Distribution and developmentally regulated expression of murine polycystin

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder primarily caused by mutations in the PKD1 gene.
• The PKD1 gene encodes polycystin, a large protein with transmembrane domains and adhesive properties.
• Understanding polycystin's function and distribution is crucial for ADPKD research.

Purpose of the Study:

• To investigate the mouse homologue of PKD1 (Pkd1) and its encoded protein, polycystin.
• To determine the subcellular localization and tissue distribution of murine polycystin.
• To correlate polycystin expression patterns with kidney development in mice.

Main Methods:

• Isolation of a cDNA clone for the 3' end of mouse Pkd1.
• Generation of a specific antibody against recombinant murine polycystin.
• Western analysis and immunocytochemistry to detect polycystin's presence, localization, and quantity.

Main Results:

• Murine polycystin is an approximately 400-kDa protein primarily located in membrane fractions.
• Polycystin is expressed in various tissues, including kidney, liver, pancreas, heart, intestine, lung, and brain.
• Renal polycystin expression is highest during fetal and neonatal development, decreasing significantly by the third postnatal week.

Conclusions:

• The temporal expression pattern of polycystin in mouse kidneys aligns with critical periods of tubule differentiation and maturation.
• These findings provide a foundation for studying polycystin's role in kidney development and ADPKD using an animal model.