Work down the tree all the way to the bottom to narrow t down to some fixed values in one branch. Then work back up along the tree. In the process of working back up, some bad part of the tree may be eliminated using the best score got so far. That is, if partial score at some part of the tree is bigger than the best score, then that part can be eliminated. So one doesn t need to look every possible t value if using this method.
Patients are susceptible to chronic pulmonary infections.
In 1985, three research groups independently reported that the gene controls this disease was located on the seventh chromosome. By 1989, it was known that this gene is 27 kb in length, encodes contains 1480 amino acids, and has 27 exons. Recombinational DNA techniques were used to put normal CFTR gene into retrovirus. This recombinant retrovirus currently is being used to introduce a normal CFTR gene into the airway-lining cells of cystic fibrosis patients. Genetic mapping is, in short, to find the approximate locations and order of genes in genome.