Cross-species comparison of Drosophila male accessory gland protein genes

Drosophila melanogaster males transfer seminal fluid proteins along with sperm during mating. Among these proteins, ACPs (Accessory gland proteins) from the male's accessory gland induce behavioral, physiological, and life span reduction in mated females and mediate sperm storage and utilization. A previous evolutionary EST screen in D. simulans identified partial cDNAs for 57 new candidate ACPs. Here we report the annotation and confirmation of the corresponding Acp genes in D. melanogaster. Of 57 new candidate Acp genes previously reported in D. melanogaster, 34 conform to our more stringent criteria for encoding putative male accessory gland extracellular proteins, thus bringing the total number of ACPs identified to 52 (34 plus 18 previously identified). This comprehensive set of Acp genes allows us to dissect the patterns of evolutionary change in a suite of proteins from a single male-specific reproductive tissue. We used sequence-based analysis to examine codon bias, gene duplications, and levels of divergence (via dN/dS values and ortholog detection) of the 52 D. melanogaster ACPs in D. simulans, D. yakuba, and D. pseudoobscura. We show that 58% of the 52 D. melanogaster Acp genes are detectable in D. pseudoobscura. Sequence comparisons of ACPs shared and not shared between D. melanogaster and D. pseudoobscura show that there are separate classes undergoing distinctly dissimilar evolutionary dynamics.     

Reproductive division of labor, dominance, and ecdysteroid levels in hemolymph and ovary of the bumble bee Bombus terrestris

To determine whether ecdysteroids are associated with reproductive division of labor in Bombus terrestris, we measured their levels in hemolymph and ovaries of queens and workers. Queens heading colonies had large active ovaries with high ecdysteroid content, whereas virgin gynes and mated queens before and after diapause had undeveloped ovaries with low ecdysteroid content. The hemolymph ecdysteroid titer was rather variable, but in a pooled analysis of mated queens before and after diapause versus colony-heading queens, ecdysteroid titers were higher in the latter group. In workers, agonistic behavior, ovarian activity, ovarian ecdysteroid content, and hemolymph ecdysteroid titers were positively correlated, and were lowest when a queen was present. In queenless workers, ecdysteroid levels were elevated in dominant workers, and were also influenced by the presence of brood and by group demography; hormone levels were higher in bees kept in larger groups. These findings are consistent with the premise that in B. terrestris the ovary is the primary site of ecdysteroid synthesis, and they show that ecdysteroids levels vary with the social environment.     

Schistosomiasis in Lake Malawi: Relationship of Fish and Intermediate Host Density to Prevalence of Human Infection

Prior to 1985, the open waters of Lake Malawi were free from schistosome transmission. Over the past decades, however, the prevalence of urinary schistosomiasis has increased dramatically in the southern part of the lake. We found the prevalence of human schistosomiasis in school-aged children to be negatively correlated with the density of molluscivorous fishes. Specifically, the increased infection rate in southern Lake Malawi between 1978 and 1991 is coincident with the reduction in numbers of snail-eating fishes. During 2003, we determined the relative abundance of molluscivorous fishes and snail density at 18 sites throughout the lake and schistosome infection in school-aged children living in selected lakeshore communities of Lake Malawi. At the 18 sites sampled in 2003, we found that snail abundance decreased with an increase in abundance of snail-eating fishes. Furthermore, the 2003 samples showed that the abundance of snail-eating fishes increased and there was a reduction in schistosomiasis in school-aged children in Chembe Village. We believe that we will not observe a return to the 1978 infection rates until these fishes continue to increase and inhabit shallower waters.     

Inhaled nitric oxide decreases infarction size and improves left ventricular function in a murine model of myocardial ischemia-reperfusion injury

To learn whether nitric oxide (NO) inhalation can decrease myocardial ischemia-reperfusion (I/R) injury, we studied a murine model of myocardial infarction (MI). Anesthetized mice underwent left anterior descending coronary artery ligation for 30, 60, or 120 min followed by reperfusion. Mice breathed NO beginning 20 min before reperfusion and continuing thereafter for 24 h. MI size and area at risk were measured, and left ventricular (LV) function was evaluated using echocardiography and invasive hemodynamic measurements. Inhalation of 40 or 80 ppm, but not 20 ppm, NO decreased the ratio of MI size to area at risk. NO inhalation improved LV systolic function, as assessed by echocardiography 24 h after reperfusion, and systolic and diastolic function, as evaluated by hemodynamic measurements 72 h after reperfusion. Myocardial neutrophil infiltration was reduced in mice breathing NO, and neutrophil depletion prevented inhaled NO from reducing myocardial I/R injury. NO inhalation increased arterial nitrite levels but did not change myocardial cGMP levels. Breathing 40 or 80 ppm NO markedly and significantly decreased MI size and improved LV function after ischemia and reperfusion in mice. NO inhalation may represent a novel method to salvage myocardium at risk of I/R injury.     

