Biomaterial Database

The Amazon molly, Poecilia formosa, as a test animal in carcinogenicity studies: chronic exposures to physical agents. 1984

A D Woodhead, and R B Setlow, and V Pond

The Amazon molly, Poecilia formosa, a small, live-bearing fish native to Texas, has an unusual mode of reproduction that makes it highly suitable for carcinogenicity studies. The species is easy to rear and breed, and withstands handling well. Large broods of young are born, numbering up to 90 when the parent fish are fully grown. The Amazon molly reproduces gynogenetically; eggs are activated after mating with males of closely related species. The male makes no genetic contribution; sperm provides only the stimulus for egg development. The offspring of a female comprise a clone with genotypes identical to that of the mother's so that cell and tissue transplants made between members of the clone are not rejected. We used the Amazon molly as an animal model to show that damage to DNA caused by UV and ionizing radiation and by certain chemicals results in tumor development. Thyroid cells were taken from donor mollies, treated precisely in vitro with the agents, and then injected into homologous recipients. Eight months later, recipient fish had developed large thyroid tumors. The genetic homogeneity of the clone also makes the Amazon molly invaluable in acute or chronic bioassays because variability in the responses of the individual fishes is minimal. Therefore, a limited number will suffice to give statistically significant results. The findings from a study of chronic exposure to asbestos are also described.

UI	MeSH Term	Description	Entries
D010312	Parthenogenesis	A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.	Arrhenotoky,Automixis,Thelytoky,Parthenogeneses
D002244	Carbon	A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.	Carbon-12,Vitreous Carbon,Carbon 12,Carbon, Vitreous
D002273	Carcinogens	Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.	Carcinogen,Oncogen,Oncogens,Tumor Initiator,Tumor Initiators,Tumor Promoter,Tumor Promoters,Initiator, Tumor,Initiators, Tumor,Promoter, Tumor,Promoters, Tumor
D003365	Costs and Cost Analysis	Absolute, comparative, or differential costs pertaining to services, institutions, resources, etc., or the analysis and study of these costs.	Affordability,Analysis, Cost,Cost,Cost Analysis,Cost Comparison,Cost Measures,Cost-Minimization Analysis,Costs and Cost Analyses,Costs, Cost Analysis,Pricing,Affordabilities,Analyses, Cost,Analyses, Cost-Minimization,Analysis, Cost-Minimization,Comparison, Cost,Comparisons, Cost,Cost Analyses,Cost Comparisons,Cost Measure,Cost Minimization Analysis,Cost, Cost Analysis,Cost-Minimization Analyses,Costs,Measure, Cost,Measures, Cost
D005075	Biological Evolution	The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.	Evolution, Biological
D005399	Fishes	A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000822	Animal Husbandry	The science of breeding, feeding and care of domestic animals; includes housing and nutrition.	Animal Husbandries,Husbandries, Animal,Husbandry, Animal
D001194	Asbestos	Asbestos. Fibrous incombustible mineral composed of magnesium and calcium silicates with or without other elements. It is relatively inert chemically and used in thermal insulation and fireproofing. Inhalation of dust causes asbestosis and later lung and gastrointestinal neoplasms.
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor