Isolating the influence of ontogeny helps predict island-wide variability in fish otolith chemistry

Reviews in Fish Biology and Fisheries - For marine fishes of commercial interest, defining how individuals vary in certain attributes, through ontogeny, and across space and time, can help expose...     

Two different mechanisms in patients with venous thrombosis and defective fibrinolysis: low concentration of plasminogen activator or increased concentration of plasminogen activator inhibitor.

Fibrinolytic components after venous occlusion and concentrations of tissue plasminogen activator inhibitor were studied in 100 consecutive patients with confirmed recurrent deep vein thrombosis or pulmonary embolism. After 20 minutes of venous occlusion the fibrinolytic response was decreased in 33 patients, as measured both amidolytically with S-2251 and on fibrin plates. Two different mechanisms responsible for the poor fibrinolytic response could be distinguished. Twenty two of the patients in whom the response was poor released normal amounts of tissue plasminogen activator antigen, as assayed by immunoradiometric assay, but had appreciably increased concentrations of tissue plasminogen activator inhibitor. The 11 other patients in whom the response was poor had both low tissue plasminogen activator activities and low tissue plasminogen activator antigen concentrations but normal concentrations of tissue plasminogen activator inhibitor. The results show not only that defective synthesis or release of tissue plasminogen activator may be important in the pathogenesis of venous thrombosis but also that a large group of patients with thrombosis have an increased concentration of the inhibitor to tissue plasminogen activator.     

Genome scans and elusive candidate genes: detecting the variation that matters for speciation

Next‐generation sequencing is providing us with vast amounts of genetic data, yet we are currently struggling in our attempts to make sense of them. In particular, it has proven difficult to link phenotypic divergence and speciation to genome level divergence. In the current issue of Molecular Ecology, Ruegg et al. ( 2014 ) present new empirical results from two closely related bird taxa. They use a promising approach combining genome scan and candidate gene analysis. Their results suggest that we may have been looking in vain for candidate speciation genes by focusing only on genes found within genomic islands of divergence. This is because genes important in divergence and speciation may not be detected by genome scans and because features of the genomic architecture per se may have a large effect on the pattern of genome divergence.     

Platelet vinculin: a substrate of activated factor XIII

In addition to plasma, Factor XIII of blood coagulation (FXIII) is also present in the cytosol of platelets, monocytes and macrophages. However, its intracellular function has not yet been revealed. Activated Factor XIII (FXIIIa) is a transglutaminase (protein-glutamine: amine gamma-glutamyltransferase, EC 2.3.2.13) of highly restricted substrate specificity with only a few known protein substrates. In this report, we showed that FXIIIa can link dansylcadaverine, radiolabelled histamine and putrescine to vinculin. Quantitative determinations revealed that in the vinculin molecule a single glutamine residue can serve as acyl donor for the incorporation of small-molecular-weight amines. Vinculin could not be crosslinked to another vinculin molecule. It could be covalently bound, however, to fibrinogen, which indicates that the acyl donor glutamine residue can be engaged in an epsilon-(gamma-glutamyl)lysyl crosslink formation. Since it has been shown that platelet actin and myosin, two main components of cytoskeleton, are also substrates for FXIIIa, and that vinculin is associated to the cytoskeleton during platelet activation, the involvement of FXIII in the stabilization of cytoskeleton at certain phases of cellular function is a likely possibility.     

Factors influencing the stability of acid-precipitated polyvalent Bordetella pertussis bulk suspensions.

According to the statistical analysis of the potency values of acid precipitated polyvalent bulk suspensions of Bordetella pertussis, the potency of suspensions decreased below 8 IU/30 IOU during storage for 5 to 9.8 years. The average annual decrease over a 13-year period was 2.03 IU/30 IOU. The periodicity in the decrease of potency values was assumed to be connected with changes in the quality of the casein hydrolysate ingredient of the medium. Periodic functions employed to approach potency values with limits of 1 SD falling within the range of 64--156% indicated that the potency decreased below 8 IU/30 IOU after 9 years.     

Organization and expression of mouse Hox3 cluster genes

Summary The three yolk protein genes (yp) of Drosophila melanogaster are transcribed in a sex- and tissue-limited fashion. We have searched for cis-regulatory sequences in regions flanking yp1 and yp2 to identify the elements that confer female-specific expression in the fat body. One such 127 by element has previously been identified in this region. We show here the existence of two additional regions which confer female fat body-specific expression on an Adh reporter gene and on the native yp2 gene, respectively. This suggests some redundancy in the regulation of expression of the yp genes. Computer searches for putative binding sites for the DSX protein, which regulates sex-specific expression of the yp genes, revealed several such sites in our constructs. However, the significance of these is unclear since many such sites also occur in genes which one would not expect to be regulated in a sex-specific manner (e.g. Adh, Actin 5C). We suggest that DSX acts in concert with other proteins to mediate sex- and tissue-specific expression of the yp genes.