Association mapping of flowering and height traits in Germplasm Enhancement of Maize doubled haploid (GEM-DH) lines

USDA-ARS?s Scientific Manuscript database

Flowering and plant and ear height-related traits are extensively studied in maize for three main reasons: 1) ease of obtaining phenotypic measurements, 2) advances in genotyping and sequencing technologies have reduced the cost of genomic information, and 3) the importance of these traits for adapt...

Improvements in the production of doubled haploids in durum wheat (Triticum turgidum L.) through isolated microspore culture.

PubMed

Cistué, Luis; Romagosa, I; Batlle, F; Echávarri, B

2009-05-01

The objective of this study was to produce durum wheat doubled haploid (DH) plants through the induction of microspore embryogenesis. The microspore culture technique was improved to maximize production of green plants per spike using three commercial cultivars. Studies on factors such as induction media composition, induction media support and the stage and growth of donor plants were carried out in order to develop an efficient protocol to regenerate green and fertile DH plants. Microspores were plated on a C(17) induction culture medium with ovary co-culture and a supplement of glutathione plus glutamine; 300 g/l Ficoll Type-400 was incorporated to the induction medium support. Donor plants were fertilized with a combination of macro and microelements. With the cultivars 'Ciccio' and 'Claudio' an average of 36.5 and 148.5 fertile plants were produced, respectively, from 1,000 anthers inoculated. This technique was then used to produce fertile DH plants of potential agronomic interest from a collection of ten F(1) crosses involving cultivars of high breeding value. From these crosses 849 green plants were obtained and seed was harvested from 702 plants indicating that 83% of green plants were fertile and therefore were spontaneously DHs. No aneuploid plant was obtained. The 702 plants yielded enough seeds to be field tested. One of the DH lines obtained by microspore embryogenesis, named 'Lanuza', has been sent to the Spanish Plant Variety Office for Registration by the Batlle Seed Company. This protocol can be used instead of the labor-intensive inter-generic crossing with maize as an economically feasible method to obtain DHs for most crosses involving the durum wheat cultivars grown in Spain.

Comparative quantitative trait loci for silique length and seed weight in Brassica napus.

PubMed

Fu, Ying; Wei, Dayong; Dong, Hongli; He, Yajun; Cui, Yixin; Mei, Jiaqin; Wan, Huafang; Li, Jiana; Snowdon, Rod; Friedt, Wolfgang; Li, Xiaorong; Qian, Wei

2015-09-23

Silique length (SL) and seed weight (SW) are important yield-associated traits in rapeseed (Brassica napus). Although many quantitative trait loci (QTL) for SL and SW have been identified in B. napus, comparative analysis for those QTL is seldom performed. In the present study, 20 and 21 QTL for SL and SW were identified in doubled haploid (DH) and DH-derived reconstructed F2 populations in rapeseed, explaining 55.1-74.3% and 24.4-62.9% of the phenotypic variation across three years, respectively. Of which, 17 QTL with partially or completely overlapped confidence interval on chromosome A09, were homologous with two overlapped QTL on chromosome C08 by aligning QTL confidence intervals with the reference genomes of Brassica crops. By high density selective genotyping of DH lines with extreme phenotypes, using a Brassica single-nucleotide polymorphism (SNP) array, the QTL on chromosome A09 was narrowed, and aligned into 1.14-Mb region from 30.84 to 31.98 Mb on chromosome R09 of B. rapa and 1.05-Mb region from 27.21 to 28.26 Mb on chromosome A09 of B. napus. The alignment of QTL with Brassica reference genomes revealed homologous QTL on A09 and C08 for SL. The narrowed QTL region provides clues for gene cloning and breeding cultivars by marker-assisted selection.

Mapping resistance to the Ug99 race group of the stem rust pathogen in a spring wheat landrace

USDA-ARS?s Scientific Manuscript database

Wheat landrace PI 374670 has seedling and field resistance to stem rust caused by Puccinia graminis f. sp tritici Eriks. & E. Henn (Pgt) race TTKSK. To elucidate the inheritance of resistance, 216 BC1F2 families, 192 double haploid (DH) lines, and 185 recombinant inbred lines (RILs) were developed b...

Characterization of a wheat mutant missing low-molecular-weight glutenin subunits encoded by the B-genome

USDA-ARS?s Scientific Manuscript database

DH20, a new wheat mutant missing low-molecular weight glutenin subunits encoded by the Glu-B3 locus, was discovered among double haploid lines obtained from a cross between the Korean wheat cultivars Keumkang and Olgeuru. Absence of the Glu-B3 LMW-GS proteins was determined by one-dimensional gel e...

Early growth stages salinity stress tolerance in CM72 x Gairdner doubled haploid barley population

PubMed Central

Angessa, Tefera Tolera; Zhang, Xiao-Qi; Zhou, Gaofeng; Broughton, Sue; Zhang, Wenying

2017-01-01

A doubled haploid (DH) population of barley (Hordeum vulgare L.) generated from salinity tolerant genotype CM72 and salinity sensitive variety Gairdner was studied for salinity stress tolerance at germination, seedling emergence and first leaf full expansion growth stages. Germination study was conducted with deionized water, 150 mM and 300 mM NaCl treatments. Seedling stage salinity tolerance was conducted with three treatments: control, 150 mM NaCl added at seedling emergence and first leaf full expansion growth stages. Results from this study revealed transgressive phenotypic segregations for germination percentage and biomass at seedling stage. Twelve QTL were identified on chromosomes 2H–6H each explaining 10–25% of the phenotypic variations. A QTL located at 176.5 cM on chromosome 3H was linked with fresh weight per plant and dry weight per plant in salinity stress induced at first leaf full expansion growth stage, and dry weight per plant in salinity stress induced at seedling emergence. A stable QTL for germination at both 150 and 300 mM salinity stress was mapped on chromosome 2H but distantly located from a QTL linked with seedling stage salinity stress tolerance. QTL, associated markers and genotypes identified in this study play important roles in developing salinity stress tolerant barley varieties. PMID:28640858

Brassinosteroid and gibberellin control of seedling traits in maize (Zea mays L.).

PubMed

Hu, Songlin; Sanchez, Darlene L; Wang, Cuiling; Lipka, Alexander E; Yin, Yanhai; Gardner, Candice A C; Lübberstedt, Thomas

2017-10-01

In this study, we established two doubled haploid (DH) libraries with a total of 207 DH lines. We applied BR and GA inhibitors to all DH lines at seedling stage and measured seedling BR and GA inhibitor responses. Moreover, we evaluated field traits for each DH line (untreated). We conducted genome-wide association studies (GWAS) with 62,049 genome wide SNPs to explore the genetic control of seedling traits by BR and GA. In addition, we correlate seedling stage hormone inhibitor response with field traits. Large variation for BR and GA inhibitor response and field traits was observed across these DH lines. Seedling stage BR and GA inhibitor response was significantly correlate with yield and flowering time. Using three different GWAS approaches to balance false positive/negatives, multiple SNPs were discovered to be significantly associated with BR/GA inhibitor responses with some localized within gene models. SNPs from gene model GRMZM2G013391 were associated with GA inhibitor response across all three GWAS models. This gene is expressed in roots and shoots and was shown to regulate GA signaling. These results show that BRs and GAs have a great impact for controlling seedling growth. Gene models from GWAS results could be targets for seeding traits improvement. Copyright © 2017 Elsevier B.V. All rights reserved.

Drought-tolerant QTL qVDT11 leads to stable tiller formation under drought stress conditions in rice.

PubMed

Kim, Tae-Heon; Hur, Yeon-Jae; Han, Sang-Ik; Cho, Jun-Hyun; Kim, Kyung-Min; Lee, Jong-Hee; Song, You-Chun; Kwon, Yeong-Up; Shin, Dongjin

2017-03-01

Drought is an important limiting factor for rice production, but the genetic mechanisms of drought tolerance is poorly understood. Here, we screened 218 rice varieties to identify 32 drought-tolerant varieties. The variety Samgang exhibited strong drought tolerance and stable yield in rain-fed conditions and was selected for further study. To identify QTLs for drought tolerance, we examined visual drought tolerance (VDT) and relative water content (RWC) phenotypes in a doubled haploid (DH) population of 101 individuals derived from a cross between Samgang and Nagdong (a drought-sensitive variety). Three QTLs from Samgang were identified for VDT and explained 41.8% of the phenotypic variance. In particular, qVDT11 contributed 20.3% of the phenotypic variance for RWC. To determine QTL effects on drought tolerance in rain-fed paddy conditions, seven DH lines were selected according to the number of QTLs they contained. Of the drought-tolerance-associated QTLs, qVDT2 and qVDT6 did not affect tiller formation, but qVDT11 increased tiller number. Tiller formation was most stable when qVDT2 and qVDT11 were combined. DH lines with both of these drought-tolerance-associated QTLs exhibited the most stable tiller formation. Together, these results suggest that qVDT11 is important for drought tolerance and stable tiller formation in rain-fed paddy fields. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Multigenic Control of Pod Shattering Resistance in Chinese Rapeseed Germplasm Revealed by Genome-Wide Association and Linkage Analyses

PubMed Central

Liu, Jia; Wang, Jun; Wang, Hui; Wang, Wenxiang; Zhou, Rijin; Mei, Desheng; Cheng, Hongtao; Yang, Juan; Raman, Harsh; Hu, Qiong

2016-01-01

The majority of rapeseed cultivars shatter seeds upon maturity especially under hot-dry and windy conditions, reducing yield and gross margin return to growers. Here, we identified quantitative trait loci (QTL) for resistance to pod shatter in an unstructured diverse panel of 143 rapeseed accessions, and two structured populations derived from bi-parental doubled haploid (DH) and inter-mated (IF2) crosses derived from R1 (resistant to pod shattering) and R2 (prone to pod shattering) accessions. Genome-wide association analysis identified six significant QTL for resistance to pod shatter located on chromosomes A01, A06, A07, A09, C02, and C05. Two of the QTL, qSRI.A09 delimited with the SNP marker Bn-A09-p30171993 (A09) and qSRI.A06 delimited with the SNP marker Bn-A06-p115948 (A06) could be repeatedly detected across environments in a diversity panel, DH and IF2 populations, suggesting that at least two loci on chromosomes A06 and A09 were the main contributors to pod shatter resistance in Chinese germplasm. Significant SNP markers identified in this study especially those that appeared repeatedly across environments provide a cost-effective and an efficient method for introgression and pyramiding of favorable alleles for pod shatter resistance via marker-assisted selection in rapeseed improvement programs. PMID:27493651

Investigation of the Genetic Diversity and Quantitative Trait Loci Accounting for Important Agronomic and Seed Quality Traits in Brassica carinata

PubMed Central

Zhang, Wenshan; Hu, Dandan; Raman, Rosy; Guo, Shaomin; Wei, Zili; Shen, Xueqi; Meng, Jinling; Raman, Harsh; Zou, Jun

2017-01-01

Brassica carinata (BBCC) is an allotetraploid in Brassicas with unique alleles for agronomic traits and has huge potential as source for biodiesel production. To investigate the genome-wide molecular diversity, population structure and linkage disequilibrium (LD) pattern in this species, we genotyped a panel of 81 accessions of B. carinata with genotyping by sequencing approach DArTseq, generating a total of 54,510 polymorphic markers. Two subpopulations were exhibited in the B. carinata accessions. The average distance of LD decay (r2 = 0.1) in B subgenome (0.25 Mb) was shorter than that of C subgenome (0.40 Mb). Genome-wide association analysis (GWAS) identified a total of seven markers significantly associated with five seed quality traits in two experiments. To further identify the quantitative trait loci (QTL) for important agronomic and seed quality traits, we phenotyped a doubled haploid (DH) mapping population derived from the “YW” cross between two parents (Y-BcDH64 and W-BcDH76) representing from the two subpopulations. The YW DH population and its parents were grown in three contrasting environments; spring (Hezheng and Xining, China), semi-winter (Wuhan, China), and spring (Wagga Wagga, Australia) across 5 years for QTL mapping. Genetic bases of phenotypic variation in seed yield and its seven related traits, and six seed quality traits were determined. A total of 282 consensus QTL accounting for these traits were identified including nine major QTL for flowering time, oleic acid, linolenic acid, pod number of main inflorescence, and seed weight. Of these, 109 and 134 QTL were specific to spring and semi-winter environment, respectively, while 39 consensus QTL were identified in both contrasting environments. Two QTL identified for linolenic acid (B3) and erucic acid (C7) were validated in the diverse lines used for GWAS. A total of 25 QTL accounting for flowering time, erucic acid, and oleic acid were aligned to the homologous QTL or candidate gene regions in the C genome of B. napus. These results would not only provide insights for genetic improvement of this species, but will also identify useful genetic variation hidden in the Cc subgenome of B. carinata to improve canola cultivars. PMID:28484482

Development of a multiple bulked segregant analysis (MBSA) method used to locate a new stem rust resistance gene (Sr54) in the winter wheat cultivar Norin 40.

PubMed

Ghazvini, Habibollah; Hiebert, Colin W; Thomas, Julian B; Fetch, Thomas

2013-02-01

An important aspect of studying putative new genes in wheat is determining their position on the wheat genetic map. The primary difficulty in mapping genes is determining which chromosome carries the gene of interest. Several approaches have been developed to address this problem, each with advantages and disadvantages. Here we describe a new approach called multiple bulked segregant analysis (MBSA). A set of 423 simple sequence repeat (SSR) markers were selected based on profile simplicity, frequency of polymorphism, and distribution across the wheat genome. SSR primers were preloaded in 384-well PCR plates with each primer occupying 16 wells. In practice, 14 wells are reserved for "mini-bulks" that are equivalent to four gametes (e.g. two F(2) individuals) comprised of individuals from a segregated population that have a known homozygous genotype for the gene of interest. The remaining two wells are reserved for the parents of the population. Each well containing a mini-bulk can have one of three allele compositions for each SSR: only the allele from one parent, only the allele from the other parent, or both alleles. Simulation experiments were performed to determine the pattern of mini-bulk allele composition that would indicate putative linkage between the SSR in question and the gene of interest. As a test case, MBSA was employed to locate an unidentified stem rust resistance (Sr) gene in the winter wheat cultivar Norin 40. A doubled haploid (DH) population (n = 267) was produced from hybrids of the cross LMPG-6S/Norin 40. The DH population segregated for a single gene (χ (1:1) (2) = 0.093, p = 0.76) for resistance to Puccinia graminis f.sp. tritici race LCBN. Four resistant DH lines were included in each of the 14 mini-bulks for screening. The Sr gene was successfully located to the long arm of chromosome 2D using MBSA. Further mapping confirmed the chromosome location and revealed that the Sr gene was located in a linkage block that may represent an alien translocation. The new Sr gene was designated as Sr54.

Quantitative Trait Locus Analysis for Deep-Sowing Germination Ability in the Maize IBM Syn10 DH Population

PubMed Central

Liu, Hongjun; Zhang, Lin; Wang, Jiechen; Li, Changsheng; Zeng, Xing; Xie, Shupeng; Zhang, Yongzhong; Liu, Sisi; Hu, Songlin; Wang, Jianhua; Lee, Michael; Lübberstedt, Thomas; Zhao, Guangwu

2017-01-01

Deep-sowing is an effective measure to ensure seeds absorbing water from deep soil layer and emerging normally in arid and semiarid regions. However, existing varieties demonstrate poor germination ability in deep soil layer and some key quantitative trait loci (QTL) or genes related to deep-sowing germination ability remain to be identified and analyzed. In this study, a high-resolution genetic map based on 280 lines of the intermated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population which comprised 6618 bin markers was used for the QTL analysis of deep-sowing germination related traits. The results showed significant differences in germination related traits under deep-sowing condition (12.5 cm) and standard-germination condition (2 cm) between two parental lines. In total, 8, 11, 13, 15, and 18 QTL for germination rate, seedling length, mesocotyl length, plumule length, and coleoptile length were detected for the two sowing conditions, respectively. These QTL explained 2.51–7.8% of the phenotypic variance with LOD scores ranging from 2.52 to 7.13. Additionally, 32 overlapping QTL formed 11 QTL clusters on all chromosomes except for chromosome 8, indicating the minor effect genes have a pleiotropic role in regulating various traits. Furthermore, we identified six candidate genes related to deep-sowing germination ability, which were co-located in the cluster regions. The results provide a basis for molecular marker assisted breeding and functional study in deep-sowing germination ability of maize. PMID:28588594

Quantitative Trait Locus Analysis for Deep-Sowing Germination Ability in the Maize IBM Syn10 DH Population.

