Stone Throwing as a Sexual Display in Wild Female Bearded Capuchin Monkeys,Sapajus libidinosus

Capuchin monkeys (Sapajus spp.) in captive settings frequently manipulate and throw objects. In the wild, they may push or drop stones and sticks toward targets during inter- or intraspecific threat displays. In addition, female capuchin monkeys exhibit a broad repertoire of behaviors during their proceptive period, including facial expressions, vocalizations, stereotyped body postures, and touch-and-run behavior. This study reports stone throwing as a newly-described communicative behavior during the proceptive display of females in a group of bearded capuchin monkeys (S. libidinosus) in Serra da Capivara National Park, Brazil. During a two-year study, three females from one group were seen throwing stones at males during their proceptive phase. After this period, three other females in the same group exhibited the same behavior. Although it may be possible that this pattern is the result of several independent innovations by each female, the apparent absence of this behavior in other groups leads us to suggest that we have documented the diffusion of a new behavioral trait or tradition within this capuchin social group.     

Nuclear diacylglycerol kinases: emerging downstream regulators in cell signaling networks

There exists an active lipid metabolism in the nucleus, which is regulated differentially from the lipid metabolism taking place elsewhere in the cell. Evidence has been accumulated that nuclear lipid metabolism is closely involved in a variety of cell responses, including proliferation, differentiation, and apoptosis. A fundamental lipid second messenger which is generated in the nucleus is diacylglycerol, that is mainly known for its role as an activator of some protein kinase C isoforms. Diacylglycerol kinases attenuate diacylglycerol signaling by converting this lipid to phosphatidic acid, which also has signaling functions. Ten mammalian diacylglycerol kinase isoforms have been cloned so far, and some of them are found also in the nucleus, either as resident proteins or after migration from cytoplasm in response to various agonists. Experiments using cultured cells have demonstrated that nuclear diacylglycerol kinases have prominent roles in cell cycle regulation and differentiation. In this review, the emerging roles played by diacylglycerol kinases in the nucleus, such as the control of G1/S phase transition, are discussed.     

Differences between Dianthus caryophyllus L. cultivar in in vitro growth and morphogenesis are related to their ethylene production

The involvement of ethylene in the vitro development of shoots from nodal segments of two cultivars of carnation (Dianthus caryophyllus L.) was studied. Shoots of cv. Barbaret Antares showed low hyperhydricity in contrast with the high levels showed by cv. Barbaret Tanga when both were cultured in airtight culture vessels. Longer shoots were produced, in both cases, when the rate of gas exchange in the culture vessel was increased by using vented closures, which also prevented hyperhydricity and increased the multiplication coefficient in cultures of Barbaret Tanga.The two cultivars produced ethylene throughout the culture period but, a higher amount was produced during the first, second and fourth weeks in culture by the cultivar more sensitive to ventilation (Barbaret Tanga). Trapping ethylene did not produce any effect on cv. Barbaret Antares but improved the quality of cv. Barbaret Tanga explants, decreasing hyperhydricity and increasing the number of shoots, the length of the main shoot and the multiplication coefficient. These effects were more marked when ethylene was trapped during the first two weeks in culture.     

The effect of cytokinins on growth and sexual organ development in the gametophyte of <Emphasis Type="Italic">Blechnum spicant</Emphasis> L.

In this study, we report the role of exogenous and endogenous cytokinins on growth and sexual organ development in the fern Blechnum spicant L. Spore-derived gametophytes (SG) were cultured in full-strength Murashige and Skoog (1962) liquid medium supplemented with (a) 4.44 μMN⁶-benzyladenine (BAP), (b) a crude extract from mature female gametophytes, and (c) 4.44 μM BAP in combination with the crude extract from mature gametophytes, respectively. Both BAP and the crude extract delayed the gametophyte development, and this effect was increased when they were added together. With respect to sexual organ development, BAP inhibited the sexual organ formation, while the crude extract favored antheridia formation; however, when added together, the percentage of antheridia decreased. The endogenous level of the cytokinins cis-zeatin (cZ), cis-zeatin-riboside (cZR), dihydrozeatin (DHZ), dihydrozeatin riboside (DHZR), isopentenyl adenine (iP), isopentenyl adenosine (iPR), isopentenyl-9-glucoside (iP9G), trans-zeatin (tZ), and trans-zeatin riboside (tZR) were analyzed in female and male gametophytes of B. spicant L. The endogenous levels of cytokinins tZ, cZ, DHZ, cZR, iP, and iPR were higher in female gametophytes than in male gametophytes, with the endogenous iP and iPR content being increased more than 300 and 400 times, respectively.     

Anting in a Semifree-ranging Group of <Emphasis Type="Italic">Cebus apella</Emphasis>

Capuchins apply many organic materials, especially leaves, to their skin. Protection against ectoparasites is the most commonly discussed explanation for the behavior. We describe fur rubbing with carpenter ants(Camponotus rufipes) by semifree-ranging tufted capuchins(Cebus apella) in the Tietê Ecological Park, S?o Paulo, Brazil. Carpenter ants produce and secrete high concentrations of formic acid, which repels tick nymphs. Anting occurred significantly more often during months of seasonal incidence of nymphs of the tick Amblyomma cajennense, and the behavior was not related to ant-eating. We argue that anting behavior in tufted capuchins fits the hypothesis of protection against ectoparasites.     

Stone tool use by wild capuchin monkeys (<Emphasis Type="Italic">Sapajus libidinosus</Emphasis>) at Serra das Confusões National Park,Brazil

Capuchin monkeys (Sapajus spp.) are proficient tool users, and the use of stone tools occurs in several populations, mostly to crack open encased foods. Two well-studied Brazilian populations of Sapajus libidinosus inhabit Fazenda Boa Vista and Serra da Capivara National Park and present different behavioral sets regarding tool use. Serra das Confusões National Park (SCoNP) lies between those sites, but little is known about the capuchin monkey population that lives there. To begin unraveling the capuchin behavior in this area, we conducted a brief survey for tool use sites. We found indirect evidence that capuchin monkeys at SCoNP use stone hammers to crack open at least four species of seeds and fruits. Plant reproductive parts there are processed with stone tools in a similar pattern to the other sites. Further study is needed to directly observe tool use by capuchin monkeys at SCoNP, verify the occurrence of other possible types of tool use in this population, and thus fully compare their tool use repertoire to that of other populations.