Study on Optimal Extraction and Hypoglycemic Effect of Quercetin.

Quercetin was extracted from Portulaca oleracea L. through biphasic acid hydrolysis to investigate its potential as a suppressor of dipeptidyl peptidase IV (DPP-IV) and its hypoglycemic effect in type 2 diabetic mice. The extraction procedure was optimized utilizing the response surface method (RSM) in a single-factor experimental setting. An extraction efficiency of 0.675% was achieved using the following optimized parameters: 0.064 mol/L vitriol, 1 : 109.155 solid-liquid ratio, and 21.408 min ultrasonication. Overall, findings indicate the effectiveness of quercetin extraction. A mouse model for type 2 diabetes was established to receive oral treatment with various quercetin concentrations for 8 weeks. Fasting blood glucose (FBG) and the DPP-IV activity in the serum were significantly reduced. The weight and insulin levels of the mice in the quercetin group were raised compared to those in the model group (P < 0.01). Quercetin dose-dependently inhibited postprandial blood glucose excursions, as demonstrated by the oral glucose tolerance test. These results confirmed that quercetin has hypoglycemic effects and considerably improves insulin sensitivity via DPP-IV targeting.

The mechanism of circadian clock and its influence on animal circannual rhythm.

The circadian clock exists in almost all life forms, and is an internal activity generated by organisms adapting to the daily periodic changes of the external environment. The circadian clock is regulated by the transcription-translation-negative feedback loop in the body, which can regulate the activities of tissues and organs. Its normal maintenance is important for the health, growth, and reproduction of organisms. In contrast, due to the season changes of the environment, organisms have also formed annual cycle physiological changes in their bodies, such as seasonal estrus, etc. The annual rhythm of living things is mainly affected by environmental factors such as photoperiod, and is related to gene expression, hormone content, morphological changes of cell and tissues in vivo. Melatonin is an important signal to recognize the changes of photoperiod, and the circadian clock plays an important role in the pituitary to interpret the signal of melatonin and regulate the changes of downstream signals, which plays an important guiding role in the recognition of annual changes in the environment and the generation of the body's annual rhythm. In this review, we summarize the progress of research on the mechanism of action of circadian clocks in influencing annual rhythms, by introducing the mechanisms of circadian and annual rhythms generation in insects and mammals, and in the context of annual rhythms in birds, with the aim of providing a broader range of ideas for future research on the mechanism of annual rhythms influence.

Responses of soil pH to no-till and the factors affecting it: A global meta-analysis.

No-till (NT) is a sustainable option because of its benefits in controlling erosion, saving labor, and mitigating climate change. However, a comprehensive assessment of soil pH response to NT is still lacking. Thus, a global meta-analysis was conducted to determine the effects of NT on soil pH and to identify the influential factors and possible consequences based on the analysis of 114 publications. When comparing tillage practices, the results indicated an overall significant decrease by 1.33 ± 0.28% in soil pH under NT than that under conventional tillage (p < .05). Soil texture, NT duration, mean annual temperature (MAT), and initial soil pH are the critical factors affecting soil pH under NT. Specifically, with significant variations among subgroups, when compared to conventional tillage, the soil under NT had lower relative changes in soil pH observed on clay loam soil (-2.44%), long-term implementation (-2.11% for more than 15 years), medium MAT (-1.87% in the range of 8-16℃), neutral soil pH (-2.28% for 6.5 < initial soil pH < 7.5), mean annual precipitation (-1.95% in the range of 600-1200 mm), in topsoil layers (-2.03% for 0-20 cm), with crop rotation (-1.98%), N fertilizer input (the same for NT and conventional tillage) of 100-200 kg N ha-1 (-1.83%), or crop residue retention (-1.52%). Changes in organic matter decomposition under undisturbed soil and with crop residue retention might lead to a higher concentration of H+ and lower of basic cations (i.e., calcium, magnesium, and potassium), which decrease the soil pH, and consequently, impact nutrient dynamics (i.e., soil phosphorus) in the surface layer under NT. Furthermore, soil acidification may be aggravated by NT within site-specific conditions and improper fertilizer and crop residue management and consequently leading to adverse effects on soil nutrient availability. Thus, there is a need to identify strategies to ameliorate soil acidification under NT to minimize the adverse consequences.

