Eukaryotic cell
Locomotion of Amoeba proteus

Species name: Amoeba proteus
University of Hyogo, Graduate School of Life Science　Yukinori Nishigami

Amoeba proteus exhibit active cell locomotion. During locomotion, cytoplasm actively flows toword direction of locomotion.

Model (CG)
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.

Eukaryotic cell
Euglenoid movement of Euglena

Species name: Euglena
Department of Biology, Faculty of Science, Kobe University　Masashi HAYAKAWA

Euglenoid movement of Euglena

Others
Evidence of swimming P-Chlamydomonas cell lens effect (Kenichi Wakabayashi, Laboratory for Chemistry and life science, Tokyo Institute of Technology)

The Biophysical Society of Japan　annual meeting executive committee 2019

Green algae Chlamydomonas recognizes the direction of the light source by the eye point and exhibits phototaxis. The eye point performs highly directional photoreception by lining the photoreceptor on the cell membrane with a dye layer acting as a light reflector. We isolated a mutant that swims in the opposite direction to the wild type strain, and found that the cause was a defect in the pigment layer. The reason for swimming in the opposite direction was that the eye point that lost the pigment layer felt that the light collected by the lens effect through the cell was stronger than the light coming from the front and misidentified the direction of the light source. However reviewers said Chlamydomonas can never be a convex lens. We put the letter P (the acronym for photo) in the optical path of the microscope, and thought that it could be countered if the letter P was visible on the cell. The results are as you can see (Ueki, Ide et al., 2016 PNAS) Microscope: Olympus BX-53, Camera: Omron Sentec STC-MCA5MUSB3

Others
Walking baby sea urchin

Species name: Hemicentrotus pulcherrimus
National Defense Medical college, Laboratory of Biology　Tatsuhiko Noguchi

Young baby sea urchin walking with their tube feet on the surface of glass dish. Sea urchin embryo develops into pluteus larva first, which can swim in sea water freely. For a month or so, it catches tiny planktons to grow bigger. Then, they metamorphose into baby sea urchin that no longer swim but walk on the sea bed searching for seaweed.

Eukaryotic cell
Locomotion of Amoeba

Species name: Amoeba proteus
National Institute for Basic Biology　TANIGUCHI, Atsushi

Locomotion of Amoeba

Eukaryotic cell
Metachronal Wave of Cilia

Species name: Paramecium caudatum
Fac. Sci., Yamaguchi Univ.　Yoshiaki Iwadate

The surface of ciliated protozoa, such as Paramecium cells, is covered with a dense array of cilia. Ciliary movements exhibit beautiful metachronal wave-like coordination where a constant phase difference is maintained between adjacent cilia.

Model (CG)
Updated centipede model for Mycoplasma mobile gliding

Species name: Mycoplasma mobile
Osaka City Univ　Makoto MIYATA, Tasuku HAMAGUCHI

supplemented to a scientific paper Prospects for the gliding mechanism of Mycoplasma mobile Makoto Miyata, Tasuku Hamaguchi (Osaka City University) doi:10.1016/j.mib.2015.08.010 end user license: CC BY-NC-ND 4.0

Miyata M, Hamaguchi T, Prospects for the gliding mechanism of Mycoplasma mobile. Current Opinion in Microbiology. 29, 15-21.

Eukaryotic cell
SPOC(Myofibril in auxotonic condition)

Waseda Univerisity　Shin'ichi ISHIWATA

SPOC(Myofibril in auxotonic condition)

Model (CG)
Quick freezing by Blender

Osaka City University　Hamaguchi Tasuku

Quick freezing made by Blender (free- software).

Model (CG)
Flagellar helical form: Normal, CW rotation. Polymorphic transition.

Faculty of Life and Environmental Scienses, Prefectural University of Hiroshima　Shin-ichi Aizawa

Bacterial flagellar filament has polymorphic transition ability, which can switch between a set of helical forms (straight, Normal coiled and curly) in response to flagellar motor rotation, pH, salinity, and temperature changes.

