Identification and characterization of expression profiles of neuropeptides and their GPCRs in the swimming crab, Portunus trituberculatus

Neuropeptides and their G protein-coupled receptors (GPCRs) regulate multiple physiological processes. Currently, little is known about the identity of native neuropeptides and their receptors in Portunus trituberculatus. This study employed RNA-sequencing and reverse transcription-polymerase chain reaction (RT-PCR) techniques to identify neuropeptides and their receptors that might be involved in regulation of reproductive processes of P. trituberculatus. In the central nervous system transcriptome data, 47 neuropeptide transcripts were identified. In further analyses, the tissue expression profile of 32 putative neuropeptide-encoding transcripts was estimated. Results showed that the 32 transcripts were expressed in the central nervous system and 23 of them were expressed in the ovary. A total of 47 GPCR-encoding transcripts belonging to two classes were identified, including 39 encoding GPCR-A family and eight encoding GPCR-B family. In addition, we assessed the tissue expression profile of 33 GPCRs (27 GPCR-As and six GPCR-Bs) transcripts. These GPCRs were found to be widely expressed in different tissues. Similar to the expression profiles of neuropeptides, 20 of these putative GPCR-encoding transcripts were also detected in the ovary. This is the first study to establish the identify of neuropeptides and their GPCRs in P. trituberculatus, and provide information for further investigations into the effect of neuropeptides on the physiology and behavior of decapod crustaceans.

Initial Characterization and Expression Pattern Analysis of Tobacco (Nicotiana Tabacum) 2-Hydroxyisoflavanone Dehydratasedase Gene

The complete mRNA sequence of one tobacco (nicotiana tabacum) gene—2-hydroxyisoflavanone dehydratasedase, was amplified using the rapid amplification of cDNA ends methods based on one tobacco EST. The full-length tobacco 2-hydroxyisoflavanone dehydratasedase gene mRNA was 1,278bp containing a 966 bp open reading frame, which encodes a protein of 321 amino acids. Sequence analysis revealed that the 2-hydroxyisoflavanone dehydratasedase of tobacco shares high homology with the 2-hydroxyisoflavanone dehydratasedase of nicotiana tomentosiformis(99%), capsicum annuum(78%), potato(75%), lycopersicon pennellii(73%) and lycopersicon esculentum(72%). BLAST analysis within the tobacco high throughout genomic sequences database revealed that this gene has no intron and is a single exon gene. Results also showed that tobacco 2-hydroxyisoflavanone dehydratasedase gene has a closer genetic relationship with the 2-hydroxyisoflavanone dehydratasedase gene of nicotiana tomentosiformis. Tissue expression profile analysis revealed that the tobacco 2-hydroxyisoflavanone dehydratasedase gene was highly expressed in leaf and flower, but moderately expressed in root and stem. Our experiment established the foundation for further research on this tobacco gene.

Initial Characterization and Expression Pattern Analysis of Tobacco (Nicotiana Tabacum) HMGS Gene

3-hydroxy-3-methylglutaryl coenzyme A synthase (HMGS) is a member of condensing enzymes that catalyze a Claisen-like condensation reaction.The tobacco (nicotiana tabacum) HMGS gene was firstly characterized using the rapid amplification of cDNA ends methods based on one tobacco EST. The full-length tobacco HMGS gene mRNA was 1,773bp containing a 1389 bp open reading frame, which encodes a protein of 462 amino acids. Sequence analysis revealed that the HMGS of tobacco shares high homology with the HMGS of nicotiana tomentosiformis (96%), nicotiana attenuata (95%), Nicotiana sylvestris (95%), nicotiana benthamiana(94%), solanum lycopersicum(94%), solanum tuberosum(93%) and withania somnifera(93%). Results also showed that tobacco HMGS gene has a closer genetic relationship with the HMGS gene of withania somnifera. Tissue expression profile analysis revealed that the tobacco HMGS gene was highly expressed in flower, but moderately expressed in leaf and stem, and weakly expressed in root. Our experiment established the foundation for further research on this tobacco gene.

Initial Characterization and Expression Pattern Analysis of Tobacco (Nicotiana Tabacum) GMP Synthase Gene

The complete mRNA sequence of one tobacco (nicotiana tabacum) gene—guanosine monophosphate (GMP)synthase, was amplified using the rapid amplification of cDNA ends methods. The full-length tobacco GMP synthase gene mRNA was 2,127bp containing a 1,617 bp open reading frame, which encodes a protein of 538 amino acids. Sequence analysis revealed that the GMP synthase of tobacco shares high homology with the GMP synthase of wood tobacco(99%), nicotiana attenuata(99%), nicotiana tomentosiformis(99%), potato(92%), Lycopersicon pennellii(92%), lycopersicon esculentum(92%), capsicum annuum(91%), capsicum chinense(91%) and capsicum baccatum(90%). BLAST analysis within the tobacco high throughout genomic sequences database revealed that this gene has 5 introns and 6 exons. Results also showed that tobacco GMP synthase gene has a closer genetic relationship with the GMP synthase gene of wood tobacco. Tissue expression profile analysis revealed that the tobacco GMP synthase gene was highly expressed in leaf, but moderately expressed in root, flower and stem. Our experiment established the foundation for further research on this tobacco gene.