Showing papers on "Primate published in 2008"

A voice region in the monkey brain

Abstract: For vocal animals, recognizing species-specific vocalizations is important for survival and social interactions. In humans, a voice region has been identified that is sensitive to human voices and vocalizations. As this region also strongly responds to speech, it is unclear whether it is tightly associated with linguistic processing and is thus unique to humans. Using functional magnetic resonance imaging of macaque monkeys (Old World primates, Macaca mulatta) we discovered a high-level auditory region that prefers species-specific vocalizations over other vocalizations and sounds. This region not only showed sensitivity to the 'voice' of the species, but also to the vocal identify of conspecific individuals. The monkey voice region is located on the superior-temporal plane and belongs to an anterior auditory 'what' pathway. These results establish functional relationships with the human voice region and support the notion that, for different primate species, the anterior temporal regions of the brain are adapted for recognizing communication signals from conspecifics.

Primate color vision: A comparative perspective

Abstract: Thirty years ago virtually everything known about primate color vision derived from psychophysical studies of normal and color-defective humans and from physiological investigations of the visual system of the macaque monkey, the most popular of human surrogates for this purpose. The years since have witnessed much progress toward the goal of understanding this remarkable feature of primate vision. Among many advances, investigations focused on naturally occurring variations in color vision in a wide range of nonhuman primate species have proven to be particularly valuable. Results from such studies have been central to our expanding understanding of the interrelationships between opsin genes, cone photopigments, neural organization, and color vision. This work is also yielding valuable insights into the evolution of color vision.

Large-Scale Reorganization in the Somatosensory Cortex and Thalamus after Sensory Loss in Macaque Monkeys

Abstract: Adult brains undergo large-scale plastic changes after peripheral and central injuries. Although it has been shown that both the cortical and thalamic representations can reorganize, uncertainties exist regarding the extent, nature, and time course of changes at each level. We have determined how cortical representations in the somatosensory area 3b and the ventroposterior (VP) nucleus of thalamus are affected by long standing unilateral dorsal column lesions at cervical levels in macaque monkeys. In monkeys with recovery periods of 22-23 months, the intact face inputs expanded into the deafferented hand region of area 3b after complete or partial lesions of the dorsal columns. The expansion of the face region could extend all the way medially into the leg and foot representations. In the same monkeys, similar expansions of the face representation take place in the VP nucleus of the thalamus, indicating that both these processing levels undergo similar reorganizations. The receptive fields of the expanded representations were similar in somatosensory cortex and thalamus. In two monkeys, we determined the extent of the brain reorganization immediately after dorsal column lesions. In these monkeys, the deafferented regions of area 3b and the VP nucleus became unresponsive to the peripheral touch immediately after the lesion. No reorganization was seen in the cortex or the VP nucleus. A comparison of the extents of deafferentation across the monkeys shows that even if the dorsal column lesion is partial, preserving most of the hand representation, it is sufficient to induce an expansion of the face representation.

Rhesus monkeys and humans share common susceptibility genes for age-related macular disease

Abstract: Age-related macular degeneration (AMD), a complex multigenic disorder and the most common cause of vision loss in the elderly, is associated with polymorphisms in the LOC387715/ARMS2 and HTRA1 genes on 10q26. Like humans, macaque monkeys possess a macula and develop age-related macular pathologies including drusen, the phenotypic hallmark of AMD. We genotyped a cohort of 137 unrelated rhesus macaques with and without macular drusen. As in humans, one variant within LOC387715/ARMS2 and one in HTRA1 were significantly associated with affected status. HTRA1 and the predicted LOC387715/ARMS2 gene were both transcribed in rhesus and human retina and retinal pigment epithelium. Among several primate species, orthologous exons for the human LOC387715/ARMS2 gene were present only in Old World monkeys and apes. In functional analyses, the disease-associated HTRA1 polymorphism resulted in a 2-fold increase in gene expression, supporting a role in pathogenesis. These results demonstrate that two genes associated with AMD in humans are also associated with macular disease in rhesus macaques and that one of these genes is specific to higher primates. This is the first evidence that humans and macaques share the same genetic susceptibility factors for a common complex disease.

