Estimation of gestational ages in the common marmoset (Callithrix jacchus) from published prenatal growth curves

This report compares estimated gestational ages from published cubic spline curves to gestational ages estimated retrospectively from delivery dates in 28 pregnancies from ten common marmosets (Callithrix jacchus). Both CRL- and BPD-based estimates of gestational age were closely correlated with delivery-based gestational age estimates. Of the three ultrasound machines used, the one with 16 shades of gray and a sequential linear array overestimated gestational age during early pregnancy, based on CRL measures. Measures from the other two machines (64 or 264 shades of gray; linear sector and annular array or electronic phase array) were similar and resulted in a correlation of the two estimates of gestational age of 0.94 and a mean difference between the two estimates of 0.16 days with 80% of CRL-based gestational age estimates being within ± 5 days of the delivery-based estimate. The reliability of BPD-based estimates of gestational age was strongly related to pregnancy outcome. BPD-based estimates underestimated gestational age in poor outcome pregnancies (i.e., those in which infants died within 7 days of birth) but not in good outcome pregnancies. The combined CRL- and BPD-based estimates on poor outcome pregnancies suggest that there was less growth in BPD in late gestation for those pregnancies that resulted in nonviable offspring. For good outcome pregnancies, the correlation between BPD-based and delivery-based estimates of gestational age was 0.871 and the mean difference between the two estimates was ?0.06 days with 83.3% of BPD-based estimates falling within ± 5 days of delivery-based estimates.     

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.     

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.     

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.     

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.     

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.     

Non-invasive collection of ejaculates from the common marmoset (Callithrix jacchus) using penile vibrostimulation

Penile vibrostimulation (PVS), a noninvasive repeatable method, has been shown in the squirrel monkey to yield semen of higher quality than rectal probe electro-ejaculation (RPE). The present study aimed at establishing the conditions for PVS to collect ejaculates from marmoset monkeys. Ten adult males were trained on the appropriate handling before each was subject to six to 12 PVS tests. Ejaculation was stimulated using a FertiCare personal vibrator fitted with a 2 cm x 0.5 cm i.d. glass tube. The stimulus was repeatedly applied over a frequency of 75-95 Hz and amplitude of 1-2 mm for up to 20 min. Ejaculates were analyzed for volume, total sperm number, sperm concentration, and proportion of living and motile sperm. Ejaculates were obtained in 31 of 88 PVS tests; 87.1% of the ejaculations occurred at 80-85 Hz frequency and 1-1.5 mm amplitude. In 18 tests ejaculates were produced within 49.7 seconds. Ejaculates were characterized by (mean values): volume 31.9 microl, total sperm number 34.2 x 10(6)/ejaculate, concentration 1,154.2 x 10(6) sperm/ml, live sperm 74.6%, motile sperm 59.6%. Total number and concentration of spermatozoa were significantly enhanced in singly living males. PVS yielded three to four times more spermatozoa than comparable previously published values for RPE. Enhancing the success rate by preselecting males for responsiveness may render PVS the sperm collection method of choice in marmoset monkeys.     

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.     

Evaluation of vitamin D3 metabolites in Callithrix jacchus (common marmoset)

Vitamin D₃ (cholecalciferol) is endogenously produced in the skin of primates when exposed to the appropriate wavelengths of ultraviolet light (UV-B). Common marmosets (Callithrix jacchus) maintained indoors require dietary provision of vitamin D₃ due to lack of sunlight exposure. The minimum dietary vitamin D₃ requirement and the maximum amount of vitamin D₃ that can be metabolized by marmosets is unknown. Observations of metabolic bone disease and gastrointestinal malabsorption have led to wide variation in dietary vitamin D₃ provision amongst research institutions, with resulting variation in circulating 25-hydroxyvitamin D₃ (25(OH)D₃), the accepted marker for vitamin D sufficiency/deficiency. Multiple studies have reported serum 25(OH)D₃ in captive marmosets, but 25(OH)D₃ is not the final product of vitamin D₃ metabolism. In addition to serum 25(OH)D_3, we measured the most physiologically active metabolite, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), and the less well understood metabolite, 24,25-dihydroxyvitamin D₃ (24,25(OH)₂D₃) to characterize the marmoset's ability to metabolize dietary vitamin D₃. We present vitamin D₃ metabolite and related serum chemistry value colony reference ranges in marmosets provided diets with 26,367 (Colony A, N = 113) or 8,888 (Colony B, N = 52) international units (IU) of dietary vitamin D₃ per kilogram of dry matter. Colony A marmosets had higher serum 25(OH)D₃ (426 ng/ml [SD 200] vs. 215 ng/ml [SD 113]) and 24,25(OH)₂D₃ (53 ng/ml [SD 35] vs. 7 ng/ml [SD 5]). There was no difference in serum 1,25(OH)₂D₃ between the colonies. Serum 1,25(OH)₂D₃ increased and 25(OH)D₃ decreased with age, but the effect was weak. Marmosets tightly regulate metabolism of dietary vitamin D₃ into the active metabolite 1,25(OH)₂D₃; excess 25(OH)D₃ is metabolized into 24,25(OH)₂D₃. This ability explains the tolerance of high levels of dietary vitamin D₃ by marmosets, however, our data suggest that these high dietary levels are not required.     

Successful infection of the common marmoset (Callithrix jacchus) with human varicella-zoster virus.

