A joint analysis strategy reveals genetic changes associated with artificial selection between egg-type and meat-type ducks

Egg-type ducks and meat-type ducks are predominantly commercial or indigenous and have been subjected to artificial directional selection. These two duck types differ substantially in body shape, production performance and reproductivity. However, the genetic changes associated with phenotypic differences remain unclear. Here, we compared the two duck types at the genomic and transcriptomic levels. We identified a large number of SNPs and genes in genomic divergent regions in terms of F_ST and θπ values. The corresponding genes were mainly enriched in embryonic development function and metabolic pathway. RNA-seq analysis also revealed differential gene expression in the liver and gonads. The differentially expressed genes were functionally associated with signal transmission and substance metabolism respectively. Furthermore, we found that seven genes were related to differentiation between the two types by both g genome and transcriptome analysis and were plausible candidate genes. These genes were annotated to GO categories of cell development and disease immunity. These findings will enable a better understanding of the artificial selection history of meat and egg ducks and provide a valuable resource for future research on the breeding of these two lineages.

High-fidelity SaCas9 identified by directional screening in human cells

CRISPR-Staphylococcus aureus Cas9 (CRISPR-SaCas9) has been harnessed as an effective in vivo genome-editing tool to manipulate genomes. However, off-target effects remain a major bottleneck that precludes safe and reliable applications in genome editing. Here, we characterize the off-target effects of wild-type (WT) SaCas9 at single-nucleotide (single-nt) resolution and describe a directional screening system to identify novel SaCas9 variants with desired properties in human cells. Using this system, we identified enhanced-fidelity SaCas9 (efSaCas9) (variant Mut268 harboring the single mutation of N260D), which could effectively distinguish and reject single base-pair mismatches. We demonstrate dramatically reduced off-target effects (approximately 2- to 93-fold improvements) of Mut268 compared to WT using targeted deep-sequencing analyses. To understand the structural origin of the fidelity enhancement, we find that N260, located in the REC3 domain, orchestrates an extensive network of contacts between REC3 and the guide RNA-DNA heteroduplex. efSaCas9 can be broadly used in genome-editing applications that require high fidelity. Furthermore, this study provides a general strategy to rapidly evolve other desired CRISPR-Cas9 traits besides enhanced fidelity, to expand the utility of the CRISPR toolkit.

Identification of genetic effects and potential causal polymorphisms of CPM gene impacting milk fatty acid traits in Chinese Holstein

Our previous GWAS revealed 83 significant SNPs and 20 promising candidate genes associated with milk fatty acid traits in dairy cattle. Out of them, the carboxypeptidase M (CPM) gene contains a genome-wide significant SNP, Hapmap49848-BTA-106779, which is strongly associated with myristic acid (C14:0; P = 0.0064). Herein, we aimed to confirm the genetic effects of CPM on milk fatty acids in Chinese Holstein. Seven SNPs were detected by re-sequencing the sequences of entire exons and 3000 bp of up-/downstream flanking regions of the CPM gene, of which three were in 5' flanking region, one in the 3' UTR and three were in the 3' flanking region. Using the Haploview 4.1, we estimated the LD among the identified SNPs and found two haplotype blocks. With the animal model, we performed the SNP- and haplotype-based association analyses, and observed that these SNPs and haplotype blocks mainly had strong genetic associations with medium-chain saturated fatty acids (caproic acid, C6:0; caprylic acid, C8:0; capric acid, C10:0; and lauric acid, C12:0) (P < 0.0001-0.0257). In addition, using the Genomatix software, we predicted that three SNPs in the 5' flanking region of CPM (g.45079507A>G, g.45080228C>A and g.45080335C>G) changed the transcription factor binding sites for PREF (progesterone receptor biding site), ZBRK1 (transcription factor with eight central zinc fingers and an N-terminal KRAB domain), SOX9 (sex-determining region Y-box 9, dimeric binding sites), SOX6 (sex-determining region Y-box 6) and FOXP1-ES (alternative splicing variant of FOXP1, activated in ESCs). Further, the dual-luciferase reporter assay showed these three SNPs altered the transcriptional activity of CPM gene (P ≤ 0.0006). In summary, using the post-GWAS strategy, we first confirmed the significant genetic effects of CPM with milk fatty acids in dairy cattle, and identified three potential causal mutations.

Calycosin enhances the bactericidal efficacy of polymyxin B by inhibiting MCR-1 in vitro

AIM

To examine the synergistic effect of calycosin combined with polymyxin B against various mcr-1-positive bacterial strains.

