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Weak Points Detection



, with an overlap oi,j = t and hybridization fingerprints is given by $E_{i,j} = - \lg
Pr(\overrightarrow{B_{i}} ,\overrightarrow{B_{j}} \vert o_{i,j} = t )$.  
\begin{dfn}{\rm The {\em contig energy E} is given by} \end{dfn}
summing over all clones in the contig ,i.e : $E = \sum_{i<j}
E_{i,j}$. In analogy to the breaking ­ up of a chemical molecule, the separation of a contig into two non­overlapping parts should increase the energy substantially. However, if the two parts do not overlap in the real map, the separation energy should be quite small or even negative.  
\begin{dfn}{\rm A {\em weak point} is a point along the
contig having separation energy below a threshold (determined
experimentally).} \end{dfn}
Such information can be used by the laboratory in order to pinpoint areas where additional hybridizations should be performed. We also make use of the weak points in our algorithm in order to break up a contig and reassemble it. In case an error was made at an early stage, this process enables the algorithm to correct its previous error with the benefit of the additional information from other clones added at a later stage.

Itshack Pe`er
1999-03-21