Involvement of L1 retrotransposition in midbrain dopaminergic neurons and schizophrenia.
Final Report Abstract
The results address Aim1 and 2, and are the basis of more experiments. I have showed that L1 ORFs proteins necessary for L1 mobilization are expressed in dopaminergic neurons. Further, L1 copy number analysis in microdissected SN versus VTA neurons suggested that L1 activity is different in the two dopaminergic subpopulations. Currently, I am investigating whether this holds true by assessing L1 mRNA expression and RCseq in laser microdissected SN versus VTA. Behavioral tests in Poly I:C mice confirmed that this is a valid model to study changes related to schizophrenia which I can quantify with the current set-up. I have succeeded in generating L1-EGFP mice, currently crossing them with Dat-Cre x R26Ai14 to asses changes L1 retrotransposition in dopaminergic neurons upon PolyI:C treatment. The behavioral consequences of L1 hyperactivation on SZ phenotypes will be performed within the following year and will complete Aim3. RCseq applied to a set of human parietal cortex samples in SZ and controls suggested that only polymorphic insertions could be detected and validated in bulk tissue. These insertions might still be of interest but to understand their role in neuronal function and disease, a new approach has to be undertaken. Studying these insertions in SZ mice, as opposed to postmortem human samples, will allow for detecting and tracking germline or early developmental heritable insertions. A single cell RCseq strategy will be better suited to identify and validate somatic insertions. Currently, an improved single cell RCseq method is being developed in the lab and I can benefit from using this method to identify somatic insertions in prefrontal cortices of SZ and controls.
