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PubMedDate not supplied

Energy intake during reproduction in captive common marmosets (Callithrix jacchus).

Among haplorhine primates, the highly specialized Callitrichidae (marmosets and tamarins) are expected to have comparatively high reproductive costs, a feature that might be related to the evolution of a cooperative breeding system. Costs of reproduction in captivity were investigated on the basis of changes in energy intake and body weight during pregnancy and lactation in pair-living female and male common marmosets (Callithrix jacchus). The experimental design had little effect on carrying behavior, food intake, and body weight of adults, but a negative transitory effect of offspring body weight. Increased energetic requirements during pregnancy did not result in a higher energy intake in females. During lactation, females increased their energy intake up to 100% and gradually lost weight, suggesting even higher costs. Extensive carrying behavior by males, on the other hand, did not result in an increased energy intake in males, or in changes in male body weight. It is suggested that, at least in captivity, increased energetic demands during reproduction are reduced by behavior allocations towards energetically less expensive behaviors.

Aging↗

PubMed2000

The lung of the marmoset (Callithrix jacchus): ultrastructure and morphometric data.

Owing to its small size (body weight 300-400 g), its modest demands on animal husbandry, and in particular its relatively long life-span (up to 12 years) the common marmoset (cotton ear marmoset: Callithrix jacchus (Cj)) might be a useful animal model to study the adaptive capacity to different energetic demands, adverse environmental influences such as air pollution, and aging of the lung. In order to describe the gas exchange apparatus of healthy marmosets as a basis for further pulmonary research, the lungs of three young adult animals have been analysed both qualitatively and quantitatively (by morphometry) at the light and electronmicroscopic level. Qualitatively, there is a general similarity in the architecture and structure of lung parenchyma between marmosets and other mammals. Quantitatively, the alveolar surface area was found to be 7662+/-1647 cm(2). Capillary surface area and volume were 6000+/-1549 cm(2), and 1.01+/-0.34 ml, respectively. The harmonic mean thickness of the air-blood barrier was 0.517+/-0.117 microm. These morphometric parameters allowed to estimate the diffusing capacity for oxygen at 0.0299+/-0.0134 ml O(2) (sec mmHg)(-1). In comparison with mammals of similar body size (rats, quinea pigs) it appears that the marmoset has a higher gas exchanging capacity of the lung, which might reflect the 'athletic' activity of this small primate. An incidental finding worth mentioning is the individual variability of septal structures due to variations in capillary blood volume and hematocrit. The distinction between such functional variations and subtle pathologic alterations of lung tissue requires a morphometric analysis at the electron-microscopic level.

Animals↗

PubMed1995

Assessment of tissue integrity, ultrastructure and steroidogenic activity of corpora lutea of the marmoset monkey, Callithrix jacchus, following in vitro microdialysis.

Microdialysis of marmoset (Callithrix jacchus) corpora lutea in vitro was evaluated regarding morphology, activity of 3 beta-hydroxysteroid-dehydrogenase (3 beta-HSD) and progesterone (P) secretion. Two different dialysis media were used: an unbuffered ringer solution and Krebs-Henseleit buffer gassed with carbogenium. Additionally, the effects of the luteotrophin prostaglandin E2 (PGE2) on P secretion were examined for both media. In general 3 zones of tissue according to the maintenance of cellular integrity could be identified after dialysis. Structurally intact cells were found in close vicinity to the dialysis tubing or the bathing medium after 8 h of perfusion. These 2 zones were separated by a sheet of cells which showed signs of ischemic injury and whose activity of 3-beta-HSD was reduced. During dialysis with ringer solution P release stayed constantly high for a longer period of time than with Krebs buffer. With both media PGE2 stimulated P release but could not prevent the decrease in P production during dialysis with Krebs buffer. In general profiles of baseline secretion, were more stable after treatment than for untreated corpora lutea. There, under dialysis with ringer solution, the ultrastructure of cells close to the dialysis tubing was well preserved exhibiting euchromatic nuclei, tubular sER and numerous mitochondria gathered in the perinuclear region. In contrast, with Krebs buffer heterochromatization of nuclei and vesiculation of smooth endoplasmic reticulum prevailed. After application of PGE2 no histological and ultrastructural differences could be found between tissue dialysed with ringer or Krebs buffer. In these specimens the sER of zone A cells generally appeared vesiculated. Our results indicate (1) a close structure-function relationship of luteal cells in the tested system, (2) the suitability of the system to study intra-luteal regulation and (3) the necessity to control structural integrity of the dialysed tissue.

