Gametic differentiation inChlamydomonas reinhardtii: light dependence and gene expression patterns

✍ Scribed by Ulrike Treier; Sabine Fuchs; Martina Weber; Warren W. Wakarchuk; Christoph F. Beck

• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 772 KB
• Volume: 152
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00425489

✦ Synopsis

Gametes of Chlamydomonas reinhardtii synthesize numerous proteins not observed in vegetative cells and vice versa. Gametogenesis induced changes in gene expression were confirmed by SDS-PAGE of in vitro translation products using total RNA from gametes and vegetative cells. Vegetative cells and gametes thus represent two cell types with distinct patterns of gene expression. The generation of mature gametes from liquid cultures of asynchronously growing vegetative cells was dependent on light. This light requirement could not be substituted for by an organic source of energy and carbon, indicating that light serves as a signal in gametogenesis. The light signal was shown to become effective only after preincubation in nitrogen-free medium. This delayed competence for light indicates that the two external signals -nitrogen-starvation and lightmay function in sequence. Execution of the light dependent step in gamete formation required cytoplasmic protein synthesis and RNA synthesis.