The Myxobacteria are a group of Gram-negative bacteria that undergo a true multicellular development and a primitive differentiation. They provide a simple system from investigating the regulation of development because they resemble more familiar bacteria in structure and in their accessibility to genetic manipulation through mutation and gene cloning. Myxobacteria grow vegetatively like other bacteria, but when nutrients become limiting, Myxobacteria aggregate to form multicellular fruiting bodies. Within nascent fruiting bodies cells sporulate, changing - in the case of Myxococcus xanthus - from long rods to spherical spores, which are dormant. Under appropriate conditions, the spores germinate to give rod-shaped growing cells. Interactions between mycobacterial cells coordinate their development of fruiting bodies. The objective of the research proposed is to find out, in molecular and cellular terms, how cell-cell interactions coordinate this relatively simple developmental process. The signal molecules that cells use when they interact with each other in the formation of fruiting bodies will be isolated and identified. For this purpose, a set of mutants that are defective in producing individual signals will be used as bioassay cells. Receptors for athe signal molecules, and the signal transduction system will be studied using these mutants and a transposable probe for promoter activity. In the long term, this research may facilitate the understanding of human developmental birth defects and speed their medical treatment. Cell-cell interactions are known to be important in human embryonic development as well as in the normal function of the adult human immune system , but developmental interactions in embryos and the immune system of adults are difficult to investigate both technically and ethically. In Myxobacteria the full power of biochemistry and molecular genetics can be used to study its cell interactions. The experimental results may provide a point of departure for investigations in more complex organisms.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37GM023441-22
Application #
2634617
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1977-01-01
Project End
1999-12-31
Budget Start
1998-01-01
Budget End
1998-12-31
Support Year
22
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Stanford University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
Kaiser, Dale; Warrick, Hans (2014) Transmission of a signal that synchronizes cell movements in swarms of Myxococcus xanthus. Proc Natl Acad Sci U S A 111:13105-10
Kaiser, Dale (2007) Bacterial swarming: a re-examination of cell-movement patterns. Curr Biol 17:R561-70
Wu, Yilin; Jiang, Yi; Kaiser, Dale et al. (2007) Social interactions in myxobacterial swarming. PLoS Comput Biol 3:e253
Yu, Rosa; Kaiser, Dale (2007) Gliding motility and polarized slime secretion. Mol Microbiol 63:454-67
Gronewold, Thomas M A; Kaiser, Dale (2007) Mutations of the act promoter in Myxococcus xanthus. J Bacteriol 189:1836-44
Goldman, B S; Nierman, W C; Kaiser, D et al. (2006) Evolution of sensory complexity recorded in a myxobacterial genome. Proc Natl Acad Sci U S A 103:15200-5
Nudleman, Eric; Wall, Daniel; Kaiser, Dale (2006) Polar assembly of the type IV pilus secretin in Myxococcus xanthus. Mol Microbiol 60:16-29
Sozinova, Olga; Jiang, Yi; Kaiser, Dale et al. (2006) A three-dimensional model of myxobacterial fruiting-body formation. Proc Natl Acad Sci U S A 103:17255-9
Sozinova, Olga; Jiang, Yi; Kaiser, Dale et al. (2005) A three-dimensional model of myxobacterial aggregation by contact-mediated interactions. Proc Natl Acad Sci U S A 102:11308-12
Jelsbak, Lars; Givskov, Michael; Kaiser, Dale (2005) Enhancer-binding proteins with a forkhead-associated domain and the sigma54 regulon in Myxococcus xanthus fruiting body development. Proc Natl Acad Sci U S A 102:3010-5

Showing the most recent 10 out of 65 publications