Gene Vs Marker
The gene of interest is directly related with production of protein(s) that produce certain phenotypes whereas markers should not influence the trait of interest but are genetically linked (and so go together during segregation of gametes due to the concomitant reduction in homologous recombination between the marker and gene of interest). In many traits, genes are discovered and can be directly assayed for their presence with a high level of confidence. However, if a gene is not isolated, markers help is taken to tag a gene of interest. In such case there may be some inaccurate (even false) positive results due to recombination between the marker of interest and gene (or QTL). A perfect marker would elicit no false positive results.
Read more about this topic: Marker Assisted Selection
Famous quotes containing the word marker:
“Personal change, growth, development, identity formation—these tasks that once were thought to belong to childhood and adolescence alone now are recognized as part of adult life as well. Gone is the belief that adulthood is, or ought to be, a time of internal peace and comfort, that growing pains belong only to the young; gone the belief that these are marker events—a job, a mate, a child—through which we will pass into a life of relative ease.”
—Lillian Breslow Rubin (20th century)