Table 1. Genes and gene candidates identified in the NAISTrap project.

Category	No.	Percentage
NR genes	182	39.0
ESTs	49	10.5
Reverse strands of known genes	23	4.9
Repetitive sequences	38	8.1
Unknown sequences	175	37.5
Total	467	100.0

In the NAISTrap project, discrete 3′ RACE bands were recovered from 75% of the total cellular RNA samples extracted from the ES clones that had been picked up after the RET vector introduction and G418 selection. Of the PCR products obtained, 69% produced “high-quality” DNA sequences. Homology searches were performed by the blastn algorithm with genome information from the public databases, including GenBank (http://www.ncbi.nlm.nih.gov) and Ensembl (http://www.ensembl.org). Identity or similarity extending more than ≈ 100 bp with the probability E value of 10^-20 or less was considered to be significant homology. The results of initial 467 NAISTrap sequences are shown.