The chloroplast trnT-trnF region in the seed plant lineage Gnetales

Gnetum chinense, a new species of Gnetaceae from southwestern China

Gnetum chinense sp. nov., a new lianoid species of Gnetaceae, is described from southwestern China. The new species is morphologically similar to G. montanum Markgr. in its oblong elliptic leaves and the ovoid to ellipsoid chlamydosperm, but differs from the latter by its shorter male spikes having fewer involucral collars (7-10 vs. 13-18 in G. montanum). We also did a new molecular analysis using one nuclear marker (i.e. nrITS) and four chloroplast markers (i.e. matK gene, rpoC1 intron, psbB-rps12 IGS, and trnF-trnV IGS). The result suggests that this specific clade is sister to a large clade consisting of all other known Chinese lianoid species of Gnetum except G. parvifolium (Warb.) W.C. Cheng.

The complete chloroplast genome of Gnetum montanum and sequence analysis

The complete chloroplast sequence of Gnetum montanum (GenBank accession number: NC_021438.1) was determined and characterized in this study. The size of the chloroplast genome of Gnetum montanum is 115 019 bp. Including a large single copy (LSC) region of 66 697 bp and a small single copy (SSC) region of 9494 bp separated by a pair of identical inverted repeat regions (IRs) of 19 414 bp each. A total of 108 genes that were successfully annotated contains 65 protein-coding genes, 40 tRNA genes and 3 rRNA genes. The GC content of the chloroplast genome of Gnetum montanum is 38.16%. Twelve genes contain one introns.

Molecular identification of Mango, Mangifera indica L.var. totupura

Mango (>Mangifera indica) belonging to Anacardiaceae family is a fruit that grows in tropical regions. It is considered as the King of fruits. The present work was taken up to identify a tool in identifying the mango species at the molecular level. The chloroplast trnL-F region was amplified from extracted total genomic DNA using the polymerase chain reaction (PCR) and sequenced. Sequence of the dominant DGGE band revealed that Mangifera indica in tested leaves was Mangifera indica (100% similarity to the ITS sequences of Mangifera indica). This sequence was deposited in NCBI with the accession no. GQ927757.

GISSD: Group I Intron Sequence and Structure Database

Group I Intron Sequence and Structure Database (GISSD) is a specialized and comprehensive database for group I introns, focusing on the integration of useful group I intron information from available databases and providing de novo data that is essential for understanding these introns at a systematic level. This database presents 1789 complete intron records, including the nucleotide sequence of each annotated intron plus 15 nt of the upstream and downstream exons, and the pseudoknots-containing secondary structures predicted by integrating comparative sequence analyses and minimal free energy algorithms. These introns represent all 14 subgroups, with their structure-based alignments being separately provided. Both structure predictions and alignments were done manually and iteratively adjusted, which yielded a reliable consensus structure for each subgroup. These consensus structures allowed us to judge the confidence of 20 085 group I introns previously found by the INFERNAL program and to classify them into subgroups automatically. The database provides intron-associated taxonomy information from GenBank, allowing one to view the detailed distribution of all group I introns. CDSs residing in introns and 3D structure information are also integrated if available. About 17 000 group I introns have been validated in this database; ∼95% of them belong to the IC3 subgroup and reside in the chloroplast tRNA^Leu gene. The GISSD database can be accessed at http://www.rna.whu.edu.cn/gissd/