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PubMed1989

[Ultrastructure of the gastrointestinal epithelium in the marmoset (Callithrix jacchus)].

The epithelium of the stomach and intestine of one and three days old as well as adult marmosets was investigated using transmission electron microscopy and was compared with already existing data of man and the laboratory rodents, rat, mouse and guinea-pig. On postnatal day (PD) 1, the enterocytes possessed an inframicrovillous membrane system and giant lysosomes which were absent in adult marmosets whereas the surface and glandular epithelial cells of the stomach showed all structures which were also typical for adult animals. Enterocytes rich in fat and glycogen were only present on PD 1. In the large intestine the vacuolated cells were more frequently seen on PD 1 and 3 than in adult marmosets. The endocrine cells of newborn animals corresponded to those in the gastric and intestinal epithelium of mature animals, occurred everywhere in the lower digestive tract and could be subdivided at least into EC, ECL, D and L and EG cells respectively; a further subdivision was not possible by conventional transmission electron microscopy. Compared with rats, mice and guinea-pigs mostly used for developmental studies of the digestive tract, marmoset monkeys differed especially from the gastrointestinal epithelium of rats and mice but also from guinea-pigs. By contrast comparisons with the human situation are difficult due to the lack of representative electron microscopic findings on the gastrointestinal epithelium. If one considers the close phylogenic relationship between marmosets and man, the marmoset data should be transferable to the human situation rather than the findings obtained for rats, mice and guinea-pigs. In the epithelium of the adult gastrointestinal tract clear-out ultrastructural differences could not be found between these species.

Animals↗
PubMed1988

Effect of iodine deficiency on craniofacial growth in young common marmosets (Callithrix jacchus).

The effects of iodine deficiency on general and craniofacial growth were determined in young common marmosets. Examinations, including direct measurement, cephalometric radiology, and dental examination, were performed at three-month intervals from birth to 1 year on a cross-sectional sample of three groups of marmosets. The groups were those on a normal diet, n = 50; an iodine-deficient diet during gestation and for 1 year postnatally, n = 26; and an iodine-deficient diet only during gestation (returned to a normal diet at 1 month after birth), n = 18. The iodine-deficient animals were smaller in all dimensions, compared with controls, but they did not have typical cretin facies. Animals that were iodine deficient during gestation but subsequently fed a normal diet were small initially but displayed compensatory growth, so that by 1 year they were nearly normal in size.

Age Factors↗
PubMed1985

Oculomotor areas involved in the parasympathetic control of accommodation and pupil size in the marmoset (Callithrix jacchus).

The motoneurons of the oculomotor complex responsible for controlling accommodation and pupil size of the marmoset were identified by injecting horseradish peroxidase (HRP) into the ciliary ganglion. The anatomical organization of accommodation and pupil constrictor motoneurons was determined using electrical stimulation techniques. HRP-labelled cells were found through the whole length of the Edinger-Westphal nucleus (EW) and also just ventral to this nucleus in caudal sections. A projection from the antero-median nucleus to the ciliary ganglion could not be demonstrated. Electrical stimulation data showed that currents of less than 1 microampere applied inside the EW evoked accommodation responses. Pupil constriction responses, on the other hand, were evoked with weak currents at sites ventral to those in the EW generating accommodation at caudal and central levels. It was concluded that the EW was responsible for accommodation and areas containing HRP-labelled cells ventral to the caudal part of the EW were responsible for pupil constriction.

Accommodation, Ocular↗
PubMed1985

Haematological characteristics of the common marmoset (Callithrix jacchus jacchus).

Blood cell indices and parameters of haemostasis were studied in the common marmoset. The majority of the results were similar to those found in man. Differences from man were that the prothrombin time was shorter in the marmoset, higher concentrations of aggregating stimuli were required to cause platelet aggregation, and marmoset platelets did not aggregate under the influence of adrenalin. There was sexual dimorphism evident in the data for fibrinogen concentration and for platelet count, both of which were higher in females than in males. Marmoset platelets were very similar in ultrastructure to those of man.

Animals↗
PubMed1983

Radiographic evaluation of appendicular skeletal maturation in the common marmoset (Callithrix jacchus).

The thoracic appendicular skeletal development of five common marmosets was monitored radiographically at weekly intervals from 1 day to 94 weeks of age and the times of appearance and fusion of 47 ossification centers were recorded. A range and average age for the appearance and fusion of each ossification center were calculated and compared to data available for the rhesus monkey and man.

Animals↗
PubMed1983

A comparison of craniofacial growth between two colonies of marmosets (Callithrix jacchus).

General and craniofacial measurements from young marmosets in a recently established Australian colony are presented and compared with similar data published for a long-established colony in the United Kingdom. Statistically significant differences between the colonies were those associated with large error variances, suggesting difficulties in locating certain landmarks rather than real differences in growth. Thus, direct comparison can be made between craniofacial growth studies conducted at these two different marmoset colonies.

Analysis of Variance↗
PubMedDate not supplied

Influence of semen collection method on ejaculate characteristics in the common marmoset, Callithrix jacchus.

