Germline replacement by blastula cell transplantation in the fish medaka.

Mingyou Li,Jianxing Song,Hongyan Xu,Yunhan Hong,Ni Hong

doi:10.1038/srep29658

Mingyou Li, Jianxing Song + Show 3 more

Open Access

https://doi.org/10.1038/srep29658

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Abstract

Primordial germ cell (PGC) specification early in development establishes the germline for reproduction and reproductive technologies. Germline replacement (GR) is a powerful tool for conservation of valuable or endangered animals. GR is achievable by germ cell transplantation into the PGC migration pathway or gonads. Blastula cell transplantation (BCT) can also lead to the chimeric germline containing PGCs of both donor and host origins. It has remained largely unknown whether BCT is able to achieve GR at a high efficiency. Here we report efficient GR by BCT into blastula embryos in the fish medaka (Oryzias latipes). Specifically, dnd depletion completely ablated host PGCs and fertility, and dnd overexpression remarkably boosted PGCs in donor blastulae. BCT between normal donor and host produced a germline transmission rate of ~4%. This rate was enhanced up to ~30% upon PGC boosting in donors. Most importantly, BCT between PGC-boosted donors and PGC-ablated hosts led to more than 90% fertility restoration and 100% GR. Therefore, BCT features an extremely high efficiency of fertility recovery and GR in medaka. This finding makes medaka an ideal model to analyze genetic and physiological donor-host compatibilities for BCT-mediated surrogate production and propagation of endangered lower vertebrates and biodiversity.

Highlights

Used for the production of germline chimeras via blastocyst transplantation
We show that dnd depletion is 100% efficient for host sterilization via abolishing primordial germ cell (PGC) formation, and that dnd overexpression remarkably enhances the efficiency of germline chimera formation via increasing the PGC number in donor blastula cells
BGR is 100% phenotypically pigmented and genetically heterozygous (50%) for wild-type melanophores, and 66.6% positive for GFP-labeled PGCs or RFP-labeled liver but 33.3% for Vg or Lr transgenes according to the breeding scheme (Fig. 1)

Summary

Introduction

Used for the production of germline chimeras via blastocyst transplantation. In zebrafish, BCT produces germline chimeras at a low efficiency by using normal blastula embryos[16,17] but at a high efficiency in dnd depleted blastula embryos[18]. Medaka PGCs from early embryonic cells can be specified in culture[22] and are able to colonize the host germline upon blastula transplantation[15]. We show that dnd depletion is 100% efficient for host sterilization via abolishing PGC formation, and that dnd overexpression remarkably enhances the efficiency of germline chimera formation via increasing the PGC number in donor blastula cells. BCT between PGC-boosted donor and PGC-ablated host leads to a 90% high efficiency of fertility restoration and 100% GR. This finding makes medaka an ideal model organism to analyze biological and technical donor-host compatibilities for BCT-mediated surrogate production and propagation of endangered lower vertebrates and their biodiversities

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