Two new species of night monkeys,genus Aotus (Cebidae,platyrrhini): A preliminary report on Aotus taxonomy

The nine allopatric species of Aotus recognized represent two natural groups distinguished by karyotype, color, and pelage patterns. Correlated with these group characters are reported differences in serum proteins and degrees of susceptibility or immunity to experimental infection with malarial parasites. The primitive gray-neck species group of Aotus contains A. brumbacki (new species), A. lemurinus (with subspecies lemurinus and griseimembra), A. trivirgatus, and A. vociferans. The derived red-neck group contains A. nancymai (new species), A. miconax. A. infulatus, and A. azarae (with subspecies azarae and boliviensis). Only the two new species are described but a key to the species and subspecies gives the diagnostic characters of each. The gray-neck group occurs almost entirely north of the Amazon, the red-neck group almost entirely south. The distributional exceptions are enclave populations resulting from river bend cutoffs. Formation of an enclave population of A. nancymai is discussed and available information on the biology of this species is reported.     

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.     

Urinary enzyme concentrations in the owl monkey (Aotus nancymae)

The activity of three urinary enzymes, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and N-acetyl-β-D-glucosaminidase (NAG), was evaluated in 71 adult owl monkeys. Fifty-six animals had normal renal function, while 15 had evidence of renal dysfunction. Urinary enzyme: urinary creatinine ratios (U_E:U_Cr) were also determined. The activity for NAG was similar to that of other species, while ALP and AST were higher. Regression analyses revealed that urinary enzymes and U_E:U_Cr were significantly correlated (P ≤ 0.0001) with indices of renal damage and could identify active renal disease.     

Cytogenetic studies of Aotus from Eastern Amazonia. Y/Autosome rearrangement

Twenty-one specimens of Aotus were captured on both sides of the Tocantins river when the hydroelectric reservoir of Tucuruí, Brazil, was filled. The males had a diploid number of 49 chromosomes, and the females had 50. The observed difference is a consequence of the fusion of the Y chromosome with an autosome. The karyotype is similar to that of the Bolivian Aotus (A. azarae boliviensis). It differs, however, in the G- and C-banding patterns of the chromosome resulting from the Y/autosome fusion. The nucleolar organizing region is located on the secondary constriction of a pair of submetacentric chromosomes. Considerations are presented on the classification of A. infulatus as a separate species.     

Erythrocytes and erythrocyte morphologies of healthy and colony-born owl monkeys (Aotus lemurinus griseimembra)

Inadequate availability of hematological reference data seriously restricts optimal utilization of the owl monkey (Aotus lemurinus griseimembra) as an experimental model. The current study investigated erythrocytic morphology in peripheral blood of healthy, colony-born owl monkeys. The blood of the subjects contained discoid erythrocytes, poikilocytes, and showed considerable anisocytosis. Also observed were nucleated erythrocytes, erythrocytes with Howell-Jolly bodies, and reticulocyte types I, II, and III. Heinz bodies were not detected.     

Chromosome evolution in the owl monkey,Aotus

We have reported nine distinct karyotypes for Aotus, of four pelagic phenotypes, and suggest that this single species has undergone extensive subspeciation. We reconstruct the mechanism of chromosomal evolution and propose a hypothesis about the events of subspeciation in Aotus. We speculate that isolated groups of ancestral individuals living in several confined areas have separately accumulated a fusion or inversion pair as a result of inbreeding. A subsequent reassociation of descendants from these individuals led to the formation of offspring with mixtures of fusion or inversion pairs in their complements. They, in turn, radiated into different ecological niches accompanied by adaptive genetic changes and eventually gave rise to the present forms of Aotus distinguishable by their karyotypes, but not easily recognizable by ordinary taxonomic criteria.     

Serum and urine biochemical diversity among wild-caught and colony-born Aotus nancymae

Serum and urine analytes were compared between adult wild-caught and adult colony-born owl monkeys (Aotus nancymae), to determine if normative clinical pathology data were similar. Significant differences (P ≤ 0.05) were noted in serum protein, glucose, sodium, urine calcium, calcium clearance, and fractional clearance of calcium between the two groups. The results suggest that reference data for feral owl monkeys is not completely applicable to colony-born animals, however, the differences are too small to be of clinical significance.     

Reference values for peripheral blood lymphocytes from Aotus lemurinus ssp. griseimembra (owl monkey)

The reactivities of several monoclonal antibodies that define human lymphocyte cell-surface antigens have been tested with peripheral blood lymphocytes of Aotus lemurinus ssp. griseimembra. Based on reactivity patterns in humans, reactive MoAb were identified that mark pan-T, helper/inducer, suppressor/cytotoxic, pan-B, and natural killer cells. Reference values of these subsets in Aotus are presented. These MoAb should provide a useful tool for further phenotypic and functional dissection of the immune system in this simian model of human disease.     

