Shang Mei, Su Baofeng, Perera Dayan A, Alsaqufi Ahmed, Lipke Elizabeth A, Cek Sehriban, Dunn David A, Qin Zhenkui, Peatman Eric, Dunham Rex A
School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
Key Laboratory of Freshwater Aquatic Biotechnology and Genetic Breeding, Ministry of Agriculture, Heilongjiang Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China.
Fish Physiol Biochem. 2018 Apr;44(2):717-733. doi: 10.1007/s10695-018-0467-3. Epub 2018 Jan 22.
Our aim was to transplant blue catfish germ line stem cells into blastulae of triploid channel catfish embryos to produce interspecific xenogenic catfish. The morphological structure of the gonads of blue catfish (Ictalurus furcatus) in ~ 90- to 100-day-old juveniles, two-year-old juveniles, and mature adults was studied histologically. Both oogonia (12-15 μm, diameter with distinct nucleus 7-8 μm diameter) and spermatogonia (12-15 μm, with distinct nucleus 6-7.5 μm diameter) were found in all ages of fish. The percentage of germ line stem cells was higher in younger blue catfish of both sexes. After the testicular tissue was trypsinized, a discontinuous density gradient centrifugation was performed using 70, 45, and 35% Percoll to enrich the percentage of spermatogonial stem cells (SSCs). Four distinct cell bands were generated after the centrifugation. It was estimated that 50% of the total cells in the top band were type A spermatogonia (diameter 12-15 μm) and type B spermatogonia (diameter 10-11 μm). Germ cells were confirmed with expression of vasa. Blastula-stage embryos of channel catfish (I. punctatus) were injected with freshly dissociated blue catfish testicular germ cells as donor cells for transplantation. Seventeen days after the transplantation, 33.3% of the triploid channel catfish fry were determined to be xenogenic catfish. This transplantation technique was efficient, and these xenogenic channel catfish need to be grown to maturity to verify their reproductive capacity and to verify that for the first time SSCs injected into blastulae were able to migrate to the genital ridge and colonize. These results open the possibility of artificially producing xenogenic channel catfish males that can produce blue catfish sperm and mate with normal channel catfish females naturally. The progeny would be all C × B hybrid catfish, and the efficiency of hybrid catfish production could be improved tremendously in the catfish industry.
我们的目标是将蓝鲶生殖系干细胞移植到三倍体沟鲶胚胎的囊胚中，以培育种间异种鲶鱼。对约90至100日龄幼鱼、两岁龄幼鱼和成年蓝鲶（斑点叉尾鮰）性腺的形态结构进行了组织学研究。在所有年龄段的鱼中均发现了卵原细胞（直径12 - 15μm，细胞核直径7 - 8μm，清晰可见）和精原细胞（直径12 - 15μm，细胞核直径6 - 7.5μm，清晰可见）。两性蓝鲶幼鱼的生殖系干细胞百分比更高。将睾丸组织用胰蛋白酶处理后，使用70%、45%和35%的 Percoll进行不连续密度梯度离心，以提高精原干细胞（SSCs）的百分比。离心后产生了四个不同的细胞带。估计顶部条带中50%的细胞为A型精原细胞（直径12 - 15μm）和B型精原细胞（直径10 - 11μm）。通过vasa的表达确认了生殖细胞。将新鲜解离的蓝鲶睾丸生殖细胞作为供体细胞注射到沟鲶（斑点叉尾鮰）囊胚期胚胎中进行移植。移植17天后，确定33.3%的三倍体沟鲶鱼苗为异种鲶鱼。这种移植技术是有效的，这些异种沟鲶需要生长至成熟，以验证其繁殖能力，并首次验证注入囊胚的SSCs能够迁移到生殖嵴并定植。这些结果为人工培育能够产生蓝鲶精子并与正常沟鲶雌性交配的异种沟鲶雄性开辟了可能性。后代将全是C×B杂交鲶鱼，这将极大提高鲶鱼养殖业中杂交鲶鱼的生产效率。
