Showing papers on "Primate published in 2007"

Evolutionary and biomedical insights from the rhesus macaque genome

Abstract: The rhesus macaque (Macaca mulatta) is an abundant primate species that diverged from the ancestors of Homo sapiens about 25 million years ago. Because they are genetically and physiologically similar to humans, rhesus monkeys are the most widely used nonhuman primate in basic and applied biomedical research. We determined the genome sequence of an Indian-origin Macaca mulatta female and compared the data with chimpanzees and humans to reveal the structure of ancestral primate genomes and to identify evidence for positive selection and lineage-specific expansions and contractions of gene families. A comparison of sequences from individual animals was used to investigate their underlying genetic diversity. The complete description of the macaque genome blueprint enhances the utility of this animal model for biomedical research and improves our understanding of the basic biology of the species.

Route-based travel and shared routes in sympatric spider and woolly monkeys: cognitive and evolutionary implications.

Abstract: Many wild primates occupy large home ranges and travel long distances each day. Navigating these ranges to find sufficient food presents a substantial cognitive challenge, but we are still far from understanding either how primates represent spatial information mentally or how they use this information to navigate under natural conditions. In the course of a long-term socioecological study, we investigated and compared the travel paths of sympatric spider monkeys (Ateles belzebuth) and woolly monkeys (Lagothrix poeppigii) in Amazonian Ecuador. During several field seasons spanning an 8-year period, we followed focal individuals or groups of both species continuously for periods of multiple days and mapped their travel paths in detail. We found that both primates typically traveled through their home ranges following repeatedly used paths, or "routes". Many of these routes were common to both species and were stable across study years. Several important routes appeared to be associated with distinct topographic features (e.g., ridgetops), which may constitute easily recognized landmarks useful for spatial navigation. The majority of all location records for both species fell along or near identified routes, as did most of the trees used for fruit feeding. Our results provide strong support for the idea that both woolly and spider monkey use route-based mental maps similar to those proposed by Poucet (Psychol Rev 100:163-182, 1993). We suggest that rather than remembering the specific locations of thousands of individual feeding trees and their phenological schedules, spider and woolly monkeys could nonetheless forage efficiently by committing to memory a series of route segments that, when followed, bring them into contact with many potential feeding sources for monitoring or visitation. Furthermore, because swallowed and defecated seeds are deposited in greater frequency along routes, the repeated use of particular travel paths over generations could profoundly influence the structure and composition of tropical forests, raising the intriguing possibility that these and other primate frugivores are active participants in constructing their own ecological niches. Building upon the insights of Byrne (Q J Exp Psychol 31:147-154, 1979, Normality and pathology in cognitive functions. Academic, London, pp 239-264, 1982) and Milton (The foraging strategy of howler monkeys: a study in primate economics. Columbia University Press, New York, 1980, On the move: how and why animals travel in groups. University of Chicago Press, Chicago, pp 375-417, 2000), our results highlight the likely general importance of route-based travel in the memory and foraging strategies of nonhuman primates.

Interactive effects of age and estrogen on cognition and pyramidal neurons in monkey prefrontal cortex

Abstract: We previously reported that long-term cyclic estrogen (E) treatment reverses age-related impairment of cognitive function mediated by the dorsolateral prefrontal cortex (dlPFC) in ovariectomized (OVX) female rhesus monkeys, and that E induces a corresponding increase in spine density in layer III dlPFC pyramidal neurons. We have now investigated the effects of the same E treatment in young adult females. In contrast to the results for aged monkeys, E treatment failed to enhance dlPFC-dependent task performance relative to vehicle control values (group young OVX+Veh) but nonetheless led to a robust increase in spine density. This response was accompanied by a decline in dendritic length, however, such that the total number of spines per neuron was equivalent in young OVX+Veh and OVX+E groups. Robust effects of chronological age, independent of ovarian hormone status, were also observed, comprising significant age-related declines in dendritic length and spine density, with a preferential decrease in small spines in the aged groups. Notably, the spine effects were partially reversed by cyclic E administration, although young OVX+Veh monkeys still had a higher complement of small spines than did aged E treated monkeys. In summary, layer III pyramidal neurons in the dlPFC are sensitive to ovarian hormone status in both young and aged monkeys, but these effects are not entirely equivalent across age groups. The results also suggest that the cognitive benefit of E treatment in aged monkeys is mediated by enabling synaptic plasticity through a cyclical increase in small, highly plastic dendritic spines in the primate dlPFC.

