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Video archives
Here, we establish an online video library where a series of movies relevant to motility are available. The miscellaneous category includes bacteria, eukaryotes, and archaea, viruses, proteins, and synthetic polymers. The movies that are meaningful in the biology field will be uploaded in both Japanese and English.
For the contributors who plan to upload your video, you should keep in mind the following suggestions:
(1) the video which is relative to the object of your research
(2) the video about microbe found in the research activity of the super-science high school or biological clubs are encouraged to upload
(3) Do not forget to add the link of your video which has been published (Please make sure the copyright)
(4) If you think some videos in the old textbook are valuable to upload, please let us know.
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1
2014.09.15
Eukaryote number of click：249
Pollen tube attraction by the synergid cell
Species name:Torenia fournieri
ITbM, Nagoya Univ Tetsuya Higashiyama
In the evolution of flowering plants, genes necessary for flagella formation including flagellar dyneins were lost. Non-motile sperm cells of flowering plants are conveyed by a tip-growing haploid cell, the pollen tube. The sperm cell is enclosed by an endocytic membrane of the pollen tube cell and delivered to female gametes rapidly without much water for swimming. How does the pollen tube precisely arrive at an egg-containing tissue? Pollen tube attractants had been searched for more than 140 years. The attractants were finally identified in a unique plant species, Torenia, which has a protruding egg-containing tissue. Pollen tube attraction can be directly observed in Torenia as shown in this movie. Two synergid cells on the side of the egg cell were shown to be the source of the attraction signal. Finally, two cysteine-rich peptides named LUREs were identified as true pollen tube attractants.
2
2014.07.19
Molecule and Protein number of click：151
Movement of Actin-associated Myosin-II (Cross-Bridge) during Muscle Contraction
Species name:Rabbit
Osaka City Univ Eisaku KATAYAMA
The first part of the movie indicates the movement of individual myosin-head (crossbridge), based on conventional "Tilting-Leverarm Hypothesis". Such movement was proposed from the characteristic features of the atomic models of myosin-S1 in the absence and the presence of ATP, together with the well-known experimental evidence that "the motor-domain does not appreciably rotate during the Power-Stroke". Hence, this hypothesis claims that the Power-Stroke is essentially the transition between strongly actin-bound rigor-structure (1DFK: lever-arm is extended) and ATP-bound kinked structure (1DFL). If the motor-domain is immobilized on actin, the lever-arm moiety should swing along the actin filament, The latter half of the movie exhibits the revised crossbridge-cycle we have proposed according to our direct observation of in vitro sliding actomyosin by Quick-Freeze Deep-Etch Replica Electron Microscopy (Ref. 1, 2). We noticed that the actual images of actin-sliding myosin cannot be explained by the conventional hypothesis as above, suggesting the presence of a new conformer whose crystal structure is not yet reported. After extensive search, we finally found that SH1-SH2 crosslinked myosin could be a good candidate of the new conformer whose lever-arm bends to the opposite side of ATP-bound kinked structure (Ref.3-5). Since we could successfully reconstruct its low-resolution 3-D model by a new version of single-particle-analysis (Ref. 5). Taking the results of time-resolved chemical crosslinking into consideration, we revised the scheme of crossbridge-cycle including the new conformer (Ref.5). .The conformational change shown in the movie is compatible with all the images we actually observed under in vitro actin-sliding conditions. [References] 1. Katayama E. The effects of various nucleotides on the structure of actin-attached myosin subfragment-1 studied by quick-freeze deep-etch electron microscopy. J Biochem. 1989 Nov;106(5):751-70. 2: Katayama E. Quick-freeze deep-etch electron microscopy of the actin-heavy meromyosin complex during the in vitro motility assay. J Mol Biol. 1998 May 1;278(2):349-67. 3: Katayama E, Ohmori G, Baba N. Three-dimensional image analysis of myosin head in function as captured by quick-freeze deep-etch replica electron microscopy. Adv Exp Med Biol. 1998;453:37-45. 4: Katayama E, Ichise N, Yaeguchi N, Yoshizawa T, Maruta S, Baba N. Three-dimensional structural analysis of individual myosin heads under various functional states. Adv Exp Med Biol. 2003;538:295-304. 5: Kimori Y, Baba N, Katayama E. Novel configuration of a myosin II transient intermediate analogue revealed by quick-freeze deep-etch replica electron microscopy. Biochem J. 2013 Feb 15;450(1):23-35. 6. Andreev OA, Reshetnyak YK. Mechanism of formation of actomyosin interface. J Mol Biol. 2007 Jan 19;365(3):551-4.
