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The mantle plays important role in the mechanism of oyster protection caused by environmental pollutants. This study aims to analyze the effect of water accommodated fraction of crude oil on the mantle of Slipper-Shaped Oyster (Crassostrea iredalei) at different doses and time exposure. The ventral and posterior segments of the mantle were fixed, and tissue sections were stained with hematoxylin-eosin, PAS-Periodic acid–Schiff, and TEM-transmission electron microscopy techniques. HE-hematoxylin and eosin, PAS-alcian, and TEM-transmission electron microscopy were used to characterize the different mucosubstances and to describe the ultrastructure-related response on a certain part of the mantle after exposure. The tissues of epithelium, connective tissue, mucus cells, pigmented cells, numerous hemolymph sinuses, shell formation, and blood sinus were recognized under a light microscope. The mucous cell was excreted in all the concentrations (control, 12.5, 25, 50, and 100% Water Acomodate Fraction) and also in the time exposure (24, 48, 72, and 96 hours). A large number of mucous cells was produced in the inner mantle cavity (IMC) and outer mantle cavity (OMC). Mucous cells increased in number with increasing WAF concentration as well as the length of exposure time. The highest number of mucus cells was observed at 100% Water Accommodate Fraction (WAF) concentration and 96 hours of exposure. The structure and function of the mantle, the shell formation, the edge of the mantle, mucous cell, muscle bundles, nerve fibers, and epithelium layer of the Slipper-Shaped Oyster (Crassostrea iredalei) were documented in this study.

In addition to cardiovascular diseases, metabolic syndrome and type 2 diabetes mellitus, obesity is associated with cognitive deficits. In rodents, it has been shown that long-term high-fat diet (HFD) consumption leads to the alteration of hypothalamic-pituitary-adrenal (HPA) axis resulting in increased corticosterone release. However, mechanisms underpinning cognitive impairments induced by long-term HFD intake are unclear. Herein we evaluated the effects of systemic administration of glucocorticoid synthesis inhibitor metyrapone on cognitive performance assessed by novel object recognition test and plasma corticosterone levels evaluated by enzyme-linked immunosorbent assay in HFD-induced obese mice. We found that metyrapone treatment alleviated recognition memory impairments in HFD-induced obese mice. Furthermore, glucocorticoid synthesis inhibitor also lowered plasma corticosterone levels in HFD-induced obese mice. Our findings indicate that hyperactivation of HPA axis resulting in elevated circulating glucocorticoid levels leads to memory impairments in HFD-induced obese mice. We identify glucocorticoid system as a potential therapeutic target for treating cognitive deficits associated with obesity condition.

A monoclonal antibody specific to sea bass (Lates calcarifer) vitellogenin (VTG) was developed, for use as a tool for monitoring endocrine disrupting chemicals (EDCs). VTG was induced in sea bass by intramuscular injection of 17β-estradiol (E2: 2 mg/kg) every three days. Blood was collected three days after the last injection. Plasma VTG was then purified by chromatography in hydroxyapatite and a sephacryl-S300 column. Characterizations of purified VTG were done by phospholipoglycoprotein staining on a native-PAGE with confirmation by mass spectrometry (LC-MS/MS). Antibody was raised in mice by injection of purified VTG. After monoclonal antibody production, the hybridoma clone No. 41 (MAb-sea bass VTG 41) was selected and developed for quantification of VTG by competitive enzyme-linked immunosorbent assay (ELISA). The ELISA method was sensitive with a detection limit of VTG 40 ng/mL. MAb-sea bass VTG 41 was specific to VTG from E2-treated sea bass and others EDCs (Nonylphenol, Benzo[a]pyrene and CdCl2). Moreover, cross-reactivity was also found in E2-treated coral grouper (Epinephelus corallicola). The ELISA method obtained from this work can be further applied for the assessment of EDCs in Thailand and Southeast Asia's aquatic environment.

The hooded oyster, Saccostrea cuccullata (Born, 1778), is an important aquaculture species on the coast of Thailand. Its aquaculture is mainly based on wild seed collection, the availability of which is becoming unstable due to environmental changes and pollution. To support aquaculture of this species, seed production in the hatchery is therefore required. Unfortunately, information on seed production is not available in this species. Therefore, the aim of this work was to study gametes and early stage larval development in order to improve current knowledge of fertilization and larval development in this species. Spermatozoa and oocytes were collected from mature oysters by a strip spawning method and characterized under a light microscope and a transmission electron microscope (TEM). In vitro fertilization was performed in 30 ppt filtrate seawater to observe developmental stages until the D-larvae. Results showed that oocytes, when fertilized with spermatozoa, underwent meiosis I (15 min) and meiosis II (30 min), indicated by the presence of the first and second polar bodies, respectively. The first cleavage, holoblastic unequal type, occurred 50 min after fertilization. A polar lobe was observed during the first cleavage and fused with one of the two cells to form one small and one large macromere. The larvae then continuously developed to trochophore larvae over 8 h. D-larvae were observed 24 h after fertilization. Results obtained from this work improve current knowledge of gametes and early developmental biology of the larvae in this species. This knowledge is important for developing hatchery methods for S. cuccullata.

