Pejibaye palm (Bactris gasipaes,Arecaceae): Multi-use potential for the lowland humid tropics

Pejibaye (Bactris gasipaes) was domesticated and widely used in the lowland humid neotropics during pre-Colombian times. Several research programs are underway to study and improve the species for use by farmers in ecologically suitable regions. Five breeding programs are outlined, each for a use to which the pejibaye may be put: (1) palmito (heart of palm), (2) whole fruit for human consumption, (3) flour and meal production, (4) oil production, and (5) animal ration from residues or purposefully bred varieties. Yield estimates and breeding problems are discussed. It is certain that the pejibaye can again become an important crop for the humid tropics.     

Spatial distribution of Tephrocactus aoracanthus (Lem.) Lem. in relation to shrubs in the hyperarid regions of west‐central Argentina

The spatial intraspecific and interspecific distribution of Tephrocactus aoracanthus (Lem.) Lem. was studied using univariate and bivariate point pattern analysis, at landscape scale in four different physiographic units and at microscale in terms of the shrubs found in those units. The influence of shrubs on photosynthetically active radiation and on soil temperature under their canopies was analysed. Results show a high environmental variability in light and temperature under shrubs that generally has no influence on the distribution of T. aoracanthus. Apparently, this cactus has great ability to adapt to different conditions of both photosynthetically active radiation and temperature. However, intraspecific distribution was highly clustered in all physiographic units, independently of bushes. Possibly, the mode of seed dispersal and the rooting of cladodes at small scale are the main processes that determine the strong intraspecific clustering of T. aoracanthus.     

Monomorphic Region of the Serotonin Transporter Promoter Gene in New World Monkeys

Genetic variation in the human serotonin system has long been studied because of its functional consequences and links to various neuropsychiatric and behavior‐related disorders. Among non‐human primates, the common marmosets (Callithrix jacchus) and tufted capuchins monkeys (Cebus apella) are becoming increasingly used as models to study the effects of genes, environments, and their interaction on physiology and complex behavior. In order to investigate the independent functions of and potential interactions between serotonin‐related genes, anxiety and neuropsychiatric disorders, we analyzed the presence and variability of the serotonin transporter gene‐linked polymorphic region (5‐HTTLPR) in marmoset and capuchin monkeys. By PCR and using heterologous primers from the human sequence, we amplified and then sequenced the corresponding 5‐HTT region in marmosets and capuchins. The resulting data revealed the presence of a tandem repeat sequence similar to that described in humans, but unlike humans and other Old World primates, no variable length alleles were detected in these New World monkeys, suggesting that if serotonin transporter is involved in modulating behavior in these animals it does so through different molecular mechanisms. Am. J. Primatol. 74:1028‐1034, 2012. © 2012 Wiley Periodicals, Inc.     

Impact of grazing on species composition: Adding complexity to a generalized model

The impact of grazing widely differs among plant communities. A generalized model published in 1988 proposed that this variation could be accounted for by the interaction between primary productivity and the evolutionary history of grazing. As productivity increased, the model predicted larger changes of species composition. Evolutionary history of grazing interacted with productivity: the changes in low‐production systems were smaller if evolutionary history was long, whereas the changes in high‐production systems were independent of evolutionary history. In this paper, we focus on: (i) the difficulties of determining the evolutionary history of grazing of a community, and (ii) additional mechanisms, which, as a sequence of filters in the process of community assembly, could be operating across the gradient of primary production. Assigning a given evolutionary history of grazing to a site has been difficult due to the lack of information on the historical population and distribution of herbivores with an adequate spatial and temporal resolution, and the lack of agreement on the size of the relevant evolutionary time window. Regarding the variation through a gradient of primary production, we propose three additional mechanisms coherent with the prediction of the model. First, the regional pool of available species increases with primary production. Second, grazing intensity (consumption as a proportion of above‐ground production) also increases with primary production. Third, the strength of interspecific positive biotic interactions that protect plants from herbivores decreases with primary production. We highlight an additional potential mechanism, seed dispersal, whose variation across the gradient of productivity is not yet sufficiently understood. By connecting the logic of environmental filters to explain community assemblage with the original proposition of the generalized model, we suggest a series of research lines that can lead to a better understanding of why different communities respond differently to grazing.     

Killing in the Pliocene: shark attack on a dolphin from Italy

Abstract: Shark bite marks, including striae, sulci and abrasions, in a well‐preserved fossil dolphin skeleton referred to Astadelphis gastaldii (Cetacea, Delphinidae) from Pliocene sediments of Piedmont (northern Italy), are described in detail. The exceptional combination of a fossil dolphin having a significant part of the skeleton preserved and a large number of bite marks on the bones represents one of the few detailed documentations of shark attack in the past. Most bite marks have been referred to a shark about 4 m long with unserrated teeth, belonging to Cosmopolitodus hastalis, on the basis of their shape and their general disposition on the dolphin skeleton. According to our hypothesis, the shark attacked the dolphin with an initial mortal bite to the abdomen from the rear and right, in a similar way as observed for the living white shark when attacking pinnipeds. A second, less strong, bite was given on the dorsal area when the dolphin, mortally injured, probably rolled to the left. The shark probably released the prey, dead or dying, and other sharks or fishes probably scavenged the torn body of the dolphin.     

