Sir2 blocks extreme life-span extension

Sir2 is a conserved deacetylase that modulates life span in yeast, worms, and flies and stress response in mammals. In yeast, Sir2 is required for maintaining replicative life span, and increasing Sir2 dosage can delay replicative aging. We address the role of Sir2 in regulating chronological life span in yeast. Lack of Sir2 along with calorie restriction and/or mutations in the yeast AKT homolog, Sch9, or Ras pathways causes a dramatic chronological life-span extension. Inactivation of Sir2 causes uptake and catabolism of ethanol and upregulation of many stress-resistance and sporulation genes. These changes while sufficient to extend chronological life span in wild-type yeast require severe calorie restriction or additional mutations to extend life span of sir2Delta mutants. Our results demonstrate that effects of SIR2 on chronological life span are opposite to replicatve life span and suggest that the relevant activities of Sir2-like deacetylases may also be complex in higher eukaryotes.     

Differential vulnerability of lambs to coyote predation

Coyote-lamb interactions in 65-ha pastures were observed during a study of Komondor dogs guarding sheep. Vulnerability of lambs to coyote predation was related to total time lambs were exposed to coyotes in the enclosures and total time present in the flock. Lambs were most vulnerable during the first two weeks of exposure (P < 0.001, X² = 49.3), and were somewhat less vulnerable in the next 4 weeks of exposure. If the lambs survived 6 weeks of exposure, their chances of succumbing to predation were small. Lambs were most vulnerable if they were added to an established flock. Orphan lambs were more vulnerable than ewe-reared lambs. Even though the coyotes in this study were persistent in attacking lambs, their success was limited for at least 3 reasons. First, the lambs sometimes refused to run from the coyotes. In addition, they occasionally actively defended themselves by foot-stomping, butting and approaching the coyote. Finally, no lambs were killed while in close proximity to a guardian dog. Based on this study, predation might best be reduced by minimizing introductions of new lambs, and especially orphan lambs, to established flocks, and by using a guardian dog, if possible.     

Chimpanzees using stones to crack open oil palm nuts in Liberia

The use of stone-tools to open palm nuts (Elaeis guineensis) was studied in a group of 16 chimpanzees (Pan troglodytes) released from captivity to a natural island setting in Liberia. The behaviour was started by one female of the group; it then spread to 12 others over periods varying from a few seconds to a few weeks. Nut-cracking soon spread to three other sites, both spontaneously and with human encouragement. Both nuts and tools were carried distances of several hundred meters. Social interaction at cracking sites was rich and varied, ranging from fights over possession of tools to unsolicited sharing of nuts. Nut-crackers showed selectivity in schoosing “good” nuts and varied their methods according to the qualities of the nuts. Individual differences in technique emerged. These are the first detailed behavioural data on palm-nut-cracking, and they show many parallels with nut-cracking of other species by chimpanzees of the Tai Forest, Ivory Coast. This is another example of hammer-stone use from a limited region of West Africa: southeastern Guinea, eastern Liberia, and western Ivory Coast. This suggests limited cultural diffusion of the custom.     

Emergence,propagation or disappearance of novel behavioral patterns in the habituated chimpanzees of Mahale: a review

Each local population of chimpanzees shows cultural variation, but little is known about how behavioral variations first emerge, and how often variants spread to other individuals and then become fixed as a local culture in chimpanzee society. Although field studies of chimpanzees are still too short to answer these questions definitively, it may stimulate further study in various sites to summarize the developments observed over the past 40 years at Mahale, Tanzania. Innovative patterns were operationally defined as new behavioral patterns performed by M group chimpanzees from 1981 onwards. Innovations included patterns of feeding (n = 8), human-directed behavior (n = 3), hygiene behavior (n = 4), maternal carrying of infants (n = 2), courtship (n = 2), play (n = 6), intimidation displays (n = 3), and quasi-grooming (n = 4). Although most patterns were repeated later by other individuals, six patterns were never seen performed by another individual, and eight patterns were performed by one or a few individuals but social transmission was unlikely. Thus, innovation was not rare, but emergence of fashion or establishment of traditions seems to occur rarely in chimpanzee society.     