A source of normal spermatozoa (sperm) is required for many andrological and reproductive studies. Ideally the method used for semen collection should be repeatable and reliable but should not influence sperm characteristics or sperm function. Two methods of semen collection from marmosets, vaginal washing after copulation and electroejaculation, were compared in terms of the success rate in obtaining samples and the characteristics of the sperm suspensions. Vaginal washing was shown to be a reliable, repeatable, and apparently non-stressful method of obtaining ejaculates, with 8 out of 10 males ejaculating on at least four of the five attempts. The semen was of good quality as assessed by conventional means, and the sperm were highly fertile when used for artificial insemination (Al; 100% conception rate). In contrast, fewer ejaculates were obtained from the same males by electroejaculation (success rate 30%), sperm survival in vitro was reduced compared to sperm collected by vaginal washing (0.93 +/- 0.15 days for electroejaculated sperm compared to 1.98 +/- 0.3 days for sperm from vaginal washing), and the number of animals giving birth after Al was smaller (0 vs. 6; P < 0.05). The proportions of motile (74.8 vs. 70.7%), live (84.7 vs. 81%), and morphologically normal (91.9 vs. 87.6%) sperm in the ejaculates were not affected by the semen collection method, but velocity parameters, such as curvilinear velocity, straight line velocity, and average path velocity, as assessed by computerized motility analysis, were significantly lower in vaginal washings than in electroejaculates (P < 0.023, 0.008, and 0.008, respectively). Mean angular deviation and beat cross frequency were greater in vaginal washings than in electroejaculates (P < 0.016 and 0.008, respectively). Therefore the effect of semen collection method on sperm function should always be considered when designing reproductive studies.

Animals↗
PubMed1996

Gongylonematiasis in the common marmoset (Callithrix jacchus).

Two cases of gongylonematiasis in common marmosets of two research facilities in Germany are reported. The helminthiasis was transmitted from colony A to colony B by one infected female and within colony B by cockroaches (Blatella germanica). Four of 40 cockroaches examined in colony B were infected with rhabditiform larvae. Clinical signs of disease in the infected animals consisted of intense itching and scratching of the edematous and slightly hyperemic perioral tissues. Histologically the adult helminths lodged predominantly in the mucous membranes of the upper and lower lips; they were less frequently present in the labial cutaneous parts or in the tongue and could not be seen in the esophageal wall, bronchi, or abdominal organs. The helminthic infection probably caused minor to moderate mixed inflammatory infiltrates of the periesophageal connective tissues and intense inflammation of the deep lingual muscular tissues. Lesions of the mucosal membranes of the lips and tongue had predominant accumulations of neutrophilic granulocytes, lymphocytes, and mostly degranulated mast cells with only a few eosinophilic granulocytes. In the cutaneous part of the lips multifocal microabscesses were considered to be secondary lesions from the intense scratching.

Animals↗
PubMed1998

Visuotopic organisation and neuronal response selectivity for direction of motion in visual areas of the caudal temporal lobe of the marmoset monkey (Callithrix jacchus): middle temporal area, middle temporal crescent, and surrounding cortex.

On the basis of extracellular recordings in marmoset monkeys, we report on the organisation of the middle temporal area (MT) and the surrounding middle temporal crescent (MTc). Area MT is approximately 5-mm long and 2-mm wide, whereas the MTc forms a crescent-shaped band of cortex 1-mm wide. Neurones in area MT form a first-order representation of the contralateral hemifield, whereas those in the MTc form a second-order representation with a field discontinuity near the horizontal meridian. The representation of the vertical meridian forms the border between area MT and the MTc. In both areas, the fovea is represented ventrocaudally, and the visual field periphery is represented dorsorostrally. Analysis of single units revealed that 86% of cells in area MT show a strong selectivity for the direction of motion of visual stimuli. The proportion of direction-selective cells in the MTc (53%), whereas lower than that in area MT, is much higher than that observed in most other visual areas. Neurones in the cortex immediately rostral to area MT and the MTc are direction selective, with receptive fields predominantly located in the visual field periphery. In contrast, only a minority of the cells in the cortex ventral to the MTc are direction selective, and their receptive fields emphasise central vision. The results suggest that the MTc is functionally closely related to area MT, and distinct from the areas forming the dorsolateral complex. The MTc may have a role in combining information about motion in the visual field, processed by area MT, with information about stimulus shape, processed by the dorsolateral complex.

Animals↗
PubMed1998

Immunoreactive riboflavin carrier protein concentration during ovulatory cycle in the common marmoset (Callithrix jachhus): role of estrogen.

Common marmoset, a non-human primate, is increasingly being used as a model system in reproductive endocrinology. Marmosets do not menstruate but have normal cycle length of 28 +/- 2 days. The presence of protein immunologically and functionally similar to the well characterized chicken riboflavin carrier protein (cRCP) has been demonstrated in circulation in pregnant marmosets. Marmoset RCP (mRCP) has been partially purified and the molecular weight of the immunoreactive protein is similar to cRCP. The source of RCP in rodents appears to be maternal liver, suggesting thereby that RCP levels could be modulated by changing hormonal pattern that occurs during the cycle. To study the hormonal control of marmoset RCP, immunoreactive RCP levels were monitored during normal cycle. Plasma progesterone was estimated by RIA and mRCP was measured using a heterologous cRCP RIA. When mRCP and progesterone were analysed for a period of 40 days (n = 5) in adult females, very low amount of mRCP was measured during the luteal phase and a single sharp peak was observed during the follicular phase of the cycle. These data suggested that the induction of mRCP was regulated by estrogen. Direct evidence for the role of estrogen in the elaboration of RCP, was the observation that exogenous administration of estradiol 17 B to immature marmosets resulted in a time and dose dependent increase in plasma RCP levels. As early as 24 hr following hormonal administration, a measurable increase in mRCP with a maximum increase, 5-fold over the zero period was seen 3 days following a single administration of estradiol 17 B (5 mg/kg body wt). RCP levels declined thereafter and was indistinguishable by day 7. These studies indicate that the marmoset RCP levels are regulated by estrogen.

Animals↗