Construction of a Bacterial Artificial Chromosome (BAC) library and the genomic analysis of valosine-containing proteins in the earthworm Eisenia fetida

In an attempt to isolate gonad-related genes from the earthworm Eisenia fetida (Savigny, 1826), we have isolated two genes with sequence similarities to mammalian valosine-containing proteins (evcp-1 and evcp-2) [T. Suzuki, M. Honda, S. Matsumoto, S.R. Stürzenbaum, S. Gamou. Valosine-containing proteins (VCP) in an annelid: identification of a novel spermatogenesis related factor, Gene 362 (2005) 11–18]. To understand the origin of the earthworm vcp genes, and to provide tools for further detailed genetic and physiological analyses, a Bacterial Artificial Chromosome (BAC) library was established, and the clones carrying the entire evcp-1 and evcp-2 genes were isolated. Genomic sequencing revealed that evcp-1 and evcp-2 occupied approximately 16 kb and 18 kb, respectively, and consisted of 14 introns and 15 exons, a number that is similar to mammalian VCPs.