An Evolutionarily Conserved Sexual Signature in the Primate Brain

Abstract: The question of a potential biological sexual signature in the human brain is a heavily disputed subject. In order to provide further insight into this issue, we used an evolutionary approach to identify genes with sex differences in brain expression level among primates. We reasoned that expression patterns important to uphold key male and female characteristics may be conserved during evolution. We selected cortex for our studies because this specific brain region is responsible for many higher behavioral functions. We compared gene expression profiles in the occipital cortex of male and female humans (Homo sapiens, a great ape) and cynomolgus macaques (Macaca fascicularis, an old world monkey), two catarrhine species that show abundant morphological sexual dimorphism, as well as in common marmosets (Callithrix Jacchus, a new world monkey) which are relatively sexually monomorphic. We identified hundreds of genes with sex-biased expression patterns in humans and macaques, while fewer than ten were differentially expressed between the sexes in marmosets. In primates, a general rule is that many of the morphological and behavioral sexual dimorphisms seen in polygamous species, such as macaques, are typically less pronounced in monogamous species such as the marmosets. Our observations suggest that this correlation may also be reflected in the extent of sex-biased gene expression in the brain. We identified 85 genes with common sex-biased expression, in both human and macaque and 2 genes, X inactivation-specific transcript (XIST) and Heat shock factor binding protein 1 (HSBP1), that were consistently sex-biased in the female direction in human, macaque, and marmoset. These observations imply a conserved signature of sexual gene expression dimorphism in cortex of primates. Further, we found that the coding region of female-biased genes is more evolutionarily constrained compared to the coding region of both male-biased and non sex-biased brain expressed genes. We found genes with conserved sexual gene expression dimorphism in the occipital cortex of humans, cynomolgus macaques, and common marmosets. Genes within sexual expression profiles may underlie important functional differences between the sexes, with possible importance during primate evolution.

Interspecies Transmission of Simian Foamy Virus in a Natural Predator-Prey System

Abstract: Simian foamy viruses (SFV) are ancient retroviruses of primates and have coevolved with their host species for as many as 30 million years. Although humans are not naturally infected with foamy virus, infection is occasionally acquired through interspecies transmission from nonhuman primates. We show that interspecies transmissions occur in a natural hunter-prey system, i.e., between wild chimpanzees and colobus monkeys, both of which harbor their own species-specific strains of SFV. Chimpanzees infected with chimpanzee SFV strains were shown to be coinfected with SFV from colobus monkeys, indicating that apes are susceptible to SFV superinfection, including highly divergent strains from other primate species.

Sleep architecture in unrestrained rhesus monkeys (Macaca mulatta) synchronized to 24-hour light-dark cycles.

Abstract: THE USE OF NONHUMAN PRIMATES AS A MODEL FOR HUMAN SLEEP HAS UNIQUE RELEVANCE TO HUMAN NEUROBIOLOGY. THE CLOSE PHYLOGENETIC relationship and similar diurnal habits of nonhuman primates allow them to fill a gap between sleep studies of rodents or felines and those of humans. The rhesus monkey (Macaca mulatta) was determined to be the best sleep model in a comparison of 13 nonhuman primate species,1 both for its well-defined, human-like sleep organization and for relative ease of husbandry. The rhesus monkey has also been the most extensively used nonhuman primate model for the study of human diseases, including disorders of the nervous system. An extensive knowledge of the physiology of the rhesus monkey also confers an important advantage over the use of other primate species as a model for human sleep. Until recently, studies employing EEG for sleep recordings in rhesus monkeys were necessarily performed using methodological approaches that prevented the expression of normal sleep. For example, potentially confounding manipulations included the need to relocate animals to a novel laboratory setting for recordings, chair restraint and physical tethering of the animals during recording. Although short-term acclimation to the setting was typically (but not always) employed, the animals were nonetheless in an environment unlike their home cages and remained physically restrained for the duration of the sleep recording, forcing the animals to, at a minimum, adopt abnormal sleeping postures. The negative impact of physical restraint on sleep behaviors has been convincingly demonstrated in baboons, which displayed disrupted sleep-wake patterns, unusual drowsiness, and inattentiveness.2 Their sleep patterns also differed from those of animals with externally mounted telemetry that permitted them to move freely in their cages.3 Although no similar comparison of sleep patterns between restrained and unrestrained rhesus monkeys is available, it is known that normal behaviors of rhesus monkeys are markedly affected by chair restraint.4 Restraint induces a number of endocrine changes in rhesus monkeys, including changes in circulating renin, vasopressin, and growth hormone,5 as well as alteration of hemodynamic variables, including cardiac output, blood pressure, and total peripheral resistance.6 Perhaps unsurprisingly then, sleep in restrained rhesus monkeys has shown considerable variability, including marked fragmentation and prolonged bouts of wakefulness during the normal sleep period, suggesting that restraint, novel settings, or other experimental manipulations may have contributed to the inconsistencies seen in prior studies.7–9 Another distinct limitation of most prior rhesus sleep studies has been the relatively short duration of the recording period, which typically consisted of nighttime recordings only, possibly due in part to the limitations of paper polygraph systems. In the present study, sleep recordings of unrestrained rhesus monkeys were made in their home cages using fully implantable biotelemetry transmitters and a computer data collection system, permitting continuous recordings over multiple consecutive days, with battery life lasting up to a year of continuous operation to enable long-term sleep studies. By avoiding novel settings, restraint, backpacks, and other potentially stressful apparatus and manipulations, we anticipated obtaining a more accurate and complete characterization of normal sleep in the rhesus monkey. Specifically, we hypothesized that the rhesus in our study would demonstrate greater sleep consolidation and sleep efficiency (defined by percentage of total time in sleep) during the dark period than previously seen in restrained animals. A better characterization of the undisturbed sleep patterns of rhesus monkeys, particularly where similarities with human sleep could be established, would be an important step in validating the rhesus as a biomedical model of human sleep regulation.

