Margaret Kidwell

Regents Professor Emerita
no image
megkidwell@mac.com

Positions and Education: 

  • B. Sc., Nottingham University, UK. 1953
  • M.S., Iowa State University, 1962
  • Ph.D., Brown University, 1973
  • 1955-60 Officer in the National Agricultural Advisory Service, London, England
  • 1960-61 Kellogg Foundation Fellow, Iowa State University
  • 1966-70 Associate in Research, Brown University
  • 1971-72 Teaching Assistant, Brown University
  • 1973-74 Research Fellow, Brown University
  • 1974-75 Research Associate, Brown University
  • 1975-77 Investigator, Brown University
  • 1977-80 Assistant Professor (Research), Brown University
  • 1978 Visiting Scholar, Institute of Animal Genetics, Edinburgh
  • 1980-84 Associate Professor of Biology (Research), Brown University
  • 1981 Visiting Distinguished Lecturer at the University of Texas at Austin
  • 1984-85 Professor of Biology, Brown University
  • 1984 Visiting Scholar, Dept. of Genetics, Cambridge University, England and Dept. of Biochemistry, Imperial College, London
  • 1985-94 Professor of Ecology and Evolutionary Biology, University of Arizona
  • 1988-91 Chair, Interdisciplinary Program in Genetics, University of Arizona.
  • 1991-92 Sabbatical leave, University of Edinburgh, Scotland.
  • 1992-97 Head, Dept. of Ecology and Evolutionary Biology, University of Arizona.
  • 1994-01 Regents' Professor of Ecology and Evolutionary Biology, University of Arizona.

Honors and Awards: 

  • Belper Prize, Nottingham University, 1954
  • Kellogg Foundation Fellowship, Iowa State University, 1960-61
  • Elected Fellow, American Association for the Advancement of Science, 1992
  • Elected Fellow, American Academy of Arts and Sciences, 1993
  • Wilhelmina Key Invited Lecturer, American Genetic Association, 1993
  • Regents' Professor of Ecology and Evolutionary Biology, 1994
  • Elected Member, National Academy of Sciences, 1996

Editorial Work: 

  • American Naturalist
  • Journal of Heredity
  • Australian Journal of Biological Sciences
  • Journal of Medical Entomology
  • Bioessays
  • Biochemical Genetics
  • Biologie Cellulaire
  • Journal of Molecular Evolution
  • BioScience
  • Insect Molecular Biology
  • BioEssays
  • Molecular Biology and Evolution
  • Cancer Research
  • Molecular and General Genetics
  • Chromosoma
  • Molecular Insect Science
  • Evolution
  • Mutation Research
  • Gene
  • Nature
  • Genetica
  • Quarterly Review of Biology
  • Genes and Development
  • Parasitology Today
  • Genetics
  • Proc. Natl. Acad. Sci., USA
  • Genetical Research
  • Science
  • Genome
  • Theoretical and Applied Genetics
  • Heredity
  • Trends in Ecology and Evolution
  • Hereditas
  • Trends in Genetics
  • Journal of Experimental Zoology

Associate Editorship: Evolution (1988-91)

Selected Publications: 

  1. Kidwell, M. G., A. W. Nordskog & R. H. Forsythe  1964. Variation among commercial strains of chickens in loss of egg albumen quality. Poultry Sci. 43: 38-42.
  2. Kidwell, M. G., A. W. Nordskog & R. H. Forsythe 1964. On the problem of correcting albumen quality measures for egg weight. Poultry Sci. 43: 42-49.
  3. Kidwell, J. F. & M. M. Kidwell 1966. The effects of inbreeding on body weight and abdominal chaeta number in Drosophila melanogaster. Can. J. Genet. Cytol. 8: 207-215.
  4. Kidwell, J. F. & M. M. Kidwell 1968. Evidence against the mutagenic effects of vibration on Drosophila melanogaster. J. Hered. 59: 231-234.
  5. Kidwell, J. F., M. L. Tracey, P. Glaser & M. M. Kidwell 1971. A chromosomal analysis of X-ray induced genetic variance of wing length in D. melanogaster. Can. J. Genet. Cytol. 13: 600-606.
  6. Kidwell, M. G. 1972. Genetic change of recombination value in Drosophila melanogaster: I. Artificial selection for high and low recombination and some properties of recombination-modifying genes. Genetics 70: 419-432.
