Patent ID: 7728118

Claim:
An isolated nucleic acid molecule comprising a synthetic nucleotide sequence having a coding region for a selectable polypeptide, wherein the synthetic nucleotide sequence has 90% or less nucleic acid sequence identity to a wild-type or parent nucleic acid sequence encoding a corresponding selectable polypeptide which, when expressed in a cell, confers resistance to puromycin, hygromycin-or neomycin, wherein the decreased sequence identity is a result of different codons in the synthetic nucleotide sequence relative to the codons in the wild-type or parent nucleic acid sequence, wherein the synthetic nucleotide sequence encodes a selectable polypeptide with at least 85% amino acid sequence identity to the corresponding selectable polypeptide encoded by the wild-type or parent nucleic acid sequence, wherein the synthetic nucleotide sequence has a reduced number of regulatory sequences including a reduced number of a combination of different vertebrate transcription factor binding sequences and of promoter modules relative to the number of regulatory sequences in a derivative of the wild-type or parent nucleic acid sequence in which native codons are replaced with high usage mammalian codons, as a result of selecting mammalian codons as the different codons so as to reduce the number of regulatory sequences, and wherein the synthetic nucleotide sequence, when expressed in a cell, confers resistance to puromycin, hygromycin or neomycin, wherein the synthetic nucleotide sequence has at least 90% or more nucleic acid sequence identity to SEQ ID NO:11, SEQ ID NO:71 or SEQ ID NO:73, or the complete complement thereof.