Natural selection in the TLR- related genes in the course of primate evolution

Abstract: The innate immune system constitutes the front line of host defense against pathogens. Toll-like receptors (TLRs) recognize molecules derived from pathogens and play crucial roles in the innate immune system. Here, we provide evidence that the TLR-related genes have come under natural selection pressure in the course of primate evolution. We compared the nucleotide sequences of 16 TLR-related genes, including TLRs (TLR1–10), MYD88, TILAP, TICAM1, TICAM2, MD2, and CD14, among seven primate species. Analysis of the non-synonymous/synonymous substitution ratio revealed the presence of both strictly conserved and rapidly evolving regions in the TLR-related genes. The genomic segments encoding the intracellular Toll/interleukin 1 receptor domains, which exhibited lower rates of non-synonymous substitution, have undergone purifying selection. In contrast, TLR4, which carried a high proportion of non-synonymous substitutions in the part of extracellular domain spanning 200 amino acids, was found to have been the suggestive target of positive Darwinian selection in primate evolution. However, sequence analyses from 25 primate species, including eight hominoids, six Old World monkeys, eight New World monkeys, and three prosimians, showed no evidence that the pressure of positive Darwinian selection has shaped the pattern of sequence variations in TLR4 among New World monkeys and prosimians.

Predation increases acoustic complexity in primate alarm calls

Abstract: According to most accounts, alarm calling in non-human primates is a biologically hardwired behaviour with signallers having little control over the acoustic structure of their calls. In this study, we compared the alarm calling behaviour of two adjacent populations of Diana monkeys at Tai forest (Ivory Coast) and Tiwai Island (Sierra Leone), which differ significantly in predation pressure. At Tai, monkeys regularly interact with two major predators, crowned eagles and leopards, while at Tiwai, monkeys are only hunted by crowned eagles. We monitored the alarm call responses of adult male Diana monkeys to acoustic predator models. We found no site-specific differences in the types of calls given to eagles, leopards and general disturbances, but there were consistent differences in how callers assembled calls into sequences. At Tiwai, males responded to leopards and general disturbances in the same way, while at Tai, males discriminated by giving call sequences that differed in the number of component calls. Responses to eagles were identical at both sites. We concluded that Diana monkeys are predisposed to use their repertoire in context-specific ways, but that ontogenetic experience determines how individual calls are assembled into meaningful sequences.