  7. Kidwell, M. G. 1972. Genetic change of recombination value in Drosophila melanogaster. II. Simulated natural selection. Genetics 70: 433-443.
  8. Kidwell, M. G., J. F. Kidwell & M. Nei 1973. A case of high rate of spontaneous mutation affecting viability in Drosophila melanogaster. Genetics 75: 133-153.
  9. Kidwell M. G. & J. F. Kidwell 1975. Cytoplasm- chromosome interactions in Drosophila melanogaster. Nature 253:755-756.
  10. Kidwell, M. G. &  J. F. Kidwell  1975. Spontaneous male recombination  and mutation in isogenic-derived chromosomes of Drosophila melanogaster. J. Hered. 66: 367-375.
  11. Clegg, M. T., J. F. Kidwell, M. G. Kidwell & N. J. Daniels  1976. Dynamics of correlated genetic systems.  I. Selection in the region of the Glued locus of D. melanogaster.  Genetics 83: 793-810.
  12. Kidwell, M. G. & J. F. Kidwell  1976. Selection for male recombination in Drosophila melanogaster. Genetics 84: 333-351.
  13. Kidwell, M. G., J. F. Kidwell, & P. T. Ives 1977. Spontaneous, non-reciprocal mutation and sterility in strain crosses of Drosophila melanogaster. Mutation Research 42: 89-98.
  14. Kidwell, M. G., J. F. Kidwell & J. A. Sved 1977. Hybrid dysgenesis in D. melanogaster: a syndrome of aberrant traits including mutation, sterility & male recombination. Genetics 36: 813-33.
  15. Kidwell, M. G. 1977. Reciprocal differences in female recombination associated with hybrid dysgenesis in Drosophila melanogaster. Genet. Res. 30: 77-88.
  16. Broadhead, R. S., J. F. Kidwell & M. G. Kidwell 1977. Variation of the recombination fraction in Drosophila melanogaster females.  J. Hered. 68: 323-326.
  17. Clegg, M. T., J. F. Kidwell & M. G. Kidwell 1978. Dynamics of correlated genetic systems.  III. Behavior of chromosomal segments under lethal selection. Genetica 48: 95-106.
  18. Sved, J. A., D. C. Murray, R. E. Schaefer & M. G. Kidwell  1978. Male recombination is not induced in Drosophila melanogaster by extracts of strains with male recombination potential. Nature 257: 457-458.
  19. Picard, G., J. C. Bregliano, A. Bucheton, J. M. Lavige, A. Pelisson & M. G. Kidwell 1978. Non-Mendelian female sterility and hybrid dysgenesis in Drosophila melanogaster. Genet. Res.  32: 275-287.
  20. Kidwell, M. G. 1978. Hybrid dysgenesis in Drosophila melanogaster: no suppresser-X effect on male recombination. J. Hered. 64: 417-419.
  21. Kidwell, M. G. 1979. Hybrid dysgenesis in Drosophila melanogaster: the relationship between the P-M and I-R interaction systems. Genet. Res. 33: 205-217.
  22. Kidwell  M. G. & J. F. Kidwell 1979.  Dynamics of natural selection on a lethal fourth chromosome in Drosophila.  J. Hered. 70: 123-126.
  23. Kidwell, M. G. & J. B. Novy 1979. Hybrid dysgenesis in Drosophila melanogaster: sterility resulting from gonadal dysgenesis in the P-M system. Genetics 92: 1127-1140.
  24. Schaefer, R. E., M. G. Kidwell & A. Fausto-Sterling 1979. Hybrid dysgenesis in Drosophila melanogaster: morphological and cytological studies of ovarian dysgenesis. Genetics 92: 1141-1152.
  25. Kidwell, M. G., J. B. Novy  &  S. M. Feeley 1981. Rapid unidirectional change of hybrid dysgenesis potential in Drosophila.  J. Hered. 72: 32-38.
  26. Kidwell, M. G. 1981. The use of pupation height as a method for distinguishing between the sibling species Drosophila melanogaster  and Drosophila simulans. Dros. Inf. Serv. 56: 81-82.
  27. Kidwell, M. G. 1981. Hybrid dysgenesis in Drosophila melanogaster: the genetics of cytotype determination in a neutral strain. Genetics 98: 275-290.
