OsLG3 contributing to rice grain length and yield was mined by Ho-LAMap

BACKGROUND

Most agronomic traits in rice are complex and polygenic. The identification of quantitative trait loci (QTL) for grain length is an important objective of rice genetic research and breeding programs.

RESULTS

Herein, we identified 99 QTL for grain length by GWAS based on approximately 10 million single nucleotide polymorphisms from 504 cultivated rice accessions (Oryza sativa L.), 13 of which were validated by four linkage populations and 92 were new loci for grain length. We scanned the Ho (observed heterozygosity per locus) index of coupled-parents of crosses mapping the same QTL, based on linkage and association mapping, and identified two new genes for grain length. We named this approach as Ho-LAMap. A simulation study of six known genes showed that Ho-LAMap could mine genes rapidly across a wide range of experimental variables using deep-sequencing data. We used Ho-LAMap to clone a new gene, OsLG3, as a positive regulator of grain length, which could improve rice yield without influencing grain quality. Sequencing of the promoter region in 283 rice accessions from a wide geographic range identified four haplotypes that seem to be associated with grain length. Further analysis showed that OsLG3 alleles in the indica and japonica evolved independently from distinct ancestors and low nucleotide diversity of OsLG3 in indica indicated artificial selection. Phylogenetic analysis showed that OsLG3 might have much potential value for improvement of grain length in japonica breeding.

CONCLUSIONS

The results demonstrated that Ho-LAMap is a potential approach for gene discovery and OsLG3 is a promising gene to be utilized in genomic assisted breeding for rice cultivar improvement.

HBV/HCV co-infection is associated with a high level of HCV spontaneous clearance among drug users and blood donors in China

Understanding the biology of spontaneous clearance of hepatitis C virus (HCV) infection could lead to improved strategies to prevent the sequelae associated with chronic HCV infection. Chronic infections with hepatitis virus are very common in China, but the factors associated with spontaneous clearance of HCV have not been adequately studied. We evaluated the spontaneous clearance of HCV among 1918 drug users and 1526 HCV-seropositive blood donors in Guangzhou, China. Among participants who were co-infected with hepatitis B virus (HBV), 41.38% of drug users and 39.47% of blood donors had cleared their HCV infection without antiviral therapy compared to 9.41% of drug users and 16.73% of blood donors who were mono-infected with a single virus (P<.01). The proportion of subjects who had cleared their HCV infection was significantly greater in the co-infected subjects whose serum HBV DNA was greater than 2000IU/mL than those with lower levels. A multiple logistic regression analysis found female gender, IL28B rs8099917 TT genotype, HBV co-infection and blood donors (vs drug users) associated with increased spontaneous clearance of HCV infection. Although acute HCV infections are common in China, the incidence of chronic HCV may be reduced among the high prevalence of chronic HBV and IL28B genotypes associated with spontaneous clearance of HCV in Chinese populations.

[Peripheral nerve injury in LAMA2-related congenital muscular dystrophy patients]

Objective: To explore the injury pattern and features of peripheral nerve in congenital muscular dystrophy patients caused by LAMA2 gene mutation. Method: Seventeen patients genetically or molecular pathologically diagnosed as LAMA2-related congenital muscular dystrophy were recruited in Peking University First Hospital between 2002 and 2015. All the patients received nerve conduction velocity (NCV) and needle electromyography tests. Clinical and laboratory examination data of the patients was retrospectively analyzed. The correlation between the NCV and disease course was determined by Pearson correlation analysis. Additionally, one patient underwent a sural nerve biopsy. Result: Among these 17 identified patients (13 male and 4 female), all of them were diagnosed as congenital muscular dystrophy, and all of them underwent electrophysiological examination at ages between 1 month to 6 years. Electromyogram indicated seventeen patients of myogenic damage, of whom 10 cases were complicated with reduced NCV. Twenty-six of 95 analyzed nerves showed NCV slower than the normal average of contemporary in 17%-47%. Correlation analysis between NCV and the disease course indicated that NCV of median nerves, ulnar nerves, tibial nerves and common peroneal nerves were negatively associated with the disease course (r=-0.737, -0.771, -0.540 and -0.682, respectively; all P<0.05). Sural nerve biopsy revealed peripheral neuropathy changes of myelin. Conclusion: There is peripheral nerve injury in LAMA2-related muscular dystrophy patients. It mainly manifests as demyelinating lesions. Moreover, the NCV of peripheral nerve will decrease with the increase of the course of the disease.

