Extraction of pigments and fatty acids from the green alga Scenedesmus obliquus (Chlorophyceae)

In this paper, the efficiency of pigment and fatty acid extraction from resistant algae using Scenedesmus obliquus as an example was examined. We found that adding quartz sand and solvent to freeze-dried algal material and subsequent extraction in an ultrasound bath for 90min at –4°C resulted in excellent extraction of these compounds. This extraction method was compared with a method regularly used for extraction of fatty acids and pigments, i.e. addition of solvents to algal material with subsequent incubation. Our extraction using the ultrasound and sand method was about twice as efficient as this method for both pigments and fatty acids. The ultrasound method is simple, extracts over 90% of the different substances in one step and conserves the relationships of pigments and fatty acids. In addition, no alteration- or breakdown products were observed with the new method. Thus, this method allows accurate quantitative extraction of both pigments and fatty acids from Scenedesmus obliquus and other algae. The method was also been found to be as effective for Cryptomonas erosa (Cryptophyceae), Cyclotella meneghiniana (Bacillariophyceae), Microcystis aeruginosa (Cyanophyceae), and Staurastrum paradoxum (Chlorophyceae, Desmidiaceae) and is thus applicable to a wide spectrum of algae.     

Ecological long-term research at Helgoland (German Bight,North Sea): retrospect and prospect—an introduction

This paper summarizes and evaluates ecological long-term observations at the island of Helgoland (German Bight, North Sea). It is an introduction to a series of seven contributions to an issue of Helgoland Marine Research (vol. 58, no. 4) dealing with observations on the physico-chemical environment and the local biota (pelagic bacteria, phytoplankton, zooplankton, macroalgae, macrozoobenthos). More than 150 years of research at Helgoland (at the Biologische Anstalt Helgoland, BAH, since 1892), and particularly the Helgoland Roads time-series which started in 1962, has provided a multitude of data which represents a valuable basis for analysing past changes, evaluating the present status and predicting future changes in ecosystem parameters. Predicting the consequences of the recent rapid ecological change on regional and global scales requires increased efforts of focus on long-term ecological observations. Future efforts in this field will rely on the application of innovative advanced technology and on the concerted activities of a large number of institutions which only collectively can establish the large-scale patterns of temporal and spatial change in ecosystem functions.     

A genomewide scan for loci predisposing to type 2 diabetes in a U.K. population (the Diabetes UK Warren 2 Repository): analysis of 573 pedigrees provides independent replication of a susceptibility locus on chromosome 1q

Improved molecular understanding of the pathogenesis of type 2 diabetes is essential if current therapeutic and preventative options are to be extended. To identify diabetes-susceptibility genes, we have completed a primary (418-marker, 9-cM) autosomal-genome scan of 743 sib pairs (573 pedigrees) with type 2 diabetes who are from the Diabetes UK Warren 2 repository. Nonparametric linkage analysis of the entire data set identified seven regions showing evidence for linkage, with allele-sharing LOD scores > or =1.18 (P< or =.01). The strongest evidence was seen on chromosomes 8p21-22 (near D8S258 [LOD score 2.55]) and 10q23.3 (near D10S1765 [LOD score 1.99]), both coinciding with regions identified in previous scans in European subjects. This was also true of two lesser regions identified, on chromosomes 5q13 (D5S647 [LOD score 1.22] and 5q32 (D5S436 [LOD score 1.22]). Loci on 7p15.3 (LOD score 1.31) and 8q24.2 (LOD score 1.41) are novel. The final region showing evidence for linkage, on chromosome 1q24-25 (near D1S218 [LOD score 1.50]), colocalizes with evidence for linkage to diabetes found in Utah, French, and Pima families and in the GK rat. After dense-map genotyping (mean marker spacing 4.4 cM), evidence for linkage to this region increased to a LOD score of 1.98. Conditional analyses revealed nominally significant interactions between this locus and the regions on chromosomes 10q23.3 (P=.01) and 5q32 (P=.02). These data, derived from one of the largest genome scans undertaken in this condition, confirm that individual susceptibility-gene effects for type 2 diabetes are likely to be modest in size. Taken with genome scans in other populations, they provide both replication of previous evidence indicating the presence of a diabetes-susceptibility locus on chromosome 1q24-25 and support for the existence of additional loci on chromosomes 5, 8, and 10. These data should accelerate positional cloning efforts in these regions of interest.     

