Ultrastructural localization of sulfated and unsulfated keratan sulfate in normal and macular corneal dystrophy type I

Keratan sulfate (KS) proteoglycans are of importance for the maintenance of corneal transparency as evidenced in the condition macular corneal dystrophy type I (MCD I), a disorder involving the absence of KS sulfation, in which the cornea becomes opaque. In this transmission electron microscope study quantitative immuno- and histochemical methods have been used to examine a normal and MCD I cornea. The monoclonal antibody, 5-D-4, has been used to localize sulfated KS and the lectin Erythrina cristagalli agglutinin (ECA) to localize poly N -acetyllactosamine (unsulfated KS). In normal cornea high levels of sulfated KS were detected in the stroma, Bowman's layer, and Descemet's membrane and low levels in the keratocytes, epithelium and endothelium. Furthermore, in normal cornea, negligible levels of labeling were found for N -acetyllactosamine (unsulfated KS). In the MCD I cornea sulfated KS was not detected anywhere, but a specific distribution of N -acetyllactosamine (unsulfated KS) was evident: deposits found in the stroma, keratocytes, and endothelium labeled heavily as did the disrupted posterior region of Descemet's membrane. However, the actual cytoplasm of cells and the undisrupted regions of stroma revealed low levels of labeling. In conclusion, little or no unsulfated KS is present in normal cornea, but in MCD I cornea the abnormal unsulfated KS was localized in deposits and did not associate with the collagen fibrils of the corneal stroma. This study has also shown that ECA is an effective probe for unsulfated KS.     

Fiji’s largest marine reserve benefits reef sharks

To provide more information about whether sharks benefit from no-take marine reserves, we quantified the relative abundance and biomass of reef sharks inside and outside of Namena, Fiji’s largest reserve (60.6 km²). Using stereo baited remote underwater video systems (stereo-BRUVs), we found that the abundance and biomass of sharks was approximately two and four times greater in shallow and deep locations, respectively, within the Namena reserve compared to adjacent fished areas. The greater abundance and biomass of reef sharks inside Namena is likely a result of greater prey availability rather than protection from fishing. This study demonstrates that marine reserves can benefit sharks.     

ChIA-PET tool for comprehensive chromatin interaction analysis with paired-end tag sequencing

Chromatin interaction analysis with paired-end tag sequencing (ChIA-PET) is a new technology to study genome-wide long-range chromatin interactions bound by protein factors. Here we present ChIA-PET Tool, a software package for automatic processing of ChIA-PET sequence data, including linker filtering, mapping tags to reference genomes, identifying protein binding sites and chromatin interactions, and displaying the results on a graphical genome browser. ChIA-PET Tool is fast, accurate, comprehensive, user-friendly, and open source (available at http://chiapet.gis.a-star.edu.sg).