OsASR5 enhances drought tolerance through a stomatal closure pathway associated with ABA and H2 O2 signalling in rice

Drought is one of the major abiotic stresses that directly implicate plant growth and crop productivity. Although many genes in response to drought stress have been identified, genetic improvement to drought resistance especially in food crops is showing relatively slow progress worldwide. Here, we reported the isolation of abscisic acid, stress and ripening (ASR) genes from upland rice variety, IRAT109 (Oryza sativa L. ssp. japonica), and demonstrated that overexpression of OsASR5 enhanced osmotic tolerance in Escherichia coli and drought tolerance in Arabidopsis and rice by regulating leaf water status under drought stress conditions. Moreover, overexpression of OsASR5 in rice increased endogenous ABA level and showed hypersensitive to exogenous ABA treatment at both germination and postgermination stages. The production of H₂ O₂ , a second messenger for the induction of stomatal closure in response to ABA, was activated in overexpression plants under drought stress conditions, consequently, increased stomatal closure and decreased stomatal conductance. In contrast, the loss-of-function mutant, osasr5, showed sensitivity to drought stress with lower relative water content under drought stress conditions. Further studies demonstrated that OsASR5 functioned as chaperone-like protein and interacted with stress-related HSP40 and 2OG-Fe (II) oxygenase domain containing proteins in yeast and plants. Taken together, we suggest that OsASR5 plays multiple roles in response to drought stress by regulating ABA biosynthesis, promoting stomatal closure, as well as acting as chaperone-like protein that possibly prevents drought stress-related proteins from inactivation.

Effects of feeding frequency on meat quality traits and Longissimus muscle proteome in finishing pigs

Sixty-four barrows with an initial body weight of 59.8 ± 2.1 kg were allocated to one of the two feeding frequency regimes (had free access to diet and fed two meals per day). Pigs had free access (FA) to feed were fed on an ad libitum basis during the 8-week experimental period. Pigs fed twice daily (M2) were allowed to consume their meals in 2 h. Pigs fed twice daily had lower average daily feed intake (p < 0.01) and average daily gain (p < 0.1), but a greater G:F (p < 0.05) than FA pigs. Lower perirenal fat deposition, hot carcass weight, intramuscular fat content (p < 0.05) and dressing percentage (p < 0.1) were found in M2 pigs compared with FA pigs. Activities of citrate synthase, β-hydroxylacyl-CoA dehydrogenase and lactate dehydrogenase were greater in the Longissimus muscle (LM) of M2 pigs compared with FA pigs (p < 0.05). Proteomic analysis revealed that expression abundances of proteins involved in glucose metabolism, energy production and lipid utilization were upregulated, but expression levels of proteins participating in protein and amino acid metabolism, stress response and redox homeostasis were downregulated in the LM of M2 pigs than those in FA pigs (p < 0.05). In conclusion, the less meal frequency impairs growth rate, has marginal effects on carcass and meat quality traits and affects expression abundances of proteins in the LM of finishing pigs.

Biological Characteristics of H9N2 Avian Influenza Viruses from Healthy Chickens in Shanghai, China

Background

H9N2 avian influenza viruses that circulate in domestic poultry in eastern China pose challenges to human health. However, few studies have compared the biological characteristics of H9N2 viruses isolated from healthy chickens in Shanghai.

Material/Methods

Three H9N2 viruses – CK/SH/Y1/07, CK/SH/Y1/02, and CK/SH/23/13 – isolated from healthy chickens in Shanghai between 2002 and 2013, were selected and their biological characteristics were determined.

Results

All 3 H9N2 viruses showed a preference for both the avian- and human-like receptors, and they replicated well in MDCK and A549 cells. All H9N2 viruses were non-pathogenic to mini-pigs and were detected in the trachea and lung tissues. The CK/SH/Y1/07 and CK/SH/Y1/02 viruses were transmitted to mini-pigs through direct-contact or respiratory droplet exposure, but CK/SH/23/13 virus was not.

Conclusions

These results suggest that H9N2 viruses isolated from healthy chickens in Shanghai efficiently replicate and transmit among pigs and other mammals.