PubMed

Liu, Hongjun; Zhang, Lin; Wang, Jiechen; Li, Changsheng; Zeng, Xing; Xie, Shupeng; Zhang, Yongzhong; Liu, Sisi; Hu, Songlin; Wang, Jianhua; Lee, Michael; Lübberstedt, Thomas; Zhao, Guangwu

2017-01-01

Deep-sowing is an effective measure to ensure seeds absorbing water from deep soil layer and emerging normally in arid and semiarid regions. However, existing varieties demonstrate poor germination ability in deep soil layer and some key quantitative trait loci (QTL) or genes related to deep-sowing germination ability remain to be identified and analyzed. In this study, a high-resolution genetic map based on 280 lines of the intermated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population which comprised 6618 bin markers was used for the QTL analysis of deep-sowing germination related traits. The results showed significant differences in germination related traits under deep-sowing condition (12.5 cm) and standard-germination condition (2 cm) between two parental lines. In total, 8, 11, 13, 15, and 18 QTL for germination rate, seedling length, mesocotyl length, plumule length, and coleoptile length were detected for the two sowing conditions, respectively. These QTL explained 2.51-7.8% of the phenotypic variance with LOD scores ranging from 2.52 to 7.13. Additionally, 32 overlapping QTL formed 11 QTL clusters on all chromosomes except for chromosome 8, indicating the minor effect genes have a pleiotropic role in regulating various traits. Furthermore, we identified six candidate genes related to deep-sowing germination ability, which were co-located in the cluster regions. The results provide a basis for molecular marker assisted breeding and functional study in deep-sowing germination ability of maize.

Fixation Probability in a Haploid-Diploid Population

PubMed Central

Bessho, Kazuhiro; Otto, Sarah P.

2017-01-01

Classical population genetic theory generally assumes either a fully haploid or fully diploid life cycle. However, many organisms exhibit more complex life cycles, with both free-living haploid and diploid stages. Here we ask what the probability of fixation is for selected alleles in organisms with haploid-diploid life cycles. We develop a genetic model that considers the population dynamics using both the Moran model and Wright–Fisher model. Applying a branching process approximation, we obtain an accurate fixation probability assuming that the population is large and the net effect of the mutation is beneficial. We also find the diffusion approximation for the fixation probability, which is accurate even in small populations and for deleterious alleles, as long as selection is weak. These fixation probabilities from branching process and diffusion approximations are similar when selection is weak for beneficial mutations that are not fully recessive. In many cases, particularly when one phase predominates, the fixation probability differs substantially for haploid-diploid organisms compared to either fully haploid or diploid species. PMID:27866168

Mating system and gene flow in the red seaweed Gracilaria gracilis: effect of haploid-diploid life history and intertidal rocky shore landscape on fine-scale genetic structure.

PubMed

Engel, C R; Destombe, C; Valero, M

2004-04-01

The impact of haploid-diploidy and the intertidal landscape on a fine-scale genetic structure was explored in a red seaweed Gracilaria gracilis. The pattern of genetic structure was compared in haploid and diploid stages at a microgeographic scale (< 5 km): a total of 280 haploid and 296 diploid individuals located in six discrete, scattered rock pools were genotyped using seven microsatellite loci. Contrary to the theoretical expectation of predominantly endogamous mating systems in haploid-diploid organisms, G. gracilis showed a clearly allogamous mating system. Although within-population allele frequencies were similar between haploids and diploids, genetic differentiation among haploids was more than twice that of diploids, suggesting that there may be a lag between migration and (local) breeding due to the long generation times in G. gracilis. Weak, but significant, population differentiation was detected in both haploids and diploids and varied with landscape features, and not with geographic distance. Using an assignment test, we establish that effective migration rates varied according to height on the shore. In this intertidal species, biased spore dispersal may occur during the transport of spores and gametes at low tide when small streams flow from high- to lower-shore pools. The longevity of both haploid and diploid free-living stages and the long generation times typical of G. gracilis populations may promote the observed pattern of high genetic diversity within populations relative to that among populations.

Quantitative trait loci controlling leaf appearance and curd initiation of cauliflower in relation to temperature.

PubMed

Hasan, Yaser; Briggs, William; Matschegewski, Claudia; Ordon, Frank; Stützel, Hartmut; Zetzsche, Holger; Groen, Simon; Uptmoor, Ralf

2016-07-01

QTL regions on chromosomes C06 and C09 are involved in temperature dependent time to curd induction in cauliflower. Temperature is the main environmental factor influencing curding time of cauliflower (Brassica oleracea var. botrytis). Temperatures above 20-22 °C inhibit development towards curding even in many summer cultivars. To identify quantitative trait loci (QTL) controlling curding time and its related traits in a wide range of different temperature regimes from 12 to 27 °C, a doubled haploid (DH) mapping population segregating for curding time was developed and days to curd initiation (DCI), leaf appearance rate (LAR), and final leaf number (FLN) were measured. The population was genotyped with 176 single nucleotide polymorphism (SNP) markers. Composite interval mapping (CIM) revealed repeatedly detected QTL for DCI on C06 and C09. The estimated additive effect increased at high temperatures. Significant QTL × environment interactions (Q × E) for FLN and DCI on C06 and C09 suggest that these hotspot regions have major influences on temperature mediated curd induction. 25 % of the DH lines did not induce curds at temperatures higher than 22 °C. Applying a binary model revealed a QTL with LOD >15 on C06. Nearly all lines carrying the allele of the reliable early maturing parental line (PL) on that locus induced curds at high temperatures while only half of the DH lines carrying the allele of the unreliable PL reached the generative phase during the experiment. Large variation in LAR was observed. QTL for LAR were detected repeatedly in several environments on C01, C04 and C06. Negative correlations between LAR and DCI and QTL co-localizations on C04 and C06 suggest that LAR has also effects on development towards curd induction.

Fixation Probability in a Haploid-Diploid Population.

PubMed

Bessho, Kazuhiro; Otto, Sarah P

2017-01-01

Classical population genetic theory generally assumes either a fully haploid or fully diploid life cycle. However, many organisms exhibit more complex life cycles, with both free-living haploid and diploid stages. Here we ask what the probability of fixation is for selected alleles in organisms with haploid-diploid life cycles. We develop a genetic model that considers the population dynamics using both the Moran model and Wright-Fisher model. Applying a branching process approximation, we obtain an accurate fixation probability assuming that the population is large and the net effect of the mutation is beneficial. We also find the diffusion approximation for the fixation probability, which is accurate even in small populations and for deleterious alleles, as long as selection is weak. These fixation probabilities from branching process and diffusion approximations are similar when selection is weak for beneficial mutations that are not fully recessive. In many cases, particularly when one phase predominates, the fixation probability differs substantially for haploid-diploid organisms compared to either fully haploid or diploid species. Copyright © 2017 by the Genetics Society of America.

QTL mapping identifies a major locus for resistance in wheat to Sunn pest (Eurygaster integriceps) feeding at the vegetative growth stage.

PubMed

Emebiri, L C; Tan, M-K; El-Bouhssini, M; Wildman, O; Jighly, A; Tadesse, W; Ogbonnaya, F C

2017-02-01

This research provides the first report of a major locus controlling wheat resistance to Sunn pest. It developed and validated SNP markers that will be useful for marker-assisted selection. Sunn pest (Eurygaster integriceps Puton) is the most destructive insect pest of bread wheat and durum wheat in West and Central Asia and East Europe. Breeding for resistance at the vegetative stage of growth is vital in reducing the damage caused by overwintered adult populations that feed on shoot and leaves of seedlings, and in reducing the next generation of pest populations (nymphs and adults), which can cause damage to grain quality by feeding on spikes. In the present study, two doubled haploid (DH) populations involving resistant landraces from Afghanistan were genotyped with the 90k SNP iSelect assay and candidate gene-based KASP markers. The DH lines and parents were phenotyped for resistance to Sunn pest feeding, using artificial infestation cages at Terbol station, in Lebanon, over three years. Quantitative trait locus (QTL) analysis identified a single major locus on chromosome 4BS in the two populations, with the resistance allele derived from the landrace accessions, IG139431 and IG139883. The QTL explained a maximum of 42 % of the phenotypic variation in the Cham6 × IG139431 and 56 % in the Cham6 × IG139883 populations. SNP markers closest to the QTL showed high similarity to rice genes that putatively encode proteins for defense response to herbivory and wounding. The markers were validated in a large, unrelated population of parental wheat genotypes. All wheat lines carrying the 'C-G' haplotype at the identified SNPs were resistant, suggesting that selection based on a haplotype of favourable alleles would be effective in predicting resistance status of unknown genotypes.

Mapping resistance to the Ug99 race group of the stem rust pathogen in a spring wheat landrace.

PubMed

Babiker, E M; Gordon, T C; Chao, S; Newcomb, M; Rouse, M N; Jin, Y; Wanyera, R; Acevedo, M; Brown-Guedira, G; Williamson, S; Bonman, J M

2015-04-01

A new gene for Ug99 resistance from wheat landrace PI 374670 was detected on the long arm of chromosome 7A. Wheat landrace PI 374670 has seedling and field resistance to stem rust caused by Puccinia graminis f. sp tritici Eriks. & E. Henn (Pgt) race TTKSK. To elucidate the inheritance of resistance, 216 BC1F2 families, 192 double haploid (DH) lines, and 185 recombinant inbred lines (RILs) were developed by crossing PI 374670 and the susceptible line LMPG-6. The parents and progeny were evaluated for seedling resistance to Pgt races TTKSK, MCCFC, and TPMKC. The DH lines were tested in field stem rust nurseries in Kenya and Ethiopia. The DH lines were genotyped with the 90K wheat iSelect SNP genotyping platform. Goodness-of-fit tests indicated that a single dominant gene in PI 374670 conditioned seedling resistance to the three Pgt races. The seedling resistance locus mapped to the long arm of chromosome 7A and this result was verified in the RIL population screened with the flanking SNP markers using KASP assays. In the same region, a major QTL for field resistance was detected in a 7.7 cM interval and explained 34-54 and 29-36% of the variation in Kenya and Ethiopia, respectively. Results from tests with specific Pgt races and the csIH81 marker showed that the resistance was not due to Sr22. Thus, a new stem rust resistance gene or allele, either closely linked or allelic to Sr15, is responsible for the seedling and field resistance of PI 374670 to Ug99.

Chromosome Doubling of Microspore-Derived Plants from Cabbage (Brassica oleracea var. capitata L.) and Broccoli (Brassica oleracea var. italica L.)

PubMed Central

Yuan, Suxia; Su, Yanbin; Liu, Yumei; Li, Zhansheng; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao; Sun, Peitian

2015-01-01

Chromosome doubling of microspore-derived plants is an important factor in the practical application of microspore culture technology because breeding programs require a large number of genetically stable, homozygous doubled haploid plants with a high level of fertility. In the present paper, 29 populations of microspore-derived plantlets from cabbage (Brassica oleracea var. capitata) and broccoli (Brassica oleracea var. italica) were used to study the ploidy level and spontaneous chromosome doubling of these populations, the artificial chromosome doubling induced by colchicine, and the influence of tissue culture duration on the chromosomal ploidy of the microspore-derived regenerants. Spontaneous chromosome doubling occurred randomly and was genotype dependent. In the plant populations derived from microspores, there were haploids, diploids, and even a low frequency of polyploids and mixed-ploidy plantlets. The total spontaneous doubling in the 14 cabbage populations ranged from 0 to 76.9%, compared with 52.2 to 100% in the 15 broccoli populations. To improve the rate of chromosome doubling, an efficient and reliable artificial chromosome doubling protocol (i.e., the immersion of haploid plantlet roots in a colchicine solution) was developed for cabbage and broccoli microspore-derived haploids. The optimal chromosome doubling of the haploids was obtained with a solution of 0.2% colchicine for 9–12 h or 0.4% colchicine for 3–9 h for cabbage and 0.05% colchicine for 6–12 h for broccoli. This protocol produced chromosome doubling in over 50% of the haploid genotypes for most of the populations derived from cabbage and broccoli. Notably, after 1 or more years in tissue culture, the chromosomes of the haploids were doubled, and most of the haploids turned into doubled haploid or mixed-ploidy plants. This is the first report indicating that tissue culture duration can change the chromosomal ploidy of microspore-derived regenerants. PMID:26734028

Chromosome Doubling of Microspore-Derived Plants from Cabbage (Brassica oleracea var. capitata L.) and Broccoli (Brassica oleracea var. italica L.).

PubMed

Yuan, Suxia; Su, Yanbin; Liu, Yumei; Li, Zhansheng; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao; Sun, Peitian

2015-01-01

Chromosome doubling of microspore-derived plants is an important factor in the practical application of microspore culture technology because breeding programs require a large number of genetically stable, homozygous doubled haploid plants with a high level of fertility. In the present paper, 29 populations of microspore-derived plantlets from cabbage (Brassica oleracea var. capitata) and broccoli (Brassica oleracea var. italica) were used to study the ploidy level and spontaneous chromosome doubling of these populations, the artificial chromosome doubling induced by colchicine, and the influence of tissue culture duration on the chromosomal ploidy of the microspore-derived regenerants. Spontaneous chromosome doubling occurred randomly and was genotype dependent. In the plant populations derived from microspores, there were haploids, diploids, and even a low frequency of polyploids and mixed-ploidy plantlets. The total spontaneous doubling in the 14 cabbage populations ranged from 0 to 76.9%, compared with 52.2 to 100% in the 15 broccoli populations. To improve the rate of chromosome doubling, an efficient and reliable artificial chromosome doubling protocol (i.e., the immersion of haploid plantlet roots in a colchicine solution) was developed for cabbage and broccoli microspore-derived haploids. The optimal chromosome doubling of the haploids was obtained with a solution of 0.2% colchicine for 9-12 h or 0.4% colchicine for 3-9 h for cabbage and 0.05% colchicine for 6-12 h for broccoli. This protocol produced chromosome doubling in over 50% of the haploid genotypes for most of the populations derived from cabbage and broccoli. Notably, after 1 or more years in tissue culture, the chromosomes of the haploids were doubled, and most of the haploids turned into doubled haploid or mixed-ploidy plants. This is the first report indicating that tissue culture duration can change the chromosomal ploidy of microspore-derived regenerants.

Maximization of Markers Linked in Coupling for Tetraploid Potatoes via Monoparental Haploids

PubMed Central

Bartkiewicz, Annette M.; Chilla, Friederike; Terefe-Ayana, Diro; Lübeck, Jens; Strahwald, Josef; Tacke, Eckhard; Hofferbert, Hans-Reinhard; Linde, Marcus; Debener, Thomas

2018-01-01

Haploid potato populations derived from a single tetraploid donor constitute an efficient strategy to analyze markers segregating from a single donor genotype. Analysis of marker segregation in populations derived from crosses between polysomic tetraploids is complicated by a maximum of eight segregating alleles, multiple dosages of the markers and problems related to linkage analysis of marker segregation in repulsion. Here, we present data on two monoparental haploid populations generated by prickle pollination of two tetraploid cultivars with Solanum phureja and genotyped with the 12.8 k SolCAP single nucleotide polymorphism (SNP) array. We show that in a population of monoparental haploids, the number of biallelic SNP markers segregating in linkage to loci from the tetraploid donor genotype is much larger than in putative crosses of this genotype to a diverse selection of 125 tetraploid cultivars. Although this strategy is more laborious than conventional breeding, the generation of haploid progeny for efficient marker analysis is straightforward if morphological markers and flow cytometry are utilized to select true haploid progeny. The level of introgressed fragments from S. phureja, the haploid inducer, is very low, supporting its suitability for genetic analysis. Mapping with single-dose markers allowed the analysis of quantitative trait loci (QTL) for four phenotypic traits. PMID:29868076

Maize Haploid Induction and Doubling II – Experience with Exotic and Elite Maize Populations

USDA-ARS?s Scientific Manuscript database

As a follow-up to our previous study, second year information will be presented addressing questions on haploid induction and doubling, utilizing exotic and elite maize. These projects result from collaborations between Iowa State Doubled Haploid Facility (http://www.plantbreeding.iastate.edu/DHF/D...

Maize Haploid Induction and Doubling – Recent Experience with Exotic and Elite Maize Populations

USDA-ARS?s Scientific Manuscript database

Experience from three maize research projects utilizing the haploid inducer RWS x RWK-76 from the University of Hohenheim will be summarized. These projects result from collaborations between Iowa State Doubled Haploid Facility (http://www.plantbreeding.iastate.edu/DHF/DHF.htm) researchers and USDA...

