Growth factor receptor messenger RNA expression in human fetal brain regions

To analyze growth factor receptor expression in the human fetal brain.

Messenger RNA was prepared from six regions of the fetal brain from three 21-22-week abortuses and used as templates for reverse transcription. Polymerase chain reaction (PCR) was used to amplify the complementary DNA for each of the six brain regions. Amplified PCR DNA fragments were analyzed by agarose gel electrophoresis. Restriction endonuclease digestion was used to confirm the identity of the amplified PCR fragments.

Polymerase chain reaction amplified DNA fragments consistent with expression of the insulin, insulin-like growth factors I and II, fibroblast growth factor (FGF), transforming growth factor-beta, and epidermal growth factor receptors were detected in each area of the human fetal brain studied. Of the two known insulin receptor subtype sequences, only the smaller (exon 11-) form was detected. We detected both the intact and the 267 base-deleted alternatively spliced forms of the FGF receptor.

All six of the receptor messenger RNAs studied were detected in the second-trimester human fetal brain. In addition, alternative splicing of the messenger RNA was noted for the FGF and insulin receptors. This report demonstrates growth factor receptor expression and alternate splicing in specific regions of the human fetal brain. These data suggest that growth factor influence on fetal brain development may be mediated through specific growth factor receptors.