Complex patterns of grooming and sexual activity in Barbary macaques (Macaca sylvanus)

Grooming in primates is often considered a “currency” that can be exchanged for other “services” or “commodities” such as reciprocal grooming, coalitionary support, infant handling, tolerance around food sources, active food sharing, or mating opportunities. Previous studies on primate grooming‐for‐sex exchange viewed the males as the demanding class, with the females as suppliers of mating opportunities. In this study, we examine the broader context of grooming‐for‐mating exchange in Barbary macaques in Gibraltar. Our data show that Barbary macaque males groom females with whom they are mating more frequently and for longer periods than other females, and the relationship between grooming and mating remains significant in both sexual and nonsexual contexts. In addition, females groomed males with whom they were mating more frequently and for longer periods than other males. In both sexes, grooming was observed to be far more frequent and to occur for longer durations in sexual compared to nonsexual contexts. We did not find any difference in grooming behavior between presexual and postsexual contexts. Our data suggest that there is no simple model to describe Barbary macaque grooming patterns in sexual contexts. Although our results are partly consistent with male use of grooming as payment for mating, broadly assessed grooming‐mating patterns cannot be solely explained by a male‐driven grooming‐for‐mating exchange.     

Effect of thiostrepton and 3′-terminal fragments of aminoacyl-tRNA on EF-Tu and ribosome-dependent GTP hydrolysis

The effect of the antibiotics thiostrepton and micrococcin on EF-T_u-catalyzed (ribosome-dependent) GTP hydrolysis in the presence of A-Phe, C-A-Phe, or C-C-A-Phe (related to the sequence of the 3′-terminus of aminoacyl-tRNA)(System I) or by methanol (‘uncoupled GTPase’, System II) was investigated. In System I, thiostrepton increases the binding affinities of the effectors to the EF-T_u·GTP·70 S ribosome complex, as well as the extent of the GTP hydrolysis, while the K^GTP_m is virtually unchanged. Similarly, in the uncoupled system (System II) and in the absence of effectors, thiostrepton significantly increases V^GTP_max, whereas K^GTP_m remains unaffected. Micrococcin is without any effect in both systems. The ‘uncoupled GTPase’ (in System II) is also strongly inhibited by C-A-Phe. The results indicate the crucial role of the EF-T_u site which binds the aminoacylated C-C-A terminus of aminoacyl-tRNA in promoting GTP hydrolysis. It follows that the binding of the model effectors (such as C-C-A-Phe) to that site is favorably influenced by the interaction of thiostrepton with the 50 S ribosomal subunit, whereas thiostrepton, per se, does not influence the affinity of EF-T_u for GTP.     

Effect of Lanthanum on the Release of Acetylcholine from the Myenteric Plexus and on Its Activation by Ouabain and Electrical Stimulation

The effect of lanthanum ions (La3+) on the release of acetylcholine (ACh) from longitudinal muscle strips of the guinea pig ileum with the myenteric plexus attached was investigated. After an exposure of the tissue to 2 mM LaCl3 for 18 min the rate of ACh release was increased approximately eightfold and the increased release lasted for more than 100 min. The augmented release of ACh was accompanied by enhanced synthesis. At the end of the experiments (102 min after LaCl3 had been removed), when the release of ACh was still more than six times higher than in controls, the content of ACh was the same in La3+-treated and untreated tissues. Electrical field stimulation failed to cause a further increase in the release of ACh from La3+-pretreated preparations whereas ouabain released considerable more ACh when compared to controls. It is concluded from this difference that electrical stimulation and ouabain release ACh from different pools.     

