Leslie Burnett

Differential co-expression of α-actin genes within the human heart

Human cardiac muscle has been studied to determine whether the ratio of cardiac alpha-actin to skeletal alpha-actin varies between the different chambers of the human heart taken from a single individual. Using mRNA dot-blots, and DNA probes specific for the cardiac and skeletal alpha-actin isotypes, we have found that both cardiac and skeletal alpha-actin mRNAs are present and co-expressed throughout the human heart. The pattern of alpha-actin co-expression in the left and right ventricles and in the interventricular septum is approximately the same, with cardiac alpha-actin being the dominant isotype (approx. 80% of total). However, the left atrium has a different relative composition of the two actins, with an even higher level of cardiac alpha-actin expression (95% of total).

An exhaustive tree-searching algorithm for high-resolution computer-assisted nucleotide sequence analysis

A new computer search strategy has been devised for high-resolution nucleotide sequence analysis. The strategy differs from those used by earlier sequence analysing programs in that it is exhaustive and capable of detecting all possible homologies and other types of relationships between or within sequences irrespective of the pattern of matches and mismatches encountered. The implementation of this strategy into a working algorithm is described.

Should nucleotide sequence analyzing computer algorithms always extend homologies by extending homologies

Most computer algorithms used for comparing or aligning nucleotide sequences rely on the premise that the best way to extend a homology between the two sequences is to select a match rather than a mismatch. We have tested this assumption and found that it is not always valid.

The SEQANAL and SEQTALK programs: a new method of access to high-resolution nucleotide sequence comparison and analysis programs from a remote laboratory mini- or microcomputer

A new method of access has been devised for biologists requiring the use of computer programs offering high-resolution analysis and comparison of nucleotide sequence data. The strategy involves the development of a pair of computer programs, called SEQANAL and SEQTALK, designed to operate in tandem. SEQANAL is a large and complex program intended to be used to discover regions of internal repeats and dyad symmetries within one sequence, or regions of homology, complementarity or optimal alignment between two sequences. Three algorithms are supported: those of Staden (1977, 1978); of Korn et al. (1977); Queen and Korn (1980); and the newly-described exhaustive tree-searching algorithm of Burnett et al. (1985, 1986). The SEQTALK program is a small, portable, interactive, front-end program with which the user can specify the instructions to control the SEQANAL program. Together, the SEQANAL and SEQTALK programs permit analyses to be performed at a remote facility on a mainframe computer under the complete control of a distant user equipped with minimal computing facilities, and without needing networking facilities.