Transcriptome profiling towards understanding of the morphogenesis in the scale development of blunt snout bream (Megalobrama amblycephala)

Fibroblast growth factor 10

Fibroblast growth factor 10 (FGF10) is a major morphoregulatory factor that plays essential signaling roles during vertebrate multiorgan development and homeostasis. FGF10 is predominantly expressed in mesenchymal cells and signals though FGFR2b in adjacent epithelia to regulate branching morphogenesis, stem cell fate, tissue differentiation and proliferation, in addition to autocrine roles. Genetic loss of function analyses have revealed critical requirements for FGF10 signaling during limb, lung, digestive system, ectodermal, nervous system, craniofacial and cardiac development. Heterozygous FGF10 mutations have been identified in human genetic syndromes associated with craniofacial anomalies, including lacrimal and salivary gland aplasia. Elevated Fgf10 expression is associated with poor prognosis in a range of cancers. In addition to developmental and disease roles, FGF10 regulates homeostasis and repair of diverse adult tissues and has been identified as a target for regenerative medicine.

Differentially expressed genes in head kidney of Pelteobagrus fulvidraco following Vibrio cholerae challenge

The yellow catfish (Pelteobagrus fulvidraco) is a freshwater fish with high economic value in eastern China. Nevertheless, pathogens causing bacterial diseases in P. fulvidraco have brought about huge economic loss and high mortality in artificial aquaculture. For disease control, it is critical to further understand the immune system of yellow catfish and immune-related genes with which they respond to pathogenic infections. In this study, high-throughput sequencing methods were used to analyze the transcriptomic spectrum of the head kidney from P. fulvidraco challenged by Vibrio cholera. A total of 45,544 unique transcript fragments (unigenes) were acquired after assembly and annotation, with an average length of 1,373 bp. Additionally, 674 differentially expressed genes (DEGs) were identified after stimulation with V. cholerae, 353 and 321 genes were identified as remarkably up- or downregulated, respectively. To further study the immune-related DEGs, we performed KEGG enrichment and GO enrichment. The results showed gene regulation of response to stimulus, immune response, immune system progress, response to external stimuli and cellular response to stimuli. Analysis of KEGG enrichment is important to identify chief immune related pathways. Real-time quantitative reverse transcription-PCR (qRT-PCR) results indicated 10 immune response genes that were found to be upregulated compared to a control group after 6 h of V. cholerae challenging. In summary, the results of our study are helpful to determine the defense mechanisms and immune system responses of yellow catfish in reaction to bacterial challenges.

Comparative transcriptome analysis of skin color-associated genes in leopard coral grouper (Plectropomus leopardus)

BACKGROUND

The leopard coral grouper (Plectropomus leopardus) is an important economic species in East Asia-Pacific countries. To meet the market demand, leopard coral grouper is facing overfishing and their population is rapidly declining. With the improvement of the artificial propagation technique, the leopard coral grouper has been successfully cultured by Fisheries Research Institute in Taiwan. However, the skin color of farmed individuals is often lacking bright redness. As such, the market price of farmed individuals is lower than wild-type.

RESULTS

To understand the genetic mechanisms of skin coloration in leopard coral grouper, we compared leopard coral grouper with different skin colors through transcriptome analysis. Six cDNA libraries generated from wild-caught leopard coral grouper with different skin colors were characterized by using the Illumina platform. Reference-guided de novo transcriptome data of leopard coral grouper obtained 24,700 transcripts, and 1,089 differentially expressed genes (DEGs) were found between red and brown skin color individuals. The results showed that nine candidate DEGs (epha2, sema6d, acsl4, slc7a5, hipk1, nol6, timp2, slc25a42, and kdf1) significantly associated with skin color were detected by using comparative transcriptome analysis and quantitative real-time polymerase chain reaction (qRT-PCR).

CONCLUSIONS

The findings may provide genetic information for further skin color research, and to boost the market price of farmed leopard coral grouper by selective breeding.