Predation of wild spider monkeys at La Macarena, Colombia

Abstract: The killing of an adult male spider monkey (Ateles belzebuth ) by a jaguar (Panthera onca) and a predation attempt by a puma (Felis concolor) on an adult female spider monkey have been observed at the CIEM (Centro de Investigaciones Ecologicas La Macarena), La Macarena, Colombia. These incidents occurred directly in front of an observer, even though it is said that predation under direct observation on any type of primate rarely occurs. On the basis of a review of the literature, and the observations reported here, we suggest that jaguars and pumas are likely to be the only significant potential predators on adult spider monkeys, probably because of their large body size.

Towing the party line: territoriality, risky boundaries and male group size in spider monkey fission–fusion societies

Abstract: Spider monkey communities are classic fission–fusion primate societies. I present data suggesting that spider monkeys (Ateles chamek) at Lago Caiman are territorial; adult males traveled further and faster than adult females and subgroup size was significantly higher in boundary areas of the spider monkey territory where intercommunity disputes were observed than in non-boundary areas. I then go on to examine data from 20 Ateles communities distributed across 14 study sites and five species to investigate how a series of demographic, ecological and geographical parameters influence the number of males in a given spider monkey community. Analyses suggest that the number of males is not significantly related to the number of females in a community, the area of the community home range, or the total perimeter length of the community boundary. However, risky boundary perimeter length, or the length of perimeter that directly borders another spider monkey community, explains 88% of observed variations in the number of males in each community. I discuss the results in relation to spider monkey ecology and territoriality, as well as the potential of this relationship for explaining chimpanzee (Pan) behavior given their extremely similar fruit specialist, male philopatry, territoriality and fission–fusion social system. Am. J. Primatol. 70:271–281, 2008. © 2007 Wiley-Liss, Inc.

Aging in Wild Female Lemurs: Sustained Fertility with Increased Infant Mortality

Abstract: Understanding the way prosimian primates age can be helpful in inferring what the ‘basal primate mode’ of senescence may have been. Even though prosimians are known to be long-lived in captivity, re

Postnatal development of disparity sensitivity in visual area 2 (v2) of macaque monkeys.

Abstract: Macaque monkeys do not reliably discriminate binocular depth cues until about 8 wk of age. The neural factors that limit the development of fine depth perception in primates are not known. In adults, binocular depth perception critically depends on detection of relative binocular disparities and the earliest site in the primate visual brain where a substantial proportion of neurons are capable of discriminating relative disparity is visual area 2 (V2). We examined the disparity sensitivity of V2 neurons during the first 8 wk of life in infant monkeys and compared the responses of V2 neurons to those of V1 neurons. We found that the magnitude of response modulation in V2 and V1 neurons as a function of interocular spatial phase disparity was adult-like as early as 2 wk of age. However, the optimal spatial frequency and binocular response rate of these disparity sensitive neurons were more than an octave lower in 2- and 4-wk-old infants than in adults. Consequently, despite the lower variability of neuronal firing in V2 and V1 neurons of infant monkeys, the ability of these neurons to discriminate fine disparity differences was significantly reduced compared with adults. This reduction in disparity sensitivity of V2 and V1 neurons is likely to limit binocular depth perception during the first several weeks of a monkey's life.

Bilateral neurotoxic amygdala lesions in rhesus monkeys (Macaca mulatta): consistent pattern of behavior across different social contexts.

Abstract: Although the amygdala has been repeatedly implicated in normal primate social behavior, great variability exists in the specific social and nonsocial behavioral changes observed in nonhuman primates with bilateral amygdala lesions. One plausible explanation pertains to differences in social context. This study measured the social behavior of amygdala-lesioned and unoperated rhesus monkeys (Macaca mulatta) in 2 contexts. Monkeys interacted in 4-member social groups over 32 test days. They were previously assessed in pairs (N. J. Emery et al., 2001) and were therefore familiar with each other at the beginning of this study. Across the 2 contexts, amygdala lesions produced a highly consistent pattern of social behavior. Operated monkeys engaged in more affiliative social interactions with control partners than did controls. In the course of their interactions, amygdala-lesioned monkeys also displayed an earlier decrease in nervous and fearful personality qualities than did controls. The increased exploration and sexual behavior recorded for amygdala-lesioned monkeys in pairs was not found in the 4-member groups. The authors concluded that the amygdala contributes to social inhibition and that this function transcends various social contexts.

Cerebral amyloid-beta protein accumulation with aging in cotton-top tamarins: a model of early Alzheimer's disease?