Evolution of intrinsic reproductive isolation among four North American populations of Rhagoletis pomonella (Diptera: Tephritidae)

Across its range in North America, four geographically separated, ecologically and genetically diverged populations of hawthorn (Crataegus)‐infesting Rhagoletis pomonella (Diptera: Tephritidae) flies inhabit the Eje Volcánico Trans Mexicano (EVTM), the Sierra Madre Oriental (SMO), the Chiapas Highlands (CHIS) and the USA. Here, we tested whether these four populations are reproductively isolated by any intrinsic, nonhost‐related, pre‐ or postmating barriers to gene flow. Crossing experiments suggested that a low level of host‐independent prezygotic isolation may exist between hawthorn flies from EVTM and the three other populations, but only with respect to a slight reduction in copulation duration in EVTM matings. Some evidence for postmating isolation was found, again primarily involving EVTM crossed to SMO, CHIS and US flies. Certain crosses produced no (SMO male × EVTM female) or few (EVTM male × CHIS female; CHIS male × SMO female) F1 hybrid offspring. F2 crosses were generally fertile, except for US male × CHIS female matings. Inherent reproductive isolation therefore appears to be quantitative rather than absolute between populations, as the possibility for gene flow exists through at least some combinations of mating among EVTM, SMO, CHIS and US flies. Our results are consistent with a recently advanced hypothesis that episodic introgression from Mexico into the USA has played a role in providing genetic variation, facilitating sympatric host race formation and the adaptive radiation of the R. pomonella sibling species' complex in the USA. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 213–223.     

Biosynthesis of erythromycin and its metabolic conditions

В actinomycete Streptomyces erythreus arsenite препятствует второй ш агокислительные decarboxylation из pyruvic кислотадо уксусной кис лоты, то есть окисления а цетальдегидТаким обра зом в присутствииarsenite в зат опленных культуры pyruvic arsenite в затопленных культуры pyruvic начало, но потом anoxidative Проце сс биосинтеза acetylmethyl-carbinol из э тих субстратов более ин тенсивная. Сопутствующ ей ингибирование эритр омицинпроизводства по казывает, что в курс инте нсивной, не-окислительн ые метаболические прео бразование pyruvic кислоты и ацетальдегид в сопров ождении acetylmethylcarbinol синтез в мес те окислительные испол ьзования этих субстрат овпорождающих уксусно й кислоты, биосинтез от антибиотика сдержив ается. Тормозящий эффек т arsenite на эритромицин биоси нтезаподавляется в зна чительной степенине то лько путем добавления н атрия ацетати propionate но натр ия формате. Этот факт св идетельствует о том, чт о в соответствии сАктив ные эквиваленте (e. g. formaldehyde)тес но связана с биосинтеза эритромицин. В экспери ния осуществляется с пр омытым мицелия anoxidative биосинтеза acetylmethylcarbinol от свободного ацета льдегид Только была про демонстрирована. В отли чие отокисления ацетал ьдегид, окислениеот succinate не мешаетЭти результаты ещ е раз отметить важность уксусной кислоты в каче стве основных центральн ыхпромежуточных от эрит ромицин биосинтезаРоль пропионовая и муравьина якислот (и их возможные metabolically Активные эквиваленте) и метаболические услови я и отношения эритромици нбиосинтеза обсуждаютс я.     

The early evolution of the mega‐diverse genus Begonia (Begoniaceae) inferred from organelle DNA phylogenies

Begonia L. is one of the largest flowering plant genera, a ubiquitous component of many tropical forests and an economically important ornamental plant. In the present study, we address the early evolution of Begonia by generating molecular phylogenies from approximately 7000 bases of chloroplast DNA and approximately 6000 bases of mitochondrial DNA for each of 30 exemplar Begonia species. Broadscale biogeographic patterns found in the phylogenies, together with previously estimated divergence dates, indicated that extant Begonia lineages first diversified in Africa and then subsequently in America and Asia. The phylogenies also revealed that the closest African relatives of the American and Asian Begonia are seasonally‐adapted species. Moderate to strong incongruence between the phylogenies suggested that they differ genealogically. These differences could have been the result of either interspecific hybridization and/or incomplete lineage sorting. The results obtained in the present study provide a much needed genus‐wide framework for future evolutionary studies of this exceptionally diverse tropical genus. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 243–250.