"Cell" - what is it, definition of the term
The designation «Cell» denotes the fundamental structural and functional unit of living organisms, enclosed by a lipid bilayer membrane that separates internal cytoplasm from the external environment; it houses genetic material, organelles, and metabolic pathways that enable growth, replication, and response to stimuli, constituting the basic building block of tissues in mammals such as rats and mice.
Detailed information
The basic structural and functional unit of rodent organisms consists of a membrane‑bound compartment containing cytoplasmic material and genetic material. In rats and mice, this compartment exhibits diverse morphologies, ranging from elongated forms in muscle tissue to highly branched structures in neuronal networks. Each unit possesses a selectively permeable boundary that regulates the exchange of nutrients, ions, and signaling molecules, thereby maintaining internal homeostasis.
Metabolic activity within the compartment is driven by organelles that perform specialized tasks. Mitochondria generate adenosine triphosphate through oxidative phosphorylation, while the endoplasmic reticulum synthesizes proteins and lipids. The nucleus houses the genome, organized into chromosomes that encode species‑specific traits. In rodent models, the genome includes approximately 2.5 billion base pairs, with a high degree of similarity between the two species.
Key functional categories in these mammals include:
- Proliferative units: Stem‑like compartments located in the bone marrow and intestinal crypts, responsible for continuous renewal of tissue.
- Secretory units: Specialized compartments in pancreatic acini and salivary glands that release enzymes and hormones.
- Contractile units: Elongated compartments in skeletal and cardiac muscle that generate force through actin‑myosin interactions.
- Electrical units: Highly branched compartments in the central nervous system that propagate action potentials and support synaptic transmission.
Research applications frequently involve isolation and culture of these compartments from laboratory rodents. Standard protocols employ enzymatic dissociation with collagenase or trypsin, followed by centrifugation to obtain a purified suspension. Culture media are supplemented with fetal bovine serum, growth factors, and antibiotics to sustain viability and proliferation. Genetic manipulation techniques, such as CRISPR‑Cas9 editing, target the genomic material within the nucleus to create disease models or investigate gene function.
Physiological studies often measure parameters that reflect the health of these compartments. Common assays include:
- Viability assessment: Trypan blue exclusion or fluorescent dyes to determine membrane integrity.
- Metabolic profiling: Seahorse extracellular flux analysis to quantify oxygen consumption and glycolytic rates.
- Protein expression: Western blotting and immunofluorescence to detect specific markers, such as NeuN for neuronal compartments or MyoD for muscle compartments.
In toxicology, exposure to chemical agents can induce morphological changes, including swelling of the membrane‑bound boundary, fragmentation of organelles, and activation of programmed cell death pathways. Quantitative analysis of these alterations provides insight into the compound’s safety profile.
Overall, the compartmental organization in rats and mice underpins experimental reproducibility, enabling precise investigation of developmental processes, disease mechanisms, and therapeutic interventions. «The fundamental building block of mammalian biology» remains a central focus of biomedical research, with rodent models offering unparalleled access to genetic, physiological, and pharmacological data.