3-Hydroxysteroid Dehydrogenases↗

PubMed1996

Expression of integrins in marmoset (Callithrix jacchus) ovary during folliculogenesis.

Integrins were localized immunohistochemically in marmoset ovaries (Callithrix jacchus) of defined cycle stages. With monoclonal antibodies against beta 1, alpha 2, alpha 3, and alpha 6 integrin subunits, immunoreactivity was predominantly found in ovaries of the follicular phase. In the luteal phase, non-luteal cells, e.g. fibroblasts or endothelial cells expressed beta 1, alpha 2, or alpha 6 integrins. Immunostaining for the beta 1 subunit was strongest in granulosa cells of all growing follicles. Weak immunoreactivity was found in granulosa cells of atretic follicles, theca and interstitial cells. With the alpha 2 antibody, binding was evident in granulosa cells of many, but not of all, primordial and primary follicles. Expression of alpha 2 was also found in luteinized granulosa cells of tertiary follicles. In growing follicles, immunoreactivity of alpha 3 was restricted to granulosa cells of early secondary follicles. Within the epithelium, staining was almost exclusively found in granulosa cells bordering on the basal granulosa cell layer. In advanced stages of atresia, granulosa cells of antral follicles expressed the alpha 3 subunit. Integrin alpha 6 expression was evident in granulosa cells of all growing follicles but was absent during advanced stages of degeneration. The specific expression patterns of integrins suggest that these matrix receptors play a regulatory role during cyclic events in primate ovaries.

Animals↗

PubMed1997

Receptive field dimensions of lateral geniculate cells in the common marmoset (Callithrix jacchus).

We measured the spatial receptive field dimensions of cells in the lateral geniculate nucleus (LGN) of the common marmoset (Callithrix jacchus) using a bipartite field stimulus in which the two halves of the field were modulated identically but in counterphase. Horizontal and vertical edges between the two fields were positioned at different locations in the receptive field. By assuming that centers and surrounds have gaussian profiles, we were able to obtain a satisfactory mathematical description of the data. Receptive field centers were about a factor 1.6 larger than those of macaque LGN cells, in accordance with the smaller marmoset eye. There was a limited correspondence with dendritic tree dimensions of marmoset retinal ganglion cells. We further found that center and surround gaussians were not always concentric, and that the centers of some cells were elongated. This might allow some direction or orientation biases in LGN cells.

Algorithms↗

PubMed1998

Expression of accessory molecules and cytokines in acute EAE in marmoset monkeys (Callithrix jacchus).

Accessory molecules and cytokines are involved in the immunopathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) in rodent models, and are potential targets for immunotherapy. Evaluation of such experimental therapies requires appropriate animal models. Therefore, we analysed the expression of selected accessory molecules and cytokines in the brain of marmoset monkeys (Callithrix jacchus) with acute EAE, a newly described non-human primate model for MS. All animals experienced active disease clinically and histopathologically with strong resemblance to MS. Perivascular infiltrates of mononuclear cells showed abundant expression of CD40. CD40 was expressed on macrophages, indicating that T cell priming and macrophage effector functions may result from local CD40-CD40L interactions. CD40 ligand (CD40L) and B7-2 (CD86) were also expressed, but to a lower extent, while B7-1 (CD80) expression was limited. Both pro-inflammatory and anti-inflammatory cytokines were produced within individual lesions during active disease (IFN-alpha, IFN-gamma, TNF-alpha, IL-1alpha, IL-1beta, IL-2, IL-4, IL-10 and IL-12). This suggests that relative levels rather than sequential expression of Th1- and Th2-type cytokines determine disease activity. These findings demonstrate the value of EAE in marmoset monkeys as a model to assess the role of accessory molecules and cytokines in multiple sclerosis, and to evaluate targeted intervention.

