Cell Intelligence
Living cells continuously measure, process, and store cellular and environmental information. ~ Swiss biologists Simon Ausländer & Martin Fussenegger
Cells constantly sense their own health and level of stress. Various proteins, such as filamentous actin, act as sensors. Signals are passed to the cytoskeleton and into the endoplasmic reticulum, which decide how to respond, and then let the rest of the cell know what to do.
Living cells are complex systems that are constantly making decisions in response to internal or external signals; like a table around which decision makers debate and respond collectively to information put to them. ~ French biologist Emmanuel Levy
Cells know and control the size and composition of their organelles to meet immediate needs, and to efficaciously allocate resources. There are both dedicated reporters of organelle condition and indirect functional readouts. These are used to optimize organelles during normal and stressful conditions.
Through the extracellular matrix, cells sense their external environment: both chemical and mechanical characteristics. A stem cell relies upon this information to determine what type of cell it should become.
Certain cell proteins have receptors which discern a variety of chemical attributes. Others sense external softness or stiffness based upon the mechanical stress applied to bonds that proteins put out.
It is critical for cells, whether microbial or part of a larger organism, to adaptively configure their biochemical operations to current conditions. Cells do so through a host of measures, including altering protein production and self-manipulating their DNA. All cells intelligently manage their lives at the molecular level.
If a cell is unable to make copies of its DNA, or if it overlooks mistakes in the DNA code, the result can be the production of cancerous cells or cell death. So, cells continuously monitor their DNA for damage.
Cells are flexible in managing their DNA. When the normal tools of DNA replication are damaged, cells adaptively try to work around the problem.
Cells communicate through protein pathways. Especially in the embryo, and during times of stress, quick decisions must be made. Through a variety of techniques, cell networks rapidly perform analog computations using optimal decision theory algorithms. Based upon inputs from cells, an intercellular network cooperatively decides a proper response to a situation and disseminates its decision to its member cells.
An astonishing example of cell intelligence occurs during multicellular organism development. Morphogenesis is the process of how a heritable body plan grows from a single-cell embryo, through various stages, into an adult. From a single cell emerges a diversity of cell types and tissues which appear in a strictly regulated sequence.
A mother stem cell can mint a daughter cell that is genetically identical yet given a different cell fate based upon immediate developmental need. This it knows by information from its external environment, combined with knowledge from its vast genomic encyclopedia within and the ability to distinguish slight chromosomal and epigenetic differences. The information processing capability of cells exceeds what the human mind can consciously comprehend.
A human embryo begins with a single cell that relentlessly divides, creating more cells. All of these are pluripotent stem cells, able to differentiate into any cell type.
7 days into embryogenesis, cells begin to specialize, crafting tissues and organs. Cues from 2 distinct vectors determine morphogenesis: one is chemical, the other geometrical.
Energetic/genetic developmental plans include geographic arrangement. Cells know what is expected of them by where they are physically situated.
Further, cells know how large they are, and the precise topography of neighboring cells, including those of different types. They carry in their minds detailed 3d maps of what is and what should be (the genetic “standard” plan). Such extensive memory is necessary because cells may act as service providers to cells of another type.
Using their knowledge, cells self-organize. This is how tissues are built. Extracellular networking and cell adhesion molecules play constitutive roles.
