Description: Background: Chinese fir (Cunninghamia lanceolata) is an important timber species that accounts for 20--30% of the total commercial timber production in China. However, the available genomic information of Chinese fir is limited, and this severely encumbers functional genomic analysis and molecular breeding in Chinese fir. Recently, major advances in transcriptome sequencing have provided fast and cost-effective approaches to generate large expression datasets that have proven to be powerful tools to profile the transcriptomes of non-model organisms with undetermined genomes. Results: In this study, the transcriptomes of nine tissues from Chinese fir were analyzed using the Illumina HiSeqTM 2000 sequencing platform. Approximately 40 million paired-end reads were obtained, generating 3.62 gigabase pairs of sequencing data. These reads were assembled into 83,248 unique sequences (i.e. Unigenes) with an average length of 449 bp, amounting to 37.40 Mb. A total of 73,779 Unigenes were supported by more than 5 reads, 42,663 (57.83%) had homologs in the NCBI non-redundant and Swiss-Prot protein databases, corresponding to 27,224 unique protein entries. Of these Unigenes, 16,750 were assigned to Gene Ontology classes, and 14,877 were clustered into orthologous groups. A total of 21,689 (29.40%) were mapped to 119 pathways by BLAST comparison against the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The majority of the genes encoding the enzymes in the biosynthetic pathways of cellulose and lignin were identified in the Unigene dataset by targeted searches of their annotations. And a number of candidate Chinese fir genes in the two metabolic pathways were discovered firstly. Eighteen genes related to cellulose and lignin biosynthesis were cloned for experimental validating of transcriptome data. Overall 49 Unigenes, covering different regions of these selected genes, were found by alignment. Their expression patterns in different tissues were analyzed by qRT-PCR to explore their putative functions. Conclusions: A substantial fraction of transcript sequences was obtained from the deep sequencing of Chinese fir. The assembled Unigene dataset was used to discover candidate genes of cellulose and lignin biosynthesis. This transcriptome dataset will provide a comprehensive sequence resource for molecular genetics research of C. lanceolata.

Description: Journal of the American Chemical Society DOI: 10.1021/ja303702n

Description: Shaanxilithes ningqiangensis is an enigmatic ribbon-shaped fossil from the upper Ediacaran Gaojiashan Member of the Dengying Formation, southern Shaanxi Province, South China. This taxon has also been reported from Ediacaran successions in North China and possibly in Siberia, making it a potential index fossil for interregional biostratigraphic correlation of upper Ediacaran successions. At Gaojiashan, Shaanxilithes ningqiangensis is often preserved along bedding planes of phosphate-rich silty and calcareous shale, with no evidence of vertical intrusion into adjacent beds and containing little to no carbonaceous material. Here, through detailed microstructural and microchemical investigation using a combination of analytical techniques, taphonomic details of Shaanxilithes ningqiangensis and potentially related forms are revealed, showing that these enigmatic fossils are preserved as clay molds. Together with other taphonomic features, such as abruptly bent ribbons, overlapping but not crosscutting ribbons, and co-occurring discoidal structures interpreted as disarticulated sections of the original organism, the new data suggest that Shaanxilithes ningqiangensis is a body fossil consisting of serially arranged units that are discoidal, lensoidal, or crescentic in shape. Shaanxilithes ningqiangensis is not a trace fossil as some previous researchers have suggested.