Isolation, characterization and comparative aspects of the major serum apolipoproteins, B-100 and AI, in the common marmoset, Callithrix jacchus

The two major apolipoproteins of marmoset serum have been isolated and characterized, and on the basis of physicochemical and immunological criteria are homologous with the human AI and B-100 proteins. Marmoset apolipoprotein AI was the principal protein of high-density lipoproteins (HDL) and was purified by gel filtration chromatography and electrophoresis in alkaline-urea polyacrylamide gel followed by electrophoretic elution. Purified marmoset apolipoprotein AI displayed an Mr of approx. 27000, was polymorphic (five forms) on isoelectric focussing, with pI values in the range 4.8-5.0, and migrated similarly to human apolipoprotein AI in alkaline-urea gels. An overall resemblance was seen in the amino acid composition of marmoset apolipoprotein AI and that of its human counterpart with the notable exception that marmoset AI contained 1 isoleucine residue/mole. An immunological reaction of partial identity between the human and monkey proteins was seen upon immunodiffusion of their HDLs against antiserum to human apolipoprotein AI. Marmoset B-100 was the predominant apoprotein of VLDL and LDL, resembling the human protein in its elution profile on gel filtration chromatography in anionic detergent, and in its high apparent Mr (approx. 520000). The marmoset and human B-100 proteins were alike in amino acid composition and carbohydrate content. Moreover, their immunological behaviour with an antiserum to marmoset apolipoprotein B showed them to share certain antigenic determinant(s). We conclude that the physicochemical properties of the principle apolipoproteins of Callithrix jacchus, a New World primate, markedly resemble those of the human AI and B-100 proteins, suggesting therefore that they may function similarly in lipid transport and metabolism. Counterparts to human apolipoproteins AII, E, CII and CIII have also been tentatively identified.     

Handedness in the common marmoset (Callithrix jacchus)

For about 20 months the development of hand preferences in 21 experimentally naive common marmosets (Callithrix jacchus) was examined in 15 different tests. Test preferences were compared with their spontaneous behavior preferences in such contexts as feeding, grooming, play, and others. In the spontaneous use of the hands, only eight animals showed a significant lateral preference (2 left-handed, 6 right-handed). During the test period, however, the number of handed marmosets increased to 19 (5 left-handed, 14 right-handed). Most of the animals fluctuated considerably in their preference levels, a situation which led to a remarkable test response inconsistency of handedness. When the test situation was changed, complete reversals of handedness were more frequent than weakening or strengthening of a particular preference. The animals' emotions during the test session and environmental variables affected handedness significantly. None of the tested marmosets showed an increase of hand preference from the first to the last test. Our results indicate that Callithrix is ambidextrous rather than handed.     

Sex determination in the common marmoset (Callithrix jacchus).

The general morphology of the external genitalia was examined in 43 common marmosets (Callithrix jacchus) ranging in age from newborn to adult. At birth, the scrotum was a small irregular fold of skin on either side of the caudal aspect of the penis. The testes were not present in the scrotum until 8--11 months of age. The scrotum covered the penis in the adult male, was devoid of fur, was covered by pearly while nodules, and presented a median raphe. In the young female, the pudendal pad closely resembled the scrotum of the male. The vulva was pendulous, and the small vestibular opening was located near its most ventral aspect and closely resembled the preputial opening of the male. In the adult female, the pudendal pad was pendulous, was studded with white nodules, and closely resembled the scrotum of the male. Sex determination by casual observation resulted in numerous errors. Accurate sex determination was based on differences in the preputial and vestibular openings, demonstration of the glans penis in the prepuce, and palpation of the testes in the scrotum or inguinal region.     

Field observations on group size and composition of the common marmoset (Callithrix jacchus jacchus), at Tapacura,Brazil

A five and a half month field study on the common marmosetCallithrix jacchus jacchus, was carried out during the dry season at Tapacura near Recife, Brazil. Twelve groups were counted and group sizes ranged between 3 and 13 animals. The age/sex class composition of three groups was determined by observation of one group and by trapping two others. Five groups were counted over a period of five months and one group over four months, during which two confirmed cases of immigration into groups were observed. The evidence for birth seasonality is considered. Data are presented to support the hypothesis that there is only one breeding female per group, although a group containing two mature females was observed. The observations are compared with those obtained for other Callitrichid species.     

