The identification of three novel genes involved in the rapid-growth regulation in a marine diatom, Skeletonema costatum.
In order to understand the molecular mechanism of growth regulation in phytoplankton and to develop novel growth-status indicators, a subtraction cDNA library was constructed by using the mRNA extracted from Skeletonema costatum in the rapid-growth stage (RG stage), and three RG-stage-related cDNA fragments, RG#14, RG#25, and RG#42, were obtained. According to the results of sequence analysis, RG#42 belonged to the MCM2-7 protein family, and the other two fragments, RG#14 and RG#25, were novel molecules. Under continuous illumination, these RG-stage-related mRNA expression levels increased from 100- (RG#14 and RG#42) to 1,000-fold (RG#25) with increasing growth rate. Furthermore, under a diel rhythm of light (light-dark = 12:12 h), the daily mean mRNA abundances of RG#14 and RG#25 in the exponential phase also differed from those in the late-stationary phase. However, such differences between these growth phases were not observed in the mRNA levels of RG#42 and PCNA. This study not only provided a new way to investigate the regulatory mechanisms of cell growth but also offered a possibility of employing these gene fragments as indicators to monitor the growth status of phytoplankton in the marine environment.
Center for Marine Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan, Republic of China. chungcc@mail.ntou.edu.tw
Chih-Ching
CC
Chung
Sheng-Ping L
SP
Hwang
Jeng
J
Chang
D001483:Base Sequence; D015152:Blotting, Northern; D017931:DNA Primers / Q000235:genetics; D017377:Diatoms / Q000235:genetics* / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D005796:Genes / Q000235:genetics*; D008969:Molecular Sequence Data; D017440:Photoperiod; D016133:Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D017931:DNA Primers