Rapid Amplification of 5′ cDNA End of S. Liaotungensis Choline Monooxygenase Using Inverse PCR RACE

Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5′-phosphated RT primer and two pairs of specific inverse PCR primers. Compared with the anchored PCR RACE, inverse PCR RACE has better specificity and higher amplification.

Amplification of UGPase cDNA 3＇ UTR from Saccharum Officinarum

UDP-glucose pyrophosphorylase is an important enzyme concerned with carbohydrate metabolism in plants. Cloning of UGPase is a premise for further study on molecular level, and it is also crucial for study of carbohydrate metabolism. UGPase cDNA sequence as a template, designed primer, then 3＇-untranslate region （3＇ UTR） of UGPase were amplified by 3＇-rapid amplification of cDNA ends （3＇-RACE）. The results suggested the 3＇ UTR were 243 bp, contained AATAA sequence and Poly（A）.

Cloning and Sequence Analysis of Beta-actin Gene Full Length cDNA from Trachidermus fasciatus

[Objective] The purpose of this experiment was to reveal the sequence and characteristics of Trachidermus fasciatus beta-actin gene.[Method] Using total RNA of muscle in T.fasciatus as template,three cDNA fragments of beta-actin gene in T.fasciatus were amplified by RT-PCR,5＇-RACE and 3＇-RACE.[Result] A full-length of 1905 bp beta-actin cDNA sequence in T.fasciatus,which includes a 1128 bp length open reading frame encoding a 375-amino acid peptide,was obtained.Sequence alignment of nucleotide and amino acid sequence revealed that T.fasciatus beta-actin shared high homology with that of Epinephelus coioides,Rachycentron canadum,Chrysophrys auratus and of relatively low homology with mammalian and bird.The phylogenetic analysis showed that T.fasciatus beta-actin had closest relationship with Epinephelus coioides.And RT-PCR analysis suggested that the beta-actin gene expressed in four tissues,i.e.,muscle,liver,intestine and brain.[Conclusion] The full length sequence of beta-actin gene with high conservation in T.fasciatus was obtained for the first time.

Molecular Cloning and Characterization of a DFR from Developing Seeds of Blue-grained Wheat in Anthocyanin Biosynthetic Pathway

Blue-grained wheat derived from the hybrid Triticum aestivum L. X Thinopyrum ponticum (Podp.) Barkworth et D. R. Dewey (Agropyron elongatum (Host) P. Beauv., 2n=70). The molecular biological mechanism of the biosynthetic pathway of blue pigments in the blue grain remains unclear yet. Dihydroflavonol 4-reductase (DFR) is one of the key enzymes controlling flavonoid synthesis in anthocyanin biosynthetic pathway, and may directly participate in the formation of blue pigment in the aleurone layer of blue-grained wheat. Here we cloned a DFR cDNA (TaDFR) from the developing seeds of blue-grained wheat, and four DFR genomic DNAs from Th. ponticum (ThpDFR.t), blue-grained wheat (TaDFR.bg), white-grained offspring of light blue-grained wheat (TaDFR.wg) and Chinese Spring (2n=42) (TaDFR.csg), respectively. TaDFR cDNA encodes a 354 amino-acids polypeptide with high identity to DFR from Hordeum vulgare L. (94%), Oryza sativa L. (83%), Zea mays L.(84%). The result of cluster analysis showed that TaDFR cDNA nucleotide sequence has 100% identity with that of TaDFR.csg. The four DFR genomic DNAs have extraordinary high homology and each has three introns. The differences of the four DFR genomic DNAs mainly exist in introns. Southern blotting analysis showed that there are at least 3-5 DFR copies in wheat, the copy numbers in different color grain wheats are not significantly different. The hybridization band patterns were the same, but different from that of Th. ponticum. DFR in blue-grained wheat belongs to a DFR superfamily. Northern blotting analysis indicated that the DFR expressed in the developing seeds of both blue- and white-grained wheat at 15 d after flowering (DAF), the mRNA levels of DFR reached the highest at 18 DAF, then declined quickly and disappeared at 33 DAF But the expression levels in blue-grained seeds were higher than that in white grain at the same seed developing stages. DFR transcripts accumulated in young leaves, and leaf sheaths of blue- and white-grained wheat and Th ponticum, but not detected in roots from different color wheats and developing seeds of Th. ponticum. Results indicated that there may exist some regulatory gene(s) which can increase the expression of DFR in the aleurone layer of blue-grained wheat, and thus resulting in the formation of blue pigments.

Cloning and Identification of Porcine HSPC117 Gene Differentially Expressed in F_(1)Crossbreds and Their Parents

To investigate the molecular basis of porcine heterosis, suppression subtractive hybridization （SSH） was performed to detect the differences in gene expression between porcine longissimus dorsi of Meishan X Large White （MS × LW） F1 hybrids and their parents Meishan pigs. An expression sequence tag （EST） differentially expressed was found, designated as ML556, which was homologous to a hypothetical protein HSPC117, from human hematopoietic stem/progenitor cells （HSPCs）, and the full-length cDNA of porcine HSPC117 was cloned using rapid amplification of cDNA ends （RACE） method. Translation of the mRNA transcript revealed an open reading frame （ORF） of 505 amino acid residues encoding a peroxisomal targeting signal （PTS） with theoretical molecular weight of 55 kDa. Alignment analysis revealed that the deduced protein sequence exhibit 98, 98, 98, 97, and 97% identity with that of cattle, human, dog, rat, and mouse, respectively. The tissue expression analysis indicated that the porcine HSPC117 gene is highly expressed in muscle, spleen, lung, kidney, uterus, ovary and testis, moderately expressed in fat, heart, and liver, and not expressed in stomach and small intestine. The possible role of porcine HSPC117 and its relationship with porcine heterosis were discussed.

