@article {8133, title = {Gonadal transcriptomes associated with sex phenotypes provide potential male and female candidate genes of sex determination or early differentiation in Crassostrea gigas, a sequential hermaphrodite mollusc.}, journal = {BMC Genomics}, volume = {22}, year = {2021}, month = {2021 Aug 09}, pages = {609}, abstract = {

BACKGROUND: In the animal kingdom, mollusca is an important phylum of the Lophotrochozoa. However, few studies have investigated the molecular cascade of sex determination/early gonadal differentiation within this phylum. The oyster Crassostrea gigas is a sequential irregular hermaphrodite mollusc of economic, physiological and phylogenetic importance. Although some studies identified genes of its sex-determining/-differentiating pathway, this particular topic remains to be further deepened, in particular with regard to the expression patterns. Indeed, these patterns need to cover the entire period of sex lability and have to be associated to future sex phenotypes, usually impossible to establish in this sequential hermaphrodite. This is why we performed a gonadal RNA-Seq analysis of diploid male and female oysters that have not changed sex for 4 years, sampled during the entire time-window of sex determination/early sex differentiation (stages 0 and 3 of the gametogenetic cycle). This individual long-term monitoring gave us the opportunity to explain the molecular expression patterns in the light of the most statistically likely future sex of each oyster.

RESULTS: The differential gene expression analysis of gonadal transcriptomes revealed that 9723 genes were differentially expressed between gametogenetic stages, and 141 between sexes (98 and 43 genes highly expressed in females and males, respectively). Eighty-four genes were both stage- and sex-specific, 57 of them being highly expressed at the time of sex determination/early sex differentiation. These 4 novel genes including Trophoblast glycoprotein-like, Protein PML-like, Protein singed-like and PREDICTED: paramyosin, while being supported by RT-qPCR, displayed sexually dimorphic gene expression patterns.

CONCLUSIONS: This gonadal transcriptome analysis, the first one associated with sex phenotypes in C. gigas, revealed 57 genes highly expressed in stage 0 or 3 of gametogenesis and which could be linked to the future sex of the individuals. While further study will be needed to suggest a role for these factors, some could certainly be original potential actors involved in sex determination/early sex differentiation, like paramyosin and could be used to predict the future sex of oysters.

}, keywords = {Animals, Crassostrea, Female, Gene Expression Profiling, Gonads, Humans, Male, Phenotype, Phylogeny, Sex Differentiation, Transcriptome}, issn = {1471-2164}, doi = {10.1186/s12864-021-07838-1}, author = {Broquard, Coralie and Saowaros, Suwansa-Ard and Lepoittevin, M{\'e}lanie and Degremont, Lionel and Lamy, Jean-Baptiste and Morga, Benjamin and Elizur, Abigail and Anne-Sophie Martinez} } @article {6940, title = {Regulation of Extracellular Matrix Synthesis by Shell Extracts from the Marine Bivalve Pecten maximus in Human Articular Chondrocytes- Application for Cartilage Engineering.}, journal = {Mar Biotechnol (NY)}, volume = {20}, year = {2018}, month = {2018 Aug}, pages = {436-450}, abstract = {

The shells of the bivalve mollusks are organo-mineral structures predominantly composed of calcium carbonate, but also of a minor organic matrix, a mixture of proteins, glycoproteins, and polysaccharides. These proteins are involved in mineral deposition and, more generally, in the spatial organization of the shell crystallites in well-defined microstructures. In this work, we extracted different organic shell extracts (acid-soluble matrix, acid-insoluble matrix, water-soluble matrix, guanidine HCl/EDTA-extracted matrix, referred as ASM, AIM, WSM, and EDTAM, respectively) from the shell of the scallop Pecten maximus and studied their biological activities on human articular chondrocytes (HACs). We found that these extracts differentially modulate the biological activities of HACs, depending on the type of extraction and the concentration used. Furthermore, we showed that, unlike ASM and AIM, WSM promotes maintenance of the chondrocyte phenotype in monolayer culture. WSM increased the expression of chondrocyte-specific markers (aggrecan and type II collagen), without enhancing that of the main chondrocyte dedifferentiation marker (type I collagen). We also demonstrated that WSM could favor redifferentiation of chondrocyte in collagen sponge scaffold in hypoxia. Thus, this study suggests that the organic matrix of Pecten maximus, particularly WSM, may contain interesting molecules with chondrogenic effects. Our research emphasizes the potential use of WSM of Pecten maximus for cell therapy of cartilage.