Parallel Evolution of Cortical Areas Involved in Skilled Hand Use

Abstract: Dexterous hands, used to manipulate food, tools, and other objects, are one of the hallmarks of primate evolution. However, the neural substrate of fine manual control necessary for these behaviors remains unclear. Here, we describe the functional organization of parietal cortical areas 2 and 5 in the cebus monkey. Whereas other New World monkeys can be quite dexterous, and possess a poorly developed area 5, cebus monkeys are the only New World primate known to use a precision grip, and thus have an extended repertoire of manual behaviors. Unlike other New World Monkeys, but much like the macaque monkey, cebus monkeys possess a proprioceptive cortical area 2 and a well developed area 5, which is associated with motor planning and the generation of internal body coordinates necessary for visually guided reaching, grasping, and manipulation. The similarity of these fields in cebus monkeys and distantly related macaque monkeys with similar manual abilities indicates that the range of cortical organizations that can emerge in primates is constrained, and those that emerge are the result of highly conserved developmental mechanisms that shape the boundaries and topographic organizations of cortical areas.

Primate anti-predator strategies

Abstract: Predation Theory.- Predation and Primate Cognitive Evolution.- Predation on Primates: A Biogeographical Analysis.- Anti-Predator Strategies of Nocturnal Primates.- Primates and Other Prey in the Seasonally Variable Diet of Cryptoprocta ferox in the Dry Deciduous Forest of Western Madagascar.- Predation on Lemurs in the Rainforest of Madagascar by Multiple Predator Species: Observations and Experiments.- Predation, Communication, and Cognition in Lemurs.- A Consideration of Leaping Locomotion as a Means of Predator Avoidance in Prosimian Primates.- Anti-Predator Strategies of Cathemeral Primates: Dealing with Predators of the Day and the Night.- Moonlight and Behavior in Nocturnal and Cathemeral Primates, Especially Lepilemur leucopus: Illuminating Possible Anti-Predator Efforts.- A Comparison of Calling Patterns in Two Nocturnal Primates, Otolemur crassicaudatus and Galago moholi as a Guide to Predation Risk.- Predator Defense by Slender Lorises and Pottos.- The Response of Spectral Tarsiers Toward Avian and Terrestrial Predators.- Talking Defensively, a Dual Use for the Brachial Gland Exudate of Slow and Pygmy Lorises.- Anti-Predator Strategies of Non-Nocturnal Primates.- Anti-Predator Strategies in a Diurnal Prosimian, the Ring-Tailed Lemur (Lemur catta), at the Beza Mahafaly Special Reserve, Madagascar.- Howler Monkeys and Harpy Eagles: A Communication Arms Race.- Effects of Habitat Structure on Perceived Risk of Predation and Anti-Predator Behavior of Vervet (Cercopithecus aethiops) and Patas (Erythrocebus patas) Monkeys.- Predation Risk and Habitat Use in Chacma Baboons (Papio hamadryas ursinus).- Reconstructing Hominin Interactions with Mammalian Carnivores (6.0-1.8 Ma).

PRIMATE ORIGINS: Adaptations and evolution

Abstract: Supraordinal Relationships of Primates and Their Time of Origin.- A Molecular Classification for the Living Orders of Placental Mammals and the Phylogenetic Placement of Primates.- New Light on the Dates of Primate Origins and Divergence.- The Postcranial Morphology of Ptilocercus lowii (Scandentia, Tupaiidae) and its Implications for Primate Supraordinal Relationships.- Primate Origins: A Reappraisal of Historical Data Favoring Tupaiid Affinities.- Primate Taxonomy, Plesiadapiforms, and Approaches to Primate Origins.- Adaptations and Evolution of the Cranium.- Jaw-Muscle Function and the Origin of Primates.- Were Basal Primates Nocturnal? Evidence From Eye and Orbit Shape.- Oculomotor Stability and the Functions of the Postorbital Bar and Septum.- Primate Origins and the Function of the Circumorbital Region: What's Load Got to Do with It?.- Adaptations and Evolution of the Postcranium.- Origins of Grasping and Locomotor Adaptations in Primates: Comparative and Experimental Approaches Using an Opossum Model.- Evolvability, Limb Morphology, and Primate Origins.- Primate Gaits and Primate Origins.- Morphological Correlates of Forelimb Protraction in Quadrupedal Primates.- Ancestral Locomotor Modes, Placental Mammals, and the Origin of Euprimates: Lessons From History.- The Postcranial Morphotype of Primates.- New Skeletons of Paleocene-Eocene Plesiadapiformes: A Diversity of Arboreal Positional Behaviors in Early Primates.- Adaptations and Evolution of the Brain, Behavior, Physiology, and Ecology.- Start Small and Live Slow: Encephalization, Body Size, and Life History Strategies in Primate Origins and Evolution.- Evolutionary Specializations of Primate Brain Systems.- New Views on the Origin of Primate Social Organization.- Primate Bioenergetics: An Evolutionary Perspective.- Episodic Molecular Evolution of Some Protein Hormones in Primates and Its Implications for Primate Adaptation.- Parallelisms Among Primates and Possums.- Perspectives on Primate Color Vision.