Knowledge of sperm maturation process is limited in the Pacific oyster Crassostrea gigas and major factors of fertilization success of this free spawning animal are unknown. We investigated proteins associated to spermatozoa by analyzing two cellular fractions obtained from a 40-80% Percoll gradient fractioning of germ cell of mature male gonads. Mature spermatozoa were enriched in the lower Percoll fraction while the upper fraction contained less mature or earlier germ cells. A 2-DE proteomic approach was used to identify differentially expressed proteins in both fractions. We screened out 31 differential proteins (P0.05) which included 14 up-regulated and 17 down-regulated proteins. Using MALDI-TOF/TOF MS and bioinformatics search against a C. gigas database, 13 and 8 proteins were identified for the up-regulated and down-regulated groups, respectively. In the spermatozoa enriched fraction, proteins regarding flagellum formation and control, energy production and Proteosome subunit beta were increased. In less mature germ cell fraction, proteins regarding developmental processes and chaperon molecules were mainly increased. Our results improve current knowledge of proteins associated with spermatozoa maturation related to zootechnical practices used in mollusk hatcheries.This is the revised version of the manuscript "Proteomic identification of protein associated to mature spermatozoa in the Pacific oyster Crassostrea gigas" by Kingtong et al. to the Journal of Proteomics. The corrections have been done by the team carefully. This work highlight the enrichment method of spermatozoa of Pacific oyster from stripped complex sample using Percoll gradient. The results reflexed developmental stages of germ cells in gonadal tubules of this species. We have used proteomic approach to identify differentially expressed proteins in mature spermatozoa fraction compared to less mature spermatozoa fraction which provided candidates of protein associated to mature spermatozoa in the Pacific oyster. This work improves the current knowledge in marine bivalve hatchery.

00000 ăWOS:000386901500011; International audience; In order to investigate the mechanisms of final maturation and capacitation of spermatozoa in Pecten maximus, we used a 2D proteomic approach coupled with MALDI-TOF/TOF mass spectrometry (MS) and bioinformatics search against the Pecten database, to set up a reference map of the proteome of spawned spermatozoa, and identified 133 proteins on the basis of the EST database. These proteins are mainly involved in energy production, ion and electron transport (44%), cell movement (22%) and developmental processes (10%). Comparison between proteomes of spermatozoa collected before and after transit through the genital ducts of P. maximus led to the identification of differentially expressed proteins. Most of them are associated with energy metabolism (aconitate hydratase, malate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase), indicating important modifications of energy production during transit in gonoducts, potentially linked with acquisition of sperm motility. Three proteins involved in cell movement (Tektin-2, tubulin and microtubule-associated protein RP/EB family member 3) were down-regulated in spermatozoa stripped from the gonad. 40S ribosomal protein SA, involved in maturation of 40S ribosomal subunits, was also found to be down-regulated in spermatozoa obtained by induced spawning, suggesting reduction of the efficiency of RNA translation, a characteristic of late spermatozoon differentiation. These results confirm that maturation processes of P. maximus spermatozoa during transit through the gonoduct involve RNA translation, energy metabolism and structural proteins implicated in cell movement. Spermatozoa maturation processes clearly differ between P. maximus and gonochoric or alternately hermaphroditic bivalves, potentially in relation to reproductive strategies: the final maturation of the spermatozoon along the genital tract probably contributes to reduction of autofertilization in this simultaneously hermaphroditic species.

Tributyltin (TBT), an environmental pollutant in marine ecosystems, is toxic to organisms. Although contamination by and bioaccumulation and toxicity of this compound have been widely reported, its underlying molecular mechanisms remain unclear. In the present study, we exposed the Hooded oyster Saccostrea cucullata to TBT to investigate histopathological effects and proteome stress response. Animals were exposed to three TBT sub-lethal concentrations, 10, 50 and 150 μg/l for 48 h. TBT produced stress leading to histopathological changes in oyster tissues including mantle, gill, stomach and digestive diverticula. TBT induced mucocyte production in epithelia and hemocyte aggregation in connective tissue. Cell necrosis occurred when exposure dosages were high. Comparative proteome analyses of mantle protein of oysters exposed to 10 μg/l and control animals were analyzed by a 2-DE based proteomic approach. In total, 32 protein spots were found to differ (p

ATP-binding cassette (ABC) multidrug transporters confer resistance in human cancer cells as well as in pathogenic microorganisms by mediating the extrusion of various chemotherapeutic drugs out of the cell. In aquatic invertebrates, the presence of ABC transporters which are involved in the multi-xenobiotic resistance has been demonstrated. However, most studies have been confined to the MDR1 subfamily. In the present study, we characterized the expression and localization of the ABC multidrug transporters including MDR1, MRP1 and BCRP subfamily in the Indian-rock oyster Saccostrea forskali. To our knowledge, these data represent one of the first reports on the orthologues of MRP1 and BCRP in marine invertebrates. Furthermore, the observations of (i) the expression of the ABC multidrug proteins in detoxifying tissues; (ii) the induction of these transporters upon exposure to an environmental organic pollutant tributyltin (TBT); and (iii) the concentration-dependent inhibition of rhodamine efflux by TBT imply a possible role of these proteins in the export of TBT. Our findings along with previous studies suggest that the ABC multidrug transporters act as a detoxifying mechanism of various toxic agents including TBT in aquatic organisms.

The acorn barnacle (Cirripedia: Balanomorpha) is a sessile crustacean arthropod, distributing around the intertidal areas of tropical and temperate regions worldwide. Current practices for taxonomic identification are based on shell morphology and light microscopy, together with the use of scanning electron microscopy for arthropodal characters, which the latter technique requires complicated procedures. Through the recent technology of confocal light-sheet microscopy, here we demonstrate a clear description of Caudoeuraphia caudata (Pilsbry, 1916), a new record of its presence in eastern Thailand. This type of microscopy enables the high acquisition of fluorescent imaging of a whole barnacle’s body and arthropodal structures, including cirri and mouthpart imaging in three dimensions, with simple procedures for sample preparation and through harboring autofluorescence of their own barnacle structures. Hence, this technology could potentially be an alternative way for identifying acorn barnacles at the species-level and visualizing the diversity of these marine arthropods.