Application of genetic modification technologies in molecular design breeding of sheep.

Genetic modification technologies can be used for modifying animal genome to express exogenous genes or affect the function of endogenous genes. In animal breeding, genetic modification technologies allow the rapid generation of germplasms with beneficial traits. It includes traditional genetic modification, virus or sperm carrier-mediated genetic modification and nuclease-mediated genome editing, especially the CRISPR/Cas9, one of the artificial nuclease genome editing technologies, have been applied in genome editing in many domestic animals including sheep (Ovis aries). Compared with conventional strategies used for animal breeding, there is great value for sheep breeding improvement by using genome editing technology, which is more effective and timesaving. In this review, we summarize the approaches of genetic modification in sheep and discuss the possibility of molecular design and breeding of sheep by genome editing technologies. We also identify the potential bottlenecks and challenges of these technologies in sheep breeding.

Strategic tillage achieves lower carbon footprints with higher carbon accumulation and grain yield in a wheat-maize cropping system.

Continuous single tillage has the potential to increase greenhouse gas (GHG) emissions and decrease the accumulation of soil organic carbon (SOC), thus increasing carbon footprints (CFs). However, in a wheat-maize cropping system, limited information was available about the effects of strategic tillage on CFs. Thus, a four-year field experiment was conducted, including continuous rotary tillage (RT), continuous no-till (NT), RT + subsoiling (RS), and NT + subsoiling (NS), to investigate the effects of NS (strategic tillage) on the unit area and unit yield. The results showed that CO2 emission was the highest contributor to CFs (73.92%) in a winter wheat-summer maize cropping system, following the order of NS < NT < RS < RT. The direct N2O emissions from fertilizers and residues were 4.43-4.51 t CO2-eq ha-1 yr-1 during the wheat and maize seasons, and indirect N2O emissions from irrigation and fertilizer inputs had a proportion of >80% from total agricultural inputs. The differences in SOC storage significantly affected the CFs. Although the NS treatment increased the amount of GHG emissions from the residues returned and consumption of diesel, the enhancement of SOC storage by deeper SOC increased. Thus, lower area-scaled CFs were observed in the NS treatment. Furthermore, a higher grain yield and an annual change of SOC storage compared with other treatments were observed under the NS system, which helped to reduce the CFs. The yield-scaled CFs followed the order of RT > RS > NT > NS when considering the changes in SOC storage. Therefore, the NS treatment resulted in a higher grain yield and SOC sequestration with lower CFs, and thus, it could be recommended as the best tillage method to achieve sustainable production and environmental balance in a wheat-maize cropping system.

Expression analysis and single-nucleotide polymorphisms of SYNDIG1L and UNC13C genes associated with thoracic vertebral numbers in sheep (Ovis aries).

The objective of the current study was to analyze expression levels of synapse differentiation inducing 1-like (SYNDIG1L) and unc-13 homolog C (UNC13C) genes in different tissues, while single-nucleotide polymorphisms (SNPs) of two genes were associated with multiple thoracic vertebrae traits in both Small-tailed Han sheep (STH) and Sunite sheep (SNT). The expression levels of SYNDIG1L and UNC13C were analyzed in the brain, cerebellum, heart, liver, spleen, lung, kidney, adrenal gland, uterine horn, longissimus muscle, and abdominal adipose tissues of two sheep breeds with different thoracic vertebral number (TVN) sheep (T13 groups and T14 groups) by real-time quantitative polymerase chain reaction (RT-qPCR). Meanwhile, the polymorphisms of UNC13C gene g.52919279C > T and SYNDIG1L gene g.82573325C > A in T14 and T13 were genotyped by the Sequenom MassARRAY® SNP assay, and association analysis was performed with the TVN. The results demonstrated that UNC13C gene was extensively expressed in 11 tissues. The expression of UNC13C gene in longissimus muscle of T14 groups of STH was significantly higher than that of T13 groups ( P < 0.05 ). SYNDIG1L gene was overexpressed in brain and cerebellum tissues, and the expression level of UNC13C gene in the brain and cerebellum of T13 groups in SNT was significantly higher than that of T14 groups ( P < 0.01 ). Association analysis showed that SNPs found in the UNC13C gene had no significant effects on TVN for both two genes. The polymorphism of SYNDIG1L g.82573325C > A was significantly correlated with the TVN in both STH ( P < 0.05 ) and SNT ( P < 0.01 ). Taken together, the SYNDIG1L gene was related to thoracic vertebral development, and this variation may be potentially used as a molecular marker to select the multiple thoracic vertebrae in sheep.