The effects of quantitative fecundity in the haploid stage on reproductive success and diploid fitness in the aquatic peat moss Sphagnum macrophyllum

PubMed Central

Johnson, M G; Shaw, A J

2016-01-01

A major question in evolutionary biology is how mating patterns affect the fitness of offspring. However, in animals and seed plants it is virtually impossible to investigate the effects of specific gamete genotypes. In bryophytes, haploid gametophytes grow via clonal propagation and produce millions of genetically identical gametes throughout a population. The main goal of this research was to test whether gamete identity has an effect on the fitness of their diploid offspring in a population of the aquatic peat moss Sphagnum macrophyllum. We observed a heavily male-biased sex ratio in gametophyte plants (ramets) and in multilocus microsatellite genotypes (genets). There was a steeper relationship between mating success (number of different haploid mates) and fecundity (number of diploid offspring) for male genets compared with female genets. At the sporophyte level, we observed a weak effect of inbreeding on offspring fitness, but no effect of brood size (number of sporophytes per maternal ramet). Instead, the identities of the haploid male and haploid female parents were significant contributors to variance in fitness of sporophyte offspring in the population. Our results suggest that intrasexual gametophyte/gamete competition may play a role in determining mating success in this population. PMID:26905464

The effects of quantitative fecundity in the haploid stage on reproductive success and diploid fitness in the aquatic peat moss Sphagnum macrophyllum.

PubMed

Johnson, M G; Shaw, A J

2016-06-01

A major question in evolutionary biology is how mating patterns affect the fitness of offspring. However, in animals and seed plants it is virtually impossible to investigate the effects of specific gamete genotypes. In bryophytes, haploid gametophytes grow via clonal propagation and produce millions of genetically identical gametes throughout a population. The main goal of this research was to test whether gamete identity has an effect on the fitness of their diploid offspring in a population of the aquatic peat moss Sphagnum macrophyllum. We observed a heavily male-biased sex ratio in gametophyte plants (ramets) and in multilocus microsatellite genotypes (genets). There was a steeper relationship between mating success (number of different haploid mates) and fecundity (number of diploid offspring) for male genets compared with female genets. At the sporophyte level, we observed a weak effect of inbreeding on offspring fitness, but no effect of brood size (number of sporophytes per maternal ramet). Instead, the identities of the haploid male and haploid female parents were significant contributors to variance in fitness of sporophyte offspring in the population. Our results suggest that intrasexual gametophyte/gamete competition may play a role in determining mating success in this population.

Germplasm enhancement of maize: A look into haploid induction and chromosomal doubling of haploids from temperate-adapted tropical sources

USDA-ARS?s Scientific Manuscript database

Doubled haploid technology is used to develop completely homozygous inbred lines, where each of the chromatids making up a chromosome pair are identical. Two inbred lines, PHB47 and PHZ51, were used to make backcrosses to 18 maize landraces, generating 36 populations. The landraces were chosen bas...

Monte Carlo simulations on marker grouping and ordering.

PubMed

Wu, J; Jenkins, J; Zhu, J; McCarty, J; Watson, C

2003-08-01

Four global algorithms, maximum likelihood (ML), sum of adjacent LOD score (SALOD), sum of adjacent recombinant fractions (SARF) and product of adjacent recombinant fraction (PARF), and one approximation algorithm, seriation (SER), were used to compare the marker ordering efficiencies for correctly given linkage groups based on doubled haploid (DH) populations. The Monte Carlo simulation results indicated the marker ordering powers for the five methods were almost identical. High correlation coefficients were greater than 0.99 between grouping power and ordering power, indicating that all these methods for marker ordering were reliable. Therefore, the main problem for linkage analysis was how to improve the grouping power. Since the SER approach provided the advantage of speed without losing ordering power, this approach was used for detailed simulations. For more generality, multiple linkage groups were employed, and population size, linkage cutoff criterion, marker spacing pattern (even or uneven), and marker spacing distance (close or loose) were considered for obtaining acceptable grouping powers. Simulation results indicated that the grouping power was related to population size, marker spacing distance, and cutoff criterion. Generally, a large population size provided higher grouping power than small population size, and closely linked markers provided higher grouping power than loosely linked markers. The cutoff criterion range for achieving acceptable grouping power and ordering power differed for varying cases; however, combining all situations in this study, a cutoff criterion ranging from 50 cM to 60 cM was recommended for achieving acceptable grouping power and ordering power for different cases.

A Tourist-like MITE insertion in the upstream region of the BnFLC.A10 gene is associated with vernalization requirement in rapeseed (Brassica napus L.)

PubMed Central

2012-01-01

Background Rapeseed (Brassica napus L.) has spring and winter genotypes adapted to different growing seasons. Winter genotypes do not flower before the onset of winter, thus leading to a longer vegetative growth period that promotes the accumulation and allocation of more resources to seed production. The development of winter genotypes enabled the rapeseed to spread rapidly from southern to northern Europe and other temperate regions of the world. The molecular basis underlying the evolutionary transition from spring- to winter- type rapeseed is not known, however, and needs to be elucidated. Results We fine-mapped the spring environment specific quantitative trait locus (QTL) for flowering time, qFT10-4,in a doubled haploid (DH) mapping population of rapeseed derived from a cross between Tapidor (winter-type) and Ningyou7 (semi-winter) and delimited the qFT10-4 to an 80-kb region on chromosome A10 of B. napus. The BnFLC.A10 gene, an ortholog of FLOWERING LOCUS C (FLC) in Arabidopsis, was cloned from the QTL. We identified 12 polymorphic sites between BnFLC.A10 parental alleles of the TN-DH population in the upstream region and in intron 1. Expression of both BnFLC.A10 alleles decreased during vernalization, but decreased more slowly in the winter parent Tapidor. Haplotyping and association analysis showed that one of the polymorphic sites upstream of BnFLC.A10 is strongly associated with the vernalization requirement of rapeseed (r2 = 0.93, χ2 = 0.50). This polymorphic site is derived from a Tourist-like miniature inverted-repeat transposable element (MITE) insertion/deletion in the upstream region of BnFLC.A10. The MITE sequence was not present in the BnFLC.A10 gene in spring-type rapeseed, nor in ancestral ‘A’ genome species B. rapa genotypes. Our results suggest that the insertion may have occurred in winter rapeseed after B. napus speciation. Conclusions Our findings strongly suggest that (i) BnFLC.A10 is the gene underlying qFT10-4, the QTL for phenotypic diversity of flowering time in the TN-DH population, (ii) the allelic diversity caused by MITE insertion/deletion upstream of BnFLC.A10 is one of the major causes of differentiation of winter and spring genotypes in rapeseed and (iii) winter rapeseed has evolved from spring genotypes through selection pressure at the BnFLC.A10 locus, enabling expanded cultivation of rapeseed along the route of Brassica domestication. PMID:23241244

A Tourist-like MITE insertion in the upstream region of the BnFLC.A10 gene is associated with vernalization requirement in rapeseed (Brassica napus L.).

PubMed

Hou, Jinna; Long, Yan; Raman, Harsh; Zou, Xiaoxiao; Wang, Jing; Dai, Shutao; Xiao, Qinqin; Li, Cong; Fan, Longjiang; Liu, Bin; Meng, Jinling

2012-12-15

Rapeseed (Brassica napus L.) has spring and winter genotypes adapted to different growing seasons. Winter genotypes do not flower before the onset of winter, thus leading to a longer vegetative growth period that promotes the accumulation and allocation of more resources to seed production. The development of winter genotypes enabled the rapeseed to spread rapidly from southern to northern Europe and other temperate regions of the world. The molecular basis underlying the evolutionary transition from spring- to winter- type rapeseed is not known, however, and needs to be elucidated. We fine-mapped the spring environment specific quantitative trait locus (QTL) for flowering time, qFT10-4,in a doubled haploid (DH) mapping population of rapeseed derived from a cross between Tapidor (winter-type) and Ningyou7 (semi-winter) and delimited the qFT10-4 to an 80-kb region on chromosome A10 of B. napus. The BnFLC.A10 gene, an ortholog of FLOWERING LOCUS C (FLC) in Arabidopsis, was cloned from the QTL. We identified 12 polymorphic sites between BnFLC.A10 parental alleles of the TN-DH population in the upstream region and in intron 1. Expression of both BnFLC.A10 alleles decreased during vernalization, but decreased more slowly in the winter parent Tapidor. Haplotyping and association analysis showed that one of the polymorphic sites upstream of BnFLC.A10 is strongly associated with the vernalization requirement of rapeseed (r2 = 0.93, χ2 = 0.50). This polymorphic site is derived from a Tourist-like miniature inverted-repeat transposable element (MITE) insertion/deletion in the upstream region of BnFLC.A10. The MITE sequence was not present in the BnFLC.A10 gene in spring-type rapeseed, nor in ancestral 'A' genome species B. rapa genotypes. Our results suggest that the insertion may have occurred in winter rapeseed after B. napus speciation. Our findings strongly suggest that (i) BnFLC.A10 is the gene underlying qFT10-4, the QTL for phenotypic diversity of flowering time in the TN-DH population, (ii) the allelic diversity caused by MITE insertion/deletion upstream of BnFLC.A10 is one of the major causes of differentiation of winter and spring genotypes in rapeseed and (iii) winter rapeseed has evolved from spring genotypes through selection pressure at the BnFLC.A10 locus, enabling expanded cultivation of rapeseed along the route of Brassica domestication.

Comparative mapping of quantitative trait loci associated with waterlogging tolerance in barley (Hordeum vulgare L.).

PubMed

Li, Haobing; Vaillancourt, René; Mendham, Neville; Zhou, Meixue

2008-08-27

Resistance to soil waterlogging stress is an important plant breeding objective in high rainfall or poorly drained areas across many countries in the world. The present study was conducted to identify quantitative trait loci (QTLs) associated with waterlogging tolerance (e.g. leaf chlorosis, plant survival and biomass reduction) in barley and compare the QTLs identified across two seasons and in two different populations using a composite map constructed with SSRs, RFLP and Diversity Array Technology (DArT) markers. Twenty QTLs for waterlogging tolerance related traits were found in the two barley double haploid (DH) populations. Several of these QTLs were validated through replication of experiments across seasons or by co-location across populations. Some of these QTLs affected multiple waterlogging tolerance related traits, for example, QTL Qwt4-1 contributed not only to reducing barley leaf chlorosis, but also increasing plant biomass under waterlogging stress, whereas other QTLs controlled both leaf chlorosis and plant survival. Improving waterlogging tolerance in barley is still at an early stage compared with other traits. QTLs identified in this study have made it possible to use marker assisted selection (MAS) in combination with traditional field selection to significantly enhance barley breeding for waterlogging tolerance. There may be some degree of homoeologous relationship between QTLs controlling barley waterlogging tolerance and that in other crops as discussed in this study.

Development of genic cleavage markers in association with seed glucosinolate content in canola.

PubMed

Fu, Ying; Lu, Kun; Qian, Lunwen; Mei, Jiaqin; Wei, Dayong; Peng, Xuhui; Xu, Xinfu; Li, Jiana; Frauen, Martin; Dreyer, Felix; Snowdon, Rod J; Qian, Wei

2015-06-01

The orthologues of Arabidopsis involved in seed glucosinolates metabolism within QTL confidence intervals were identified, and functional markers were developed to facilitate breeding for ultra-low glucosinolates in canola. Further reducing the content of seed glucosinolates will have a positive impact on the seed quality of canola (Brassica napus). In this study 43 quantitative trait loci (QTL) for seed glucosinolate (GSL) content in a low-GSL genetic background were mapped over seven environments in Germany and China in a doubled haploid population from a cross between two low-GSL oilseed rape parents with transgressive segregation. By anchoring these QTL to the reference genomes of B. rapa and B. oleracea, we identified 23 orthologues of Arabidopsis involved in GSL metabolism within the QTL confidence intervals. Sequence polymorphisms between the corresponding coding regions of the parental lines were used to develop cleaved amplified polymorphic site markers for two QTL-linked genes, ISOPROPYLMALATE DEHYDROGENASE1 and ADENOSINE 5'-PHOSPHOSULFATE REDUCTASE 3. The genic cleavage markers were mapped in the DH population into the corresponding intervals of QTL explaining 3.36-6.88 and 4.55-8.67 % of the phenotypic variation for seed GSL, respectively. The markers will facilitate breeding for ultra-low seed GSL content in canola.

Evolution and maintenance of haploid-diploid life cycles in natural populations: The case of the marine brown alga Ectocarpus.

PubMed

Couceiro, Lucía; Le Gac, Mickael; Hunsperger, Heather M; Mauger, Stéphane; Destombe, Christophe; Cock, J Mark; Ahmed, Sophia; Coelho, Susana M; Valero, Myriam; Peters, Akira F

2015-07-01

The evolutionary stability of haploid-diploid life cycles is still controversial. Mathematical models indicate that niche differences between ploidy phases may be a necessary condition for the evolution and maintenance of these life cycles. Nevertheless, experimental support for this prediction remains elusive. In the present work, we explored this hypothesis in natural populations of the brown alga Ectocarpus. Consistent with the life cycle described in culture, Ectocarpus crouaniorum in NW France and E. siliculosus in SW Italy exhibited an alternation between haploid gametophytes and diploid sporophytes. Our field data invalidated, however, the long-standing view of an isomorphic alternation of generations. Gametophytes and sporophytes displayed marked differences in size and, conforming to theoretical predictions, occupied different spatiotemporal niches. Gametophytes were found almost exclusively on the alga Scytosiphon lomentaria during spring whereas sporophytes were present year-round on abiotic substrata. Paradoxically, E. siliculosus in NW France exhibited similar habitat usage despite the absence of alternation of ploidy phases. Diploid sporophytes grew both epilithically and epiphytically, and this mainly asexual population gained the same ecological advantage postulated for haploid-diploid populations. Consequently, an ecological interpretation of the niche differences between haploid and diploid individuals does not seem to satisfactorily explain the evolution of the Ectocarpus life cycle. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Genetic analysis of predicted fatty acid profiles of milk from Danish Holstein and Danish Jersey cattle populations.

PubMed

Hein, L; Sørensen, L P; Kargo, M; Buitenhuis, A J

2018-03-01

The objective of this study was to assess the genetic variability of the detailed fatty acid (FA) profiles of Danish Holstein (DH) and Danish Jersey (DJ) cattle populations. We estimated genetic parameters for 11 FA or groups of FA in milk samples from the Danish milk control system between May 2015 and October 2016. Concentrations of different FA and FA groups in milk samples were measured by mid-infrared spectroscopy. Data used for parameter estimation were from 132,732 first-parity DH cows and 21,966 first-parity DJ cows. We found the highest heritabilities for test day measurements in both populations for short-chain FA (DH = 0.16; DJ = 0.16) and C16:0 (DH = 0.14; DJ = 0.16). In DH, the highest heritabilities were also found for saturated FA and monounsaturated FA (both populations: 0.15). Genetic correlations between the fatty acid traits showed large differences between DH and DJ for especially short-chain FA with the other FA traits measured. Furthermore, genetic correlations of total fat with monounsaturated FA, polyunsaturated FA, short-chain FA, and C16:0 differed markedly between DH and DJ populations. In conclusion, we found genetic variation in the mid-infrared spectroscopy-predicted FA and FA groups of the DH and DJ cattle populations. This finding opens the possibility of using genetic selection to change the FA profiles of dairy cattle. The Authors. Published by FASS Inc. and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Quantitative and qualitative stem rust resistance factors in barley are associated with transcriptional suppression of defense regulons.

