The vertebrae are patterned by the Hox complex of transcription factors,which are expressed in nested domains along the cranial-caudal axis.Hox gene expression is regulated by retinoic acid.How would gain of retinoic acid function be expected to affect the developing vertebrae?

Question

Quizplus · Accepted Answer

Retinoic acid activates Hox genes in a differential way along the cranial-caudal axis. With an increased dosage of retinoic acid, the anterior-posterior patterning of the developing vertebrae is disrupted resulting in caudalization, leading to the formation of additional caudal vertebrae at the expense of cranial vertebrae. Therefore, gain of retinoic acid function would caudalize the developing vertebrae.

The Vertebrae Are Patterned by the Hox Complex of Transcription