MOLECULAR CHARACTERIZATION OF THE POLLEN-SPECIFIC GENOMIC CLONE NTPG303 AND IN-SITU LOCALIZATION OF EXPRESSION

The localization of transcripts of the pollen-specific gene NTP303 has been determined by means of in situ hybridization in combination with confocal laser scanning microscopy. NTP303 transcripts were first det ectable at the mid-bi-nucleate stage of pollen development and persist ed even after the pollen tube had reached the ovary. The majority of t he NTP303 transcripts were localized in the vegetative cell, and were predominantly present in the apex of the pollen tube. To study the mec hanism of regulation, the genomic clone NTPg303 was isolated and chara cterized. NTPg303 belongs to a gene family of at least five members. N o introns are present in its coding region. Regions matching the polle n-specific PB-element TGTGGTT (Twell et al. 1991) have been found.