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Updated: Sep 23, 2026

The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo
Published on: August 2, 2017
Pregnancy-specific beta 1 glycoprotein mRNA is present in placental as well as non-placental tissues
W Y Chan1, L A Tease, J Borjigin
1Laboratory of Protein Studies, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Six human SP1 clones were isolated from a term placental cDNA library by immunological screening. All six cDNA clones cross-hybridized. However, at least two classes of cDNA could be distinguished, based on the presence or absence of an EcoRI site in the insert. Northern blot analysis of human term placental mRNA with all six cloned inserts demonstrated the presence of two mRNA species of 1.6 and 2.4 kb, respectively. The amino acid sequences of tryptic fragments of pure human SP1 protein were determined for confirmation of the identity of these cDNA clones. Using one of the cloned cDNA as probe, two and ten hybridizing clones were isolated from a human testicular cDNA library and a HeLa cell cDNA library, respectively. Southern blot analysis of these clones showed strong hybridization with the SP1 cDNA probe under high stringency, indicating the presence of highly homologous mRNA species in these tissues.
Six human SP1 clones were isolated from a term placental cDNA library by immunological screening. All six cDNA clones cross-hybridized. However, at least two classes of cDNA could be distinguished, based on the presence or absence of an EcoRI site in the insert. Northern blot analysis of human term placental mRNA with all six cloned inserts demonstrated the presence of two mRNA species of 1.6 and 2.4 kb, respectively. The amino acid sequences of tryptic fragments of pure human SP1 protein were determined for confirmation of the identity of these cDNA clones. Using one of the cloned cDNA as probe, two and ten hybridizing clones were isolated from a human testicular cDNA library and a HeLa cell cDNA library, respectively. Southern blot analysis of these clones showed strong hybridization with the SP1 cDNA probe under high stringency, indicating the presence of highly homologous mRNA species in these tissues.

