Prof. Daniel Segal
Ph.D.: 1981, Hebrew University
Phone: (Office) +972-3-640-9835
(Fax) +972-3-640-9407
E-mail: dsegal@post.tau.ac.il
Room#: Green 207
Member's portrait
  Personal Information
  Research Interests
  Selected Publications

Personal Information

Education

1970-73 B.Sc. Hebrew University, Biology
1974-75/
1977-81
Ph.D. Hebrew University, Genetics
1-9/1976 Univ. Utrecht, Developmental Biology


Academic Positions

1974-1981 Teaching Assistant, Department of Genetics, Hebrew University
4-10/1981 Post doc, Leiden University, Drosophila development
1981-1984 Post doc, Harvard University, Drosophila, developmental genetics
1984-1987 Scientist, Weizmann Institute of Science, Drosophila oncogene homologs, Drosophila neurogenetics
1987-1992 Lecturer, Tel-Aviv University, Drosophila, developmental genetics, Drosophila neuroendocrinology
1992-1996 Senior lecturer, Tel-Aviv University, Drosophila, developmental genetics, Drosophila neuroendocrinology
1993-1994 Visiting Professor, Indiana University, Molecular genetics of cultured cells
1996-1999 Head of the Department, Tel-Aviv University
1997-2008 Associate Professor, Department of Molecular Microbiology and Biotechnology, Tel-Aviv University
2008-ongoing Professor, Department of Molecular Microbiology and Biotechnology, Tel-Aviv University

Research Interests

Molecular genetics of the regulation of insect reproduction:

  1. The neuroendocrine regulation of insect reproduction is one of the most promising targets for intervention for purposes of pest control. Juvenile hormone (JH) a key component of this regulation. We use Drosophilaas a model to study the molecular details of the JH control of reproduction. We have demonstrated that JH production is reduced in Apterousmutants, and that they are defective in reproductive behavior. We have shown that the Apterousgene encodes LIM-containing transcription factor and are currently identifying genes interacting with it. We have started to similarly study the JH system in the Mediterranean fruit-fly which is a major pest worldwide, and are studying its Apteroushomolog.

  2. Courtship in insects is a highly stereotyped and genetically regulated behavior. We have identified Drosophilamutants defective in the early steps of male courtship and are studying them at the molecular, genetic and behavioral levels. We found that one of them encodes a ubiquitin-conjugating enzyme and are studying its role in the nervous system.
LIM-containing oncogene homolog in Drosophila
Apterouscontains LIM domains which like zinc-finger have been implicated in regulation of gene expression. We have isolated additional novel LIM genes from Drosophila. One of them is highly homologous to the human rhombotin oncogene which is involved in T-cell lymphoblastic leukemia. We have shown that the Drosophilahomolog corresponds to the Bx/hdpcomplex which controls wing development, and have generated novel insertional mutants in it. We are currently studying the gene and have identified novel and previously known genes that interact with it. We plan to examine this interaction at the molecular level focusing on the role of the LIM domain.

Genetic improvement of insect-killing nematodes for biological pest control
Biological control agents are safe measures for pest control to replace the traditional chemical pesticides which are hazardous to health and the environment. Insect-killing nematodes are the second-best bio-insecticides and their use increases steadily world wide. We apply genetic approaches for improving beneficial traits in these nematodes with the goal of enhancing their efficacy, thereby increasing their use. For example, we have used selection, mutagenesis, and cross-hybridization to generate nematode strains that are more resilient to environmental extremes such as heat, desiccation, and various pesticides. We have shown that the new strains retain these improved traits upon storage and do not lose other parameters of efficacy. Recently we began to use molecular techniques to clone genes related beneficial traits of these nematodes. Understanding the molecular basis of these traits will help to generate improved natural and transgenic nematode strains. Our approach should allow to expand the use of these nematodes to new agricultural niches such as arid and warm environments.

Selected Publications


Publications in refereed journals

R. D. St. Johnston, F. M. Hoffmann, R. K. Blackman, D. Segal, R. Grimaila, R. W. Padgett, H. A. Irick and W. M. Gelbart (1990). Molecular organization of the decapentaplegicgene in Drosophila melanogaster.Genes and Develop. 4 : 1114-1127.

I. Glazer, R. Gaugler and D. Segal (1991). Genetics of the entomoparasitic nematode Heterorhabditis bacteriophora strain HP88 : Characterization of the diversity of beneficial traits in a wild type population. J. Nematology 23 : 324-333.

