148 TEMPERATURE INDUCED HETEROPLOIDY 



Fankhauser and his students have analyzed the nucleoli, nuclei, cells, and organs of the 

 heteroploids. They find that when there are extra sets of nucleoli and of chromosomes, 

 that the increase in nuclear and cell size is compensated for by a corresponding decrease 

 in cell number. This decrease must occur early, for in the later stages of development 

 the mitotic rate of diploids and triploids seems to be much the same. There are corre- 

 sponding differences in organ size except for the gonads and the notochord. Further "The 

 diameter of the wall of the pronephric tubules and pronephric ducts, and the thickness of 

 the epithelium of the lens of the eye thus remain about the same from the haploid to the 

 pentaploid levels. " and "These observations show that in the amphibian embryo both cell 

 number and cell shape may be modified to allow the formation of organs of normal size 

 and structure. This indicates that both are subject to some control by the developing or- 

 ganism. " (Fankhauser, 1945). There is evidence that triploidy affects the females only, 

 the triploid larvae being undifferentiated or males. 



This field of investigation is extremely important from the physiological, morphological, 

 and genetical points of view. 



REFERENCES 



BARBER, H. N. & H. G. COLLAN, 1943 - "The effects of cold and colchicine on mitosis in the newt." Proc. Roy. Soc. London 



B. 131:258. 

 BEAL, J. M. , 1942 - "Induced chromosomal changes and their significance in growth and development. " Am. Nat. 76:239. 

 BEETSCHEN, Jean-Claude, I960 - "Recherches sur I'heteroploidie experimentelle chez un amphibien urodele Pleurodeles waltii." 



Michoh., Bull. Biol. 93:1-127. 

 BOOK, J. A. , 1940 - "Induction of haploidy in a cold treatment experiment with egg cells of the salamander Triton taeniatus. " 



Kungl. Fysiogr. Sallsk. Lund. Forh. 11, #12:1 (See also 1940 Hereditas 26:107). 

 BRICGS, R. W. , 1947 - "The experimental production and development of triploid frog embryos. " Jour. Exp. Zool. 106. 

 COSTELLO, D. P., 1942 - "Induced haploidy and triploidy in the California Triturus. " Anat. Rec. 84: suppl. 60. 

 DALCQ, A. , 1932 - "Contribution a I'analyse des fonctions nucleaires dans I'ontogenese de la grenouille. IV. Modifications de 



la formule chromosomiale. " Arr.h. Biol. 43:343. 

 DERMEN, H., 1938 - "A cytological analysis of polyploidy." Jour. Heredity. 29:211. 



FANKHAUSER, G. , 1937 - "The production and development of haploid salamander larvae. " Jour. Heredity. 28:3. 

 FANKHAUSER, G. , 1945 - "Maintenance of normal structure in heteroploid salamander larvae through compensation of changes 



in cell size by adjustment of cell number and cell shape. " Jour. Exp. Zool. 100:445. 

 FANKHAUSER, G., 1945 - "The effects of changes in chromosome number on amphibian development. " Quart. Rev. Biol. 



20:20. 

 FANKHAUSER, G. G R. R. HUMPHREY, 1943 - "The relation between the number of nucleoli and number of chromosome sets 



in animal cells. " Proc. Nat. Acad. Sci. 29:344. 

 FANKHAUSER, G. G R. WATSON, 1942 - "Heat-induced triploidy in the newt, Triturus viridescens. " Proc. Nat. Acad. Sci. 



28:436. 

 GALLIEN, L. P. , 1959 - "Recherches sur quelques aspects de I'heteroploidie experimentale chez le Triton pleurodeles waltii." 



Jour. Emb. Exp. Morph. 7:380-393. 

 GRIFFITHS, R. B. , 1941 - "Triploidy (and haploidy) in the newt, Triturus viridescens, induced by refrigeration of fertilized eggs. " 



Genetics. 26:69. 

 HEILBORN, O. , 1934 - "On the origin and preservation of polyploidy." Hereditas. 19:233. 

 HERTWIG, G. G P. HERTWIG, 1920 - "Triploide Froschlarven. " Arch. mikr. Anat. 94:34. 

 HUMPHREY, R. R. G G. FANKHAUSER, 1946 - "Tetraploid offspring of triploid axolotl females from matings with diploid 



males." Anat. Rec. 94:suppl. 95. 

 HUSKINS, C. L., 1941 - "Polyploidy and mutations. " Am. Nat. 75:329. 



KAYLOR, C. T. , 1940 - "Studies on experimental haploidy in salamander larvae. I. Experiments with eggs of the newt. Tri- 

 turus pyrrhogaster. " Biol. Bull. 79:397. 

 PARMENTER, C. L. , 1933 - "Haploid, diploid, and tetraploid chromosome numbers and their origin in parthenogenetically 



developed larvae and frogs of Rana pipiens and Rana palustris. " Jour. Exp. Zool. 66:409. 

 ROSTAND, J., 1936 - "Gynogenese par refroidlssement des oeufs chei Hyla arborea. " Comp. rendu. Soc. Biol. 122:1012. 

 VANDEL, A., 1937 - "Chromosome number, polyploidy and sex in the animal kingdom. " Ptoc. Zool. Soc. London. 107A:519. 