METHODS AND RESULTS

In this study, we found a potential inhibitor of MCR-1, calycosin, that could significantly restore the antibacterial activity of polymyxin B. The synergistic effect of calycosin combined with polymyxin B against various mcr-1-positive bacterial strains was confirmed by checkerboard minimum inhibitory concentration assays, time-kill curve assays and disk diffusion assays. The fractional inhibitory concentration indexes ranged from 0·15 ± 0·03 to 0·28 ± 0·05, and the zones of inhibition increased from 13·33 ± 0·47 to 17·67 ± 0·47 mm with the combined therapy of calycosin and polymyxin B. In addition, the combined therapy significantly reduced the number of bacteria in the medium. However, at the concentrations required for the synergistic effect with polymyxin B, calycosin alone showed no effect on bacterial growth or MCR-1 production. Calycosin treatment exhibited no cytotoxicity to HeLa cells or A549 cells at calycosin concentrations below 32 µg ml^-1 .

CONCLUSIONS

Therefore, our results suggested that calycosin could be used as a potential MCR-1 inhibitor to restore the bactericidal effect of polymyxin B without affecting bacterial viability or existing cytotoxicity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The synergistic effect of calycosin combined with polymyxin B against various mcr-1-positive bacterial strains paves the way for future pharmaceutical applications of calycosin in fighting mcr-1-positive bacterial infections.

Development of a Simple and Quick Method to Assess Base Editing in Human Cells

Base editing is a form of genome editing that can directly convert a single base (C or A) to another base (T or G), which is of great potential in biomedical applications. The broad application of base editing is limited by its low activity and specificity, which still needs to be resolved. To address this, a simple and quick method for the determination of its activity/specificity is highly desired. Here, we developed a novel system, which could be harnessed for quick detection of editing activity and specificity of base editors (BEs) in human cells. Specifically, multiple cloning sites (MCS) were inserted into the human genome via lentivirus, and base editing targeting the MCS was performed with BEs. The base editing activities were assessed by specific restriction enzymes. The whole process only includes nucleotide-based targeting the MCS, editing, PCR, and digestion, thus, we named it NOTEPAD. This straightforward approach could be easily accessed by molecular biology laboratories. With this method, we could easily determine the BEs editing efficiency and pattern. The results revealed that BEs triggered more off-target effects in the genome than on plasmids including genomic indels (insertions and deletions). We found that ABEs (adenine base editors) had better fidelity than CBEs (cytosine base editors). Our system could be harnessed as a base editing assessment platform, which would pave the way for the development of next-generation BEs.

MiR-1203 is involved in hepatocellular carcinoma metastases and indicates a poor prognosis

Non-coding RNAs, especially miRNAs, have been shown to be important regulators in multiple human diseases, including malignant tumors, congenital disease, and autoimmune disease. In this study, we screened the metastasis-associated miRNAs in hepatocellular carcinoma (HCC). Based on the miRNA microarray screening, miR-1203 was confirmed to be the most significant miRNA and was also highly associated with HCC metastases. Bioinformatics prediction indicated direct binding of miR-1203 in SOCS3, which was also confirmed by a dual luciferase reporter assay, resulting in suppression of SOCS3. Increased miR-1203 also promoted invasion of HCC cells through suppressing SOCS3, while no effect on cell proliferation or apoptosis was detected. Circulating expression of miR-1203 and SOCS3 might serve as a predictor of metastases and poor prognosis in HCC patients. In conclusion, miR-1203 might promote HCC metastasis by decreasing SOCS3. MiR-1203 predicts a poor outcome in HCC patients and thus might serve as a potential therapeutic target for the prevention of HCC.

MicroRNA-520a-3p suppresses non-small-cell lung carcinoma by inhibition of High Mobility Group Box 1 (HMGB1)

OBJECTIVE

Currently, pathogenesis of non-small cell lung carcinoma (NSCLC) is still unknown and the treatment is far from ideal. Therefore, we investigated the effect of inhibiting microRNA-520a-3p in NSCLC cells.

MATERIALS AND METHODS

NCI-H157 cells were treated with microRNA-520a-3p analogs for 48 h, or microRNA-520a-3p analogs and its inhibitor, for a total of 48 h. Many tests were performed, including MTT, flow cytometry, wound healing assay and transwell assay. The tumor model was established, and HMGB1 mRNA was detected by RT-PCR. Protein levels of HMGB1, MMP-2, MMP-9, Bcl-2, Bax, and Caspase-3 were assessed by Western Blot.

