【作者】 么宗利； 王萍； 来琦芳；

【Author】 YAO Zong-li;WANG ping;LAI Qi-fang;Research Center for Saline Fisheries Technology, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences;

【机构】 中国水产科学研究院东海水产研究所中国水产科学研究院盐碱地渔业工程技术中心；

【摘要】 以青海湖裸鲤(Gymnocypris przewalskii)为研究对象,采用半定量和定量PCR法研究HCO3–分泌相关基因SLC4(solute carrier family 4)和SLC26(solute carrier family 26)家族slc4a1、slc4a2、slc4a4和slc26a6基因组织分布情况,并对不同盐碱环境下肠道中SLC基因家族的表达情况进行定量分析,以期揭示青海湖裸鲤适应盐碱环境的肠道调节机制。结果表明,slc4a1、slc4a2、slc4a4和slc26a6基因在鳃、肝脏、肾脏和肠道等多个组织中均有表达,且在肠道中的表达量较高,其中slc26a6在肠道中高表达,而在鳃中表达量极低,表现出组织特异性;在碱度组、盐度组和湖水组青海湖裸鲤中肠slc4a1、slc4a2、slc4a4和slc26a6基因的表达量在胁迫4天过程中均呈现出先升高后回落的现象,其中湖水组裸鲤中肠SLC4、SLC26家族基因表达量上调最为明显,尤其是slc26a6基因表达量最高上升为对照组的4.9倍,同时,湖水组裸鲤直肠排泄HCO3–浓度也最高,说明盐碱环境下青海湖裸鲤通过肠道Cl–/HCO3–交换子(slc4a1、slc4a2、slc26a6)、Na+–HCO3–联合转运子(slc4a4)分泌和排泄机体内积累的碱,这一调节途径有助于青海湖裸鲤补偿因水环境中盐碱度升高而造成的渗透及酸碱失衡。更多还原

【Abstract】 The present study investigated how the intestine participates in the osmotic and acid-base balance regulation of G.przewalskii upon transfer to saline and alkaline conditions with physiological and molecular methods. When freshwater-acclimated G.przewalskii were transferred to saline water, alkaline water or lake water, there was a significant increase of base excretion into the rectal fluids. Slc4a1, slc4a2 and slc26a6 genes were expressed in multiple tissues, and highly expressed in intestine, while slc26a6 expression in the gill was the lowest, exhibiting tissue specificity. The significant changes in relative m RNA expressions of investigated genes in the mid-intestine were detected on day 3 of alkaline water exposure except the slc4a1 gene. While transferred to saline or lake water, the relative m RNA expressions of all investigated genes in the mid-intestine were significantly elevated on day 2. The increases of SLC gene family m RNA expressions were consistent with the increase in rectal base secretion following saline-alkaline water transfer. These results revealed that, when freshwater-acclimated G.przewalskii were exposed to saline water, they up-regulated the expression of SLC4 and SLC26 gene families in the intestine to increase the synthesis of the relevant transporters, which could aid to excrete alkaline substances(HCO3–) into the rectal fluid and stimulate the intestinal water absorption.更多还原