Naturally occurring aortic aneurysms in owl monkeys (Aotus spp.).

Spontaneous aortic aneurysms were diagnosed in 22 owl monkeys (Aotus spp.) at necropsy. There were 6 males and 16 females. Clinical findings varied including weight loss, weakness, and lethargy and were not present in all animals. Aortic lesions ranged in size from 2 mm to 3 cm in diameter. Nineteen of the aneurysms were classified histologically as dissecting and three as saccular. Lesions occurred less often in karyotype I monkeys than in karyotype II or III monkeys. The etiopathogenesis of aortic aneurysm in owl monkeys is unknown.     

Susceptibility of owl monkeys to Plasmodium falciparum infection in relation to location of origin, phenotype, and karyotype.

The relationship among geographic origin, phenotype, karyotype, and susceptibility of owl monkeys to 2 strains of Plasmodium falciparum was investigated. Owl monkeys from Columbia and Panama were both susceptible to fatal infections with the Asian FVO (Vietnam-Oak Knoll) strain of P. falciparum. However, when inoculated with the African FUP (Uganda-Palo Alto) strain, most Colombian owl monkeys developed fatal or potentially fatal (bled out with parasitemias of over 25%) infections, but Panamanian monkeys generally survived. Colombian and Panamanian monkeys that spontaneously recovered from malaria infection were phenotypically indistinguishable from those which died. Karyotype analysis revealed that animals considered in this study were either Karyotype II (54 chromosomes) or II (53 chromosomes). Karyotype differences between individual monkeys did not correlate with increased susceptibility or resistance to malaria. Thus, the country of origin of owl monkeys appears to play a more important role in host susceptibility to malaria infection than karyotype.     

Molecular evidence of Y-autosomal translocations in owl monkeys

Probe pDP1007, which contains highly conserved DNA sequences from the sex-determining region of the human Y chromosome, cross-hybridized with owl monkey EcoRI restriction fragments of 1.8 kb and 6.6 kb. Southern transfer analysis of owl monkey (karyotype VI)--rodent somatic cell hybrids localized the 1.8-kb fragment on the owl monkey X chromosome and the 6.6-kb fragment, which is male specific, on chromosome 14/Y. Regional in situ chromosome mapping of pDP1007 revealed specific sites of hybridization: the distal short arm of the X chromosome of karyotypes IV, VI, and VII; the small metacentric Y of karyotype IV; the C-band positive region on the short arm of chromosome 17/Y (karyotype VII); and the C-band positive region on the long arm of chromosome 14/Y (karyotype VI). These molecular findings reinforce cytological evidence that Y-chromosomal material has been transferred to autosomes 14 and 17 in owl monkeys of karyotypes VI and VII, respectively, in which there are no independently segregating Y chromosomes.     

Adult male replacement and subsequent infant care by male and siblings in socially monogamous owl monkeys (<Emphasis Type="Italic">Aotus azarai</Emphasis>)

Owl monkeys (Aotus azarai) are small, territorial, socially monogamous primates that show intense infant care by the adult male in the group. It has been hypothesized that male care may be adaptive because it increases offspring survival and/or reduces the metabolic costs to the female of raising the offspring. Alternatively, males may provide care even when they are not related to the infants to increase future reproductive opportunities. We describe changes in infant care patterns that took place after the eviction of the resident male by a solitary male in an owl monkey population in the Argentinean Chaco. The resident male and mother provided all infant care during the first month of life of the infant, until the male was evicted. During the three-day male replacement event, care of the infant was shared among the mother, a four-year-old sister, and a one-year-old brother. The new male began contributing to infant care soon after entering the group, carrying, and interacting socially with the infant in much the same way as any male regularly does. However, despite receiving biparental care from both the original and new resident males, the infant disappeared at the age of four months and was presumed dead. These are the first reports of care by sibling and by non-putative fathers in wild owl monkeys. Given the significant amount of time that new pairs of owl monkeys spend before reproducing, it is possible that male care in owl monkeys functions as mating effort as much as or more than parenting effort.     

Chromosome assignment of the owl monkey MOS and MYC gene loci

Southern blot hybridizations of rodent x owl monkey hybrid DNAs with human cDNA probes allowed the mapping of the MOS and MYC gene loci to owl monkey chromosome 16 of karyotype VI (2n = 49 male/50 female) and to the homologous chromosome 15 of karyotype V (2n = 46). Synteny of MOS and MYC gene loci in both man and owl monkey suggests this chromosome segment's conservation in primates, contrasting with its disruption in the mouse.     

