PICTURE OF THE DAY
Reverse genetics is a method in molecular genetics that is used to help understand the function of a gene by analysing the phenotypic effects of specific nucleic acid sequences after being genetically engineered. The process usually proceeds in the opposite direction to so-called forward genetic screens of classical genetics. In other words, while forward genetics seeks to find the genetic basis of a phenotype or trait, reverse genetics seeks to find what phenotypes arise as a result of particular genetic sequences. For instance, such procedures allow scientists to manipulate the genomes of influenza viruses by transferring genes between different strains. The novel genotypes of the viruses produced in this way have greatly diminished pathogenic potency but can still induce protective immunity in a host. Using this technique, vaccines can be created, as illustrated in this diagram depicting the development of an avian flu vaccine.