}, keywords = {Aged, Aged, 80 and over, Aggrecans, Animal Shells, Animals, Cell Differentiation, Cells, Cultured, Chondrocytes, Collagen Type II, Extracellular Matrix, Gene Expression Profiling, Humans, Middle Aged, Pecten, Phenotype}, issn = {1436-2236}, doi = {10.1007/s10126-018-9807-7}, author = {Bouyoucef, Mouloud and Rakic, Rodolphe and G{\'o}mez-Leduc, Tangni and Latire, Thomas and Marin, Fr{\'e}d{\'e}ric and Leclercq, Sylvain and Carreiras, Franck and Antoine Serpentini and Lebel, Jean-Marc and Gal{\'e}ra, Philippe and Legendre, Florence} } @article {3631, title = {Looking for the bird Kiss: evolutionary scenario in sauropsids.}, journal = {BMC Evol Biol}, volume = {14}, year = {2014}, month = {2014}, pages = {30}, abstract = {

BACKGROUND: The neuropeptide Kiss and its receptor KissR are key-actors in the brain control of reproduction in mammals, where they are responsible for the stimulation of the activity of GnRH neurones. Investigation in other vertebrates revealed up to 3 Kiss and 4 KissR paralogs, originating from the two rounds of whole genome duplication in early vertebrates. In contrast, the absence of Kiss and KissR has been suggested in birds, as no homologs of these genes could be found in current genomic databases. This study aims at addressing the question of the existence, from an evolutionary perspective, of the Kisspeptin system in birds. It provides the first large-scale investigation of the Kisspeptin system in the sauropsid lineage, including ophidian, chelonian, crocodilian, and avian lineages.

RESULTS: Sauropsid Kiss and KissR genes were predicted from multiple genome and transcriptome databases by TBLASTN. Phylogenetic and syntenic analyses were performed to classify predicted sauropsid Kiss and KissR genes and to re-construct the evolutionary scenarios of both gene families across the sauropsid radiation.Genome search, phylogenetic and synteny analyses, demonstrated the presence of two Kiss genes (Kiss1 and Kiss2 types) and of two KissR genes (KissR1 and KissR4 types) in the sauropsid lineage. These four genes, also present in the mammalian lineage, would have been inherited from their common amniote ancestor. In contrast, synteny analyses supported that the other Kiss and KissR paralogs are missing in sauropsids as in mammals, indicating their absence in the amniote lineage. Among sauropsids, in the avian lineage, we demonstrated the existence of a Kiss2-like gene in three bird genomes. The divergence of these avian Kiss2-like sequences from those of other vertebrates, as well as their absence in the genomes of some other birds, revealed the processes of Kiss2 gene degeneration and loss in the avian lineage.

CONCLUSION: These findings contribute to trace back the evolutionary history of the Kisspeptin system in amniotes and sauropsids, and provide the first molecular evidence of the existence and fate of a Kiss gene in birds.

}, keywords = {Amino Acid Sequence, Animals, Avian Proteins, Biological Evolution, Birds, Humans, Kisspeptins, Molecular Sequence Data, Phylogeny, Receptors, G-Protein-Coupled, Reptiles, Sequence Alignment, Synteny}, issn = {1471-2148}, doi = {10.1186/1471-2148-14-30}, author = {Pasquier, J{\'e}r{\'e}my and Anne-Gaelle Lafont and Karine Rousseau and Qu{\'e}rat, Bruno and Chemineau, Philippe and Sylvie Dufour} }