Dominance,Coloration, and Social and Sexual Behavior in Male Drills <Emphasis Type="Italic">Mandrillus leucophaeus</Emphasis>

Sexual selection has driven the evolution and elaboration of a wide variety of displays and ornaments in male nonhuman primates, including capes, cheek flanges, and sexual coloration. Among the most sexually dimorphic of all primates is the drill (Mandrillus leucophaeus), the males of which can be 3 times the mass of females, possess large canines, and exhibit extremely bright sexual skin coloration. However, the function of male coloration in this species has never been examined. Here, we present data on male color (measured objectively using digital photography), dominance rank, measures of male-female association, and key sexual behaviors, of adult male drills (n = 17) living in four semi free-ranging enclosures at the Drill Rehabilitation and Breeding Center in Nigeria. We test the hypothesis that male coloration is a badge of status, indicating dominance rank, and the hypothesis that male coloration attracts females. We found that male coloration did indicate rank, and that high ranking, strongly colored males were more likely to associate with adult females, and more specifically with fully tumescent females. These males also engaged in more sexual activity. However, measures of male-female association and sexual behaviors were not related to male color once rank had been taken into consideration; i.e., for males of a given rank, females did not prefer those that were more colorful. We discuss the results in light of what is known about the wild drill social system, in which unfamiliar individuals may come together in “supergroups,” and in which quality indicators of competitive ability may be particularly important.     

Stereospecific reactivation of human brain and erythrocyte acetylcholinesterase inhibited by 1,2,2-trimethylpropyl methylphosphonofluoridate (soman)

Human erythrocyte and brain acetylcholinesterase are preferentially inhibited by the P(-)-isomers of C(+/-)P(+/-)-soman. The enzymes inhibited by the P(-)-isomers behave similarly with respect to oxime-induced reactivation and aging. HI-6 is the best reactivator for C(+)P(-)-soman-inhibited acetylcholinesterases. Oxime-induced reactivation of the C(-)P(-)-soman-inhibited acetylcholinesterases is much more difficult to achieve.     

Role of membranes and energy-producing reactions in cellular processing of insulin in primary cultures of rat hepatocytes

Incubation of primary cultures of rat hepatocytes with the local anesthetics, procaine or lidocaine, had little or no effect on insulin uptake or degradation but caused an inhibition of insulin-stimulated glycogenesis. While exposure of cultures to the amines, monodansylcadaverine or CH3NH2, resulted in significant dose-dependent decreases in glycogenesis, only monodansylcadaverine (an inhibitor of receptor clustering) decreased uptake whereas CH3NH2 (a lysosomotropic agent) caused increases in both insulin uptake and degradation. When cells were treated with agents which inhibit glycolysis (NaF, 2-deoxy-D-glucose) or oxidative metabolism (2,4-dinitrophenol, carbonyl cyanide m-chlorophenyl hydrazone, NaN3, antimycin A), pronounced inhibitions of each of the bioactivities studied (syntheses of glycogen, protein, lipid) were observed, but only the glycolytic inhibitors decreased insulin uptake. These results suggest that insulin is internalized by an endocytotic process involving receptor clustering and requiring metabolic energy derived from glycolysis. The post-receptor biosynthetic processes involved in the expression of the biological activities of insulin (syntheses of glycogen, protein, lipid) require energy produced by oxidative metabolism while the degradation of insulin is carried out by nonlysosomal mechanisms which are not energy-requiring.     

Demonstration of the presence of G-proteins in hepatic microsomal fraction

The presence of G-proteins in isolated hepatic microsomal vesicles is demonstrated. The G-proteins were identified by their capacity to be ADP-ribosylated by cholera and pertussis toxins. Cholera toxin identified 42 and 45 kDa proteins, corresponding to alpha s-1 and alpha s-2, respectively. Pertussis toxin identified a 40 kDa protein corresponding to alpha i. The microsomal G-proteins are identical to the corresponding G proteins of the plasma membrane, but are present in different proportions; the microsomes have considerably less alpha s proteins than the plasma membrane.     

A comparison of the respiratory chain in particles from Paracoccus denitrificans and bovine heart mitochondria by EPR spectroscopy

A study is presented on the EPR characteristics of the paramagnetic groups in the respiratory chain present in membrane particles of Paracoccus denitrificans, the respiratory system of which is very similar to that in submitochondrial particles from beef heart. All paramagnetic prosthetic groups of the mitochondrial system are also found in the bacterial plasma membrane. Their properties suggest that the respiratory groups are embedded in very similar protein environments in the two systems.     

Regulation of Apoptosis in Nonapeptidergic Neurons of Rat Hypothalamus by Catecholamines in Experiments in vitro

Effects of noradrenaline (NA) and dopamine (DA) on apoptosis of nonapeptidergic neurons of supraoptic (SON) and paraventricular (PVN) nuclei of hypothalamus of male Wistar rats was studied in experiments in vitro. Incubation of hypothalamic sections in the medium with added NA was shown to induce an increase of the amount of pro-apoptotic protein caspase-9 in the nonapeptidergic neurons of the SON and PVN. A comparison of the level of neuronal NO-synthase with the level of caspase-9 expression in these neurons allows concluding that NA leads to initiation of apoptosis in neurons of the SON with mediation by nitric oxide (NO). In the PVN, the NA-induced initiation of apoptosis does not depend on the NO level. Addition of DA to the incubation medium results in an increase of the caspase-9 amount only in PVN neurons regardless of the NO content. The absence of neuronal death after the NA-induced increase of the caspase-9 level in the cells of SON and PVN seems to be due to increased expression of the anti-apoptotic protein bcl-2. Protection of the PVN neurons from death after addition of DA to the incubation medium is probably independent of the expression level of bcl-2. Thus, in the nonapeptidergic neurons of the SON and PVN, which are related by origin and by performed functions, modulation of the process of apoptosis by elevated concentrations of NA and DA is realized by different mechanisms.