Differential expression of Brn3 transcription factors in intrinsically photosensitive retinal ganglion cells in mouse
Version of Record online: 6 JAN 2012
Copyright © 2011 Wiley Periodicals, Inc.
Journal of Comparative Neurology
Volume 520, Issue 4, pages 742–755, 1 March 2012
How to Cite
Jain, V., Ravindran, E. and Dhingra, N. K. (2012), Differential expression of Brn3 transcription factors in intrinsically photosensitive retinal ganglion cells in mouse. J. Comp. Neurol., 520: 742–755. doi: 10.1002/cne.22765
- Issue online: 6 JAN 2012
- Version of Record online: 6 JAN 2012
- Accepted manuscript online: 20 SEP 2011 01:54PM EST
- Manuscript Accepted: 7 SEP 2011
- Manuscript Revised: 23 JUN 2011
- Manuscript Received: 29 APR 2011
- Department of Biotechnology, Ministry of Science and Technology, Government of India. Grant Number: BT/PR6410/Med/14/801/2005
- National Brain Research Centre, India
Several subtypes of melanopsin-expressing, intrinsically photosensitive retinal ganglion cells (ipRGCs) have been reported. The M1 type of ipRGCs exhibit distinct properties compared with the remaining (non-M1) cells. They differ not only in their soma size and dendritic arbor, but also in their physiological properties, projection patterns, and functions. However, it is not known how these differences arise. We tested the hypothesis that M1 and non-M1 cells express Brn3 transcription factors differentially. The Brn3 family of class IV POU-domain transcription factors (Brn3a, Brn3b, and Brn3c) is involved in the regulation of differentiation, dendritic stratification, and axonal projection of retinal ganglion cells during development. By using double immunofluorescence for Brn3 transcription factors and melanopsin, and with elaborate morphometric analyses, we show in mouse retina that neither Brn3a nor Brn3c are expressed in ipRGCs. However, Brn3b is expressed in a subset of ipRGCs, particularly those with larger somas and lower melanopsin levels, suggesting that Brn3b is expressed preferentially in the non-M1 cells. By using dendritic stratification to distinguish M1 from non-M1 cells, we found that whereas nearly all non-M1 cells expressed Brn3b, a vast majority of the M1 cells were negative for Brn3b. Interestingly, in the small proportion of the M1 cells that did express Brn3b, the expression level of Brn3b was significantly lower than in the non-M1 cells. These results provide insights about how expression of specific molecules in a ganglion cell could be linked to its role in visual function. J. Comp. Neurol., 2012. © 2011 Wiley Periodicals, Inc.