Expression characteristics of pineal miRNAs at ovine different reproductive stages and the identification of miRNAs targeting the AANAT gene.

BACKGROUND: Many recent studies have shown that miRNAs play important roles in the regulation of animal reproduction, including seasonal reproduction. The pineal gland is a crucial hub in the regulation of seasonal reproduction. However, little is known about the expression characteristics of pineal miRNAs in different reproductive seasons (anestrus and breeding season). Therefore, the expression profiles and regulatory roles of ovine pineal miRNAs were investigated during different reproductive stages using Solexa sequencing technology and dual luciferase reporter assays. RESULTS: A total of 427 miRNAs were identified in the sheep pineal gland. Significant differences in miRNA expression were demonstrated between anestrus and the breeding season in terms of the frequency distributions of miRNA lengths, number of expressed miRNAs, and specifically and highly expressed miRNAs in each reproductive stage. KEGG analysis of the differentially expressed (DE) miRNAs between anestrus and the breeding season indicated that they are significantly enriched in pathways related to protein synthesis, secretion and uptake. Furthermore, transcriptome analysis revealed that many target genes of DE miRNAs in the ribosome pathway showed relatively low expression in the breeding season. On the other hand, analyses combining miRNA-gene expression data with target relationship validation in vitro implied that miR-89 may participate in the negative regulation of aralkylamine N-acetyltransferase (AANAT) mRNA expression by targeting its 3'UTR at a unique binding site. CONCLUSIONS: Our results provide new insights into the expression characteristics of sheep pineal miRNAs at different reproductive stages and into the negative regulatory effects of pineal miRNAs on AANAT mRNA expression.

Polymorphism, expression and structure analysis of key genes in the ovarian steroidogenesis pathway in sheep (Ovis aries).

BACKGROUND: Litter size is an important factor that significantly affects the development of the sheep industry. Our previous TMT proteomics analysis found that three key proteins in the ovarian steroidogenesis pathway, STAR, HSD3B1, and CYP11A1, may affect the litter size trait of Small Tail Han sheep. OBJECTIVE: The purpose of this study was to better understand the relationship between polymorphisms of these three genes and litter size. MATERIAL AND METHOD: Sequenom MassARRAY detected genetic variance of the three genes in 768 sheep. Real-time qPCR of the three genes was used to compare their expression in monotocous and polytocous sheep in relevant tissues. Finally, bioinformatics analysis predicted the protein sequences of the different SNP variants. RESULT: Association analysis showed that there was a significant difference in litter size among the genotypes at two loci of the CYP11A1 gene (p < 0.05), but no significant difference was observed in litter size among all genotypes at all loci of the STAR and HSD3B1 genes (p > 0.05). However, STAR expression was significantly different in polytocous and monotocous sheep in the pituitary (p < 0.01). Tissue-specific expression in the ovary was observed for HSD3B1 (p < 0.05), but its expression was not different between polytocous and monotocous sheep. Bioinformatics analysis showed that the g.33217408C > T mutation of CYP11A1 resulted in major changes to the secondary and tertiary structures. In contrast, gene polymorphisms in STAR and HSD3B1 had minimal impacts on their protein structures. DISCUSSION: This may explain why the CYP11A1 variant impacted litter size while the others did not. The single nucleotide polymorphism of the CYP11A1 gene would serve as a good molecular marker when breeding to increase litter size in sheep. Our study provides a basis for further revealing the function of the ovarian steroidogenesis pathway in sheep reproduction and sheep breeding.

Temporal variation of SOC storage and crop yield and its relationship - A fourteen year field trial about tillage practices in a double paddy cropping system, China.

