Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Poster: Microbial Sequencing and Genome Programs
            

RELATIVE EXPRESSION LEVELS OF A SUITE OF ISOTRICHA EST

¹ Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta, Canada, T1J 4B1

Protozoa represent a major component of rumen microbial populations in sheep, cattle and other ruminants. Although non-essential for survival, rumen protozoa play important roles in maintaining the health and productivity of host animals by reducing the risk of lactic acidosis, and by contributing to the breakdown of cellulose and other fibre components of the diet. As a first step towards the characterization of rumen protozoa at the molecular level, we have constructed a cDNA library for Isotricha sp., a common rumen Holotrich ciliate, and characterized a suite of randomly chosen cDNA clones by partial sequencing and expression analysis. Of the sixty-two clones used for expression profiling, transcript levels ranged from high (five clones) to below the detection threshold of assay (twenty-eight clones). Among the twenty-nine clones sequenced, the high level expressors, polyubiquitin and ubiquitin, occurred three and two times respectively - all other sequences occurred only once. Nineteen cDNAs showed homology to known sequences in GenBank, and one clone was similar to a hypothetical gene/protein from C. elegans. The remaining cDNAs represent novel sequences with no homology to known sequences in GenBank.