  28. Rubin, G. M., M. G. Kidwell & P. M. Bingham 1982. The molecular basis of P-M hybrid dysgenesis: The nature of induced mutations.  Cell 29: 987-994.
  29. Bingham, P. M., M. G. Kidwell & G. M. Rubin 1982. The molecular basis of P-M hybrid dysgenesis: The role of the P element, a P strain-specific transposon family. Cell 29: 995-1004.
  30. Bregliano, J. C. & M. G. Kidwell 1983. Hybrid dysgenesis determinants.  In: Mobile Genetic Elements  (ed. J. A. Shapiro) pp. 363-410. Academic Press, London, New York.
  31. Kidwell, M. G. 1983. Intraspecific hybrid sterility.  In: The Genetics and Biology of Drosophila, Vol. 3c. (Eds. M. Ashburner, H. Carson, & J. N. Thompson, Jr.) pp. 125-154. Academic Press, London.
  32. Kidwell, M. G. 1983. Evolution of hybrid dysgenesis determinants in Drosophila melanogaster. Proc. Nat. Acad. Sci. USA 80: 1655-1659.
  33. Kidwell, M. G. 1983. Hybrid dysgenesis in Drosophila melanogaster : factors affecting chromosomal contamination in the P-M system. Genetics 104: 317-341.
  34. Kidwell, M. G., T. Frydryk & J. B. Novy  1983. The hybrid dysgenesis potential of Drosophila melanogaster  strains of diverse temporal and geographic origin. Dros. Inf. Serv. 59: 63-69.
  35. Kidwell, M. G. 1984. Hybrid dysgenesis in Drosophila melanogaster : partial sterility associated with embryo lethality in the P-M system. Genet. Res. 44: 11-28.
  36. Kiyasu, P. K. &  M. G. Kidwell  1984. Hybrid dysgenesis in D. melanogaster: the evolution of mixed P and M populations maintained at high temperature. Genet. Res. 44: 251-259.
  37. Kidwell, M. G. 1984. Hybrid dysgenesis in Drosophila:  some implications for genetics evolution and recombinant DNA technology. Bull. Genet. Soc. Canada 15: 53-56.
  38. Kidwell, M. G. & J. B. Novy 1985. The distribution of hybrid dysgenesis determinants in North American populations of Drosophila melanogaster. Dros. Inf. Serv. 61: 97-100.
  39. Kidwell, M. G. 1985. Hybrid dysgenesis in Drosophila melanogaster :nature and inheritance of P element regulation. Genetics 111: 337-350. 
  40. Kidwell, M. G. 1986. Molecular and phenotypic aspects of the evolution of hybrid dysgenesis systems. In: Evolutionary Processes and Theory  (eds. S. Karlin & E. Nevo) Academic Press, New York, pp. 169-198.
  41. Kidwell, M. G. & H. M. Sang 1986. Hybrid dysgenesis in Drosophila melanogaster : synthesis of an RP strain by chromosomal contamination. Genet. Res. 47:181-185.
  42. Kidwell, M. G. 1986.  P-M mutagenesis.  In: Drosophila: A Practical Approach  (ed. D. B. Roberts) I.R.L. Press, Oxford, pp. 59-82.
  43. Daniels, S. B., S. H. Clark, M. G. Kidwell & A. Chovnick  1987. Genetic transformation of Drosophila melanogaster with an autonomous P  element: phenotypic and molecular analyses of long-established transformed lines.  Genetics 115: 711-723.
  44. Boussy, I. A. & M. G. Kidwell 1987. The P-M hybrid dysgenesis cline in eastern Australian Drosophila melanogaster: discrete P, Q and M regions are nearly contiguous. Genetics 115:737-745.
  45. Black, D. M., Jackson, M. S., Kidwell, M. G. & Dover, G. A. 1987. KP elements repress P-induced hybrid dysgenesis in D. melanogaster.  EMBO J. 5: 4125-4135.
  46. Kidwell, M. G. 1987. A survey of success rates with P element mutagenesis. Drosophila Inform. Serv. 66: 81-86.
  47. Daniels, S. B., I. A. Boussy, A. Tukey, M. Carrillo & M. G. Kidwell 1988. Variability among true M lines in P-M gonadal dysgenesis potential. Drosophila Inform. Serv. 66: 37-39.
