Biology subjects

No,

Publications and source records attributed to No,.

7 recordsLinked to original sources

bioRxiv2018

High-sensitivity c-reactive protein and total and saturated fat intake in adolescent students: a longitudinal study

ObjectiveThe present study aimed to assess the relationship between hs-CRP concentrations and total and saturated fat intake in adolescents after a year of follow-up.\n\nMethodsA longitudinal study carried out in the years 2014 and 2015 evaluated 408 adolescents from the municipal and state public schools of Joao Pessoa, Paraiba, between 10 and 14 years of age, who participated in the Longitudinal Study on Sedentary Behavior, Physical Activity, Eating Habits and Adolescent Health (LONCAAFS). Data were obtained on sociodemographic data, anthropometric nutritional status, physical activity and hs-CRP concentration. The consumption of total and saturated fats was evaluated from the 24 hour recall.\n\nResultsThe associations between concentrations of hs-CRP and total and saturated fat intake were performed by linear regression considering panel data, individual fixed effect, balanced bank, stratified by sex and BMI. The mean values of the hs-CRP variable were significantly different between the analyzed years (p = 0.024). The percentage of total and saturated fat consumption is within the recommended level in both years, with no significant difference (p> 0.05). No statistically significant associations were found between hs-CRP and total fat consumption ({beta} = -0.19p = 0.582) and saturated fat ({beta} = 0.20, p = 0.282).\n\nConclusionThe study did not present significant evidence on the relationship between the concentrations of hs-CRP and the consumption of total and saturated fats, as one year of follow-up may not have promoted evident changes in the levels of hs-CRP in adolescents.

epidemiology↗

bioRxiv2018

The Mechanical of Organic Acids Secreted by Roots of Tartary Buckwheat under the Effects of Low Nitrogen Stress

A pot experiment was conducted to study the effects of two different low nitrogen tolerant tartary buckwheat varieties (Diqing buckwheat (DQ, low nitrogen resistance) and Heifeng 1 (HF, low nitrogen sensitive) response mechanism of organic acids to low nitrogen stress. The results showed that the soil moisture of HF and DQ under low nitrogen treatment decreased 24.2% and 14.32%, respectively when compared with normal nitrogen treatment, and the water consumption of DQ was significantly higher than that of HF at seedling stage. Under low nitrogen treatment, the soil pH value of DQ was 1.44% and 8.44% lower than that of HF at seedling and flowering stages, respectively, the content of NH4+ in DQ soil was 8.2% lower than that of HF at maturity stage, the content of NO3- was significantly higher than that HF 49.2%, 12.9%, and 16.6% in each growth period, respectively. Split plot analysis showed that nitrogen treatment significantly affected the organic acids content in the soil of the buckwheat. The secretion content of organic acids are different among buckwheat cultivars under low nitrogen stress. In the soil of DQ, the content of malonic acid was higher than that of HF by 34.39% at maturity stage; the content of oxalic acid was respectively higher than that of HF by 24.86% and 24.52% at seedling and flowering stages; the content of propionic acid was significantly higher than that of HF by 7.36%, 9.44% and23.47% in each growth period, respectively; and tartaric acid acetic acid also showed the same trend at flowering and maturity stages. In summary, tartary buckwheat may regulate the nutrient availability of rhizosphere soil through the secretion of organic acids in the root system to cope with the low nitrogen stress environment. For the cultivation of tartary buckwheat on poor soil should consider the differences cultivaring barren resistance varieties to increase efficiency in the future.

plant biology↗

bioRxiv2018

Obesity impairs resistance to Leishmania major infection in C57BL/6 mice.

An association between increased susceptibility to infectious diseases and obesity has been described as a result of impaired immunity in obese individuals. It is not clear whether a similar linkage can be drawn between obesity and parasitic diseases. To evaluate the effect of obesity in the immune response to cutaneous L. major infection, we studied the ability of C57BL/6 mice submitted to a high fat and sugar diet to control leishmaniasis. Mice with diet-induced obesity presented thicker lesions with higher parasite burden and more inflammatory infiltrate in the infected ear when infected with L. major. We observe no difference in IFN-{gamma} or IL-4 production by draining lymph node cells between control and obese mice, but obese mice presented higher production of IgG1 and IL-17. A higher percentage of in vitro-infected peritoneal macrophages was found when these cells were obtained from obese mice when compared to lean mice. In vitro stimulation of macrophages with IL-17 decreased the capacity of cells from control mice to kill the parasite. Moreover, macrophages from obese mice presented higher arginase activity. Together our results indicate that diet-induced obesity impairs resistance to L. major in C57BL/6 mice without affecting the development of Th1 response.\n\nAuthor SummaryThe obesity is a public health problem and it is reaching extraordinary numbers in the world and others diseases are being involved and aggravated as consequence of obesity. What we know is that some diseases are more severe in obese people than in normal people. We did not know how obesity changes the profile of immune response to infectious agents, leading to the more severe diseases. That s why we decided to investigate how obese mice lead with Leishmania major infection. Leishmaniasis is a protozoa parasite infection considered a neglected disease. To try our hypothesis we gave a hipercaloric diet to induce obesity in C57BL/6 mice. After that, we injected L. major in the mice ear and followed the lesion for 8 weeks. We observed a ticker lesion and the cells from draining lymph node from obese mice produced more IL-17 than cells from normal mice. We also infected in vitro, macrophages from obese mice and stimulated the cells with IL-17, and we observed that the macrophages from obese mice are more infected by the L. major and it is worst in the presence of IL-17. Our results suggest that diet induced obesity decrease the resistance to infection.