Carbon (C) sequestration in agricultural systems is recommended as a beneficial measure for climate change mitigation and food security. Despite much research, the relationship between soil organic carbon (SOC) storage and sustainable crop productivity has not been identified for various agricultural ecosystems, especially in the paddy ecosystem where conservation tillage has been adopted. Thus, a long-term experiment was conducted to evaluate the effects of tillage practices on SOC storage, yield, and their relationship in a double-cropped rice (Oryza sativa L.) paddy in Southern China from 2005 to 2018. Four tillage systems were investigated: no-till with residue retained on the soil surface (NTS), rotary tillage with residue retention (RTS), plow tillage with residue retention (CTS), and plow tillage with residue removed (CT). The SOC accumulation in the 0-20 cm layer in tillage systems included two stages: the rapid accumulation stage (2005-2007) and the slow fluctuation stage (2007-2018), with a tendency for C saturation. After reaching C saturation, the increase in SOC storage was not obvious, even with continued C input, and the SOC storage under different tillage systems was inconsistent. In general, SOC storage under NTS was the greatest. Interannual changes were not significant, while cumulative yield (2005-2018) was highest under CTS (162.13 t ha-1), followed by RTS (158.46 t ha-1), NTS (153.99 t ha-1), and CT (149.70 t ha-1). Tillage practices had no effect on the yield stability of late rice, but a significant difference in early rice was noticed between CTS and RTS. A non-linear relationship between rice yield and SOC storage was significant (P < 0.0001). With increasing SOC, yields tended to increase first and then decrease. Thus, innovative tillage strategies (such as NTS) could increase SOC storage before it reaches C saturation, but maintaining SOC storage within a reasonable range and optimizing SOC distribution might be more beneficial for crop productivity than a higher SOC storage, especially in C-rich paddy fields.

Effects of tillage management on soil carbon decomposition and its relationship with soil chemistry properties in rice paddy fields.

Decreasing the soil organic carbon (SOC) decomposition is critical to improve the quality of the soil and mitigate atmospheric CO2 emissions. To improve the ability to protect the SOC by optimizing tillage management, this study investigated the laboratory-based SOC mineralization (decomposition) and soil chemical properties under different tillage practices, including no tillage with straw mulch (NTS), rotary tillage with straw incorporated (RTS), moldboard plow tillage with straw incorporated (CTS) and moldboard plow tillage with straw removal (CT). Soil samples of six sampling dates from April 2017 to October 2018 were incubated at 25 °C and 70% water holding capacity for 60 d. Repeated Variance Analyses were conducted to compare the means of different treatments. The results showed that the average cumulative SOC mineralization (Cm) at the 0-5 cm soil depth was 7.09 g CO2 kg-1 soil under NTS, which was higher (P < 0.05) than that of the other treatments. However, the C mineralizability at both the 0-5 and 5-10 cm soil depths were lower (P < 0.05) under the NTS (0.16 and 0.15 g CO2 g-1 SOC) compared with the CTS and CT. Non-microbial CO2 emissions (CO2 emissions in sterilized soil) contributed to the lower C mineralizability under NTS, due to the lower mineralizability (0.041-0.089 g CO2 g-1 SOC) of sterilized soil under this treatment. Furthermore, some of the abiotic factors (e.g., C/N ratio and SOC content) significantly correlated with the Cm and C mineralizability. These factors might be critical for the ability to protect SOC under NTS. In summary, conservation tillage is an optimal management due to its protection on SOC, and part of this protection appeared to have been contributed by the soil abiotic factors, which were formed by long-term tillage management.

[Locally delivered macrolides as an adjunct to non-surgical periodontal treatment of chronic periodontitis: a meta analysis].

