A restraint system for the common marmoset (Callithrix jacchus)

A method for restraining the marmoset in a primate chair is described. The device is inexpensive to construct, is reliable, and the majority of animals can be habituated to its use. The chair has been used in neurobiological studies employing electrophysiological recordings, with or without concurrent collection of serial blood samples.     

Age determination of common marmosets (Callithrix jacchus) by radiographic examination of skeletal development

Seventy-four animals were examined radiographically to determine the skeletal development of the common marmoset (Callithrix jacchus) from 6 months of age. Twenty-one epiphyses were examined and five stages of ossification were described for each. The animals were divided into nine groups, according to age, and a table of the stage of ossification and age was produced, which may be used for determining the age of animals of unknown history.     

Hybridization effects and genetic diversity of the common and black‐tufted marmoset (Callithrix jacchus and Callithrix penicillata) mitochondrial control region

Hybridization is continually documented in primates, but effects of natural and anthropogenic hybridization on biodiversity are still unclear and differentiating between these contexts remains challenging in regards to primate evolution and conservation. Here, we examine hybridization effects on the mitochondrial DNA (mtDNA) control region of Callithrix marmosets, which provide a unique glimpse into interspecific mating under distinct anthropogenic and natural conditions. DNA was sampled from 40 marmosets along a 50‐km transect from a previously uncharacterized hybrid zone in NE Brazil between the ranges of Callithrix jacchus and Callithrix penicillata. DNA was also collected from 46 marmosets along a 30‐km transect in a hybrid zone in Rio de Janeiro state, Brazil, where exotic marmosets appeared in the 1980s. Combining Callithrix DNA sampled inside and outside of these hybrid zones, phylogenetic and network analyses show C. jacchus and C. penicillata being parental species to sampled hybrids. We expand limited Callithrix population genetics work by describing mtDNA diversity and demographic history of these parental species. We show ancient population expansion in C. jacchus and historically constant population size in C. penicillata, with the latter being more genetically diverse than the former. The natural hybrid zone contained higher genetic diversity relative to the anthropogenic zone. While our data suggest hybrid swarm formation within the anthropogenic zone due to removed physical reproductive barriers, this pattern is not seen in the natural hybrid zone. These results suggest different genetic dynamics within natural and anthropogenic hybridization contexts that carry important implications for primate evolution and conservation. Am J Phys Anthropol 155:522–536, 2014. © 2014 Wiley Periodicals, Inc.     

Clinical care and diseases of the common marmoset (Callithrix jacchus)

The common marmoset (Callithrix jacchus) is a small New World primate that is native to eastern Brazil and has been used in biomedical research since the early 1960s. Use of this species for research purposes continues to grow at a rapid pace as they are a viable alternative to other nonhuman primate species. We discuss clinical care, such as preventative medicine, anesthesia, and routine clinical procedures. Important viral, bacterial, parasitic, and gastrointestinal tract diseases are discussed, with relevant details on cause, transmission, pathologic changes, diagnosis, and treatment. Current problems affecting marmoset health and research in the modern vivarium are emphasized.     

Morphological changes of the ovary and hormonal changes through the ovarian cycle of the common marmoset (Callithrix jacchus)

Laparoscopic observations of morphological changes of the ovary during the ovarian cycle in conjunction with radioimmunoassay of serum progesterone and estradiol-17β was investigated as a method of monitoring the ovarian cycle in the common marmoset. In the common marmoset, plural follicles first appeared in each ovary five days prior to ovulation. At three to four days prior to ovulation one or two follicles developed into translucent blisters on the surface of the ovary. As the follicles filled with follicular fluid, they became larger and clearer until one to two days prior to ovulation, at which time they formed well defined, transparent bubbles protruding from the surface of the ovary. After ovulation, the ovulation point could be detected at the center of the follicle, sometimes surrounded by a corpus of engorged blood vessels. Ovulations of the plural follicles were not simultaneous, and due to the time lag ovulations took at least 12 to 20 hrs in four out of seven animals examined. After two to five days of ovulation the corpus hemorragicum, a bright red protrusion made of tissue and blood disrupted by ovulation, was found. Subsequently, the color of the formatted corpus luteum changed from dark-red to yellow then to yellow white. While the corpus luteum remained reddish in color serum progesterone was maintained at as high levels as in the luteal phase. There was no mature follicle or corpus luteum in subordinate female ovaries.     

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.     

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.     

The fertility of daughters in common marmoset (Callithrix jacchus jacchus) family groups

Observations previously made in the field of inter-group mating raised questions concerning the fertility of daughters in family groups and about possible competition between mothers and daughters. To test whether daughters in captive family groups could become pregnant, daughters from four groups were placed with a strange male for a period of 30 min, twice a week for eight weeks. No changes were observed in the mother/daughter interactions during the time in which the daughters were allowed contact with the strange male. Two of the daughters showed signs of ovulation and the male only copulated with these animals. One daughter became pregnant, but it was aggression with her siblings rather than her mother which necessitated removing her from her family group.     

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.     

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.     

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.     

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.     

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).     

Endogenous N-excretion and minimal protein requirement for maintenance of the common marmoset (Callithrix jacchus)

The protein requirement for maintenance of the marmoset Callithrix jacchus was investigated by factorial calculation via the N balance technique. Six adult male marmosets were fed a protein-free pelleted diet for 22 days. When a low protein diet (6%) was fed in the preperiod, only 7 days were necessary and when fed a higher protein diet (18%) 10 days were necessary to reach a minimum of N excretion during protein depletion. Body weight losses averaged 11% and food intake was 21% lower in the protein free period. The average endogenous urine N (EUN) was 62.1 mg N and endogenous fecal N (EFN) 49.2 mg N/kg W0.75. Body surface losses (BSN) were assumed to be 20 mg N/kg W0.75. The total endogenous loss of 131.3 mg N/kg W0.75 is similar to that of other species. Net protein utilization (NPU) of well balanced proteins, determined near the N equilibrium, was 51.8%. The calculated net protein requirement amounts to 313.6 mg N/kg W0.75, which corresponds to a dietary protein content of 6% in a diet of high caloric density, (about 19-20 MJ/kg dry matter) when the food intake is 3.3% of body weight.