PDF(Pubmed)
Abstract：
The confinement of transgenic fish is essential to prevent their escape and reproduction in natural ecosystems. Reversible transgenic sterilization is a promising approach to control the reproduction of transgenic fish. Therefore, the present study was conducted to develop a reversibly sterile channel catfish (Ictalurus punctatus) via the transgenic overexpression of the goldfish (Carassius auratus) glutamic acid decarboxylase (GAD) gene driven by the common carp (Cyprinus carpio) β-actin promoter to disrupt normal gamma-aminobutyric acid (GABA) regulation. Three generations of GAD-transgenic fish were produced. All studied generations showed repressed reproductive performance; however, this was not always statistically significant. In F1, 5.4% of the transgenic fish showed a sexual maturity score ≥ 4 (maximum = 5) at five years of age, which was lower (p = 0.07) than that of the control group (16.8%). In the spawning experiments conducted on F1 transgenic fish at six and nine years of age, 45.5% and 20.0% of fish spawned naturally, representing lower values (p = 0.09 and 0.12, respectively) than the percentages in the sibling control fish of the same age (83.3% and 66.7%, respectively). Four of six pairs of the putative infertile six-year-old fish spawned successfully after luteinizing hormone-releasing hormone analog (LHRHa) therapy. Similar outcomes were noted in the three-year-old F2 fish, with a lower spawning percentage in transgenic fish (20.0%) than in the control (66.7%). In one-year-old F2-generation transgenic fish, the observed mean serum gonadotropin-releasing hormone (GnRH) levels were 9.23 ± 2.49 and 8.14 ± 2.21 ng/mL for the females and males, respectively. In the control fish, the mean levels of GnRH were 11.04 ± 4.06 and 9.03 ± 2.36 ng/mL for the females and males, respectively, which did not differ significantly from the control (p = 0.15 and 0.27 for females and males, respectively). There was no significant difference in the estradiol levels of the female transgenic and non-transgenic fish in the one- and four-year-old F2-generation fish. The four-year-old F2-generation male transgenic fish exhibited significantly (p < 0.05) lower levels of GnRH and testosterone than the control fish. In conclusion, while overexpressing GAD repressed the reproductive abilities of channel catfish, it did not completely sterilize transgenic fish. The sterilization rate might be improved through selection in future generations.
摘要：
限制转基因鱼对于防止其在自然生态系统中的逃逸和繁殖至关重要。可逆转基因灭菌是控制转基因鱼繁殖的一种有前途的方法。因此,本研究旨在通过转基因过表达金鱼（Carassiusauratus）谷氨酸脱羧酶（GAD）基因来开发可逆无菌通道cat鱼（Ictaluruspunctatus），该基因由鲤鱼（Cyprinuscarpio）β-肌动蛋白启动子驱动，以破坏正常的γ-氨基丁酸（GABA）调节。产生了三代GAD转基因鱼。所有研究的世代都表现出压抑的生殖表现；然而，这并不总是具有统计学意义.在F1中，5.4％的转基因鱼在5岁时表现出性成熟评分≥4（最大=5），低于对照组(16.8%)(p=0.07)。在对6岁和9岁的F1转基因鱼进行的产卵实验中，45.5%和20.0%的鱼是自然产卵的,代表较低的值（分别为p=0.09和0.12）比同龄同胞对照鱼的百分比（83.3％和66.7％，分别)。在黄体生成素释放激素类似物（LHRHa）治疗后，六对推定的六岁不育鱼中的四对成功产卵。在三岁的F2鱼中也发现了类似的结果，转基因鱼的产卵百分比（20.0％）低于对照（66.7％）。在一岁的F2代转基因鱼中，女性和男性的平均血清促性腺激素释放激素（GnRH）水平分别为9.23±2.49和8.14±2.21ng/mL，分别。在控制鱼，女性和男性的GnRH平均水平分别为11.04±4.06和9.03±2.36ng/mL，分别,与对照组没有显着差异（女性和男性的p=0.15和0.27，分别)。在一岁和四岁的F2代鱼类中，雌性转基因和非转基因鱼类的雌二醇水平没有显着差异。4岁的F2代雄性转基因鱼的GnRH和睾酮水平明显低于对照鱼（p<0.05）。总之,而过度表达GAD抑制了channel鱼的繁殖能力，它没有完全消毒转基因鱼。通过后代的选择，可以提高灭菌率。
