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Abstract Background Carex L. is one of the largest genera in the Cyperaceae family and an important vascular plant in the ecosystem. However, the genetic background of Carex is complex and the classification is not clear. In order to investigate the gene function annotation of Carex, RNA-sequencing analysis was performed. Simple sequence repeats (SSRs) were generated based on the Illumina data and then were utilized to investigate the genetic characteristics of the 79 Carex germplasms. Results In this study, 36,403 unigenes with a total length of 41,724,615 bp were obtained and annotated based on GO, KOG, KEGG, NR databases. The results provide a theoretical basis for gene function exploration. Out of 8776 SSRs, 96 pairs of primers were randomly selected. One hundred eighty polymorphic bands were amplified with a polymorphism rate of 100% based on 42 pairs of primers with higher polymorphism levels. The average band number was 4.3 per primer, the average distance value was 0.548, and the polymorphic information content was ranged from 0.133 to 0.494. The number of observed alleles (Na), effective alleles (Ne), Nei’s (1973) gene diversity (H), and the Shannon information index (I) were 2.000, 1.376, 0.243, and 0.391, respectively. NJ clustering divided into three groups and the accessions from New Zealand showed a similar genetic attribute and clustered into one group. UPGMA and PCoA analysis also revealed the same result. The analysis of molecular variance (AMOVA) revealed a superior genetic diversity within accessions than between accessions based on geographic origin cluster and NJ cluster. What’s more, the fingerprints of 79 Carex species are established in this study. Different combinations of primer pairs can be used to identify multiple Carex at one time, which overcomes the difficulties of traditional identification methods. Conclusions The transcriptomic analysis shed new light on the function categories from the annotated genes and will facilitate future gene functional studies. The genetic characteristics analysis indicated that gene flow was extensive among 79 Carex species. These markers can be used to investigate the evolutionary history of Carex and related species, as well as to serve as a guide in future breeding projects.

Background: Carex L. is one of the largest genera in the Cyperaceae family and an important vascular plant in the ecosystem. However, the genetic background of Carex is complex and the classification is not clear. In order to investigate the gene function annotation of Carex, RNA-sequencing analysis was performed. Simple sequence repeats (SSRs) were generated based on the Illumina data and then were utilized to investigate the genetic characteristics of the 79 Carex germplasms. Results: In this study, 36,403 unigenes with a total length of 41,724,615 bp were obtained and annotated based on GO, KOG, KEGG, NR databases. The results provide a theoretical basis for gene function exploration. Out of 8776 SSRs, 96 pairs of primers were randomly selected. One hundred eighty polymorphic bands were amplified with a polymorphism rate of 100% based on 42 pairs of primers with higher polymorphism levels. The average band number was 4.3 per primer, the average distance value was 0.548, and the polymorphic information content was ranged from 0.133 to 0.494. The number of observed alleles (Na), effective alleles (Ne), Nei's (1973) gene diversity (H), and the Shannon information index (I) were 2.000, 1.376, 0.243, and 0.391, respectively. NJ clustering divided into three groups and the accessions from New Zealand showed a similar genetic attribute and clustered into one group. UPGMA and PCoA analysis also revealed the same result. The analysis of molecular variance (AMOVA) revealed a superior genetic diversity within accessions than between accessions based on geographic origin cluster and NJ cluster. What's more, the fingerprints of 79 Carex species are established in this study. Different combinations of primer pairs can be used to identify multiple Carex at one time, which overcomes the difficulties of traditional identification methods. Conclusions: The transcriptomic analysis shed new light on the function categories from the annotated genes and will facilitate future gene functional studies. The genetic characteristics analysis indicated that gene flow was extensive among 79 Carex species. These markers can be used to investigate the evolutionary history of Carex and related species, as well as to serve as a guide in future breeding projects. [ABSTRACT FROM AUTHOR]

