DIET OF WEDDELL SEALS LEPTONYCHOTES WEDDELLII AT VESTKAPP, EASTERN WEDDELL SEA (ANTARCTICA), IN RELATION TO LOCAL FOOD SUPPLY

Thirteen Weddell seals ( Leptonychotes weddellii ) were collected at Vestkapp, eastern Weddell Sea coast, in austral spring 1986. All stomachs contained partially digested food. The mean wet weight of stomach contents was 7.5 kg, 3.3% of the. mean body weight of the collected seals. Twelve fish species and three cephalopod species were identified from 372 left otoliths and 25 lower beaks, representing 58.4% of 679 total prey items obtained. Composition by number of total prey was: Chionodraco myersi (15.8%), Trematomus eulepidotus (10.0%), Pagetopsis maculatus (9.7%), Racovitzia glacialis (9.6%) and Cryodraco antarcticus (4.1%). Otoliths of the seven other fish species and beaks of the three cephalopod species together represented 9.1% of total prey numbers. The pooled wet weights calculated from 13 prey species (regressions for two octopod species were not available) amounted to 43.5 kg food mass and represented 44.7% of the combined food mass in all stomachs. Composition by mass was: C. myersi (44.5%), T. eulepidotus (19.8%), squid Psychroteuthis glacialis (8.5%), P. maculates (7.9%), C. antarcticus (7.1%) and R. glacialis (6.2%). The remaining 7 fish species together represented 5.8% by mass. Temporal variation in food availability was apparent. Midwater fish Pleuragramma antarcticum was the staple food of Weddell seals from the same area during the 1985 summer, whereas it was absent in the samples taken in spring 1986. Estimates of fish biomass from net hauls demonstrate a highly variable availability of pelagic food resources for top predators in the Vestkapp area.     

Mannose binding lectin plays a crucial role in innate immunity against yeast by enhanced complement activation and enhanced uptake of polymorphonuclear cells

Background  

Mannose binding lectin (MBL) is an important host defence protein against opportunistic fungal pathogens. This carbohydrate-binding protein, an opsonin and lectin pathway activator, binds through multiple lectin domains to the repeating sugar arrays displayed on the surface of a wide range of clinically relevant microbial species. We investigated the contribution of MBL to antifungal innate immunity towards C. parapsilosis in vitro.     

S-formylglutathione hydrolase of Paracoccus denitrificans is homologous to human esterase D: a universal pathway for formaldehyde detoxification?

Downstream of flhA, the Paracoccus denitrificans gene encoding glutathione-dependent formaldehyde dehydrogenase, an open reading frame was identified and called fghA. The gene product of fghA showed appreciable similarity with human esterase D and with the deduced amino acid sequences of open reading frames found in Escherichia coli, Haemophilus influenzae, and Saccharomyces cerevisiae. Mutating fghA strongly reduced S-formylglutathione hydrolase activity. The mutant was unable to grow on methanol and methylamine, indicating that the enzyme is essential for methylotrophic growth. S-Formylglutathione hydrolase appears to be part of a formaldehyde detoxification pathway that is universal in nature.