2026-06-22 中国科学院（CAS）
＜関連情報＞
- https://english.cas.cn/newsroom/cas-in-media/202606/t20260622_1174404.shtml
- https://www.nature.com/articles/s41422-026-01266-0
特定の遺伝子改変を施した半クローンゼブラフィッシュのワンステップ生成 One-step generation of semi-cloned zebrafish carrying a defined genetic modification
Yirui Ai,Shifeng Li,Siqi Liu,Jia Xu,Yunbin Zhang,Siyu Zhou,Zhou Zhou,Jinsong Li &Yiping Li
Cell Research Published:12 June 2026
DOI:https://doi.org/10.1038/s41422-026-01266-0
Dear Editor,
Haploid embryonic stem cells (haESCs) from multiple species, including medaka fish,1 mouse,2,3 rat,4 cattle, sheep,5 and human,6 can “fertilize” oocytes to produce semi-cloned embryos/animals and thus have potential applications in generating animal models with complex modifications. In mice, androgenetic haESCs (AG-haESCs) carrying both H19-DMR and IG-DMR deletions can efficiently support the generation of semi-cloned pups upon intracytoplasmic AG-haESC injection (ICAHCI) into oocytes, at rates of up to 30.0% of transferred embryos. Therefore, mouse DKO-AG-haESCs have been used as a genetically tractable fertilization tool for complex genetic analyses at the organismal level.7 This approach, however, has remained unavailable in zebrafish, a key model organism for studying vertebrate development and diseases.
To generate AG or parthenogenetic (PG) haploid embryos, eggs or sperm were inactivated by ultraviolet (UV) irradiation and then subjected to in vitro fertilization with untreated sperm or eggs, respectively (Supplementary information, Fig. S1a). AG and PG haploid embryos successfully developed to the blastula stage in egg water at 28.5 °C. We then isolated AG or PG blastula cells for ESC derivation. Our previous attempts resulted in stable haploid cell lines from PG embryos; however, these cells were not ESCs but heart-related cell lines.8 Moreover, the reconstructed embryos generated by injection of these cells into oocytes failed to develop to the larval stage (data not shown).
Given that ESCs are derived from the inner cell mass of blastocysts, we next asked whether haploid cells from blastulas could support the ontogeny of zebrafish in a manner similar to sperm. To this end, we adopted a conventional procedure used for nuclear transfer (NT) in zebrafish and medaka fish9 (Supplementary information, Video S1). Using intracytoplasmic haploid blastula cell injection (ICHBCI), we found that both AG and PG haploid blastula cells could successfully support the development of reconstructed embryos to the blastula stage. However, the majority of reconstructed embryos exhibited developmental arrest and morphological abnormalities, beginning at the blastula stage (Supplementary information, Table S1). Moreover, ~63.0% of the reconstructed embryos were parthenogenetic because they did not show donor-cell fluorescence at 1 day post reconstruction (dpr). The semi-cloned embryos expressed GFP from the donor and mCherry from the recipient at 3 dpr (Fig. 1a). In this preliminary experiment, we obtained 3 adult zebrafish from 931 embryos reconstructed using AG or PG haploid blastula cells (Fig. 1b; Supplementary information, Table S1). Ploidy analysis indicated that two zebrafish ( ~0.2% of reconstructed embryos) were diploid (Fig. 1c). These two semi-cloned zebrafish were female and could produce normal offspring that carried genetic traits from the founders (Fig. 1d; Supplementary information, Fig. S2). Together, these findings demonstrate that haploid blastula cells, when injected into oocytes, can give rise to fertile semi-cloned zebrafish.
