kristell Kellner

The European plaice (Pleuronectes platessa) is a commercial species with stock management advice given through the estimation of fish length at maturity (L50) (Mahé et al., 2007). Estimating the maturity of fish species has been worked on by the International Council for the Exploration of the Sea (ICES) that wants to harmonize the definitions, terminologies and practices used to determine the different maturity phases. Project MATO (MATurité Objective des poissons par l’histologie quantitative) will, among other things, bring knowledge on the ovarian histology of the plaice in order to correlate histological maturity with macroscopic parameters like the size color and texture of the ovaries. With this knowledge, the aim of this study is to set up a protocol that will help define the different maturity phases of Pleuronectes platessa in a completely objective way while following the ICES (2018) maturity scale

<strong>Macroscopic and histological image dataset of the European plaice (</strong><em>Pleuronectes platessa</em><strong>) ovaries </strong> <strong>Authors: </strong>Carine Sauger<sup>1</sup>, Jérôme Quinquis<sup>1</sup>, Kristell Kellner<sup>2</sup>, Clothilde Heude-Berthelin<sup>2</sup>, Mélanie Lepoittevin<sup>2</sup>, Nicolas Elie<sup>2</sup>, Laurent Dubroca<sup>1</sup> <strong>Affiliations:</strong> 1 : Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER). Laboratoire Ressources Halieutiques de Port-en-Bessin, Avenue du Général de Gaulle, 14520, Port-en-Bessin-Huppain, France 2 : Biologie des Organismes et Ecosystèmes Aquatiques (FRE 2030 BOREA). Université de Caen Normandie, Esplanade de la Paix, CS 14032, Caen, France 3 : Centre de Microscopie Appliquée à la Biologie (SF 4206 ICORE, CMABIO3). Université de Caen Normandie, Esplanade de la Paix, CS 14032, Caen, France <strong>Contents: </strong>This dataset was established during a 6 month long Master's degree internship (February to July 2019), under the IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer) project MATO (MATurité Objective des poissons par l'histologie quantitative), with the collaboration of two research facilities from the University of Caen-Normandie : BOREA (Biologie des Organismes et Ecosystèmes Aquatiques) and CMABIO<sup>3</sup> (Centre de Microscopie Appliquée à la Biologie). This dataset contains the macroscopic and the histological images of the ovaries of 151 European plaices (female, <em>Pleuronectes platessa</em>) collected along the French Coast of the English Channel (ICES area 27.7.d) in 2017, 2018 and 2019.<br> <strong>Images:</strong> <strong>Full_Ovaries_Data.zip: </strong>archive in zip format of 151 pictures (.JPG; 8Mo-9Mo; sRGB; 6016x4000 pixels) of both ovaries from 151 female plaice dissected during this study. Each photo was taken by the same person with a Nikon camera (D3200), in the same room with identical lightening methods (no flash). For each picture, both ovaries were set [...]

Chez Crassostrea gigas, huitre creuse du Pacifique, le cycle saisonnier de gestion des reserves sous forme de glycogene est tres strictement correle au cycle de reproduction. En effet, ce glycogene, stocke dans les cellules vesiculeuses du tissu de reserve, sert de support energetique a la gametogenese. Les travaux de Heude-Berthelin (2000) ont montre que le metabolisme du glycogene devait etre soumis a une regulation stricte. La mise au point d'un test biologique in vitro utilisant un analogue non metabolisable du D-glucose, le 3-O-Methyl-D-Glucose (3-OMeG) a permis de quantifier l'entree brute de glucose dans les cellules vesiculeuses isolees. L'effet de la concentration extracellulaire de 3-OMeG sur l'entree de 3-OMeG montre l'existence de plusieurs composantes dans l'entree de glucose dans la cellule: une composante saturable avec la concentration en substrat et une composante de diffusion passive non saturable. Afin de mieux definir la composante saturab...

The North Sea plaice, Pleuronectes platessa (Linnaeus, 1758), is a commonly studied commercial flatfish with poorly known ovarian histology. The following dataset is a collection of female plaice gonad images and their corresponding histological slides, collected during a complete season of the plaice’s reproduction cycle. Stereology was used to determine the percentage of different structures found throughout the ovaries. Inter-agent calibrations were accomplished in order to harmonize the stereological readings, and were based on a comprehensive reading protocol and histological lexicon that were specifically written for the plaice’s ovaries. The distribution and homogeneity of the different cell types found throughout the ovaries were also evaluated. This dataset can be used to automate the stereological reading process (through statistical learning methods for example) or to objectively determine the plaice’s maturity phase, and link that information to either macroscopic measur...