The evolution of hemispheric specialization in primates

Abstract: 1) Evaluating Genetic and Non-Genetic Models of Handedness in Non-human Primates - William D. Hopkins, 2) Great Ape Handedness - Richard Byre 3) A Comparison of Laterality in Primates and Non-Primates - Leslie Rogers 4) Prosimian functional laterality - Sheree Watson & Jeanette Ward 5) Neuroanatomical Asymmetries in Non-Human Primates - Claudio Cantalupo 6) The Influence of Prenatal Hormones on the Development of Laterality in Monkeys - Greg Westergaard 7) Evolution and Genetics of Handedness in Humans - Michael Corballis 8) Laterality and Cognition in Split-Brain Monkeys - Charles Hamilton & Betty Vermiere 9) Grip morphology and Hand Use in Primates - Marianne Christel 10) Postural Origins of Laterality Revisited. - Peter MacNeilage 11) Handedness in New World Monkeys with Special Reference to Capuchin monkeys - Giovanni Spinozzi 12) Asymmetries in Facial Expressions and Emotions in Primates - Lisa Parr & Samuel Fernanadez-Carriba 13) Morphological Asymmetries in Early Hominids - Ralph Holloway 14) Brain Asymmetries in Primates as Revealed from Endocasts - Dean Falk 15) Evolution of the Corpus Callosum From a Comparative Primate Perspective - Jim Rilling 16) The Development of Hemispheric Specialization in Human and Nonhuman Primates - Kim Bard

Dietary restriction in aging nonhuman primates.

Abstract: Dietary restriction (DR) has been shown to benefit health and longevity in a wide variety of species, although most have maximal life spans of only a few years. In 1987, the National Institute on Aging began the first well-controlled long-term study in a species with a considerably longer life span and a closer physiology to humans. Using rhesus monkeys (Macaca mulatta), an extensive array of physiological measures have been conducted in both males and females to evaluate the effects of DR. Monkeys benefit from DR with a lower body weight, body fat, blood glucose and thus are at lower risk for developing diabetes. Changes in several endocrine measures indicate an altered hormonal axis; however, circadian patterns and timing relative to the onset of DR can obscure the differences. Despite the caloric deficit, female monkeys are not reproductively compromised, and both males and females may benefit immunologically. There remains much to be learned from this model of DR including whether long-term DR will increase life span in a primate species.

Monkeys of the Tai Forest: An African Primate Community

Abstract: 1: The monkeys of the Tai Forest: an introduction W. S. McGraw and K. Zuberbuhler, Part I. Social Behavior: 2. The social system of guenons P. Buzzard and W .Eckardt 3: How small-scale differences in food competition lead to different social systems in three closely related sympatric colobines A. H. Korstjens, K. Bergman, C.Deffernez, M. Krebs, E. C. Nijssen, BAM van Oirschot, C Paukert, E. P. Schippers 4. The structure of social relationships among sooty mangabeys in Tai F. Range, T. Forderer, Y. Meystre, C. Benetton, and C. Fruteau Part II. Anti-Predation Strategies: 5. Interactions between leopard and monkeys K. Zuberbuhler and D. Jenny 6. Interactions between red colobus and chimpanzees R. Bshary 7. Interactions between African crowned eagles and their primate prey community S. Shultz and S. Thomsett 8. Semantic information in alarm calls K. Zuberbuhler Part III. Habitat Use: 9. Positional behavior and habitat use of Tai Forest monkeys W. S. McGraw Part IV. Conservation: 10. Can monkey behavior be used as an indicator for poaching pressure? A case study of the Diana guenon (Cercopithecus diana) and the western red colobus (Procolobus badius) I. Kone and J. Refisch 11. Vulnerability and conservation of the Tai Forest monkeys W. S. McGraw.

Primate Gaits and Primate Origins

Abstract: The order Primates in the strict sense—Euprimates or primates of modern aspect—is defined by a familiar suite of synapomorphies. Some of these may represent adaptively neutral contingencies (for example, the formation of the auditory bulla by an outgrowth from the petrosal, rather than by a separate entotympanic bone). However, others appear to be telling us things about the basal adaptations of the order. Compared to primitive placental mammals, primates have a reduced sense of smell and an enhanced sense of vision. primate eyes point forward and are encircled by a ring of bone. The first toes of primates are stout, divergent grasping organs. All primates have reduced, flattened claws on the first toe, and most of them have them on the other digits as well. The adaptive meaning and origins of some of these morphological synapomorphies of the primate order are discussed in other chapters of this book. One behavioral synapomorphy of primates, which has received less attention in discussions of primate origins, is their distinctive walking gait. When

Predation, Communication, and Cognition in Lemurs

Abstract: Predation represents an important selective force shaping the evolution of primate behavior. Primates confronted with predators have evolved various strategies to minimize the probability of being eaten. Predation risk and hunting styles of predators should have selected for communicative and cognitive abilities linked to socioecology and life history. As studies on several socially cohesive mammals indicate, the study of anti-predator behavior represents an important tool for gaining insight into cognition, e.g., to understand how animals classify objects and events in the world around them (e.g., marmots: Blumstein, 1999; vervet monkeys: Seyfarth et al., 1980; Diana monkeys: Zuberbuhler, 2000; suricates: Manser et al., 2002).