PubMed

Moscou, Matthew J; Lauter, Nick; Steffenson, Brian; Wise, Roger P

2011-07-01

Stem rust (Puccinia graminis f. sp. tritici; Pgt) is a devastating fungal disease of wheat and barley. Pgt race TTKSK (isolate Ug99) is a serious threat to these Triticeae grain crops because resistance is rare. In barley, the complex Rpg-TTKSK locus on chromosome 5H is presently the only known source of qualitative resistance to this aggressive Pgt race. Segregation for resistance observed on seedlings of the Q21861 × SM89010 (QSM) doubled-haploid (DH) population was found to be predominantly qualitative, with little of the remaining variance explained by loci other than Rpg-TTKSK. In contrast, analysis of adult QSM DH plants infected by field inoculum of Pgt race TTKSK in Njoro, Kenya, revealed several additional quantitative trait loci that contribute to resistance. To molecularly characterize these loci, Barley1 GeneChips were used to measure the expression of 22,792 genes in the QSM population after inoculation with Pgt race TTKSK or mock-inoculation. Comparison of expression Quantitative Trait Loci (eQTL) between treatments revealed an inoculation-dependent expression polymorphism implicating Actin depolymerizing factor3 (within the Rpg-TTKSK locus) as a candidate susceptibility gene. In parallel, we identified a chromosome 2H trans-eQTL hotspot that co-segregates with an enhancer of Rpg-TTKSK-mediated, adult plant resistance discovered through the Njoro field trials. Our genome-wide eQTL studies demonstrate that transcript accumulation of 25% of barley genes is altered following challenge by Pgt race TTKSK, but that few of these genes are regulated by the qualitative Rpg-TTKSK on chromosome 5H. It is instead the chromosome 2H trans-eQTL hotspot that orchestrates the largest inoculation-specific responses, where enhanced resistance is associated with transcriptional suppression of hundreds of genes scattered throughout the genome. Hence, the present study associates the early suppression of genes expressed in this host-pathogen interaction with enhancement of R-gene mediated resistance.

Quantitative and Qualitative Stem Rust Resistance Factors in Barley Are Associated with Transcriptional Suppression of Defense Regulons

PubMed Central

Moscou, Matthew J.; Lauter, Nick; Steffenson, Brian; Wise, Roger P.

2011-01-01

Stem rust (Puccinia graminis f. sp. tritici; Pgt) is a devastating fungal disease of wheat and barley. Pgt race TTKSK (isolate Ug99) is a serious threat to these Triticeae grain crops because resistance is rare. In barley, the complex Rpg-TTKSK locus on chromosome 5H is presently the only known source of qualitative resistance to this aggressive Pgt race. Segregation for resistance observed on seedlings of the Q21861 × SM89010 (QSM) doubled-haploid (DH) population was found to be predominantly qualitative, with little of the remaining variance explained by loci other than Rpg-TTKSK. In contrast, analysis of adult QSM DH plants infected by field inoculum of Pgt race TTKSK in Njoro, Kenya, revealed several additional quantitative trait loci that contribute to resistance. To molecularly characterize these loci, Barley1 GeneChips were used to measure the expression of 22,792 genes in the QSM population after inoculation with Pgt race TTKSK or mock-inoculation. Comparison of expression Quantitative Trait Loci (eQTL) between treatments revealed an inoculation-dependent expression polymorphism implicating Actin depolymerizing factor3 (within the Rpg-TTKSK locus) as a candidate susceptibility gene. In parallel, we identified a chromosome 2H trans-eQTL hotspot that co-segregates with an enhancer of Rpg-TTKSK-mediated, adult plant resistance discovered through the Njoro field trials. Our genome-wide eQTL studies demonstrate that transcript accumulation of 25% of barley genes is altered following challenge by Pgt race TTKSK, but that few of these genes are regulated by the qualitative Rpg-TTKSK on chromosome 5H. It is instead the chromosome 2H trans-eQTL hotspot that orchestrates the largest inoculation-specific responses, where enhanced resistance is associated with transcriptional suppression of hundreds of genes scattered throughout the genome. Hence, the present study associates the early suppression of genes expressed in this host–pathogen interaction with enhancement of R-gene mediated resistance. PMID:21829384

Genetic mapping of a new race specific resistance allele effective to Puccinia hordei at the Rph9/Rph12 locus on chromosome 5HL in barley.

PubMed

Dracatos, Peter M; Khatkar, Mehar S; Singh, Davinder; Park, Robert F

2014-12-20

Barley is an important cereal crop cultivated for malt and ruminant feed and in certain regions it is used for human consumption. It is vulnerable to numerous foliar diseases including barley leaf rust caused by the pathogen Puccinia hordei. A temporarily designated resistance locus RphCantala (RphC) identified in the Australian Hordeum vulgare L. cultivar 'Cantala' displayed an intermediate to low infection type (";12 = N") against the P. hordei pathotype 253P- (virulent on Rph1, Rph2, Rph4, Rph6, Rph8 and RphQ). Phenotypic assessment of a 'CI 9214' (susceptible) x 'Stirling' (RphC) (CI 9214/Stirling) doubled haploid (DH) population at the seedling stage using P. hordei pathotype 253P-, confirmed that RphC was monogenically inherited. Marker-trait association analysis of RphC in the CI 9214/Stirling DH population using 4,500 DArT-seq markers identified a highly significant (-log10Pvalue > 17) single peak on the long arm of chromosome 5H (5HL). Further tests of allelism determined that RphC was genetically independent of Rph3, Rph7, Rph11, Rph13 and Rph14, and was an allele of Rph12 (Rph9.z), which also maps to 5HL. Multipathotype tests and subsequent pedigree analysis determined that 14 related Australian barley varieties (including 'Stirling' and 'Cantala') carry RphC and that the likely source of this resistance is via a Czechoslovakian landrace LV-Kvasice-NA-Morave transferred through common ancestral cultivars 'Hanna' and 'Abed Binder'. RphC is an allele of Rph12 (Rph9.z) and is therefore designated Rph9.am. Bioinformatic analysis using sequence arrays from DArT-seq markers in linkage disequilibrium with Rph9.am identified possible candidates for further gene cloning efforts and marker development at the Rph9/Rph12/Rph9.am locus.

Characterization of the quantitative trait locus OilA1 for oil content in Brassica napus.

PubMed

Chen, Yubo; Qi, Lu; Zhang, Xiaoyu; Huang, Jixiang; Wang, Jibian; Chen, Hongcheng; Ni, Xiyuan; Xu, Fei; Dong, Yanjun; Xu, Haiming; Zhao, Jianyi

2013-10-01

Increasing seed oil content has become one of the most important breeding criteria in rapeseed (Brassica napus). However, oil content is a complex quantitative trait. QTL mapping in a double haploid population (SG population) emerging from a cross between a German (Sollux) and Chinese (Gaoyou) cultivars revealed one QTL for oil content on linkage group A1 (OilA1), which was mapped to a 17 cM genetic interval. To further validate and characterize the OilA1, we constructed a high-resolution map using B. rapa sequence resources and developed a set of near-isogenic lines (NILs) by employing a DH line SG-DH267 as donor and Chinese parent Gaoyou as recurrent background. The results showed highly conserved synteny order between B. rapa and B. napus within the linkage group A1 and revealed a possible centromere region between two markers ZAASA1-38 and NTP3 (2.5 cM). OilA1 was firstly validated by 250 BC5F2 plants and was confirmed in a 10.6 cM interval between the markers ZAASA1-47 and ZAASA1-77. Further substitution mapping was conducted by using two generations of QTL-NILs, 283 lines from eight BC5F3:4 families and 428 plants from six BC5F4 sub-NILs and thus narrowed the OilA1 interval to 6.9 cM and 4.3 cM (1.4 Mb), respectively. Field investigations with two replications using homozygous BC5F3:4 sister sub-NILs indicated that NILs, which carry a Sollux chromosome segment across the target region showed significant higher oil content (1.26 %, p < 0.001) than their sister NILs containing Gaoyou chromosome. The OilA1 locus is of particular interest for breeding purpose in China because 80 % of Chinese cultivars do not carry this desirable allele.

Investigation of the prevalence, clinical features, and risk factors of dentin hypersensitivity in a selected Brazilian population.

PubMed

Scaramucci, Taís; de Almeida Anfe, Taciana Emília; da Silva Ferreira, Stella; Frias, Antônio Carlos; Sobral, Maria Angela Pita

2014-01-01

To evaluate the prevalence, clinical features, and risk factors of dentin hypersensitivity (DH) in a Brazilian population. 300 patients at the Dentistry Clinic of the University of São Paulo participated in this study. The subjects completed a questionnaire regarding their personal information, the presence of DH, and some of its risk factors. Following completion of the questionnaire, a clinical examination was undertaken. To confirm the presence of DH, the subjects were evaluated with the use of a probe and cold air from a triple syringe. Statistical analysis was performed with the chi-square test and odds ratio, with the critical level p <0.05. The prevalence of DH was 46%. Females presented a higher prevalence than males (p <0.05). The left posterior region was affected by DH the most (maxilla = 41% and mandible = 36%). Cold was reported as the most common pain-inducing stimulus (88%). The pain was described as "discomfort" by 51% of the subjects with DH. Toothbrushing four times a day (p <0.05), toothbrushing with excessive force (p <0.05), bruxism (p <0.05), and gastroesophageal reflux (p <0.05) were strongly correlated with DH. The prevalence of DH was particularly high. The risk factors for DH were gender (female), toothbrushing four times a day, toothbrushing with excessive force, bruxism, and gastroesophageal reflux. DH was a common finding in this population suggesting that preventive measures considering its risk factors must be implemented in order to reduce or control the symptoms.

Interploidal hybridization and mating patterns in the Sphagnum subsecundum complex.

PubMed

Ricca, M; Szövényi, P; Temsch, E M; Johnson, M G; Shaw, A J

2011-08-01

Polyploidization is thought to result in instant sympatric speciation, but several cases of hybrid zones between one of the parental species and its polyploid derivative have been documented. Previous work showed that diploid Sphagnum lescurii is an allopolyploid derived from the haploids S. lescurii (maternal progenitor) and S. subsecundum (paternal progenitor). Here, we report the results from analyses of a population where allodiploid and haploid S. lescurii co-occur and produce sporophytes. We tested (i) whether haploids and diploids form hybrid triploid sporophytes; (ii) how hybrid and nonhybrid sporophytes compare in fitness; (iii) whether hybrid sporophytes form viable spores; (iv) the ploidy of any viable gametophyte offspring from hybrid sporophytes; (v) the relative viability of sporelings derived from hybrid and nonhybrid sporophytes; and (vi) if interploidal hybridization results in introgression between the allopolyploid and its haploid progenitor. We found that triploid hybrid sporophytes do occur and are larger than nonhybrid sporophytes, but exhibit very low germination percentages and produce sporelings that develop more slowly than those from nonhybrid sporophytes. All sporophytes attached to haploid gametophytes were triploid and were sired by diploid males, but all sporophytes attached to diploid gametophytes were tetraploid. This asymmetric pattern of interploidal hybridization is related to an absence of haploid male gametophytes in the population. Surprisingly, all sporelings from triploid sporophytes were triploid, yet were genetically variable, suggesting some form of aberrant meiosis that warrants further study. There was limited (but some) evidence of introgression between allodiploid and haploid S. lescurii. © 2011 Blackwell Publishing Ltd.

High-density genetic mapping of a major QTL for resistance to multiple races of loose smut in a tetraploid wheat cross

PubMed Central

Kumar, Sachin; Knox, Ron E.; Singh, Asheesh K.; DePauw, Ron M.; Campbell, Heather L.; Isidro-Sanchez, Julio; Clarke, Fran R.; Pozniak, Curtis J.; N’Daye, Amidou; Meyer, Brad; Sharpe, Andrew; Ruan, Yuefeng; Cuthbert, Richard D.; Somers, Daryl; Fedak, George

2018-01-01

Loose smut, caused by Ustilago tritici (Pers.) Rostr., is a systemic disease of tetraploid durum wheat (Triticum turgidum L.). Loose smut can be economically controlled by growing resistant varieties, making it important to find and deploy new sources of resistance. Blackbird, a variety of T. turgidum L. subsp. carthlicum (Nevski) A. Love & D. Love, carries a high level of resistance to loose smut. Blackbird was crossed with the loose smut susceptible durum cultivar Strongfield to produce a doubled haploid (DH) mapping population. The parents and progenies were inoculated with U. tritici races T26, T32 and T33 individually and as a mixture at Swift Current, Canada in 2011 and 2012 and loose smut incidence (LSI) was assessed. Genotyping of the DH population and parents using an Infinium iSelect 90K single nucleotide polymorphism (SNP) array identified 12,952 polymorphic SNPs. The SNPs and 426 SSRs (previously genotyped in the same population) were mapped to 16 linkage groups spanning 3008.4 cM at an average inter-marker space of 0.2 cM in a high-density genetic map. Composite interval mapping analysis revealed three significant quantitative trait loci (QTL) for loose smut resistance on chromosomes 3A, 6B and 7A. The loose smut resistance QTL on 6B (QUt.spa-6B.2) and 7A (QUt.spa-7A.2) were derived from Blackbird. Strongfield contributed the minor QTL on 3A (QUt.spa-3A.2). The resistance on 6B was a stable major QTL effective against all individual races and the mixture of the three races; it explained up to 74% of the phenotypic variation. This study is the first attempt in durum wheat to identify and map loose smut resistance QTL using a high-density genetic map. The QTL QUt.spa-6B.2 would be an effective source for breeding resistance to multiple races of the loose smut pathogen because it provides near-complete broad resistance to the predominant virulence on the Canadian prairies. PMID:29485999

High Density Linkage Map Construction and QTL Detection for Three Silique-Related Traits in Orychophragmus violaceus Derived Brassica napus Population.

PubMed

Yang, Yi; Shen, Yusen; Li, Shunda; Ge, Xianhong; Li, Zaiyun

2017-01-01

Seeds per silique (SS), seed weight (SW), and silique length (SL) are important determinant traits of seed yield potential in rapeseed ( Brassica napus L.), and are controlled by naturally occurring quantitative trait loci (QTLs). Mapping QTLs to narrow chromosomal regions provides an effective means of characterizing the genetic basis of these complex traits. Orychophragmus violaceus is a crucifer with long siliques, many SS, and heavy seeds. A novel B. napus introgression line with many SS was previously selected from multiple crosses ( B. rapa ssp. chinesis × O. violaceus ) × B. napus . In present study, a doubled haploid (DH) population with 167 lines was established from a cross between the introgression line and a line with far fewer SS, in order to detect QTLs for silique-related traits. By screening with a Brassica 60K single nucleotide polymorphism (SNP) array, a high-density linkage map consisting of 1,153 bins and spanning a cumulative length of 2,209.1 cM was constructed, using 12,602 high-quality polymorphic SNPs in the DH population. The average recombination bin densities of the A and C subgenomes were 1.7 and 2.4 cM, respectively. 45 QTLs were identified for the three traits in all, which explained 4.0-34.4% of the total phenotypic variation; 20 of them were integrated into three unique QTLs by meta-analysis. These unique QTLs revealed a significant positive correlation between SS and SL and a significant negative correlation between SW and SS, and were mapped onto the linkage groups A05, C08, and C09. A trait-by-trait meta-analysis revealed eight, four, and seven consensus QTLs for SS, SW, and SL, respectively, and five major QTLs ( cqSS.A09b, cqSS.C09, cqSW.A05, cqSW.C09 , and cqSL.C09 ) were identified. Five, three, and four QTLs for SS, SW, and SL, respectively, might be novel QTLs because of the existence of alien genetic loci for these traits in the alien introgression. Thirty-eight candidate genes underlying nine QTLs for silique-related traits were identified.

Integration of data from a safety net health care system into the Vaccine Safety Datalink.

PubMed

Hambidge, Simon J; Ross, Colleen; Shoup, Jo Ann; Wain, Kris; Narwaney, Komal; Breslin, Kristin; Weintraub, Eric S; McNeil, Michael M

2017-03-01

In 2013 the Institute of Medicine suggested that the Vaccine Safety DataLink (VSD) should broaden its population by including data of more patients from low income and racially and ethnically diverse backgrounds. In response, Kaiser Permanente Colorado (KPCO) partnered with Denver Health (DH), an integrated safety net health care system, to explore the integration of DH data. We compared three different methods (reference date of September 1, 2013): "Empanelment" (any patient who has had a primary care visit in the past 18months), "Proxy-enrollment" (two health care visits in 3years separated by 90days), and "Enrollment" in a managed care plan. For each of these methods, we compared cohort size, vaccination rates, socio-demographic characteristics, and health care utilization. The empaneled population at DH provided the best comparison to KPCO. DH's empaneled population was 111,330 (57,173 adults; 54,157 children), while KPCO had 436,290 empaneled patients (336,462 adults; 99,828 children). Vaccination rates in both health care systems for empaneled patients were comparable. Two year-old up-to-date coverage rates were 83.2% (KPCO) and 86.9% (DH); rates for adolescent Tdap and MCV4 were 85.5% (KPCO) and 90.6% (DH). There were significant differences in the two populations in age, gender, race, preferred language, and % Federal Poverty Level (FPL) (DH 70.7%<100% FPL; KPCO 17.4%), as well as in healthcare utilization - for example pediatric emergency department utilization was twice as high at DH. Using a cohort of "empaneled" patients, it is possible to integrate data from a safety net health care system that does not have a uniform managed care population into the VSD, and to compare vaccination rates, socio-demographic characteristics, and health care utilization across the two systems. The KPCO-DH collaboration may serve as a model for incorporating data from a safety net healthcare system into the VSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Annotation of differentially expressed genes in the somatic embryogenesis of musa and their location in the banana genome.

