Biparental alleles of HLA-G are co-dominantly expressed in the placenta.
HLA-G is the only major histocompatibility complex molecule expressed in the human placenta and thus has been considered to be necessary for maintenance of pregnancy. We investigated whether HLA-G expression is regulated in a parent-of-origin allele-specific manner. Of six first trimester and three third trimester placentas, three first trimester and two third trimester placentas showed heterozygosity at the PstI polymorphic site in the 3'-untraslated region. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed biallelic expression of HLA-G in all the informative cases, indicating that HLA-G is not imprinted during the gestational period, at least at the transcriptional level. As HLA-G has been postulated to be polymorphic not only at the DNA sequence level but also at the peptide level, co-dominant expression of the gene suggests that each parental allele is involved in the allogenic response during pregnancy.
Hashimoto
K
K
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Azuma
C
C
Koyama
M
M
Nobunaga
T
T
Kimura
T
T
Shimoya
K
K
Kubota
Y
Y
Saji
F
F
Murata
Y
Y
D000483:Alleles; D005260:Female; D015870:Gene Expression / Q000235:genetics / Q000502:physiology; D005799:Genes, Dominant / Q000235:genetics / Q000502:physiology; D018392:Genomic Imprinting / Q000235:genetics / Q000502:physiology; D006680:HLA Antigens / Q000235:genetics*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011263:Pregnancy Trimester, Third
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I