Molecular Cloning and Characterization of a Novel Gene Involved in Fatty Acid Synthesis in Brassica napus L.

Based on the sequence of a novel expressed sequence tag （EST）, the full-length cDNA of 1 017 nucleotides was cloned from Brassica napus cv. Xiangyou 15 through rapid amplification of cDNA ends （RACE）. The gene was designated as Bnhol34 （HQ585980）, encoding a protein of 338 amino acids. BLAST analysis showed no high degree of sequence identity to any known gene. The calculated molecular weight of the Bnhol34 protein was 36.23 kDa, and the theoretical isoelectric point was 8.74. The Bnhol34 was also cloned from a high oleic acid mutant 854-1 through homologous cloning. There was no difference between the two Bnhol34 genes. Bnhol34 was localized in a tissue-specific manner in B. napus, and its expression level was about eight-fold greater in Xiangyou 15 seeds than in 854-1. The promoter region sequences of Bnhol34 were then isolated from Xiangyou 15 and 854-1, and a 93-bp deletion was found to occur in the Bnhol34 promoter region of 854-1. Three abscisic acid-responsive cis-elements （ABRE） were identified in the promoter region of Xiangyou 15. Real-time PCR analyses revealed that exogenous abscisic acid increased Bnhol34 expression by about four-fold in Xiangyou 15 seeds, yet did not change Bnhol34 expression in 854-1. It appeared that Bnhol34 might be abscisic acid insensitive in 854-1.

Cloning and Characterization of Glyceraldehyde-3-phosphate Dehydrogenase Encoding Gene in Gracilaria/Gracilariopsis lemaneiformis

Glyceraldehyde-3-phosphate dehydrogenase （GAPDH） plays important roles in various cellular processes. A cytosolic GAPDH encoding gene （gpd） of Gracilaria/Gracilariopsis lemaneiformis was cloned and characterized. Deduced amino acid sequence of the enzyme of G. lemaneiformis had high homology with those of seven red algae. The 5＇-untranslated regions of the GAPDHs encoding genes of these red algae varied greatly. GAPDHs of these red algae shared the highly conserved glyceraldehyde 3-phosphate dehydrogenase active site ASCTTNCL. However, such active site of Cyanidium caldarium was different from those of the other six algae at the last two residues （CL to LF）, thus the spatial structure of its GAPDH active center may be different from those of the other six. Phylogenetic analysis indicated that GAPDH of G. lemaneiformis might have undergone an evolution similar to those of Porphyra yezoensis, Chondrus crispus, and Gracilaria verrucosa. C. caldarium had a closer evolutionary relationship with Cyanidioschyzon merolae than with Cyanidium sp. Virtual Northern blot analysis revealed that gpd of G. lemaneiformis expressed constitutively, which suggested that it might be house-keeping and could be adapted as an inner control in gene expression analysis of G. lemaneiformis.

A New Farnesyl Diphosphate Synthase Gene from Taxus media Rehder:Cloning,Characterization and Functional Complementation

Farnesyl dlphosphate synthase （FPS; EC 2.5.1.10） catalyzes the production of 15-carbon farnesyl dlphosphate which Is a branch-point Intermediate for many terpenoids. This reaction Is considered to be a ratelimiting step In terpenold biosynthesis. Here we report for the first time the cloning of a new full-length cDNA encoding farnesyl dlphosphate synthase from a gymnosperm plant species, Taxus media Rehder, designated as TmFPS1. The full-length cDNA of TmFPS1 （GenBank accession number： AY461811） was 1 464 bp with a 1 056-bp open reading frame encoding a 351-amino acid polypeptlde with a calculated molecular weight of 40.3 kDa and a theoretical pl of 5.07. Biolnformatlc analysis revealed that TmFPS1 contained all five conserved domains of prenyltransferases, and showed homology to other FPSs of plant origin. Phylogenetlc analysis showed that farnesyl dlphosphate synthases can be divided Into two groups： one of prokaryotic origin and the other of eukaryotic origin. TmFPS1 was grouped with FPSs of plant origin. Homologybased structural modeling showed that TmFPS1 had the typical spatial structure of FPS, whose most prominent structural feature Is the arrangement of 13 core helices around a large central cavity In which the catalytic reaction takes place. Our blolnformatic analysis strongly suggests that TmFPS1 is a functional gene. Southern blot analysis revealed that TmFPS1 belongs to a small FPSgene family in T. media. Northern blot analysis indicated that TmFPS1 is expressed in all tested tissues, Including the needles, stems and roots of T. media. Subsequently, functional complementatlon with TmFPS1 in a FPS-deflclent mutant yeast demonstrated that TmFPS1 did encode farnesyl dlphosphate synthase, which rescued the yeast mutant. This study will be helpful In future Investigations aiming at understanding the detailed role of FPS In terpenold biosynthesis flux control at the molecular genetic level.