A dramatic rise in obesity has occurred among humans within the last several decades. Little is known about whether similar increases in obesity have occurred in animals inhabiting human-influenced environments. We examined samples collectively consisting of over 20 000 animals from 24 populations (12 divided separately into males and females) of animals representing eight species living with or around humans in industrialized societies. In all populations, the estimated coefficient for the trend of body weight over time was positive (i.e. increasing). The probability of all trends being in the same direction by chance is 1.2 Â 10 27 . Surprisingly, we find that over the past several decades, average mid-life body weights have risen among primates and rodents living in research colonies, as well as among feral rodents and domestic dogs and cats. The consistency of these findings among animals living in varying environments, suggests the intriguing possibility that the aetiology of increasing body weight may involve several as-of-yet unidentified and/or poorly understood factors (e.g. viral pathogens, epigenetic factors). This finding may eventually enhance the discovery and fuller elucidation of other factors that have contributed to the recent rise in obesity rates.

We describe a genome reference of the African green monkey or vervet (Chlorocebus aethiops). This member of the Old World monkey (OWM) superfamily is uniquely valuable for genetic investigations of simian immunodeficiency virus (SIV), for which it is the most abundant natural host species, and of a wide range of health-related phenotypes assessed in Caribbean vervets (C. a. sabaeus), whose numbers have expanded dramatically since Europeans introduced small numbers of their ancestors from West Africa during the colonial era. We use the reference to characterize the genomic relationship between vervets and other primates, the intra-generic phylogeny of vervet subspecies, and genome-wide structural variations of a pedigreed C. a. sabaeus population. Through comparative analyses with human and rhesus macaque, we characterize at high resolution the unique chromosomal fission events that differentiate the vervets and their close relatives from most other catarrhine primates, in whom karyotype is highly conserved. We also provide a summary of transposable elements and contrast these with the rhesus macaque and human. Analysis of sequenced genomes representing each of the main vervet subspecies supports previously hypothesized relationships between these populations, which range across most of sub-Saharan Africa, while uncovering high levels of genetic diversity within each. Sequence-based analyses of major histocompatibility complex (MHC) polymorphisms reveal extremely low diversity in Caribbean C. a. sabaeus vervets, compared to vervets from putatively ancestral West African regions. In the C. a. sabaeus research population, we discover the first structural variations that are, in some cases, predicted to have a deleterious effect; future studies will determine the phenotypic impact of these variations.

Introduction: Nonhuman primates may serve as excellent models of sporadic age-associated brain β-amyloid deposition and Alzheimer’s disease pathologic changes. We examined whether a vervet nonhuman primate model recapitulated pathologic, physiologic, and behavioral features of early Alzheimer’s disease. Methods: Nine middle-aged (mean = 11.2 years) and nine aged (mean = 21.7 years) female vervet/ African green monkeys underwent cerebrospinal fluid collection, gait speed measurement, and neuroimaging before neuropathologic assessment. Results: β-amyloid plaques were identified in all aged vervets and paired helical filament tau immunoreactivity was observed in all animals. Cerebrospinal fluid β-amyloid42 and gait speed correlated negatively with age and plaque density. Greater plaque and paired helical filament tau burden predicted reduced volumes and CMRg in several brain regions. Discussion: We observed a coordinated set of relationships among neuropathologic, cerebrospinal fluid, imaging, and behavioral modalities consistent with early Alzheimer’s disease. Our results support future use of the vervet model to explore disease mechanisms, biomarkers, and novel therapeutic strategies.

Animal and human research suggests that the central serotonin system is involved in the inhibition of impulsive behavior. Two studies were designed to assess this relationship in male vervet monkeys ( Cercopithecus aethiops sabaeus ) using a standardized test of impulsivity in a social context: the Intruder Challenge. In the first study, an index of impulsivity in response to an unfamiliar adult male intruder (including latency to approach and aggressive and assertive interactions) was inversely correlated with levels of the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA) in cisternal cerebrospinal fluid (r ϭ Ϫ 0.33, p Ͻ .01, n ϭ 138). The approach, but not aggressive, component of the Impulsivity Index was the primary contributor to this relationship (partial r ϭ Ϫ 0.27, p Ͻ .01). The second experiment compared responses to the Intruder Challenge after 9 weeks of daily treatment with fluoxetine (2 mg/kg, i.m.) or vehicle. Fluoxetine-treated subjects ( n ϭ 6) had significantly lower Impulsivity Index scores than controls ( n ϭ 12Impulsivity has been proposed as the common denominator in a variety of psychological disorders and sociological conditions that have been associated with indices of low central serotonergic functioning (Linnoila et al. 1993). For example, low levels of the serotonin metabolite, 5-hydroyxindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) have been related to violent suicide attempts, impulsive fire-setting, violent and unprovoked aggression, and early onset alcoholism (Brown et al. 1982;Mann 1999;Virkkunen et al. 1994). Impulsivity and impulsive aggression have also been associated with blunted response to pharmacological challenges with serotonin agonists in personality-disordered and substance abusing men Moeller et al. 1994). Recently, Manuck et al. (1998) reported significant inverse correlations between prolactin response to fenfluramine and measures of impulsivity and aggressiveness in men from a community-based sample. This latter study suggests that psychosocial disorders involving impulsive aggression may represent the extremes of normal dimensions of personality and underlying neurochemistry. NO . 4 Social Impulsivity, 5-HIAA, and Fluoxetine 371A number of models have proposed that the monoaminergic neurotransmitters modulate the expression of basic personality dimensions (Cloninger 1987;Depue et al. 1994;Zuckerman 1996). These models generally agree that dopamine is associated with behavioral activation, and serotonin with behavioral inhibition. For example, Cloninger (1987) links the dopamine system with novelty seeking and serotonin with harm avoidance, while Zuckerman (1996) proposes that impulsive sensation seeking is a joint function of a highly reactive dopaminergic system and a weakly reactive serotonergic system. Empirical research to test the above hypotheses uses a variety of methods to measure impulsivity. Human studies typically use self-report interviews or questionnaires, but the different inventories designed to measure this construct frequ...