Karyotypic evolution in Aotus

Great karyotypic diversity exists within the platyrrhine genus Aotus. Primarily by comparing banded karyograms of different forms of Aotus, the pattern of karyotypic evolution can be assessed. Out-group comparisons are used to establish primitive and derived states of particular chromosomes, and a parsimonious cladogram is constructed. Other karyotypic changes are then positioned at appropriate nodes of the cladogram. The resulting phylogenetic hypothesis is entirely self-consistent, is in accord with out-group comparisons, does not invoke hybridization between ancestral forms, and, importantly, indicates a single origin for each rearrangement of euchromatic segments. Moreover, it is consistent with the hypothesis, derived from pelage studies, that the more southerly Aotus taxa constitute a holophyletic group. The reconstructed ancestral karyotype had a diploid number of 54. There has been little loss of euchromatic material during Aotus evolution.     

Disappearances of individuals from social groups have implications for understanding natal dispersal in monogamous owl monkeys (Aotus azarai)

The socially monogamous owl monkeys (Aotus spp.) live in small groups of two to five individuals. We used monthly demographic data collected from 16 social groups between 1997-2001 to estimate the age of disappearance from their natal groups and the timing of those disappearances in a population of owl monkeys (Aotus azarai azarai) in Formosa, Argentina. We applied survival analysis techniques to 48 months of observations of 47 individuals to construct age-specific probabilities of disappearance. Two-thirds of the individuals (eight of 12), for which disappearance could be well timed, disappeared at around 2 years of age. The average age at disappearance for these individuals was 29 months (+/-8), whereas the mean age of disappearance obtained from the survival analysis of censored and uncensored data was almost 3 years (mean+/-SD, 35+/-3 months). Ninety-two percent of all disappearances of adult size individuals (11 of 12) occurred around the birth season. Our data suggest that at least some individuals disperse soon after sexual maturation while others remain for up to 4 years in their natal groups.     

Chromosomal diversity in the genus Arvicanthis (Rodentia, Muridae) from East Africa: a taxonomic and phylogenetic evaluation

In this paper we discuss the contribution of cytogenetics to the systematics of Arvicanthis in East Africa, by reviewing all the known chromosomal cytotypes of the genus in the area. We also provide G‐ and C‐banding comparisons for two recently described karyotypes, provisionally named ANI‐5 (2n = 56, NFa = 62) and ANI‐6 (2n = 60, NFa = 72). This, therefore, brings the total number of known cytotypes in this area to 10. Five of these correspond to the species recognized by the latest rodent checklist, i.e. A. nairobae (2n = 62, NFa = 78), A. neumanni (2n = 52–53, NFa = 62), A. blicki (2n = 48, NFa = 62), A. abyssinicus (2n = 62, NFa = 64) and A. niloticus (2n = 62, NFa = 60–62). The taxonomic status of the remaining five cytotypes (A. cf. somalicus, 2n = 62 NFa = 62–63; ANI‐5, 2n = 56, NFa = 62; ANI‐6/6a 2n = 60, NFa = 72/76; ANI‐7, 2n = 56, NFa = 78; and ANI‐8, 2n = 44, NF = 72) is discussed. Finally, we reconstruct the phylogenetic relationships among all the known karyotypes on the basis of banding data available for the genus in Africa and show the occurrence of two main clades, each characterized by different types of chromosomal rearrangements. The times of the cladogenetic events, inferred by a molecular clock, indicate that karyotype evolution has accomplished almost all the dichotomic events from the end of the Miocene to the present day. The discovery of a large chromosomal differentiation between populations showing low genetic distances and intrapopulation chromosomal polymorphism suggests that the process of chromosomal differentiation in Arvicanthis is still ongoing and may possibly be responsible for speciation.     

Tuberculosis-like lesions arising from the use of Freund's complete adjuvant in an owl monkey (Aotus sp.)

An apparently normal, non-tuberculin-reacting, splenectomized owl monkey presented tuberculosis-like lesions of the lung at necropsy. Histological and bacteriological examination failed to demonstrate the presence of acid-fast organisms. Retrospective inquiry showed the animal had been inoculated using complete Freund's adjuvant during a malaria vaccine trial. Lesions observed were compatible with lipid embolism of the adjuvant in the lungs.     

Spontaneous cardiomyopathy and nephropathy in the owl monkey (Aotus sp.) in captivity.

Clinical and pathologic data were reviewed for 72 owl monkeys that died between January 1987 and May 1990 at the Center for Reproduction and Conservation of Nonhuman Primates in Iquitos, Peru. Tissue samples from 39 animals were examined. Hypertrophic cardiac disease (51% of animals examined), dilative cardiomyopathy (26%), and nephropathy (87%) were the most common diagnoses. The incidence of all three diseases appeared to increase with time in captivity. Nephropathy was less severe in colony-born animals.     

