Systematics within Gyps vultures: a clade at risk

Background  

Populations of the Oriental White-backed Vulture (Gyps bengalensis) have declined by over 95% within the past decade. This decline is largely due to incidental consumption of the non-steroidal anti-inflammatory veterinary pharmaceutical diclofenac, commonly used to treat domestic livestock. The conservation status of other Gyps vultures in southern Asia is also of immediate concern, given the lack of knowledge regarding status of their populations and the continuing existence of taxonomic uncertainties. In this study, we assess phylogenetic relationships for all recognized species and the majority of subspecies within the genus Gyps. The continuing veterinary use of diclofenac is an unknown but potential risk to related species with similar feeding habits to Gyps bengalensis. Therefore, an accurate assessment of the phylogenetic relationships among Gyps vultures should aid in their conservation by clarifying taxonomic uncertainties, and enabling inference of their respective relatedness to susceptible G. bengalensis.     

Patterns of divergence during evolution of alpha 1-proteinase inhibitors in mammals

alpha 1-Proteinase inhibitor (alpha 1-PI), a member of the serine proteinase inhibitor superfamily, has a primary role in controlling neutrophil elastase activity within the mammalian circulation. Several studies have indicated that the reactive center region of alpha 1-PI, the amino acid sequence of which is critical to recognition of and binding to target proteinases, is highly divergent within and among species. This appears to be a consequence of accelerated rates of evolution that may have been driven by positive Darwinian selection. In order to examine this and other features of alpha 1-PI evolution in more detail, we have isolated and sequenced cDNAs representing alpha 1- PI mRNAs of the mouse species Mus saxicola and Mus minutoides and have compared these with a number of other mammalian alpha 1-PI mRNAs. Relative to other mammalian mRNAs, the extent of nonsynonymous substitution is generally high throughout the alpha 1-PI mRNA molecule, indicating greater overall rates of amino acid substitution. Within and among mouse species, the 5'-half of the mRNA, but not the 3'-half, has been homogenized by concerted evolution. Finally, the reactive center is under diversifying or positive Darwinian selection in murid rodents (rats, mice) and guinea pigs yet is under purifying selection in primates and artiodactyls. The significance of these findings to alpha 1-PI function and the possible selective forces driving evolution of serpins in general are discussed.      

Mitochondrial DNA polymorphisms in subterranean mole-rats of the Spalax ehrenbergi superspecies in Israel, and its peripheral isolates

Patterns of mitochondrial DNA (mtDNA) variation were examined in 133 mole-rats constituting all four chromosomal species (2n = 52, 2n = 54, 2n = 58, and 2n = 60) of the Spalax ehrenbergi superspecies in Israel, as well as the peripheral isolates of 2n = 60. In the main range of the complex, a total of 28 mtDNA haplotypes were found in 64 mole-rats, with most haplotypes being unique to either a single chromosomal species or population. mtDNA divergence increased from low to high diploid number in a north-to-south direction in Israel. Overall levels of mtDNA diversity were unexpectedly the highest in the 2n = 60, the youngest species of the complex. The mtDNA haplotypes can be separated into two major groups, 2n = 52-54 and 2n = 58-60, and a phylogenetic analysis for each group revealed evidence of a few haplotypes not sorted by diploid number. The overall patterns of mtDNA divergence seen within and among the four chromosomal species are consistent with the parapatric mode of speciation as suggested from previous studies of allozyme and DNA hybridization. In a separate data set the patterns of mtDNA variation were examined across the main geographic range and across peripheral semi-isolates and isolates of the 2n = 60 chromosomal species. Fifteen haplotypes were found in 69 mole-rats. High levels of mtDNA diversity characterized the main range, semi-isolated, and even some desert isolated populations. The peripheral isolates contain much mtDNA diversity, including novel haplotypes.      

The Role of Stress-Induced Changes of Homer1 Expression in Stress Susceptibility

Biochemistry (Moscow) - Stress negatively affects processes of synaptic plasticity and is a major risk factor of various psychopathologies such as depression and anxiety. HOMER1 is an important...     

