A novel vector for transgenesis in the rat CNS

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Rats offer a more complex behavioral repertoire than mice, making them ideal for neurodegeneration research.
• Limited molecular tools for specific transgene expression in rat brains hinder research progress.

Purpose of the Study:

• To develop a novel vector for driving transgene expression in the rat brain.
• To validate the vector's efficacy and specificity for neurodegeneration studies.

Main Methods:

• Compared rat, mouse, and hamster Prnp sequences to identify conserved genetic elements.
• Generated a novel vector, RaPrnp, by modifying the rat Prnp gene, including replacing the open reading frame (ORF).
• Validated in vivo neuronal specificity using RaPrnp-LacZ/EGFP transgenic rats and assessed scrapie onset in Prnp-overexpressing rats.

Main Results:

• The RaPrnp vector demonstrated robust LacZ activity and EGFP fluorescence in the rat central nervous system.
• Overexpression of prion protein (PrP) in transgenic rats accelerated scrapie onset.
• Tg2922 rats, with 9.7-fold PrP overexpression, showed significantly reduced incubation times (112 dpi) and distinct vacuolation patterns compared to wild-type rats.

Conclusions:

• The novel RaPrnp vector enables specific transgene expression in the rat brain.
• Transgenic rats with modified Prnp phenotypes are valuable models for studying neurodegenerative diseases like scrapie.
• Rats may offer advantages over mice for complex neurodegeneration research due to their enhanced cognitive abilities and the developed vector system.