PURPOSE: The present meta analysis was designed to determine the effects of macrolides group of antibiotics as local drug delivery agents to scaling and root planing (SRP), compared with SRP alone or plus placebo. METHODS: Electronic and manual literature searches were conducted to select randomized controlled trials (RCTs) comparing SRP + macrolides versus SRP alone using the following databases: PubMed, Cochrane Library, Science Direct, EMbase, CNKI, Wanfang database and VIP data until August 2018. Two reviewers independently extracted the data and evaluated the methodological quality of the included studies. RevMan 5.3 was applied for meta analysis. RESULTS: Seven papers were obtained, which included 439 patients with chronic periodontitis.Meta analysis showed that in the two groups, the changes in probing depth（PD）[MD=0.77, 95%CI(0.48-1.05), P<0.00001], clinical attachment loss（CAL）[MD=0.74, 95%CI(0.39-1.10), P<0.0001],plaque index（PI）[MD=0.30, 95% CI(0.17-0.43), P<0.00001]，modified sulcus bleeding index (mSBI)[MD=0.23, 95%CI(0.15-0.32), P<0.00001]at 3 month and 6 month of PD[MD=1.15, 95%CI(0.41-1.89), P=0.002] were significantly different, the difference of CAL[MD=0.92, 95%CI(0.43-1.40), P=0.0002], PI[MD=0.51, 95%CI(0.07-0.95), P=0.02] and mSBI[MD=0.18, 95%CI(0.07-0.29), P=0.002] was also significant (P<0.05). CONCLUSIONS: SRP combined with local macrolides adjuvant treatment for chronic periodontitis is effective in short-term observation.

[Comparison of different single cell whole genome amplification methods and MALBAC applications in assisted reproduction].

Single-cell whole genome amplification (WGA) is a new technology, which can amplify small amounts of DNA from single cell and obtain the high coverage whole genome DNA template for revealing cell heterogeneity. Single cell WGA methods mainly include primer extension preamplification PCR (PEP-PCR), degenerate oligonucleotide primed PCR (DOP-PCR), multiple displacement amplification (MDA), and multiple annealing and looping-based amplification cycles (MALBAC). In this review, we describe the principles and applications of different single cell genome wide amplification, and we evaluate and compare their amplification efficiency, including the coverage of genome, homogeneity, reproducibility, and detection power of single-nucleotide variants (SNV) and copy number variants (CNV). The results show that MALBAC have the highest amplification homogeneity, the lowest allelic gene knockdown rate, the best reproducibility, and the best detection effect on CNV and SNV. We also describe the applications of MALBAC in human single sperm meiosis, aneuploidy analysis, and human oocyte genome research.

[The molecular mechanism of sheep seasonal breeding and artificial regulatory techniques for estrus and mating in anestrus].

Seasonal breeding is an important factor limiting sheep production efficiency. Detailed analysis on the molecular mechanisms of seasonal breeding is the premise for improving estrus and mating rate of sheep during anestrus. Recent research showed that under long-photoperiod and short-photoperiod conditions, a series of changes in signaling molecules and cell morphology could be observed in ovine seasonal reproduction pathway. Based on the molecular mechanisms of seasonal reproduction, several technologies or methods for inducing estrus and mating of ewes in anestrus have been developed. In this review, photoperiod-induced changes in signaling molecules and cell morphology in pituitary and hypothalamic tissue are first summarized in terms of the molecular mechanisms and characteristics of seasonal reproduction. The application effect, advantages and disadvantages for applying these technologies for inducing estrus and mating of ewes in anestrus are then discussed, thereby providing the critical insights in identifying a new technology, which is environmentally friendly and efficient, to improve breeding rate in anestrus.

Inflammation responses in patients with pulmonary tuberculosis in an intensive care unit.

