Transcriptomic Analysis of Taar5 Expression and Co-Expression Networks in the Cerebellum During Perinatal Development

Background: Dopamine participates in the cognitive cerebellar role and in cerebellum development. The trace amine-associated receptor (TAARs, TAAR1-TAAR9) system contributes to dopamine signaling tuning. So, the aim of the present study is the analysis of the TAARs' gene expression and functional associations in prenatal and neonatal mouse cerebellums. Methods: The transcriptomic data represented in the GEO repository was performed to identify Taars expression and co-expression patterns in embrionic and postnatal mouse cerebellum. Results: Open transcriptomic data analysis showed cerebellar expression of the Taar5 gene mRNA both in prenatal and early postnatal samples. The identified Taar5 expression was confirmed by RT-PCR in P5 mice. We identified the association between Taar5 expression and the expression of proliferation-related genes in late prenatal E13.5 samples, which was replaced by co-expression with genes involved in metabolism in P5-6 samples. These associations are suggested to mirror the previously identified Taar5 expression in Purkinje cells, which proliferate at the E13.5 and mature in the postnatal period. However, the analysis of TAAR5 co-expression with markers of different cell populations revealed the pronounced co-expression of TAAR5 in the P5-6 cerebellum with microglial markers, which is shifted to the association with astroglial markers in P10. Conclusions: The Taar5 gene was found to be active in the cerebellum samples taken around birth, and its co-expression pattern differs in the embryo stage and the early days after birth. We suggest that the Taar5 receptor may be involved in cerebellum development; however, further research is necessary to elucidate its role in this process.