One Argonaute family member, Eif2c2 (Ago2), is essential for development and appears not to be involved in DNA methylation

AbstractTo elucidate the epigenetic role of RNAi in mammals, we disrupted the gene for Eif2c2 (Ago2), which works as the sole slicer of RNAi in the Argonaute family. In mice, disruption of Eif2c2 leads to embryonic lethality early in development after the implantation stage. This phenotype is completely different from that in a previous report, but somewhat similar to the disruption of Dicer1, another important component of RNAi. We also show that Eif2c2 is not required for the maintenance of DNA methylation in imprinted genes, centromeric repeats, and Xist. This suggests that developmental defects in the Eif2c2-deficient mouse are caused not at the transcriptional level, but rather at the posttranscriptional level through the miRNA–protein complex

The Development of a Self-rating Questionnaire for Screening Dementia

Few self-rating questionnaires have been developed for use in screening for dementia due to technical difficulties. We were required to develop a self-rating questionnaire for dementia for the first-stage screening of a 1995 dementia prevalence study in the Nagasaki Prefecture. In our pilot study, we drafted a questionnaire of 43 items and applied it to 399 subjects in attendance at educational programs for senior citizens, and residing in institutions for senior citizens and in nursing homes for the aged. 185 subjects (71 males, 114 females ; average age, 77.3 years) successfully completed the questionnaire, including 39 subjects with medically diagnosed dementia. We conducted a discriminant analysis on these subjects\u27 responses to the original 43 items, and extracted 13 items which most contributed to discrimination of dementia. The sensitivity of discrimination by the final questionnaire was 0.82, and the specificity was 0.89. In the prevalence study of dementia in Nagasaki Prefecture, we could re-examine the validity of the questionnaire. The high sensitivity and moderate level of specificity of the questionnaire was considered reasonable for use in screening dementia

Mucus glycoproteins selectively secreted from bacteriocytes in gill filaments of the deep-sea clam Calyptogena okutanii

The deep-sea clam Calyptogena okutanii possesses a large gill containing vertically transmitted symbiotic sul-fur-oxidizing bacteria. It produces large amounts of highly viscoelastic mucus from the gill, which is thought to be a physical and chemical barrier. The mucus collected from the gill was shown to be composed of glycoproteins having the following sugar composition: Man (17.4%), GlcNAc (16.6%), GalNAc (15%), Glc (1.1%), Gal (29.9%), Xyl (3.0%), Fuc (14.4%), and unknown (2.6%), indicating that it contained mucin-like glycoproteins. In a monoclonal antibody li-brary against the gill tissue, we found a monoclonal antibody (mAb), CokG-B3C10, reacting to the mucus. Western blot analysis using the mAb showed that it reacted to several glycoproteins in the mucus from the gill tissue, but not with those of other tissues such as the mantle, foot, and ovary, where mucus production has been reported in bivalves. Fur-ther, immunohistochemical analysis showed the CokG-B3C10 mAb reacting to glycoproteins was detected in the inner area of the gill, which was occupied by many bacteriocytes in the row of gill filaments. Strong mAb signals were found on the outer surface of the bacteriocytes facing the interfilamental space, and in the interfilamental spaces between filaments. Weaker signals were also observed in the bacteriocyte cells. These results indicate that the CokG-B3C10 mAb-binding mucus glycoproteins were produced from cells including bacteriocytes and nonbacteriocyte cells in the inner area of the gill filaments.http://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt09-06_leg1/ehttp://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt10-01/ehttp://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt10-08/