plasticity on both local and regional scales.     

Discovery of azabenzimidazole derivatives as potent, selective inhibitors of TBK1/IKKε kinases

The design, synthesis and biological evaluation of a series of azabenzimidazole derivatives as TBK1/IKKε kinase inhibitors are described. Starting from a lead compound 1a, iterative design and SAR exploitation of the scaffold led to analogues with nM enzyme potencies against TBK1/IKKε. These compounds also exhibited excellent cellular activity against TBK1. Further structure-based design to improve selectivity over CDK2 and Aurora B resulted in compounds such as 5b-e. These probe compounds will facilitate study of the complex cancer biology of TBK1 and IKKε.