CPM Is a Useful Cell Surface Marker to Isolate Expandable Bi-Potential Liver Progenitor Cells Derived from Human iPS Cells

To develop a culture system for large-scale production of mature hepatocytes, liver progenitor cells (LPCs) with a high proliferation potential would be advantageous. We have found that carboxypeptidase M (CPM) is highly expressed in embryonic LPCs, hepatoblasts, while its expression is decreased along with hepatic maturation. Consistently, CPM expression was transiently induced during hepatic specification from human-induced pluripotent stem cells (hiPSCs). CPM+ cells isolated from differentiated hiPSCs at the immature hepatocyte stage proliferated extensively in vitro and expressed a set of genes that were typical of hepatoblasts. Moreover, the CPM+ cells exhibited a mature hepatocyte phenotype after induction of hepatic maturation and also underwent cholangiocytic differentiation in a three-dimensional culture system. These results indicated that hiPSC-derived CPM+ cells share the characteristics of LPCs, with the potential to proliferate and differentiate bi-directionally. Thus, CPM is a useful marker for isolating hiPSC-derived LPCs, which allows development of a large-scale culture system for producing hepatocytes and cholangiocytes

Oryzalin-induced Allotetraploids of and Intersubgeneric Hybrid between Evergreen and Deciduous Azaleas

Pollen viability of intersubgenetic hybrids between evergreen and deciduous azaleas was much lower than that of their parents. No capsule set in the crossings with the hybrids when used either as seed or pollen parents. In vitro chromosome doubling with oryzalin was attemped for restoring the fertility of the hybrid. Survival rates of the explants were more than 50% in oryzalin treatments, though high concentration and long term treatments brought the survival rates and number of shoots per explant low, under which number of shoots per explant also decreased. Twenty tetraploid and 28 mixploid (2x+4x) plants were obtained by the treatments from 123 individuals. The most suitable conditions for obtaining tetraploids appared to be 0.01% oryzalin treatment for 48 hours

Homogeneous triploid and tetraploid production through crossing with mixoploid parents in pointed gourd (Trichosanthes dioica Roxb.)

This paper elucidates a procedure for isolating homogeneous triploid and tetraploid progeny from mixoploids, which are the most desirable genetic resources to develop genetically stable seedless variety in pointed gourd (Trichosanthes dioica Roxb.) as seeds are unpalatable. All the colchicine concentrations (0.05, 0.1, 0.5%) effectively led to the production of mixoploid for 48 and 72 h exposure time whereas 24 h did not response to induce mixoploid. These mixoploids (female and male) exhibit cross compatability with diploid (female and male) parents for F1 seed generation. Interestingly, mixoploid parents (either female or male) produced a mixture of normal diploid size seeds and some abnormally large ones, almost twice normal size. Density plot and principal component analysis (PCA) of 603 seeds resulted in separation of diploid, mixoploid and tetraploid accessions involved in different ploidy crosses. To develop a method for the isolation of sexually derived triploid and tetraploid progeny from the induced mixoploids, we examined the ploidy level of F1 populations by flow cytometry where 18.7% F1 seedlings were confirmed as triploid and tetraploid progeny when female mixoploid crossed with male mixoploid while 16.7% triploids were isolated crossed with male diploid. These findings suggest that mixoploid female parents were the best options for developing triploid and tetraploid progeny. Overall, the results of this study provide a framework to explore the genetic basis of polyploids isolated from colchicine induced mixoploids in in vivo conditions