Identification and Characterisation of Bovine Bidirectional Promoters

Bidirectional promoters are found in many species, where they represent approximately 3 to 5% of the genome. These promoters have the peculiarity to regulate the expression of two neighboring genes located in a head-to-head position. Bidirectional promoters have been studied in many mammalian organisms, and the conservation of such a genomic architecture during evolution incites to study the functioning of this type of genes. Currently, studies were been done in Human and other Primates, in Dog, Mouse, but also in Fugu, Zebrafish, as well as Saccharomyces cerevisiae.

We are interested in the study of bidirectional promoters in Cattle (Bos taurus) and to then look for those that are conserved with Human.

Using the ENSEMBL database, we identified 638 pairs of head-to-head genes that are separated by less than 1,500 bp. A similar study in Human had allowed the identification of 1,352 potential bidirectional promoters. To overcome problems with paralogous genes, we removed this type of genes; 198 gene pairs remained. In order to compare bidirectional promoters shared between Cattle and Human, a search for orthologous genes between these two species was performed, allowing the identification of 52 putative conserved bidirectional promoters.

A comparative study of the genomic sequences of these 52 putative bidirectional promoters will be presented.