Title: Analysis of development
Identifier: analysisofdevelo00will (find matches)
Year: 1955 (1950s)
Authors: Willier, Benjamin H. (Benjamin Harrison), b. 1890
Subjects: Embryology; Embryology
Publisher: Philadelphia, Saunders
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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A B C Fig. 44. First tarsal joint of Drosophila melano- gaster. A, Normal male; distal (upper right) sex- comb consisting of a row of ten teeth. B, Gynander; sex-comb consisting of four teeth, interrupted by a bristle of female genotype. C, Gynander; sex-comb consisting of two teeth located in a region normally not occupied by sex-comb structures. (After Stern and Hannah, '50.) extent may originate in the appropriate re- gions of otherwise genetically female tissues (Stern and Hannah, '50). The observations indicate that male and female genotypes alike lead to the emergence of a sex-comb field but that the response of the cells in the region of the prospective cells depends on their own genotype, male cells forming teeth of the sex-comb even if surrounded by fe- male tissvie and female cells being unable to form teeth even if in the appropriate region of a preponderantly male disc (Fig. 445, C). In a secondary fashion, however, the dif- ferent genotypes affect the field itself. When the cells of the typical sex-comb region are female in constitution and therefore unable to form a sex-comb, cells of male constitu- tion near by may differentiate into teeth of a sex-comb even though they are in a region which normally lies outside of the sex-comb region. It seems that the development of the sex-comb in the typical region modifies the surroundings so that no differentiation into further teeth occurs. Absence of tooth forma- tion in the typical region results in a modi- fication of the extent or intensity of the out- lying regions of the field such that male cells can respond to it which would not have done otherwise. This analysis of the origin of the sex-comb may serve as an illustration for many other cases where specific genotypes change the course of development both by varying the response of localized regions and by remolding more general developmental configurations. REFERENCES Balkaschina, E. I. 1929 Ein Fall der Erbhomoosis (die Genovariation "Aristopedia") bei Drosophila melanogaster. Roux' Arch. Entw.-mech., il5: 448-463. Bateson, W. 1894 Materials for the Study of Evolution. The Macmillan Co., London. Beadle, G. W. 1937 Development of eye colors in Drosophila: fat bodies and malpighian tubes in relation to diffusible substances. Genetics, 22: 587-611. ■ 1945 Biochemical genetics. Chem. Rev., 37.-15-96. , Tatum, E. L., and Clancy, C. W. 1939 Development of eye colors in Drosophila: pro- duction of V^ hormone by fat bodies. Biol. Bull., 75.-407-414. Bhat, M. R. 1949 A dominant mutant mosaic house mouse. Heredity, 3.-243-248. Bonner, David M. 1948 Genes as determiners of cellular biochemistry. Science, 108:73S-7?>9. Bonnevie, K. 1934 Embryological analysis of gene manifestation in Little and Bagg's abnormal mouse tribe. ,J. Exp. Zool., <^7.-443-520. Boveri, Th. 1902 trber mehrpolige Mitosen als Mittel zur Analyse des Zellkerns. Verb. phys. med. Ges. Wiirzburg, N. F. 35.67-90. 1907 Zellenstudien. VL Die Entwicklung dispermer Seeigeleier. Ein Beitrag zur Befruch- tungslehre und zur Theorie des Kernes. G. Fischer, Jena. Boycott, A. E., Diver, C, Garstang, S. L., and Turner, F. M. 1930 The inheritance of sin- istrality in Limnaea peregra (Mollusca, Pul- monata). Trans. Roy. Soc. London Phil., B219: 51-131. Brehme, K. 1941 Development of the Minute phenotype in Drosophila melanogaster: a com- parative study of the growth of three Minute mu- tations. J. Exp. Zool., 55.-135-160. Breitenbecher. J. K. 1925 The inheritance of sex- limited bilateral asymmetry in Bruchus. Genetics, /0.-261-277. Bridges. C. B. 1922 The origin of variations in sexual and sex-limited characters. Amer. Nat., 5^.51-63. -, and Brehme, K. 1944 The mutants of Drosophila melanogaster. Carnegie Inst. Wash- ington Publ. No. 522.

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