Pulmonary tuberculosis caused by Mycobacterium tuberculosis remains a global problem. Inflammatory responses are the primary characteristics of patients with pulmonary tuberculosis in intensive care units (ICU). The aim of the present study was to investigate the clinical importance of inflammatory cells and factors for patients with pulmonary tuberculosis in ICU. A total of 124 patients with pulmonary tuberculosis in ICU were recruited for the present study. The inflammatory responses in patients with pulmonary tuberculosis in ICU were examined by changes in inflammatory cells and factors in the serum. The results indicated that serum levels of lymphocytes, plasma cells, granulocytes and monocytes were increased in patients with pulmonary tuberculosis in ICU compared with healthy controls. The serum levels of inflammatory factors interleukin (IL)-1, IL-6, IL-10, IL-12, and IL-4 were upregulated in patients with pulmonary tuberculosis in ICU. Lower plasma concentrations of IL-2, IL-15 and interferon-γ were detected in patients with pulmonary tuberculosis compared with healthy controls. It was demonstrated that high mobility group box-1 protein expression levels were higher in the serum of patients with pulmonary tuberculosis compared with healthy controls. Notably, an imbalance of T-helper cell (Th)1/Th2 cytokines was observed in patients with pulmonary tuberculosis. Pulmonary tuberculosis caused by M. tuberculosis also upregulated expression of matrix metalloproteinase (MMP)-1 and MMP-9 in hPMCs. In conclusion, these outcomes demonstrated that inflammatory responses and inflammatory factors are associated with the progression of pulmonary tuberculosis, suggesting that inhibition of inflammatory responses and inflammatory factors may be beneficial for the treatment of patients with pulmonary tuberculosis in ICU.

Anaerobic decolorization and detoxification of cationic red X-GRL by Shewanella oneidensis MR-1.

The ability of an electrochemically active bacterium, Shewanella oneidensis MR-1, to decolorize azo dye cationic red X-GRL (X-GRL) was investigated. S. oneidensis MR-1 showed a high decolorization capability for X-GRL under anaerobic conditions. The Mtr respiratory pathway was proved to be involved in the extracellular decolorization of X-GRL. The decolorization efficiency of S. oneidensis MR-1 was significantly inhibited when the initial X-GRL concentration was over 200 mg L-1. Increasing the inoculum volume of S. oneidensis MR-1 could obviously promote the X-GRL decolorization. The 100 mg L-1 X-GRL and 6% (v/v) inoculum volume were chosen as the optimal parameter. Under such a condition, almost all of X-GRL (100 mg L-1) could be completely reduced after 12-h incubation at the pH range of 5.5-8.0 and temperature range of 30-40°C. Salinity in the medium also affected X-GRL decolorization. Lactate and citric acid were found to be the suitable electron donors for X-GRL decolorization. Although the genotoxicity increased slightly, the phytotoxicity of X-GRL in the decolorization process was significantly reduced by S. oneidensis MR-1.

A high-throughput dye-reducing photometric assay for evaluating microbial exoelectrogenic ability.

Exoelectrogenic bacteria (EEB) can transfer electrons to extracellular electron acceptors and have wide applications in environmental bioremediation and bioenergy generation. Thus, methods for effectively probing the exoelectrogenic ability of EEB are highly desirable. In this work, a simple but efficient photometric assay based on the extracellular reduction of high polar dyes was developed to evaluate the microbial exoelectrogenic ability. Methyl orange were proven to be used as a probe for evaluating the exoelectrogenic ability of EEB. Through monitoring the extracellular dye decolorization under anaerobic conditions, this plate-based photometric assay could rapidly measure the exoelectrogenic ability of various EEB. This approach was also able to evaluate the exoelectrogenic capacity of Shewanella oneidensis MR-1 wild-type strain and its Mtr mutants. Furthermore, the exoelectrogenic ability of mixed cultures in microbial fuel cells was correlated with the extracellular dye decolorization. Thus, this work is useful for the practical implementation of microbial exoelectrogenic ability evaluation.

Two single nucleotide polymorphisms sites in α1-AT gene and their association with somatic cell score in Chinese Holstein cows.

BACKGROUND: Alpha 1-antitrypsin (α1-AT) may affect the susceptibility of mastitis in dairy cattle for its possible role in the protection of lactoferrin from proteolytic degradation in the mammary. Milk somatic cell score (SCS) is a logarithmic transformation of the milk somatic cell count widely used as an index to evaluate mastitis. To study the relationships of α1-AT gene and SCS in Chinese Holstein cows, methods of PCR-SSCP, DNA sequencing, PCR-RFLP, and CRS-PCR technologies were used to detect single nucleotide polymorphisms sites in α1-AT gene. RESULTS: Two polymorphic sites at G5503A and G5746C of α1-AT gene were found. AA (0.3633), AB (0.4644) and BB (0.1723) genotypes were detected at G5503A site, CC (0.3483), CD (0.4906) and DD (0.1611) genotypes were found at G5746C in Chinese Holstein cows. Least squares mean of SCS for individuals with BB genotype was significantly lower than that with AA and AB genotype (p < 0.01), and that with AB genotype was significantly lower than that with AA (p < 0.05). There was no significant difference among individuals with CC, CD and DD genotypes (p > 0.05). Least squares mean of SCS for individuals with BBDD genotype combination were significantly lower than those with AACC and AACD (p < 0.05). CONCLUSIONS: Statistical analysis indicated that B allele and BBDD genotype combination of α1-AT can improve mastitis resistance in dairy cattle.

