Hostname: page-component-77c89778f8-vpsfw Total loading time: 0 Render date: 2024-07-16T18:01:32.408Z Has data issue: false hasContentIssue false

The control of body size in mouse chimaeras

Published online by Cambridge University Press:  14 April 2009

D. S. Falconer
Affiliation:
Agricultural Research Council Unit of Animal Genetics*
I. K. Gauld
Affiliation:
Agricultural Research Council Unit of Animal Genetics*
R. C. Roberts
Affiliation:
Agricultural Research Council Unit of Animal Genetics*
D. A. Williams
Affiliation:
Department of Statistics, University of Edinburgh

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Aggregation chimaeras were made from embryos of strains of mice selected for large and small body size and of unselected controls. The strains were combined in pairs marked by albino coat colour and by allo-zyme variants at the Gpi-1 locus. The proportion of cells derived from each component was scored visually in the coat melanocytes and by electrophoresis in ten other organs or tissues (blood, liver, lung, spleen, spinal cord, brain, pituitary, kidney, adrenal and testis). The object was to find out how body weight is related to cell proportions in the body as a whole and in the separate organs. Individuals varied widely in their mean cell proportions but there were significant differences between organs within individuals. Body weight was linearly related to the mean cell proportions which accounted for most, or possibly all, of the chimaeric variance of body weight. No one of the organs studied could be identified as being solely responsible for growth control, or as having a predominant influence on growth. The weights of some organs were probably influenced to a small extent by their own cell proportions independently of the individual's mean, but the differences of body weight were too great to be accounted for by the summation of localized effects on organs. The mean cell proportion, averaged over individuals, was close to 50%, proving that there was no tendency for cells from the larger component to outgrow those from the smaller. It is concluded that growth control must be systemic, but it was not possible to decide whether the systemic effect comes from some particular organ not studied, or is in some undefined way the consequence of the cell proportions in the body as a whole. There was some evidence, though it was inconclusive, that chimaeras show ‘heterosis’ for body weight.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1981

References

REFERENCES

Bowman, P. & McLaren, A. (1970). Viability and growth of mouse embryos after in vitro culture and fusion. Journal of Embryology and Experimental Morphology 23, 693704.Google ScholarPubMed
Falconer, D. S. (1973). Replicated selection for body weight in mice. Genetical Research 22, 291321.CrossRefGoogle ScholarPubMed
Falconer, D. S. & Avery, P. (1978). Variability of chimaeras and mosaics. Journal of Embryology and Experimental Morphology 43, 195219.Google ScholarPubMed
Falconer, D. S., Gauld, I. K. & Roberts, R. C. (1978 a). Growth control in chimaeras. In Genetic Mosaics and Chimaeras in Mammals (ed. Russell, L. B.), pp. 3949. New York: Plenum Press.CrossRefGoogle Scholar
Falconer, D. S., Gauld, I. K. & Roberts, R. C. (1978 b). Cell numbers and cell sizes in organs of mice selected for large and small body size. Genetical Research 31, 287301.CrossRefGoogle ScholarPubMed
Garnett, I. & Falconer, D. S. (1975). Protein variation in strains of mice differing in body size. Genetical Research 25, 4557.CrossRefGoogle ScholarPubMed
Gauld, I. K. (1980). Prenatal growth and development in fast and slow growing strains of mice. Ph.D. Thesis, University of Edinburgh.Google Scholar
Klebe, R. J. (1975). A simple method for the quantitation of isozyme patterns. Biochemical Genetics 13, 805812.CrossRefGoogle ScholarPubMed
McLaren, A. (1976). Mammalian Chimaeras. Cambridge University Press.Google Scholar
Moore, W. J. & Mintz, B. (1972). Clonal model of vertebral column and skull development derived from genetically mosaic skeletons in allophenic mice. Developmental Biology 27, 5570.CrossRefGoogle ScholarPubMed
Nesbitt, M. N. (1978). Attempts at locating the site of action of genes affecting behaviour. In Genetic Mosaics and Chimaeras in Mammals (ed. Russell, L. B.), pp. 5158. New York: Plenum Press.CrossRefGoogle Scholar
Padua, R. A., Bulfield, G. & Peters, J. (1978). Biochemical genetics of a new glucose-phosphate isomerase allele (Gpi-1e) from wild mice. Biochemical Genetics 16, 127143.CrossRefGoogle ScholarPubMed
Roberts, R. C., Falconer, D. S., Bowman, P., & Gauld, I. K. (1976). Growth regulation in chimaeras between large and small mice. Nature (Lond) 260, 244245.CrossRefGoogle ScholarPubMed
Shaw, C. R. & Prasad, R. (1970). Starch gel electrophoresis of enzymes - A compilation of recipes. Biochemical Genetics, 4, 297320.CrossRefGoogle ScholarPubMed