RESULTS

microRNA-520a-3p could significantly inhibit the proliferation, migration and invasion of NCI-H157 cells, inducing their apoptosis. microRNA-520a-3p inhibited tumor growth and decreased the mRNA and protein levels of HMGB1. Additionally, it decreased the Bcl-2/Bax ratio, MMP-2 and MMP-9 expression, and increased caspase-3 expression.

CONCLUSIONS

microRNA-520a-3p exhibited an effective inhibition on NCI-H157 tumor growth likely by inhibiting HMGB1 expression.

Hyperpolarized relaxometry based nuclear T1 noise spectroscopy in diamond

The origins of spin lifetimes in quantum systems is a matter of importance in several areas of quantum information. Spectrally mapping spin relaxation processes provides insight into their origin and motivates methods to mitigate them. In this paper, we map nuclear relaxation in a prototypical system of [Formula: see text] nuclei in diamond coupled to Nitrogen Vacancy (NV) centers over a wide field range (1 mT-7 T). Nuclear hyperpolarization through optically pumped NV electrons allows signal measurement savings exceeding million-fold over conventional methods. Through a systematic study with varying substitutional electron (P1 center) and [Formula: see text] concentrations, we identify the operational relaxation channels for the nuclei at different fields as well as the dominant role played by [Formula: see text] coupling to the interacting P1 electronic spin bath. These results motivate quantum control techniques for dissipation engineering to boost spin lifetimes in diamond, with applications including engineered quantum memories and hyperpolarized [Formula: see text] imaging.

MicroRNA-520a-3p inhibits cell growth and metastasis of non-small cell lung cancer through PI3K/AKT/mTOR signaling pathway

OBJECTIVE

MicroRNAs are a class of small non-coding RNAs that be involved in the pathogenesis of non-small cell lung cancer (NSCLC). The purpose of this study was to evaluate the effects of miR-520a-3p in cell growth and metastasis.

MATERIALS AND METHODS

The mimics and inhibitor of miR-520a-3p were used to identify the effects of miR-520a-3p on cell proliferation and apoptosis using methylthiazol tetrazolium (MTT) assay and flow-cytometric method, respectively. Transwell assay was used to evaluate the cell migration and invasion. The protein expression levels related PI3K/AKT/mTOR signaling pathways were measured by Western blot.

RESULTS

The results showed that miR-520a-3p overexpression could significantly inhibit cell proliferation and induce apoptosis, suppress cell migration and invasion. MiR-520a-3p overexpression could markedly reduce the ratio of p-AKT/AKT, p-PI3K/PI3K and Bcl-2/Bax, the levels of mTOR, matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) compared with control. However, miR-520a-3p overexpression could increase caspase-3 expression compared with control group. After inhibited the expression of miR-520a-3p, the capacity of cell proliferation, migration and invasion were increased, cell apoptosis was inhibited compared with control group. The ratio of p-AKT/AKT, p-PI3K/PI3K and Bcl-2/Bax, the levels of mTOR, MMP-2 and MMP-9 were increased compared with control group.

CONCLUSIONS

Our study suggested that miR-520a-3p could suppress the NSCLC proliferation, migration and invasion through PI3K/AKT/mTOR signaling pathway.

Identification of genetic associations of ECHS1 gene with milk fatty acid traits in dairy cattle

Our previous genome-wide association study identified 83 genome-wide significant SNPs and 20 novel promising candidate genes for milk fatty acids in Chinese Holstein. Among them, the enoyl-CoA hydratase, short chain 1 (ECHS1) and enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase (EHHADH) genes were located near two SNPs and one SNP respectively, and they play important roles in fatty acid metabolism pathways. We herein validated whether the two genes have genetic effects on milk fatty acid traits in dairy cattle. By re-sequencing the full-length coding region, partially adjacent introns and 3000 bp up/downstream flanking sequences, we identified 12 SNPs in ECHS1: two in exons, four in the 3' flanking region and six in introns. The g.25858322C>T SNP results in an amino acid replacement from leucine to phenylalanine and changes the secondary structure of the ECHS1 protein, and single-locus association analysis showed that it was significantly associated with three milk fatty acids (P = 0.0002-0.0013). The remaining 11 SNPs were found to be significantly associated with at least one milk fatty acid (P = <0.0001-0.0040). Also, we found that two haplotype blocks, consisting of nine and two SNPs respectively, were significantly associated with eight milk fatty acids (P = <0.0001-0.0125). However, none of polymorphisms was observed in the EHHADH gene. In conclusion, our findings are the first to indicate that the ECHS1 gene has a significant genetic impact on long-chain unsaturated and medium-chain saturated fatty acid traits in dairy cattle, although the biological mechanism is still undetermined and requires further in-depth validation.