Lecture

Osaka City University　Makoto Miyata

The research team of Dr. Makoto Miyata (Graduate School of Science, Osaka City University), conducted the research of "Harmonized supramolecular motility machinery and its diversity " supported by the Ministry of Education, Culture, Sports, Science and Technology by 47 research teams from 2012 to 2018. Based on the experimental results and discussions obtained from this study, they proposed for the first time the origin and evolution of all motility discovered so far. This content was published in "Genes to Cells", a European journal of the Molecular Biology Society of Japan, on January 20, 2020.

Others
Retina 2: Swim inside the retina (Shinya Sato, Graduate school of biostudies, Kyoto Unibersity)

The Biophysical Society of Japan　annual meeting executive committee 2019

Summary: Retinas were isolated from mice expressing fluorescent proteins in the cytoplasm of whole cells, and tomographic images were taken at 1 µm intervals from the surface to 200 µm deep using a multiphoton microscope. The moving image is obtained by reconstructing the stack image data in the depth direction into a continuous tomographic image from the side of the retina by image processing, and it feels like swimming in the retina. <Highlights> The photoreceptor nuclei are beautifully arranged vertically in 9 to 10 layers for a reason. It is said that nocturnal organisms such as mice have a special structure of photoreceptor nucleus in which heterochromatin is localized in the central part, and this acts as a microlens, thereby guiding incident light linearly. Camera:Olympus multiphoton laser scanning microscope

Eukaryotic cell
Standard SPOC

Waseda Univerisity　Shin'ichi ISHIWATA

Standard SPOC

Eukaryotic cell
Macrobiotus sp.

Species name: Macrobiotus sp.
Tokyo Metropolitan Government　Bureau Swerage,

The size of Macrobiotus is about 0.2 – 1.0 mm. The body is covered with a thin chitin film, with spiny bristles, armor plates. There are four pairs of footsteps, with nails at the tip. Macrobiotus have fourth pair of legs with nails at the tip. They usually live in soil. The form that I'm slow in action and walk slowly is similar to a bear, so it's called a bear bug. The tooth needle taken out of the mouth is stuck into food, and it's crowded, and a pharynx, to work, more, I suck at contents. Slowly walking figure resembles a bear so it is called water bears.

微生物図鑑

Eukaryotic cell
Paramecium caudatum

Species name: Paramecium caudatum
Faculty of Medicine, Yamaguchi University　IWADATE, Yoshiaki

Movement of Paramecium with cilia.

Meeting
Dr. Nagai wearing a Hyottoko mask at the party of annual meeting of the Biophysical Society 2019

The Biophysical Society of Japan　annual meeting executive committee 2019

Dr. Nagai wearing a Hyottoko mask at the party of annual meeting of the Biophysical Society 2019

Meeting
Dr. Kabayama at the party of annual meeting of the Biophysical Society 2019

The Biophysical Society of Japan　annual meeting executive committee 2019

Dr. Kabayama at the party of annual meeting of the Biophysical Society 2019

Prokaryotic cell
Motility of Paenibacillus sp. NAIST15-1 (4)

Species name: Paenibacillus sp.
Graduate School of Biological Sciences, Nara Institute of Science & Technology　Kazuo Kobayashi

The cmoA mutant retains functional flagella. cmoA mutant cells were spread over the surface of a 1.5% agar plate and incubated at 37°C for 5 h. Two hundred microliters of water were poured onto the colonies and cellular behavior was immediately observed under a video light microscope. The movie is real time. Scale bar, 20 μm.

Genetic Analysis of Collective Motility of Paenibacillus sp. NAIST15-1

Lecture
Audioslide for "Prospects for the gliding mechanism of Mycoplasma mobile"

Osaka City Univ　Makoto Miyata and Tasuku Hamaguchi

Current Opinion in Microbiology Volume 29, February 2016, Pages 15–21 doi:10.1016/j.mib.2015.08.010

http://www.sciencedirect.com/science/article/pii/S1369527415001307