Degeneration of the olfactory guanylyl cyclase D gene during primate evolution.

Abstract: Background The mammalian olfactory system consists of several subsystems that detect specific sets of chemical cues and underlie a variety of behavioral responses. Within the main olfactory epithelium at least three distinct types of chemosensory neurons can be defined by their expression of unique sets of signal transduction components. In rodents, one set of neurons expresses the olfactory-specific guanylyl cyclase (GC)-D gene (Gucy2d, guanylyl cyclase 2d) and other cell-type specific molecules. GC-D-positive neurons project their axons to a small group of atypical “necklace” glomeruli in the olfactory bulb, some of which are activated in response to suckling in neonatal rodents and to atmospheric CO2 in adult mice. Because GC-D is a pseudogene in humans, signaling through this system appears to have been lost at some point in primate evolution. Principal Findings Here we used a combination of bioinformatic analysis of trace-archive and genome-assembly data and sequencing of PCR-amplified genomic DNA to determine when during primate evolution the functional gene was lost. Our analysis reveals that GC-D is a pseudogene in a large number of primate species, including apes, Old World and New World monkeys and tarsier. In contrast, the gene appears intact and has evolved under purifying selection in mouse, rat, dog, lemur and bushbaby. Conclusions These data suggest that signaling through GC-D-expressing cells was probably compromised more than 40 million years ago, prior to the divergence of New World monkeys from Old World monkeys and apes, and thus cannot be involved in chemosensation in most primates.

Primate abundance along five transect lines at Ngogo, Kibale National Park, Uganda.

Abstract: Using the line transect methods, I studied the primate density at Ngogo, Kibale National Park, Uganda for 18 months. Comparisons with other studies show that the population of red colobus monkeys (Procolobus rufomitratus) and blue monkeys (Cercopithecus mitis) is declining, whereas the populations of black-and-white colobus (Colobus guereza), red-tailed monkeys (Cercopithecus ascanius), grey-cheeked mangabeys (Lophocebus albigena), baboons (Papio anubis), and chimpanzees (Pan troglodytes) remain constant or slightly increase. In this paper, I compare data on density from this study to data from previous and recent censuses at Ngogo and with data from other sites in the Kibale forest to examine the stability of primate populations. Furthermore, I test the hypothesis that the changes in red colobus and blue monkey density are due to changes in the forest structure and abundance of their most selected feeding trees, and show that changes in forest composition cannot account for changes in their red colobus abundance, but that hunting by chimpanzees provides a reasonable explanation. Am. J. Primatol. 69:1030–1044, 2007. © 2007 Wiley-Liss, Inc.

Primate Brain Evolution in Phylogenetic Context

Abstract: The order Primates is the group of mammals that includes the hominoids (apes and humans), Old World monkeys, New World monkeys, tarsiers, lemurs, lorises, and bush babies. Enormous progress has been made over the past three decades in understanding the relationships of primates to other mammals, the relationships among primate groups, and the adaptive origins of primates and of primate subgroups. Several lines of evidence indicate that primates belong to a higher-order grouping of mammals, the Archonta, that includes at least tree shrews and flying lemurs. Primates probably originated as a group of small, nocturnally active animals, evolving grasping extremities and close-set, forward-facing eyes to locomote and feed in the fine terminal branches of tree. The origin of anthropoid primates (New World monkeys, Old World monkeys, and hominoids) was marked by a shift to diurnality and the evolution of a retinal fovea for enhanced visual acuity, followed by increased body size and the advent of more complex forms of social organization Primate brain evolution was marked by changes at many levels of structural organization. Brain size increased early in primate evolution, with expansion of the neocortex and the addition of numerous new cortical sensory areas and new systems of interconnections between areas. Also, primates evolved new areas in higher-order cortical regions such as posterior parietal, superior temporal sulcal, and dorsolateral prefrontal cortex, and a new thalamic nucleus, the dorsal (medial) pulvinar, which has extensive connections with the higher-order cortex. The evolution of anthropoid primates was accompanied by further increases in brain size, and the appearance of new areas, especially in higher-order and limbic regions, although it is not clear that the addition of new areas accounts for the increased encephalization of anthropoids. Evolutionary changes in primate brain organization were by no means limited to changes in the complement of areas and extrinsic connectivity: numerous changes in the internal laminar and modular organization of cortical areas have been documented, and there is increasing evidence of changes in the morphological and biochemical phenotypes of brain cells.

Development of l-CDB-4022 as a nonsteroidal male oral contraceptive: induction and recovery from severe oligospermia in the adult male cynomolgus monkey (Macaca fascicularis).

