Yang Bingye, Pu Fei, Li Lingling, You Weiwei, Ke Caihuan, Feng Danqing
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; Xiamen Medical College, Xiamen 361008, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen University, Xiamen 361102, China.
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China; College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen University, Xiamen 361102, China.
Comp Biochem Physiol B Biochem Mol Biol. 2017 Apr;206:8-15. doi: 10.1016/j.cbpb.2017.01.006. Epub 2017 Jan 17.
The formation of the primary shell is a vital process in marine bivalves. Ocean acidification largely influences shell formation. It has been reported that enzymes involved in phenol oxidation, such as tyrosinase and phenoloxidases, participate in the formation of the periostracum. In the present study, we cloned a tyrosinase gene from Crassostrea angulata named Ca-tyrA1, and its potential function in early larval shell biogenesis was investigated. The Ca-tyrA1 gene has a full-length cDNA of 2430bp in size, with an open reading frame of 1896bp in size, which encodes a 631-amino acid protein that includes a 24-amino acid putative signal peptide. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis revealed that Ca-tyrA1 transcription mainly occurs at the trochophore stage, and the Ca-tyrA1 mRNA levels in the 3000ppm treatment group were significantly upregulated in the early D-veliger larvae. WMISH and electron scanning microscopy analyses showed that the expression of Ca-tyrA1 occurs at the gastrula stage, thereby sustaining the early D-veliger larvae, and the shape of its signal is saddle-like, similar to that observed under an electron scanning microscope. Furthermore, the RNA interference has shown that the treatment group has a higher deformity rate than that of the control, thereby indicating that Ca-tyrA1 participates in the biogenesis of the primary shell. In conclusion, and our results indicate that Ca-tyrA1 plays a vital role in the formation of the larval shell and participates in the response to larval shell damages in Crassostrea angulata that were induced by ocean acidification.
初级贝壳的形成是海洋双壳贝类中的一个重要过程。海洋酸化对贝壳形成有很大影响。据报道，参与酚氧化的酶，如酪氨酸酶和酚氧化酶，参与了贝壳外层的形成。在本研究中，我们从近江牡蛎中克隆了一个酪氨酸酶基因，命名为Ca-tyrA1，并研究了其在幼虫早期贝壳生物发生中的潜在功能。Ca-tyrA1基因的全长cDNA大小为2430bp，开放阅读框大小为1896bp，编码一个631个氨基酸的蛋白质，其中包括一个24个氨基酸的假定信号肽。定量逆转录-聚合酶链反应（qRT-PCR）分析表明，Ca-tyrA1转录主要发生在担轮幼虫阶段，在3000ppm处理组中，早期D形幼虫的Ca-tyrA1 mRNA水平显著上调。全胚胎原位杂交（WMISH）和电子扫描显微镜分析表明，Ca-tyrA1的表达发生在原肠胚阶段，从而维持早期D形幼虫，其信号形状为鞍状，类似于电子扫描显微镜下观察到的形状。此外，RNA干扰表明，处理组的畸形率高于对照组，从而表明Ca-tyrA1参与了初级贝壳的生物发生。总之，我们的结果表明，Ca-tyrA1在幼虫贝壳的形成中起着至关重要的作用，并参与了近江牡蛎幼虫贝壳因海洋酸化而受损的反应。
