Broad range interests in the Wakimoto laboratory center around chromosome organization and its relationship to gene expression and chromosome maintenance. Two different projects are being pursued to address these issues. The first involves studies of the heterochromatin of Drosophila. Heterochromatin is generally regarded as transcriptionally silent and capable of inducing gene repression. However, several genes are located within the heterochromatin and when these genes are displaced from heterochromatin by chromosome rearrangements, they show abnormal expression. In order to understand this phenomenon known as position effect variegation, and the function of heterochromatin in general, Dr. Wakimoto's group is combining genetic, cytogenetic, and molecular tools to understand the structure and regulatory requirements of heterochromatic genes.
A second major research goal is to understand the regulation of events from chromosome condensation during spermiogenesis through sperm decondensation that occurs in the egg cytoplasm. This chain of events occurs in nearly all animal species and results in a dramatic change in chromatin packaging of an entire nucleus. Several paternal effect mutations of Drosophila have been identified that promise to provide insight into the molecules involved in this process. These mutations are being studied genetically and molecularly with the goal of identifying components that normally act to ensure sperm decondensation, the formation of the male pronucleus and stable maintenance of the paternal chromosomes during embryogenesis.
Wakimoto BT. (2000) Doubling the rewards: testis ESTs for Drosophila gene discovery and spermatogenesis expression profile analysis. Genome Res. 10(12), 1841-2.
Tomkiel, J.E., Wakimoto, B.T., and Briscoe, A. (2001) The teflon gene defines a function required for cohesion between autosomal homologs at meiosis I in Drosophila melanogaster. Genetics 157, 273-281.
Weiler, K.S. and Wakimoto, B.T. (2002) Suppression of heterochromatic gene variegation can be used to distinguish and characterize E(var) genes potentially important for chromosome structure in Drosophila melanogaster. Mol Genet Genomics 266(6):922-32.
Hoskins, R.A., Smith, C.D., Carlson, J.W., Carvalho, A.B., Halpern, A., Kaminker, J.S., Kennedy, C., Mungall, C.J., Sullivan, B.A., Sutton, G.G., Yasuhara, J.C., Wakimoto, B.T., Myers, E.W., Celniker , S.E., Rubin, G.M., and Karpen, G.H. Heterochromatic sequences in a Drosophila whole-genome shotgun assembly. (2002) Genome Biol. 3(12):RESEARCH 0085.1-0085.16.
Pimpinelli, S. and Wakimoto, B.T. (2003) Expanding the boundaries of heterochromatin. Genetica 117 (1-2):111-116.
Yasuhara, J.C., Marchetti, M., Fanti, L., Pimpinelli, S., and Wakimoto, B.T. (2003) A strategy for mapping the heterochromatin of Chromosome 2 of Drosophila melanogaster. Genetica 117(1-2): 217-226.
Giansanti, M.G., Farkas, R.M., Bonaccoris, S., Lindsley, D.L., Wakimoto, B.T., Fuller, M.T., and Gatti, M. (2004) Genetic dissection of meiotic cytokinesis in Drosophila males. Molecular Biology of the Cell 15: 2509-2522.
Wakimoto, B.T., Lindsley, D.L., Herrera, C. (2004) Toward a comprehensive genetic analysis of male fertility in Drosophila melanogaster. Genetics 167(1):207-16.
Yasuhara, J.C., DeCrease, C.H. and Wakimoto, B.T. (2005) Evolution of heterochromatic genes of Drosophila. Proc Natl Acad Sci U S A. 102(31):10958-63.