Survival Under Stressful Conditions
Transformation is a bacterial adaptation involving the transfer of DNA from one bacterium to another through the surrounding medium (see Transformation (genetics)). Transformation is a primitive form of sex (see Sexual reproduction). For a bacterium to bind, take up, and recombine exogenous DNA into its chromosome it must enter a special physiological state termed “competence” (see Natural competence). In S. mutans, a peptide pheromone quorum-sensing signaling system controls genetic competence. This system functions optimally when the S. mutans cells are in crowded biofilms. S. mutans cells growing in a biofilm are transformed at a rate 10- to 600-fold higher than single cells growing under uncrowded conditions (planktonic cells). Induction of competence appears to be an adaptation for repairing DNA damages caused by crowded, stressful conditions (see Natural competence and Michod et al.).
Read more about this topic: Streptococcus Mutans
Famous quotes containing the words survival, stressful and/or conditions:
“...I have a duty to speak the truth as I see it and to share not just my triumphs, not just the things that felt good, but the pain, the intense, often unmitigating pain. It is important to share how I know survival is survival and not just a walk through the rain.”
—Audre Lorde (1934–1992)
“It is not stressful circumstances, as such, that do harm to children. Rather, it is the quality of their interpersonal relationships and their transactions with the wider social and material environment that lead to behavioral, emotional, and physical health problems. If stress matters, it is in terms of how it influences the relationships that are important to the child.”
—Felton Earls (20th century)
“... we have every reason to rejoice when there are so many gains and when favorable conditions abound on every hand. The end is not yet in sight, but it can not be far away. The road before us is shorter than the road behind.”
—Lucy Stone (1818–1893)