PubMed

Maldonado-Borges, Josefina Ines; Ku-Cauich, José Roberto; Escobedo-Graciamedrano, Rosa Maria

2013-01-01

Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somatic embryogenesis of Musa acuminata Colla ssp. malaccensis, and a comparison was made between their differential transcribed fragments (TDFs) and the sequenced genome of the double haploid- (DH-) Pahang of the malaccensis subspecies that is available in the network. A total of 253 transcript-derived fragments (TDFs) were detected with apparent size of 100-4000 bp using 5 pairs of AFLP primers, of which 21 were differentially expressed during the different stages of banana embryogenesis; 15 of the sequences have matched DH-Pahang chromosomes, with 7 of them being homologous to gene sequences encoding either known or putative protein domains of higher plants. Four TDF sequences were located in all Musa chromosomes, while the rest were located in one or two chromosomes. Their putative individual function is briefly reviewed based on published information, and the potential roles of these genes in embryo development are discussed. Thus the availability of the genome of Musa and the information of TDFs sequences presented here opens new possibilities for an in-depth study of the molecular and biochemical research of zygotic and somatic embryogenesis of Musa.

Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort

PubMed Central

Marks, Rose A.; Burton, James F.; McLetchie, D. Nicholas

2016-01-01

Background and Aims Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. Methods To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. Key Results We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. Conclusions By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. PMID:27325895

A Major Locus for Manganese Tolerance Maps on Chromosome A09 in a Doubled Haploid Population of Brassica napus L.

PubMed

Raman, Harsh; Raman, Rosy; McVittie, Brett; Orchard, Beverley; Qiu, Yu; Delourme, Regine

2017-01-01

Soil acidity poses a major threat to productivity of several crops; mainly due to the prevalence of toxic levels of Al 3+ and Mn 2+ . Crop productivity could be harnessed on acid soils via the development of plant varieties tolerant to phytotoxic levels of these cations. In this study, we investigated the extent of natural variation for Mn 2+ tolerance among ten parental lines of the Australian and International canola mapping populations. Response to Mn 2+ toxicity was measured on the bases of cotyledon chlorosis, shoot biomass, and leaf area in nutrient solution under control (9 μM of MnCl 2 ⋅4H 2 O) and Mn treatment (125 μM of MnCl 2 ⋅4H 2 O). Among parental lines, we selected Darmor- bzh and Yudal that showed significant and contrasting variation in Mn 2+ tolerance to understand genetic control and identify the quantitative trait loci (QTL) underlying Mn 2+ tolerance. We evaluated parental lines and their doubled haploid (DH) progenies (196 lines) derived from an F 1 cross, Darmor- bzh /Yudal for Mn 2+ tolerance. Mn 2+ -tolerant genotypes had significantly higher shoot biomass and leaf area compared to Mn 2+ -sensitive genotypes. A genetic linkage map based on 7,805 DArTseq markers corresponding to 2,094 unique loci was constructed and further utilized for QTL identification. A major locus, BnMn 2+ . A09 was further mapped with a SNP marker, Bn-A09-p29012402 (LOD score of 34.6) accounting for most of the variation in Mn 2+ tolerance on chromosome A09. This is the first report on the genomic localization of a Mn 2+ tolerance locus in B. napus . Additionally, an ortholog of A. thaliana encoding for cation efflux facilitator transporter was located within 3,991 bp from significant SNP marker associated with BnMn 2+ . A09 . A suite of genome sequence based markers (DArTseq and Illumina Infinium SNPs) flanking the BnMn 2+ . A09 locus would provide an invaluable tool for various molecular breeding applications to improve canola production and profitability on Mn 2+ toxic soils.

A Major Locus for Manganese Tolerance Maps on Chromosome A09 in a Doubled Haploid Population of Brassica napus L.

PubMed Central

Raman, Harsh; Raman, Rosy; McVittie, Brett; Orchard, Beverley; Qiu, Yu; Delourme, Regine

2017-01-01

Soil acidity poses a major threat to productivity of several crops; mainly due to the prevalence of toxic levels of Al3+ and Mn2+. Crop productivity could be harnessed on acid soils via the development of plant varieties tolerant to phytotoxic levels of these cations. In this study, we investigated the extent of natural variation for Mn2+ tolerance among ten parental lines of the Australian and International canola mapping populations. Response to Mn2+ toxicity was measured on the bases of cotyledon chlorosis, shoot biomass, and leaf area in nutrient solution under control (9 μM of MnCl2⋅4H2O) and Mn treatment (125 μM of MnCl2⋅4H2O). Among parental lines, we selected Darmor-bzh and Yudal that showed significant and contrasting variation in Mn2+ tolerance to understand genetic control and identify the quantitative trait loci (QTL) underlying Mn2+ tolerance. We evaluated parental lines and their doubled haploid (DH) progenies (196 lines) derived from an F1 cross, Darmor-bzh/Yudal for Mn2+ tolerance. Mn2+-tolerant genotypes had significantly higher shoot biomass and leaf area compared to Mn2+-sensitive genotypes. A genetic linkage map based on 7,805 DArTseq markers corresponding to 2,094 unique loci was constructed and further utilized for QTL identification. A major locus, BnMn2+.A09 was further mapped with a SNP marker, Bn-A09-p29012402 (LOD score of 34.6) accounting for most of the variation in Mn2+ tolerance on chromosome A09. This is the first report on the genomic localization of a Mn2+ tolerance locus in B. napus. Additionally, an ortholog of A. thaliana encoding for cation efflux facilitator transporter was located within 3,991 bp from significant SNP marker associated with BnMn2+.A09. A suite of genome sequence based markers (DArTseq and Illumina Infinium SNPs) flanking the BnMn2+.A09 locus would provide an invaluable tool for various molecular breeding applications to improve canola production and profitability on Mn2+ toxic soils. PMID:29312361

Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort.

PubMed

Marks, Rose A; Burton, James F; McLetchie, D Nicholas

2016-08-01

Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

QTL and QTL x environment effects on agronomic and nitrogen acquisition traits in rice.

PubMed

Senthilvel, Senapathy; Vinod, Kunnummal Kurungara; Malarvizhi, Palaniappan; Maheswaran, Marappa

2008-09-01

Agricultural environments deteriorate due to excess nitrogen application. Breeding for low nitrogen responsive genotypes can reduce soil nitrogen input. Rice genotypes respond variably to soil available nitrogen. The present study attempted quantification of genotype x nitrogen level interaction and mapping of quantitative trait loci (QTLs) associated with nitrogen use efficiency (NUE) and other associated agronomic traits. Twelve parameters were observed across a set of 82 double haploid (DH) lines derived from IR64/Azucena. Three nitrogen regimes namely, native (0 kg/ha; no nitrogen applied), optimum (100 kg/ha) and high (200 kg/ha) replicated thrice were the environments. The parents and DH lines were significantly varying for all traits under different nitrogen regimes. All traits except plant height recorded significant genotype x environment interaction. Individual plant yield was positively correlated with nitrogen use efficiency and nitrogen uptake. Sixteen QTLs were detected by composite interval mapping. Eleven QTLs showed significant QTL x environment interactions. On chromosome 3, seven QTLs were detected associated with nitrogen use, plant yield and associated traits. A QTL region between markers RZ678, RZ574 and RZ284 was associated with nitrogen use and yield. This chromosomal region was enriched with expressed gene sequences of known key nitrogen assimilation genes.

Annotation of Differentially Expressed Genes in the Somatic Embryogenesis of Musa and Their Location in the Banana Genome

PubMed Central

Maldonado-Borges, Josefina Ines; Ku-Cauich, José Roberto; Escobedo-GraciaMedrano, Rosa Maria

2013-01-01

Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somatic embryogenesis of Musa acuminata Colla ssp. malaccensis, and a comparison was made between their differential transcribed fragments (TDFs) and the sequenced genome of the double haploid- (DH-) Pahang of the malaccensis subspecies that is available in the network. A total of 253 transcript-derived fragments (TDFs) were detected with apparent size of 100–4000 bp using 5 pairs of AFLP primers, of which 21 were differentially expressed during the different stages of banana embryogenesis; 15 of the sequences have matched DH-Pahang chromosomes, with 7 of them being homologous to gene sequences encoding either known or putative protein domains of higher plants. Four TDF sequences were located in all Musa chromosomes, while the rest were located in one or two chromosomes. Their putative individual function is briefly reviewed based on published information, and the potential roles of these genes in embryo development are discussed. Thus the availability of the genome of Musa and the information of TDFs sequences presented here opens new possibilities for an in-depth study of the molecular and biochemical research of zygotic and somatic embryogenesis of Musa. PMID:24027442

O father where art thou? Paternity analyses in a natural population of the haploid-diploid seaweed Chondrus crispus.

PubMed

Krueger-Hadfield, S A; Roze, D; Correa, J A; Destombe, C; Valero, M

2015-02-01

The link between life history traits and mating systems in diploid organisms has been extensively addressed in the literature, whereas the degree of selfing and/or inbreeding in natural populations of haploid-diploid organisms, in which haploid gametophytes alternate with diploid sporophytes, has been rarely measured. Dioecy has often been used as a proxy for the mating system in these organisms. Yet, dioecy does not prevent the fusion of gametes from male and female gametophytes originating from the same sporophyte. This is likely a common occurrence when spores from the same parent are dispersed in clumps and recruit together. This pattern of clumped spore dispersal has been hypothesized to explain significant heterozygote deficiency in the dioecious haploid-diploid seaweed Chondrus crispus. Fronds and cystocarps (structures in which zygotes are mitotically amplified) were sampled in two 25 m(2) plots located within a high and a low intertidal zone and genotyped at 5 polymorphic microsatellite loci in order to explore the mating system directly using paternity analyses. Multiple males sired cystocarps on each female, but only one of the 423 paternal genotypes corresponded to a field-sampled gametophyte. Nevertheless, larger kinship coefficients were detected between males siring cystocarps on the same female in comparison with males in the entire population, confirming restricted spermatial and clumped spore dispersal. Such dispersal mechanisms may be a mode of reproductive assurance due to nonmotile gametes associated with putatively reduced effects of inbreeding depression because of the free-living haploid stage in C. crispus.

Asexual and sexual replication in sporulating organisms

NASA Astrophysics Data System (ADS)

Lee, Bohyun; Tannenbaum, Emmanuel

2007-08-01

Replication via sporulation is the replication strategy for all multicellular life, and may even be observed in unicellular life (such as with budding yeast). We consider diploid populations replicating via one of two possible sporulation mechanisms. (1) Asexual sporulation, whereby adult organisms produce single-celled diploid spores that grow into adults themselves. (2) Sexual sporulation, whereby adult organisms produce single-celled diploid spores that divide into haploid gametes. The haploid gametes enter a haploid “pool,” where they may recombine with other haploids to form a diploid spore that then grows into an adult. We consider a haploid fusion rate given by second-order reaction kinetics. We work with a simplified model where the diploid genome consists of only two chromosomes, each of which may be rendered defective with a single point mutation of the wild-type. We find that the asexual strategy is favored when the rate of spore production is high compared to the characteristic growth rate from a spore to a reproducing adult. Conversely, the sexual strategy is favored when the rate of spore production is low compared to the characteristic growth rate from a spore to a reproducing adult. As the characteristic growth time increases, or as the population density increases, the critical ratio of spore production rate to organism growth rate at which the asexual strategy overtakes the sexual one is pushed to higher values. Therefore, the results of this model suggest that, for complex multicellular organisms, sexual replication is favored at high population densities and low growth and sporulation rates.

Standing at the Gateway to Europe - The Genetic Structure of Western Balkan Populations Based on Autosomal and Haploid Markers

PubMed Central

Kovacevic, Lejla; Tambets, Kristiina; Ilumäe, Anne-Mai; Kushniarevich, Alena; Yunusbayev, Bayazit; Solnik, Anu; Bego, Tamer; Primorac, Dragan; Skaro, Vedrana; Leskovac, Andreja; Jakovski, Zlatko; Drobnic, Katja; Tolk, Helle-Viivi; Kovacevic, Sandra; Rudan, Pavao; Metspalu, Ene; Marjanovic, Damir

2014-01-01

Contemporary inhabitants of the Balkan Peninsula belong to several ethnic groups of diverse cultural background. In this study, three ethnic groups from Bosnia and Herzegovina - Bosniacs, Bosnian Croats and Bosnian Serbs - as well as the populations of Serbians, Croatians, Macedonians from the former Yugoslav Republic of Macedonia, Montenegrins and Kosovars have been characterized for the genetic variation of 660 000 genome-wide autosomal single nucleotide polymorphisms and for haploid markers. New autosomal data of the 70 individuals together with previously published data of 20 individuals from the populations of the Western Balkan region in a context of 695 samples of global range have been analysed. Comparison of the variation data of autosomal and haploid lineages of the studied Western Balkan populations reveals a concordance of the data in both sets and the genetic uniformity of the studied populations, especially of Western South-Slavic speakers. The genetic variation of Western Balkan populations reveals the continuity between the Middle East and Europe via the Balkan region and supports the scenario that one of the major routes of ancient gene flows and admixture went through the Balkan Peninsula. PMID:25148043

Standing at the gateway to Europe--the genetic structure of Western balkan populations based on autosomal and haploid markers.

PubMed

Kovacevic, Lejla; Tambets, Kristiina; Ilumäe, Anne-Mai; Kushniarevich, Alena; Yunusbayev, Bayazit; Solnik, Anu; Bego, Tamer; Primorac, Dragan; Skaro, Vedrana; Leskovac, Andreja; Jakovski, Zlatko; Drobnic, Katja; Tolk, Helle-Viivi; Kovacevic, Sandra; Rudan, Pavao; Metspalu, Ene; Marjanovic, Damir

2014-01-01

Contemporary inhabitants of the Balkan Peninsula belong to several ethnic groups of diverse cultural background. In this study, three ethnic groups from Bosnia and Herzegovina - Bosniacs, Bosnian Croats and Bosnian Serbs - as well as the populations of Serbians, Croatians, Macedonians from the former Yugoslav Republic of Macedonia, Montenegrins and Kosovars have been characterized for the genetic variation of 660 000 genome-wide autosomal single nucleotide polymorphisms and for haploid markers. New autosomal data of the 70 individuals together with previously published data of 20 individuals from the populations of the Western Balkan region in a context of 695 samples of global range have been analysed. Comparison of the variation data of autosomal and haploid lineages of the studied Western Balkan populations reveals a concordance of the data in both sets and the genetic uniformity of the studied populations, especially of Western South-Slavic speakers. The genetic variation of Western Balkan populations reveals the continuity between the Middle East and Europe via the Balkan region and supports the scenario that one of the major routes of ancient gene flows and admixture went through the Balkan Peninsula.

Semiconservative quasispecies equations for polysomic genomes: The general case

NASA Astrophysics Data System (ADS)

Itan, Eran; Tannenbaum, Emmanuel

2010-06-01

This paper develops a formulation of the quasispecies equations appropriate for polysomic, semiconservatively replicating genomes. This paper is an extension of previous work on the subject, which considered the case of haploid genomes. Here, we develop a more general formulation of the quasispecies equations that is applicable to diploid and even polyploid genomes. Interestingly, with an appropriate classification of population fractions, we obtain a system of equations that is formally identical to the haploid case. As with the work for haploid genomes, we consider both random and immortal DNA strand chromosome segregation mechanisms. However, in contrast to the haploid case, we have found that an analytical solution for the mean fitness is considerably more difficult to obtain for the polyploid case. Accordingly, whereas for the haploid case we obtained expressions for the mean fitness for the case of an analog of the single-fitness-peak landscape for arbitrary lesion repair probabilities (thereby allowing for noncomplementary genomes), here we solve for the mean fitness for the restricted case of perfect lesion repair.

Gametic embryogenesis and haploid technology as valuable support to plant breeding.

