Exploration of cross-cultivar group characteristics of a new cultivar of Prunus mume 'Zhizhang Guhong Chongcui' / 生物工程学报

'Zhizhang Guhong Chongcui' is a new cultivar of Prunus mume with cross-cultivar group characteristics. It has typical characteristics of cinnabar purple cultivar group and green calyx cultivar group. It has green calyx, white flower, and light purple xylem, but the mechanism remains unclear. In order to clarify the causes of its cross-cultivar group traits, the color phenotype, anthocyanin content and the expression levels of genes related to anthocyanin synthesis pathway of 'Zhizhang Guhong Chongcui', 'Yuxi Zhusha' and 'Yuxi Bian Lü'e' were determined. It was found that the red degree of petals, sepals and fresh xylem in branches was positively correlated with the total anthocyanin content. MYBɑ1, MYB1, and bHLH3 were the key transcription factor genes that affected the redness of the three cultivars of flowers and xylem. The transcription factors further promoted the high expression of structural genes F3'H, DFR, ANS and UFGT, thereby promoting the production of red traits. Combined with phenotype, anthocyanin content and qRT-PCR results, it was speculated that the white color of petals of 'Zhizhang Guhong Chongcui' were derived from the high expression of FLS, F3'5'H, LAR and ANR genes in other branches of cyanidin synthesis pathway, and the low expression of GST gene. The green color of sepals might be originated from the relatively low expression of F3'H, DFR and ANS genes. The red color of xylem might be derived from the high expression of ANS and UFGT genes. This study made a preliminary explanation for the characteristics of the cross-cultivar group of 'Zhizhang Guhong Chongcui', and provided a reference for molecular breeding of flower color and xylem color of Prunus mume.

Bovine TMEM95 gene: Polymorphisms detecting in five Chinese indigenous cattle breeds and their association with growth traits

BACKGROUND: Transmembrane protein 95 (TMEM95) plays a role in male fertility. Previous studies showed that genes with a significant impact on reproductive traits can also affect the growth traits of livestock. Thus, we speculated that the genetic variation of TMEM95 gene may have effects on growth traits of cattle. RESULTS: Two SNPs were genotyped. The rs136174626 and rs41904693 were in the intron 4 and 30 -untranslated region, respectively. The linkage disequilibrium analysis illustrated that these two loci were not linked. The rs136174626 was associated with six growth traits of Nanyang cattle, four traits of Luxi cattle, and three traits of Ji'an cattle. For rs41904693 locus, the GG individuals had greater body height and abdominal girth in Ji' an cattle than TT and TG individuals. In Jinnan cattle, GG and TT individuals had greater body height, height at hip cross, body length, and heart girth than TG individuals. The potential splice site prediction results suggest that the rs136174626 may influence the splicing efficiency of TMEM95, and the miRNA binding site prediction results showed that the rs41904693 may influence the expression of TMEM95 by affecting the binding efficiency of Bta-miR-1584 and TMEM95 30 -UTR. CONCLUSIONS: The findings of the study suggested that the two SNPs in TMEM95 could be a reliable basis for molecular breeding in cattle.

Development direction of molecular breeding of medicinal plants / 中国中药杂志

To breed new varieties of medicinal plants with high resistance is the premise to ensure the production of high-quality medicinal materials. Molecular breeding using modern molecular biology and genetic technology can save time and effort and realize rapid and accurate breeding. Here we are trying to summarize the difference of breeding characteristics between medicinal plants and crops such as genetic background and breeding purpose. The strategy of molecular breeding of medicinal plants was summarized, and the four-phases breeding based on high-throughput sequencing and target gene mining was emphasized. We put forward the current molecular breeding of medicinal plants in the condition of four phases breeding is the optimal technological way of breeding, and gene editing breeding is the direction of medicinal plants breeding.