A full-length cDNA encoding a 72 kDa heat shock cognate protein (Hsc72) was isolated from a Crassostrea gigas hemocyte library. This cDNA is 75% identical to a human hsc70 cDNA. C. gigas cDNA contains a 659 amino acid open reading frame encoding a 72 kDa protein which is 87% identical to a human Hsc70 protein. Northern blotting indicated that even if the hsc72 gene was constitutively expressed in oyster hemocytes, it could be stimulated by heat shock in vitro as well as in vivo. Homologies observed both at the cDNA and protein levels, as well as the expression pattern of the hsc72 mRNA, support our conclusion that the isolated cDNA clone corresponds to an oyster heat shock cognate gene.

... BENOMAR Soumya (1) ; KELLNER Kristell (2) ; OUICHOU Ali (1) ; MATHIEU Michel (2) ; MOUKRIM Abdellatif (1 ... L'examen histologique par les colorations signalétiques (Thionine paraldéhyde et l'Azan de Romeïs), montre un cortex ganglionnaire renfermant principalement ...

This protocol was established during project MATO (MATurité Objective des poissons par l'histologie quantitative) for the evaluation of sexual maturity of exploited stock species, as well as to harmonize the sampling process of gonad extraction before the mounting between slide and slip of the gonad sections. This document follows the work of different workshops that aimed to improve the compilation of data on sexual maturity. The WKMATCH (WorKshop for MATurity staging CHairs, 2012) defined a universal evaluation grid for sexual maturity staging of different species. During this workshop, two main recommendations were made, underlining the need to improve and complete the knowledge on sexual maturity, as well as to harmonize the practices used to determine these sexual phases. This sampling protocol will be restricted to the female gonad of the megrim.

Monoclonal antibodies were developed against cerebral ganglia (CG) of the mussel Mytilus edulis by the immunization of mice with unpurified homogenates of these organs. The screening protocol of hybridoma was based upon immunohistological observations of cytocentrifugated ganglia cells. A panel of 29 monoclonal antibodies (MABs) specific of CG epitopes was harvested and subsequently used for the immunocytochemical study of CG cells. Several subpopulations of ganglia cells were specifically revealed by MABs. Identification of epitopes involved in growth control was approached via the application of a bioassay allowing the assessment of protein synthesis stimulation. MAB 42 and 46 affected amino acid incorporation induced by CG extract. These results lead to the conclusion that the epitopes recognised by these antibodies are involved in growth control. An immunoenzymatic assay was performed with CG extracts for quantitative analyses of epitopes.

The reproductive cycle of the Pacific oyster (Crassostrea gigas) is compared in two different areas (Saint-Vaast la Hougue, Normandy, and Marennes-Oléron, Charentes). Major differences were observed with respect to the success of spawning: although the general course of gametogenesis appeared to be similar, gonial mitoses were delayed on the Normandy shore and the timing of the subsequent expansion of gonadal tubules was different. However, spawning time was the same in both areas. This spawning was massive in Atlantic oysters and only partial in Normandy oysters. Storage tissue development in the gonadal area was also investigated and related to the process of gametogenesis.

In order to investigate glycogen metabolism in the oyster Crassostrea gigas, the distribution of storage cells in the whole animal was studied before histological and biochemical characterization. These cells were found mainly in the labial palps, the mantle, and gonadal area and also in gills and the digestive area. Storage cells from palps, mantle, and gonad presented the same morphological features and the same seasonal glycogen variations. Storage cells were isolated from the labial palps and the mantle plus gonadal area of the oyster by enzymatic dispersion and centrifugation through discontinuous Percoll gradient. These cells have a modal density of 1.043 g/ml. An ultrastructural study confirmed that glycogen is present in the cytoplasm either as fine particles or sequestered within vesicles. Glucose incorporation into glycogen was evaluated in vitro using [U-14C]glucose: the incorporation in isolated cells increased linearly for at least 8 hours, was proportional to the cell concentration, and showed saturation kinetics with respect to the exogenous glucose concentration.

To understand the processes involved in tissue remodeling associated with the seasonal reproductive cycle of the oyster Crassostrea gigas, we used immunodetection and expression measurements of proliferating cell nuclear antigen (PCNA). The expression of the PCNA gene was measured by real-time polymerase chain reaction in the whole gonadal area compared with laser microdissected gonad and storage tissue. Results underlined the advantage of the laser microdissection approach to detect expression, mainly for early stages of spermatogenesis. In the storage tissue, PCNA expression was reduced in the gonadal tubules, but immunolabeled hemocytes and vesicular cells were detected when the storage tissue was being restored. In the gonadal tubules, the PCNA gene was more highly expressed in males than in females. As soon as spermatogenesis was initiated, PCNA expression showed a high and constant level. In females, the expression level increased gradually until the ripe stage. The immunological approach established the involvement of peritubular cells in gonadal tubule expansion during early gametogenesis. In both sexes, gonial mitosis was immunodetected throughout the reproductive cycle. In males, the occurrence of two types of spermatogonia was ascertained by differential immunolabeling, and intragonadal somatic cell proliferation was noted. As expected, immunolabeling was never observed from stage II spermatocytes to spermatozoa. In females, positively stained cells were detected from oogonia to growing oocytes with various labeled intracellular locations.