DRDB: An Online Date Palm Genomic Resource Database.

Background: Date palm (Phoenix dactylifera L.) is a cultivated woody plant with agricultural and economic importance in many countries around the world. With the advantages of next generation sequencing technologies, genome sequences for many date palm cultivars have been released recently. Short sequence repeat (SSR) and single nucleotide polymorphism (SNP) can be identified from these genomic data, and have been proven to be very useful biomarkers in plant genome analysis and breeding. Results: Here, we first improved the date palm genome assembly using 130X of HiSeq data generated in our lab. Then 246,445 SSRs (214,901 SSRs and 31,544 compound SSRs) were annotated in this genome assembly; among the SSRs, mononucleotide SSRs (58.92%) were the most abundant, followed by di- (29.92%), tri- (8.14%), tetra- (2.47%), penta- (0.36%), and hexa-nucleotide SSRs (0.19%). The high-quality PCR primer pairs were designed for most (174,497; 70.81% out of total) SSRs. We also annotated 6,375,806 SNPs with raw read depth≥3 in 90% cultivars. To further reduce false positive SNPs, we only kept 5,572,650 (87.40% out of total) SNPs with at least 20% cultivars support for downstream analyses. The high-quality PCR primer pairs were also obtained for 4,177,778 (65.53%) SNPs. We reconstructed the phylogenetic relationships among the 62 cultivars using these variants and found that they can be divided into three clusters, namely North Africa, Egypt - Sudan, and Middle East - South Asian, with Egypt - Sudan being the admixture of North Africa and Middle East - South Asian cultivars; we further confirmed these clusters using principal component analysis. Moreover, 34,346 SSRs and 4,177,778 SNPs with PCR primers were assigned to shared cultivars for cultivar classification and diversity analysis. All these SSRs, SNPs and their classification are available in our database, and can be used for cultivar identification, comparison, and molecular breeding. Conclusion:DRDB is a comprehensive genomic resource database of date palm. It can serve as a bioinformatics platform for date palm genomics, genetics, and molecular breeding. DRDB is freely available at http://drdb.big.ac.cn/home.

Proteomic Analysis of the Protein Expression Profile in the Mature Nigella sativa (Black Seed).

Nigella sativa (N. sativa) seed has been used as an important nutritional flavoring agent and in traditional medicine for treating many illnesses since ancient times. Understanding the proteomic component of the seed may lead to enhance the understanding of its structural and biological functional complexity. In this study, we have analyzed its proteome profile based on gel-based proteome mapping technique that includes one-dimensional gel electrophoresis followed by liquid chromatography and tandem mass spectrometry strategy. We have not come across any such studies that have been performed in N. sativa seeds up to date. A total of 277 proteins were identified, and their functional, metabolic, and location-wise annotations were carried out using the UniProt database. The majority of proteins identified in the proteome dataset based on their function were those involved in enzyme catalytic activity, nucleotide binding, and protein binding while the major cellular processes included regulation of biological process followed by regulation of secondary biological process, cell organization and biogenesis, protein metabolism, and transport. The identified proteome was localized mainly to the nucleus then to the cytoplasm, plasma membrane, mitochondria, plastid, and others. A majority of the proteins were involved in biochemical pathways involving carbohydrate metabolism, amino acid and shikimate pathway, lipid metabolism, nucleotide, cell organization and biogenesis, transport, and defense processes. The identified proteins in the dataset help to improve our understanding of the pathways involved in N. sativa seed metabolism and its biochemical features and detail out useful information that may help to utilize these proteins. This study could thus pave a way for future further high-throughput studies using a more targeted proteomic approach.

Molecular Modeling and Phylogeny of the Krüppel-like Factor 4 (cKLF4) Protein from the Arabian Camel, Camelus dromedarius.

Krüppel-like factor 4 (KLF4) is a pluripotency transcription factor that helps in generating induced pluripotent stem cells (iPSCs). We sequenced for the first time the full coding sequence of Camelus dromedarius KLF4 (cKLF4), which is also known as the Arabian camel. Bioinformatics analysis revealed the molecular weight and the isoelectric point of cKLF4 protein to be 53.043 kDa and 8.74, respectively. The predicted cKLF4 protein sequence shows high identity with some other species as follows: 98% with Bactrian camel and 89% with alpaca KLF4 proteins. A three-dimensional (3D) structure was built based on the available crystal structure of the Mus musculus KLF4 (mKLF4) of 82 residues (PDB: 2 WBS) and by predicting 400 residues using bioinformatics software. The comparison confirms the presence of the zinc finger domains in cKLF4 protein. Phylogenetic analysis showed that KLF4 from the Arabian camel is grouped with the Bactrian camel, alpaca, cattle, and pig. This study will help in the annotation of KLF4 protein and in generating camel-induced pluripotent stem cells (CiPSCs).