From Basic Research to Molecular Breeding - Chinese Scientists Play A Central Role in Boosting World Rice Production / 基因组蛋白质组与生物信息学报·英文版

On November 18, 2018, the Future Science Prize Awarding Ceremony was held in Beijing. In the area of life science, Professors Jiayang Li, Longping Yuan, and Qifa Zhang shared the prize for their pioneering contributions in producing high-yield, superior-quality rice through systematic study of molecular mechanisms associated with specific rice features and application of novel approaches in rice breeding. The Future Science Prize is also touted as "China's Nobel Prize", fully affirming their achievements in rice basic research and breeding.

Differential proteomics research of Bacillus amyloliquefaciens and its genome-shuffled saltant for improving fengycin production

Abstract In the previous study, we used genome shuffling to improve fengycin production of the original strain Bacillus amyloliquefaciens ES-2-4. After two rounds of genome shuffling, a high-yield recombinant FMB72 strain that exhibited 8.30-fold increase in fengycin production was obtained. In this study, comparative proteomic analysis of the parental ES-2-4 and genome-shuffled FMB72 strains was conducted to examine the differentially expressed proteins. In the shuffled strain FMB72, 50 differently expressed spots (p < 0.05) were selected to be excised and analyzed using Matrix-Assisted Laser Desorption/Ionization Time of Flight/Time of Flight Mass Spectrometry, and finally 44 protein spots were confidently identified according to NCBI database. According to clusters of orthologous groups (COG) functional category analysis and related references, the differentially expressed proteins could be classified into several functional categories, including proteins involved in metabolism, energy generation and conversion, DNA replication, transcription, translation, ribosomal structure and biogenesis, cell motility and secretion, signal transduction mechanisms, general function prediction. Of the 44 identified proteins, signaling proteins ComA and Spo0A may positively regulate fengycin synthesis at transcriptional level. Taken together, the present study will be informative for exploring the exact roles of ComA and Spo0A in fengycin synthesis and explaining the molecular mechanism of fengycin synthesis.

Engineering of Anti-CD133 Trispecific Molecule Capable of Inducing NK Expansion and Driving Antibody-Dependent Cell-Mediated Cytotoxicity / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The selective elimination of cancer stem cells (CSCs) in tumor patients is a crucial goal because CSCs cause drug refractory relapse. To improve the current conventional bispecific immune-engager platform, a 16133 bispecific natural killer (NK) cell engager (BiKE), consisting of scFvs binding FcγRIII (CD16) on NK cells and CD133 on carcinoma cells, was first synthesized and a modified interleukin (IL)-15 crosslinker capable of stimulating NK effector cells was introduced. MATERIALS AND METHODS: DNA shuffling and ligation techniques were used to assemble and synthesize the 1615133 trispecific NK cell engager (TriKE). The construct was tested for its specificity using flow cytometry, cytotoxic determinations using chromium release assays, and lytic degranulation. IL-15–mediated expansion was measured using flow-based proliferation assays. The level of interferon (IFN)-γ release was measured because of its importance in the anti-cancer response. RESULTS: 1615133 TriKE induced NK cell–mediated cytotoxicity and NK expansion far greater than that achieved with BiKE devoid of IL-15. The drug binding and induction of cytotoxic degranulation was CD133+ specific and the anti-cancer activity was improved by integrating the IL-15 cross linker. The NK cell–related cytokine release measured by IFN-γ detection was higher than that of BiKE. NK cytokine release studies showed that although the IFN-γ levels were elevated, they did not approach the levels achieved with IL-12/IL-18, indicating that release was not at the supraphysiologic level. CONCLUSION: 1615133 TriKE enhances the NK cell anti-cancer activity and provides a self-sustaining mechanism via IL-15 signaling. By improving the NK cell performance, the new TriKE represents a highly active drug against drug refractory relapse mediated by CSCs.

