Workflow of cDNA library construction. A mixed-stage regeneration/fission cDNA library was generated from ~4,500 P. leidyi worms. Anteriorly and posteriorly regenerating worms were collected from 0 to 3.5 days after amputation (dotted lines mark amputation planes; gray terminal masses represent regeneration blastemas) and actively fissioning worms were also collected (gray shading marks intercalated head and tail tissue that forms during fission). Following RNA extraction and cDNA synthesis, a portion of the pooled cDNA was normalized. The final library sent for 454 sequencing consisted of 2/3 normalized and 1/3 non-normalized cDNA.
Nyberg et al. BMC Genomics 2012 13:287 doi:10.1186/1471-2164-13-287