Restasis® for the treatment of 'dry eye' in Aotus nancymaae

Background  This case report describes the treatment of three male owl monkeys ( Aotus nancymaae ) diagnosed with chronic dry eye with a topical cyclosporine product, Restasis^®, approved for use in humans. These owl monkeys had ocular disease resulting from procedures performed at a biotechnology company. They were moved to the Center for Neotropical Primate Research and Resources at University of South Alabama to be incorporated into the breeding colony.
Materials and methods  Schirmer tear testing was performed initially and during the course of treatment to monitor efficacy of twice daily administered Restasis^®. The goals of treatment were to reduce pain and/or distress and if possible to quantitatively increase tear production.
Results and discussion  All animals had improvements in conjunctival inflammation and had an increase in tear production.     

Karyological studies on the Sino-Himalayan genus, Cremanthodiurn (Asteraceae: Senecioneae)

Twenty-two populations of seven species of Cremanthodium from high altitude regions of western China were observed karyologically. C. ellisii, C. microglossum, C. brunneo-pilosum, C. stenoglossum, C. discoideum and C. lineare all had the same chromosome number of 2 n = 58 whereas C. humile had 2 n = 60. All chromosome numbers of these species are documented here for the first time. The basic number of x = 30 is new for this genus. The karyotypes of all species belong to 2A type according to Stebbins' asymmetry classification of karyotypes. Two basic chromosome numbers, x = 30 and x = 29 in Cremanthodium , correspond exactly to two branching patterns in this genus, sympodial versus monopodial. The systematic and taxonomic statuses of the sympodial species need further study. The karyomorphological data provide no support to the sectional subdivision in Cremanthodium .     

Surgical bone marrow aspiration in Aotus lemurinus griseimembra

Aotus lemurinus griseimembra are highly susceptible to infection by human malaria parasites and reproduce some of its clinical manifestations, including anemia. We developed a new surgical technique to obtain bone marrow samples from Aotus by surgical aspiration of the femur. First, we determined that the femur offered advantages over other bones, primarily due to lower fracture vulnerability. We tested a surgical technique using 20 G IV catheters in formaldehyde-preserved animals, then conducted the procedure on 27 live animals. This technique provided easy, quick surgical access to adequate volumes of bone marrow and was safe for almost all animals: only one died; another developed nervous impairment of the lower limb. Adequate cell samples were obtained in all animals and allowed cytological studies. This procedure offers a useful tool for bone marrow research in Aotus and helps overcome current limitations of such research in human where these studies are limited by ethical and technical issues.     

Chromosome number and karyotype of Phaenospermateae and Duthieeae (Poaceae), with reference to their systematic implications

Recent molecular phylogenetic studies indicate that Phaenospermateae and Duthieeae are among the early diverging lineages of Pooideae and that they are closely related to each other. Here, we test this with cytotaxonomical data. The monotypic tribe Phaenospermateae, represented by Phaenosperma globosum, has a chromosome number of 2n = 2x = 24 and a fairly symmetric karyotype consisting of 22 median (m) and 2 submedian (sm) chromosomes varying in length between 1.8–3 μm. Duthieeae, represented by Duthiea brachypodium, Sinochasea trigyna, Stephanachne monandra and Stephanachne pappophorea, also share the chromosome number 2n = 2x = 24 and similar symmetric karyotypes with the chromosomes varying in length between 1.4–5 μm. Thus, the close relationship of Phaenospermateae and Duthieeae is corroborated.     

Puberty in the male owl monkey (Aotus trivirgatus griseimembra): A study of physical and hormonal development

In the male owl monkey (Aotus trivirgatus),the onset of puberty occurs at between 211 and 337 days (median, 313) as indicated by longitudinal measurements of plasma testosterone in six subjects. Larger rises in plasma testosterone were observed between 300 and 400 days. Pubertal increases in body weight and testicular volume are not pronounced in this species. Young animals first entered the weight range for adult males (800–1080 g) when they were between 370 and 520 days of age (median, 472). Marked growth of the subcaudal scentmarking gland occurred during puberty. The first signs of development of this gland (stiffening and discoloration of overlying hairs) were noted between 282 and 370 days (median 316), and it had attained an adult structure by 336–442 days (median, 397). These changes were androgen dependent as indicated by the fact that treatment of a prepubertal male with testosterone stimulated the subcaudal gland to develop prematurely. Hormonal and physical changes during puberty were the same whether males remained with their parents or were caged alone. There was no indication that puberty was retarded in males which had remained in their natal groups.