FGF2 Has Distinct Molecular Functions from GDNF in the Mouse Germline Niche

Both glial cell line-derived neurotrophic factor (GDNF) and fibroblast growth factor 2 (FGF2) are bona fide self-renewal factors for spermatogonial stem cells, whereas retinoic acid (RA) induces spermatogonial differentiation. In this study, we investigated the functional differences between FGF2 and GDNF in the germline niche by providing these factors using a drug delivery system in vivo. Although both factors expanded the GFRA1+ subset of undifferentiated spermatogonia, the FGF2-expanded subset expressed RARG, which is indispensable for proper differentiation, 1.9-fold more frequently than the GDNF-expanded subset, demonstrating that FGF2 expands a differentiation-prone subset in the testis. Moreover, FGF2 acted on the germline niche to suppress RA metabolism and GDNF production, suggesting that FGF2 modifies germline niche functions to be more appropriate for spermatogonial differentiation. These results suggest that FGF2 contributes to induction of differentiation rather than maintenance of undifferentiated spermatogonia, indicating reconsideration of the role of FGF2 in the germline niche

Gene Targeting and Subsequent Site-Specific Transgenesis at the beta-actin (ACTB) Locus in Common Marmoset Embryonic Stem Cells

Nonhuman primate embryonic stem (ES) cells have vast promise for preclinical studies. Genetic modification in nonhuman primate ES cells is an essential technique for maximizing the potential of these cells. The common marmoset (Callithrix jacchus), a nonhuman primate, is expected to be a useful transgenic model for preclinical studies. However, genetic modification in common marmoset ES (cmES) cells has not yet been adequately developed. To establish efficient and stable genetic modifications in cmES cells, we inserted the enhanced green fluorescent protein (EGFP) gene with heterotypic lox sites into the beta-actin (ACTB) locus of the cmES cells using gene targeting. The resulting knock-in ES cells expressed EGFP ubiquitously under the control of the endogenous ACTB promoter. Using inserted heterotypic lox sites, we demonstrated Cre recombinase-mediated cassette exchange (RMCE) and successfully established a monomeric red fluorescent protein (mRFP) knock-in cmES cell line. Further, a herpes simplex virus-thymidine kinase (HSV-tk) knock-in cmES cell line was established using RMCE. The growth of tumor cells originating from the cell line was significantly suppressed by the administration of ganciclovir. Therefore, the HSV-tk/ganciclovir system is promising as a safeguard for stem cell therapy. The stable and ubiquitous expression of EGFP before RMCE enables cell fate to be tracked when the cells are transplanted into an animal. Moreover, the creation of a transgene acceptor locus for site-specific transgenesis will be a powerful tool, similar to the ROSA26 locus in mice

Direct neuronal reprogramming of common marmoset fibroblasts by ASCL1, microRNA-9/9*, and microRNA-124 overexpression

The common marmoset

Research Letter Reflection Band Control of Inverse Opal Film with Photoresponse Properties of Push-Pull Type Azobenzene LC Polymers

Recommended by Luigi Nicolais DcAz2Mc and DR1Mc molecules having push-pull type of azobenzene groups are synthesized, and their photo-orientational behaviors are investigated in the polymer system. In order to understand the relationship between a molecular structure and its physical properties, electronic structure calculation is computationally carried out. Regarding to their photo response properties, the copolymers of poly(DcAz2Mc-co-M6PBMe) and poly(DR1Mc-co-M6PBMe) are infiltrated into inverse opal films, and Bragg reflection shifts are observed under photostimuli. When the linearly polarized light is irradiated, Bragg reflection bands are shifted to the longer wavelength region as reflective index increases

Naive-like ESRRB+ iPSCs with the Capacity for Rapid Neural Differentiation

Summary: Several groups have reported the existence of a form of pluripotency that resembles that of mouse embryonic stem cells (mESCs), i.e., a naive state, in human pluripotent stem cells; however, the characteristics vary between reports. The nuclear receptor ESRRB is expressed in mESCs and plays a significant role in their self-renewal, but its expression has not been observed in most naive-like human induced pluripotent stem cells (hiPSCs). In this study, we modified several methods for converting hiPSCs into a naive state through the transgenic expression of several reprogramming factors. The resulting cells express the components of the core transcriptional network of mESCs, including ESRRB, at high levels, which suggests the existence of naive-state hiPSCs that are similar to mESCs. We also demonstrate that these cells differentiate more readily into neural cells than do conventional hiPSCs. These features may be beneficial for their use in disease modeling and regenerative medicine. : Kisa et al. modified several methods for converting human induced pluripotent stem cells (hiPSCs) into a naive state, a form of pluripotency that exists in mouse embryonic stem cells (ESCs). Converted cells express components of the core transcriptional network upregulated in mouse ESCs, including ESRRB. They also show that these cells differentiate more readily into neural cells than do conventional hiPSCs. Keywords: naive pluripotency, human iPSC, reprogramming, neural differentiatio