PubMed

Germanà, Maria Antonietta

2011-05-01

Plant breeding is focused on continuously increasing crop production to meet the needs of an ever-growing world population, improving food quality to ensure a long and healthy life and address the problems of global warming and environment pollution, together with the challenges of developing novel sources of biofuels. The breeders' search for novel genetic combinations, with which to select plants with improved traits to satisfy both farmers and consumers, is endless. About half of the dramatic increase in crop yield obtained in the second half of the last century has been achieved thanks to the results of genetic improvement, while the residual advance has been due to the enhanced management techniques (pest and disease control, fertilization, and irrigation). Biotechnologies provide powerful tools for plant breeding, and among these ones, tissue culture, particularly haploid and doubled haploid technology, can effectively help to select superior plants. In fact, haploids (Hs), which are plants with gametophytic chromosome number, and doubled haploids (DHs), which are haploids that have undergone chromosome duplication, represent a particularly attractive biotechnological method to accelerate plant breeding. Currently, haploid technology, making possible through gametic embryogenesis the single-step development of complete homozygous lines from heterozygous parents, has already had a huge impact on agricultural systems of many agronomically important crops, representing an integral part in their improvement programmes. The aim of this review was to provide some background, recent advances, and future prospective on the employment of haploid technology through gametic embryogenesis as a powerful tool to support plant breeding.

Epistasis interaction of QTL effects as a genetic parameter influencing estimation of the genetic additive effect.

PubMed

Bocianowski, Jan

2013-03-01

Epistasis, an additive-by-additive interaction between quantitative trait loci, has been defined as a deviation from the sum of independent effects of individual genes. Epistasis between QTLs assayed in populations segregating for an entire genome has been found at a frequency close to that expected by chance alone. Recently, epistatic effects have been considered by many researchers as important for complex traits. In order to understand the genetic control of complex traits, it is necessary to clarify additive-by-additive interactions among genes. Herein we compare estimates of a parameter connected with the additive gene action calculated on the basis of two models: a model excluding epistasis and a model with additive-by-additive interaction effects. In this paper two data sets were analysed: 1) 150 barley doubled haploid lines derived from the Steptoe × Morex cross, and 2) 145 DH lines of barley obtained from the Harrington × TR306 cross. The results showed that in cases when the effect of epistasis was different from zero, the coefficient of determination was larger for the model with epistasis than for the one excluding epistasis. These results indicate that epistatic interaction plays an important role in controlling the expression of complex traits.

Cryptic Fitness Advantage: Diploids Invade Haploid Populations Despite Lacking Any Apparent Advantage as Measured by Standard Fitness Assays

PubMed Central

Gerstein, Aleeza C.; Otto, Sarah P.

2011-01-01

Ploidy varies tremendously within and between species, yet the factors that influence when or why ploidy variants are adaptive remains poorly understood. Our previous work found that diploid individuals repeatedly arose within ten replicate haploid populations of Saccharomyces cerevisiae, and in each case we witnessed diploid takeover within 1800 asexual generations of batch culture evolution in the lab. The character that allowed diploids to rise in frequency within haploid populations remains unknown. Here we present a number of experiments conducted with the goal to determine what this trait (or traits) might have been. Experiments were conducted both by sampling a small number of colonies from the stocks frozen every two weeks (93 generations) during the original experiment, as well through sampling a larger number of colonies at the two time points where polymorphism for ploidy was most prevalent. Surprisingly, none of our fitness component measures (lag phase, growth rate, biomass production) indicated an advantage to diploidy. Similarly, competition assays against a common competitor and direct competition between haploid and diploid colonies isolated from the same time point failed to indicate a diploid advantage. Furthermore, we uncovered a tremendous amount of trait variation among colonies of the same ploidy level. Only late-appearing diploids showed a competitive advantage over haploids, indicating that the fitness advantage that allowed eventual takeover was not diploidy per se but an attribute of a subset of diploid lineages. Nevertheless, the initial rise in diploids to intermediate frequency cannot be explained by any of the fitness measures used; we suggest that the resolution to this mystery is negative frequency-dependent selection, which is ignored in the standard fitness measures used. PMID:22174734

Quantitative trait loci for yield and grain plumpness relative to maturity in three populations of barley (Hordeum vulgare L.) grown in a low rain-fall environment

PubMed Central

Obsa, Bulti Tesso; Eglinton, Jason; Coventry, Stewart; March, Timothy; Guillaume, Maxime; Le, Thanh Phuoc; Hayden, Matthew; Langridge, Peter

2017-01-01

Identifying yield and grain plumpness QTL that are independent of developmental variation or phenology is of paramount importance for developing widely adapted and stable varieties through the application of marker assisted selection. The current study was designed to dissect the genetic basis of yield performance and grain plumpness in southern Australia using three doubled haploid (DH) populations developed from crosses between adapted parents that are similar in maturity and overall plant development. Three interconnected genetic populations, Commander x Fleet (CF), Commander x WI4304 (CW), and Fleet x WI4304 (FW) developed from crossing of Australian elite barley genotypes, were used to map QTL controlling yield and grain plumpness. QTL for grain plumpness and yield were analysed using genetic linkage maps made of genotyping-by-sequencing markers and major phenology genes, and field trials at three drought prone environments for two growing seasons. Seventeen QTL were detected for grain plumpness. Eighteen yield QTL explaining from 1.2% to 25.0% of the phenotypic variation were found across populations and environments. Significant QTL x environment interaction was observed for all grain plumpness and yield QTL, except QPlum.FW-4H.1 and QYld.FW-2H.1. Unlike previous yield QTL studies in barley, none of the major developmental genes, including Ppd-H1, Vrn-H1, Vrn-H2 and Vrn-H3, that drive barley adaption significantly affected grain plumpness and yield here. Twenty-two QTL controlled yield or grain plumpness independently of known maturity QTL or genes. Adjustment for maturity effects through co-variance analysis had no major effect on these yield QTL indicating that they control yield per se. PMID:28542571

Quantitative trait loci for yield and grain plumpness relative to maturity in three populations of barley (Hordeum vulgare L.) grown in a low rain-fall environment.

PubMed

Obsa, Bulti Tesso; Eglinton, Jason; Coventry, Stewart; March, Timothy; Guillaume, Maxime; Le, Thanh Phuoc; Hayden, Matthew; Langridge, Peter; Fleury, Delphine

2017-01-01

Identifying yield and grain plumpness QTL that are independent of developmental variation or phenology is of paramount importance for developing widely adapted and stable varieties through the application of marker assisted selection. The current study was designed to dissect the genetic basis of yield performance and grain plumpness in southern Australia using three doubled haploid (DH) populations developed from crosses between adapted parents that are similar in maturity and overall plant development. Three interconnected genetic populations, Commander x Fleet (CF), Commander x WI4304 (CW), and Fleet x WI4304 (FW) developed from crossing of Australian elite barley genotypes, were used to map QTL controlling yield and grain plumpness. QTL for grain plumpness and yield were analysed using genetic linkage maps made of genotyping-by-sequencing markers and major phenology genes, and field trials at three drought prone environments for two growing seasons. Seventeen QTL were detected for grain plumpness. Eighteen yield QTL explaining from 1.2% to 25.0% of the phenotypic variation were found across populations and environments. Significant QTL x environment interaction was observed for all grain plumpness and yield QTL, except QPlum.FW-4H.1 and QYld.FW-2H.1. Unlike previous yield QTL studies in barley, none of the major developmental genes, including Ppd-H1, Vrn-H1, Vrn-H2 and Vrn-H3, that drive barley adaption significantly affected grain plumpness and yield here. Twenty-two QTL controlled yield or grain plumpness independently of known maturity QTL or genes. Adjustment for maturity effects through co-variance analysis had no major effect on these yield QTL indicating that they control yield per se.

Strategies for the Evolution of Sex

NASA Astrophysics Data System (ADS)

Erzan, Ayse

2002-03-01

Using a bit-string model of evolution we find a successful route to diploidy and sex in simple organisms, for a step-like fitness function. Assuming that an excess of deleterious mutations triggers the conversion of haploids to diploidy and sex, we find that only one pair of sexual organisms can take over a finite population, if they engage in sexual reproduction under unfavorable conditions, and otherwise perform mitosis. Then, a haploid-diploid (HD) cycle is established, with an abbreviated haploid phase, as in present day sexual reproduction. If crossover is allowed during meiosis, HD cycles of arbitrary duration can be maintained. We find that the sexual population has a higher mortality rate than asexual diploids, but also a relaxation rate that is an order of magnitude higher. As a result, sexuals have a higher adaptability and lower mutational load on the average, since they can select out the undesirable genes much faster.

Relation Between Near Work and Myopia Progression in Student Population

PubMed Central

Muhamedagic, Lejla; Muhamedagic, Belma; Halilovic, Emina Alimanovic; Halimic, Jasmina Alajbegovic; Stankovic, Aleksa; Muracevic, Bedrana

2014-01-01

Aim To determine relation between near work and myopia progression in student population. Causes of myopia occurrence are not sufficiently explained. Methods This retrospective-prospective, descriptive research included 100 students with verified myopia up to -3 Dsph. Ophthalmological examination and measurement diopter-hours variable (Dh) were done twice, in the period from January 2011 until January 2012. Results A multivariate regression analysis of impact on the difference of distance visual acuity without correction to the right and left eye and difference of automatic computer refractometry in cycloplegia of both eyes indicates that, diopter-hours variable (Dh) had statistically significant impact on increase of distance visual acuity difference (right eye OR: I measurement–Dh 1.489, II measurement–Dh 1.544, p<0.05; left eye OR: I measurement–Dh 1.602, II measurement–Dh 1.538, p<0.05) and automatic computer refractometry in cycloplegia (right eye OR: I measurement 1.361, II measurement 1.493, p<0.05; left eye OR: I measurement 0.931, II measurement 1.019, p<0.05) during both measurements. Conclusion Near work cause the increase of myopia. This research opened a perspective for other researches on the impact of near work on myopia. PMID:24944532

Hyperbaric Oxygen therapy effects on bone regeneration in Type 1 diabetes mellitus in rats.

PubMed

Dias, Pâmella Coelho; Limirio, Pedro Henrique Justino Oliveira; Linhares, Camila Rodrigues Borges; Bergamini, Mariana Lobo; Rocha, Flaviana Soares; Morais, Richarlisson Borges de; Balbi, Ana Paula Coelho; Hiraki, Karen Renata Nakamura; Dechichi, Paula

2018-01-29

The aim of this study was evaluate the effect of HBO on diabetic rats. Twenty rats were distributed into four groups (n = 5): Control (C); Control + HBO (CH); Diabetes (D) and Diabetes + HBO (DH). Diabetes was induced by streptozotocin, and bone defects were created in both femurs in all animals. HBO therapy began immediately after surgery and was performed daily in the CH and DH groups. After 7 days, the animals were euthanized. The femurs were removed, demineralized, embedded in paraffin, and histologic images were analyzed. Qualitative histologic analyses showed more advanced stage bone regeneration in control groups (C and CH) compared with diabetic groups (D and DH). Histomorphometric analysis showed significantly increased bone neoformation in CH compared with the other groups (p < 0.001). Diabetic Group (D) showed decreased bone neoformation compared with non-diabetic groups (C and CH) (p < 0.001); however DH did not differ from C Group (p > 0.05). The mast cell population increased in CH compared with the other groups (C, D, and DH) (p < 0.05). The mast cell population did not differ between D and DH Groups. This study showed that HBO therapy improved early bone regeneration in diabetic rats and increased the mast cell population only in non-diabetic animals. HBO was shown to be important treatment for minimizing deleterious effects of diabetes on bone regeneration.

Exact Markov chains versus diffusion theory for haploid random mating.

PubMed

Tyvand, Peder A; Thorvaldsen, Steinar

2010-05-01

Exact discrete Markov chains are applied to the Wright-Fisher model and the Moran model of haploid random mating. Selection and mutations are neglected. At each discrete value of time t there is a given number n of diploid monoecious organisms. The evolution of the population distribution is given in diffusion variables, to compare the two models of random mating with their common diffusion limit. Only the Moran model converges uniformly to the diffusion limit near the boundary. The Wright-Fisher model allows the population size to change with the generations. Diffusion theory tends to under-predict the loss of genetic information when a population enters a bottleneck. 2010 Elsevier Inc. All rights reserved.

Identification and Expression Analysis of Diapause Hormone and Pheromone Biosynthesis Activating Neuropeptide (DH-PBAN) in the Legume Pod Borer, Maruca vitrata Fabricius

PubMed Central

Chang, Jian-Cheng; Ramasamy, Srinivasan

2014-01-01

Neuropeptides play essential roles in a variety of physiological responses that contribute to the development and reproduction of insects. Both the diapause hormone (DH) and pheromone biosynthesis activating neuropeptide (PBAN) belong to the PBAN/pyrokinin neuropeptide family, which has a conserved pentapeptide motif FXPRL at the C-terminus. We identified the full-length cDNA encoding DH-PBAN in Maruca vitrata, a major lepidopteran pest of leguminous crops. The open reading frame of Marvi-DH-PBAN is 591 bp in length, encoding 197 amino acids, from which five putative neuropeptides [DH, PBAN, α-subesophageal ganglion neuropeptide (SGNP), β-SGNP and γ-SGNP] are derived. Marvi-DH-PBAN was highly similar (83%) to DH-PBAN of Omphisa fuscidentalis (Lepidoptera: Crambidae), but possesses a unique C-terminal FNPRL motif, where asparagine has replaced a serine residue present in other lepidopteran PBAN peptides. The genomic DNA sequence of Marvi-DH-PBAN is 6,231 bp in size and is composed of six exons. Phylogenetic analysis has revealed that the Marvi-DH-PBAN protein sequence is closest to its homolog in Crambidae, but distant from Diptera, Coleoptera and Hymenoptera DH-PBAN, which agrees with the current taxonomy. DH-PBAN transcripts were present in the head and thoracic complex, but absent in the abdomen of M. vitrata. Real-time quantitative PCR assays have demonstrated a relatively higher expression of Marvi-DH-PBAN mRNA in the latter half of the pupal stages and in adults. These findings represent a significant step forward in our understanding of the DH-PBAN gene architecture and phylogeny, and raise the possibility of using Marvi-DH-PBAN to manage M. vitrata populations through molecular techniques. PMID:24409312

Competition between the sperm of a single male can increase the evolutionary rate of haploid expressed genes.

PubMed

Ezawa, Kiyoshi; Innan, Hideki

2013-07-01

The population genetic behavior of mutations in sperm genes is theoretically investigated. We modeled the processes at two levels. One is the standard population genetic process, in which the population allele frequencies change generation by generation, depending on the difference in selective advantages. The other is the sperm competition during each genetic transmission from one generation to the next generation. For the sperm competition process, we formulate the situation where a huge number of sperm with alleles A and B, produced by a single heterozygous male, compete to fertilize a single egg. This "minimal model" demonstrates that a very slight difference in sperm performance amounts to quite a large difference between the alleles' winning probabilities. By incorporating this effect of paternity-sharing sperm competition into the standard population genetic process, we show that fierce sperm competition can enhance the fixation probability of a mutation with a very small phenotypic effect at the single-sperm level, suggesting a contribution of sperm competition to rapid amino acid substitutions in haploid-expressed sperm genes. Considering recent genome-wide demonstrations that a substantial fraction of the mammalian sperm genes are haploid expressed, our model could provide a potential explanation of rapid evolution of sperm genes with a wide variety of functions (as long as they are expressed in the haploid phase). Another advantage of our model is that it is applicable to a wide range of species, irrespective of whether the species is externally fertilizing, polygamous, or monogamous. The theoretical result was applied to mammalian data to estimate the selection intensity on nonsynonymous mutations in sperm genes.