Abstract: The present study was undertaken to examine the antispermatogenic effect of l-CDB-4022 in the adult male cynomolgus monkey. Monkeys (four per group) were dosed via nasogastric tube for 7 d with l-CDB-4022 at 12.5 mg/kg.d or vehicle (d 0=first day of dosing). Plasma levels of l-CDB-4022 and its deesterified metabolite were nondetectable prior to treatment and in all vehicle-treated monkeys. Peak levels of l-CDB-4022 and its metabolite were observed at 4 h after dosing with steady-state levels apparent around d 4. Sperm concentration and total sperm per ejaculate were decreased to levels below 1x10(6) sperm/ml or sperm/ejaculate in l-CDB-4022-treated monkeys by d 17 and remained suppressed through wk 6. Sperm motility also declined to 0% for 6 wk. Testicular volume was reduced in l-CDB-4022-treated monkeys through d 21. The left testis and epididymis were removed from all monkeys on d 24. At this time, the most mature germ cells in the seminiferous tubules of testes from l-CDB-4022-treated monkeys were either spermatocytes or round spermatids. Immature germ cells, but not mature sperm, were found in the efferent ducts and collapsed epididymal lumen of l-CDB-4022-treated monkeys. A steady recovery in sperm motility, concentration, and total sperm per ejaculate was observed in l-CDB-4022-treated monkeys such that these parameters were not different from those of vehicle-treated monkeys by wk 16. Volume of the remaining testis increased in vehicle- and l-CDB-4022-treated monkeys after hemicastration; however, the increase in l-CDB-4022-treated monkeys was delayed compared with that observed in the vehicle-treated monkeys. The morphology of the remaining testis and epididymis, which were removed on wk 17, was normal. Serum inhibin B levels were increased in l-CDB-4022-treated monkeys during the dosing interval; thereafter serum inhibin B levels declined such that there was no difference between the groups by wk 3. l-CDB-4022 treatment did not affect circulating levels of testosterone, LH, FSH, or estradiol. In conclusion, these data indicate that in the cynomolgus monkey, a representative higher primate, l-CDB-4022 exerts a selective antispermatogenic action, which was reversible under the conditions of this study and thus has potential as a nonhormonal oral male contraceptive.

A comparative analysis of serial ordering in ring-tailed lemurs (Lemur catta).

Abstract: Research over the last 25 years has demonstrated that animals are able to organize sequences in memory and retrieve ordered sequences without language. Qualitative differences have been found between the serial organization of behavior in pigeons and monkeys. Here the authors test serial ordering abilities in ring-tailed lemurs, a strepsirrhine primate whose ancestral lineage diverged from that of monkeys, apes, and humans approximately 63 million years ago. Lemurs’ accuracy and response times were similar to monkeys, thus suggesting that they may share mechanisms for serial organization that dates to a common primate ancestor.

What Fossils Tell Us about the Evolution of the Neocortex

Abstract: Mammalian neocortex became relatively a larger fraction of the brain in mammals as they evolved during the Cenozoic era, the past 65 million years. The evolution of neocorticalization is measured by changes in the ratio of the surface area of neocortex to the surface area of the whole brain. Neocorticalization occurred to different extents in different lineages. The overall increase is evident in the positive slope of the regression of neocortical ratio on geological age. The degree of neocorticalization varied in different taxa, greatest in primates and least in marsupials in the sample measured here. The extent of human neocorticalization is not unique for a primate. At least one monkey, a mangabey (Cercocebus), measured as slightly more neocorticalized although the difference between the human and monkey endocasts in this sample was very small. All of the anthropoid primates, including an australopithecine, were very similar in their measurements. These conclusions are based on measurements in over 100 endocranial casts (endocasts) from many different orders of mammals, including 10 living species.

Intrinsic-Signal Optical Imaging Reveals Cryptic Ocular Dominance Columns in Primary Visual Cortex of New World Owl Monkeys

Abstract: A significant concept in neuroscience is that sensory areas of the neocortex have evolved the remarkable ability to represent a number of stimulus features within the confines of a global map of the sensory periphery. Modularity, the term often used to describe the inhomogeneous nature of the neocortex, is without a doubt an important organizational principle of early sensory areas, such as the primary visual cortex (V1). Ocular dominance columns, one type of module in V1, are found in many primate species as well as in carnivores. Yet, their variable presence in some New World monkey species and complete absence in other species has been enigmatic. Here, we demonstrate that optical imaging reveals the presence of ocular dominance columns in the superficial layers of V1 of owl monkeys (Aotus trivirgatus), even though the geniculate inputs related to each eye are highly overlapping in layer 4. The ocular dominance columns in owl monkeys revealed by optical imaging are circular in appearance. The distance between left eye centers and right eye centers is approximately 650 µm. We find no relationship between ocular dominance centers and other modular organizational features such as orientation pinwheels or the centers of the cytochrome oxidase blobs. These results are significant because they suggest that functional columns may exist in the absence of obvious differences in the distributions of activating inputs and ocular dominance columns may be more widely distributed across mammalian taxa than commonly suggested.

