Environmental margin and island evolution in Middle Eastern populations of the Egyptian fruit bat.

Here, we present a study of the population genetic architecture and microevolution of the Egyptian fruit bat (Rousettus aegyptiacus) at the environmental margins in the Middle East using mitochondrial sequences and nuclear microsatellites. In contrast to the rather homogenous population structure typical of cave-dwelling bats in climax tropical ecosystems, a relatively pronounced isolation by distance and population diversification was observed. The evolution of this pattern could be ascribed to the complicated demographic history at higher latitudes related to the range margin fragmentation and complex geomorphology of the studied area. Lineages from East Africa and Arabia show divergent positions. Within the northwestern unit, the most marked pattern of the microsatellite data set is connected with insularity, as demonstrated by the separate status of populations from Saharan oases and Cyprus. These demes also exhibit a reduction in genetic variability, which is presumably connected with founder effects, drift and other potential factors related to island evolution as site-specific selection. Genetic clustering indicates a semipermeability of the desert barriers in the Sahara and Arabian Peninsula and a corridor role of the Nile Valley. The results emphasize the role of the island environment in restricting the gene flow in megabats, which is also corroborated by biogeographic patterns within the family, and suggests the possibility of nascent island speciation on Cyprus. Demographic analyses suggest that the colonization of the region was connected to the spread of agricultural plants; therefore, the peripatric processes described above might be because of or strengthened by anthropogenic changes in the environment.

High microsatellite and mitochondrial diversity in Anatolian native horse breeds shows Anatolia as a genetic conduit between Europe and Asia.

The horse has been a food source, but more importantly, it has been a means for transport. Its domestication was one of the crucial steps in the history of human civilization. Despite the archaeological and molecular studies carried out on the history of horse domestication, which would contribute to conservation of the breeds, the details of the domestication of horses still remain to be resolved. We employed 21 microsatellite loci and mitochondrial control region partial sequences to analyse genetic variability within and among four Anatolian native horse breeds, Ayvacik Pony, Malakan Horse, Hinis Horse and Canik Horse, as well as samples from indigenous horses of unknown breed ancestry. The aims of the study were twofold: first, to produce data from the prehistorically and historically important land bridge, Anatolia, in order to assess its role in horse domestication and second, to analyse the data from a conservation perspective to help the ministry improve conservation and management strategies regarding native horse breeds. Even though the microsatellite data revealed a high allelic diversity, 98% of the genetic variation partitioned within groups. Genetic structure did not correlate with a breed or geographic origin. High diversity was also detected in mtDNA control region sequence analysis. Frequencies of two haplogroups (HC and HF) revealed a cline between Asia and Europe, suggesting Anatolia as a probable connection route between the two continents. This first detailed genetic study on Anatolian horse breeds revealed high diversity among horse mtDNA haplogroups in Anatolia and suggested Anatolia's role as a conduit between the two continents. The study also provides an important basis for conservation practices in Turkey.

Mitochondrial DNA signatures at different spatial scales: from the effects of the Straits of Gibraltar to population structure in the meridional serotine bat (Eptesicus isabellinus).

The meridional serotine bat Eptesicus isabellinus is found in North Africa and the Iberian Peninsula. We analyzed the genetic structure of E. isabellinus at two different geographic scales to reveal the historical and ecological patterns that have shaped its populations. The role of the Straits of Gibraltar as an isolating barrier between African and Iberian populations is evaluated and the degree of genetic structure and female-mediated gene flow was assessed at a local scale between neighboring colonies. Populations of E. isabellinus from Iberia and northern Morocco show little genetic divergence and share mtDNA haplotypes, indicating that the Straits of Gibraltar are neither an impediment to dispersal nor a cause of genetic differentiation. Our results also suggest that E. isabellinus may have dispersed from western Andalusia into northern Morocco after the last glacial period. At a smaller geographic scale, the colonies studied showed high variation in genetic variability and structure, indicating that no female-mediated gene flow is present. This pattern is consistent with a described pattern of independent endemic viral circulation of the bat rabies virus EBLV-1, which was found when studying rabies dynamics in the same serotine bat colonies.

Effects of glucose on the activity of erythrocyte membrane Ca2+ATPase in subjects with normal and impaired glucose tolerance.