Acid Phosphatase↗

PubMed2000

Measuring fear and anxiety in the marmoset (Callithrix penicillata) with a novel predator confrontation model: effects of diazepam.

This report describes a new experimental method for measuring fear and anxiety in Cerrado marmosets (Callithrix penicillata). In order to test the sensitivity of the behavioral parameters to an anxiolytic substance, the effects of the benzodiazepine diazepam on the anxiety measures were examined. The strategy was to use a naturally occurring stimulus known to elicit anxiety and fear in this species. A taxidermized predator (the wild cat Felis tigrina) was chosen as the stimulus to induce anxiety-related behaviors on the basis of a preceding study in which various stimuli were systematically compared in their effectiviness to induce fear responses. The apparatus consisted of three parallel arms of equal dimensions, joining two perpendicular arms at each end, thus comprising a figure eight-like or five-arm continuous rectangular maze. The wild-cat was placed outside of one corner of the maze's outer parallel arms. Each subject was submitted to six treatments given in random order: three drug sessions (diazepam 1, 2 and 3 mg/kg, i.m.), saline, sham (injection control), and a control session, involving neither manipulation nor injection. Subjects were placed into the back of the chamber, out of sight of the 'predator', 20 min after a treatment and given free access to the maze for 30 min. The behavioral repertoire was recorded via videocamera. The following behaviors were considered to be possible indices of emotionality relevant to exposure to the predator in the paradigm used: scratching, scent marking, exploration, frequency and time spent in each of 13 defined sections of the maze. Administration of diazepam induced a significant reduction in scratching and an increase in the time spent in the vicinity of the 'predator', as well as in the frequency of exploratory behaviors, indicative of an anxiolytic effect. Gender did not influence the effect of treatment. These results suggest that this new ethologically-based test may be a useful method for studying anxiety and fear-induced avoidance in non-human primates and for pre-clinical research on psychoactive drugs.

Animals↗

PubMed1997

Brain-stem auditory evoked potentials in the common marmoset (Callithrix jacchus).

Brain-stem auditory evoked potentials (BAEPs) were recorded in 10 common marmosets (Callithrix jacchus) to investigate the effects of recording electrode configurations, stimulus rate, and stimulus frequency on BAEP wave forms and peak latencies. Tone burst stimulations were used to evaluate the effects of pure tone on BAEP wave forms. Five positive peaks superimposed on positive and negative slow potentials were identified in the BAEP recorded at the linkage between the vertex and the dorsal base of the ear ipsilateral to a monaural stimulus. When the reference electrode was placed at the ipsilateral mastoid or the neck, the amplitudes of positive and negative slow potentials and the incidence of wave I increased. There were no significant changes in peak latencies of BAEP waves with changes in stimulus rate from 5 to 20/s. It was possible to record the BAEPs in response to tone burst stimulations at frequencies extending from 0.5 to 99 kHz. Wave I appeared apparently at high stimulus frequencies; while waves III to V, at low frequencies. Wave II was recorded at frequencies ranging from 0.5 to 99 kHz and comprised a superposition of 2 or 3 potentials.

Acoustic Stimulation↗

PubMed2002

Anxiolytic-like effects of substance P fragment (SP(1-7)) in non-human primates (Callithrix penicillata).

The behavioral effects of the amino (N)-terminal fragment of substance P (SP(1-7)) on the marmoset (Callithrix penicillata) predator confrontation test of fear/anxiety were investigated. The test apparatus consisted of a figure-eight maze with three parallel arms interconnected at each extremity to a perpendicular arm. A taxidermized oncilla cat (Felis tigrina) was placed outside the maze facing one of its corners. Subjects were submitted to seven 30 min maze habituation trials (HTs), in the absence of the 'predator', and then to six 30 min treatment trials (TTs), in the presence of the 'predator', consisting of four doses of SP(1-7) (5, 50, 250 and 500 microg/kg; IP), saline and sham injection. SP(1-7) treatment reversed, in a dose-dependent way, the fear-induced avoidance behavior due to the predator's presence and increased the frequency of exploratory behaviors. Locomotor activity decreased during successive HTs, yet increased after all SP(1-7) treatments. These results indicate that systemic administration of SP(1-7) produces anxiolytic-like effects in marmosets tested in the predator confrontation model of fear/anxiety.

