Over expression of PQQ glucose dehydrogenase in Escherichia coli under holo enzyme forming condition

Summary The over expression of PQQ glucose dehydrogenase PQQGDH was investigated. The level of PQQGDH expressed in E.coli PP2418/pGEc1 was more than 10 fold when the cultivation was carried out under holo enzyme forming condition in the presence of 600 nM of PQQ and 10 mM of MgCl₂, compared with those of apo condition. It may be due to the difference in thermal stability of apo and holo PQQGDH.     

Chimeric analysis of EGFP and DsRed2 transgenic mice demonstrates polyclonal maintenance of pancreatic acini

The pancreatic islet is an assembly of specific endocrine cells. There are many conflicting reports regarding whether the acinus develops from single or multiple progenitor cells. This study investigated the development and maintenance clonality of the pancreatic acinus and duct using a chimeric analysis with EGFP and DsRed2 transgenic mice. Chimeric mice (G-R mice) were obtained by the aggregation method, using 8-cell stage embryos from EGFP and DsRed2 transgenic mice. The islets from the G-R mice were chimeric and mosaic, consisting of either EGFP- or DsRed2-positive populations, as in previous reports. On the other hand, most acini developed from either EGFP or DsRed2 origin, but some were chimeric. Interestingly, these chimeric acini were clearly separated into two-color regions and were not mosaic. Some large intralobular pancreatic ducts consisting of more than 10 cells were found to be chimeric, but no small ducts made up of less than 9 cells were chimeric. Our histological observations suggest that the pancreatic acinus polyclonally and directionally is maintained by multiple progenitor cells. Pancreatic large ducts also seem to develop polyclonally and might result from the assembly of small ducts that develop from a single origin. These findings provide useful information for further understanding pancreatic maintenance.     

Exploring community assembly among Javanese and Balinese freshwater shrimps (Atyidae,Palaemonidae) through DNA barcodes

Hydrobiologia - Species proliferate through evolutionary mechanisms but coexist through ecological dynamics. As such, it might be expected that mechanisms of speciation and species maintenance...