  48. Kidwell, M. G. 1988. Regulation of expression of P-M hybrid dysgenesis in Drosophila. Banbury Report 30,  Cold Spring Harbor Laboratory, Cold Spring Harbor, NY. pp. 183-194.
  49. Boussy I. A., M. J. Healy, J. G. Oakeshott & M. G. Kidwell  1988. Molecular analysis of the P-M gonadal dysgenesis cline in Eastern Australian Drosophila melanogaster. Genetics 119: 889-902.
  50. Anxolabéhère, D., M. G. Kidwell & G. Periquet  1988. Molecular characteristics of diverse populations are consistent with the hypothesis of a recent invasion of Drosophila melanogaster  by mobile P elements.  Mol. Biol. Evol. 5: 252-269.
  51. Kidwell, M. G., K. Kimura & D. M. Black 1988. Evolution of hybrid dysgenesis potential in Drosophila melanogaster following P element contamination. Genetics 115: 819-828.
  52. Anxolabéhère, D., M. G. Kidwell & G. Periquet 1989. L'histoire d'une invasion génétique.  La Recherche 20: 1328-1338.
  53. Daniels, S. B., A. Chovnick & M. G. Kidwell 1989. Hybrid dysgenesis in Drosophila simulans lines transformed with autonomous P elements. Genetics 121: 281-291.
  54. Anxolabéhère, D., M. G. Kidwell & G. Periquet  1990.  Historia de una invacion genetica.  El Mundo Scientifico 98: 48-58.
  55. Kidwell, M. G. 1990. Evolutionary aspects of hybrid dysgenesis in Drosophila.  (Proc. of a Symposium on Hybridization and Introgression in Insects.  XVIII International Congress of Entomology.  Editors J. Spence & R. Gooding). Can. J. Zool. 68: 1716-1726.
  56. Kidwell, M. G., K. R. Peterson, S. B. Daniels 1990. Evolution of P elements in the genus Drosophila. pp. 107-116,  in: Molecular Evolution, UCLA Symposium on Molecular and Cellular Biology, New Series, Vol. 122. Eds M. Clegg & S. O'Brien. Alan R. Liss, Inc. New York, NY.
  57. Daniels, S. B.,  K. R. Peterson, L. D. Strausbaugh, M. G. Kidwell & A. Chovnick 1990. Evidence for horizontal transmission of the P transposable element between Drosophila species. Genetics 124: 339-355.
  58. Kidwell, M. G. & K. R. Peterson 1991. Evolution of transposable elements in Drosophila, pp. 139-154,  In: Proceedings of 1989 Wistar Symposium on New Perspectives in Evolution.  Editors L. Warren & M. Messelson. Alan R. Liss, Inc. New York, NY.
  59. Houck, M. A., J. B. Clark, K. R. Peterson & M. G. Kidwell  1991. Possible horizontal transfer of Drosophila genes by the mite Proctolaelaps regalis. Science 253: 1125-1129.
  60. de Frutos, R., K. R. Peterson & M. G. Kidwell. 1992. Distribution of Drosophila melanogaster  transposable element sequences in species of the obscura group. Chromosoma 101: 293-300.
  61. Kidwell, M. G. 1992. Horizontal transfer of the P element and other short inverted repeat transposons. Genetica 19: 913-916.
  62. Kidwell, M. G. & J. M. C. Ribeiro 1992. Can transposable elements be used to drive disease refractoriness genes into vector populations?  Parasitology Today 86: 275-286.
  63. Kidwell, M. G. 1992. Horizontal transfer. Curr. Opinion. Genet. Develop. 2: 868-873.
  64. Kidwell, M. G.. 1993. The voyage of an ancient mariner.  Nature 362:202.
  65. Kimura, K., Okumura T., Ninaki O., Kidwell, M. G. & Suzuki, K. 1993. Transposable elements in commercially useful insects: I. Southern hybridization study of silkworms and honeybees using Drosophila probes. Japan J. Genet. 68:63-71.
  66. Kidwell, M. G. 1993. Lateral transfer in natural populations of eukaryotes. Ann. Rev. Genet. 27: 235-256.
  67. Ribeiro, J. M. C. & M. G. Kidwell 1994. Transposable elements as population drive mechanisms: specification of critical parameter values.  J. Med. Entomology 31: 10-16.