immunology↗

bioRxiv2018

Effects of sublethal concentrations and application concentration of SYP-9625 on Tetranychus cinnabarinus (Boisduval) and its natural enemy, Neoseiulus californicus (McGregor)

ObjectiveExploring the effects of acaricides on predatory mites is crucial for the combination of biological and chemical control of pests. In this study, sublethal effects of the new acaricide SYP-9625 on Tetranychus cinnabarinus (Boisduval), effects of application concentration of SYP-9625 on the predatory mite Neoseiulus californicus (McGregor) and functional responses of N. californicus were assessed. The aim of the present study was to evaluate and explore the application of new acaricide SYP-9625 with natural enemy N. californicus.\n\nMethodAll the experiments were under laboratory conditions [25 {+/-} 1 {degrees}C, 16:8 (L:D) h and 75 {+/-} 5% RH] and based on an age-stage, two-sex life table. The sublethal concentrations against T. cinnabarinus, including LC10 (0.375 g/mL) and LC30 (0.841 g/mL) and the application concentration (100 g/mL) of SYP-9625, were used to evaluate effects on population parameters of N. californicus.\n\nResultT. cinnabarinus females treated with LC30 exhibited significantly reduced net reproductive rates (R0=11.02) of offspring compared to females treated with LC10 (R0=14.96) and untreated females (>R0=32.74). However, the intrinsic rate of increase (rm) and finite rate of increase ({lambda}) of N. californicus indicated that the application concentration of SYP-9625 had no significant negative effect on treated N. californicus eggs (rm=0.277,{lambda} =1.319) compared to the control (rm=0.292,{lambda} =1.338). Additionally, the sublethal concentrations against T. cinnabarinus including LC10 and LC30 showed a dose-dependent mechanism on the predatory mite. SYP-9625 also stimulated the predatory capacity of N. californicus against immobile stages such as eggs and larvae.\n\nConclusionIt is demonstrated that sublethal concentrations of SYP-9625 can inhibit population growth of T. cinnabarinus. And the sublethal concentrations and application concentration had little effect on the population growth of N. californicus. The two advantages showed great commercial potential of this new acaricide. Therefore, N. californicus can manage T. cinnabarinus populations effectively with appropriate SYP-9625 concentrations.

zoology↗

bioRxiv2018

Genetic Diversity in Common Carp Stocks from a Natural Reservoir Assayed by Randomly Amplified Polymorphic DNA Markers

BackgroundThe common carp (Cyprinus carpio) is a freshwater fish that is cultured throughout the world. C. carpio belongs to the family Cyprinidae, the largest family among freshwater teleosts, accounting for 10 % of total fish production. Specifically, the common carp is cultured in more than 100 countries in worldwide and accounts for over 3 million metric tons of total annual freshwater fish production. The population of common carp (C. carpio) is declining in freshwater reservoirs because of various human activities, such as overfishing, pollution, hybridization with domestic carp, and loss of breeding grounds because of habitat degradation.\n\nResultsIn total, 30 specimens were collected from each of four different locations (WH1, WH2, WH3 and WH4) in the reservoir. Five random decamer primers were used to assay polymorphisms within and between the population of C. carpio. A total of 60 bands were produced by these primers, out of which 50 bands were polymorphic and 10 bands were monomorphic. The mean highest polymorphism (100 %) was observed in the specimen collected from WHS4 stock, followed by 89.05, 87.62 and 76.66 % of the fish collection from WH3, WH2, and WH4, respectively. Neis genetic distance values ranged from 0.0006 to 0.1005. Highest and lowest genetic distance were 0.1005 and 0.006 in fish collected from WH1 and WH2, respectively. Average value of heterozygosity ranged from 0.3008 to 0.3748. A C. carpio UPGMA dendrogram was constructed to observe fish phylogeny. Phylogenetic clusters by RAPD indicated that fish stock of WH2, WH3, and WH4 were closely related to each other.\n\nConclusionIt was concluded that RAPD analysis can be successfully used as a marker to generate information regarding the percent homology within stock of common carp, which may be used to trace the progeny to the parents and is helpful for the improvement of breeding programs.