Background: Aquaculture production is expected to double by 2030, and demands for aquafeeds and raw materials are expected to increase accordingly. Sustainable growth of aquaculture will require the development of highly nutritive and functional raw materials to efficiently replace fish meal. Enzymatic hydrolysis of marine and aquaculture raw materials could bring new functionalities to finished products. The aim of this study was to determine the zootechnical and transcriptomic performances of protein hydrolysates of different origins (tilapia, shrimp, and a combination of the two) in European seabass (Dicentrarchux labrax) fed a low fish meal diet (5%), for 65 days. Results: Results were compared to a positive control fed with 20% of fish meal. Growth performances, anterior intestine histological organization and transcriptomic responses were monitored and analyzed. Dietary inclusion of protein hydrolysates in the low fish meal diet restored similar growth performances to those of the positive control. Inclusion of dietary shrimp hydrolysate resulted in larger villi and more goblet cells, even better than the positive control. Transcriptomic analysis of the anterior intestine showed that dietary hydrolysate inclusion restored a pattern of intestinal gene expression very close to the pattern of the positive control. However, as compared to the low fish meal diet and depending on their origin, the different hydrolysates did not modulate metabolic pathways in the same way. Dietary shrimp hydrolysate inclusion modulated more metabolic pathways related to immunity, while nutritional metabolism was more impacted by dietary tilapia hydrolysate. Interestingly, the combination of the two hydrolysates enhanced the benefits of hydrolysate inclusion in diets: more genes and metabolic pathways were regulated by the combined hydrolysates than by each hydrolysate tested independently. Conclusions: Protein hydrolysates manufactured from aquaculture by-products are promising candidates to help replace fish meal in aquaculture feeds without disrupting animal metabolism and performances. [ABSTRACT FROM AUTHOR]

The ridgetail white prawn Exopalaemon carinicauda is one of the major commercial mariculture species in eastern China. However, only limited molecular markers are currently available due to the lack of genome information, which hinders its genetic and breeding studies. In this study, we identified new simple sequence repeats from transcriptome sequences by Illumina Hiseq 2500 platform. A total of 14273 SSR loci were identified from 130,082 assembled transcripts, with 6590 pairs of PCR primers designed. A total of 12,155 sequences containing SSR were predicted; and 2764 (22.74%) transcripts had significant matches to the NCBI non redundant protein (Nr) database. 11,563 transcripts were assigned into gene ontology (GO) categories. A set of 200 primers selected randomly were synthesized, of which 152 (76.0%) were successfully amplified. Further test with 60 pairs of polymorphic SSR primers to evaluate the genetic diversity of 30 wild populations and 43 loci were polymorphic, which had a polymorphic information content between 0.204 and 0.911. The results enriched genomic resources of E. carinicauda and provided powerful information for future conservation and breeding researches. [ABSTRACT FROM AUTHOR]

The pikeperch ( Sander lucioperca L.) is one of the most economically important freshwater species and has been recently explored as a potential candidate for aquaculture. To facilitate pikeperch research, we sequenced its transcriptome and developed a set of microsatellite markers. We conducted Illumina RNA-sequencing and obtained over 50 million reads from a pooled cDNA library of different tissues. The clean reads were de novo assembled into 56,746 transcripts, with an average length of 1474 bp. The annotation analysis demonstrated 37,386 transcripts (65.9%) with homologous sequences in the NCBI Nr protein database. Of these annotated transcripts, 18,576 sequences were successfully assigned into Gene Ontology (GO) terms, 23,566 transcripts into the Cluster of Orthologous Groups (COG), and 12,081 transcripts to 322 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Totally, 16,368 SSRs (≥10 bp) were detected from 11,921 unigenes. The validation of randomly selected 300 SSR markers demonstrated 87.0% of the markers can be successfully amplified, suggesting RNA-Seq is an efficient tool for the development of molecular markers. This study provides not only a valuable transcriptomic resource, but also a set of SSR markers for basic as well as applied research in pikeperch. [ABSTRACT FROM AUTHOR]

The ridgetail white prawn Exopalaemon carinicauda is one of the major commercial mariculture species in eastern China. However, only limited molecular markers are currently available due to the lack of genome information, which hinders its genetic and breeding studies. In this study, we identified new simple sequence repeats from transcriptome sequences by Illumina Hiseq 2500 platform. A total of 14273 SSR loci were identified from 130,082 assembled transcripts, with 6590 pairs of PCR primers designed. A total of 12,155 sequences containing SSR were predicted; and 2764 (22.74%) transcripts had significant matches to the NCBI non redundant protein (Nr) database. 11,563 transcripts were assigned into gene ontology (GO) categories. A set of 200 primers selected randomly were synthesized, of which 152 (76.0%) were successfully amplified. Further test with 60 pairs of polymorphic SSR primers to evaluate the genetic diversity of 30 wild populations and 43 loci were polymorphic, which had a polymorphic information content between 0.204 and 0.911. The results enriched genomic resources of E. carinicauda and provided powerful information for future conservation and breeding researches.