  68. Clark, J. B., W. P. Maddison & M. G. Kidwell  1994. Phylogenetic analysis supports horizontal transfer of P transposable elements. Mol. Biol. Evol. 11:40-50.
  69. Kidwell, M. G. 1994. The evolutionary history of the P family of transposable elements. J. Heredity 85: 339-346.
  70. Kimura, K. & M. G. Kidwell  1994. Differences in P element population dynamics between the sibling species Drosophila melanogaster and Drosophila simulans. Genet. Res. 63: 27-38.
  71. Kim, W. & Kidwell, M. G. 1994.  In situ hybridization to polytene chromosomes using Digoxigenin-11-dUTP labeled probes. Drosophila Information Service 75:44-47.
  72. Kim, W., M. Wojciechowski, L. Bieling & M. G. Kidwell  1994. Genetic transformation with P transposable vectors carrying the rosy gene in D. melanogaster.  Drosophila Information Service 75:169-171
  73. Ribeiro, J. M. C. & M. G. Kidwell 1994. Response to letter to the Editor.  J. Med. Entomology 31: 10-16.
  74. Clark, J. B. & M. G. Kidwell  1995. Molecular biology and evolution of P transposable elements in Drosophila. Evolucion Biologica 8/9: 1-36.
  75. Clark, J. B., T. K. Altheide, M. J. Schlosser & M. G. Kidwell. 1995.  Molecular evolution of P transposable elements in the genus Drosophila.  I. The saltans and willistoni species groups.  Mol. Biol. Evol. 12:902-913.
  76. Prokchorova, A. V., C. M. A. Carareto, M. F. Wojciechowski and M. G. Kidwell. 1995.  A new autonomous P element vector with a multiple cloning site for insertion of a variety of DNA sequences. Drosophila Information Service 76:191-192.
  77. Kidwell, M. G. and D. Lisch. 1997.  Transposable elements as sources of variation in animals and plants. Proc. Natl. Acad. Sci.  94: 7704-7711.
  78. Clark, J. B. and M. G. Kidwell 1997. A phylogenetic perspective on P element evolution in Drosophila.  Proc. Natl. Acad. Sci. USA  94: 11428-11433.
  79. Clark, J. B. and M. G. Kidwell 1997. Evidence for horizontal transfer of the P transposable element between Drosophila species. Proc. Conf. on Horizontal Transfer, Fallen Leaf Lake, CA. Sept. 1997.
  80. Carareto, C. M. A., W. Kim, M. F. Wojciechowski, P. M. O'Grady,  A. V. Prokchorova, J. C. Silva and M. G. Kidwell.  1997. Testing transposable elements as genetic drive mechanisms using Drosophila P element constructs as a model system. Genetica 101: 13-34.
  81. O’Grady, P. M., J. B. Clark and M. G. Kidwell. 1998.  Phylogeny of the Drosophila saltans species group based on combined analysis of nuclear and mitochondrial DNA sequences.  Mol. Biol. and Evol. 15: 656-664.
  82. Clark, J. B., P. Kim and M. G. Kidwell. 1998.  Molecular evolution of P transposable elements in the genus Drosophila.  III. The melanogaster species group. Mol. Biol. Evol. 15: 746-755.
  83. Kidwell, M. G. and A. R. Wattam  1998. Commentary. An important step forward in the manipulation of mosquito disease vectors.  Proc. Natl. Acad. Sci. 95:3349-3450.
  84. Kidwell, M. G. and D. R. Lisch.  1998.  Transposons unbound. Nature 393: 22-23.    
  85. García-Plannells, J., Paricio, N., de Frutos, R., Clark, J. B., Kidwell, M. G.  1998. Molecular evolution of P transposable elements in the genus Drosophila.  II. The obscura species group. J. Mol. Evol. 47: 282-91.
  86. Lee, S. H., J. B. Clark, and M. G. Kidwell. 1999.  A P-homologous sequence in the house fly, Musca domestica.  Insect Molecular Biology 8:491-500.
  87. Zelentsova, H., H. Poluectova, L. Mnjoian, G. Lyozin, V. Veleikodvorskaja, L. Zhivotovski, M. G. Kidwell and M. B. Evgen'ev  1999.  Distribution and evolution of mobile elements in the virilis  species group of Drosophila.  Chromosoma 108: 443-456.
