You are studying the effects of exposure of mouse embryos to various concentration of retinoic acid. Your studies show that the developmental malformations you observe are due to retinoic acid-induced changes in the expression of several homeobox (HOX) genes. Both retinoic acid receptors and HOX gene products recognize and bind to specific DNA sequences at numerous sites on multiple chromosomes. Which of the following best describes the function of these molecules?
A) initiation factors
B) ligands
C) polymerases
D) signal recognition particles
E) transcription factors

Question

Quizplus · Accepted Answer

Retinoic acid receptors and HOX gene products function as transcription factors, which bind to specific DNA sequences to regulate gene expression.  Retinoic acid binds to a family of nuclear receptors called the retinoic acid receptors (RARs). Like all nuclear receptors, the RARs are ligandand DNA-binding transcription factors. All of the proteins encoded by the HOX genes are also transcription factors that contain a DNA-binding domain and function by binding to specific target genes and regulating their rate of transcription.

You Are Studying the Effects of Exposure of Mouse Embryos