The effects of glucose on Ca2+ATPase activity of erythrocyte membranes were investigated under in vitro and in vivo conditions. Results of the study, in vitro, showed that Ca2+ATPase activity of erythrocyte membrane was decreased by increasing glucose concentrations (0-30 mM). When glucose-6-phosphate (0-100 mM) was used instead of glucose no significant change occurred in Ca2+ATPase activity. Tunicamycin (0.01 ng/ml) when added to the incubation media together with glucose prevented the decrease in Ca2+ATPase activity. The results of the studies in vivo showed that Ca2+ATPase activities of both male and female subjects with normal or impaired glucose tolerance were changed with time in a complex manner after an oral glucose loading. However, Ca2+ATPase activities of the subjects with impaired glucose tolerance were smaller than those of the corresponding normal controls even before glucose administration.

Glucose, glycated hemoglobin and fructosamine levels in essential hypertension.

It has been shown that a significant correlation is present between blood pressure and plasma glucose concentrations among nondiabetic individuals. Blood glycated hemoglobin, serum glucose and fructosamine concentrations were determined in forty nonobese individuals, twenty with untreated essential hypertension and twenty with normal blood pressure. The results demonstrated a decrease in fasting serum glucose and blood glycated hemoglobin values in hypertensive group compared to the healthy controls. Although, a minor decrease is observed in hypertensive group, no significant alteration is detected in fructosamine values between these two groups.

Effects of ozone on the activity of erythrocyte membrane Na(+)-K+ ATPase.

Ozone (5 mumol.min-1) inhibited the human erythrocyte membrane Na(+)-K+ ATPase (EC.3.6.1.39) activity in a time dependent manner. Inhibition was more pronounced for the first 5 min of ozone exposure in the directly ozone exposed membranes than in the membranes prepared from ozone exposed erythrocytes. However, Na(+)-K+ ATPase activities of both preparations were inhibited to the same extent (about 70%) at the end of 10 min ozone exposure. It was also determined that there was a close relationship between the decrease of enzyme activity and the increase in the thiobarbituric acid reactive substances in both types of preparations. Na(+)-K+ ATPase was inhibited by ozone even at the presence of vitamin E or vitamin C. However, the degree of the inhibitions and the amounts of thiobarbituric acid reactive products formed were smaller than the corresponding values found in the absence of these vitamins.

Effects of sulfhydryl compounds on the inhibition of erythrocyte membrane Na+(-)K+ ATPase by ozone.

Exposure of human erythrocyte membranes to ozone (5 mumol/10 min) resulted in the inhibition of erythrocyte membrane Na+(-)K+ ATPase (EC.3.6.1.39). It was determined that, the degree of enzyme inhibition in the directly ozone exposed membranes was greater than that of membranes obtained from ozone exposed intact erythrocytes. In the presence of varying concentrations (0-1.0 mM) of dithiotrethiol or mercaptoethanol Na+(-)K+ ATPase activities of both types of ozone exposed membranes were increased almost proportionally with the concentration of dithiotrethiol or mercaptoethanol however, the activities were still lower than the normal Na+(-)K+ ATPase value. The results indicate that, dithiotrethiol or mercaptoethanol prevent the enzyme inhibition by ozone in vitro. This suggests that the membrane thiol groups are primary targets for ozone and thereby preventing the oxidation of essential functional groups of enzyme protein.

Effects of trimetazidine on tissue damage in kidney after hindlimb ischemia-reperfusion.

The objective of this study was to investigate the effects of trimetazidine (TMZ) on tissue damage in kidney after hindlimb ischemia-reperfusion (I/R), by assessing blood biochemical assay and histopathological analysis. Adult male Wistar rats were divided into two groups. TMZ 10 mg kg(-1)day(-1) was administrated twice a day for 10 days to the treatment group (group T, n=10). Sham group was given only 5% gum arabic (group S, n=10). On 11th day of treatment, 8h I/R period was performed on right hindlimb of the rats. At the end of reperfusion period, a 5 ml blood withdrawn from ascending aorta for biochemical assays and their right kidneys were harvested for histopathological examination. Superoxide dismutase, Na(+)-K(+) ATPase, and reduced glutathione levels were significantly increased in group T (P<0.001). On the other hand, myeloperoxidase and malondialdehyde levels were significantly less in group T than group S (P<0.001). Kidneys from the sham-operated group displayed intense leukocytic infiltration in histopathological examination. These overall results strongly suggested that TMZ contributes renal protection from hindlimb I/R injury by decreasing systemic oxidative stress.