Abstract: Alzheimer's disease (AD) is the most common progressive form of dementia in the elderly. Two major neuropathological hallmarks of AD include cerebral deposition of amyloid-beta protein (Aβ) into plaques and blood vessels, and the presence of neurofibrillary tangles in brain. In addition, activated microglia and reactive astrocytes are often associated with plaques and tangles. Numerous other proteins are associated with plaques in human AD brain, including Apo E and ubiquitin. The amyloid precursor protein and its shorter fragment, Aβ, are homologous between humans and non-human primates. Cerebral Aβ deposition has been reported previously for rhesus monkeys, vervets, squirrel monkeys, marmosets, lemurs, cynomologous monkeys, chimpanzees, and orangutans. Here we report, for the first time, age-related neuropathological changes in cotton-top tamarins (CTT, Saguinus oedipus), an endangered non-human primate native to the rainforests of Colombia and Costa Rica. Typical lifespan is 13–14 years of age...

Molecular characterization of the first polyomavirus from a New World primate: squirrel monkey polyomavirus.

Abstract: DNA samples from a variety of New World monkeys were screened by using a broad-spectrum PCR targeting the VP1 gene of polyomaviruses. This resulted in the characterization of the first polyomavirus from a New World primate. This virus naturally infects squirrel monkeys (Saimiri sp.) and is provisionally named squirrel monkey polyomavirus (SquiPyV). The complete genome of SquiPyV is 5075 bp in length, and encodes the small T and large T antigens and the three structural proteins VP1, VP2 and VP3. Interestingly, the late region also encodes a putative agnoprotein, a feature that it shares with other polyomaviruses from humans, baboons and African green monkeys. Comparison with other polyomaviruses revealed limited sequence similarity to any other polyomavirus, and phylogenetic analysis of the VP1 gene confirmed its uniqueness.

Characterization of the ABO blood group genes in macaques: evidence for convergent evolution.

Abstract: The ABO blood group system is known to act as a major transplantation barrier in primates. Different primate species share the presence of A and B antigens. The polymorphism of the macaque ABO blood group genes was analyzed by cloning and sequencing the exon 7 region. In the case of the rhesus macaque (Macaca mulatto) and cynomolgus monkey (Macaca fascicularis) we were able to identify ABO blood group gene segments which cluster into two lineages, namely: *A/*O1 and *B. In addition allelic variation was observed. The 2 amino acid replacements at positions 266 and 268, which are thought to be crucial for A or B transferase activity, could be confirmed for both macaque species. Comparison of primate sequences shows that A and B reactivity was generated independently from each other in the hominoids and Old World monkey lineages. Hence, the primate A and B blood group genes are subject to convergent evolution.

Fatty acid composition of wild anthropoid primate milks.

Abstract: Fatty acids in milk reflect the interplay between species-specific physiological mechanisms and maternal diet. Anthropoid primates (apes, Old and New World monkeys) vary in patterns of growth and development and dietary strategies. Milk fatty acid profiles also are predicted to vary widely. This study investigates milk fatty acid composition of five wild anthropoids (Alouatta palliata, Callithrix jacchus, Gorilla beringei beringei, Leontopithecus rosalia, Macaca sinica) to test the null hypothesis of a generalized anthropoid milk fatty acid composition. Milk from New and Old World monkeys had significantly more 8:0 and 10:0 than milk from apes. The leaf eating species G. b. beringei and A. paliatta had a significantly higher proportion of milk 18:3n-3, a fatty acid found primarily in plant lipids. Mean percent composition of 22:6n-3 was significantly different among monkeys and apes, but was similar to the lowest reported values for human milk. Mountain gorillas were unique among anthropoids in the high proportion of milk 20:4n-6. This seems to be unrelated to requirements of a larger brain and may instead reflect species-specific metabolic processes or an unknown source of this fatty acid in the mountain gorilla diet.

