Lee Ji-Hyun, Momani Jalal, Kim Young Mog, Kang Chang-Keun, Choi Jung-Hwa, Baek Hae-Ja, Kim Hyun-Woo
Interdisciplinary Program of Biomedical Engineering, Pukyong National University, Busan 608-737, South Korea.
Department of Marine Biology, Pukyong National University, Busan 608-737, South Korea.
Comp Biochem Physiol B Biochem Mol Biol. 2015 Jan;179:9-16. doi: 10.1016/j.cbpb.2014.09.005. Epub 2014 Sep 20.
Myostatin (MSTN), also known as GDF8, is a member of the transforming growth factor-β (TGF-β) superfamily and plays an important role in muscle growth, development, and differentiation. Recently, Lv-MSTN/GDF11, the primitive isoform of MSTN and GDF11, was identified from the shrimp Litopenaeus vannamei. The major production site for Lv-MSTN/GDF11 is in the heart, not the tail muscle, which differs from MSTNs in mammals. Among the three injected RNAs, long dsRNA was the most effective for Lv-MSTN/GDF11 knockdown and transcripts of Lv-MSTN/GDF11 decreased in both the heart (88.85%) and skeletal muscles (43.36%) 72h after injection of 10pmol of long dsRNA. We also found that higher doses of dsRNA did not lead to greater decreases in Lv-MSTN/GDF11 transcripts for amounts between 1pmol and 100pmol. Injection of Lv-MSTN/GDF11 dsRNA did not affect the upregulation of the skeletal actin gene (Lv-ACTINSK) in the tail muscle, but the expression of cytoplasmic and cardiac actins were upregulated in both the heart and tail muscle. Over the course of 8weeks of dsRNA injection, considerably higher mortality (~71%) was seen in the dsRNA-injected group compared to the control group (40%). Surviving shrimp in the dsRNA injected group had a lower growth rate due to the adverse effects of Lv-MSTN/GDF11 knockdown. Lv-MSTN/GDF11 appears to be involved in muscular or neuronal development, but not in doubling muscle fibers, as is the case with mammalian MSTN.
肌肉生长抑制素（MSTN），也被称为生长分化因子8（GDF8），是转化生长因子-β（TGF-β）超家族的成员，在肌肉生长、发育和分化中发挥着重要作用。最近，从凡纳滨对虾中鉴定出了MSTN和GDF11的原始异构体Lv-MSTN/GDF11。Lv-MSTN/GDF11的主要产生部位是心脏，而非尾肌，这与哺乳动物的MSTN不同。在三种注射的RNA中，长双链RNA对Lv-MSTN/GDF11的敲低效果最为显著，在注射10pmol长双链RNA 72小时后，心脏（88.85%）和骨骼肌（43.36%）中Lv-MSTN/GDF11的转录本均有所下降。我们还发现，对于1pmol至100pmol之间的剂量，更高剂量的双链RNA并不会导致Lv-MSTN/GDF11转录本有更大程度的下降。注射Lv-MSTN/GDF11双链RNA并不影响尾肌中骨骼肌肌动蛋白基因（Lv-ACTINSK）的上调，但心脏和尾肌中细胞质和心脏肌动蛋白的表达均上调。在双链RNA注射的8周过程中，与对照组（40%）相比，双链RNA注射组的死亡率显著更高（约71%）。由于Lv-MSTN/GDF11敲低的不利影响，双链RNA注射组中存活的对虾生长速度较低。Lv-MSTN/GDF11似乎参与了肌肉或神经元的发育，但并不像哺乳动物的MSTN那样参与肌纤维的加倍。
