|Function of the anal sacs and mid-gut in mitochondrial sulphide metabolism in the echiuran worm Urechis unicinctus|
|Ma, Y.-B.; Zhang, Z.-F.; Shao, M.-Y.; Kang, K.-H.; Zhang, L.-T.; Shi, X.-L.; Dong, Y.-P. (2012). Function of the anal sacs and mid-gut in mitochondrial sulphide metabolism in the echiuran worm Urechis unicinctus. Mar. Biol. Res. 8(10): 1026-1031. hdl.handle.net/10.1080/17451000.2012.707320|
|In: Marine Biology Research. Taylor & Francis: Oslo. ISSN 1745-1000, more|
Adaptations; Midgut; Oxidoreductases; Quinones; Sulphides; Urechis unicinctus (von Drasche, 1881) [WoRMS]; Marine
Sulphide adaptation; Sulphide:quinone oxidoreductase (SQR)
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Sulphides are naturally occurring and widely distributed, poisonous substances and sulphide:quinone oxidoreductase (SQR) has been identified to be responsible for the initial oxidation of sulphide in mitochondria. In a previous study, we found that in the sulphide-adapted species Urechis unicinctus, SQR mRNA concentrations in the mid-gut and in the anal sacs were higher than in the body wall and in the hindgut. To investigate the function of the mid-gut and anal sacs and mitochondrial sulphide metabolism in U. unicinctus, we determined the SQR protein expression in different tissues and the SQR protein expression and enzyme activity after sulphide exposure (25, 50 and 150 µM) in the anal sacs and in the mid-gut. The results showed the highest SQR expression was in the anal sacs, followed by the body wall and the hindgut, and finally the mid-gut. During exposure to 50 µM sulphide, the SQR expression in the anal sacs was significantly increased up to 2 h, reaching a maximum at 24 h and then decreasing up to 48 h. In the anal sacs, SQR enzyme activity was increased significantly up to 6 h and continued to 48 h during exposure to 50 µM sulphide, whereas in mid-gut, the SQR expression and enzyme activity did not increase significantly. We conclude that the anal sacs act as an important organ while the mid-gut only acts as an ‘assistant’ organ for mitochondrial sulphide metabolism in U. unicinctus.