Ectopic expression of DAZL gene in goat bone marrow-derived mesenchymal stem cells enhances the trans-differentiation to putative germ cells compared to the exogenous treatment of retinoic acid or bone morphogenetic protein 4 signalling molecules.

ABSTRACT

The plasticity of human and murine bone marrow mesenchymal stem cells (BMSCs) has been proven by their ability to trans-differentiate to multilineage cells, including germ cells. We have investigated ability of goat BMSCs to trans-differentiate to germ cells with extrinsic (e.g., retinoic acid [RA] and BMP4 signalling molecules) and intrinsic factor expression (e.g., DAZL gene ectopic expression). Having optimized the concentration of RA and BMP4, gBMSCs were treated with RA 1 µM) and BMP4 (25 ng/mL), individually and collectively. Both RA and BMP4 induced OCT4, MVH, DAZL, STELLA, NANOG and C-KIT expression, but RNF17, PIWIL2, STRA8, and SCP3 were only expressed after RA treatment. In terms of an endogenous factor, a germ cell specific gene, deleted in Azoospermia-like (DAZL), was overexpressed by plasmid and mRNA techniques. Compared with the RA treated group, DAZL ectopic expression upregulated the transcription and translation of MVH, and SCP3 was also increased at the mRNA level. The mRNA-based method had more effect on the germ cells gene expression compared to the plasmid method. Ectopic expression of the DAZL gene enhanced trans-differentiation compared to the RA-treated group. Knockdown experiments confirmed the pivotal role of DAZL in germ cell differentiation. This study provides further information on the mechanisms underlying the spermatogenesis, which will guide the derivation of post-meiotic germ cells from adult stem cells in vitro.