Reproduction of the owl monkey (Aotus spp.) in captivity

Abstract: The reproduction performance of captive owl monkeys, a breed used extensively in biomedical research, was observed at the Battelle Primate Facility (BPF). The colony grew through captive breeding, imports from the Peruvian Primatological Project, and others to a peak size of 730. It included seven karyotypes of Aotus sp. Results showed that owl monkeys can breed successfully in a laboratory in numbers sufficient to sustain modest research programs. Reproductive success increases when pairs are compatible, of the same karyotype, and stabilized; however, mated pairs of different karyotype are also productive. Under conditions of controlled lighting and heating, owl monkeys at BPF showed no birth peak nor birth season.     

Cholelithiasis in owl monkeys: seven cases

Spontaneous cholelithiasis was found in seven owl monkeys (Aotus spp.) at necropsy. There were four male and three female animals. Antemortem clinicopathologic findings included weight loss, anemia, increased alanine aminotransferase and gamma glutamyl transpeptidase, and hyperbilirubinemia in several animals. Choleliths ranged in size from sand-like particles to 5 mm in diameter. Gallstones from five animals were analyzed by accepted analytical methods. Results showed the gallstones to be composed primarily of cholesterol (89%). The gallbladder was histologically normal in all cases examined. The etiopathogenesis of cholelithiasis in the owl monkey is unknown.     

Erythrocyte glyoxalase I polymorphism in the owl monkey,Aotus

Three erythrocyte glyoxalase I phenotypes were observed in a sample of 235 karyotypically defined New World owl monkeys, Aotus. The selective distribution of glyoxalase I allele (GLO¹, GLO²) is related to the karyotype of each animal. Owl monkeys with a karyotype VI had an equal distribution of GLO¹ and GLO² genes in the population. Aotus with karyotype II, III, IV, or V had, exclusively, the GLO² allele (expressed as the fast electrophoretic phenotype), in contrast with monkeys with karyotype I or VII, which had only the GLO¹ allele (expressed as the slow electrophoretic phenotype).     

Sleep Profile and Longevity in Three Generations of a Family of Captive Bolivian Aotus

The daily total sleep time (TST) of the only nocturnal simian primate, Aotus spp., remains little studied under controlled conditions. We conducted 3 experiments in 4 owl monkeys (Aotus sp.), aged 1–27+ yr, to determine the daily TST. We housed 3 their—a nuclear family—in 1 cage and the remaining senescent female in an adjacent separate cage. We monitored their activity-sleep pattern longitudinally for 15–20 d via actigraphy: by tagging an acclerometer-type miniature transmitter (Actiwatch-MINIMITTER) sensitive to omnidirectional movement, to the owl monkey's neck. The TST (9.5–12.5 h) was ca. 4.5–7 h less than the 17 h Perachio reported for owl monkeys in 1971 by polysomnography, under similar 12-h-light; 12-h dark conditions. Our finding corroborates well with the TST for other nonhuman primates. Four members of the Aotus colony at our facility reached 20 yr in captivity; the oldest (wild-born female) is still living at >27 yr, and the second oldest (captive-born male), is 23 years now.     

Pattern of maternal circulating CRH in laboratory‐housed squirrel and owl monkeys

The anthropoid primate placenta appears to be unique in producing corticotropin‐releasing hormone (CRH). Placental CRH is involved in an endocrine circuit key to the production of estrogens during pregnancy. CRH induces cortisol production by the maternal and fetal adrenal glands, leading to further placental CRH production. CRH also stimulates the fetal adrenal glands to produce dehydroepiandrostendione sulfate (DHEAS), which the placenta converts into estrogens. There are at least two patterns of maternal circulating CRH across gestation among anthropoids. Monkeys examined to date (Papio and Callithrix) have an early‐to‐mid gestational peak of circulating CRH, followed by a steady decline to a plateau level, with a possible rise near parturition. In contrast, humans and great apes have an exponential rise in circulating CRH peaking at parturition. To further document and compare patterns of maternal circulating CRH in anthropoid primates, we collected monthly blood samples from 14 squirrel monkeys (Saimiri boliviensis) and ten owl monkeys (Aotus nancymaae) during pregnancy. CRH immunoreactivity was measured from extracted plasma by using solid‐phase radioimmunoassay. Both squirrel and owl monkeys displayed a mid‐gestational peak in circulating CRH: days 45–65 of the 152‐day gestation for squirrel monkeys (mean±SEM CRH=2,694±276 pg/ml) and days 60–80 of the 133‐day gestation for owl monkeys (9,871±974 pg/ml). In squirrel monkeys, circulating CRH declined to 36% of mean peak value by 2 weeks before parturition and then appeared to increase; the best model for circulating CRH over gestation in squirrel monkeys was a cubic function, similar to previous results for baboons and marmosets. In owl monkeys, circulating CRH appeared to reach plateau with no subsequent significant decline approaching parturition, although a cubic function was the best fit. This study provides additional evidence for a mid‐gestational peak of maternal circulating CRH in ancestral anthropoids that has been lost in the hominoid lineage. Am. J. Primatol. 72:1004–1012, 2010. © 2010 Wiley‐Liss, Inc.     