The microRNA-182-PDK4 axis regulates lung tumorigenesis by modulating pyruvate dehydrogenase and lipogenesis

Reprogrammed metabolism is one of the hallmarks of cancer. The dysregulation of glycolysis in cancer has been heavily studied. However, it remains largely unclear how other metabolic processes are regulated in cancer cells. Here we show that microRNA-182 (miR-182) suppresses pyruvate dehydrogenase (PDH) kinase 4 (PDK4) and promotes lung tumorigenesis. miR-182 is dysregulated and inversely correlated with PDK4 in human lung adenocarcinomas. The miR-182-PDK4 axis regulates lung cancer cell growth by modulating the activity of PDH, the gatekeeping enzyme of pyruvate flux into acetyl-CoA, and subsequently de novo lipogenesis of cancer cells. Suppression of lipogenesis by silencing ATP citrate lyase (ACLY) and fatty acid synthase (FASN) or by chemical inhibitors diminishes the effects of miR-182-PDK4 in tumor growth. Alteration of de novo lipogenesis also affects reactive oxygen species (ROS) production and the downstream JNK signaling pathway. Hence, our work suggests that the miR-182-PDK4 axis is a crucial regulator of cancer cell metabolism and a potential target for antitumor therapy.

[A clinical analysis for sudden sensorineural hearing loss withcontralateral sensorineural hearing loss]

Objective:To analyze the clinical characteristics and prognosis,and to learn the impact factors of patients with sudden sensorineural hearing loss with contralateral sensorineural hearing loss(SSHLwCSHL).Method:Clinical data of 63 cases of patients with SSHLwCSHL were analyzed systematically,including all the clinical manifestations,audiologic characteristics and the effect assessment,and compared with that of unilateral sudden sensorineural hearing loss(USSHL) and bilateral sudden sensorineural hearing loss(BSSHL).Base on those,we summarized comprehensively the development and prognosis characteristics of the disease.Result:The incidence of SSHLwCSHL was 8.3 percent of overall patients with SSNHL.SSHLwCSHL occurs more commonly in male patients,with more vertigo,diabetes mellitus,and lipid panel abnormalities compared with other groups.Hearing curve and the degree of hearing loss of the prevalence ear of SSHLwCSHL was statistically significant difference with USSHL(P<0.05).Most common reason of the contralateral hearing loss was sudden sensorineural hearing loss(49%),and 59% patients of SSHLwCSHL suffered hearing loss of other ear after 2-10 years after contralateral hearing loss.The total effective rate was 14.3%,1 in 63 patients cured,1 excellence and 6 effective.The total effective rate was 9.5% in patients with severe or profound sensorineural hearing loss in the contralateral ear,which was lower than that of patients with moderate and moderately severe sensorineural hearing loss in the contralateral-ear(P=0.021).Conclusion:SSHLwCSHL has complex condition.The prognosis for improvement is poor.Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.

Association of Carney Complex with an Intronic Splice Site Mutation in the PRKAR1A Gene

This study was aimed to investigate the clinical features and mutations in the PRKAR1A gene of a multigenerational kindred including 17 individuals at risk for Carney complex. Eight patients were diagnosed with Carney complex among the 17 individuals (47.1%). Among the 8 affected patients, 4 had cardiac myxomas, 8 had skin pigmentation, and 3 had diabetes. Genomic DNA sequencing in 14 surviving patients showed 6 had the same germline mutation in the sixth intron and affected the splice site. cDNA sequencing and DNAMAN software showed 159 bases were absent, resulting in the absence of the amino acids 249 to 301 from the protein. All 6 patients with this PRKAR1A gene mutation had skin pigmentation. In conclusion, the present study reported for the first time an intronic splice site mutation in the PRKAR1A gene of a Chinese family with Carney complex, which probably caused skin pigmentation observed in affected family members.

Association between the interleukin-6-174 G/C polymorphism and risk of ischemic stroke: a meta-analysis

Numerous studies have evaluated the association between the -174 G/C polymorphism in the interleukin-6 (IL6) gene and ischemic stroke risk. However, the results have been inconsistent. In this study, we performed a meta-analysis to assess the association of the IL6 -174 G/C polymorphism with ischemic stroke. Published literatures from PubMed and Embase databases were retrieved. Pooled ORs with 95%CIs were calculated using fixed- or random-effect models. A total of seven case-control studies containing 2025 patients and 2174 controls were enrolled into this meta-analysis. In combined analysis, the results showed no significant association between the IL6 -174 G/C polymorphism and ischemic stroke risk in the overall population (GG vs CC: OR = 1.22, 95%CI = 0.50-3.01; TT vs TC: OR = 0.97, 95%CI = 0.81-1.15; dominant: OR = 0.98, 95%CI = 0.70-1.38; or recessive: OR = 1.24, 95%CI = 0.57-2.70) models. In the subgroup analysis by race, no significant associations between the -174 G/C polymorphism in the IL6 gene and ischemic stroke risk were found in Caucasians or Asians. No publication bias was found in the present study (all P > 0.05). Overall, the meta-analysis results suggested that the IL6 -174 G/C polymorphism was not associated with an increased risk of ischemic stroke. Further large and well-designed studies are needed to confirm this conclusion.

