Different combinations of regulatory elements may account for expression of the glycoprotein hormone alpha-subunit gene in primate and horse placenta

Mol Endocrinol. 1990 Oct;4(10):1480-7. doi: 10.1210/mend-4-10-1480.


Expression of the glycoprotein hormone alpha-subunit gene occurs in the pituitaries of all mammals and in the placentas of primates and horses. In humans, tandem cAMP response elements (CREs), located in the proximal promoter-regulatory region of the alpha-subunit gene, act together with an adjacent upstream regulatory element to confer placenta-specific expression. Here, we report that the alpha-subunit genes of Old World Monkeys contain a single functional CRE. This suggests that tandem CREs are unique to higher primates and humans and are not absolutely required for placenta-specific expression. In contrast, the comparable promoter-regulatory region of the horse alpha-subunit gene lacks a functional CRE but appears to retain a functional upstream regulatory element. This suggests that acquisition of placenta-specific expression of the alpha-subunit gene occurred independently in these distantly related mammals. As a result, different combinations of cis-acting elements may explain why expression of the alpha-subunit gene only occurs in placenta of primates and horses.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Cyclic AMP / pharmacology
  • Female
  • Gene Expression*
  • Glycoprotein Hormones, alpha Subunit / genetics*
  • Gorilla gorilla / genetics
  • Horses / genetics*
  • Humans
  • Macaca mulatta / genetics
  • Molecular Sequence Data
  • Pan troglodytes / genetics
  • Papio / genetics
  • Placenta / metabolism*
  • Polymerase Chain Reaction
  • Pregnancy
  • Promoter Regions, Genetic / genetics
  • Regulatory Sequences, Nucleic Acid*
  • Sequence Homology, Nucleic Acid
  • Transfection


  • Glycoprotein Hormones, alpha Subunit
  • Cyclic AMP