title: Drosophila sperm motility in the reproductive tract.
abstract: Motile cilia and flagella exhibit many waveforms as outputs of dynein activation sequences on the highly conserved axoneme. Motility change of sperm in the reproductive tract is difficult to study and remains an important area of investigation. Sperm typically execute a sinusoidal waveform. Increased viscosity in the medium induces somewhat unusual arc-line and helical waveforms in some sperm. However, whether the latter two waveforms occur in vivo is not known. Using green fluorescence protein imaging, we show that Drosophila sperm in the uterus move in circular foci via arc-line waves, predominantly in a tail-leading orientation. From the uterus, a small fraction of the sperm enters the seminal receptacle (SR) in parallel formations. After sperm storage and coincident with fertilization of the egg, the sperm exit the SR via head-leading helical waves. Consistent with the observed bidirectional movements, the sperm show the ability to propagate both base-to-tip and tip-to-base flagellar waves. Numerous studies have shown that sperm motility is regulated by intraflagellar calcium concentrations; in particular, the Pkd2 calcium channel has been shown to affect sperm storage. Our analyses here suggest that Pkd2 is required for the sperm to adopt the correct waveform and movement orientation during SR entry. A working model for the sperm's SR entry movement is proposed.
authors.affiliation: Institute of Environmental Health Sciences and Department of Biochemistry and Molecular Biology, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.forename: Xiangyi
authors.initials: X
authors.lastname: Lu
mesh_terms: D000290:Adnexa Uteri / Q000502:physiology; D000818:Animals; D030801:Animals, Genetically Modified; D004331:Drosophila melanogaster / Q000502:physiology*; D005260:Female; D005306:Fertilization; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D019476:Insect Proteins / Q000378:metabolism; D008297:Male; D018715:Microscopy, Video; D008954:Models, Biological; D000091283:Protein Kinase D2; D011494:Protein Kinases / Q000378:metabolism; D055101:Semen Analysis / Q000379:methods; D013081:Sperm Motility; D013082:Sperm Tail / Q000502:physiology; D013083:Sperm Transport; D013094:Spermatozoa / Q000201:enzymology / Q000502:physiology*; D014599:Uterus / Q000502:physiology
chemical_list: D019476:Insect Proteins; D000091283:Protein Kinase D2; D049452:Green Fluorescent Proteins; D011494:Protein Kinases