Effect of stress on the ecophysiol ogical response of the sand dollar Dendraster excentricus from northwestern Mexico
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| Format: | Artículo científico |
| Langue: | en |
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Universidad Autónoma de Baja California
2014
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| _version_ | 1876426729900212224 |
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| author | Tatiana Olivares-Bañuelos |
| author_facet | Tatiana Olivares-Bañuelos |
| contents | Effect of stress on the ecophysiol ogical response of the sand dollar Dendraster excentricus from northwestern Mexico Tatiana Olivares-Bañuelos Salvador Figueroa-Flores Eugenio Carpizo-Ituarte Ciencias de la Tierra RNA DNA stress hsp 70 gene reduced oxygen In the Mexican Pacific, Dendraster excentricus , a common estuarine echinoderm, is subjec t to daily environm ental variations in tidal fluxes. Little is known about its ecophysiological respons e when individuals are exposed to temperature and oxygen change s. This study evaluates their thermal stress res ponse under normal and reduced oxygen c onditions using the RNA/DNA ratio and hsp 70 gene expression. We exposed sand dollars to different temperature and oxygen conditions. Three experimental temperatures were similar to the ones that organisms experience during one annual cycle and two were considered extr eme. Reduced oxygen condi tions were considered when levels dropp ed below 4 mg L –1 . To estimate variations in the stress-induced RNA/DNA ratio, we determined the value for males and females during a daily cycle. We also analyzed the hsp 70 expression. Under stress conditions , a significant decrease was observe d in the RNA/DNA ratios. The lowest values were detected after 6 h under normoxic conditions and hi gh temperatures seemed to induc e a major effect on the RNA/DNA r atios during the first hour of stress. Analysis of the hsp 70 expression showed significant differences. According to ou r results, thermal and reduced oxygen stress induces a reduction in the gene ral metabolism of the organi sms. These metabolic changes were observed by the decr ease in the RNA/DNA ratios and expression levels of hsp 70 (at high temperatures). We conclude that R NA/DNA ratios are a useful ecophysiological tool to evaluate the effect of partic ular stressors on the physiology of D. excentricus , and seem to be more sensitive to oxygen leve ls than to thermal stress, in contrast to the hsp 70 expression, which was more sens itive to extreme temperatures. 2014 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48031366004 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.2 Vol.40 |
| format | Artículo científico |
| id | redalyc_48031366004 |
| institution | Redalyc |
| language | en |
| publishDate | 2014 |
| publisher | Universidad Autónoma de Baja California |
| spellingShingle | Effect of stress on the ecophysiol ogical response of the sand dollar Dendraster excentricus from northwestern Mexico Tatiana Olivares-Bañuelos Ciencias de la Tierra RNA DNA stress hsp 70 gene reduced oxygen Effect of stress on the ecophysiol ogical response of the sand dollar Dendraster excentricus from northwestern Mexico Tatiana Olivares-Bañuelos Salvador Figueroa-Flores Eugenio Carpizo-Ituarte Ciencias de la Tierra RNA DNA stress hsp 70 gene reduced oxygen In the Mexican Pacific, Dendraster excentricus , a common estuarine echinoderm, is subjec t to daily environm ental variations in tidal fluxes. Little is known about its ecophysiological respons e when individuals are exposed to temperature and oxygen change s. This study evaluates their thermal stress res ponse under normal and reduced oxygen c onditions using the RNA/DNA ratio and hsp 70 gene expression. We exposed sand dollars to different temperature and oxygen conditions. Three experimental temperatures were similar to the ones that organisms experience during one annual cycle and two were considered extr eme. Reduced oxygen condi tions were considered when levels dropp ed below 4 mg L –1 . To estimate variations in the stress-induced RNA/DNA ratio, we determined the value for males and females during a daily cycle. We also analyzed the hsp 70 expression. Under stress conditions , a significant decrease was observe d in the RNA/DNA ratios. The lowest values were detected after 6 h under normoxic conditions and hi gh temperatures seemed to induc e a major effect on the RNA/DNA r atios during the first hour of stress. Analysis of the hsp 70 expression showed significant differences. According to ou r results, thermal and reduced oxygen stress induces a reduction in the gene ral metabolism of the organi sms. These metabolic changes were observed by the decr ease in the RNA/DNA ratios and expression levels of hsp 70 (at high temperatures). We conclude that R NA/DNA ratios are a useful ecophysiological tool to evaluate the effect of partic ular stressors on the physiology of D. excentricus , and seem to be more sensitive to oxygen leve ls than to thermal stress, in contrast to the hsp 70 expression, which was more sens itive to extreme temperatures. 2014 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48031366004 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.2 Vol.40 |
| title | Effect of stress on the ecophysiol ogical response of the sand dollar Dendraster excentricus from northwestern Mexico |
| topic | Ciencias de la Tierra RNA DNA stress hsp 70 gene reduced oxygen |
| url | https://www.redalyc.org/articulo.oa?id=48031366004 |