Electrospun PLA/MWCNTs composite nanofibers for combined chemo- and photothermal therapy

Carbon nanotubes are effective thermal generators by absorbing near-infrared radiation (NIR). In this study, multiwalled carbon nanotubes (MWCNTs) and doxorubicin (DOX) were successfully electrospun into the poly-l-lactic acid (PLLA) nanofibers. It is confirmed that NIR radiation could not only initiate burst release of DOX from the fibers due to the relatively low glass transition temperature (Tg) of PLLA, but also significantly increase the temperature of fibers-covering tumor site. The multifunctional fibers showed increased cytotoxicity both in vitro and in vivo by the combination of photothermal induced hyperthermia and chemotherapy with DOX. This drug delivery system could be very useful and convenient in future clinical applications for localized cancer therapy.

STATEMENT OF SIGNIFICANCE

Combination of chemo- and photothermal therapy has been widely researched owing to its enhanced cancer treatment efficacy. In this study, chemotherapy and photothermal therapy were integrated into one single system using electrospun DOX/MWCNTs loaded PLLA nanofiber mats and the anti-cancer efficacy of the fibers was studied in vivo for the first time. The effective NIR irradiation control showed a typical switch on/off effect on the release behavior of drug. As local delivery system, the fibers maximize the drug concentration in tumor and keep the MWCNTs in the surroundings of tumor, thus allowing a repeated localized heating. The high porosity of nanofibers is easy for cell binding, which may present an attractive alternative for local hyperthermia treatment of easily metastasizing tumors.

Immunomodulatory effects of hyperthermia on resisting WSSV infection in Procambarus clarkii

White spot disease remains a constant threat to aquaculture worldwide. Hyperthermia has been shown to reduce mortality in white spot syndrome virus (WSSV)-infected shrimps, but the mechanism still remains unclear. In this study, we sought to identify host immune factors that contribute to inhibition of WSSV infection during hyperthermia. In WSSV-infected red swamp crayfish Procambarus clarkii (Girard) cultured at 24 ± 1 °C, transcriptional levels of the heat shock protein 70 (Hsp70) gene showed a modest, 2.2-fold increase in haemocytes following 48 h post-infection (hpi). In contrast, in WSSV-infected crayfish cultured at 32 ± 1 °C, Hsp70 gene expression showed a rapid, 19.5-fold induction by 4 hpi. This suggests that Hsp70 plays a positive regulatory role in resistance to WSSV infection during hyperthermia. Furthermore, total haemocyte counts (THC) and phenoloxidase (PO) activity were both significantly increased in WSSV-infected crayfish cultured at 32 ± 1 °C by 48 hpi. Both may be critical for crayfish survival in the late stages of WSSV infection. Collectively, the up-regulation of host protein Hsp70 expression and increase in THC and PO activity suggest that hyperthermia has immunomodulatory effect that enhanced the resistance of P. clarkii to WSSV infection.

The relationship between heart-carotid pulse transit time and carotid intima-media thickness in hypertensive patients

The study aimed to investigate the relationship between heart-carotid pulse transit time and carotid intima-media thickness (CIMT) in hypertensive patients, and whether including the pre-ejection period (PEP) in heart-carotid pulse transit time would affect this correlation. A total of 62 hypertensive patients were included in this study. They were divided into the normal CIMT group (n=33, CIMT⩽0.8 mm) and the thickened CIMT group (n=29, CIMT>0.8 mm). The noninvasive ultrasound method was used to measure CIMT, electrocardiogram R-wave-based heart-carotid pulse transit time (rcPTT) and PEP. Aortic valve-carotid artery pulse transit time (acPTT) was calculated by subtracting PEP from rcPTT. Simple linear analysis showed that CIMT was negatively associated with rcPTT and acPTT (r=-0.57, P<0.0001; r=-0.41, P=0.016) in the normal CIMT group as well as in the thickened CIMT group (r=-0.50, P=0.0053; r=-0.59, P=0.001). These relationships were eliminated in the normal CIMT group after adjusting for age, gender, smoking behaviour, systolic blood pressure, diastolic blood pressure and cholesterol levels. However, rcPTT and acPTT still showed significant correlations with CIMT in the thickened CIMT group. In conclusion, rcPTT and acPTT were associated with CIMT, independent of well-known clinical confounders in thickened CIMT hypertensive patients. Therefore, rcPTT and acPTT might be useful markers for atherosclerosis evaluation.