Flagella are important protein structures on the cell surface of bacteria and the main appendage for bacterial swimming. Flagella play a crucial role in bacterial motility, chemotaxis, pathogenicity, and environmental sensing. With the development of microscopic tracking technology and flagellum visualization tools, new forms of flagellar motility and increasing roles of flagella in the physiological activities of bacteria have been discovered. This review introduces the visualization methods of flagella and the applications of these methods in studying flagellar functions, giving insights into exploring the functions of flagella and laying a theoretical foundation for its future applications in inhibiting bacterial transmission and treating bacterial infections.
Flagella/physiology* ; Bacterial Physiological Phenomena ; Chemotaxis/physiology* ; Bacteria

Bacterial Proteins ; genetics ; metabolism ; Biofilms ; DNA-Binding Proteins ; genetics ; metabolism ; Flagella ; genetics ; metabolism ; Gene Expression Regulation, Bacterial ; Transcription Factors ; genetics ; metabolism ; Vibrio parahaemolyticus ; cytology ; genetics ; growth & development ; physiology

To investigate the function of STT3a gene in salt adaptation and flagellar regeneration of Dunaliella salina (D. salina), a pair of degenerate primers was designed according to conserved homologous amino acid sequences of VCVFTA and DVDYVL of STT3a from Chlamydomonas, Arabidopsis thaliana and other organisms. A cDNA sequence of 1 650 bp encoding a whole functional domain of STT3a was amplified from D. salina by RT-PCR and 3' Rapid Amplification of cDNA Ends (RACE), which shared homology with Chlamydomonas (48%), Arabidopsis thaliana (50%), Homo sapiens (46%), etc. Real-time fluorescence quantitative PCR (real-time Q-PCR) demonstrated that the STT3a mRNAs from D. salina were induced by increased concentration of NaCl, and increased to 11-fold higher by 3.5 mol/L NaCl than that by 1.5 mol/L NaCl (P < 0.01). Also, STT3a mRNA of D. salina maintained at a higher level in the process of flagellar regeneration with than without experiencing deflagellar treatment. In conclusion, the findings of this study demonstrate that the high expression of the STT3a gene enhances the capability of salt adaptation and flagellar regeneration in D. salina.
Adaptation, Physiological ; physiology ; Arabidopsis ; enzymology ; Chlamydomonas ; enzymology ; Chlorophyta ; enzymology ; genetics ; Cloning, Molecular ; Flagella ; metabolism ; Hexosyltransferases ; chemistry ; genetics ; metabolism ; Membrane Proteins ; chemistry ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; genetics ; metabolism ; Sodium Chloride ; pharmacology

One of the most widespread cellular organelles in nature is cilium, which is found in many unicellular and multicellular organisms. Formerly thought to be a mostly vestigial organelle, the cilium has been discovered in the past several decades to play critical motile and sensory roles involved in normal organogenesis during development. The role of cilia has also been implicated in an ever increasing array of seemingly unrelated human diseases, including blindness, kidney cysts, neural tube defects and obesity. In this article we review some of the recent developments in research on cilia, and how defects in ciliogenesis and function can give rise to developmental disorders and disease.
Abnormalities, Multiple ; pathology ; Animals ; Cerebellar Diseases ; genetics ; pathology ; Cilia ; physiology ; ultrastructure ; Flagella ; physiology ; Hedgehog Proteins ; metabolism ; Humans ; Models, Animal ; Polycystic Kidney Diseases ; pathology ; Protein Transport ; Signal Transduction ; Wnt Proteins ; metabolism

AIMTo investigate the human sperm oxygen/energy consumption and zinc content in relation to motility.

METHODSIn washed spermatozoa from 67 ejaculates, the oxygen consumption was determined. Following calculation of the total oxygen consumed by the Ideal Gas Law, the energy consumption of spermatozoa was calculated. In addition, the zinc content of the sperm was determined using an atomic absorption spectrometer. The resulting data were correlated to the vitality and motility.

RESULTSThe oxygen consumption averaged 0.24 micromol/10(6) sperm x 24h, 0.28 micromol/10(6) live sperm x 24h and 0.85 micromol/10(6) live motile sperm x 24h. Further calculations revealed that sperm motility was the most energy consuming process (164.31 mJ/10(6) motile spermatozoa x 24h), while the oxygen consumption of the total spermatozoa was 46.06 mJ/10(6) spermatozoa x 24h. The correlation of the oxygen/energy consumption and zinc content with motility showed significant negative correlations (r= -0.759; P<0.0001 and r=-0.441; P<0.0001, respectively). However, when correlating sperm energy consumption with the zinc content, a significant positive relation (r=0.323; P=0.01) was observed.

CONCLUSIONPoorly motile sperm are actually wasting the available energy. Moreover, our data clearly support the "Geometric Clutch Model" of the axoneme function and demonstrate the importance of the outer dense fibers for the generation of sperm motility, especially progressive motility.

Adult ; Energy Metabolism ; physiology ; Flagella ; physiology ; Humans ; Male ; Middle Aged ; Oxygen Consumption ; Sperm Motility ; physiology ; Spermatozoa ; metabolism ; Zinc ; metabolism