%0 Journal Article %J Journal of Comparative Endocrinology %D 2019 %T Molecular evolution and functional characterisation of insulin related peptides in molluscs: Contributions of Crassostrea gigas genomic and transcriptomic-wide screening %A Maëva Cherif–Feildel %A Clothilde Berthelin %A Béatrice Adeline %A Guillaume Rivière %A Pascal Favrel %A Kristell Kellner-Cousin %X

Insulin Related Peptides (IRPs) belong to the insulin superfamily and possess a typical structure with two chains,
B and A, linked by disulphide bonds. As the sequence conservation is usually low between members, IRPs are
classified according to the number and position of their disulphide bonds. In molluscan species, the first IRPs
identified, named Molluscan Insulin-related Peptides (MIPs), exhibit four disulphide bonds. The genomic and
transcriptomic data screening in the Pacific oyster Crassostrea gigas (Mollusc, Bivalvia) allowed us to identify six
IRP sequences belonging to three structural groups. Cg-MIP1 to 4 have the typical structure of MIPs with four
disulphide bonds. Cg-ILP has three disulphide bonds like vertebrate Insulin-Like Peptides (ILPs). The last one,
Cg-MILP7 has a significant homology with Drosophila ILP7 (DILP7) associated with two additional cysteines
allowing the formation of a fourth disulphide bond. The phylogenetic analysis points out that ILPs may be the
most ancestral form. Moreover, it appears that ILP7 orthologs are probably anterior to lophotrochozoa and
ecdysozoa segregation. In order to investigate the diversity of physiological functions of the oyster IRPs, we
combine in silico expression data, qPCR measurements and in situ hybridization. The Cg-ilp transcript, mainly
detected in the digestive gland and in the gonadal area, is potentially involved in the control of digestion and
gametogenesis. The expression of Cg-mip4 is mainly associated with the larval development. The Cg-mip
transcript shared by the Cg-MIP1, 2 and 3, is mainly expressed in visceral ganglia but its expression was also
observed in the gonads of mature males. This pattern suggested the key roles of IRPs in the control of sexual
reproduction in molluscan species.

%B Journal of Comparative Endocrinology %V 271 %P 15-29 %G eng %9 research %0 Journal Article %J Journal of Molluscan Studies %D 2016 %T Differential protein expression during sperm maturation and capacitation in an hermaphroditic bivalve, Pecten maximus (Linnaeus, 1758) %A Boonmee, A %A Clothilde Heude-Berthelin %A Kingtong, S %A Pauletto, M %A Bernay, B %A Adeline, B %A Suquet, M %A Pascal Sourdaine %A Kristell Kellner-Cousin %B Journal of Molluscan Studies %P 1-10 %8 09/2016 %G eng %0 Journal Article %J Environ Sci Pollut Res Int %D 2015 %T The endocrine-disrupting effect and other physiological responses of municipal effluent on the clam Ruditapes decussatus. %A Mezghani-Chaari, Sawssan %A Machreki-Ajmi, Monia %A Tremolet, Gauthier %A Kristell Kellner-Cousin %A Geffard, Alain %A Minier, Christophe %A Hamza-Chaffai, Amel %X

In order to document the potential endocrine disrupting and toxic effect of the municipal wastewater effluents discharged into the Sfax coastal area (South of Tunisia), specimens of clam R. decussatus were collected from a reference site and were in vivo exposed to treated sewage effluent for 30 days. To this end, estrogenic and androgenic activities were measured in the gills to assess potential accumulation and regulation of active compounds. After effluent exposure androgenic activity in organic extracts increased up to fivefold compared to controls and remained elevated, while estrogenic activity was not significantly affected by exposure. As a consequence, remarkable disruptions in the gametogenesis activity, glycogen content, and Vitellogenin-like protein levels in male clams were observed. A parallel analysis of heavy metals in clam tissues was determined. A significant uptake of Ni, Zn, and Pb in soft tissues of exposed clams was observed. The significant increase of malondialdehyde (MDA) concentrations as a function of exposure time implies that clams have been exposed to an oxidative stress probably due to the presence of high metal concentrations in sewage effluent. Correlation analysis has revealed a statistically significant and positive relationship between MDA levels and metal concentrations in clams' tissues. The acetylcholinesterase activity was not significantly affected by exposure. Altogether, these results showed that a short-term exposure to a mixture of chemical compounds released by the Sfax wastewater treatment plant induce adverse physiological and reproductive effects in R. decussatus. Further studies are underway in order to evaluate its long-term impacts on aquatic wildlife in the gulf of Gabes area.

%B Environ Sci Pollut Res Int %V 22 %P 19716-28 %8 2015 Dec %G eng %N 24 %R 10.1007/s11356-015-5199-7 %0 Journal Article %J Environ Sci Pollut Res Int. %D 2015 %T The endocrine-disrupting effect and other physiological responses of municipal effluent on the clam Ruditapes decussatus %A Mezghani-Chaari, Sawssan %A Monia Machreki-Ajmi %A Gauthier Tremolet %A Kristell Kellner-Cousin %A Alain Geffard %A Christophe Minier %A Hamza-Chaffai, Amel %B Environ Sci Pollut Res Int. %V 22 %P 19716-28 %G eng %N 24 %9 research