Patterns of prenatal survival in the common marmoset (Callithrix jacchus)

Abstract: Fifty common marmoset pregnancies were monitored using ultrasound. The objective was to ascertain if fetal mortality was related to litter size. Prior to analysis we determined abortion rate and litter size were not influenced by repeated ultrasound. Mortality was unrelated to litter size and occurred fairly late in gestation. All singletons born in this study began gestation as twins. It is hypothesized that marmosets may be able to adjust litter size late in pregnancy in response to proximate environmental factors.     

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.     

An experimental analysis of social interaction in the common marmoset (Callithrix jacchus jacchus)

Adult and juvenile common marmosets were introduced to unfamiliar conspecifics individually and in whole groups. In introductions using animals of the same sex, adults were mutually hostile unless they were related or socially familiar; juveniles behaved submissively to adults and little aggression was observed between juveniles. In introductions using animals of the opposite sex, males of all ages solicited females but females did not reciprocate. When whole groups were introduced, in two experiments most of the elder group members behaved aggressively and younger animals did not interact frequently; but in a third experiment, in which the adult males were related, little aggression was observed and younger animals behaved amicably. It is argued that the behavioral reactions shown by individual marmosets are related to territorial hostility and that the behavior of juveniles to adults may aid assimilation of younger animals into new groups.     

A lobster claw abnormality in the common marmoset (Callithrix jacchus)

A congenital abnormality of the digits, similar to the 'lobster claw' deformity of humans, was observed in 8 common marmosets. The condition varied in severity and in effect on the animals; it appeared to be due to a single autosomal recessive trait.     

Congenitally caused fused labia in the common marmoset (Callithrix jacchus)

In this paper, the occurrence of an external genital abnormality in female marmoset monkeys (fused labia) is discussed. This malformation was detected, for the first time, in a group of animals at the German Primate Center (GPC), Goettingen. The malformed vulva was completely sealed except for an opening of 1.5-2.5 mm around the urethra sufficient for urination. Because of this defect the animals were not able to copulate. As a consequence, the affected females were functionally infertile although they had a normal genital tract and a regular cycle. This vulvar abnormality was found in 12 females, offspring of 10 pairs in which either one or both came to the German Primate Center from two genetically related colonies in Munich, Germany, and one colony in Basel, Switzerland. The abnormality appeared to be recessive and inheritable from either parent. In pairs in which both animals were from one of the mentioned colonies, 45% of the female offspring were affected. In pairs where only one partner came from these colonies, 26% of female offspring had the malformation. These results indicate that avoidance of inbreeding, which is frequently performed in primate colonies, may reduce, but not eliminate the expression of abnormalities of genetic origin. Therefore selective breeding is required, and, in colonies where these recessive mutations are widespread, the development of genetic screening tests would be advantageous.     

Characterization of the expressed immunoglobulin IGHV repertoire in the New World marmoset Callithrix jacchus

The common marmoset (Callithrix jacchus jacchus) is a member of the Callithrichinae, a family of outbred New World primates with limited MHC polymorphisms and a propensity to develop spontaneous or experimentally induced autoimmunity. C. jacchus marmosets are susceptible to experimental allergic encephalomyelitis (EAE), and spontaneously develop autoimmune colitis and thyroiditis. Such disease models approximate the complexity of human autoimmune disorders, and allow an investigation of the respective roles of T-cell and antibody responses to self-antigens in outbred species. A key issue for further definition of the pathogenic antibody responses in human autoimmunity is to understand the diversity of the immunoglobulin repertoire in primate models. Here, we characterized the expressed immunoglobulin IGHV repertoire of the C. jacchus marmoset. Six IGHV subgroups were identified which show a high degree of sequence similarity to their human IGHV counterparts (IGHV1, IGHV3, IGHV4, IGHV5, IGHV6, and IGHV7). As in the expressed human IGHV repertoire, the framework regions are more conserved when compared to the complementarity-determining regions (CDRs), with the greatest degree of variability located in CDR3. Predicted structural features are highly conserved between C. jacchus and human IGHV. This information now provides a framework for studies of the antigen-specific repertoire of pathogenic antibodies in EAE and other immune-mediated diseases.     

