The mouse Trm1-like gene is expressed in neural tissues and plays a role in motor coordination and exploratory behaviour

Using a gene trap approach in ES cells, the novel mouse gene Trm1-like with substantial sequence homology to human C1orf25 mRNA (GenBank accession no. AF288399) was identified. Murine Trm1-like encodes a putative protein with limited similarity to N2, N2-dimethylguanosine tRNA methyltransferase ( Trm1) from other organisms, however its function is not known. The potential role of Trm1-like was investigated in a mouse mutant lacking intact Trm1-like transcripts due to integration of the gene trap vector in the first intron. Trm1-like deficient mice are viable and show no apparent anatomical defects. Behavioural tests, however, revealed significantly altered motor coordination and aberrant exploratory behaviour. LacZ activity of the trapped mouse Trm1-like gene reflects expression in various neuronal structures during embryonic development, including spinal ganglia, trigeminal nerve and ganglion, olfactory and nasopharyngeal epithelium, and nuclei of the metencephalon, thalamus and medulla oblongata. The gene is also expressed in lung, oesophagus, epiglottis, ependyma, vertebral column, spinal cord, and brown adipose tissue. Trm1- like expression persists in the adult brain with dynamically changing patterns in cortex and cerebellum. Although Trm1- like is not essential for embryonic mouse development, it may have a role in modulating postnatal neuronal functions.