Localization of Aa-nat mRNA in the rat retina by fluorescence in situ hybridization and laser capture microdissection

Cell Tissue Res. 2004 Feb;315(2):197-201. doi: 10.1007/s00441-003-0822-1. Epub 2003 Nov 14.


Arylalkylamine N-acetyltransferase (AA-NAT) is the key regulatory enzyme in the melatonin biosynthetic pathway. Previous investigations have reported that Aa-nat mRNA in rat is only detected in a sub-population of photoreceptor cells that resemble cones in shape and size. In the present study, we investigated Aa-nat expression in the rat retina by using in situ hybridization and laser capture microdissection combined with the reverse transcription/polymerase chain reaction technique. Our results demonstrate that, contrary to previous reports, Aa-nat transcripts are present not only in the photoreceptor cells, but also in the inner nuclear layer and in the ganglion cell layer. However, the rhythmic expression of Aa-nat mRNA was observed only in photoreceptor cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Arylamine N-Acetyltransferase / genetics
  • Arylamine N-Acetyltransferase / metabolism*
  • In Situ Hybridization
  • Melatonin / metabolism
  • Photoreceptor Cells / cytology
  • Photoreceptor Cells / metabolism*
  • RNA, Messenger / genetics
  • Rats
  • Rats, Wistar
  • Retina / anatomy & histology
  • Retina / metabolism*
  • Retinal Cone Photoreceptor Cells / cytology
  • Retinal Cone Photoreceptor Cells / metabolism*
  • Retinal Ganglion Cells / cytology
  • Retinal Ganglion Cells / metabolism*


  • RNA, Messenger
  • Arylamine N-Acetyltransferase
  • Melatonin