Production of transgenic animal models with a fluorescence (i.e., green fluorescent protein; GFP) gene has been considered an important resource because such models allow real-time tracing of cellular differentiation and function [1]. Thus, several fluorescent models including mice, rats, and rabbits have been successfully developed and used widely in research. Fluorescent models in large animals, specifically cattle, are considered important resources similar to mice models, and several trials involving such models have been carried out. At the initial stage, virus-mediated gene delivery is performed to evaluate the feasibility of producing fluorescent cattle [2, 3]. The birth of somatic cell nuclear transfer (SCNT)-derived offspring [4] indicated that the speed and type of transgenic bovine models that include fluorescence could be increased. However, this was disproved due to the low efficiency of reprogramming [5]. Although some studies have reported success of transgenic cloned cattle [6, 7], but for some reason, no bovine fluorescent germ cells (i.e., sperm) with long-term expression (more than two generations) have been reported. Here, we have reported that viable frozen-semen and -blastocysts with an identified GFP-integration position from F1 transgenic bull were sufficiently isolated, indicating that F2-generation fluorescent transgenic cattle could be produced when needed via general reproductive technologies, such as artificial insemination or embryo transfer.

中文翻译：

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转基因 F2 牛胚胎通过两代显示稳定的种系传递和转基因表达的维持。

生产具有荧光（即绿色荧光蛋白；GFP）基因的转基因动物模型被认为是一种重要的资源，因为此类模型允许实时追踪细胞分化和功能 [1]。因此，包括小鼠、大鼠和兔在内的几种荧光模型已成功开发并广泛用于研究。大型动物（特别是牛）的荧光模型被认为是类似于小鼠模型的重要资源，并且已经进行了一些涉及此类模型的试验。在初始阶段，进行病毒介导的基因传递，以评估生产荧光牛的可行性 [2, 3]。体细胞核移植 (SCNT) 衍生后代 [4] 的诞生表明，可以增加包含荧光的转基因牛模型的速度和类型。然而，由于重编程效率低，这被反驳[5]。虽然有研究报道了转基因克隆牛的成功[6, 7]，但由于某种原因，没有长期表达（两代以上）的牛荧光生殖细胞（即精子）的报道。在这里，我们报告了可行的冷冻精液和囊胚F1转基因公牛的GFP整合位点被充分分离，表明在需要时可以通过人工授精或胚胎移植等通用生殖技术生产F2代荧光转基因牛。