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

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)

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