Allozyme variation and conservation of the Tasmanian endemics, Eucalyptus risdonii, E. tenuiramis and E. coccifera

The rare Tasmanian endemic Eucalyptus risdonii is thought tohave arisen as a result of small, heterochronic changes to the genome ofits more widespread sister species, E. tenuiramis. Previousmorphological studies have shown that genetic differentiation betweenpopulations of E. risdonii and southern E. tenuiramisis continuous and much smaller than the separation between the southernand northern morphotypes of E. tenuiramis. However,morphological traits may be influenced by selection, possibly leading toconvergence, requiring an independent measure of genetic variation. Westudied allozyme frequency variation in E. risdonii, southernE. tenuiramis (parapatric with E. risdonii), northernE. tenuiramis (disjunct from southern populations), and E.coccifera (as an outgroup). Each morphotype had a level of geneticdiversity close to the average reported in ten other eucalypt specieswith similar distributions but the coefficients of populationdifferentiation within morphotypes were lower than in most othereucalypt species. The overall difference between morphotypes wasextremely small, possibly as a result of recent and rapiddifferentiation, but may also be the result of gene flow from otherpeppermint taxa, including E. amygdalina and E.pulchella. Southern E. tenuiramis has greater geneticaffinity with E. risdonii than with northern E.tenuiramis which supports recent evolutionary divergence of E.risdonii. In this study we have shown that taxonomic units are notnecessarily aligned with an equitable partition of the gene pool andthat conservation units should be much broader than single taxa in orderto preserve evolutionary processes.     

Carbonic Anhydrase-8 Regulates Inflammatory Pain by Inhibiting the ITPR1-Cytosolic Free Calcium Pathway

Calcium dysregulation is causally linked with various forms of neuropathology including seizure disorders, multiple sclerosis, Huntington’s disease, Alzheimer’s, spinal cerebellar ataxia (SCA) and chronic pain. Carbonic anhydrase-8 (Car8) is an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1), which regulates intracellular calcium release fundamental to critical cellular functions including neuronal excitability, neurite outgrowth, neurotransmitter release, mitochondrial energy production and cell fate. In this report we test the hypothesis that Car8 regulation of ITPR1 and cytoplasmic free calcium release is critical to nociception and pain behaviors. We show Car8 null mutant mice (MT) exhibit mechanical allodynia and thermal hyperalgesia. Dorsal root ganglia (DRG) from MT also demonstrate increased steady-state ITPR1 phosphorylation (pITPR1) and cytoplasmic free calcium release. Overexpression of Car8 wildtype protein in MT nociceptors complements Car8 deficiency, down regulates pITPR1 and abolishes thermal and mechanical hypersensitivity. We also show that Car8 nociceptor overexpression alleviates chronic inflammatory pain. Finally, inflammation results in downregulation of DRG Car8 that is associated with increased pITPR1 expression relative to ITPR1, suggesting a possible mechanism of acute hypersensitivity. Our findings indicate Car8 regulates the ITPR1-cytosolic free calcium pathway that is critical to nociception, inflammatory pain and possibly other neuropathological states. Car8 and ITPR1 represent new therapeutic targets for chronic pain.     

Determination of reactive oxygen and nitrogen species in rat aorta using the dichlorofluorescein assay

A method for the determination of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in macroscopic sections of vessels has been developed on the basis of the dichlorofluorescein (DCF) assay. DCF was measured by fluorescence in extracts of vessels. The main artifact of the method is the oxidation of dichlorodihydrofluorescein (DCFH₂) which is released from vessels together with DCF during the extraction procedure. This problem was resolved by decreasing pH during the extraction. The optimal conditions and the time for aorta incubation with DCFH₂-DA and for the extraction of DCF from aorta have been determined. The ROS/RNS production in different aorta segments and the dependence of ROS/RNS production on rat age have been studied. It was shown that thoracic aorta sections produced the same amounts of ROS/RNS and the intermediate between the thoracic and the abdominal aorta part produced ROS and RNS by 14% more than the thoracic aorta. It was found that ROS/RNS production in aorta increases with rat age: the doubling time of ROS/RNS production rate is 113 days from birth.     

Gα<Subscript>16</Subscript> interacts with tetratricopeptide repeat 1 (TPR1) through its β3 region to activate Ras independently of phospholipase Cβ signaling

Background  

G protein-coupled receptors constitute the largest family of cell surface receptors in the mammalian genome. As the core of the G protein signal transduction machinery, the Gα subunits are required to interact with multiple partners. The GTP-bound active state of many Gα subunits can bind a multitude of effectors and regulatory proteins. Yet it remains unclear if the different proteins utilize distinct or common structural motifs on the Gα subunit for binding. Using Gα₁₆ as a model, we asked if its recently discovered adaptor protein tetratricopeptide repeat 1 (TPR1) binds to the same region as its canonical effector, phospholipase Cβ (PLCβ).