Fine Structural Analysis of the Silk Apparatus in the Funnel-web Spider, Agelena limbata (Araneae: Agelenidae)

ABSTRACT Silk apparatus of the funnel-web spider, Agelena limbata was located at the ventral end of the abdominal part, and was composed of internal silk glands and external spinnerets. Among the three pairs of spinnerets, the posterior pairs were highly elongated along the body axis. By the light and electron microscopic inspections, it was found that four types of silk glands were connected through the typical spinning tubes of each spinneret. Anterior spinnerets comprise 2 pairs of the ampullate and 125 to 150 pairs (female) or 110 to 114 (male) of pyriform glands. Another 2 pairs of ampullate glands in both sexes, 5 to 8 pairs of tubuliform glands in females, and 20 to 26 pairs (female) or 15 to 17 pairs (male) of aciniform glands were connected on the median spinnerets. Additional 8 to 10 pairs of tubuliforms in female and 41 to 53 pairs (female) or 27 to 32 pairs (male) of aciniform glands were on the posterior spinnerets, respectively. While the ampullate and tubuliform glands were connected with the spigot-type spinning tubes, the pyriform and aciniform glands with that of spool-type tubes. It has been also revealed that the tubuliform glands were only observed in female spiders, however the flagelliform and aggregate glands which had the function of adhesive thread production in orb-web spiders were not observed at both sexes of this spiders.     

A putative homoeolog of human chromosome 12 in the owl monkey

Analyses of Southern blots of rodent x owl monkey somatic cell hybrids permitted syntenic assignment of gene loci coding for triosephosphate isomerase (TPI), antigen CD4(T4), Kirsten rat sarcoma 2(KRAS2) virus, insulin-like growth factor 1 (IGF1), and alpha 2-macroglobulin (A2M) to chromosome 10 of owl monkey karyotype VI(2n = 49, 50). In addition, regional in situ localization of the T4 and KRAS2 loci on the proximal region of the long arm of this acrocentric chromosome and on the corresponding homologous region on the long arm of metacentric chromosome 1 of karyotype IV (2n = 52) substantiated our hypothesis that a single fusion or fission event is responsible for the polymorphism in chromosome number characteristic of owl monkeys from at least three allopatric populations. The study supports a putative homoeology between owl monkey chromosome 10 (K-VI) and human chromosome 12. The morphological differences between these two primate chromosomes indicate evolutionary rearrangements involving at least one pericentric inversion.     

Two new karyotypes in the Peruvian owl monkey (Aotus trivirgatus)

The observation of remarkable karyotypic variation in owl monkeys (Aotus trivirgatus) stimulated us to study the chromosomal evolution of this New World genus. As an extension of this project, we examined the chromosome complement of a “phenotype-B” Aotus population from Peru. In addition to karyotype V(2n = 46), two new karyotypes with diploid numbers of 47 and 48 were identified. A G-band comparison of these karyotypes indicated that the chromosome number polymorphism in these Peruvian owl monkeys resulted from a single fusion or fission event involving a single metacentric and two acrocentric chromosome pairs. This mechanism is also known to be responsible for the chromosome number polymorphism in at least two other populations of phenotype B Aotus, one from Colombia and the other from Panama.     

Leishmania braziliensis: development of primary and satellite lesions in the experimentally infected owl monkey, Aotus trivirgatus