M. Altaratz, S. W. Applebaum, D.S. Richard, L. I. Gilbert, and D. Segal (1991). Regulation of juvenile hormone synthesis in wild-type and apterousmutant Drosophila. Molec. Cell. Endocrinol. 81 : 205-216. medline

J. Ringo, R. Werczberger, M. Altaratz and D. Segal (1991). Female sexual receptivity is defective in juvenile hormone-deficient mutants of the apterousgene of Drosophila melanogaster. Behav. Genet. 21: 453-470. medline

B. Cohen, E. McGuffin, C. Pfeifle, D. Segal and S. M. Cohen (1992). apterous:a gene required for imaginal disc development in Drosophila encodes a member of the LIM family of developmental regulatory proteins. Genes and Develop. 6: 715-729. medline

J. Ringo, R. Werczberger and D. Segal (1992). Male sexual signalling is defective in mutants of the apterousgene of Drosophila melanogaster. Behav. Genet. 22: 469-487. medline

S. Zioni (Cohen-Nissan), I. Glazer and D. Segal (1992). Life cycle and reproductive potential of Heterorhabditis bacteriphoraStrain HP 88. J. Nematology 24: 352-358.

S. Zioni (Cohen-Nissan), I. Glazer and D. Segal (1992). Phenotypic and genetic analysis of a mutant of Heterorhabditis bacteriphora Strain HP 88. J. Nematology 24: 359-364.

D. Segal (1993). Prospects of using Drosophila for insect neuroendocrine research. Arch. Insect Biochem. Physiol. 22: 199- 231. medline

H. Koltai, I. Glazer, and D. Segal (1994). Phenotypic and genetic analysis of two new mutants of Heterorhabditis bacteriphora.J. Nematology 26: 32-32.

H. Koltai, I. Glazer, and D. Segal (1995). Reproduction of the entomopathogenic nematode Heterorhabditis bacteriphoraPoinar 1976: hermaphroditism vs. amphimixis. Fund. Appl. Nematology 18: 55-61.

H. Koltai, I. Glazer, and D. Segal (1995). Reproduction of the entomopathogenic nematode Heterorhabditis bacteriphoraPoinar 1976: hermaphroditism vs. amphimixis. Fund. Appl. Nematology 18: 55-61.

A. Shtorch , R. Werczberger, and D. Segal (1995). Molecular genetic studies on apterous a gene implicated in the juvenile hormone system in Drosophila.Arch. Insect Biochem. Physiol. 30: 195-209. medline

D. Shapiro, I. Glazer, and D. Segal (1996). Trait stability and fitness of the heat tolerant entomopathogenic nematode Heterorhabditis bacteriophoraIS5 strain. Biol. Control 6: 238-244. medline

D. Segal, L. Cherbas , and P. Cherbas (1996). Transformation of Drosophilacells in culture by P element-mediated transposition. Somatic Cell and Molecular Genetics 22: 159-165. medline

D. Shapiro, I. Glazer, and D. Segal (1997). Genetic improvement of heat tolerance in Heterorhabditis bacteriophora.through hybridization. Biol. Control 8: 153-159.

I. Glazer, L. Salame, and D. Segal (1997). Genetic enhancement of nematicide resistance in entomopathogenic nematodes. Biocont. Sci. Tecnnol. 7:499-512.

S. Orgad, S. G. Rosenfeld, Smolikove, T. Polak, and, D. Segal. (1997) Bhavioral analysis of Drosophilamutants displaying abnormal male courtship. Invertebr. Neurosci. 3: 175-183. medline

S. Orgad, H. Nelson, D. Segal, and N. Nelson (1998). Metal ions can suppress the abnormal taste behavior of the Drosophilamutant malvolio.J. Exp. Biol. 201: 115-120. medline

M. Shoresh, S. Orgad, O. Shmueli, R. Werczberger, D. Gelbaum, S. Abiri, and D. Segal (1998). Overexpression Beadex mutations and loss-of-function heldup-amutations in Drosophila affect the 3' regulatory and coding components, respectively of the Dlmogene. Genetics 150: 283-299. medline

D. Segal and I. Glazer (1999). Genetic approaches for enhancing beneficial traits in entomopathogenic nematodes. Jap. J. Nematol. 28: 101-107.

S. Freilich, Y. Kapp, Y. Nevo-Caspi, E. Oron, S. Orgad, D. Segal and D. A. Chamovitz (1999) The COP9 signalosome is essential for development of Drosophila melanogaster.Curr. Biol. 9:1187-1190. medline

X-W. Deng, W. Dubiel, N. Wei, K. Hofmann, K. Mundt, J. Colicelli, J-y. Kato, M. Naumann, D. Segal, M. Seeger, M. Glickman, and D.A. Chamovitz. (2000). Unified nomenclature for the COP9 signalosome and its subunits: an essential regulator of development. Trend. Genet. 16:202-203. medline

S. Orgad, G. Rosenfeld, R. Greenspan, and D. Segal. (2000). Courtless, the DrosophilaUBC7 homolog, is involved in male courtship behavior and spermatogenesis. Genetics 155: 1267-1280. medline

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