Mesenchymal stem cells transmigrate over the endothelial barrier

Mesenchymal stem cells (MSCs) seem to be a useful tool for cellular therapy in injured tissues, e.g. myocardial infarction or cardiomyopathies resulting in heart failure. For therapeutic approaches it is crucial that MSCs cross the endothelial barrier especially in intravascular or rather intracoronary application. Until today little is known about MSCs transmigrating across the endothelium. We performed co-culture experiments of MSCs on an endothelial monolayer to analyse direct interactions. An increasing flattened morphology of the MSCs was followed by a total integration into the monolayer after 2h. We repeated these experiments in isolated heart perfusions with gold-labelled MSCs. Using electron microscopy we detected MSCs exhibited direct cell-cell contacts. Tight junctions between the endothelial cells became abolished resulting in a distinct split between the cells. MSCs developed tight cell-cell contacts and became integrated into the endothelial wall of the capillary vessel. Finally, using confocal laser scanning microscopy, we assessed the ability of the MSCs to fully pass the endothelial barrier. Within the first 30 min, 30+/-8% of MSCs transmigrated, increasing to about half at 60 min (50+/-8%), whereas after 120 min the rate remained nearly unchanged (53+/-10%). This work demonstrates the capability of MSCs for transendothelial migration. Moreover we showed that the vast majority of MSCs migrated within 30 min, an important finding for the exposure times in clinical settings.     

Cranial anatomy of the Paleocene plesiadapiform Carpolestes simpsoni (Mammalia, Primates) using ultra high-resolution X-ray computed tomography, and the relationships of plesiadapiforms to Euprimates

Central to issues surrounding the origin of euprimates, affinities of Paleocene Carpolestidae have been controversial. Carpolestids have been classified as plesiadapoid primates, tarsiiform euprimates, dermopterans, or the sister taxon of euprimates to the exclusion of other plesiadapiforms, based exclusively on dental or postcranial data. Newly discovered crania of Carpolestes simpsoni from the latest Paleocene of the Clarks Fork Basin, Wyoming, are the first described for the family Carpolestidae. The two best preserved skulls were studied using ultra high-resolution X-ray computed tomography. Comparison of these specimens to those of other stem primates (Plesiadapiformes) demonstrates that the diversity of cranial morphology in this group is greater than previously thought. Carpolestes differs from euprimates and is similar to other plesiadapiforms (Ignacius and Plesiadapis) in lacking a postorbital bar and having a relatively long rostrum. Carpolestes is similar to fossil euprimates and Plesiadapis in having a bullar morphology consistent with a petrosal origin, and differs from Ignacius, in which the bulla is composed of the entotympanic. Carpolestes differs from primitive euprimates and all other known plesiadapiforms in possessing a two-chambered auditory bulla, similar to that of modern Tarsius. However, Carpolestes had an internal carotid artery (ICA) that took a transpromontorial route from a posteromedially positioned posterior carotid foramen (pcf), unlike Tarsius, in which this artery takes a perbullar route from an anterolaterally positioned pcf. Carpolestes has clear grooves on the promontorium for both the promontorial and stapedial arteries, indicating that it had an unreduced internal carotid circulation, similar to that of early euprimates. Carpolestes differs from primitive euprimates and some specimens of Ignacius in not having bony tubes surrounding the branches of the ICA. Cladistic analysis of cranial data fails to support a close relationship of Carpolestidae to either tarsiiform euprimates or extant Dermoptera, but suggests a close relationship between Carpolestidae, Plesiadapidae, and Euprimates.     

Beta3-adrenergic eNOS stimulation in left ventricular murine myocardium

This study investigates mechanisms underlying beta3-adrenergic activation of the endothelial nitric oxide synthase (eNOS) in myocardial tissue of wild-type (WT) and beta3-adrenoceptor knockout (beta3-KNO) mice, in the absence and presence of BRL 37344 (BRL), the preferential beta3-adrenoceptor selective agonist. Nitric oxide (NO)-liberation was measured after the application of BRL (10 micromol/L), using fluorescence dye diaminofluorescein (DAF), in left ventricular cardiac preparations. Phosphorylation of eNOSSer1177, eNOSThr495, eNOSSer114, and eNOS translocation, and alterations of 8-isoprostaglandin F2alpha (a parameter for reactive oxygen radical generation), after application of BRL (10 micromol/L), were studied using immunohistochemical stainings in isolated, electrically stimulated (1 Hz) right atrial (RA) and left ventricular (LV) myocardium. An increased NO release after BRL application (10 micromol/L) was observed in the RA and LV myocardial tissue of WT mice, but not in beta3-KNO mice. This NO liberation in WT mice was paralleled by an increased eNOSSer1177, but not eNOSThr495, phosphorylation. A cytosolic eNOS translocation was observed after the application of BRL (10 micromol/L) only in the RA myocardial tissue of WT mice. A BRL (10 micromol/L)-dependent increase in eNOSSer114 phosphorylation was observed only in the LV myocardial tissue of WT mice; this was paralleled by an increase in 8-isoprostaglandin F2alpha. In murine myocardium, 3 beta3-adrenoceptor-dependent activation pathways for eNOS exist (i.e., a translocation and phosphorylation of eNOSSer1177 and eNOSSer114). These pathways are used in a regional-dependent manner. beta3-adrenergic oxygen-derived free radical production might be important in situations of enhanced beta3-adrenoceptor activation, as has been described in human heart failure.