Leave It to Lymph
This abstract array of blue, green, and orange swirls depicts an important bodily system, the lymphatic system, which produces immune cells and transports them throughout the bodies of all vertebrates.
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DownloadLeave It to Lymph
This abstract array of blue, green, and orange swirls depicts an important bodily system, the lymphatic system, which produces immune cells and transports them throughout the bodies of all vertebrates.
What am I looking at?
This is a sample of so-called interbranchial lymphoid tissue (ILT) from the gills of a salmon. Immune cells called T cells are green (1). A structural protein called actin is orange (2). The cells’ nuclei are blue (3).
Biology in the background
Fish use their gills to extract oxygen from the water. However, as water passes over the gills, they are exposed to microorganisms and debris in the water that could infect or damage the sensitive gill tissue. Fish have developed lymphatic organs in their gill cavities that harbor immune cells to help fight infection and clear debris from around the gills. This lymphoid tissue also contains cells that produce mucus, which coats the gills and helps trap hazardous microorganisms and debris, allowing the immune cells to concentrate their efforts.
This section of lymphoid tissue is about 730 micrometers across, or roughly 10 times larger than the width of a human hair.
Technique
This image was created using confocal microscopy.
Julien Resseguier, University of Oslo