The common marmoset, Callithrix jacchus, can be infected with human varicella-zoster virus (VZV), both wild-type strain KMcC and attenuated vaccine strain Oka/Merck. Infection was accomplished with either whole-cell-associated or cell extract VZV by combined oral-nasal-conjunctival application and was characterized by substantial and persistent anti-VZV antibody responses. The infectivity of VZV for marmosets was destroyed by treatment of inocula with heat or UV light. Diluted inocula with as few as 40 PFU/ml were infectious for marmosets. The lungs were demonstrated to be a major site of viral replication; both the presence of viral antigens and signs of pneumonia were demonstrated in lung tissues. Four serial passages of VZV KMcC were carried out in C. jacchus by a process of in vitro isolation and culturing of VZV from infected lung tissue and reapplication of the cultured isolates to fresh animals. The isolated viruses were identified as VZV both serologically and by restriction endonuclease analyses. The C. jacchus infectivity model should prove useful for determining the efficacy of subunit and live recombinant VZV vaccines as well as for the study of zoster.     

Relations among birth condition, maternal condition, and postnatal growth in captive common marmoset monkeys (Callithrix jacchus)

The present study characterizes the relations among maternal condition, litter size, birth condition, and growth in body weight for a population of common marmosets. The subjects of the study were marmosets born into a single colony between 1994 and 2001. Three sets of analyses were conducted to answer the following questions: 1) Is there a relationship between litter size, maternal condition, and birth condition? In the study population, maternal body weight, maternal age, litter size, and birth condition were related in a complex fashion. Birth weight and prenatal long‐bone growth, as reflected in knee–heel length, were both related to maternal age, with older mothers supporting higher prenatal growth. Age and maternal condition appeared to interact as determinants of long‐bone growth, as the combination of older and larger mothers resulted in significantly longer knee–heel lengths in their offspring. 2) Is there a relationship between birth condition or maternal condition and subsequent growth or final adult size? The early growth rate in this population was similar to early growth rates reported for three different marmoset colonies, suggesting that early growth may be relatively inflexible in this species. However, within this population, the variation that did occur in early growth rate was related to birth weight and maternal weight. Later growth and adult weight were related to birth weight and litter size: small twin infants displayed slower later growth rates and were smaller as adults than twins that began life at a higher birth weight, while the birth weight of triplets was not related to adult size. In these marmosets, small infants that were the result of increased litter size differed from small infants whose small birth size resulted from other factors. This reinforces the proposal that the causes of low birth weight will be relevant to the development of the marmoset as a model of prenatal environmental effects. Am. J. Primatol. 62:83–94, 2004. © 2004 Wiley‐Liss, Inc.     

Anaesthesia of the common marmoset (Callithrix jacchus) using continuous intravenous infusion of alphaxalone/alphadalone

A safe means of anaesthetizing common marmosets (Callithrix jacchus) for a study using magnetic resonance imaging (MRI) to investigate cerebral ischaemia was required. Continuous infusion of alphaxalone/alphadalone was used to anaesthetize 37 marmosets for non-recovery and recovery experiments. This was found to give safe, reliable anaesthesia when coupled with pulse oximetry and electrocardiographic (ECG) monitoring.     

Male parenting and response to infant stimuli in the common marmoset (Callithrix jacchus)

Callithrix jacchus infants are raised in complex family environments where most members participate in rearing the young. Many studies examining male parental behavior have focused on the carrying of infants with observations made within the family context. However, interference from family members can make it difficult to assess the father's motivation to care for infants. Our goals were to develop a testing paradigm for determining an individual's response to infant stimuli separate from family influences, compare a male's motivation to respond to an infant stimulus outside the family with his paternal behavior within the family, to compare responses to infant stimuli of parentally experienced versus inexperienced males and finally to develop a reproducible and standardized method of testing male responsiveness to infant stimulus that could serve to evaluate hormonal manipulations. Fifteen experienced common marmoset fathers were evaluated using three different measures of parental behavior: (1) instantaneous scan sampling, (2) continuous focal sampling in the family, and (3) continuous focal sampling of males presented with four infant stimuli: familiar and unfamiliar infants, familiar and unfamiliar infant vocalizations. Six parentally inexperienced males (non-fathers) served as controls. Males that carried the most in the family were typically the same males that responded most to the infant vocalization tests. Experienced fathers did not differ in their latency to enter the stimulus cage for any of the four infant stimuli response tests while inexperienced males took significantly longer to enter the stimulus cage. In addition, fathers expressed a greater frequency of infant-directed behavior than did the inexperienced males during the unfamiliar infant and unfamiliar vocalization tests. These studies show that experienced male marmosets are highly motivated to interact with infant stimuli and that there is interindividual variability in response to infant vocalizations. Testing males outside of the family allows for a clear assessment of male's interest in infant stimuli in both parentally experienced fathers and inexperienced males.     

Medial hypothalamic lesions and sexual receptivity in the female common marmoset (Callithrix jacchus)

Medial hypothalamic lesions cause major deficits in sexual receptivity in a variety of mammalian species. Effects of such lesions upon sexual receptivity in female primates have not been investigated. Two experiments are described in which thermal lesions were made in the hypothalamus in 11 ovariectomized or ovariectomized/adrenalectomized, oestradiol-treated common marmosets. Proceptivity (sexual initiating behaviour) was reduced or abolished by lesions in the dorsomedial or ventromedial hypothalamus. Sexual receptivity was unaffected except in 3 females in which damage to the ventromedial area was associated with a 25-42% increase in terminations of males' mounts. However, this effect was reversed by treating females with oestradiol. Therefore, medial hypothalamic lesions have pronounced effects upon proceptivity in the marmoset, whereas effects upon receptivity are much less pronounced or absent. These results are discussed in relation to the evolution of the hormonal control of receptivity in anthropoid primates as compared to other mammals.