Comparison of microRNAs in adipose and muscle tissue from seven indigenous Chinese breeds and Yorkshire pigs

Elucidation of the pig microRNAome is essential for interpreting functional elements of the genome and understanding the genetic architecture of complex traits. Here, we extracted small RNAs from skeletal muscle and adipose tissue, and we compared their expression levels between one Western breed (Yorkshire) and seven indigenous Chinese breeds. We detected the expression of 172 known porcine microRNAs (miRNAs) and 181 novel miRNAs. Differential expression analysis found 92 and 12 differentially expressed miRNAs in adipose and muscle tissue respectively. We found that different Chinese breeds shared common directional miRNA expression changes compared to Yorkshire pigs. Some miRNAs differentially expressed across multiple Chinese breeds, including ssc-miR-129-5p, ssc-miR-30 and ssc-miR-150, are involved in adipose tissue function. Functional enrichment analysis revealed that the target genes of the differentially expressed miRNAs are associated mainly with signaling pathways rather than metabolic and biosynthetic processes. The miRNA-target gene and miRNA-phenotypic traits networks identified many hub miRNAs that regulate a large number of target genes or phenotypic traits. Specifically, we found that intramuscular fat content is regulated by the greatest number of miRNAs in muscle tissue. This study provides valuable new candidate miRNAs that will aid in the improvement of meat quality and production.

Clinical significance of epithelial-mesenchymal transition-related molecules in lung adenocarcinoma

Background

Epithelial-mesenchymal transition (emt) refers to the biologic process in which epithelial cells are transformed into interstitial phenotypes by specific pathways. This transition plays an important biologic role in the process by which epithelium-derived malignant tumour cells acquire the ability to migrate and invade. We explored the relationship between emt-associated molecules and patient-related clinical factors to determine whether any clinical characteristics could be used as biomarkers for emt-related protein alterations in lung cancer-especially lung adenocarcinoma.

Methods

Tumour specimens were collected from 80 patients with lung adenocarcinoma who underwent surgery or lung biopsy, with 4 patients being evaluated a 2nd time after re-biopsy. Expression of emt-related proteins, including E-cadherin and vimentin, was evaluated by immunohistochemistry. We analyzed the relationship between clinicopathologic characteristics and expression level of the emt markers.

Results

Positive expression of E-cadherin was observed in 63 patients (79%), and vimentin, in 46 patients (57.5%). No significant relationships between E-cadherin or vimentin expression and smoking history, sex, age, driving gene mutations, or cell differentiation were identified. A significant correlation was observed between vimentin expression and pathologic stage. Of the 4 patients who were evaluated a 2nd time after re-biopsy, 3 showed the same emt-related protein expression status as in the first analysis. In the remaining patient, E-cadherin had changed completely.

Conclusions

Clinicopathologic factors in cancer patients did not help to diagnose emt status in lung adenocarcinoma; however, TNM stage might be associated with vimentin expression.

Wide dynamic range magnetic field cycler: Harnessing quantum control at low and high fields

We describe the construction of a fast field cycling device capable of sweeping a 4-order-of-magnitude range of magnetic fields, from ∼1 mT to 7 T, in under 700 ms, and which is further extendable to a 1 nT-7 T range. Central to this system is a high-speed sample shuttling mechanism between a superconducting magnet and a magnetic shield, with the capability to access arbitrary fields in between with high resolution. Our instrument serves as a versatile platform to harness the inherent dichotomy of spin dynamics on offer at low and high fields-in particular, the low anisotropy, fast spin manipulation, and rapid entanglement growth at low field as well as the long spin lifetimes, spin specific control, and efficient inductive measurement possible at high fields. Exploiting these complementary capabilities in a single device opens up applications in a host of problems in quantum control, sensing, and information storage, besides in nuclear hyperpolarization, relaxometry, and imaging. In particular, in this paper, we focus on the ability of the device to enable low-field hyperpolarization of ¹³C nuclei in diamond via optically pumped electronic spins associated with nitrogen vacancy defect centers.