ABSTRACT
The skin of terrestrial animals is the primary interface between their body and the environment. As such, it affects social and sexual behaviors, regulates body temperature, triggers immunological responses to pathogenic microorganisms, and serves as a shield against environmental hazards. Most importantly, the skin provides a barrier that prevents the uncontrolled loss of water and ions. The detrimental effects of a loss of skin barrier function have been demonstrated by the phenotypes observed in animals with mutations in genes that encode either barrier components or enzymes required for barrier assembly.These genetically engineeredmousemutants oftendie shortly after birth due to uncontrolled transepithelial water loss (TEWL) and hypothermia (see below).
