Analysis of Expressed Sequence Tags Derived from Developing Seed and Pollen Cones of Cryptomeria japonica

Abstract: We obtained 1210 expressed sequence tags (ESTs), representing 1173 transcripts, from two cDNA libraries, which derive from developing seed and pollen cones of sugi (Cryptomeria japonica). Among these 1173 transcripts, 807 showed notable similarity to known sequences, including those of genes expressed in developing flower tissues of other plant species, such as CONSTANS and the genes for MADS‐domain proteins. This result indicates that, in spite of differences in morphology, the development of reproductive organs is regulated by a family of homologous transcription factors common to both gymnosperm and angiosperm species. The remaining 366 transcripts showed no significant similarity to any known sequences in public databases. Furthermore, we compared the 1173 transcripts to those derived from other tissues of C. japonica to investigate the possibility of tissue‐specific transcripts, and found that 882 did not occur among ESTs derived from other tissues, such as the inner bark and seedlings. The ESTs developed during the present study most likely include tissue‐ and stage‐specific transcripts, and these will contribute to a further understanding of the reproductive organ development of C. japonica.