Stress in cynomolgus monkeys (Macaca fascicularis) subjected to long-distance transport and simulated transport housing conditions

Abstract: The stress associated with transportation of non-human primates used in scientific research is an important but almost unexplored part of laboratory animal husbandry. The procedures and routines concerning transport are not only important for the animals' physical health but also for their mental health as well. The transport stress in cynomolgus monkeys (Macaca fascicularis) was studied in two experiments. In Experiment 1, 25 adult female cynomolgus monkeys were divided into five groups of five animals each that received different diets during the transport phase of the experiment. All animals were transported in conventional single animal transport cages with no visual or tactile contact with conspecifics. The animals were transported by lorry for 24 h at ambient temperatures ranging between 20 degrees C and 35 degrees C. Urine produced before, during and after transport was collected and analysed for cortisol by enzyme-linked immunosorbent assay (ELISA). All monkeys exhibited a significant increase in cortisol excretion per time unit during the transport and on the first day following transport.Although anecdotal reports concerning diet during transport, including the provision of fruits and/or a tranquiliser, was thought likely to influence stress responses, these were not corrobated by the present study. In Experiment 2, behavioural data were collected from 18 cynomolgus macaques before and after transfer from group cages to either single or pair housing, and also before and after a simulated transport, in which the animals were housed in transport cages. The single housed monkeys were confined to single transport cages and the pair housed monkeys were kept in their pairs in double size cages. Both pair housed and singly housed monkeys showed clear behavioural signs of stress soon after their transfer out of their group cages.However, stress-associated behaviours were more prevalent in singly housed animals than in pair housed animals, and these behaviours persisted for a longer time after the simulated transport housing event than in the pair housed monkeys. Our data confirm that the transport of cynomolgus monkeys is stressful and suggest that it would be beneficial for the cynomolgus monkeys to be housed and transported in compatible pairs from the time they leave their group cages at the source country breeding facility until they arrive at their final laboratory destination in the country of use.

Identification of postentry restrictions to Mason-Pfizer monkey virus infection in New World monkey cells.

Abstract: TRIM5α has been shown to be a major postentry determinant of the host range for gammaretroviruses and lentiviruses and, more recently, spumaviruses However, the restrictive potential of TRIM5α against other retroviruses has been largely unexplored We sought to determine whether or not Mason-Pfizer monkey virus (M-PMV), a prototype betaretrovirus isolated from rhesus macaques, was sensitive to restriction by TRIM5α Cell lines from both Old World and New World primate species were screened for their susceptibility to infection by vesicular stomatitis virus G protein pseudotyped M-PMV All of the cell lines tested that were established from Old World primates were found to be susceptible to M-PMV infection However, fibroblasts established from three New World monkey species specifically resisted infection by this virus Exogenously expressing TRIM5α from either tamarin or squirrel monkeys in permissive cell lines resulted in a block to M-PMV infection Restriction in the resistant cell line of spider monkey origin was determined to occur at a postentry stage However, spider monkey TRIM5α expression in permissive cells failed to restrict M-PMV infection, and interference with endogenous TRIM5α in the spider monkey fibroblasts failed to relieve the block to infectivity Our results demonstrate that TRIM5α specificity extends to betaretroviruses and suggest that New World monkeys have evolved additional mechanisms to restrict the infection of at least one primate betaretrovirus

Corpus callosum connections of subdivisions of motor and premotor cortex, and frontal eye field in a prosimian primate, Otolemur garnetti

Abstract: The callosal connections of motor and premotor fields in the frontal cortex of galagos were examined by placing multiple tracers into the primary motor area (M1), dorsal premotor area (PMD), ventral premotor area (PMV), supplementary motor area (SMA), and frontal eye field (FEF) following intracortical microstimulation. Retrogradely labeled neurons in the opposite hemisphere were plotted and superimposed onto brain sections stained with myelin and cytochrome oxidase for architectonic analysis. The main callosal connections of M1 and the caudal portion of PMD (PMDc) were with homotopic sites, and the major callosal connections of the rostral portion of PMD (PMDr), SMA, and FEF were with homotopic sites and adjoining cortex in the frontal lobe. In addition, M1 forelimb representation had sparse callosal connections, whereas M1 trunk and face representations, as well as the premotor areas, had dense callosal connections. The sparse interhemispheric connections of the forelimb sector of M1 suggests that the control of each forelimb is largely from the contralateral M1 in galagos, as in other primates.