Identification of Specific Sensory Neuron Populations for Study of Expressed Ion Channels

Sensory neurons transmit signals from various parts of the body to the central nervous system. The soma for these neurons are located in the dorsal root ganglia that line the spinal column. Understanding the receptors and channels expressed by these sensory afferent neurons could lead to novel therapies for disease. The initial step is to identify the specific subset of sensory neurons of interest. Here we describe a method to identify afferent neurons innervating the muscles by retrograde labeling using a fluorescent dye DiI (1,1''-dioctadecyl-3,3,3'',3''-tetramethylindocarbocyanine perchlorate). Understanding the contribution of ion channels to excitation of muscle afferents could help to better control excessive excitability induced by certain disease states such as peripheral vascular disease or heart failure. We used two approaches to identify the voltage dependent ion channels expressed by these neurons, patch clamp electrophysiology and immunocytochemistry. While electrophysiology plus pharmacological blockers can identify functional ion channel types, we used immunocytochemistry to identify channels for which specific blockers were unavailable and to better understand the ion channel distribution pattern in the cell population. These techniques can be applied to other areas of the nervous system to study specific neuronal groups.     

Tool use by wild chimpanzees in feeding upon driver ants

The use of stick tools by wild chimpanzees (Pan troglodytes) to feed upon driver ants (Dorylus (Anomma) nigricans) is described. Observations of this ant dipping were made over five years in the Gombe National Park in western Tanzania. Chimpanzees find the nomadic ant colonies visually, often re-visiting the subterranean nest sites until the ants move on. The nest is opened manually and tools are made from green woody vegetation. The ant dipping sequence is intricate and efficient. The chimpanzee predator uses several positioning strategies to minimise the ants' massed defensive tactics. Average intakes of 17–20 g/feeding session are estimated. It is concluded that ants may constitute a significant chimpanzee dietary component and that the dipping tools and techniques are relatively stereotyped in form.     

Multiple recurrent de novo CNVs, including duplications of the 7q11.23 Williams syndrome region, are strongly associated with autism

We have undertaken a genome-wide analysis of rare copy-number variation (CNV) in 1124 autism spectrum disorder (ASD) families, each comprised of a single proband, unaffected parents, and, in most kindreds, an unaffected sibling. We find significant association of ASD with de novo duplications of 7q11.23, where the reciprocal deletion causes Williams-Beuren syndrome, characterized by a highly social personality. We identify rare recurrent de novo CNVs at five additional regions, including 16p13.2 (encompassing genes USP7 and C16orf72) and Cadherin 13, and implement a rigorous approach to evaluating the statistical significance of these observations. Overall, large de novo CNVs, particularly those encompassing multiple genes, confer substantial risks (OR = 5.6; CI = 2.6-12.0, p = 2.4 × 10(-7)). We estimate there are 130-234 ASD-related CNV regions in the human genome and present compelling evidence, based on cumulative data, for association of rare de novo events at 7q11.23, 15q11.2-13.1, 16p11.2, and Neurexin 1.     

Chimpanzees (Pan troglodytes verus) and their mammalian sympatriates: Mt. Assirik,Niokolo-Koba National Park,Senegal

In intact, mosaic ecosystems, chimpanzees are sympatric with a wide range of other mammals, which may be predators, prey, or competitors. We delve beyond the nominal data of species lists to interval-level data on 35 medium-bodied and large-bodied mammals encountered at a hot, dry, and open field site in far West Africa. Frequency of encounter, habitat where found, and number of individuals encountered are analysed for species for which enough data were accumulated. Further, we compare findings over three periods (1976–1979, 2000, 2012). Species most often encountered were those normally classed as typical savanna forms. Even a crude classification into forest, woodland, and grassland ecotypes yields differences in species likely to meet apes. Comparison of encounter rates over time was surprisingly congruent, although not all species seen in the 1970s survived to the 2000s. Overall, Assirik’s mammalian fauna is comparable to palaeo-faunal guilds sympatric with various extinct hominins.     

Tool use by wild chimpanzees (Pan troglodytes) to obtain termites (Macrotermes herus) in the Mahale Mountains,Tanzania

Wild chimpanzees (Pan troglodytes) used probes made of vegetation to fish for termites (Macrotermes herus) in the Mahale Mountains of western Tanzania. Data on both the artefacts and behavior associated with their use were recorded over a 5-month period. The chimpanzees of one unit group, B Group, were seen four times to use the tools to extract the insects from their mounds. A sample of 290 tools was collected and analyzed in terms of age, seasonality, length, width, class of raw materials, species, methods of making, extent of use, and damage incurred through use. There were differences across groups in tool use in feeding on termites; some could be related to biotic factors, but others appeared to be cultural differences.