Sequence Variation in the Primate Dopamine Transporter Gene and Its Relationship to Social Dominance

Abstract: Dopaminergic activity differs between socially dominant and subordinate monkeys, and in humans, it correlates significantly with extraversion, a trait analogous to social dominance in monkeys. Furthermore, concentrations of monoamine metabolites within the cerebrospinal fluid are highly heritable. Dopaminergic activity is modulated by the dopamine transporter (DAT), and the gene encoding this transporter is therefore an excellent candidate for studies aiming to identify variants of functional or evolutionary significance. However, the majority of such research has focused exclusively on the human homologue and its most common polymorphism, a functional variable number tandem repeat in the 3' untranslated region. Cross-species comparisons provide valuable insights into genome evolution, speciation, and selection mechanisms and may highlight sites of evolutionary significance. To date, however, no comprehensive studies of the DAT gene have been performed simultaneously on multiple primate species. We therefore characterized sequence variation and extent of linkage disequilibrium (LD) across the DAT genes of cynomolgus macaques (Macaca fascicularis), rhesus macaques (Macaca mulatta), and humans. We identified 2 potentially functional variants, which are associated with social rank in cynomolgus monkeys and which correspond to a putative transcription factor-binding site. Although highly conserved across mammals, the DAT gene differs significantly between humans and macaques in levels of sequence variation and LD structure, with the monkeys displaying up to 3 times more sequence variability and significantly less LD than humans. This suggests that the DAT gene has followed different evolutionary trajectories during primate speciation.

High Diversity in Functional Properties of Melanocortin 1 Receptor (MC1R) in Divergent Primate Species Is More Strongly Associated with Phylogeny than Coat Color

Abstract: We have characterized the biochemical function of the melanocortin 1 receptor (MC1R), a critical regulator of melanin synthesis, from 9 phylogenetically diverse primate species with varying coat colors. There is substantial diversity in melanocyte-stimulating hormone (MSH) binding affinity and basal levels of activity in the cloned MC1Rs. MSH binding was lost independently in lemur and New World monkey lineages, whereas high basal levels of MC1R activity occur in lemurs and some New World monkeys and Old World monkeys. Highest levels of basal activity were found in the MC1R of ruffed lemurs, which have the E94K mutation that leads to constitutive activation in other species. In 3 species (2 lemurs and the howler monkey), we report the novel finding that binding and inhibition of MC1R by agouti signaling protein (ASIP) can occur when MSH binding has been lost, thus enabling continuing regulation of the melanin type via ASIP expression. Together, these findings can explain the previous paradox of a predominantly pheomelanic coat in the red ruffed lemur (Varecia rubra). The presence of a functional, MSH-responsive MC1R in orangutan demonstrates that the mechanism of red hair generation in this ape is different from the prevalent mechanism in European human populations. Overall, we have found unexpected diversity in MC1R function among primates and show that the evolution of the regulatory control of MC1R activity occurs by independent variation of 3 distinct mechanisms: basal MC1R activity, MSH binding and activation, and ASIP binding and inhibition. This diversity of function is broadly associated with primate phylogeny and does not have a simple relation to coat color phenotype within primate clades.

Fissão-fusão em Cebus nigritus : flexibilidade social como estratégia de ocupação de ambientes limitantes

Abstract: NAKAI, E. S. Fission-fusion in Cebus nigritus: social flexibility as occupation strategy in limitants environments. 2007. 97p. Master Thesis Institute of Psychology, University of Sao Paulo, Sao Paulo. The primate order presents a great diversity of social organization, from species considered solitary to those where the individuals of a group remain together all the time. Capuchin monkeys (Cebus spp.) generally live in stable and cohesive groups, without the formation of subgroups. However, their social organization can be more flexible. Two former studies on two populations of Cebus nigritus from the Atlantic Forest suggested the occurrence of subgrouping, but the authors could not conclude whether the observed processes were due to a permanent division of a large group or whether these populations were actually fission-fusion societies. The objective of this study was to investigate whether the capuchin monkey groups of the State Park Carlos Botelho (PECB) can be characterized as a fission-fusion society or subgrouping is a temporary strategy prior to a permanent division of a large group. From January 2003 to March 2006, two social groups were followed, with the adult individuals recognized. Data from other groups were collected in an opportunistic way. To verify whether the group was foraging in a cohesive way or divided in subgroups, a census of the group members was performed at each hour and, and the number of adult males, adult females and juveniles were counted to analyze the composition of the subgroups. In order to evaluate the food availability 153 pitfall traps were distributed along the long home range. Data about behavior (locomotion, rest, foraging and locomotion more foraging) and diet (fruits, invertebrates and leaves) were registered by scan sampling every 5 minutes. The depletion time of fruit sources (FTFS) and the number of individuals that fed together in the same tree (size of feeding subunity) were recorded. All the capuchin monkey groups observed in the PECB were organized as a fission-fusion society, splitting into subgroups of variable size and composition, with preferential associations between pairs of male and female, composition multi-male/multi-female and absence of dominance among females. All these observed characteristics are similar to chimpanzees and neotropical primates which present fissionfusion. The main difference among capuchin monkeys and these species are the sexual dispersion from natal group. In capuchin monkeys the males migrate among groups, while in fission-fusion societies the males are philopatric. In relation to the ecological data, the FTFS and the feeding subunity size had low values for all the capuchin monkey groups, indicating that the fruit sources at PECB are poor quality resources and do not support all group members. There was a relation between subgroup size and pattern of food availability: the largerer and more uniformly distributed the fruit sources the animals were feeding, the larger the subgroup. Therefore, capuchin monkeys at PECB adjust their group size in response to the ecological variations, due to the low fruit availability and thus, this great flexibility allows them to adapt to a new environment and to behave in order to increase their fitness.