Duration of Binocular Decorrelation Predicts the Severity of Latent (Fusion Maldevelopment) Nystagmus in Strabismic Macaque Monkeys

Abstract: PURPOSE. Infantile esotropia is linked strongly to latent fixation nystagmus (LN) in human infants, but many features of this comorbidity are unknown. The purpose of this study was to determine how the duration of early-onset strabismus (or timeliness of repair) affects the prevalence of LN in a primate model. METHODS. Optical strabismus was created in infant macaques by fitting them with prism goggles on day 1 of life. The goggles were removed after 3 (n = 2), 12 (n = 1) or 24 weeks (n = 3), emulating surgical repair of strabismus in humans at 3, 12, and 24 months of age, respectively. Eye movements were recorded by using binocular search coils. RESULTS. Each animal in the 12- and 24-week groups exhibited LN and manifest LN, normal spatial vision (no amblyopia), and constant esotropia. The 3-week duration monkeys had stable fixation (no LN) and normal alignment indistinguishable from control animals. In affected monkeys, the longer the duration of binocular decorrelation, the greater the LN: mean slow-phase eye velocity (SPEV) in the 24-week animals was three times greater than that in the 12-week monkey (P = 0.03); mean LN intensity in the 24-week monkeys was three times greater than that in the 12-week monkey (P = 0.03). CONCLUSIONS. Binocular decorrelation in primates during an early period of fusion development causes permanent gaze instability when the duration exceeds the equivalent of 3 months in humans. These findings support the conclusion that early correction of infantile strabismus promotes normal development of cerebral gaze-holding pathways.

Chimerism, point mutation, and truncation dramatically transformed mast cell δ-tryptases during primate evolution

Abstract: Background Tryptases are serine peptidases stored in mast cell granules. Rodents express 2 soluble tryptases, mast cell proteases (MCPs) 6 and 7. Human α- and β-tryptases are orthologs of MCP-6. However, much of the ancestral MCP-7 ortholog was replaced by parts of other tryptases, creating chimeric δ-tryptase. Human δ-tryptase's limited activity is hypothesized to be due to truncation and processing mutations. Objective We sought to probe the origins and consequences of mutations in primate δ-tryptases. Methods Prosimian (lemur), monkey (macaque), great ape (orangutan, gorilla, and chimpanzee), and human δ-tryptase genes were identified by means of data mining and genomic sequencing. Resulting genes were analyzed phylogenetically and structurally. Results The seminal conversion event generating the δ-tryptase chimera occurred early because all primates studied contain δ-tryptase genes. Truncation, resulting from a nonsense mutation of Trp206, occurred much later, after orangutans and other great apes last shared an ancestor. The Arg-3Gln propeptide mutation occurred most recently, being present in humans and chimpanzees but not in other primates. Surprisingly, the major active tryptase in monkeys is full-length δ-tryptase, not β-tryptase, which is the main active tryptase in human subjects. Models of macaque δ-tryptase reveal that the segment truncated in human subjects contains antiparallel β-strands coursing through the substrate-binding cleft, accounting for truncation's drastic effect on activity. Conclusions Transformations in the ancestral MCP-7–like gene during primate evolution caused dramatic variations in function. Although δ-tryptases are nearly inactive in humans, they are active and dominant in monkeys.

Serologic evidence for novel poxvirus in endangered red Colobus monkeys, Western Uganda.

Abstract: Enzyme-linked immunosorbent assay, Western blot, and virus neutralization assays indicated that red colobus monkeys in Kibale National Park, western Uganda, had antibodies to a virus that was similar, but not identical, to known orthopoxviruses The presence of a novel poxvirus in this endangered primate raises public health and conservation concerns

