Jiravanichpaisal Pikul, Puanglarp Narongsak, Petkon Sasithon, Donnuea Seri, Söderhäll Irene, Söderhäll Kenneth
Molecular Aquatic Biology and Genetic Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Rajdhevee, Bangkok, Thailand.
Fish Shellfish Immunol. 2007 Oct;23(4):815-24. doi: 10.1016/j.fsi.2007.03.003. Epub 2007 Mar 14.
Shrimp undergo several morphologically different stages during development and therefore the expression of some immune-related genes such as prophenoloxidase (proPO), peroxinectin (Prx), crustin (Crus), penaeidin (Pen), transglutaminase (TGase), haemocyanin (Hc) and astakine (Ak) were determined during larval development of the shrimp (Penaeus monodon), i.e. nauplius 4 (N4), protozoea 1 and 3 (Z1 and 3), mysis 3 (My 3), post-larvae 3 (PL3) and also in haemocytes of juveniles. Semi-quantitative RT-PCR analysis showed that all transcripts were already present in the early larval stage of N4 but at different levels. The transcript of proPO was found to be extremely low or even absent at N4, whereas Prx, Crus, Pen, TGase, Hc and Ak were significantly expressed at all larval stages. Up to now expression of proPO and Prx has only been reported from haemocytes in crustaceans and in this study Prx also appeared to be expressed in stages which appear to lack haemocytes. Thus, this may suggest that Prx is expressed in other cells than haemocytes. It is well known among invertebrates that the proPO system plays a crucial role as an immune effector molecule against microbes. However, in this study, the transcript of proPO was low during the larval stages and hardly present at all at N4. This might indicate that the development of immune-competent haemocytes during the larval stages is not completed and as a consequence they are likely to be more susceptible to infectious diseases during these stages.
虾在发育过程中会经历几个形态不同的阶段，因此，在斑节对虾幼体发育过程中，即无节幼体4期（N4）、溞状幼体1期和3期（Z1和Z3）、糠虾3期（My 3）、后期幼体3期（PL3），以及幼虾血细胞中，测定了一些免疫相关基因的表达，如前酚氧化酶（proPO）、过氧化物酶（Prx）、甲壳素（Crus）、对虾抗菌肽（Pen）、转谷氨酰胺酶（TGase）、血蓝蛋白（Hc）和虾免疫蛋白（Ak）。半定量逆转录聚合酶链反应（RT-PCR）分析表明，所有转录本在N4早期幼体阶段就已存在，但水平不同。发现proPO转录本在N4期极低甚至不存在，而Prx、Crus、Pen、TGase、Hc和Ak在所有幼体阶段均有显著表达。到目前为止，仅报道过甲壳类动物血细胞中proPO和Prx的表达，而在本研究中，Prx似乎也在似乎缺乏血细胞的阶段表达。因此，这可能表明Prx在血细胞以外的其他细胞中表达。在无脊椎动物中众所周知，proPO系统作为一种针对微生物的免疫效应分子起着关键作用。然而，在本研究中，proPO转录本在幼体阶段较低，在N4期几乎完全不存在。这可能表明幼体阶段有免疫能力的血细胞发育尚未完成，因此它们在这些阶段可能更容易感染传染病。
