If biologists have ignored self-organization, it is not because self-ordering is not pervasive and profound. It is because we biologists have yet to understand how to think about systems governed simultaneously by two sources of order, Yet who seeing the snowflake, who seeing simple lipid molecules cast adrift in water forming themselves into cell-like hollow lipid vesicles, who seeing the potential for the crystallization of life in swarms of reacting molecules, who seeing the stunning order for free in networks linking tens upon tens of thousands of variables, can fail to entertain a central thought: if ever we are to attain a final theory in biology, we will surely, surely have to understand the commingling of self-organization and selection. We will have to see that we are the natural expressions of a deeper order. Ultimately, we will discover in our creation myth that we are expected after all.
[Stuart Kauffman, At Home in the Universe, 1995, p112]
In the interests of promoting science posts relating (however broadly) to my interests of cell and molecular biology, here’s my weekly installment of “Cells Weekly,” a showcase of topical blog posts by others from the past week. In in the interest of consolidating the relatively few number of thorough posts on cell and molecular biology, I’m switching to “Cells BiWeekly” as of next week. In the meantime, Enjoy!
Minicells on Target – Moselio explains the use of bacterial minicells to selectively target cancer cells, which is an important goal for oncologists, as they attempt to reduce the side-effects of chemotherapy. At Small Things Considered.
RecA – An Evolution Gene – MikeGene has conceived of the possible existence of “Evolution Genes,” and goes looking for candidates (psst – crank alert!). In actuality, the candidate that he looks at, RecA, influences antigenic variation by homologous recombination; while it therefore facilitates selective change, it does so naturally, and presumably RecA itself evolved naturally from an ancestral gene product (Karlin & Brocchieri, 1996). So it’s only as “intelligently designed” as MikeGene imagines it to be. At The Design Matrix.
Immunofluorescence: Why Color is Bad – Alex reprises a few tips that every budding microscopist should know, while he’s away. At The Daily Transcript.
And four ScienceDaily picks, below the fold…
Effects Of Aging In Stem Cells
There is little disagreement that the body’s maintenance and repair systems deteriorate with age, even as there is plenty of disagreement as to why. Stem cells combat the aging process by replenishing old or damaged cells–particularly in the skin, gut, and blood–with a fresh supply to maintain and repair tissue. Unfortunately, new evidence suggests that this regenerative capacity also declines with age as stem cells acquire functional defects. In highly purified hematopoietic stem cells from mice aged 2 to 21 months, gene expression analysis indicates a deficit in function, yet an increase in stem cell number with advancing age.
Scientists have discovered a biological process in brain cell development that may help explain some causes of mental retardation. This understanding may one day help other researchers develop therapies that can reduce specific forms of retardation. Proteins of the Rho family, when excessively present in developing brain cells known as neurons, inhibit another protein, called cypin, that promotes healthy neuron development.
Scientists have discovered an important mechanism for controlling the behavior of adult stem cells. Research with the flatworm, planaria, found a novel role for the proteins involved in cell-to-cell communication. This work has the potential to help scientists understand the nature of the messages that control stem cell regulation — such as the message that maintain and tells a stem cell to specialize and to become part of an organ (e.g., liver or skin).
Researchers have developed a model that could predict how cells will respond to targeted drug therapies. Models based on this approach could help doctors make better treatment choices and drug developers identify the ideal compound. In addition, the model could help test the effectiveness of drugs for a wide range of diseases, including cancer, arthirtis, and immune system disorders.