Summary
The embryonic organization of the sexually dimorphic genital disc was studied in genetic mosaics resulting (a) from early loss of a chromosome or (b) from mitotic recombination.
-
(a)
Early Loss of a Chromosome. Three types of mosaics were produced — purely female mosaics, purely male mosaics, and gynandromorphs. They show that the genital disc arises from a group of cells in the ventral region of the embryo somewhat larger than that giving rise to a single foreleg (Table 2). Within this group of cells three regions can be distinguished that are present in both sexes: an anterior, a medial, and a posterior one, with distances of only 3–4 sturts between adjacent regions. The anterior region gives rise to the female genitalia, the medial region to the male genitalia, and the posterior region forms the analia of both sexes and the parovaria of the female (Figs. 2 and 3). The relative positions of the three regions were deduced from sturt distances (Tables 1 and 5), and from frequencies of mosaicism (Table 2).
-
(b)
Mitotic recombination was induced at the blastoderm stage in order to produce twin spots in the external genitalia and analia of purely male and female flies. Clone sizes indicate that these structures arise from a small number of precursor cells (Table 4). Clones overlapped right and left sides, but no clones were found extending over analia and genitalia. However, within either the analia or the genitalia of each sex, no clonal restrictions could be observed, and the clones comprised structures that were up to 12 sturts apart. A comparison of clone sizes and sturt distances in the foreleg and in the genital disc indicates that equal gynandromorph distances involve equal numbers of cells in different regions on the ellipsoid egg (Fig. 5).
The results obtained from all mosaics provide a consistent picture of the embryonic organization of the genital disc. This becomes apparent in the summarized fate maps (Fig. 4), where the map derived from normal gynandromorphs can be produced by a simple superposition of the male and the female maps. The data are also discussed with respect to mechanisms of sexual differentiation in the genital disc.
Similar content being viewed by others
References
Baker, P.S.: Paternal loss (pal): a meiotic mutant inDrosophila melanogaster causing loss of paternal chromosomes. Genetics80, 267–296 (1975)
Bodenstein, D.: The postembryonic development ofDrosophila. In: Biology of Drosophila (M. Demerec, ed.), pp. 275–367 New York: Wiley, N. Y. 1965
Bryant, P.J., Hsei, B.W.: Pattern formation in asymmetrical and symmetrical imaginal discs ofDrosophila melanogaster. Am. Zool.17, 595–612 (1977)
Bryant, P.J., Schneiderman, H.A.: Cell lineage, growth and determination in the imaginal leg disc ofDrosophila melanogaster. Develop. Biol.20, 263–290 (1969)
Dübendorfer, A.: Untersuchungen zum Anlageplan und Determinationszustand der weiblichen Genital- und Analprimordien vonMusca domestica. Wilhelm Roux's Archiv168, 142–168 (1971)
Dübendorfer, K.: Die Entwicklung der männlichen und weiblichen Genital-Imaginalscheibe vonDrosophila melanogaster: Eine klonale Analyse. Ph. D. Thesis, Zoological Institute, University of Zurich, Switzerland (1977)
Emmert, W.: Entwicklungsleistungen abdominaler Imaginalscheiben vonCalliphora erythrocephala. Experimentelle Untersuchungen zur Morphologie des Abdomens. Wilhelm Roux's Archiv169, 87–133 (1972)
Garcia-Bellido, A.: Some parameters of mitotic recombination inDrosophila melanogaster. Molec. Gen. Genetics.115, 54–72 (1972)
Gehring, W., Wieschaus, E., Holliger, M.: The use of “normal” and “transformed” gynandromorphs in mapping the primordial germ cells and the gonadal mesoderm inDrosophila. J. Embryol. Exp. Morphol.35, 607–616 (1976)
Gleichauf, R.: Anatomie und Variabilität des Geschlechtsapparates vonDrosophila melanogaster Meig. Z. wiss. Zool.148, 1–66 (1936)
