Conservation and divergence of known apicomplexan transcriptional regulons

<p>Abstract</p> <p>Background</p> <p>The apicomplexans are a diverse phylum of parasites causing an assortment of diseases including malaria in a wide variety of animals and lymphoproliferation in cattle. Little is known about how these varied parasites regulate their transcriptional regulons. Even less is known about how regulon systems, consisting of transcription factors and target genes together with their associated biological process, evolve in these diverse parasites.</p> <p>Results</p> <p>In order to obtain insights into the differences in transcriptional regulation between these parasites we compared the orthology profiles of putative malaria transcription factors across species and examined the enrichment patterns of four binding sites across eleven apicomplexans.</p> <p>About three-fifths of the factors are broadly conserved in several phylogenetic orders of sequenced apicomplexans. This observation suggests the existence of regulons whose regulation is conserved across this ancient phylum. Transcription factors not broadly conserved across the phylum are possibly involved in regulon systems that have diverged between species. Examining binding site enrichment patterns in light of transcription factor conservation patterns suggests a second mode via which regulon systems may diverge - rewiring of existing transcription factors and their associated binding sites in specific ways. Integrating binding sites with transcription factor conservation patterns also facilitated prediction of putative regulators for one of the binding sites.</p> <p>Conclusions</p> <p>Even though transcription factors are underrepresented in apicomplexans, the distribution of these factors and their associated regulons reflect common and family-specific transcriptional regulatory processes.</p

Syntactic Complexity Metrics and the Readability of Programs in a Functional Computer Language

This article reports on the defintion and the measutement of the software complexity metrics of Halstead and McCabe for programs written in the functional programming language Miranda. An automated measurement of these metrics is described. In a case study, the correlation is established between the complexity metrics and the expert assessment of the readability of programs in Miranda, and compared with those for programs in Pascal