2020 Small World in Motion Competition

Cytoplasmic streaming in slime mold

Wim van Egmond

Affiliation
Micropolitan Museum
Berkel en Rodenrijs, Zuid-Holland, The Netherlands
Technique
Darkfield
Magnification
10X (Objective Lens Magnification)

Mr. van Egmond is a veteran freelance photographer and no doubt one of the most prolific winners in the Nikon Small World Competitions with nearly 40 images in the winner’s gallery. His latest winning contribution is of slime mold showing cytoplasmic streaming. Slime molds, which were long thought to be fungi, have been subsequently shown to be a type of amoeba. These fascinating creatures have even been shown to be capable of basic learning. Slime molds typically can become very large, easily seen by the naked eye however this microscopic example was tiny enough to offer transparency so the cytoplasmic streaming could be seen. The biggest challenge to imaging this creature is to place it on a microscope slide without harm and keeping it happy enough to display natural behavior. They typically are very slow and therefore a time-lapse over a significant period of time was required.

Endocardium, cells lining the heart chambers, in a beating heart of a living, 2 day old zebrafish (Danio rerio)

Anjalie Schlaeppi

Affiliation
Morgridge Institute for Research
Department of Medical Engineering
Madison, Wisconsin, USA
Technique

Selective Plane Illumination Microscopy (SPIM)

Magnification
16X (Objective Lens Magnification)

Anjalie Schlaeppi is a biologist working on early development of the zebrafish heart, specifically to better understand how the early embryonic heart pumps blood before valves have developed in the organ. This in vivo (in a live organism) movie was taken on a custom-built light sheet microscope using simultaneous 2-color acquisition. This rarely seen phenomena clearly shows the endocardium (the thin membrane that lines the inside of heart valves) repetitively contracting, effectively creating the pumping action before the valves have developed.