Chang Nai-Yun, Chan Yen-Ju, Ding Shih-Torng, Lee Yen-Hua, HuangFu Wei-Chun, Liu I-Hsuan
Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan.
Institute of Biotechnology, National Taiwan University, Taipei, Taiwan.
PLoS One. 2016 Dec 9;11(12):e0167644. doi: 10.1371/journal.pone.0167644. eCollection 2016.
To elucidate whether Sterol O-acyltransferase (Soat) mediates the absorption and transportation of yolk lipids to the developing embryo, zebrafish soat1 and soat2 were cloned and studied. In the adult zebrafish, soat1 was detected ubiquitously while soat2 mRNA was detected specifically in the liver, intestine, brain and testis. Whole mount in situ hybridization demonstrated that both soat1 and soat2 expressed in the yolk syncytial layer, hatching gland and developing cardiovascular as well as digestive systems, suggesting that Soats may play important roles in the lipid trafficking and utilization during embryonic development. The enzymatic activity of zebrafish Soat2 was confirmed by Oil Red O staining in the HEK293 cells overexpressing this gene, and could be quenched by Soat2 inhibitor Pyripyropene A (PPPA). The zebrafish embryos injected with PPPA or morpholino oligo against soat2 in the yolk showed significantly larger yolk when compared with wild-type embryos, especially at 72 hpf, indicating a slower rate of yolk consumption. Our result indicated that zebrafish Soat2 is catalytically active in synthesizing cholesteryl esters and contributes to the yolk cholesterol trafficking during zebrafish embryogenesis.
为了阐明固醇O-酰基转移酶（Soat）是否介导卵黄脂质向发育中胚胎的吸收和转运，对斑马鱼soat1和soat2进行了克隆和研究。在成年斑马鱼中，soat1在全身均有检测到，而soat2 mRNA则在肝脏、肠道、大脑和睾丸中特异性检测到。整体原位杂交表明，soat1和soat2在卵黄合胞体层、孵化腺以及发育中的心血管和消化系统中均有表达，这表明Soats可能在胚胎发育过程中的脂质运输和利用中发挥重要作用。通过在过表达该基因的HEK293细胞中进行油红O染色，证实了斑马鱼Soat2的酶活性，并且该活性可被Soat2抑制剂吡蚜酮A（PPPA）淬灭。与野生型胚胎相比，在卵黄中注射了PPPA或针对soat2的吗啉代寡核苷酸的斑马鱼胚胎，其卵黄明显更大，尤其是在受精后72小时，这表明卵黄消耗速率较慢。我们的结果表明，斑马鱼Soat2在合成胆固醇酯方面具有催化活性，并在斑马鱼胚胎发育过程中有助于卵黄胆固醇的运输。