Thermotolerant fermenting yeasts for simultaneous saccharification fermentation of lignocellulosic biomass

Lignocellulosic biomass is the most abundant renewable source of energy that has been widely explored as second-generation biofuel feedstock. Despite more than four decades of research, the process of ethanol production from lignocellulosic (LC) biomass remains economically unfeasible. This is due to the high cost of enzymes, end-product inhibition of enzymes, and the need for cost-intensive inputs associated with a separate hydrolysis and fermentation (SHF) process. Thermotolerant yeast strains that can undergo fermentation at temperatures above 40°C are suitable alternatives for developing the simultaneous saccharification and fermentation (SSF) process to overcome the limitations of SHF. This review describes the various approaches to screen and develop thermotolerant yeasts via genetic and metabolic engineering. The advantages and limitations of SSF at high temperatures are also discussed. A critical insight into the effect of high temperatures on yeast morphology and physiology is also included. This can improve our understanding of the development of thermotolerant yeast amenable to the SSF process to make LC ethanol production commercially viable.

Regulation of global transcriptional factor cyclic AMP receptor protein and its metabolic engineering application in Escherichia coli / 生物工程学报

Cyclic amp receptor protein (CRP) is a global transcriptional factor in many prokaryotes, capable of governing nearly half of the total genes in Escherichia coli. Through the method of error-prone PCR or DNA shuffling, we can first obtain CRP mutant library and then get the expected cell phenotype with enhanced resistance. In this article, we reviewed the following desired phenotype: enhanced tolerance towards oxidative stress, improved osmotolerance, enhanced organic solvent (toluene) tolerance, improved acetate tolerance of E. coli fermentation and improved ethanol tolerance during bio-ethanol production. We then concluded that CRP can also be applied in other host cells to get desired phenotypes. Last, we predicted potential applications of mutant CRP transcriptional factor.

Genome shuffling method of Bacillus subtilis / 生物工程学报

Genome shuffling methods were explored for Bacillus subtilis strain molecular breeding. Recycling protoplast fusion, recycling transformation and recycling universal transduction were used for genome shuffling in B. subtilis. Four strains with different nutrition-deficiency markers were used as initial strains. After five rounds protoplast fusion, transformation or transduction, the descendant with 4 markers had not been detected, and the rate of descendant with 3 markers were 4.53 x 10(-4), 1.64 x 10(-4), 4.47 x 10(-3), respectively. A computer program was made to simulate the recycling fusion process. Based on simulation result and comparing the genome shuffling result of B. subtilis in this experiment and that of Streptomyces coelicolor reported in references, effective genome shuffling needs a high recombination rate of at least between 10(-3) and 10(-2).

Novel methods and strategies for strain improvement / 生物工程学报

Improvement of the productivity of industrial strains is an important field in micro-biology, because wild-type strains isolated from nature usually produce only a low level of antibiotics. Although random screening and simple rational screening are still effective without using genomic information, they are always time- and labor-consuming. With the broad application of recombinant DNA technology, protoplast fusion and X-omics, novel methods and strategies such as metabolic engineering, genome shuffling, system biology and system biotechnology, ribosome engineering, epigenetic modification are being exploited for the industry microbiology. In this review, we will focus on the progress of these novel methods and strategies for strain improvement in recent years.

Directed molecular evolution of nitrite oxido-reductase by DNA-shuffling / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop directly molecular evolution of nitrite oxido-reductase using DNA-shuffling technique because nitrobacteria grow extremely slow and are unable to nitrify effectively inorganic nitrogen in wastewater treatment.</p><p><b>METHODS</b>The norB gene coding the ndtrite oxido-reductase in nitrobacteria was cloned and sequenced. Then, directed molecular evolution of nitrite oxido-reductase was developed by DNA-shuffling of 15 norB genes from different nitrobacteria.</p><p><b>RESULTS</b>After DNA-shuffling with sexual PCR and staggered extension process PCR, the sequence was different from its parental DNA fragments and the homology ranged from 98% to 99%. The maximum nitrification rate of the modified bacterium of X16 by DNA-shuffling was up to 42.9 mg/L x d, which was almost 10 times higher than that of its parental bacteria. Furthermore, the modified bacterium had the same characteristics of its parental bacteria of E. coli and could grow rapidly in normal cultures.</p><p><b>CONCLUSION</b>DNA-shuffling was successfully used to engineer E. coli, which had norB gene and could degrade inorganic nitrogen effectively.</p>

