• synapse
• split reads
• RNA-seq
• neurobiology
• bioinformatics
• alternative splicing
• aging
• transcriptome

The aim of my thesis is to determine synaptic splice variants that are expressed in an age-dependent way, which is, as has been discussed in the previous sections, a relevant biological problem. Furthermore, validation of the age-dependent synaptic enrichment of ribosomal subunits and their transcripts has been performed through Western Blot and RT-qPCR. These goals were addressed through the following experiment: synaptic transcripts of mice at three different ages (3 weeks, 5-6 months and 18-19 months) were retrieved for sequencing from cortex-derived synaptosomal fractions, and then sequenced using the Illumina platform.

It was shown that both the somatic enrichment of ribosomal proteins and the synaptic enrichment of the transcripts of ribosomal proteins decreases during aging, an observation that could be explained by synapse-specific translational de-repression of those transcripts during aging.

The study of splice variants was performed using DIEGO and Leafcutter, which both allow the identification of differentially expressed splicing variants without relying on already known gene models and by considering split reads. Several age-regulated transcript isoforms were detected using DIEGO and LeafCutter and then validated through RT-qPCR and PCR.