Evolution and development of the strepsirrhine primate skull

Abstract: Since Haeckel (1866), the evolutionary modification of ontogeny has been recognized as an important source of morphological innovation. Due to recent advances in developmental genetics and phenotypic analysis, evolutionary developmental (evo-devo) studies have regained considerable interest and led to fundamental changes in our understanding of how ontogeny and phylogeny are related. This thesis investigates the relationship between ontogeny and phylogeny in strepsirrhine primates. The suborder Strepsirrhini, which comprises galagos, lorises and Malagasy lemurs, is thought to have retained most of the ancestral primate condition (as opposed to the suborder Haplorrhini, which comprises tarsiers and anthropoids). Nevertheless, strepsirrhines are highly diverse in their morphology. Here, the focus is on cranial diversity, which is analyzed from a developmental perspective with a new set of geometric morphometric tools. First, patterns of cranio-mandibular variability in extant adult primates are analyzed. Taking into account the phylogenetic constraints applying to the skull morphology permits a quantification of how dietary specialization and activity patterns influence cranio-mandibular morphology in both primates suborders. Also, the skull morphology in strepsirrhines and haplorrhines is clearly distinct, and it is shown here that differences between and within infraorders can be traced back to differences in developmental modes. According to a hypothesis proposed by Beard (1988), “strepsirrhinism” represents the prim- itive condition of the primate skull. This thesis shows that the cranial morphology of the Omomyidae – a basal haplorrhine taxon comprising the genera Rooneyia, Necrolemur and Microchoerus – is closer to that of extant strepsirrhines than to that of haplorrhines, while the cranial morphology of Tarsius is closer to that of other extant haplorrhines, i.e., the anthropoids. Thus, it is probable that the shift towards a modern haplorrhine morphology occurred in one omomyid lineage, to the exclusion of the three genera mentioned above. New arguments are proposed to support the hypothesis that the cranio-mandibular morphologies of the cheirogaleids and galagids are the least derived from the ancestral condition of toothcombed strepsirrhines. This thesis presents a comparative geometric morphometric analysis of cranio-mandibular development in ten strepsirrhine and two haplorrhine species. Haplorrhines and strepsirrhines differ widely in ontogenetic trajectory direction, length and position. Within the strepsirrhines, divergence between taxon-specific ontogenetic trajectories and allometric grade shifts are more pronounced in lemurs than in lorises. This pattern of evolutionary modification of ontogenetic trajectories is interpreted in the context of the rapid adaptive radiation of lemurs. The last section uses insights obtained from the evolutionary developmental analysis of extant taxa for a comparative analysis of fossil strepsirrhine taxa. The morphologies of extant and extinct strepsirrhines are compared. In particular, the morphology of the skull is well known from two adapiform subfamilies, Adapinae and Notharctinae. Among the adapines, a size increase has occurred in the Leptadapis lineage via a shift in allometric grade, which suggests phyletic gigantism in this genus. Adapiforms exhibit longer ontogenetic trajectories than extant strepsirrhines. A trend toward a shortening of ontogenetic trajectories has occurred in the evolutionary history of strepsirrhines. This can be related to a context of general increase in encephalization within this lineage.

Evolution of the hepcidin gene in primates.

Abstract: Hepcidin/LEAP-1 is an iron regulatory hormone originally identified as an antimicrobial peptide. As part of a systematic analysis of the evolution of host defense peptides in primates, we have sequenced the orthologous gene from 14 species of non-human primates. The sequence of the mature peptide is highly conserved amongst all the analyzed species, being identical to the human one in great apes and gibbons, with a single residue conservative variation in Old-World monkeys and with few substitutions in New-World monkeys. Our analysis indicates that hepcidin's role as a regulatory hormone, which involves interaction with a conserved receptor (ferroportin), may result in conservation over most of its sequence, with the exception of the stretch between residues 15 and 18, which in New-World monkeys (as well as in other mammals) shows a significant variation, possibly indicating that this structural region is involved in other functions.

Primate Reproductive Aging: From Lemurs to Humans

Abstract: The scope of data now available for primates from long-term field and captive studies has opened up exciting possibilities for investigating age-related patterns of reproduction Valuable information on the aging process can be gleaned through broad cross-taxonomic comparative studies that include lemurs, monkeys, apes and humans Thus, across all taxa discussed in this volume, female reproduction was found to be complex and dynamic, affected by the interplay of multiple exogenous and endogenous factors Throughout their lives, females differ in their individual reproductive output As they age, a period of reproductive instability is common among female primates and perimenopausal- like hormonal changes have been noted in many species Available data from lemurs and callitrichids indicate that at least in some species, age-related declines in reproduction are manifested as diminished success of females to rear their young to weaning age Few data are available for New World primates, but the same observation holds true for Old World monkey females, who also are characterized by declines in sexual activity and decreased birth rates In apes, captive data suggest the presence of an appreciable postreproductive lifespan but this has not been confirmed in the wild Menopause may be manifested as an evolutionary continuum across primate taxa with the potential for an extended postreproductive lifespan evident in cercopithecines and apes