Detection and partial sequence analysis of gastrin mRNA by using an oligodeoxynucleotide probe

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Gastrin is a key hormone involved in regulating gastric acid secretion.
• Understanding gastrin gene expression is crucial for studying gastrointestinal physiology and pathology.

Purpose of the Study:

• To develop a method for detecting and characterizing gastrin mRNA using a specific deoxyoligonucleotide probe.
• To determine the sequence and size of gastrin mRNA and estimate the size of its precursor peptide.

Main Methods:

• Synthesis of a deoxyoligonucleotide probe based on the amino acid sequence of gastrin.
• Using the probe as a primer for complementary DNA (cDNA) synthesis from hog antrum RNA.
• Nucleotide sequencing of synthesized cDNA and Northern blot analysis of gastrin mRNA.

Main Results:

• An 81-nucleotide sequence of gastrin mRNA was determined, coding for the G34 progastrin intermediate.
• Two consecutive basic residues were identified preceding the G34 sequence in the prohormone.
• Gastrin mRNA was found to be approximately 620 nucleotides long, suggesting a precursor peptide of 110-140 amino acids.

Conclusions:

• The deoxyoligonucleotide probe is effective for detecting and characterizing gastrin mRNA.
• The study provides insights into the structure of the gastrin precursor peptide.
• This method has general applicability for mRNA detection of proteins with known amino acid sequences.