Twelve male and 8 female feral owl monkeys, Aotus trivirgatus, were inoculated intradermally at the dorsal base of the tail with 2 X 10(7) promastigotes (strains WR 128 or WR 539) or 5 X 10(5) amastigotes (strain WR 128) of Leishmania braziliensis panamensis, and the progression and regression of subsequent lesions were examined for up to 13 or 54 weeks after inoculation. Three of these monkeys had been infected previously with L. donovani, had been treated with meglumine antimoniate, and had recovered clinically from visceral leishmaniasis. All monkeys developed a cutaneous nodule at the inoculation site, but the size of the nodule varied (maximum 78 to 326 mm2 between 4 and 16 weeks after inoculation.) The initial nodule became ulcerated after 4 to 8 weeks in 17 of the 20 monkeys, and the ulcers persisted for 4 to 16 weeks until covered by a crust. Primary lesions disappeared by 17 to 52 weeks after inoculation, but satellite lesions, of similar morphology to the primary lesions but smaller, developed after 4 to 21 weeks in 14 of the monkeys. The primary nodule was excised in 4 monkeys at 6 weeks and did not recur nor did satellite lesions subsequently develop. The satellite lesions (median total number of 4, range 1 to 25) were adjacent to or at a maximum distance of 6 cm from the primary lesion, varied in size from 3 to 117 mm2, and persisted for 10 to 37 weeks. At 6 and 8 weeks after inoculation, tissue from the cutaneous leishmanial lesions from five monkeys was excised and examined. The granulomatous leishmanial lesions, located primarily in the dermis and subcutis, consisted of macrophages containing parasites, lymphocytes, plasma cells, and occasionally eosinophils. Satellite lesions at 14 weeks after inoculation were similar grossly and microscopically to the initial nodule. No significant differences were observed between promastigote or amastigote derived infections, between the two strains of L. b. panamensis, or between the course of infection based on the sex, age, karyotype, or country of origin of the owl monkeys. Cutaneous lesions developed when 5 X 10(5) amastigotes of L. b. panamensis (strain WR 128) were inoculated intradermally into the dorsal base of the tail, the upper eyelid, and the thorax of three monkeys. Leishmanial nodules which developed on the thorax regressed rapidly (after 2 to 5 weeks) whereas those on the upper eyelid and at the dorsal base of the tail persisted for 5 to 45 weeks after inoculation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Mated pairs of owl monkeys (Aotus nancymaae) exhibit sex differences in response to unfamiliar male and female conspecifics

In socially monogamous species, mate‐guarding could be a reproductive strategy that benefits both males and females, especially when males contribute to parental care. By actively guarding mates, males may reduce their chances of being cuckolded, whereas females that mate‐guard may reduce the likelihood that their mates will desert them or acquire additional mates, and hence limit or reduce paternal care of offspring. Owl monkeys (Aotus spp.) are socially monogamous with biparental care of young and, hence, potential beneficiaries of mate‐guarding. We presented mated pairs of captive owl monkeys (A. nancymaae) with unfamiliar male and female conspecifics, to determine if either member of the pair exhibits intraspecific aggression toward an intruder or stays close to its mate, behaviors indicative of mate‐guarding. Male mates were more responsible for the maintenance of close proximity between mates than females. Male mates also exhibited elevated levels of behavior that signify arousal when presented with a male conspecific. These responses by mated male owl monkeys are consistent with patterns that may help prevent cuckoldry. Am. J. Primatol. 72:942–950, 2010. © 2010 Wiley‐Liss, Inc.     

Thyroid activity in a hypometabolic primate, the owl monkey (Aotus trivirgatus).

Serum levels of triiodothyronine (T3) and tetraiodothyronine (T4) were significantly lower in owl monkeys than in long-tailed macaques. These observations were considered to be consistent with the lower metabolic rate of the owl monkey. However, the absence of a significant difference in the levels of thyroid stimulating hormone (TSH) between the two species suggested a lower thyroid sensitivity to TSH in the owl monkeys. There was an inverse relation between levels of T3 and TSH in the owl monkeys at night and during the day.     

Advantages of the WRAIR whole blood cholinesterase assay: comparative analysis to the micro-Ellman, Test-mate ChE, and Michel (DeltapH) assays

Red blood cell AChE (RBC-AChE) and plasma BChE can be used as sensitive biomarkers to detect exposure to OP nerve agents, pesticides, and cholinergic drugs. In a comparative study, RBC-AChE and serum BChE activities in whole blood was obtained from forty seven healthy male and female human volunteers, and then exposed separately ex vivo to three OP nerve agents (soman (GD), sarin (GB) and VX) to generate a wide range of inhibition of AChE and BChE activity (up to 90% of control). These samples were measured using four different ChE assays: (i) colorimetric microEllman (using DTNB at 412 nm), (ii) Test-mate ChE field kit (also based on the Ellman assay), (iii) Michel (delta pH), and (iv) the Walter Reed Army Institute of Research Whole Blood (WRAIR WB) cholinesterase assay. The WRAIR assay is a modified Ellman method using DTP at 324 nm (which minimizes hemoglobin interference and improves sensitivity), and determines AChE and BChE in a small whole blood sample simultaneously. Scatter plots of RBC-AChE activities were determined using the WRAIR ChE assay versus the micro-Ellman, Test-mateTM and Michel after exposure to varying concentrations of soman, sarin and VX. Regression analyses yielded mostly linear relationships with high correlations (r2 = 0.83-0.93) for RBC-AChE values in the WRAIR assay compared to the alternate methods. For the plasma BChE measurements, individual human values were significantly more variable (as expected), resulting in lower correlations using WRAIR ChE versus the alternate assays (r2 values 0.5 - 0.6). To circumvent the limitations of simple correlation analysis, Bland and Altman analysis for comparing two independent measurement techniques was performed. For example, a Bland and Altman plot of the ratio of the WRAIR whole blood AChE and Michel AChE (plotted on the y-axis) vs. the average of the two methods (x-axis) shows that the majority of the individual AChE values are within +/- 1.96 S.D. of the mean difference, indicating that the two methods may be used interchangeably with a high degree of confidence. The WRAIR ChE assay can be thus be used as a reliable inter-conversion assay when comparing results from laboratory-based (Michel) and field-based (Test-mateTM ChE kit), which use different methodology and report in different units of AChE activity.     

