Terminal 13p deletion in squirrel monkey (Saimiri sciureus) with differentiated phenotype.

BACKGROUND: The taxonomic classification of squirrel monkeys is often controversial issue offering many different information. The classification of captive animals is difficult due to the phenotypic similarities between the presented species, which is observed mainly in coat coloration. METHODS: The objective of this study was to analyze the chromosome pattern of one squirrel monkey with off standard physical characteristics, which is kept in the Laboratory Animals Breeding Center in Rio de Janeiro State, Brazil, and try to establish some correlations. Chromosomes were obtained using lymphocyte culture technique. RESULTS AND CONCLUSIONS: Evaluation of G bands showed a terminal deletion in one chromosome of pair 13. The association of the results found with the different phenotypic characteristics led us to classify it as a Saimiri sciureus specimen with a structural chromosomal change, possibly allowing the expression of hemizygous alleles.

Spontaneous telangiectatic osteosarcoma in a rhesus macaque (Macaca mulatta).

Osteosarcoma (OS) is the most common type of bone cancer, especially in young. Telangiectatic osteosarcoma (TO) is a rare variant of OS, and hence, its occurrence, presentation, and prognosis are poorly understood. A 4-year-old female rhesus monkey presenting lameness and swelling was examined for a mass on the right humerus. Radiography revealed fracture and disorganized structure of bone tissue. Histopathological examination revealed malignant neoplasm composed of anaplastic osteoblasts, which invaded the bone marrow and surrounded blood-filled cysts in the epiphysis and diaphysis forming septa. Cytogenetic analysis showed aneuploid cells, supernumerary AgNORs, and a marker fragment. The neoplasm was diagnosed as TO. To our knowledge, the occurrence of TO and its cytogenetic analysis were reported for the first time in non-human primates.

Neotropical primate nursery in a squirrel monkey breeding unit in Brazil.

Saimiri (squirrel monkey) is a neotropical primate of the Simian genus that has been bred in captivity for the development of research into human and animal health. They have been widely used in studies in ophthalmology, toxicology, pharmacology, psychiatry, neuroscience, vaccines and drug tests (such as malaria and measles agents), as well as effects on interactive behavior and cognition of Creutzfeldt-Jakob disease in man. The main concern of non-human primate (NHP) research centers is focused on the establishment of self-sustaining breeding colonies providing good quality research animals. Maternal rejection, dystocia and pneumonia are the main causes of newborn deaths in these species. Therefore, in order to ensure the survival of these valuable animals, the Laboratory Animals Breeding Center of the Oswaldo Cruz Foundation (CECAL)/Fiocruz, Rio de Janeiro, Brazil, has developed a protocol for the nursery rearing of these infants.