Haynie, J.L., Bryant, P.J.: The effects of X-rays on the proliferation dynamics of cells in the imaginal wing disc ofDrosophila melanogaster. Wilhelm Roux's Archives183, 85–100 (1977)
Hotta, Y., Benzer, S.: Mapping of behavior inDrosophila mosaics. In: Genetic Mechanisms of Development (F. Ruddle, ed.), New York: Academic Press 1973
Janning, W.: Aldehydeoxidase as a cell marker for internal organs inDrosophila melanogaster. Naturwiss.59, 516–617 (1972)
Janning, W.: Entwicklungsgenetische Untersuchungen an Gynandern vonDrosophila melanogaster. II. Der morphogenetische Anlageplan. Wilhelm Roux's Archiv174, 349–359 (1974)
Janning, W.: Entwicklungsgenetische Untersuchungen an Gynandern vonDrosophila melanogaster. IV. Vergleich der morphogenetischen Anlagepläne larvaler und imaginaler Strukturen. Wilhelm Roux's Archiv179, 349–372 (1976)
Laugé, G.: Recherches expérimentales sur la détermination et la différenciation des caractères morphologiques et histologiques des intersexués triploides deDrosophila melanogaster Meig. Ann. Embryol. Morph.2, 245–270 (1969)
Lawrence, P.A., Morata, G.: The early development of mesothoracic compartments inDrosophila. An analysis of cell lineage and fate mapping and an assessment of methods. Develop. Biol.56, 40–51 (1977)
Lindsley, D.L., Grell, E.H.: Genetic variations ofDrosophila melanogaster. Carnegie Inst. Washington Publ.627 (1968)
Madhavan, M.M., Schneiderman, H.A.: Histological analysis of the dynamics of growth of imaginal discs and histoblast nests during the larval development ofDrosophila melanogaster. Wilhelm Roux's Archives183, 269–305 (1977)
Muraglia, M.: Analyse der Blastoderm Primordien der männlichen Genitalscheibe beiDrosophila melanogaster. M.A. Thesis, Zoological Institute, University of Zurich, Switzerland (1977)
Nissani, M.: Cell lineage analysis of germ cells ofDrosophila melanogaster. Nature265, 729–731 (1977)
Nöthiger, R., Dübendorfer, A., Epper, R.: Gynandromorphs reveal two separate primordia for male and female genitalia inDrosophila melanogaster. Wilhelm Roux's Archives181, 367–373 (1977)
Schüpbach, T.: The embryonic organization of the female genital disc and the origin and development of the female germline studied in mosaics ofDrosophila melanogaster. Ph. D. Thesis, Zoological Institute, University of Zurich, Switzerland (1978)
Schüpbach, T., Wieschaus, E., Nöthiger, R.: A study of the female germline in mosaics ofDrosophila. Wilhelm Roux's Archives184, 41–56 (1978)
Seidel, S.: Experimentelle Untersuchungen über die Grundlagen der Sterilität von Transformer (tra) Männchen beiDrosophila melanogaster. Z.f. Vererbungslehre94, 215–241 (1963)
Steiner, E.: Establishment of compartments in the developing leg imaginal discs ofDrosophila melanogaster. Wilhelm Roux's Archives180, 9–30 (1976)
Sturtevant, A.H.: A gene inDrosophila melanogaster that transforms females into males. Genetics30, 297–299 (1945)
Ulrich, E.: Cell lineage, Determination und Regulation in der weiblichen Genitalimaginalscheibe vonDrosophila melanogaster. Wilhelm Roux's Archiv167, 64–82 (1971)
Wieschaus, E.: Cell lineage relationships in the earlyDrosophila embryo. In: Results and Problems in Cell Differentiation: Genetic Mosaics and Cell Differentiation (W. Gehring, ed.), Berlin-Heidelberg-New York: Springer 1978
Wieschaus, E., Gehring, W.: Clonal analysis of primordial disc cells in the early embryo ofDrosophila melanogaster. Develop. Biol.50, 249–263 (1976a)
Wieschaus, E., Gehring, W.: Gynandromorph analysis of the thoracic disc primordia inDrosophila melanogaster. Wilhelm Roux's Archives180, 31–46 (1976b)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Schüpbach, T., Wieschaus, E. & Nöthiger, R. The embryonic organization of the genital disc studied in genetic mosaics ofDrosophila melanogaster . Wilhelm Roux' Archiv 185, 249–270 (1978). https://doi.org/10.1007/BF00848355
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00848355