Chimaeric and constitutive DNA fingerprints in the common marmoset (Callithrix jacchus)

Marmosets normally produce dizygotic twins sharing placental blood vessels and exchanging bone marrow cells. Each individual is therefore likely to be a blood chimaera. To date, marmosets had only been DNA fingerprinted using blood samples and probes 33.6 and 33.15, resulting in highly similar fingerprints among litter mates and little variation between other individuals, thereby limiting this method's use for individual identification and parentage testing. In this study, novel probes were applied to detect greater polymorphism and to produce individual-specific DNA fingerprints. As expected, blood DNA profiles of twins and triplets were virtually identical, confirming chimaerism in this tissue and identifying litter mates. Furthermore, these profiles were sufficiently variable to distinguish between sibs from different litters and between all other individuals. To produce individual-specific DNA fingerprints, the use of DNA extracted from tissues poor in leukocytes was essential. The findings demonstrate that, despite extensive blood chimaerism, marmoset colonies can be effectively DNA fingerprinted for indicidual identification, zygosity testing, and relationship studies.     

Suboccipital puncture for cerebrospinal fluid in the common marmoset (Callithrix jacchus)

Cerebrospinal fluid (CSF) can be obtained routinely from the common marmoset (Callithrix jacchus) by suboccipital puncture. One field of research in which this method is applied is the detection of changes in the biogenic amine metabolism in CSF. The puncture technique is simple and rapid and does not injure the experimental animal.     

Systems for collection of urine in the captive common marmoset, Callithrix jacchus

Two systems are described for the collection of 24 h urine samples from the common marmoset (Callithrix jacchus). Using 84 adult animals, 1210 24-h samples were collected. Mean urinary excretion was 14.4 +/- 7.5 ml/24 h (n = 1210, mean +/- SD). No differences were observed between sexes (for 52 females, 24 h volume = 15.1 +/- 8.0 ml; for 32 males, 24 h volume = 12.5 +/- 6.0 ml). No significant differences were observed between pregnant and non-pregnant females with respect to 24 h urine volume, and bilateral gonadectomy did not influence subsequent urinary excretion in either sex. For 161 pairs of observations, the intake of drinking water (11.7 +/- 10.2 ml/24 h) and the volume of urine excreted (12.6 +/- 7.1 ml/24 h) showed a positive correlation (r = 0.406 d.f. 159, P less than 0.001: y = 0.558x + 4.247).     

Increased ACTH and cortisol secretion after interleukin-alpha injection in the common marmoset (Callithrix jacchus jacchus)

We have studied the effect of intravenous injection of interleukin-1 (dose range: from 0.25 to 4.5 microg/kg of body weight) on plasma ACTH and cortisol levels in the marmoset, a primate paradygm of peripheral glucocorticoid resistance. Blood sampling were collected and body temperature recorded 0, 15, 30, 60, 120, 180, 240 and 300 min after injection. Interleukin-1 stimulated secretion of ACTH in a dose-dependent fashion. Maximal secretion occurred 120 min after injection, and lasted up to 240 min. Plasma ACTH levels returned to baseline 300 min after interleukin-1 injection. Plasma cortisol levels were related to ACTH levels. Body temperature elevation, which occurred 10-15 min after injection was dose-dependent, and lasted 3 h. Results suggest that the pyrogenic effect of interleukin is associated, in the marmoset, with integrated activation of the hypothalamic-pituitary-adrenal axis. In light of the proneness of marmosets to hyperimmune disorders, our data are consistent with the hypothesized central biological role of IL-1, as well as the pathophysiological relevance of the neuro-endocrine-immune cross-talk during the acute phase response.     

Cemented annulation as an age criterion in the common marmoset (Callithrix jacchus)

Teeth from 18 marmosets, seven months to 5.8 years of age, were studied histologically. A minimum of one dark and one light band comprised one cemental annulation. Age was estimated by counting the number of annulations and adding four months to premolar and eight months to canine teeth for tooth development. Cemental annulations were most consistent near the gingival border on the labial aspect of the tooth. The method will be valuable in estimating the ages of marmosets and other nonhuman primates.