Diversity of Chemotaxis

Motility type Energy source Mechanism Species Book chapter 

Swimming by H -motive Flux of H ions through Some bacteria 3 

Swimming by a bending-and-pushing flagellum ATP Active sliding of microtubules, carried out by attachment/ detachment of the dynein arms Spermatozoa of most species 7 

Swimming without flagella Not known Not known Some marine cyanobacteria (e.g., Synechococcus) 3 

Swarming H -motive force Flux of If ions through If channels rotates the flagellar motor Some bacteria (e.g., E. coli. Vibrio) 3 

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Beyond this universal, general framework, the molecular mechanisms of chemotaxis involve both commonalities and diversities. Generally speaking, the molecular mechanisms of prokaryotes and eukaryotes are different. Within the prokaryotes, however, commonality seems to govern. Within the eukaryotes, both commonality and diversity appear to dominate (Table 3). 

The G-protein coupled receptor (GPCR) family is the largest receptor superfamily in mammalian genomes (Kabbani et al. 2005) and its members are involved in diverse functions from neurotransmission to chemotaxis and many other important physiological processes. This family of receptors is the target for over 50% of all medicines and characterisation of associated proteins in GPCR complexes may aid the discovery of novel modes of pharmaceutical modulation of GPCR-associated functions. 

We are grateful to all the authors for contributing their expertise and believe that this book will provide the reader with an overview of and practical guidance on the diverse methodologies that are propelling chemotaxis research forward. 

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