Different combinations of regulatory elements may account for expression of the glycoprotein hormone alpha-subunit gene in primate and horse placenta.
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.
Fenstermaker
R A
RA
Department of Pharmacology, Western Reserve University School of Medicine, Cleveland, Ohio 44106.
Farmerie
T A
TA
Clay
C M
CM
Hamernik
D L
DL
Nilson
J H
JH
D000818:Animals; D001483:Base Sequence; D000242:Cyclic AMP / Q000494:pharmacology; D005260:Female; D015870:Gene Expression; D015292:Glycoprotein Hormones, alpha Subunit / Q000235:genetics*; D006071:Gorilla gorilla / Q000235:genetics; D006736:Horses / Q000235:genetics*; D006801:Humans; D008253:Macaca mulatta / Q000235:genetics; D008969:Molecular Sequence Data; D002679:Pan troglodytes / Q000235:genetics; D010215:Papio / Q000235:genetics; D010920:Placenta / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011401:Promoter Regions, Genetic / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D015292:Glycoprotein Hormones, alpha Subunit; D000242:Cyclic AMP