Porcine granulosa cells do not express transforming growth factor-beta 2 (TGF-beta 2) messenger ribonucleic acid: molecular basis for their inability to produce TGF-beta activity comparable to that of rat granulosa cells

Endocrinology. 1992 Dec;131(6):2609-14. doi: 10.1210/endo.131.6.1280203.


In contrast to rat granulosa cells (GC), GC of the pig and cow produce very low levels of transforming growth factor-beta (TGF-beta)-like activity in vitro. Because cultured rat GC predominantly express TGF-beta 2 messenger RNA (mRNA) and secrete high levels of the protein, we hypothesized that TGF-beta 2 mRNA expression by porcine GC might be absent or diminished, thus providing a molecular explanation(s) for their relatively low levels of TGF-beta production. We tested this hypothesis by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay analysis. When analyzed by RT-PCR, porcine GC RNA from 1-3 mm follicles did not yield the expected 489 base pair (bp) TGF-beta 2 product but instead generated a smaller than anticipated 240 bp species; porcine testis RNA generated both the 240 and the anticipated 489 bp products. Sequencing these species indicated that the smaller form was not a novel TGF-beta 2 splice variant, and that the 489-bp product was porcine TGF-beta 2. This is the first reported nucleotide sequence for porcine TGF-beta 2; it is 90% and 91% identical to murine and human TGF-beta 2 sequences, respectively. Further RT-PCR analysis of porcine GC RNA resulted in the identification of bp products representing TGF-beta 1 and TGF-beta 3 mRNA. Enzyme-linked immunosorbent assay analysis of porcine GC conditioned medium confirmed the presence of TGF-beta 1 at very low levels. TGF-beta 2 was undetectable. Comparable analysis of GC from the diethylstilbestrol-treated prepubertal rat demonstrated the presence of TGF-beta 1 and TGF-beta 3 mRNA by RT-PCR and very low levels of the corresponding protein products in conditioned culture medium. Collectively, these results suggest that the inability of porcine GC to express TGF-beta 2 mRNA could explain the very low levels of TGF-beta activity secreted by these cells in vitro.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Cattle
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Gene Expression*
  • Granulosa Cells / metabolism*
  • Immunologic Techniques
  • Male
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism*
  • RNA-Directed DNA Polymerase
  • Rats
  • Swine
  • Testis / metabolism
  • Transforming Growth Factor beta / analysis
  • Transforming Growth Factor beta / biosynthesis
  • Transforming Growth Factor beta / genetics*


  • RNA, Messenger
  • Transforming Growth Factor beta
  • RNA-Directed DNA Polymerase

Associated data

  • GENBANK/D13201
  • GENBANK/D13202
  • GENBANK/D13203
  • GENBANK/M94783
  • GENBANK/M94784
  • GENBANK/M94785
  • GENBANK/X64300
  • GENBANK/X70142
  • GENBANK/Z13994
  • GENBANK/Z14001