Calcium-Independent Release of Acetylcholine from Electric Organ Synaptosomes and Its Changes by Depolarization and Cholinergic Drugs

Chemiluminescent detection was applied to measure the continuous spontaneous Ca2+-independent liberation of acetylcholine (ACh) from Torpedo electric organ synaptosomes. Differentiation between the release of ACh and choline was achieved by inhibiting cholinesterases with phospholine, and a way to quantify the continuous release was devised. The method permitted measurements during short time intervals from minute amounts of tissue and without an accumulation of ACh in the medium. Synaptosomes continuously liberated small amounts of ACh during incubations in the presence of 3 mM K+ and in the absence of Ca2+. The spontaneous liberation of ACh was similar both quantitatively and qualitatively at pH values of 8.6 and 7.8. It was unaltered by MgCl2 (10.4 mM), 2-(4-phenylpiperidino)cyclohexanol (10 microM), ouabain (104 microM), atropine (10 microM), and valinomycin (102 nM). Carbamoylcholine brought about a decrease, which could be partially reversed by atropine. The Ca2+-independent output of ACh was increased considerably when the concentration of K+ ions was raised (eightfold at 103 and 35-fold at 203 mM K+). Carbamoylcholine (104 microM) blocked the increase in ACh release produced by high K+; this effect of carbamoylcholine was not reversed by atropine (10 microM). When Ca2+ was added to synaptosomes depolarized by a high concentration of K+, the amount of ACh released during the first 1-3 min after the addition of Ca2+ was at least 20 times higher than in the absence of Ca2+, but the release returned rapidly to predepolarization values. Similarly high values of ACh release could be achieved by adding Ca2+ plus the ionophore A23187 and even higher values by adding Ca2+ plus gramicidin.(ABSTRACT TRUNCATED AT 250 WORDS)     

New principles of ion exchange preparative chromatography and their applications for isolation, purification and super purification of antibiotics]

New types of structurally segregated heteronetwork biosorbents with given parameters of heterogeneity and porosity have been developed. Physico-chemical characteristics of the biosorbents on the basis of which one can predict optimal structures of ion exchangers to be used in preparative chromatography of biologically active compounds were studied. A new principle of sequential displacement of ions of organic compounds, in particular antibiotics, adsorbed on selective biosorbents with a high adsorption capacity was developed, which enables purification and superpurification of the desired compound. The method is based on the effect of small thermodynamic shifts in physico-chemical parameters of the elution system, which results in preparative separation of substances with close properties and in purification of the desired compound from microadmixtures. The "small shift effect" is realized in the case of limiting thermodynamic and kinetic parameters of heterogeneous mass exchange and with biosorbents possessing a highly selective adsoprtion capacity.     

Effects of short-term and prolonged aerogenic hypoxia on gamma-glutamyl transpeptidase activity in the brain,liver, and biological fluids of young rats

Posthypoxic fluctuations in the levels of two excitatory amino acids, glutamate and aspartate, may be related to changes in mechanisms(s) which are responsible for their reuptake. As gamma-glutamyl transpeptidase (GGT) plays a role in mediating the uptake of glutamate and aspartate into various compartments of the brain, we studied changes in the activity of this enzyme in main regions of the brain in young and adult rats. We found a posthypoxic increase in bound GGT activity in some brain regions of 18-day-old animals after acute exposure, but no changes were observed after prolonged altitude hypoxia, with the exception of a decrease in cortical GGT activity. In contrast, acute hypoxia decreased GGT activity in the cortical capillaries to 59%, but prolonged hypoxic exposure was ineffective. However, the activity of soluble GGT in the cerebrospinal fluid of both groups of rats was several-times elevated in comparison with controls. At the same time, bound GGT activity was increased in the liver after acute or prolonged altitude hypoxia. The soluble GGT activity in plasma was only increased after prolonged exposure. Ninety days after prolonged hypoxic exposure the bound GGT activity was reduced in all brain regions to about 60–70% of controls (significantly higher in females than in males) as long-term developmental sequel from early postnatal hypoxia.     

Diploids in Microsporum gypseum

The paper studies diploids in dermatophyteMicrosporum gypseum. They were isolated as the more rapidly growing sectors from heterokaryons on minimal medium. They are characterized by their wild morphology, conidiation and growth rate, and they are prototrophic. In their genome they contain all the markers present in both mutant components.