Related Experiment Video
Updated: Jun 13, 2026
08:03
In Vivo Calcium Imaging in C. elegans Body Wall Muscles
Published on: October 20, 2019
Calcium is required for coelomocyte activation in earthworms
Balázs Opper1, Péter Németh, Péter Engelmann
1Department of Immunology and Biotechnology, Clinical Center, University of Pécs, Szigeti u. 12, H-7643 Pécs, Hungary.
Molecular Immunology
|May 5, 2010
Summary
Calcium signaling is vital for immunity. This study reveals distinct calcium responses in earthworm immune cells (coelomocytes), suggesting its crucial role in innate immunity evolution.
Area of Science:
- Immunology
- Cell Biology
- Evolutionary Biology
Background:
- Calcium signaling is fundamental to immune activation in vertebrates.
- The evolutionary role of calcium in invertebrate immunity, particularly in earthworms, remains poorly understood.
- Coelomocytes are key cellular mediators of earthworm innate immunity, but their calcium dynamics are largely uncharacterized.
Purpose of the Study:
- To investigate basal and stimulated calcium (Ca2+) levels in coelomocyte subgroups of earthworms (Eisenia fetida and Allolobophora caliginosa).
- To explore the role of intracellular calcium stores and the impact of specific immune stimuli on coelomocyte calcium signaling.
- To elucidate the evolutionary significance of calcium signaling in the innate immune responses of invertebrates.
Main Methods:
- Utilized a calcium-sensitive dye and flow cytometry to measure intracellular Ca2+ levels in coelomocyte subpopulations.
- Applied various stimuli, including ionomycin, phorbol ester, thapsigargin, phytohemagglutinin (PHA), and formyl-methionyl-leucyl-phenylalanine (fMLP).
- Differentiated between Ca2+ influx and release from intracellular stores (endoplasmic reticulum).
Main Results:
- Eisenia fetida chloragocytes exhibited high basal Ca2+ but no influx upon stimulation, while other coelomocytes showed significant Ca2+ increase with ionomycin.
- Allolobophora caliginosa coelomocytes displayed weaker responses to ionophore, and chloragocytes showed no change.
- Phytohemagglutinin (PHA) increased Ca2+ in E. fetida coelomocytes, and fMLP induced calcium influx in Eisenia coelomocytes, with thapsigargin confirming endoplasmic reticulum calcium storage.
Conclusions:
- Coelomocyte subgroups display varied basal Ca2+ levels and differential responsiveness to immune stimuli, including mitogens and chemoattractants.
- Calcium influx and associated signal transduction pathways are likely critical components of earthworm innate immunity.
- These findings provide novel insights into the evolutionary conservation and function of calcium signaling in immune defense across diverse species.
Related Concept Videos
01:27Feedback Regulation of Calcium Concentration
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
01:16Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
01:21Skeleton and Calcium Homeostasis
Calcium is not only the most abundant mineral in bone but also the most abundant mineral in the human body. Calcium ions are needed for bone mineralization, tooth health, heart rate regulation and strength of contraction, blood coagulation, the contraction of smooth and skeletal muscle cells, and the regulation of nerve impulse conduction. The average calcium level in the blood is about 10 mg/dL. When the body cannot maintain this level, a person will experience hypo or hypercalcemia.
01:25Smooth Muscle Contraction
Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...