Dead Shrimp Blues: A Global Assessment of Extinction Risk in Freshwater Shrimps (Crustacea: Decapoda: Caridea)

We present the first global assessment of extinction risk for a major group of freshwater invertebrates, caridean shrimps. The risk of extinction for all 763 species was assessed using the IUCN Red List criteria that include geographic ranges, habitats, ecology and past and present threats. The Indo-Malayan region holds over half of global species diversity, with a peak in Indo-China and southern China. Shrimps primarily inhabit flowing water; however, a significant subterranean component is present, which is more threatened than the surface fauna. Two species are extinct with a further 10 possibly extinct, and almost one third of species are either threatened or Near Threatened (NT). Threats to freshwater shrimps include agricultural and urban pollution impact over two-thirds of threatened and NT species. Invasive species and climate change have the greatest overall impact of all threats (based on combined timing, scope and severity of threats).     

Mapping-by-Sequencing Identifies HvPHYTOCHROME C as a Candidate Gene for the early maturity 5 Locus Modulating the Circadian Clock and Photoperiodic Flowering in Barley

Phytochromes play an important role in light signaling and photoperiodic control of flowering time in plants. Here we propose that the red/far-red light photoreceptor HvPHYTOCHROME C (HvPHYC), carrying a mutation in a conserved region of the GAF domain, is a candidate underlying the early maturity 5 locus in barley (Hordeum vulgare L.). We fine mapped the gene using a mapping-by-sequencing approach applied on the whole-exome capture data from bulked early flowering segregants derived from a backcross of the Bowman(eam5) introgression line. We demonstrate that eam5 disrupts circadian expression of clock genes. Moreover, it interacts with the major photoperiod response gene Ppd-H1 to accelerate flowering under noninductive short days. Our results suggest that HvPHYC participates in transmission of light signals to the circadian clock and thus modulates light-dependent processes such as photoperiodic regulation of flowering.     

Analyzing protein–protein interactions in the post-interactomic era. Are we ready for the endgame?

Mapping protein–protein interactions in genome-wide scales revealed thousands of novel binding partners in each of the explored model organisms. Organizing these hits in comprehensive ways is becoming increasingly important for systems biology approaches to understand complex cellular processes and diseases. However, proteome wide interaction techniques and their resulting global networks are not revealing the topologies of networks that are truly operating in the cell. In this short review I will discuss which prerequisites have to be fulfilled and which experimental methods might be practicable to translate primary protein interaction data into network presentations that help in understanding cellular processes.     

Sources of phenotypic variance in egg and larval traits in a marine invertebrate

Contrary to many separate sex systems, the evolutionary ecology of polyandry in simultaneous hermaphrodites, and in particular in those with internal fertilization, has received little attention. Recent studies on the promiscuous gastropod Chelidonura sandrana showed that offspring size, an important determinant of offspring performance in many marine invertebrates, varies with the number of different mating partners. However, the source of this differential allocation by mothers remained unclear. Using a quantitative genetic model, we here tested for parental effects on offspring size and the importance of ‘good gene’ effects on early life history traits. Our analysis revealed no significant sire but strong dam effects for all investigated traits. Moreover, embryo viability tended to increase with egg capsule volume, thus linking offspring size with offspring performance. Our findings suggest that in C. sandrana (1) differential allocation is a maternal effect in response to the number of different partners, and that (2) additive genetic variance is of negligible importance in early life history traits.     

The involvement of the left motor cortex in learning of a novel action word lexicon

Current theoretical positions assume that action-related word meanings are established by functional connections between perisylvian language areas and the motor cortex (MC) according to Hebb's associative learning principle. To test this assumption, we probed the functional relevance of the left MC for learning of a novel action word vocabulary by disturbing neural plasticity in the MC with transcranial direct current stimulation (tDCS). In combination with tDCS, subjects learned a novel vocabulary of 76 concrete, body-related actions by means of an associative learning paradigm. Compared with a control condition with "sham" stimulation, cathodal tDCS reduced success rates in vocabulary acquisition, as shown by tests of novel action word translation into the native language. The analysis of learning behavior revealed a specific effect of cathodal tDCS on the ability to associatively couple actions with novel words. In contrast, we did not find these effects in control experiments, when tDCS was applied to the prefrontal cortex or when subjects learned object-related words. The present study lends direct evidence to the proposition that the left MC is causally involved in the acquisition of novel action-related words.     

N‐cadherin is dispensable for pancreas development but required for β‐cell granule turnover

The cadherin family of cell adhesion molecules mediates adhesive interactions that are required for the formation and maintenance of tissues. Previously, we demonstrated that N‐cadherin, which is required for numerous morphogenetic processes, is expressed in the pancreatic epithelium at E9.5, but later becomes restricted to endocrine aggregates in mice. To study the role of N‐cadherin during pancreas formation and function we generated a tissue‐specific knockout of N‐cadherin in the early pancreatic epithelium by inter‐crossing N‐cadherin‐floxed mice with Pdx1Cre mice. Analysis of pancreas‐specific ablation of N‐cadherin demonstrates that N‐cadherin is dispensable for pancreatic development, but required for β‐cell granule turnover. The number of insulin secretory granules is significantly reduced in N‐cadherin‐deficient β‐cells, and as a consequence insulin secretion is decreased. genesis 48:374–381, 2010. © 2010 Wiley‐Liss, Inc.     

Method of intracranial pressure monitoring and cerebrospinal fluid sampling in swine

Cerebral oedema and encephalopathy have been noted to occur frequently in patients severely ill or dying after trauma, ischaemia, infections or even metabolic disorders. The objective of the present study was to establish continuous monitoring of the intracranial pressure (ICP) and sampling of cerebrospinal fluid (CSF) for further investigations in swine. ICP monitoring was established in eight pigs by using a ventricular drainage system, implemented after paramedian trepanation of the os frontale. CSF and serum samples were taken for measurement of the levels of glucose and protein. Operating time was 21+/-8 min for the trepanation until ICP monitoring was performed. No complications occurred during surgery. Continuous monitoring of ICP and CSF sampling was easy to perform, and without any side-effects in any animal. At autopsy, no iatrogenic lesions were found and monitoring catheters were still in place. For several types of research requiring ICP monitoring and sampling of CSF, this method can be used successfully.     

The gradual onset brain death model: a relevant model to study organ donation and its consequences on the outcome after transplantation

Organs used for transplantation are usually derived from heart-beating brain dead donors. However, brain death is known to have negative effects on donor organ quality, previously studied using a difficult to control sudden onset experimental model. We have now developed a reproducible gradual onset brain death model in rats without requiring inotropic support. Fisher inbred rats weighing 260-300 g were used. Brain death was induced by a gradual inflation of a subdurally placed balloon catheter. During induction and the period following brain death, the animals were mechanically ventilated and blood pressure was continuously monitored. The blood pressure registration showed a characteristic pattern during brain death induction, in which a decrease in blood pressure, a hypotensive period in which the Cushing response occurred, and a sharp peak were consistent findings. After brain death was induced, blood pressure was maintained at normotensive levels up to 4 h. After the experiments, neuropathological evaluation of the brain located haemorrhagic cerebral parenchyma, and immunocytochemistry of liver tissue revealed a significant influx of polymorph nuclear cells, as was previously observed as well. This improved model allows the study of brain death on donor organ quality without the use of inotropic support.