Animals↗

PubMed2000

Sequence and functional characterisation of the marmoset monkey (Callithrix jacchus) prolactin receptor: comparative homology with the human long-form prolactin receptor.

This study demonstrates the cloning and in-vitro characterisation of the marmoset monkey (Callithrix jacchus) prolactin receptor cDNA. The marmoset prolactin receptor cDNA was generated by reverse transcription-polymerase chain reaction using adrenal RNA and primers designed from prolactin receptor conserved regions. Sequence analysis predicts a mature protein of 598 amino acids exclusive of the 24 amino acid signal peptide. The marmoset prolactin receptor cDNA shares 93 and 61% base pair, and 89 and 61% amino acid sequence homologies with the long form human and rat prolactin receptor cDNA, respectively. The marmoset prolactin receptor cDNA sequence retains all the receptor sequences that have been shown previously to be essential for ligand binding, structural integrity and signal transduction. Transfection of human 293 fibroblast cells with the marmoset prolactin receptor cDNA (three independent experiments) confirmed the expression of a receptor that has high binding affinity to human growth hormone (K(a)=3.6+/-0.07 nM(-1) and B(max)=7.55+/-2.06x10(-11) M) and human prolactin (K(a)=3.1+/-0.12 nM(-1) and B(max)=2.87+/-0.66x10(-11) M). Functionality of the receptor was assessed by co-transfection of 293 fibroblast cells with marmoset prolactin receptor cDNA and the Jak2 cDNA, or marmoset prolactin receptor and a Stat5 responsive element linked to the luciferase coding sequence. Incubation of the cells with 18 nM ovine prolactin resulted in rapid phosphorylation of Jak2 as ascertained by Western blotting. In addition, the marmoset prolactin receptor cDNA led to 9.06+/-0.47-fold induction of luciferase gene activity. This was comparable with the induction observed following transfection with the human prolactin receptor cDNA (8.55+/-0. 5-fold). In-vivo prolactin receptor expression in the marmoset monkey was assessed by ribonuclease protection assay and detected in a number of tissues including female reproductive organs. These data confirm the cloning and functionality of the marmoset prolactin receptor cDNA. The marmoset prolactin receptor shares a high sequence homology with the long-form human prolactin receptor, and both receptors bind hormones with comparable affinity and confer a similar intracellular response. The marmoset monkey may provide a useful tool to investigate the role of prolactin in primate reproduction.

Amino Acid Sequence↗

PubMed2003

Selective age-related loss of calbindin-D28k from basal forebrain cholinergic neurons in the common marmoset (Callithrix jacchus).

A significant number of the cholinergic neurons in the basal forebrain of the primate, but not the rodent brain contain the calcium binding protein calbindin-D28k (CB). Previous experiments in our laboratory have demonstrated a substantial age-related loss of CB from the human basal forebrain cholinergic neurons (BFCN). The present study investigated the possible age-related loss of CB from the BFCN in a non-human primate species, the common marmoset (Callithrix jacchus). Quantitative analysis of matching sections as well as unbiased stereological determination of neuronal number were used in 16 adult marmosets ranging in age between 2 and 15 years. No significant changes were observed in the number of choline acetyltransferase-positive BFCN when a group of young animals (< or =4 years) was compared with a 6-8-year-old group and a 9-15-year-old group. Similarly, no age-related changes were observed in Nissl-stained magnocellular basal forebrain (putatively cholinergic) neurons. In contrast, the BFCN of the two older groups of animals displayed a significant loss of CB. The age-related loss of CB occurred in all sectors of the BFCN, but was greatest in the anterior sector of this cell group. The CB loss was neurochemically specific since the BFCN in the older groups of animals continued to express other markers such as high and low affinity neurotrophin receptors. The age-related loss of CB from the marmoset BFCN was also regionally selective as CB positive neurons in other structures, such as the cerebral cortex and the striatum displayed no apparent age-related changes. These results indicate that the marmoset BFCN display a significant and selective age-related loss of CB reminiscent of that observed in the human. Therefore, the common marmoset represents an appropriate animal model in which the consequences of BFCN CB loss can be investigated in depth. Loss of CB from the aged BFCN is likely to reduce the capacity of these neurons to buffer intracellular calcium and to leave them vulnerable to insults which can result in increased calcium levels. The vulnerability of the CB-negative BFCN in the aged marmoset to various insults which disturb calcium homeostasis remains to be investigated.