Extragroup Copulations Among Brown Howler Monkeys in Southern Brazil

Abstract: Di Bitetti, M. 2001. Food-associated calls in tufted capuchin monkeys (Cebus apella). Doctoral thesis, State University of New York at Stony Brook, New York. Di Bitetti, M. 2003. Food-associated calls of tufted capuchin monkeys (Cebus apella nigritus) are functionally referential signals. Behaviour 140: 565–592. Fichtel, C. and Hammerschmidt, K. 2002. Responses of red-fronted lemurs to experimentally modified alarm calls: Evidence for urgency-based changes in call structure. Ethology 108: 763–777. Fichtel, C. and Kappeler, P. M. 2002. Anti-predator behavior of group-living Malagasy primates: Mixed evidence for a referential alarm call system. Behav. Ecol. Sociobiol. 51: 262–275. Izar, P. 2004. Female social relationships of Cebus apella nigritus in a southeastern Atlantic forest: An analysis through ecological models of primate social evolution. Behaviour 141: 71–99. Maccowan, B., Franceschini, N. V. and Vicino, G. 2001. Age differences and developmental trends in alarm peep responses by squirrel monkeys (Saimiri sciureus). Am. J. Primatol. 53: 19–31. Miller, C. T. and Ghazanfar, A. A. 2002. Meaningful acoustic units in nonhuman primate vocal behavior. In: The Cognitive Animal, C. Allen, M. Bekoff and G. M. Burghard (eds.), pp.265–273. The MIT Press, Cambridge. Oliveira, D. A. G. and Ades, C. 1998. Proximity and grooming interactions as indicators of the social organization of brown howler monkeys (Alouatta fusca clamitans). Neotrop. Primates 6: 115–117. Ottoni, E. B. and Mannu, M. 2001. Semifree-ranging tufted capuchins (Cebus apella) spontaneously use tools to crack open nuts. Int. J. Primatol. 22: 347–358. Robinson, J. G. 1982. Vocal systems regulating withingroup spacing. In: Primate Communication, C. T. Snowdon, C. H. Brown and M. R. Petersen (eds.), pp.94–116. Cambridge University Press, Cambridge, UK. Seyfarth, R. M. 1988. Vocal communication and its relation to language. In: Primate Societies, B. B. Smuts, D. L. Cheney, R. M. Seyfarth, R. W. Wrangham and T. T. Struhsaker (eds.), pp. 440– 451. The University of Chicago Press, Chicago. Seyfarth, R. M., Cheney, D. L. and Marler, P. 1980. Vervet monkey alarm calls: Semantic communication in a freeranging primate. Anim. Behav. 28: 1070–1094. Seyfarth, R. M. and Cheney, D. L. 1986. Vocal development in vervet monkeys. Anim. Behav. 34: 1640–1658. Seyfarth, R. M. and Cheney, D. L. 2003. Meaning and emotion in animal vocalizations. Ann. N.Y. Acad. Sci. 1000: 32–55. Snowdon, C. T. and Pola, Y. V. 1978. Interspecific and intraspecific responses to synthesized pygmy marmoset vocalizations. Anim. Behav. 26: 192–206. Struhsaker, T. T. 1967. Auditory communication among vervet monkeys (Cercopithecus aethiops). In: Social Communication Among Primates, S. A. Altmann (ed.), pp.281– 324. The University of Chicago Press, Chicago. Waser, P. M. 1982. The evolution of male loud calls among mangabeys and baboons. In: Primate Communication, C. T. Snowdon, C. H. Brown and M. R. Petersen (eds.), pp.117–143. Cambridge University Press, New York.

Perspectives on primate color vision.

Abstract: This chapter is an attempt to sketch the evolution of the primate lineage in the broadest possible ecological terms. Inevitably, it is based partly on the ideas of others. At minimum, any novelty that we can offer probably derives from insights gleaned from fieldwork on living primates. From that field backdrop, we extrapolate to other epochs. At maximum, this account is likely to be thought to be completely beyond the bounds of acceptable speculation. For this excess, however, we are unrepentant and hope that at least some of

Secondary sexual coloration and CSF 5-HIAA are correlated in vervet monkeys (Cercopithecus aethiops sabaeus).