  88. Kidwell, M. G. and D. R. Lisch  2000. Transposable elements and host genome evolution. Trends Ecol. Evol. 15: 95-99.
  89. Kidwell, M. G. and D. R. Lisch  2000. Reply to Transposable elements and asexual reproduction Trends Ecol. Evol. 15: 288.
  90. Kidwell, M. G. and M. B. Evgen'ev.  2000. How valuable are model organisms for transposable element studies? Genetica 107:103-111
  91. Evgen'ev, M. B., H. Zelentsova, L. Mnjoian, H. Poluectova and M. G. Kidwell  2000. Invasion of Drosophila virilis  by the Penelope  transposable element. Chromosoma 109:350-357.
  92. Silva, J. C. and Kidwell, M. G. 2000.  Selection and horizontal transfer in the evolution of P elements. . Mol. Biol. Evol. 17:1542-1557
  93. Evgen'ev, M. B.,  Zelentsova, H., Poluectova, H.,  Lyozin, G. T., Veleikodvorskaja, V., Pyatkov, K. I., Zhivotovsky, L. A.  and Kidwell, M. G. 2000. Mobile elements and chromosomal evolution in the virilis group of Drosophila. Proc. Natl. Acad. Sci. USA 97:11337-11342..
  94. Kidwell, M. G. 2001. Hybrid dysgenesis determinants and other useful transposable elements in Drosophila.  Encyclopedia of Genetics. Ed. E. C. R. Reeve.  Dearborn Publishers, New York.
  95. Kidwell,  M. G. and D. R. Lisch  (2001)   Perspective: Transposable elements, parasitic DNA and genome evolution. Evolution 55.1-24..
  96. Kidwell, M. G. 2001. Horizontal transfer.  In: Encyclopedia of Genetics, Eds. Sydney Brenner and Jeffrey Miller. Academic Press, London..
  97. Kidwell, M. G. 2001. Hybrid dysgenesis In: Encyclopedia of Genetics, Eds. Sydney Brenner and Jeffrey Miller Academic Press, London..
  98. Lyozin, G. T., K. S. Makarova, V. V. Velikodvorskaja, H. S. Zelentsova, R. R. Khechumian, M. G. Kidwell, E. V. Koonin, and M. B. Evgen'ev. 2001. The structure and evolution of Penelope in the Drosophila virilis species group: an ancient lineage of retroelements. J. Mol. Evol. 52: 445-456.
  99. Loreto, E. L. da S., Valente, V. L. da S.,  A. Zaha , J. C. Silva,  and Kidwell,  M.G. 2001. Drosophila mediopunctata P transposable element: a new example of horizontal transfer (J. Heredity 95: 3721-381.
  100. Lezin, G. T., K. V. Makarova, V. V. Velikodvorskaia, E. S. Zelentsova, R. R. Kechumian, M. G. Kidwell, E. V. Kunin and M. B. Evgen'ev 2001. Structure and evolutionary role of the Penelope mobile element in Drosophila species of the virilis group. Mol Biol (Mosk) 35:805-815.
  101. Kidwell, M. G. and A. J. Holyoake 2001. Transposon-induced hotspots for genomic instability. Genome Res. 11: 1321-1322.
  102. Kidwell, M. G. and D. R. Lisch  2001. Transposable Elements as Sources of Genomic Variation.  In: Mobile DNA II.  American Society of Microbiology Press, pps 59-92.
  103. Clark, J. B, Silva, J. C. and M. G. Kidwell . 2002. Evidence for horizontal transfer of the P transposable element. In Horizontal transfer (2nd edition) M. Synanen and C. Kado eds. Academic Press, London.. .  
  104. O'Grady, P. M. and M. G. Kidwell  2002. Phylogeny of the subgenus Sophophora (Diptera: Drosophilidae) based on combined analysis of nuclear and mitochondrial sequences. Mol Phylogenet Evol. 22: 442-453.
  105. Kidwell, M. G. 2002. Book Review: Keeping pace with opportunistic DNA. Science 195: 2219-2220.
  106. Kidwell, M. G. 2002. Transposable elements and the evolution of genome size in eukaryotes. Genetica  115: 49-63.
  107. Holyoake, A. J. and M. G. Kidwell, 2003. Vege and Mar: two novel hAT MITE families from Drosophila willistoni. Mol. Biol. Evol..20: 163-167.