PLAC1, an Xq26 gene with placenta-specific expression

Genomics. 2000 Sep 15;68(3):305-12. doi: 10.1006/geno.2000.6302.


A novel human X-linked gene shows placenta-specific expression and has been named PLAC1. The gene maps 65 kb telomeric to HPRT at Xq26 and has been completely sequenced at the cDNA and genomic levels. The mouse orthologue Plac1 maps to the syntenically equivalent region of the mouse X chromosome. In situ hybridization studies with the antisense mRNA during mouse embryogenesis detect Plac1 expression from 7.5 dpc (days postcoitum) to 14.5 dpc in ectoplacental cone, giant cells, and labyrinthine trophoblasts. The putative human and murine PLAC1 proteins are 60% identical and 77% homologous. Both include a signal peptide and a peptide sequence also found in an interaction domain of the ZP3 (zona pellucida 3) protein. These results make PLAC1 a marker for placental development, with a possible role in the establishment of the mother-fetus interface.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Chromosome Mapping
  • Embryonic and Fetal Development
  • Expressed Sequence Tags
  • Gene Expression Regulation, Developmental*
  • Giant Cells / metabolism
  • Humans
  • Mice
  • Molecular Sequence Data
  • Open Reading Frames
  • Placenta / metabolism*
  • Pregnancy Proteins / chemistry
  • Pregnancy Proteins / genetics*
  • RNA, Antisense
  • RNA, Messenger / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transcription, Genetic
  • Trophoblasts / metabolism
  • X Chromosome*


  • PLAC1 protein, human
  • Pregnancy Proteins
  • RNA, Antisense
  • RNA, Messenger