High expression of alternative transcript of granzyme M in the mouse retina

We have isolated cDNAs to two transcripts, granzyme M and alternative granz yme M mRNA from the mouse eye. Analysis of genomic DNA revealed these trans cripts were derived from alternative transcription initiations. Northern bl ot analysis and reverse transcription-polymerase chain reactions revealed t hat both transcripts were expressed in the eye, though the alternative form was the major type. In situ hybridization studies demonstrated that altern ative granzyme hi mRNA localized exclusively in the photoreceptor cells in the retina and expressed only after the Opening of the eye, suggesting that these transcripts are related to the maintenance of the retinal structure or functions of matured photoreceptor cells rather than the development or differentiation of retinal cells. (C) 1999 Elsevier Science Ireland Ltd. Al l rights reserved.