Hormonal monitoring of reproductive status in monogamous wild female owl monkeys (Aotus azarai) of the Argentinean Chaco

The Neotropical owl monkeys (Aotus spp.) are a good model for evaluating the hypothesis that monogamy may arise if female reproductive cycles limit the mating potential of males. To evaluate this hypothesis, we first needed to assess the feasibility of using fecal sampling for monitoring the reproductive status of females. We collected fecal samples (n = 242, from 7 females) from wild adult Aotus azarai females in the Gran Chaco forests of Argentina during 3 years. Fecal estrone-1-glucuronide (E(1)C) and pregnenadiol-3-glucuronide (PdG) tended to rise in parallel during the luteal phase. The average cycle length was 22 ± 3 days (n = 5 females, 10 cycles). We identified 2 conceptive cycles and characterized the E(1)C and PdG profiles of 2 pregnancies. This report is the first of its kind on wild female owl monkeys. Despite the difficulties in sample collection and processing in the field and providing a species-specific validation in the laboratory, we show that fecal samples from A. azarai can be used for monitoring female reproductive status and function.     

Rensch's rule, Bergmann's effect and adult sexual dimorphism in wild monogamous owl monkeys (Aotus azarai) of Argentina

Some monogamous primates are characterized by biparental care, territoriality, and a reduced level of physical dimorphism. In others, the relationship between those behavioral patterns and dimorphism is less clear. I tested Bergmann's and Rensch's rules using Aotus spp. body mass data and I characterized the extent of sexual dimorphism in body mass, dental and physical measurements in a socially monogamous owl monkey population (n = 91 adults) from the Argentinean Gran Chaco. A. azarai azarai from the Argentinean Chaco is larger than the more tropical owl monkey species (r = 0.7, N = 6 species), but there is no apparent increase in sexual dimorphism with increased body mass. The body masses of adult male and female A. a. azarai were remarkably similar (Mean = 1.26 kg); there were no marked sex differences in most skeletal measurements, but males had higher and wider upper and lower canines than did females. Body mass and neck circumference were positively and strongly related (r = 0.533, n = 52), and the body mass of adults was not a reliable indicator of their age (r = 0.03, n = 10). The data illustrate the complexities inherent in examining and summarizing within population variation in skeletal and nonskeletal measurements and contribute to a better understanding of the relationships between monogamous behavioral patterns and sexual dimorphism.     

Infant Development and Parental Care in Free-Ranging <Emphasis Type="Italic">Aotus azarai azarai</Emphasis> in Argentina

Studies of infant development and parental behavior in free-ranging owl monkeys have been constrained by their nocturnal habits. Taking advantage of the cathemeral activity pattern of Aotus azarai azarai in the Argentinean Chaco, we describe the development of a cohort of free-ranging infants born in an owl monkey population in Formosa Province. We observed 7 infants, whose birth dates are known to the nearest week, to record details of their development and care between October 1999 and March 2000. We collected 92 h of behavioral data in 76 sessions. The infants were almost never off the parents during the first 4 wk of life, and we observed no infant being transported by a nonadult. The parent carrying the infant traveled most frequently in the middle of the group, sometimes first, but rarely last. The mean duration of 33 nursing episodes is 69 sec. After nursing, the infant was more likely to return to the nonnursing adult than to remain with the mother suggesting that in owl monkeys the infant may be primarily attached to the adult male in the group. Infants began to explore, to manipulate and to consume solid foods during the second month. Our observations are comparable to ones on captive breeding groups of Colombian owl monkeys (Aotus lemurinus) and Bolivian owl monkeys (A. azarai boliviensis) under controlled conditions of temperature, illumination and food availability.