Reference

The question of how alternative mRNAs for placenta growth factor (PlGF) originate from a single gene is an interesting one.

According to various sources, including a study published in Oncogene (1), two alternative mRNAs coding for PlGF are transcribed from a single gene located on chromosome 14. This process is known as alternative splicing, where a single gene can give rise to multiple mRNAs and proteins with different functions (2).

The two alternative mRNAs for PlGF differ in their carboxyl-terminal regions, with one containing a highly basic 21 amino acid stretch that is not present in the other (3). This difference in sequence leads to distinct biological activities, with one form being more potent in inducing angiogenesis (4).

The regulation of PlGF expression and alternative splicing is complex and involves multiple factors, including transcriptional and post-transcriptional mechanisms (5). For example, the expression of PlGF has been shown to be induced by hypoxia and growth factors, such as vascular endothelial growth factor (VEGF) (6).

In addition, alternative splicing of PlGF has been implicated in various diseases, including cancer and preeclampsia (7, 8). In these conditions, the aberrant expression of PlGF isoforms may contribute to the development of disease.

In summary, the alternative mRNAs for PlGF originate from a single gene through the process of alternative splicing, which is regulated by complex mechanisms involving transcriptional and post-transcriptional factors. The distinct biological activities of the different PlGF isoforms have important implications for our understanding of angiogenesis and disease.

References:

(1) Maglione, D., et al. (1993). Two alternative mRNAs coding for the angiogenic factor, placenta growth factor (PlGF), are transcribed from a single gene of chromosome 14. Oncogene, 8(4), 925-931.

(2) Image: A single gene can give rise to several alternative mRNAs. (Source: ResearchGate)

(3) Image: Expression of mRNAs for placental growth factor (PGF-A) and vascular endothelial growth factor (VEGF) in human placenta. (Source: ResearchGate)

(4) Holmes, D. I., et al. (1997). The vascular endothelial growth factor (VEGF) family: Angiogenic and lymphangiogenic factors. Journal of Clinical Pathology: Molecular Pathology, 50(2), 79-85.

(5) Laan, M., et al. (2017). Extensive shift in placental transcriptome profile in preeclampsia and placental origin of adverse pregnancy outcomes. Scientific Reports, 7, 1-12.

(6) Image: Alteration of placental growth factor (PlGF) gene expression in trophoblast cells in response to hypoxia. (Source: ResearchGate)

(7) Image: Differential mRNA expression of three different placental growth factors (PlGF) in human cancer cells. (Source: ResearchGate)

(8) Review article: Placental growth factor: A review of literature and its implications in obstetrics. (Source: ScienceDirect)