Disruption of amylase genes by RNA interference affects reproduction in the Pacific oyster Crassostrea gigas
|Author(s)||Huvet Arnaud1, Beguel Jean-Philippe2, Pereira Cavaleiro Nathalia3, Thomas Yoann4, Quillien Virgile1, Boudry Pierre1, Alunno-Bruscia Marianne1, Fabioux Caroline2|
|Affiliation(s)||1 : IFREMER, UMR CNRS UBO IRD Ifremer 6539, Lab Sci Environm Marin, F-29280 Plouzane, France.
2 : Univ Bretagne Occidentale, Inst Univ Europeen de la Mer, UMR CNRS UBO IRD Ifremer 6539, Lab Sci Environm Marin, F-29280 Plouzane, France.
3 : Lab Nacl Comp Cient, BR-25651071 Rio De Janeiro, Brazil.
4 : Univ Nantes, Mer Mol Sante EA 2160, F-44322 Nantes 3, France.
|Source||Journal Of Experimental Biology (0022-0949) (Company Of Biologists Ltd), 2015-06 , Vol. 218 , N. 11 , P. 1740-1747|
|WOS© Times Cited||27|
|Keyword(s)||alpha-Amylase, dsRNA, Gametogenesis, Marine bivalve, Dynamic energy budget|
|Abstract||Feeding strategies and digestive capacities can have important implications for variation in energetic pathways associated with ecological and economically important traits, such as growth or reproduction in bivalve species. Here, we investigated the role of amylase in the digestive processes of Crassostrea gigas, using in vivo RNA interference. This approach also allowed us to investigate the relationship between energy intake by feeding and gametogenesis in oysters. Double-stranded (ds)RNA designed to target the two α-amylase genes A and B was injected in vivo into the visceral mass of oysters at two doses. These treatments caused significant reductions in mean mRNA levels of the amylase genes: −50.7% and −59% mRNA A, and −71.9% and −70.6% mRNA B in 15 and 75 µg dsRNA-injected oysters, respectively, relative to controls. Interestingly, reproductive knock-down phenotypes were observed for both sexes at 48 days post-injection, with a significant reduction of the gonad area (−22.5% relative to controls) and germ cell under-proliferation revealed by histology. In response to the higher dose of dsRNA, we also observed reductions in amylase activity (−53%) and absorption efficiency (−5%). Based on these data, dynamic energy budget modeling showed that the limitation of energy intake by feeding that was induced by injection of amylase dsRNA was insufficient to affect gonadic development at the level observed in the present study. This finding suggests that other driving mechanisms, such as endogenous hormonal modulation, might significantly change energy allocation to reproduction, and increase the maintenance rate in oysters in response to dsRNA injection.|