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‘Midget’, a new dwarfing gene in the house mouse dependant on a genetic background of small body size for its expression

Published online by Cambridge University Press:  14 April 2009

Ruth E. Fowler  and
R. G. Edwards
Ruth E. Fowler
Affiliation:
Institute of Animal Genetics, West Mains Road, Edinburgh 9
R. G. Edwards
Affiliation:
Division of Experimental Biology, National Institute for Medical Research, Mill Hill, London, N.W.7
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Midget, a new dwarfing gene in the house mouse, was found in a line (NS) selected for small body size. Backcrosses to, and heterozygous matings of NS mice gave midget offspring in the expected 1:1 and 1:3 ratios. Backcrosses to two other lines of mice selected for small body size resulted in fewer midget offspring than expected and in a reduced phenotypic expression of the gene, though matings between these midget offspring gave all midget progeny.

A characteristic check in growth occurred between 15 and 21–24 days of age, and midgets rarely exceeded 10 g. at 6 weeks of age. They were 1·2 g. lighter than NS litter-mates at 3 weeks, and 3·6–4·4 g. lighter at 6 weeks. Fostering or transferring 3½-day-old midget embryos to the uteri of large mothers slightly increased the growth-rate, though the characteristic growth check still persisted. Transfer as embryos did not influence the midget phenotype.

Midget males were of near-normal fertility. The females were semi-sterile due to irregularity or absence of oestrous cycles, failure to ovulate, or the death of embryos before implantation. Each of these factors, which were also found in NS mice, could be remedied by the administration of exogenous hormones.

The genetic factors underlying the expression of midget are discussed, and the physiological traits associated with this and with other dwarfing genes are compared.

Type
Research Article
Information
Genetics Research , Volume 2 , Issue 2 , July 1961 , pp. 272 - 282
Copyright
Copyright © Cambridge University Press 1961

References

REFERENCES

Boettiger, E. & Osborn, C. M. (1938). A study of natural growth and ossification in hereditary dwarf mice. Endocrinology, 22, 447–457.Google Scholar
Elftman, H. & Wegelius, O. (1959). Anterior pituitary cytology of the dwarf mouse. Anat. Rec. 135, 43–47.CrossRefGoogle ScholarPubMed
Falconer, D. S. (1953). Selection for large and small size in mice. J. Genet. 51, 470–501.Google Scholar
Falconer, D. S. (1955). Patterns of response in selection experiment with mice. Cold Spr. Harb. Symp. quant. Biol. 20, 178–196.CrossRefGoogle ScholarPubMed
Falconer, D. S. (1960). Selection of mice for growth on high and low planes of nutrition. Genet. Res. 1, 91–113.CrossRefGoogle Scholar
Falconer, D. S. & Isaacson, J. H. (1959). Adipose, a new inherited obesity of the mouse. J. Hered. 50, 290–292.CrossRefGoogle Scholar
Francis, T. (1944). Studies in hereditary dwarfism in mice. Acta path. microbiol. scand. 21, 928–956.Google Scholar
Fowler, R. E. & Edwards, R. G. (1957). Induction of superovulation and pregnancy in mature mice by gonadotrophins. J. Endocrin. 15, 374–384.CrossRefGoogle ScholarPubMed
Fowler, R. E. & Edwards, R. G. (1960). The fertility of mice selected for large or small body size. Genet. Res. 1, 393–407.Google Scholar
King, J. W. B. (1950). Pygmy, a dwarfing gene in the house mouse. J. Hered. 41, 249–252.Google Scholar
King, J. W. B. (1955). Observations on the mutant ‘pygmy’ in the house mouse. J. Genet. 53, 487–497.Google Scholar
MacArthur, J. W. (1944 a). Genetics of body size and related characters. Amer. Nat. 78, 142–157.Google Scholar
MacArthur, J. W. (1944 b). Genetics of body size and related characters. Amer. Nat. 78, 224–237.Google Scholar
Runner, M. N. & Gates, A. (1954). Conception in prepuberal mice following artificially induced ovulation and mating. Nature, Lond., 174, 222.CrossRefGoogle ScholarPubMed
Smith, P. E. & MacDowell, E. C. (1930). An hereditary anterior pituitary deficiency in the mouse. Anat. Rec. 46, 249–258.CrossRefGoogle Scholar
Smith, P. E. & MacDowell, E. C. (1931). The differential effect of hereditary mouse dwarfism on the anterior pituitary hormone. Anat. Rec. 50, 85–93.Google Scholar
Smithberg, M. & Runner, M. N. (1956). The induction and maintenance of pregnancy in prepuberal mice. J. exp. Zool. 133, 441–457.Google Scholar
Smithberg, M. & Runner, M. N. (1957). Pregnancy induced in genetically sterile mice. J. Hered. 48, 97–100.CrossRefGoogle Scholar
Snell, G. D. (1929). Dwarf, a new mendelian recessive character of the house mouse. Proc. nat. Acad. Sci., Wash., 15, 733–734.Google Scholar