Aging↗

PubMed2001

Genomic and spectral analyses of long to middle wavelength-sensitive visual pigments of common marmoset (Callithrix jacchus).

The genetic basis of red-green color vision of common marmoset (Callithrix jacchus) is not fully understood. Here, we have cloned and characterized the three alleles at a locus that encode the long to middle wavelength-sensitive (LWS/MWS) visual pigments of this species. Using in situ hybridization, we localized this locus to the telomeric region of the long arm of X chromosome. The three visual pigments achieve the wavelengths of maximal absorption at 561, 553, and 539 nm and fully explain the red-green color vision of the common marmoset. The 'tri-allelic single-locus X-chromosome' model operates under the unique phenomenon, known as blood chimerism.

Animals↗

PubMed2003

Isolation of novel olfactory receptor genes in marmosets (Callithrix): insights into pseudogene formation and evidence for functional degeneracy in non-human primates.

Nineteen olfactory receptor (OR) genes were isolated from three OR subfamilies in two species of marmoset (Callithrix). Olfactory receptor 912-93 has high sequence similarity among marmosets and between marmosets and humans, suggesting strong conservation of function. All of the remaining seventeen OR genes identified from subfamilies 3A and 1E were pseudogenes. Following pseudogene formation, marmoset OR genes in both 1E and 3A subfamilies underwent duplications, indel events and a high rate of nucleotide substitution. These results provide a contrast to previous studies, and show that in spite of the keen olfactory sense of marmosets, they harbour many OR pseudogenes. A high rate of in vitro recombination using Pfu polymerase but not Taq polymerase was confirmed. The rapid molecular evolution of OR pseudogenes suggests that they do not provide a useful source of sequence variation for conversion to intact OR genes over evolutionary timescales. The overall pattern of OR evolution in marmosets is comparable to the 'birth-and-death' model of gene family evolution. An unbiased view on the evolutionary timing of the reduction of the functional olfactory repertoire in humans must await more data.

Animals↗

PubMed1998

Tularemia in a common marmoset (Callithrix jacchus) diagnosed by 16S rRNA sequencing.

We report a case of tularemia in a common marmoset (Callithrix jacchus) diagnosed by determination of the isolate's 16S ribosomal RNA (rRNA) gene sequence. Pathological examination of the animal revealed a multifocal acute necrotizing hepatitis, interstitial nephritis, splenitis, and lymphangitis of the mandibular, retropharyngeal, and cervical and mesenteric lymph nodes. Moreover, multiple foci of acute necrosis were found in the epithelium of the jejunum and the interstitium of the lung. Bacteriological investigations revealed a septicemia. The isolated infectious agent was uncommon, not routinely diagnosed in our laboratory and therefore difficult to identify by conventional tools in a reasonable time and effort. thus, we decided to perform a genetic analysis based on the 16S rRNA gene sequence. Thereby, an infection with Francisella tularensis, the causative agent of tularemia, was unambiguously diagnosed. This shows the great advantage 16S rRNA gene sequencing has as a general identification approach for unusual or rare isolates.

Animals↗

PubMed1998

Artificial insemination in Callithrix jacchus using fresh or cryopreserved sperm.

