Evolutionary relationships among the male and female mitochondrial DNA lineages in the Mytilus edulis species complex

A novel form of mitochondrial DNA (mtDNA) inheritance has previously been documented for the blue mussel (Mytilus edulis). Female mussels inherit their mtDNA solely from their mother while males inherit mtDNA from both their mother and their father. In males, the paternal mtDNA is preferentially amplified so that the male gonad is highly enriched for the paternal mtDNA that is then transmitted from fathers to sons. We demonstrate that this mode of mtDNA inheritance also operates in the closely related species M. galloprovincialis and M. trossulus. The evolutionary relationship between the male and female mtDNA lineages is estimated by phylogenetic analysis of 455 nucleotides from the large subunit ribosomal RNA gene. We have found that the male and female lineages are highly divergent; the divergence of these lineages began prior to the speciation of the three species of blue mussels. Further, the separation between the male and female lineages is estimated to have occurred between 5.3 and 5.7 MYA.      

BioTRIZ Suggests Radiative Cooling of Buildings Can Be Done Passively by Changing the Structure of Roof Insulation to Let Longwave Infrared Pass

This paper demonstrates the application of a design tool called BioTRIZ. Its developers claim that it can be used to access biological strategies for solving engineering problems. Our aim is to design a roof for hot climates that gets free cooling through radiant coupling with the sky. The insulation in a standard roof stops the sun and convection from warming the thermal mass. But it also restricts the mass＇s longwave view of the cool sky. Different solutions to this conflict are offered by BioTRIZ. The chosen solution is to replace the standard insulation component with an open cell honeycomb. The vertical cells would allow longwave radiation to pass, while arresting convection. The solutions offered by BioTRIZ＇s technological counterpart include no such changes in structure. It is estimated that the thermal mass in the biomimetic roof would remain on average 4.5℃ cooler than in a standard roof over a year in Riyadh, Saudi Arabia.     

Efficient Salmonella entry requires activity cycles of host ADF and cofilin

Entry of Salmonella into mammalian cells is strictly dependent on the reorganization of actin cytoskeleton induced by a panel of Salmonella type III secreted proteins. Although several factors have been identified to be responsible for inducing the actin polymerization and stability, little is known about how the actin depolymerization contributes to Salmonella-induced actin rearrangements. We report here that activity cycles of host actin depolymerizing factor (ADF and cofilin) are modulated by Salmonella during bacterial entry. Efficient Salmonella internalization involves an initial dephosphorylation of ADF and cofilin followed by phosphorylation, suggesting that ADF and cofilin activities are increased briefly. Expression of a kinase dead form of an ADF/cofilin kinase (LIM kinase 1) or a catalytically inactive ADF/cofilin phosphatase (Slingshot), but not constitutively active LIM kinase 1 or wild-type Slingshot, resulted in decreased invasion. These data suggest that ADF/cofilin activities play a key role in the actin polymerization/depolymerization process induced by Salmonella. The activation of ADF/cofilin is brief and has to be reversed to facilitate efficient bacterial entry. Surprisingly, co-expression of constitutive active ADF and cofilin prevented efficient Salmonella entry, whereas expression of either one alone had no effect. We propose that ADF and cofilin actin-dynamizing activities and their activity cycling via phosphorylation are required for efficient Salmonella internalization.     

Ionenkanalerkrankungen des Gehirns – monogene Migräneformen

As opposed to the common, genetically complex types of migraine, there are a few rare monogenic migraine variants. The prototype is familial hemiplegic migraine (FHM), a severe subtype of migraine with aura, for which three causative genes (FHM1–3), all of which are involved in ion translocation in the CNS, have been identified. This review summarizes the current knowledge about the clinical symptomatology, (differential) diagnosis, treatment, genetics, and pathophysiology of FHM. Clinically and genetically overlapping disorders, such as episodic ataxia type 2 (EA-2), spinocerebellar ataxia type 6 (SCA-6) and alternating hemiplegia of childhood (AHC) are briefly discussed, and novel genes which have been occasionally associated with HM or migraine are critically evaluated. Finally, monogenic (vascular) syndromes, in which migraine is part of the phenotypic spectrum, are discussed.     

Expression of the SM-20 Gene Promotes Death in Nerve Growth Factor-Dependent Sympathetic Neurons

Sympathetic neurons undergo apoptosis when deprived of nerve growth factor (NGF). Inhibitors of RNA or protein synthesis block this death, suggesting that gene expression is important for apoptosis in this system. We have identified SM-20 as a new gene that increases in expression in sympathetic neurons after NGF withdrawal. Expression of SM-20 also increases during neuronal death caused by cytosine arabinoside or the phosphatidylinositol 3-kinase inhibitor LY294002. In addition, SM-20 protein synthesis is elevated in NGF-deprived neurons compared with neurons maintained with NGF. Importantly, expression of SM-20 in sympathetic neurons causes cell death in the presence of NGF. These results suggest that SM-20 may function to regulate cell death in neurons.     

The innervation of the uterus in Salamandra salamandra (L.) (Amphibia,Urodela)

The innervation of the uterus in the ovoviviparous urodele Salamandra salamandra was studied. In whole mount preparations of the thin-walled uterus of pregnant females, a dense adrenergic network was demonstrated using a modified glyoxylic acid fluorescence technique. Based on vesicle type and cytochemical reactivity after chromate/dichromate fixation for electron microscopy at least two types of neural process were distinguished and classified as adrenergic and cholinergic. Both types are preferentially situated above or between the smooth muscles of the uterine tissue. Adjacent to the muscles in the walls of arterioles mainly adrenergic fibers are seen. Using high performance liquid chromatography with electrochemical detection in tissue homogenates of uterus a considerable amount of noradrenaline could be identified. The significance of the dense innervation is discussed with respect to the function of the uterus during pregnancy and birth.     

Therapie mitochondrialer Erkrankungen

Although there have been major advances in understanding the pathogenesis of mitochondrial disorders, current treatment is largely supportive and there is still no cure. A variety of pharmacological agents, vitamins and cofactors, dietary modifications and interventions are under investigation, including attempts to bypass blocks in the respiratory chain, antioxidative effects, supplementation of deficiencies of specific compounds or the removal of noxious metabolites. There is currently no clear evidence supporting the use of any of these interventions. However, replacement of deficient metabolites or elimination of toxic molecules might be beneficial in specific disorders. Moreover, current data suggest that idebenone might be useful in Leber??s hereditary optic neuropathy (LHON). Only few randomized controlled trials had been conducted to date, and future controlled trials are strongly needed to establish the role of therapeutic approaches in homogeneous study populations. Gene therapy is a challenge, but promising experimental approaches are being pursued.     

Heredit?re Fiebersyndrome

Familial Mediterranean fever (FMF), mevalonate kinase deficiency (MKD), and tumour necrosis factor (TNF) receptor-1-associated periodic syndrome (TRAPS) are monogenic disorders included under the term??hereditary fever syndromes??. These diseases are characterized by recurrent episodes of fever and inflammation and arise from mutations of genes regulating the innate immune system. The present review describes the clinical and genetic spectrum of hereditary fever syndromes, which are of importance for genetic counseling.