Competition Between the Sperm of a Single Male Can Increase the Evolutionary Rate of Haploid Expressed Genes

PubMed Central

Ezawa, Kiyoshi; Innan, Hideki

2013-01-01

The population genetic behavior of mutations in sperm genes is theoretically investigated. We modeled the processes at two levels. One is the standard population genetic process, in which the population allele frequencies change generation by generation, depending on the difference in selective advantages. The other is the sperm competition during each genetic transmission from one generation to the next generation. For the sperm competition process, we formulate the situation where a huge number of sperm with alleles A and B, produced by a single heterozygous male, compete to fertilize a single egg. This “minimal model” demonstrates that a very slight difference in sperm performance amounts to quite a large difference between the alleles’ winning probabilities. By incorporating this effect of paternity-sharing sperm competition into the standard population genetic process, we show that fierce sperm competition can enhance the fixation probability of a mutation with a very small phenotypic effect at the single-sperm level, suggesting a contribution of sperm competition to rapid amino acid substitutions in haploid-expressed sperm genes. Considering recent genome-wide demonstrations that a substantial fraction of the mammalian sperm genes are haploid expressed, our model could provide a potential explanation of rapid evolution of sperm genes with a wide variety of functions (as long as they are expressed in the haploid phase). Another advantage of our model is that it is applicable to a wide range of species, irrespective of whether the species is externally fertilizing, polygamous, or monogamous. The theoretical result was applied to mammalian data to estimate the selection intensity on nonsynonymous mutations in sperm genes. PMID:23666936

Genetic Population Structure of Dastarcus helophoroides (Coleoptera: Bothrideridae) From Different Long-Horned Beetle Hosts Based on Complete Sequences of Mitochondrial COI.

PubMed

Zhang, Zhengqing; Chang, Yong; Li, Menglou

2017-06-01

Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) is an important natural enemy of long-horned beetles in China, Japan, and Korea. In this study, the genetic sequence of cytochrome oxidase subunit Ι was used to investigate the genetics and relationships within and among D. helophoroides populations collected from five different geographic locations. We used principal component analysis, heatmap, and Venn diagram results to determine the relationship between haplotypes and populations. In total, 26 haplotypes with 51 nucleotide polymorphic sites were defined, and low genetic diversity was found among the different populations. Significant genetic variations were observed mainly within populations, and no correlation was found between genetic distribution and geographical distance. Low pairwise fixation index values (-0.01424 to 0.04896) and high gene flows show that there was high gene exchange between populations. The codistributed haplotype DH01 was suggested to be the most ancestral haplotype, and other haplotypes were thought to have evolved from it through several mutations. In four of the populations, both common haplotypes (DH01, DH03, and DH22) and unique haplotypes were found. Low genetic diversity among different populations is related to a relatively high flight capacity, host movement, and human-aided dispersal of D. helophoroides. The high gene exchange and typically weak population genetic structure among five populations, especially among populations of Anoplophora glabripennis (Motschulsky), Monochamus alternatus (Hope), and Massicus raddei (Blessig), may suggest that these populations cross naturally in the field. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Doubled haploid production from Spanish onion (Allium cepa L.) germplasm: embryogenesis induction, plant regeneration and chromosome doubling.

PubMed

Fayos, Oreto; Vallés, María P; Garcés-Claver, Ana; Mallor, Cristina; Castillo, Ana M

2015-01-01

The use of doubled haploids in onion breeding is limited due to the low gynogenesis efficiency of this species. Gynogenesis capacity from Spanish germplasm, including the sweet cultivar Fuentes de Ebro, the highly pungent landrace BGHZ1354 and the two Valenciana type commercial varieties Recas and Rita, was evaluated and optimized in this study. The OH-1 population, characterized by a high gynogenesis induction, was used as control. Growing conditions of the donor plants were tested with a one-step protocol and field plants produced a slightly higher percentage of embryogenesis induction than growth chamber plants. A one-step protocol was compared with a two-step protocol for embryogenesis induction. Spanish germplasm produced a 2-3 times higher percentage of embryogenesis with the two-step protocol, Recas showing the highest percentage (2.09%) and Fuentes de Ebro the lowest (0.53%). These percentages were significantly lower than those from the OH-1 population, with an average of 15% independently of the protocol used. The effect of different containers on plant regeneration was tested using both protocols. The highest percentage of acclimated plants was obtained with the two-step protocol in combination with Eco2box (70%), whereas the lowest percentage was observed with glass tubes in the two protocols (20-23%). Different amiprofos-methyl (APM) treatments were applied to embryos for chromosome doubling. A similar number of doubled haploid plants were recovered with 25 or 50 μM APM in liquid medium. However, the application of 25 μM in solid medium for 24 h produced the highest number of doubled haploid plants. Somatic regeneration from flower buds of haploid and mixoploid plants proved to be a successful approach for chromosome doubling, since diploid plants were obtained from the four regenerated lines. In this study, doubled haploid plants were produced from the four Spanish cultivars, however further improvements are needed to increase their gynogenesis efficiency.

Androgenesis in Solanaceae.

PubMed

Seguí-Simarro, Jose M

2016-01-01

The Solanaceae is one of the most important families for global agriculture. Among the different solanaceous species, tobacco (Nicotiana tabacum), potato (Solanum tuberosum), tomato (Solanum lycopersicum), eggplant (Solanum melongena), and pepper (Capsicum annuum) are five crops of outstanding importance worldwide. In these crops, maximum yields are produced by hybrid plants created by crossing pure (homozygous) lines with the desired traits. Pure lines may be produced by conventional breeding methods, which is time consuming and costly. Alternatively, it is possible to accelerate the production of pure lines by creating doubled haploid (DH) plants derived from (haploid) male gametophytes or their precursors (androgenesis). In this way, the different steps for the production of pure lines can be reduced to only one generation, which implies important time and cost savings. This and other advantages make androgenic DHs the choice in a number of important crops where any of the different experimental in vitro techniques (anther culture or isolated microspore culture) is well set up. The Solanaceae family is an excellent example of heterogeneity in terms of response to these techniques, including highly responding species such as tobacco, considered a model system, and tomato, one of the most recalcitrant species, where no reliable and reproducible methods are yet available. Interestingly, the first evidence of androgenesis, particularly through in vitro anther culture, was demonstrated in a solanaceous species, Datura innoxia. In this chapter, we report the state of the art of the research about androgenic DHs in Solanaceae, paying special attention to datura, tobacco, potato, tomato, eggplant, and pepper.

Vaccine adverse events in a safety net healthcare system and a managed care organization.

PubMed

Narwaney, Komal J; Breslin, Kristin; Ross, Colleen A; Shoup, Jo Ann; Wain, Kris F; Weintraub, Eric S; McNeil, Michael M; Hambidge, Simon J

2017-03-01

The Institute of Medicine, in a 2013 report, recommended that the Vaccine Safety Datalink (VSD) expand collaborations to include more diversity in the study population. Kaiser Permanente Colorado (KPCO), an established VSD site, partnered with Denver Health (DH), an integrated safety net healthcare system, to demonstrate the feasibility of integrating DH data within the VSD. Prior to incorporating the data, we examined the identification of specific vaccine associated adverse events (VAEs) in these two distinct healthcare systems. We conducted retrospective cohort analyses within KPCO and DH to compare select VAEs between the two populations. We examined the following associations between January 1, 2004 and December 31, 2013: Measles, Mumps, and Rubella (MMR) vaccine and febrile seizures in children 2years and younger, intussusception after rotavirus vaccine in infants 4-34weeks, syncope after adolescent vaccines (Tetanus, Diphtheria, acellular Pertussis; Meningococcal and Human Papillomavirus) in adolescents 13-17years and medically attended local reactions after pneumococcal polysaccharide (PPSV23) vaccine in adults 65years and older. Both sites used similar data procurement methods and chart review processes. For seizures after MMR vaccine (KPCO - 3.15vs. DH - 2.97/10,000 doses) and syncope after all adolescent vaccines (KPCO - 3.0vs. DH - 2.37/10,000 doses), the chart confirmed rates were comparable at the two sites. However, for medically attended local reactions after PPSV23, there were differences in chart confirmed rates between the sites (KPCO - 31.65vs. DH - 14.90/10,000 doses). For intussusception after rotavirus vaccine, the number of cases was too low to make a valid comparison (KPCO - 0vs. DH - 0.13/10,000 doses). We demonstrated that data on important targeted VAEs can be captured at DH and rates appear similar to those at KPCO. Work is ongoing on the optimal approach to assimilate DH data as a potential safety net healthcare system in the VSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Divergence hitchhiking and the spread of genomic isolation during ecological speciation-with-gene-flow

PubMed Central

Via, Sara

2012-01-01

In allopatric populations, geographical separation simultaneously isolates the entire genome, allowing genetic divergence to accumulate virtually anywhere in the genome. In sympatric populations, however, the strong divergent selection required to overcome migration produces a genetic mosaic of divergent and non-divergent genomic regions. In some recent genome scans, each divergent genomic region has been interpreted as an independent incidence of migration/selection balance, such that the reduction of gene exchange is restricted to a few kilobases around each divergently selected gene. I propose an alternative mechanism, ‘divergence hitchhiking’ (DH), in which divergent selection can reduce gene exchange for several megabases around a gene under strong divergent selection. Not all genes/markers within a DH region are divergently selected, yet the entire region is protected to some degree from gene exchange, permitting genetic divergence from mechanisms other than divergent selection to accumulate secondarily. After contrasting DH and multilocus migration/selection balance (MM/SB), I outline a model in which genomic isolation at a given genomic location is jointly determined by DH and genome-wide effects of the progressive reduction in realized migration, then illustrate DH using data from several pairs of incipient species in the wild. PMID:22201174

One haploid parent contributes 100% of the gene pool for a widespread species in northwest North America.

PubMed

Karlin, E F; Andrus, R E; Boles, S B; Shaw, A J

2011-02-01

The monoicous peatmoss Sphagnum subnitens has a tripartite distribution that includes disjunct population systems in Europe (including the Azores), northwestern North America and New Zealand. Regional genetic diversity was highest in European S. subnitens but in northwestern North America, a single microsatellite-based multilocus haploid genotype was detected across 16 sites ranging from Coos County, Oregon, to Kavalga Island in the Western Aleutians (a distance of some 4115 km). Two multilocus haploid genotypes were detected across 14 sites on South Island, New Zealand. The microsatellite-based regional genetic diversity detected in New Zealand and North American S. subnitens is the lowest reported for any Sphagnum. The low genetic diversity detected in both of these regions most likely resulted from a founder event associated with vegetative propagation and complete selfing, with one founding haploid plant in northwest North America and two in New Zealand. Thus, one plant appears to have contributed 100% of the gene pool for the population systems of S. subnitens occurring in northwest North America, and this is arguably the most genetically uniform group of plants having a widespread distribution yet detected. Although having a distribution spanning 12.5° of latitude and 56° of longitude, there was no evidence of any genetic diversification in S. subnitens in northwest North America. No genetic structure was detected among the three regions, and it appears that European plants of S. subnitens provided the source for New Zealand and northwest North American populations. © 2010 Blackwell Publishing Ltd.

Sexy males and sexless females: the origin of triploid apomicts.

PubMed

Muralidhar, P; Haig, D

2017-05-01

Apomixis and polyploidy are closely associated in angiosperms, but the evolutionary reason for this association is unknown. Taraxacum officinale, the common dandelion, exists both as diploid sexuals and triploid apomicts. Here, in the context of T. officinale, we provide a model of the evolution of triploid apomicts from diploid sexuals. We posit an apomictic allele that arrests female meiosis in diploids, so that the plant produces diploid egg cells that can develop without fertilization, but haploid pollen. We propose occasional fertilization of diploid egg cells by haploid pollen, resulting in triploid apomicts that produce triploid egg cells but largely nonfunctional pollen. The irreversibility of this process renders diploid partial apomicts evolutionarily short-lived, and results in fixation of triploid apomicts except when they suffer extreme selective disadvantages. Our model can account for the high genetic diversity found in T. officinale triploid populations, because recombinant haploid pollen produced by diploids allows the apomictic allele to spread onto many genetic backgrounds. This leads to multiple clonal lineages in the newly apomictic population, and thereby alleviates some of the usual pitfalls of asexual reproduction.

Extraordinary Genetic Diversity in a Wood Decay Mushroom.

PubMed

Baranova, Maria A; Logacheva, Maria D; Penin, Aleksey A; Seplyarskiy, Vladimir B; Safonova, Yana Y; Naumenko, Sergey A; Klepikova, Anna V; Gerasimov, Evgeny S; Bazykin, Georgii A; James, Timothy Y; Kondrashov, Alexey S

2015-10-01

Populations of different species vary in the amounts of genetic diversity they possess. Nucleotide diversity π, the fraction of nucleotides that are different between two randomly chosen genotypes, has been known to range in eukaryotes between 0.0001 in Lynx lynx and 0.16 in Caenorhabditis brenneri. Here, we report the results of a comparative analysis of 24 haploid genotypes (12 from the United States and 12 from European Russia) of a split-gill fungus Schizophyllum commune. The diversity at synonymous sites is 0.20 in the American population of S. commune and 0.13 in the Russian population. This exceptionally high level of nucleotide diversity also leads to extreme amino acid diversity of protein-coding genes. Using whole-genome resequencing of 2 parental and 17 offspring haploid genotypes, we estimate that the mutation rate in S. commune is high, at 2.0 × 10(-8) (95% CI: 1.1 × 10(-8) to 4.1 × 10(-8)) per nucleotide per generation. Therefore, the high diversity of S. commune is primarily determined by its elevated mutation rate, although high effective population size likely also plays a role. Small genome size, ease of cultivation and completion of the life cycle in the laboratory, free-living haploid life stages and exceptionally high variability of S. commune make it a promising model organism for population, quantitative, and evolutionary genetics. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The Hidden Sexuality of Alexandrium Minutum: An Example of Overlooked Sex in Dinoflagellates.

PubMed

Figueroa, Rosa I; Dapena, Carlos; Bravo, Isabel; Cuadrado, Angeles

2015-01-01

Dinoflagellates are haploid eukaryotic microalgae in which rapid proliferation causes dense blooms, with harmful health and economic effects to humans. The proliferation mode is mainly asexual, as the sexual cycle is believed to be rare and restricted to stressful environmental conditions. However, sexuality is key to explaining the recurrence of many dinoflagellate blooms because in many species the fate of the planktonic zygotes (planozygotes) is the formation of resistant cysts in the seabed (encystment). Nevertheless, recent research has shown that individually isolated planozygotes in the lab can enter other routes besides encystment, a behavior of which the relevance has not been explored at the population level. In this study, using imaging flow cytometry, cell sorting, and Fluorescence In Situ Hybridization (FISH), we followed DNA content and nuclear changes in a population of the toxic dinoflagellate Alexandrium minutum that was induced to encystment. Our results first show that planozygotes behave like a population with an "encystment-independent" division cycle, which is light-controlled and follows the same Light:Dark (L:D) pattern as the cycle governing the haploid mitosis. Resting cyst formation was the fate of just a small fraction of the planozygotes formed and was restricted to a period of strongly limited nutrient conditions. The diploid-haploid turnover between L:D cycles was consistent with two-step meiosis. However, the diel and morphological division pattern of the planozygote division also suggests mitosis, which would imply that this species is not haplontic, as previously considered, but biphasic, because individuals could undergo mitotic divisions in both the sexual (diploid) and the asexual (haploid) phases. We also report incomplete genome duplication processes. Our work calls for a reconsideration of the dogma of rare sex in dinoflagellates.

