Nucleotide sequence of a human gene coding for a polypeptide hormone

In summary, a general approach is presented to purify and sequence DNA fragments of a specific gene starting with a heterogeneous mixture of mRNAs. The methodology has been applied to the determination of the DNA sequence of a portion of the gene for human chorionic somatomammotropin. Most of the possible translation codons of the genetic code were found to be used. Some selectivity in the codon choices was found, and this may be important for RNA or gene regulation or structure. The stop codon UAG was found and a second stop codon in the same reading frame was found nine bases farther down. Finally, a "palindrome" sequence was detected in the 3' noncoding region.