Genetic diversity and structure of blue whales (Balaenoptera musculus) in Australian feeding aggregations

The worldwide distribution of blue whales (Balaenoptera musculus) has not prevented this species from becoming endangered due to twentieth century whaling. In Australia there are two known feeding aggregations of blue whales, which most likely are the pygmy subspecies (B. m. brevicauda). It is unknown whether individuals from these feeding aggregations belong to one breeding stock, or multiple breeding stocks that either share or occupy separate feeding grounds. This was investigated using ten microsatellite loci and mitochondrial DNA control region sequences (N = 110). Both sets of markers revealed no significant genetic structure, suggesting that these whales are likely to belong to the same breeding stock.     

Control of carbohydrate metabolism in an anoxia-tolerant nervous system

Anoxia-tolerant animal models are crucial to understand protective mechanisms during low oxygen excursions. As glycogen is the main fermentable fuel supporting energy production during oxygen tension reduction, understanding glycogen metabolism can provide important insights about processes involved in anoxia survival. In this report we studied carbohydrate metabolism regulation in the central nervous system (CNS) of an anoxia-tolerant land snail during experimental anoxia exposure and subsequent reoxygenation. Glucose uptake, glycogen synthesis from glucose, and the key enzymes of glycogen metabolism, glycogen synthase (GS) and glycogen phosphorylase (GP), were analyzed. When exposed to anoxia, the nervous ganglia of the snail achieved a sustained glucose uptake and glycogen synthesis levels, which seems important to maintain neural homeostasis. However, the activities of GS and GP were reduced, indicating a possible metabolic depression in the CNS. During the aerobic recovery period, the enzyme activities returned to basal values. The possible strategies used by Megalobulimus abbreviatus CNS to survive anoxia are discussed.     

Aqueous-phase quantitative NMR determination of amino acid enantiomer ratio by 13C-NMR using chiral neodymium shift reagent

A neodymium-(S)-PDTA (PDTA = N,N,N′,N′-tetrakis[(hydroxycarbonyl)methyl]-1,2-diaminopropane) complex was found exceptionally useful in the quantitative determination of enantiomer ratios of water-soluble natural amino acids by ¹³C-NMR. The method is demonstrated on mixtures of l- and d-enantiomers of various amino acids. The interactions of the chiral shift reagent with the amino acid molecules were rationalized by molecular orbital calculations.     

The caspase‐cleaved form of LYN mediates a psoriasis‐like inflammatory syndrome in mice

We showed previously that Lyn is a substrate for caspases, a family of cysteine proteases, involved in the regulation of apoptosis and inflammation. Here, we report that expression of the caspase‐cleaved form of Lyn (LynΔN), in mice, mediates a chronic inflammatory syndrome resembling human psoriasis. Genetic ablation of TNF receptor 1 in a LynΔN background rescues a normal phenotype, indicating that LynΔN mice phenotype is TNF‐α‐dependent. The predominant role of T cells in the disease occurring in LynΔN mice was highlighted by the distinct improvement of LynΔN mice phenotype in a Rag1‐deficient background. Using pan‐genomic profiling, we also established that LynΔN mice show an increased expression of STAT‐3 and inhibitory members of the NFκB pathway. Accordingly, LynΔN alters NFκB activity underlying a link between inhibition of NFκB and LynΔN mice phenotype. Finally, analysis of Lyn expression in human skin biopsies of psoriatic patients led to the detection of Lyn cleavage product whose expression correlates with the activation of caspase 1. Our data identify a new role for Lyn as a regulator of psoriasis through its cleavage by caspases.