Assisted reproductive techniques are needed urgently to facilitate the captive breeding of many New World primate species which are endangered in the wild and to assist the effective genetic management of small colonies. A protocol was devised for artificial insemination in the common marmoset, Callithrix jacchus, using ejaculated sperm obtained by vaginal washing after copulation. A double insemination protocol was employed, with the first insemination taking place the day before ovulation was expected to occur and the second 48 h later. All six females inseminated with fresh ejaculated sperm became pregnant, delivering a total of 16 offspring at term. The gestation lengths and litter sizes were not statistically different from those observed in pregnancies following natural mating. The insemination protocol was adapted for use with cryopreserved ejaculated sperm by including an additional insemination on the day of expected ovulation, to take into account differences in the capacitation time of frozen-thawed sperm compared to fresh sperm. Three out of six females inseminated according to this triple insemination schedule, conceived, although one female subsequently resorbed twin foetuses approximately 100 days later. The remaining two pregnant females delivered four babies at term, one singleton and one set of triplets. In the final group, six females were inseminated with low doses of cryopreserved epididymal sperm using the same triple insemination protocol used for frozen-thawed ejaculated sperm. One female conceived, delivering triplets.

Animals↗

PubMed2000

Inducible nitric oxide synthase (iNOS) expression in liver and splenic T lymphocyte rise are associated with liver histological damage during experimental hepatitis A virus (HAV) infection in Callithrix jacchus.

Callithrix jacchus is considered a reliable animal model for hepatitis A virus (HAV) infection. All three HAV orally inoculated marmosets developed hepatitis - the infection was monitored by continuous virus shedding, high levels of serum enzyme alanine aminotransferase, specific antibody and seroconversion 3-6 weeks after HAV inoculation. HAV antigen was detected in liver by immunofluorescence 4 days post inoculation (PI) and onwards. To gain insight into the biological role of inducible nitric oxide synthase (iNOS) during immune-related acute liver injury the enzyme was searched in frozen biopsies: immunofluorescent labeling was found in the cytoplasm of liver cells mainly Kupffer's cells and spleen macrophages (CD68+) starting 11 days PI with maximum intensity on the fifth to sixth week PI. Necroinflammatory liver lesions characteristic of viral hepatitis were also observed at 10 days PI with maximum severity at 4 to 6 weeks PI. Furthermore, T lymphocytes (CD2+) were raised at this time point. No difference was evident in the frequency of B lymphocytes (CD20+). Therefore, iNOS expression preceded necroinflammatory liver lesion and maximal immunofluorescence reaction was coincident with tissue injury, supporting the hypothesis that NO contributes to hepatic cytotoxic mechanism but also to virus clearance. The concomitant rise in T-lymphocyte population may suggest a role for these cells in this and/or other independent HAV-induced pathological changes.

Animals↗

PubMed1993

Histopathological and immunohistochemical studies of hepatitis A virus infection in marmoset Callithrix jacchus.

Samples of serum, feces and liver tissue and organs of six cotton-eared marmosets Callithrix jacchus infected intravenously with two different strains of hepatitis A virus (HAV), were studied by conventional histologic techniques, by serological techniques and by immunocytochemical methods, such as immunofluorescence (IF) and peroxidase-antibody techniques. Hepatitis A antigen (HAAg) was detectable in daily collected stools, in liver biopsy obtained sequentially, and in organs collected at necropsy. Two marmosets also developed antibodies to HAV. By contrast, serum transaminases were not altered and there were histological hepatic lesions consistent with acute viral hepatitis in all inoculated animals. The data obtained, demonstrate that these primates are susceptible to human HAV and may be a useful animal model for the study of infection by this virus.

Animals↗

PubMed1995

Morphology of thyroid follicular cells from adult marmosets (Callithrix jacchus).

The existence of follicles with a "super flat" epithelium and the large number of primary and especially secondary lysosomes and lipofuscin granules in these cells are characteristic features of the thyroid gland of adult marmosets (Callithrix jacchus, new-world monkeys). It is supposed that these morphological findings are indications of a relatively low function and early ageing.

Animals↗