3
2015.07.10
Eukaryote number of click：133
Mouse tracheal cilia
Species name:Mus musculus
Hamamatsu Univ Sch Med Koji Ikegami
Moving cilia on mouse tracheal epithelia. The beating frequency is about 10 to 20 Hz. The batch of cilia shows a wavelike motility, so-called metachronal wave.
4
2016.12.16
Eukaryote number of click：125
Euplotes： a skillful hunter
Species name:Euplotes
AL-Museum AL-Museum
A large Euplotes ciliate has characteristic cirri at the front and rear ends of its body. By actively waving the cilia surrounding its mouth, it creates a whirlpool to attract food particles. Several prey are drawn into its mouth and transferred inside, but some manage to get free.
5
2015.08.06
Eukaryote number of click：120
Mysterious behavior of Bacillaria
Species name:Bacillaria paxillifer
AL-Museum AL-Museum
Bacillaria is a colony in which numerous individual diatoms are connected. The individual diatoms are lined up side by side, which looks like a window blind when the colony is contracted. When the colony stretches out, the diatoms are connected nearly end to end in a long chain-like structure. Bacillaria usually moves in a straight line when extended, but can change directions freely when contracted. Various small diatoms, aggregates and crystals are stuck to Bacillaria and move along with it.
6
2015.07.19
Prokaryote number of click：118
Myxococcus Xanthus gliding motility (on TPM Agar)
Species name:Myxococcus Xanthus
Princeton University Akeisha Belgrave
Myxococcus Xanthus gliding motility (on TPM Agar)
7
2016.07.19
Eukaryote number of click：117
Epistylis sp.
Species name:Epistylis sp.
Bureau Swerage, Tokyo Metropolitan Government
The size of Epistylis is 5-90 μm in length. It might look like Vorticella, but Epistylis does not have myonemes. Epistylis sometimes stay in clusters. No myonemes result in immobility of stalk and whole body, but its oral can contract individually.
8
2016.07.15
Eukaryote number of click：116
How to elongate and divide?
Species name:Synura
AL-Museum AL-Museum
Various sizes of Synura(flagellate colonies) visit the big particle to forage for food. To share the food equally, the colony needs to rotate periodically so that each individual member can access the particle surface. Meanwhile, the number of cells in one of the colonies increases and the whole colony becomes larger, probably because the individual members have multiplied. However, becoming too large may be inconvenient, so here we can see the division of one big colony into two smaller ones.
9
2016.12.15
Eukaryote number of click：112
A flagellate surrounded by a brown shell
Species name:Euglena, Trachelomonas
AL-Museum AL-Museum
A round, dark brown flagellate with a long flagellum swims around for a while, then stops beside a particle, still waving its flagellum vigorously. A hard lorica surrounds the body, so this organism may belong to the group Trachelomonas.
10
2015.01.26
Eukaryote number of click：112
The gliding motion of diatom, Bacillaria paradoxa Part 1
Species name:Bacillaria paradoxa
Graduate School of Life Science, University of Hyogo Nozomi YAMAOKA
Bacillaria paradoxa belongs to pinnate diatom and forms a colony consisting of 2-30 cells, like a raft. Adjacent cells show active sliding each other. This gliding mechanism and physiological meanings are not understood. This motion looks like “Nankin Tamasudare”, a street performance using bamboo screens.