In response to certain extracellular stimuli, Chlamydomonas reinhardtii cells excise their flagella, induce expression of more than 200 different flagellar mRNAs, and assemble a new flagellar pair. Normally, flagellar excision, gene induction and outgrowth are tightly coupled temporally. Our previous studies showed that uncoupling the cellular response of flagellar excision from flagellar outgr...

Chlamydomonas cells respond to certain environmental stimuli by shedding their flagella. Flagellar loss induces a rapid, transient increase in expression of a specific set of genes encoding flagellar proteins, and assembly of a new flagellar pair. While flagellar gene expression and initiation of flagellar outgrowth are normally tightly coupled to flagellar excision, our results demonstrate tha...

Propulsion at microscopic scales is often achieved through propagating traveling waves along hairlike organelles called flagella. Taylor's two-dimensional swimming sheet model is frequently used to provide insight into problems of flagellar propulsion. We derive numerically the large-amplitude wave form of the two-dimensional swimming sheet that yields optimum hydrodynamic efficiency: the ratio...

Chlamydomonas cells respond to certain environmental stimuli by shedding their flagella . Flagellar loss induces a rapid, transient increase in expression of a specific set of genes encoding flagellar proteins, and assembly of a new flagellar pair. While flagellar gene expression and initiation of flagellar outgrowth are normally tightly coupled to flagellar excision, our results demonstrate th...

The swimming of a micro-organism by the propagation of helical waves on a long slender flagellum is analysed. The model developed by Higdon (1979) is used to study the motion of an organism with a spherical cell body (radius A ) propelled by a cylindrical flagellum (radius a, length L). The average swimming speed and power consumption are calculated for helical waves (amplitude a, wavenumber k)...

The specific and selective detection of Salmonella typhymurium based on the use of a polyclonal antibody immobilized by the Langmuir-Blodgett method on the surface of a quartz crystal acoustic wave device was demonstrated in liquid samples. These biosensors were selective to S. typhymurium in the presence of large concentrations of Escherichia coli O157:H7. They were also specific to S. typhymu...

Spirochetes are bacteria characterized in part by rotating periplasmic flagella that impart their helical or flat-wave morphology and motility. While most other bacteria rely on a transcriptional cascade to regulate the expression of motility genes, spirochetes employ post-transcriptional mechanism(s) that are only partially known. In the present study, we characterize a spontaneous non-motile ...

ABSTRACT Human spermatozoa are the archetype of long-term self-organizing transport in nature and critical for reproductive success. They utilize coordinated head flagellar movements to swim long distances within female tract order find fertilize egg. However, date, analysis sperm head–flagellar movements, or indeed those other flagellated microorganisms, remains elusive due limitations microsc...

The transcription of flagellar genes in Caulobacter crescentus is regulated by cell cycle events that culminate in the synthesis of a new flagellum once every cell division. Early flagellar gene products regulate the expression of late flagellar genes at two distinct stages of the flagellar trans-acting hierarchy. Here we investigate the coupling of early flagellar biogenesis with middle and la...

The antiphosphoprotein monoclonal antibody MPM-2 was used to investigate protein phosphorylation during flagellar regeneration in Chlamydomonas reinhardtii. MPM-2 recognizes a phosphorylated epitope and detects several Chlamydomonas proteins by Western immunoblot analysis. Two MPM-2 reactive proteins (34 and 90 kD) increase in Western immunoblot intensity after flagellar excision and decrease i...