The pathogenic potential of the combined action of chronic Opisthorchis felineus infection and repeated social defeat stress in C57BL/6 mice

Parasitic food-borne diseases and chronic social stress are frequent attributes of day-to-day human life. Therefore, our aim was to model the combined action of chronic Opisthorchis felineus infection and repeated social defeat stress in C57BL/6 mice. Histological examination of the liver revealed inflammation sites, pronounced periductal fibrosis, and cholangiofibrosis together with proliferation of bile ducts and hepatocyte dystrophy in the infected mice, especially in the stress-exposed ones. Simultaneously with liver pathology, we detected significant structural changes in the cerebral cortex. Immunohistochemical analysis of the hippocampus indicated the highest increase in numerical density of Iba 1-, IL-6-, iNOS-, and Arg1-positive cells in mice simultaneously subjected to the two adverse factors. The number of GFAP-positive cells rose during repeated social defeat stress, most strongly in the mice subjected to both infection and stress. Real-time PCR analysis showed that the expression of genes Aif1 and Il6 differed among the analysed brain regions (hippocampus, hypothalamus, and frontal cortex) and depended on the adverse factors applied. In addition, among the brain regions, there was no consistent increase or decrease in these parameters when the two adverse treatments were combined: (i) in the hippocampus, there was upregulation of Aif1 and no change in Il6 expression; (ii) in the hypothalamus, expression levels of Aif1 and Il6 were not different from controls; and (iii) in the frontal cortex, Aif1 expression did not change while Il6 expression increased. It can be concluded that a combination of two long-lasting adverse factors, O. felineus infection and repeated social defeat stress, worsens not only the hepatic but also brain state, as evidenced behaviorally by disturbances of the startle response in mice.     

Testing of the method for water microleakage detection from OH hydroxyl spectral lines at the L-2M stellarator

Results are presented from L-2M stellarator experiments on testing a possible method for detection of water microleakages in the cooling system of the first wall and vacuum chamber of ITER. The method consists in the spectroscopic detection of spectral lines of the OH hydroxyl, which forms via the dissociation of water molecules in plasma. Emission in the spectral band of 305–310 nm can be detected even at water leakage rates less than 10^?4 Pa m³/s. Chemical reactions between water and boron compounds on the vacuum chamber wall delay the detection of leakages up to ～2000 s. A similar phenomenon can be expected when a leakage will occur in ITER, where the materials suggested for the first wall (Be, Li) can also chemically react with water.     

Approach to Minimize Damage Resulting from Microelectrode Insertion into Neuron

Biophysics - Penetration of a microelectrode into the cell soma is one of the most vulnerable stages of the method intracellular recording. Traumatic neuronal activity after piercing the membrane...     

Whole Exome Sequencing Reveals Homozygous Mutations in RAI1, OTOF,and SLC26A4 Genes Associated with Nonsyndromic Hearing Loss in Altaian Families (South Siberia)

Hearing loss (HL) is one of the most common sensorineural disorders and several dozen genes contribute to its pathogenesis. Establishing a genetic diagnosis of HL is of great importance for clinical evaluation of deaf patients and for estimating recurrence risks for their families. Efforts to identify genes responsible for HL have been challenged by high genetic heterogeneity and different ethnic-specific prevalence of inherited deafness. Here we present the utility of whole exome sequencing (WES) for identifying candidate causal variants for previously unexplained nonsyndromic HL of seven patients from four unrelated Altaian families (the Altai Republic, South Siberia). The WES analysis revealed homozygous missense mutations in three genes associated with HL. Mutation c.2168A>G (SLC26A4) was found in one family, a novel mutation c.1111G>C (OTOF) was revealed in another family, and mutation c.5254G>A (RAI1) was found in two families. Sanger sequencing was applied for screening of identified variants in an ethnically diverse cohort of other patients with HL (n = 116) and in Altaian controls (n = 120). Identified variants were found only in patients of Altaian ethnicity (n = 93). Several lines of evidences support the association of homozygosity for discovered variants c.5254G>A (RAI1), c.1111C>G (OTOF), and c.2168A>G (SLC26A4) with HL in Altaian patients. Local prevalence of identified variants implies possible founder effect in significant number of HL cases in indigenous population of the Altai region. Notably, this is the first reported instance of patients with RAI1 missense mutation whose HL is not accompanied by specific traits typical for Smith-Magenis syndrome. Presumed association of RAI1 gene variant c.5254G>A with isolated HL needs to be proved by further experimental studies.