Abstract: Background Identifying indirect markers of the physiology or neuroendocrinology of a primate can provide a powerful tool to scientists. Anecdotal descriptions and recent experimental evidence suggests that the colorful sexual skin in adult male vervet monkeys (Cercopithecus aethiops sabaeus) might be sensitive to social changes, including dominance relationships, which could be related to serotonergic activity. The present study examined whether individual differences in scrotal coloration were related to cisternal cerebrospinal fluid concentrations of 5-hydroxyindoleacetic acid (CSF 5-HIAA) in a captive population of vervet monkeys. Results Darkly colored males had relatively higher CSF 5-HIAA concentrations than paler males, and scrotal color hue was also related CSF 5-HIAA concentrations. Conclusions These preliminary data are compatible with the hypothesis that scrotal coloration serves as an indirect marker of serotonergic activity. These findings suggest that color assessments might be useful to consider for study design, as well as for animal welfare and captive management.

Review of mammary gland neoplasia in nonhuman primates.

Abstract: A macaque model of breast cancer in humans has been in development over the past several years by Mark Cline and colleagues at North Carolina College of Veterinary Medicine. Recently the North Carolina group was able to characterize thirty-five mammary gland lesions ranging from ductal hyperplasia to carcinoma in situ and invasive ductlal carcinomas that have occurred in cynomolgus and rhesus macaques at various NIH sponsored primate research centers in the United States [1]. In this model they have demonstrated events similar to those described in human breast cancer, such as upregulation of proliferation markers in mammary duct epithelia, as well as alterations in estrogen and progesterone receptors, growth factor receptors, markers of cell death, and the development of morphologically preneoplastic changes. These workers estimated a lifetime incidence of 6% for mammary gland neoplasia in captive macaques and queried whether breast cancer is underreported in simian primates. They also highlight the morphologic and molecular similarities of breast cancer and humans and macaques. Although still a matter for debate, recent evidence based on mitochondrial DNA suggests humans and cercopithecine old world primates, which includes macaques [2], diverged from a common ancestor 25 million years before present time [3–5]. Based on this relative proximity in the evolutionary time scale, nonhuman primates provide an attractive model for humans because of similarities in anatomy and physiology [6– 8]. With regard to the female reproductive system some of these similarities include a unicornuate uterus, a menstrual cycle and pectoral lobulated ductal-alveolar mammary glands [9–11]. Mammary gland tissue is diffusely distributed in all directions of the subcutis over the pectoral and abdominal muscles, resulting in a barely perceptible enlargement even during lactation. The general architecture and innervation of ducts and glands is similar to the human. An average of 5 to 7 lactiferous ducts emerge at the tip of the nipple. Scattered between these ducts are longitudinally orientated bands of smooth muscle. The thick-walled ducts descend to the base of the nipple and abruptly dilate into a mildly tortuous thin-walled lactiferous sinus, which is fed by dozens of small ducts from the surrounding glandular tissue. In both rhesus monkeys and humans, nerve endings are found at the tip of the nipple, as well as surrounding thick-walled ducts of the nipple, some lactiferous sinuses and some small ducts. The supporting fibrous connective tissue of the mammary gland changes from loosely organized during immaturity to more densely packed swirls in the adult. Among the primate genera studied, extensive data on reproduction has been accumulated from macaques, mainly rhesus (Macaca mulatta) and cynomolgus (Macaca fasicularis) monkeys. Macaques, old world primates of the family Cercopithecidae constitute the largest group of nonhuman primates living in managed colonies. Rhesus monkeys attain menarche at 3 to 5 years old, have

Variation in the ligand binding domains of the CD94/NKG2 family of receptors in the squirrel monkey.

Abstract: Natural killer cells are regulated, in part, by cell surface expression of the inhibitory CD94/NKG2A heterodimer and the activating CD94/NKG2C heterodimer. In the present study, we characterize the CD94/NKG2 family in the squirrel monkey, a New World monkey species. Full-length CD94, NKG2A, and NKG2CE complementary deoxyribonucleic acid molecules were identified in three unrelated squirrel monkeys. Three alternatively spliced forms of CD94 were detected in which part of intron 4 was included in the mature transcript, suggesting evolutionary pressure for changes in the corresponding loop 3 region of the lectin domain in squirrel monkeys. Squirrel monkey NKG2A contains a three-nucleotide indel that results in an additional amino acid in the predicted NKG2A protein compared to NKG2A in other species. This NKG2A insertion tracks to loop five of the lectin domain, as is seen with the recently described marmoset NKG2CE indel. Transmembrane-deleted forms of CD94 and NKG2CE were also expressed in the squirrel monkey. Analysis of full-length squirrel monkey and additional primate CD94/NKG2 sequences demonstrated statistically significant increases in the Ka/Ks ratio in the putative major histocompatibility complex E (MHC-E) binding domain compared to the non-binding domain. Furthermore, positive selection was detected in the MHC-E binding domain of primate NKG2 family members, and purifying selection was detected in the primate CD94 binding domain. Purifying selection was also detected in the nonbinding domains of primate CD94 and NKG2 molecules.