Rapid improvement of lipase production in Penicillium expansum by genome shuffling / 生物工程学报

In the present study, the genome shuffling was used to improve lipase production of Penicillium expansum. A lipase producing mutant strain-Penicillium expansum FS8486 and a wild type of Aspergillus Tamarii FS-132 isolated from soil of a volcano in Xinjiang were used as the parental strains. After two rounds of genome shuffling, several elite daughter strains were screened. The lipase activity in one of the daughter strains was increased 317% over the starting strain FS8486. Comparisons of the morphology, RAPD (Random Amplification of Polymorphic DNA) polymorphism and the fatty acid compositions between the daughter and the parental strains suggested that the filial generation were generated by genome shuffling. In this study, the genome shuffling used successfully first time in eukaryotic microorganism and increases the production of the desired metabolite in short time, the study will be useful to spread the genome shuffling in eukaryotic microbial breeding.

Easy approach to DNA shuffling: its potential implication in health sciences.

Directed evolution experiments rely on the cyclical application of mutagenesis, screening and amplifications in a test tube. During the laboratory evolution of biological molecules, recombination has been used to generate novel sequences in a process known as DNA shuffling. DNA shuffling is a recently developed technique that allows accelerated and directed protein evolution for desired properties in vitro, which recombines and evolves genes to rapidly obtain molecules with improved biological activity and fitness. DNA shuffling is generally achieved by DNaseI treatment and by PCR. This has led to the creation of novel proteins for a wide range of applications. The use of improved enzymes for medical, industrial and environmental purposes is prevalent today, and will be expanding. New applications in vaccine development and disease diagnosis are among the key features of DNA shuffling. However, directed evolution currently requires an uncertain, typically large number of labor-intensive and expensive experimental cycles before proteins with improved function are identified. A simplified and low-cost DNA shuffling protocol for random recombination of homologous genes in vitro is described here.

Directed evolution of D-lactonohydrolase by error prone PCR and DNA shuffling / 生物工程学报

D-lactonohydrolase is useful in the procedure of resolution of racemic pantolactone to produce D-pantolactone, but the activity and stability under low pH of the wild type enzyme is not satisfactory enough to be applied to industrial production. The expected properties of wild type enzyme were enhanced by directed evolution. According to the formation of products and pH indicators, a screening system was designed. After three sequential error prone PCR and one round DNA shuffling followed by screening, Mut E-861, the best mutant with improved activity and stability under low pH situation was obtained. Gene analysis of the Mut E-861 mutant indicated that the mutant enzyme had A352C, G721A mutations and a silent mutation of position 1038. Moreover, the activity and stability of Mut E-861 were determined. The results showed that the activity of this mutant was 5.5-fold higher than that of wild type, and the stability under low pH was improved at no expense of D-lactonohydrolase activity. After incubated at pH 6.0 and pH 5.0 the activity of D-lactonohydrolase could be retained 75% to 50%, however, compared with 40% to 20% for wild type.

Combined Genome Mapping of RFLP-AFLP-SSR in Pepper

We have constructed a molecular linkage map of pepper (Capsicum spp.) in an interspecific F2 population of 107 plants with 320 RFLP, 136 AFLP, and 46 SSR markers. The resulting linkage map consists of 15 linkage groups covering 1,720 cM with an average map distance of 3.7 cM between framework markers. Most RFLP markers (80%) were pepper-derived clones and these markers were evenly distributed all over the genome. Genes for defense and biosynthesis of carotenoids and capsaicinoids were mapped on this linkage map. By using 30 primer combinations, AFLP markers were generated in the F2 population. For development of SSR markers in Capsicum, microsatellites were isolated from two small-insert genomic libraries and the GenBank database. This combined map provides a starting point for high-resolution QTL analysis, gene isolation, and molecular breeding.