On the cover: The cover picture is a part of fern gametophyte irradiated with weak (right side) and strong light (left side) and then fixed with glutaraldehyde and stained with DAPI. Note different distributions of nuclei and chloroplasts in both parts.
In this issue Tsuboi et al. (pp. 892-896) studied nuclear movement in fern. Fern gametophytes are very sensitive to light. Almost all steps of early development, such as spore germination, protonema growth, direction of the growth (phototropism), cell division, periods of G1 and G2 phase, plane of cell division etc. are controlled by red/far-red and/or blue light. Nucleus and chloroplast movements are also controlled by light. To perform these photoresponses, the fern Adiantum capillus-veneris has three phytochromes, two phototropins, five cryptochromes, and a very unique photoreceptor, neochrome that is a chimera photoreceptor made of chromophore binding domain of phytochrome and full length of phototropin. Another blue light receptor, ZTL/FKF/LKP is also found in A. capillus-veneris expression sequence tags.
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