Cry j 2 is the major allergenic protein of Cryptomeria japonica pollen. The protein is considered to play important roles both in pollen tube germination and in pollen tube growth because it has pectinase activity. In the present study, we examined the in vivo localization of Cry j 2 and pectins in the pollen tube and the nucellus to clarify the role of the pectinase. Just after pollination, Cry j 2 was localized only in the intine. During pollen tube growth, however, it was distributed within the cytoplasm of the pollen tube, and also in the pollen tube wall, the middle lamella, and in the nucellar cells that came into contact with a pollen tube. De-esterified pectins were localized in nucellar cell walls and methyl-esterified pectins were localized in nucellar cell walls and the middle lamella. Our findings indicate that Cry j 2 is synthesized within the pollen grain and the pollen tube, and that subsequently Cry j 2 is secreted to the nucellus via the pollen tube wall. Furthermore, Cry j 2 degrades pectins of the nucellar cell wall and the middle lamella to facilitate pollen tube growth. The absence of Cry j 2 in the pollen tube wall in vitro also indicates that interaction between the pollen tube and the nucellus is necessary to induce the secretion of Cry j 2.

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The ontogenetic development of pollen tetrads in Vaccinium smallii was investigated by light and transmission electron microscopy with special attention to the mode of exine deposition. The deposition of the primexine matrix represented by a fibrillar surface coat started during the cytokinesis of the microspore mother cell within a thick callose wall. The deposition of dark lipoidal globules of sporopollenin precursor substances was observed within the primexine matrix. After the disappearance of these globules, radially directed pro-columellae appeared within the primexine matrix, and the primexine gives rise to the tectum, columellae and foot layer after the callose dissolution. The position of future apertures was observed at a thick zone and/or a thin layer of the primexine matrix. In both regions, the pro-columellae, protectum and foot layer were not formed. Major binding mechanism of the permanent mature pollen tetrads in V. smallii is attributed to 1) the early deposition of the primexine matrix on the microspore mother cell undergoing cytokinesis, and 2) thin and tenuous callose depositions, 3) the common primexine matrix, and 4) the cytoplasmic channels between the adjoining microspores of the meiotic tetrad within a thick callose wall.

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Many pollen researchers came to Japan to participate in the joint conferences of the International Palynological Congress (IPC) and the International Palaeobotanical Congress (IPC / IOPC 2012)). The conference was a very fruitful meeting. From South Korea, there were reports of Japanese cedar (Cryptomeria japonica) pollen becoming a significant allergen in Korea. In Europe recent achievements of HIALINE (Health Impact of Airborne Allergen Network) research projects were reported. And, from Japan, the value of male sterility data for C. japonica was discussed as a tool for pollen emission prevention from Japanese artificial forests. The potential significance of an automated pollen monitor for forecasting pollen scattering of C. japonica was also reported. The international meeting was very friendly and gave ample opportunity to discuss future international collaborative research. We noted, however, that there are very few departments in Japanese universities and institutes majoring in aerobiology. Aerobiological studies provide not only a public pollen information service, but also supply information to medicine, pharmacy, public health, forestry, engineering and environmental science with, not only an accumulation of past data but also, based on these data, the building of predictive models. We sincerely hope that the success of this international joint meeting in Japan has, and will provide, the opportunity for both professionals and the general public to learn more about aerobiology, palynology and related academic fields in a worldwide context.

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An investigative survey of medication and lifestyle differences between patients suffering from Cryptomeria japonica (Japanese Cedar) pollinosis was carried out. Of the 137 patients who responded to the questionnaire, there were 94 patients affected by Japanese Cedar pollinosis, and 32 (34.0%) patients who do not have atopic dermatitis, but complained of skin symptoms related to Japanese Cedar pollinosis. Almost all of the patients in our study had spent time outdoors during the period of pollen dispersal, the pollinosis rates for those wearing special protective glasses were low. It is important to note that almost all of the patients who normally wear contact lenses, where also wearing their contact lenses outside during the pollen season. About 88.3% of the patients received and followed information about pollinosis from the mass media, such as television, and of these patients 71.2% of those who received and answered the questionnaire said that the information about pollen was useful.In the section of the questionnaire relating to oral medicine, about 93.6% of the patients had taken it correctly. However, adherence to guidelines, and use of medicine for external application, was poorly carried out by patients. In addition, it was noticed that 26% of the patients, for whom medicine was prescribed by a doctor, had actually purchased over the counter (OTC) medication.

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