The present invention is based on the discovery that the transcriptional activity of both hamster mammary tumor 7 (HMT-7) and hamster layilin genes are increased when Chinese Hamster Ovary (CHO) cells are cultured at temperatures lower than 37.degree. C. The present invention provides novel genomic, cDNA, and protein sequences of HMT-7 and a novel genomic sequence for hamster layilin. Included in the genomic sequences are novel temperature-induced promoter sequences for each; two promoter sequences are provided for HMT-7 and one promoter sequence is provided for layilin. The invention additionally provides antisense and siRNA molecules to the nucleic acid molecules of HMT-7. The invention also provides genetically engineered expression vectors comprising the novel temperature-induced promoters of the invention, which are particularly useful as part of a mammalian temperature-inducible expression system. The invention also provides host cells and/or transgenic animals comprising the novel nucleic acid molecules of the invention. The invention further provides methods of using the polynucleotides of the invention, e.g., for temperature-induced transgene expression.