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/

Report: Monoclonal antibodies that recognize symbiotic bacteria and hemocytes in the deep-sea vesicomyid clam Phreagena okutanii

Vesicomyid clams, including the genus Phreagena, are dominant members of various deep-sea chemosynthesisbased animal communities. They harbor symbiotic sulfur-oxidizing bacteria in the epithelial cells of their gill tissue, and the bacteria are transmitted to the next generations via eggs. We created a monoclonal antibody (mAb) library against the gill of P. okutanii and observed mAb CokG-D1D3 to react to the symbiotic bacteria and three mAbs (CokG-Y1F7, CokG-J10D2, and CokG-J3G4) to bind to hemocytes of P. okutanii. The signals of mAb CokG-D1D3 were localized in the epithelial gill cells called bacteriocytes. We also observed a small number of clear signals of the antibody in the epithelial follicular cells of the ovary. The signals of mAb CokG-D1D3 almost exactly overlapped those of the anti-E. coli GroEL polyclonal antibody, while, in the gill, the signal areas of the latter seemed to be slightly wider than those of the former. Among the three mAbs against the hemocytes, mAbs CokG-Y1F7 and CokG-J10D2 reacted to a large fraction of the hemocyte populations, but mAb CokG-J3G4 reacted to a smaller fraction. mAb CokG-Y1F7 was observed to bind to the hemocytes distributed widely in the interstitial spaces of various tissues. These monoclonal antibodies are expected to be useful for studying the interactions between symbiotic bacteria and host cells and the distribution and functions of hemocytes in deep-sea vesicomyid clams

An essential role of the universal polarity protein, aPKClambda, on the maintenance of podocyte slit diaphragms.

Glomerular visceral epithelial cells (podocytes) contain interdigitated processes that form specialized intercellular junctions, termed slit diaphragms, which provide a selective filtration barrier in the renal glomerulus. Analyses of disease-causing mutations in familial nephrotic syndromes and targeted mutagenesis in mice have revealed critical roles of several proteins in the assembly of slit diaphragms. The nephrin-podocin complex is the main constituent of slit diaphragms. However, the molecular mechanisms regulating these proteins to maintain the slit diaphragms are still largely unknown. Here, we demonstrate that the PAR3-atypical protein kinase C (aPKC)-PAR6beta cell polarity proteins co-localize to the slit diaphragms with nephrin. Furthermore, selective depletion of aPKClambda in mouse podocytes results in the disassembly of slit diaphragms, a disturbance in apico-basal cell polarity, and focal segmental glomerulosclerosis (FSGS). The aPKC-PAR3 complex associates with the nephrin-podocin complex in podocytes through direct interaction between PAR3 and nephrin, and the kinase activity of aPKC is required for the appropriate distribution of nephrin and podocin in podocytes. These observations not only establish a critical function of the polarity proteins in the maintenance of slit diaphragms, but also imply their potential involvement in renal failure in FSGS

Monoclonal antibodies that recognize symbiotic bacteria and hemocytes in the deep-sea vesicomyid clam Phreagena okutanii

http://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt09-06_leg1/ehttp://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt10-08/ehttp://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt11-09/ehttp://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt13-07/ehttp://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr12-05/