genetics↗

bioRxiv2018

Replication fork collapse at a protein-DNA roadblock leads to fork reversal, promoted by the RecQ helicase

There are numerous impediments that DNA replication can encounter while copying a genome, including the many proteins that bind DNA. Collapse of the replication fork at a protein roadblock must be dealt with to enable replication to eventually restart; failure to do so efficiently leads to mutation or cell death. Several prospective models have been proposed that process a stalled or collapsed replication fork. This study shows that replication fork reversal (RFR) is the preferred pathway for dealing with a collapsed fork in Escherichia coli, along with exonuclease activity that digests the two nascent DNA strands. RFR moves the Y-shaped replication fork DNA away from the site of the blockage and generates a four-way DNA structure, the Holliday junction (HJ). Direct endo-nuclease activity at the replication fork is either slow or does not occur. The protein that had the greatest effect on HJ processing/RFR was found to be the RecQ helicase. RecG and RuvABC both played a lesser role, but did affect the HJ produced: mutations in these known HJ processing enzymes produced longer-lasting HJ intermediates, and delayed replication restart. The SOS response is not induced by the protein-DNA roadblock under these conditions and so does not affect fork processing.\n\nAuthor SummaryTo transfer genetic material to progeny, a cell must replicate its DNA accurately and completely. If a cell does not respond appropriately to inhibitors of the DNA replication process, genetic mutation and cell death will occur. Previous works have shown that protein-DNA complexes are the greatest source of replication fork stalling and collapse in bacteria. This work examines how the cell deals with replication fork collapse at a persistent protein blockage, at a specific locus on the chromosome of Escherichia coli. Cells were found to process the DNA at the replication fork, moving the branch point away from the site of blockage by replication fork reversal and exonuclease activity. Our data indicate that it is the RecQ helicase that has the main controlling role in this process, and not the proteins RecG and RuvABC, as currently understood. RecQ homologs have been shown to be involved in replication fork processing in eukaryotes and their mutation predisposes humans to genome instability and cancer. Our findings suggest that RecQ proteins could play more important role in replication fork reversal than previously understood, and that this role could be conserved across domains.

microbiology↗

bioRxiv2018

An EST-SSR based genetic linkage map and identification of QTLs for anthracnose disease resistance in water yam (Dioscorea alata L.)

Water yam (Dioscorea alata L.) is one of the most important food yams with wide geographical distribution in tropics. One of the major constraints to water yam production is anthracnose disease caused by a fungus, Colletotrichum gloesporioides (Penz.). There are no economically feasible solutions as chemical sprays or cultural practices, such as crop rotation are seldom convenient for smallholder farmers for sustainable control of the disease. Breeding for development of durable genetic resistant varieties is known to offer lasting solution to control endemic disease threats to crop production. However, breeding for resistance to anthracnose has been slow considering the biological constraints related to the heterozygous and vegetative propagation of the crop. The development of saturated linkage maps with high marker density, such as SSRs, followed by identification of QTLs can accelerate the speed and precision of resistance breeding in water yam. A total of 380 EST-SSRs were used to generate a saturated linkage map. About 60.19% of SSRs showed Mendelian segregation pattern, however, it had no effect on the construction of linkage map. All 380 EST-SSRs were mapped into 20 linkage groups covering a total length of 2559.66 cM, which agrees with the diploid nature (2n = 2x = 20) of the parents used in the cross. Majority of the markers were mapped on linkage group 1 comprising of 97 EST-SSRs. This is the first genetic linkage map of water yam constructed using EST-SSRs. QTL localization was based on phenotypic data collected over a 3-year period of inoculating the mapping population with the most virulent strain of C. gloeosporoides from West Africa. Using the mean permutation value of LOD scores as threshold value for declaring a putative QTL on all linkage groups, one QTL was consistently observed on linkage group (LG) 14 in all the three years and average score data. This QTL was found at position interval of 71.12 - 84.76 cM explaining 68.94% of the total phenotypic variation in the average score data. The high marker density allowed identification of QTLs and association for anthracnose disease, which could be validated in other mapping populations and used in marker-assisted breeding in D. alata improvement programmes.

molecular biology↗