Selection signature in domesticated animals.

Domesticated animals play an important role in the life of humanity. All these domesticated animals undergo same process, first domesticated from wild animals, then after long time natural and artificial selection, formed various breeds that adapted to the local environment and human needs. In this process, domestication, natural and artificial selection will leave the selection signal in the genome. The research on these selection signals can find functional genes directly, is one of the most important strategies in screening functional genes. The current studies of selection signal have been performed in pigs, chickens, cattle, sheep, goats, dogs and other domestic animals, and found a great deal of functional genes. This paper provided an overview of the types and the detected methods of selection signal, and outlined researches of selection signal in domestic animals, and discussed the key issues in selection signal analysis and its prospects.

Impairment of Biofilm Formation by TiO2 Photocatalysis through Quorum Quenching.

The release of nanomaterials into the environment, due to their massive production and application today, has caused ecological and health safety concerns. Semiconductor photocatalysts like TiO2 exhibit cytotoxicity to bacterial cells when exposed to UV irradiation. However, information about their impacts on individual or group bacterial behaviors is limited. In this work, the biofilm formation of Escherichia coli K12 in the presence of TiO2 with and without UV irradiation was investigated and biofilm formation was found not to be affected under the sole application of TiO2 or UV irradiation. However, biofilm development was substantially delayed by TiO2 under UV irradiation, although no obvious cytotoxicity to cell growth was observed. The reactive oxygen species photogenerated by TiO2 were found to quench the autoinducer 2 (AI-2) signals secreted by E. coli K12. As a result, the initiation of quorum sensing for biofilm formation activated by AI-2 was restrained. The expressions of two biofilm-formation-related genes, motA and rcsB, were also suppressed. A dose of an AI-2 precursor, 4,5-dihydroxy-2,3-pentanedione, effectively restored the biofilm development. These results show that the photoexcited TiO2 could suppress biofilm formation through quenching AI-2 signals. This work may facilitate a better understanding about the ecological effects of increasingly released nanomaterials and provide implications for development of antifouling membranes.

Identification and verification of differentially expressed genes in the caprine hypothalamic-pituitary-gonadal axis that are associated with litter size.

Litter size is a favorable economic trait for the goat industry, but remains a complex trait controlled by multiple genes in multiple organs. Several genes have been identified that may affect embryo survival, follicular development, and the health of fetuses during pregnancy. Jining Grey goats demonstrate the largest litter size among goat breeds indigenous to China. In order to better understand the genetic basis of this trait, six suppression subtractive hybridization (SSH) cDNA libraries were constructed using pooled mRNAs from hypothalamuses, pituitaries, and ovaries of sexually mature and adult polytocous Jining Grey goats, as testers, versus the pooled corresponding mRNAs of monotocous Liaoning Cashmere goats, as drivers. A total of 1,458 true-positive clones--including 955 known genes and 481 known and 22 unknown expressed sequence tags--were obtained from the SSH libraries by sequencing and alignment. The known genes were categorized into cellular processes and signaling information storage and processing, and metabolism. Three genes (FTH1, GH, and SAA) were selected to validate the SSH results by quantitative real-time PCR; all three were up-regulated in the corresponding tissues in the tester group indicating that these are candidate genes associated with the large litter size of Jining Grey goats. Several other identified genes may affect embryo survival, follicular development, and health during pregnancy. This study provides insights into the mechanistic basis by which the caprine hypothalamic-pituitary-gonadal axis affects reproductive traits and provides a theoretical basis for goat production and breeding.