Reticulons (RTN) are endoplasmic reticulum- associated protein complexes, which are localized in the endoplasmic reticulum (ER) and identified as markers for neuroendocrine differentiation. At least four different RTN genes have been identified in mammals, but in most cases, the functions of the encoded proteins except mammalian RTN4-A and RTN4-B are still elusive. In the present study, mouse reticulon 3 (mRTN3) is cloned and its expression pattern in a variety of tissues is investigated. Three alternatively spliced transcripts of 1.8, 2.8 and 4.2 kb are revealed by Northern blotting hybridization. The 1.8 and 2.8 kb transcripts are expressed in many tissues. The 2.8 kb transcript has a high level in brain and the 4.2 kb transcript is only found in brain. In situ hybridization and immunohistochemical analysis indicated its high expression in non-glial cells in some particular region of mouse central nervous system, such as hippocampus, sub-thalamus nucleus, thalamus nucleus and cerebrum cortex.
