Developing genomic platforms for Chinese hamster ovary cells

Chinese hamster ovary (CHO) cells are widely used in recombinant protein production, yet despite their importance in bioprocessing, few genomic resources have been developed for this cell line. Over the past several years, we have made considerable progress in the development of genomic tools for CHO. Using Sanger-based sequencing technology, we have accrued a sequence repertoire of more than 68,000 expressed sequence tags (ESTs), representing more than 28,000 unique CHO transcripts. Using closely related species, we have functionally annotated this sequence set and have currently achieved significant representation in a number of functional classes, including some closely tied to recombinant protein production. This sequence repository has been used to design custom CHO Affymetrix arrays for transcriptome analysis. Illumina Solexa deep sequencing technology was also applied to study the CHO cell transcriptome and survey the identity and expression of small RNAs. These applications demonstrate the utility of genomic tools, and illustrate the applicability of emerging next-generation sequencing technologies.