Loading...
3 results
Search Results
Now showing 1 - 3 of 3
- Changes in the gene expression profiles of the brains of male European eels (Anguilla anguilla) during sexual maturationPublication . Churcher, Allison; Pujolar, Jose M.; Milan, Massimo; Hubbard, Peter; Martins, Rute S. T.; L. Saraiva, João; Huertas, Mar; Bargelloni, Luca; Patarnello, T.; Marino, Ilaria A. M.; Zane, Lorenzo; Canario, Adelino V. M.Background: The vertebrate brain plays a critical role in the regulation of sexual maturation and reproduction by integrating environmental information with developmental and endocrine status. The European eel Anguilla anguilla is an important species in which to better understand the neuroendocrine factors that control reproduction because it is an endangered species, has a complex life cycle that includes two extreme long distance migrations with both freshwater and seawater stages and because it occupies a key position within the teleost phylogeny. At present, mature eels have never been caught in the wild and little is known about most aspects of reproduction in A. anguilla. The goal of this study was to identify genes that may be involved in sexual maturation in experimentally matured eels. For this, we used microarrays to compare the gene expression profiles of sexually mature to immature males. Results: Using a false discovery rate of 0.05, a total of 1,497 differentially expressed genes were identified. Of this set, 991 were expressed at higher levels in brains (forebrain and midbrain) of mature males while 506 were expressed at lower levels relative to brains of immature males. The set of up-regulated genes includes genes involved in neuroendocrine processes, cell-cell signaling, neurogenesis and development. Interestingly, while genes involved in immune system function were down-regulated in the brains of mature males, changes in the expression levels of several receptors and channels were observed suggesting that some rewiring is occurring in the brain at sexual maturity. Conclusions: This study shows that the brains of eels undergo major changes at the molecular level at sexual maturity that may include re-organization at the cellular level. Here, we have defined a set of genes that help to understand the molecular mechanisms controlling reproduction in eels. Some of these genes have previously described functions while many others have roles that have yet to be characterized in a reproductive context. Since most of the genes examined here have orthologs in other vertebrates, the results of this study will contribute to the body of knowledge concerning reproduction in vertebrates as well as to an improved understanding of eel biology.
- Uncovering the immunological repertoire of the carpet shell clam Ruditapes decussatus through a transcriptomic-based approachPublication . Batista, Frederico; Churcher, Allison; Manchado, Manuel; Leitão, Alexandra; Power, DeborahThe grooved carpet-shell clam Ruditapes decussatus is native to the Northern Atlantic and Mediterranean Sea and has a high commercial value. It is one of the main native bivalve species cultured in Europe. The main objective of the present study was to gain further insights into the immunological repertoire of R. decussatus through a transcriptomic approach. Pooled mantle samples of eight R. decussatus individuals were sequenced using Illumina platform. A total of 67 132 contigs with more than 800 bp were obtained. Manual annotation of these contigs revealed 146 immune-related genes. The gene families in which the highest number of immune-related genes was observed were: C1q domain-containing proteins (63), tumor necrosis factors (15) and toll-like receptors (TLRs, 10). A total of 5 359 putative single nucleotide polymorphisms (SNPs) were identified in the 146 immune-related genes. The density of SNPs ranged between 0.04 and 7.92 SNPs/100 bp. The highest and the lowest SNP density were observed in genes of the C1q domain-containing protein family. Due to the importance of TLRs in innate immunity, we focused our attention on these membrane receptors. Ten TLRs were identified based on protein domain organization. Phylogenetic analysis revealed that R. decussatus TLRs were diverse and only 3 showed orthology with TLRs of known immune functions in other bivalve species. Moreover, our analysis suggests that lineage restricted-expansions of TLRs occurred in all mollusc taxa analysed including in venerids.
- Transcriptomics provides insight into Mytilus galloprovincialis (Mollusca: Bivalvia) mantle function and its role in biomineralisationPublication . Yarra, T.; Churcher, Allison; Felix, R. C.; Clark, M. S.; Power, DeborahThe mantle is an organ common to all molluscs and is at the forefront of the biomineralisation process. The present study used the Mediterranean mussel (Mytilus galloprovincialis) as a model species to investigate the structural and functional role of the mantle in shell formation. The transcriptomes of three regions of the mantle edge (umbo to posterior edge) were sequenced using Illumina technology which yielded a total of 61,674,325 reads after adapter trimming and filtering. The raw reads assembled into 179,879 transcripts with an N50 value of 1086 bp.A total of 1363 transcripts (321, 223 and 816 in regions 1, 2 and 3, respectively) that differed in abundance in the three mantle regions were identified and putative function was assigned to 54% using BLAST sequence similarity searches (cut-off less than 1 e(-10)). Morphological differences detected by histology of the three mantle regions was linked to functional heterogeneity by selecting the top five most abundant Pfam domains in the annotated 1363 differentially abundant transcripts across the three mantle regions. Calcium binding domains dominated region two (middle segment of the mantle edge). Candidate biomineralisation genes were mined and tested by qPCR. This revealed that Flp-like, a penicillin binding protein potentially involved in shell matrix maintenance of the Pacific oyster (Crassostrea gigas), had significantly higher expression in the posterior end of the mantle edge (region one). Our findings are intriguing as they indicate that the mantle edge appears to be a heterogeneous tissue, displaying structural and functional bias. (C) 2016 Elsevier B.V. All rights reserved.