Molecular analysis of the seasonal expression of genes coding for different functional markers of the digestive gland of the bivalve mollusk Pecten maximus (L.).
Digestive gland cells of Pecten maximus accumulate and release lipid storage according to a seasonal cycle. For the first time in molluscs, molecular probes were developed and applied to monitor the lipid accumulation and consumption cycle related to phytoplankton blooms and phenomena of cellular proliferation and apoptosis. The molecular probes consisted of glyceraldehyde-3-phosphate dehydrogenase (GPD), which is involved in the acetylation of fatty acids; aldolase, which favours the formation of pyruvate and dihydroxyacetone; actin, an essential element of the cytoskeleton that disappears during adipocyte cell transformation; and cycline B, an ubiquitous cell cycle protein. Alpha-amylase, provided by IFREMER-Brest (France), was used to relate these different events to the animal's food supply. A positive relation between GPD and aldolase gene expressions was inversely correlated with that of actin, confirming results in mammals. In P. maximus, mRNA transcripts of GPD and aldolase decrease rapidly before gamete emissions whereas those of actin increase rapidly. After gamete emission, the mRNA levels of aldolase, GPD and alpha-amylase increase, while those of actin decrease. Cycline B mRNA transcripts indicate that the period of digestive cell proliferation is initiated during winter, prior to the release of lipids into the digestive tract and apoptosis.
Le Pennec
Gaël
G
Institut Européen de la Mer, Université de Bretagne Occidentale, UMR CNRS 6539, Site technopôle Brest Iroise, Place Nicolas Copernic, 29280 Plouzané, France. gael@mail.uni-mainz.de
Le Pennec
Marcel
M
D000199:Actins / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015415:Biomarkers / Q000032:analysis*; D019926:Cyclin B / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004064:Digestive System / Q000378:metabolism*; D005634:Fructose-Bisphosphate Aldolase / Q000235:genetics; D015870:Gene Expression; D007700:Kinetics; D008055:Lipids / Q000096:biosynthesis; D008969:Molecular Sequence Data; D008974:Mollusca / Q000201:enzymology / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012621:Seasons; D000516:alpha-Amylases / Q000235:genetics
D000199:Actins; D015415:Biomarkers; D019926:Cyclin B; D018076:DNA, Complementary; D008055:Lipids; D012333:RNA, Messenger; D000516:alpha-Amylases; D005634:Fructose-Bisphosphate Aldolase