Genetics, Vol 138, 125-134, Copyright © 1994

INVESTIGATIONS

Differential Regulation of Target Genes by Different Alleles of the Segmentation Gene hunchback in Drosophila

M. Hulskamp, W. Lukowitz, A. Beermann, G. Glaser and D. Tautz
Institut fur Genetik und Mikrobiologie der Universitat Munchen, 80638 Munchen Present address: Department of Cellular and Developmental Biology, Harvard University, 16 Divinity Avenue, Cambridge, Massachusetts 02138.

hunchback (hb) is a key regulatory gene in the early segmentation gene hierarchy of Drosophila. It codes for a transcription factor of the Cys(2)-His(2) zinc finger type and shows two separate zinc finger domains in its coding region. hb forms a morphogenetic gradient in the middle of the embryo that is required for setting the spatial boundaries of several target genes. We have analyzed the molecular lesions found in the different hb alleles and have studied the differential effects of these alleles on a number of such target genes. We find that in mutants in which the HB protein lacks a functional second finger domain, the regulation of the target genes Kruppel (Kr) and knirps (kni) is differentially affected. While this domain is required for the correct regulation of Kr, it is not necessary for the repression of kni. Furthermore, mutations affecting this domain lead to a decreased protein stability. The integration of the expression pattern of target genes was found to be distorted in a second class of mutants between the two finger domains which lead to gain of function or neomorphic phenotypes. The effects of these mutations were studied in detail and it was found that they fall into two classes, the first one interfering with the function of the maternal hb product, the second leading to a delayed segmentation. The function of the latter class appears to be linked to the secondary expression of hb in the parasegment 4 (PS4) stripe at blastoderm stage.

This article has been cited by other articles:

				K. D. Tran and C. Q. Doe Pdm and Castor close successive temporal identity windows in the NB3-1 lineage Development, November 1, 2008; 135(21): 3491 - 3499. [Abstract] [Full Text] [PDF]

				H. Marques-Souza, M. Aranda, and D. Tautz Delimiting the conserved features of hunchback function for the trunk organization of insects Development, March 1, 2008; 135(5): 881 - 888. [Abstract] [Full Text] [PDF]

				D. Papatsenko and M. S. Levine Dual regulation by the Hunchback gradient in the Drosophila embryo PNAS, February 26, 2008; 105(8): 2901 - 2906. [Abstract] [Full Text] [PDF]

				J. Pinnell, P. S. Lindeman, S. Colavito, C. Lowe, and R. M. Savage The divergent roles of the segmentation gene hunchback Integr. Comp. Biol., August 1, 2006; 46(4): 519 - 532. [Abstract] [Full Text] [PDF]

				M. A. Pultz, L. Westendorf, S. D. Gale, K. Hawkins, J. Lynch, J. N. Pitt, N. L. Reeves, J. C. Y. Yao, S. Small, C. Desplan, et al. A major role for zygotic hunchback in patterning the Nasonia embryo Development, August 15, 2005; 132(16): 3705 - 3715. [Abstract] [Full Text] [PDF]

				T. Mito, I. Sarashina, H. Zhang, A. Iwahashi, H. Okamoto, K. Miyawaki, Y. Shinmyo, H. Ohuchi, and S. Noji Non-canonical functions of hunchback in segment patterning of the intermediate germ cricket Gryllus bimaculatus Development, May 1, 2005; 132(9): 2069 - 2079. [Abstract] [Full Text] [PDF]

				J. Jaeger, M. Blagov, D. Kosman, K. N. Kozlov, Manu, E. Myasnikova, S. Surkova, C. E. Vanario-Alonso, M. Samsonova, D. H. Sharp, et al. Dynamical Analysis of Regulatory Interactions in the Gap Gene System of Drosophila melanogaster Genetics, August 1, 2004; 167(4): 1721 - 1737. [Abstract] [Full Text] [PDF]

				P. Z. Liu and T. C. Kaufman hunchback is required for suppression of abdominal identity, and for proper germband growth and segmentation in the intermediate germband insect Oncopeltus fasciatus Development, April 1, 2004; 131(7): 1515 - 1527. [Abstract] [Full Text] [PDF]

				T. Novotny, R. Eiselt, and J. Urban Hunchback is required for the specification of the early sublineage of neuroblast 7-3 in the Drosophila central nervous system Development, March 4, 2003; 129(4): 1027 - 1036. [Abstract] [Full Text] [PDF]

				S. Kumar, K. Jayaraman, S. Panchanathan, R. Gurunathan, A. Marti-Subirana, and S. J. Newfeld BEST: A Novel Computational Approach for Comparing Gene Expression Patterns From Early Stages of Drosophila melanogaster Development Genetics, December 1, 2002; 162(4): 2037 - 2047. [Abstract] [Full Text] [PDF]

				N. H. Patel, D. C. Hayward, S. Lall, N. R. Pirkl, D. DiPietro, and E. E. Ball Grasshopper hunchback expression reveals conserved and novel aspects of axis formation and segmentation Development, September 15, 2001; 128(18): 3459 - 3472. [Abstract] [Full Text] [PDF]

				M. Stauber, H. Taubert, and U. Schmidt-Ott Function of bicoid and hunchback homologs in the basal cyclorrhaphan fly Megaselia (Phoridae) PNAS, September 19, 2000; (2000) 190095397. [Abstract] [Full Text]

				E. A. Wimmer, A. Carleton, P. Harjes, T. Turner, and C. Desplan bicoid-Independent Formation of Thoracic Segments in Drosophila Science, March 31, 2000; 287(5462): 2476 - 2479. [Abstract] [Full Text]

				J. Kehle, D. Beuchle, S. Treuheit, B. Christen, J. A. Kennison, M. Bienz, and J. Müller dMi-2, a Hunchback-Interacting Protein That Functions in Polycomb Repression Science, December 4, 1998; 282(5395): 1897 - 1900. [Abstract] [Full Text]

				X Wu, R Vakani, and S Small Two distinct mechanisms for differential positioning of gene expression borders involving the Drosophila gap protein giant Development, January 10, 1998; 125(19): 3765 - 3774. [Abstract] [PDF]

				D Kosman and S Small Concentration-dependent patterning by an ectopic expression domain of the Drosophila gap gene knirps Development, January 4, 1997; 124(7): 1343 - 1354. [Abstract] [PDF]

				M. Stauber, H. Taubert, and U. Schmidt-Ott Function of bicoid and hunchback homologs in the basal cyclorrhaphan fly Megaselia (Phoridae) PNAS, September 26, 2000; 97(20): 10844 - 10849. [Abstract] [Full Text] [PDF]