Sun Yi-Wen, Li Fu-Gui, Chen Jie, Jiang Xia-Yun, Zou Shu-Ming
Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China.
Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China.
Gen Comp Endocrinol. 2015 Nov 1;223:1-8. doi: 10.1016/j.ygcen.2015.09.017. Epub 2015 Oct 9.
Follistatin-like 1 (Fstl1) peptides play important roles in inhibiting myoblast proliferation and differentiation. Here, we characterized and examined the expression patterns of fstl1a and -b in grass carp (Ctenopharyngodon idellus). These genes encode 314 aa and 310 aa peptides, respectively, sharing a sequence identity of 83%. Except for the existence of the follistatin-N-terminal (FOLN) and Kazal-type 2 serine protease inhibitor (Kazal 2) domains, grass carp Fstl1a and -b do not share amino acid sequence similarity with Fst1 and -b. Both fstl1a and -b mRNAs were widely expressed in adult tissues. During embryogenesis, grass carp fstl1a and -b mRNA was detected in the presomitic mesoderm and somites at 12h post fertilization (hpf). At 24hpf, fstl1a mRNA was expressed in the hindbrain, somites, notochord and tailbud, while fstl1b mRNA was only detected in the tailbud. At 36hpf, fstl1a mRNA was detected in the hindbrain and notochord, and fstl1b was also expressed in the notochord. Furthermore, fstl1a and -b were downregulated in brain and liver tissue following injection with 10 or 50μg hGH, while fstl1b was significantly up-regulated in muscle tissue after 10μg hGH treatment. Both fstl1a and -b were significantly up-regulated at 2, 4 or 6days of nutrient restriction, and fstl1a was still highly expressed in the liver and muscle after 3days of refeeding, as was fstl1b in the brain and muscle. The expression of these genes returned to near control levels following 6days of refeeding. Our findings suggest that the two fstls play important but divergent roles in embryonic development and tissue growth regulation in grass carp.
类卵泡抑素1（Fstl1）肽在抑制成肌细胞增殖和分化中发挥重要作用。在此，我们对草鱼（Ctenopharyngodon idellus）中fstl1a和 -b的表达模式进行了表征和研究。这些基因分别编码314个氨基酸和310个氨基酸的肽，序列同一性为83%。除了存在卵泡抑素N端（FOLN）和卡扎尔型2丝氨酸蛋白酶抑制剂（Kazal 2）结构域外，草鱼Fstl1a和 -b与Fst1和 -b没有氨基酸序列相似性。fstl1a和 -b mRNA在成体组织中广泛表达。在胚胎发育过程中，受精后12小时（hpf）在体节中胚层和体节中检测到草鱼fstl1a和 -b mRNA。在24hpf时，fstl1a mRNA在后脑、体节、脊索和尾芽中表达，而fstl1b mRNA仅在尾芽中检测到。在36hpf时，fstl1a mRNA在后脑和脊索中检测到，fstl1b也在脊索中表达。此外，注射10或50μg hGH后，fstl1a和 -b在脑和肝组织中下调，而10μg hGH处理后fstl1b在肌肉组织中显著上调。在营养限制的第2、4或6天，fstl1a和 -b均显著上调，再投喂3天后，fstl1a在肝脏和肌肉中仍高表达，fstl1b在脑和肌肉中也是如此。再投喂6天后，这些基因的表达恢复到接近对照水平。我们的研究结果表明，这两种fstls在草鱼胚胎发育和组织生长调节中发挥重要但不同的作用。