The Hidden Sexuality of Alexandrium Minutum: An Example of Overlooked Sex in Dinoflagellates

PubMed Central

Figueroa, Rosa I.; Dapena, Carlos; Bravo, Isabel; Cuadrado, Angeles

2015-01-01

Dinoflagellates are haploid eukaryotic microalgae in which rapid proliferation causes dense blooms, with harmful health and economic effects to humans. The proliferation mode is mainly asexual, as the sexual cycle is believed to be rare and restricted to stressful environmental conditions. However, sexuality is key to explaining the recurrence of many dinoflagellate blooms because in many species the fate of the planktonic zygotes (planozygotes) is the formation of resistant cysts in the seabed (encystment). Nevertheless, recent research has shown that individually isolated planozygotes in the lab can enter other routes besides encystment, a behavior of which the relevance has not been explored at the population level. In this study, using imaging flow cytometry, cell sorting, and Fluorescence In Situ Hybridization (FISH), we followed DNA content and nuclear changes in a population of the toxic dinoflagellate Alexandrium minutum that was induced to encystment. Our results first show that planozygotes behave like a population with an “encystment-independent” division cycle, which is light-controlled and follows the same Light:Dark (L:D) pattern as the cycle governing the haploid mitosis. Resting cyst formation was the fate of just a small fraction of the planozygotes formed and was restricted to a period of strongly limited nutrient conditions. The diploid-haploid turnover between L:D cycles was consistent with two-step meiosis. However, the diel and morphological division pattern of the planozygote division also suggests mitosis, which would imply that this species is not haplontic, as previously considered, but biphasic, because individuals could undergo mitotic divisions in both the sexual (diploid) and the asexual (haploid) phases. We also report incomplete genome duplication processes. Our work calls for a reconsideration of the dogma of rare sex in dinoflagellates. PMID:26599692

Three-Step Method for Proliferation and Differentiation of Human Embryonic Stem Cell (hESC)-Derived Male Germ Cells

PubMed Central

Lim, Jung Jin; Shim, Myung Sun; Lee, Jeoung Eun; Lee, Dong Ryul

2014-01-01

The low efficiency of differentiation into male germ cell (GC)-like cells and haploid germ cells from human embryonic stem cells (hESCs) reflects the culture method employed in the two-dimensional (2D)-microenvironment. In this study, we applied a three-step media and calcium alginate-based 3D-culture system for enhancing the differentiation of hESCs into male germ stem cell (GSC)-like cells and haploid germ cells. In the first step, embryoid bodies (EBs) were derived from hESCs cultured in EB medium for 3 days and re-cultured for 4 additional days in EB medium with BMP4 and RA to specify GSC-like cells. In the second step, the resultant cells were cultured in GC-proliferation medium for 7 days. The GSC-like cells were then propagated after selection using GFR-α1 and were further cultured in GC-proliferation medium for 3 weeks. In the final step, a 3D-co-culture system using calcium alginate encapsulation and testicular somatic cells was applied to induce differentiation into haploid germ cells, and a culture containing approximately 3% male haploid germ cells was obtained after 2 weeks of culture. These results demonstrated that this culture system could be used to efficiently induce GSC-like cells in an EB population and to promote the differentiation of ESCs into haploid male germ cells. PMID:24690677

ISSR marker-assisted genetic diversity analysis of Dioscorea hispida and selection of the best variety for sustainable production.

PubMed

Nudin, Nur Fatihah Hasan; Ali, Abdul Manaf; Ngah, Norhayati; Mazlan, Nor Zuhailah; Mat, Nashriyah; Ghani, Mohd Noor Abd; Alias, Nadiawati; Zakaria, Abd Jamil; Jahan, Md Sarwar

2017-08-01

Plant breeding is a way of selection of a particular individual for the production of the progeny by separating or combining desired characteristics. The objective of this study was to justify different characteristics of Dioscorea hispida (Ubi gadong) varieties using molecular techniques to select the best variety for sustainable production at the farmer's level. A total of 160 germplasms of Ubi gadong were collected from different locations at the Terengganu and Kelantan states of Malaysia. Forty eight (48) out of 160 germplasms were selected as "primary" selection based on yield and other qualitative characters. Selected collections were then grown and maintained for ISSR marker-assisted genetic diversity analysis. Overall plant growth and yield of tubers were also determined. A total of 12 ISSR markers were tested to justify the characteristics of Ubi gadong varieties among which three markers showed polymorphic bands and on average 57.3% polymorphism were observed representing the highest variation among germplasms. The ISSR marker based on UPGMA cluster analysis grouped all 48 D. hispida into 10 vital groups that proved a vast genetic variation among germplasm collections. Therefore, hybridization should be made between two distant populations. The D. hispida is already proved as the highest starch content tuber crops and very rich in vitamins with both micro and macro minerals. Considering all these criteria and results from marker-assisted diversity analysis, accessions that are far apart based on their genetic coefficient (like DH27 and DH71; DH30 and DH70; DH43 and DH62; DH45 and DH61; DH77 and DH61; DH78 and DH57) could be selected as parents for further breeding programs. This will bring about greater diversity, which will lead to high productive index in terms of increase in yield and overall quality and for the ultimate target of sustainable Ubi gadong production. Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Quality of Life and Gastrointestinal Symptoms in Long-Term Treated Dermatitis Herpetiformis Patients: A Cross-Sectional Study in Finland.

PubMed

Pasternack, Camilla; Kaukinen, Katri; Kurppa, Kalle; Mäki, Markku; Collin, Pekka; Reunala, Timo; Huhtala, Heini; Salmi, Teea

2015-12-01

Dermatitis herpetiformis (DH) is a cutaneous manifestation of celiac disease. Both conditions are treated with a restrictive life-long gluten-free diet (GFD). Treated celiac disease patients have been shown to have more severe gastrointestinal symptoms and inferior quality of life compared with healthy controls, but evidence regarding quality of life in DH is lacking. The aim was to evaluate whether long-term GFD-treated DH patients suffer from persistent gastrointestinal symptoms and if they experience a drawdown in quality of life. Gastrointestinal symptoms and quality of life were assessed in 78 long-term GFD-treated DH patients using the validated Gastrointestinal Symptom Rating Scale, Psychological General Well-Being and Short Form 36 Health Survey questionnaires. The findings were compared with 110 healthy controls, population-based reference values and 371 treated celiac disease controls. The median age of the DH patients at the time of the study was 57 years, and 51 % were male. Significant differences in gastrointestinal symptoms or quality of life were not detected when treated DH patients were compared with healthy controls, but treated DH patients had less severe gastrointestinal symptoms and increased quality of life compared with celiac disease controls. Female DH patients had more severe gastrointestinal symptoms and reduced vitality compared with male DH patients. The presence of skin symptoms and the adherence to or duration of GFD did not have any influence on gastrointestinal symptoms or quality of life. We conclude that long-term GFD-treated DH patients do not suffer from the burden of dietary treatment and have a quality of life comparable to that of controls.

Relationship between QTL for grain shape, grain weight, test weight, milling yield, and plant height in the spring wheat cross RL4452/'AC Domain'.

PubMed

Cabral, Adrian L; Jordan, Mark C; Larson, Gary; Somers, Daryl J; Humphreys, D Gavin; McCartney, Curt A

2018-01-01

Kernel morphology characteristics of wheat are complex and quantitatively inherited. A doubled haploid (DH) population of the cross RL4452/'AC Domain' was used to study the genetic basis of seed shape. Quantitative trait loci (QTL) analyses were conducted on a total of 18 traits: 14 grain shape traits, flour yield (Fyd), and three agronomic traits (Plant height [Plht], 1000 Grain weight [Gwt], Test weight [Twt]), using data from trial locations at Glenlea, Brandon, and Morden in Manitoba, Canada, between 1999 and 2004. Kernel shape was studied through digital image analysis with an Acurum® grain analyzer. Plht, Gwt, Twt, Fyd, and grain shape QTL were correlated with each other and QTL analysis revealed that QTL for these traits often mapped to the same genetic locations. The most significant QTL for the grain shape traits were located on chromosomes 4B and 4D, each accounting for up to 24.4% and 53.3% of the total phenotypic variation, respectively. In addition, the most significant QTL for Plht, Gwt, and Twt were all detected on chromosome 4D at the Rht-D1 locus. Rht-D1b decreased Plht, Gwt, Twt, and kernel width relative to the Rht-D1a allele. A narrow genetic interval on chromosome 4B contained significant QTL for grain shape, Gwt, and Plht. The 'AC Domain' allele reduced Plht, Gwt, kernel length and width traits, but had no detectable effect on Twt. The data indicated that this variation was inconsistent with segregation at Rht-B1. Numerous QTL were identified that control these traits in this population.

Relationship between QTL for grain shape, grain weight, test weight, milling yield, and plant height in the spring wheat cross RL4452/‘AC Domain’

PubMed Central

Cabral, Adrian L.; Jordan, Mark C.; Larson, Gary; Somers, Daryl J.; Humphreys, D. Gavin

2018-01-01

Kernel morphology characteristics of wheat are complex and quantitatively inherited. A doubled haploid (DH) population of the cross RL4452/‘AC Domain’ was used to study the genetic basis of seed shape. Quantitative trait loci (QTL) analyses were conducted on a total of 18 traits: 14 grain shape traits, flour yield (Fyd), and three agronomic traits (Plant height [Plht], 1000 Grain weight [Gwt], Test weight [Twt]), using data from trial locations at Glenlea, Brandon, and Morden in Manitoba, Canada, between 1999 and 2004. Kernel shape was studied through digital image analysis with an Acurum® grain analyzer. Plht, Gwt, Twt, Fyd, and grain shape QTL were correlated with each other and QTL analysis revealed that QTL for these traits often mapped to the same genetic locations. The most significant QTL for the grain shape traits were located on chromosomes 4B and 4D, each accounting for up to 24.4% and 53.3% of the total phenotypic variation, respectively. In addition, the most significant QTL for Plht, Gwt, and Twt were all detected on chromosome 4D at the Rht-D1 locus. Rht-D1b decreased Plht, Gwt, Twt, and kernel width relative to the Rht-D1a allele. A narrow genetic interval on chromosome 4B contained significant QTL for grain shape, Gwt, and Plht. The ‘AC Domain’ allele reduced Plht, Gwt, kernel length and width traits, but had no detectable effect on Twt. The data indicated that this variation was inconsistent with segregation at Rht-B1. Numerous QTL were identified that control these traits in this population. PMID:29357369

Prevalence of dentine hypersensitivity and study of associated factors: a European population-based cross-sectional study.

PubMed

West, Nicola Xania; Sanz, Mariano; Lussi, Adrian; Bartlett, David; Bouchard, Phillipe; Bourgeois, Denis

2013-10-01

Dentine hypersensitivity (DH) manifests as a transient but arresting oral pain. The incidence is thought to be rising, particularly in young adults, due to increases in consumption of healthy, yet erosive, diets. This study aimed to assess the prevalence of DH and relative importance of risk factors, in 18-35 year old Europeans. In 2011, 3187 adults were enrolled from general dental practices in France, Spain, Italy, United Kingdom, Finland, Latvia and Estonia. DH was clinically evaluated by cold air tooth stimulation, patient pain rating (yes/no), accompanied by investigator pain rating (Schiff 0-3). Erosive toothwear (BEWE index 0-3) and gingival recession (mm) were recorded. Patients completed a questionnaire regarding the nature of their DH, erosive dietary intake and toothbrushing habits. 41.9% of patients reported pain on tooth stimulation and 56.8% scored ≥1 on Schiff scale for at least one tooth. Clinical elicited sensitivity was closely related to Schiff score and to a lesser degree, questionnaire reported sensitivity (26.8%), possibly reflecting the transient nature of the pain, alongside good coping mechanisms. Significant associations were found between clinically elicited DH and erosive toothwear and gingival recession. The questionnaire showed marked associations between DH and risk factors including heartburn/acid reflux, vomiting, sleeping medications, energy drinks, smoking and acid dietary intake. Overall, the prevalence of DH was high compared to many published findings, with a strong, progressive relationship between DH and erosive toothwear, which is important to recognise for patient preventive therapies and clinical management of DH pain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Agrobacterium tumefaciens-mediated transformation for investigation of somatic recombination in the fungal pathogen Armillaria mellea.

PubMed

Baumgartner, Kendra; Fujiyoshi, Phillip; Foster, Gary D; Bailey, Andy M

2010-12-01

Armillaria root disease is one of the most damaging timber and fruit tree diseases in the world. Despite its economic importance, many basic questions about the biology of the causal fungi, Armillaria spp., are unanswered. For example, Armillaria undergoes matings between diploid and haploid mycelia, which can result in a recombinant diploid without meiosis. Evidence of such somatic recombination in natural populations suggests that this reproductive mode may affect the pathogen's ecology. Investigations of the mechanisms and adaptive consequences of somatic recombination are, however, hampered by the lack of a method to reliably synthesize somatic recombinants. Here we report the first genetic transformation system for the genus Armillaria. We transformed A. mellea with selective markers for use in diploid-haploid matings to reliably synthesize somatic recombinants. This was accomplished with Agrobacterium tumefaciens carrying pBGgHg, which carries the hygromycin phosphotransferase gene (hph). hph was integrated into transformants, as evidenced by serial transfer to selective media, PCR, reverse transcription-PCR (RT-PCR), and Southern hybridization. Nuclear and mitochondrial markers were developed to genotype synthesized mycelia. In matings between a wild-type diploid and hygromycin-resistant haploids (transgenic), we identified recombinant, hygromycin-resistant diploids and, additionally, hygromycin-resistant triploids, all with the mitochondrial haplotype of the haploid partner. Our approach created no mycelium in which the haploid nucleus was replaced by the diploid nucleus, the typical outcome of diploid-haploid matings in Armillaria. This genetic transformation system, in combination with new markers to track chromosomal and cytoplasmic inheritance in A. mellea, will advance research aimed at characterizing the significance of somatic recombination in the ecology of this important fungus.

Characterization of in vitro haploid and doubled haploid Chrysanthemum morifolium plants via unfertilized ovule culture for phenotypical traits and DNA methylation pattern

PubMed Central

Wang, Haibin; Dong, Bin; Jiang, Jiafu; Fang, Weimin; Guan, Zhiyong; Liao, Yuan; Chen, Sumei; Chen, Fadi

2014-01-01

Chrysanthemum is one of important ornamental species in the world. Its highly heterozygous state complicates molecular analysis, so it is of interest to derive haploid forms. A total of 2579 non-fertilized chrysanthemum ovules pollinated by Argyranthemum frutescens were cultured in vitro to isolate haploid progeny. One single regenerant emerged from each of three of the 105 calli produced. Chromosome counts and microsatellite fingerprinting showed that only one of the regenerants was a true haploid. Nine doubled haploid derivatives were subsequently generated by colchicine treatment of 80 in vitro cultured haploid nodal segments. Morphological screening showed that the haploid plant was shorter than the doubled haploids, and developed smaller leaves, flowers, and stomata. An in vitro pollen germination test showed that few of the haploid's pollen were able to germinate and those which did so were abnormal. Both the haploid and the doubled haploids produced yellow flowers, whereas those of the maternal parental cultivar were mauve. Methylation-sensitive amplification polymorphism (MSAP) profiling was further used to detect alterations in cytosine methylation caused by the haploidization and/or the chromosome doubling processes. While 52.2% of the resulting amplified fragments were cytosine methylated in the maternal parent's genome, the corresponding proportions for the haploid's and doubled haploids' genomes were, respectively, 47.0 and 51.7%, demonstrating a reduction in global cytosine methylation caused by haploidization and a partial recovery following chromosome doubling. PMID:25566305

Poppr: an R package for genetic analysis of populations with mixed (clonal/sexual) reproduction

USDA-ARS?s Scientific Manuscript database

Poppr is an R package for analysis of population genetic data. It extends the adegenet package and provides several novel tools, particularly with regard to analysis of data from admixed, clonal, and/or sexual populations. Currently, poppr can be used for dominant/codominant and haploid/diploid gene...

Combination of reversible male sterility and doubled haploid production by targeted inactivation of cytoplasmic glutamine synthetase in developing anthers and pollen.

PubMed

Ribarits, Alexandra; Mamun, A N K; Li, Shipeng; Resch, Tatiana; Fiers, Martijn; Heberle-Bors, Erwin; Liu, Chun-Ming; Touraev, Alisher

2007-07-01

Reversible male sterility and doubled haploid plant production are two valuable technologies in F(1)-hybrid breeding. F(1)-hybrids combine uniformity with high yield and improved agronomic traits, and provide self-acting intellectual property protection. We have developed an F(1)-hybrid seed technology based on the metabolic engineering of glutamine in developing tobacco anthers and pollen. Cytosolic glutamine synthetase (GS1) was inactivated in tobacco by introducing mutated tobacco GS genes fused to the tapetum-specific TA29 and microspore-specific NTM19 promoters. Pollen in primary transformants aborted close to the first pollen mitosis, resulting in male sterility. A non-segregating population of homozygous doubled haploid male-sterile plants was generated through microspore embryogenesis. Fertility restoration was achieved by spraying plants with glutamine, or by pollination with pollen matured in vitro in glutamine-containing medium. The combination of reversible male sterility with doubled haploid production results in an innovative environmentally friendly breeding technology. Tapetum-mediated sporophytic male sterility is of use in foliage crops, whereas microspore-specific gametophytic male sterility can be applied to any field crop. Both types of sterility preclude the release of transgenic pollen into the environment.

Recovery and characterization of a Citrus clementina Hort. ex Tan. 'Clemenules' haploid plant selected to establish the reference whole Citrus genome sequence.

PubMed

Aleza, Pablo; Juárez, José; Hernández, María; Pina, José A; Ollitrault, Patrick; Navarro, Luis

2009-08-22

In recent years, the development of structural genomics has generated a growing interest in obtaining haploid plants. The use of homozygous lines presents a significant advantage for the accomplishment of sequencing projects. Commercial citrus species are characterized by high heterozygosity, making it difficult to assemble large genome sequences. Thus, the International Citrus Genomic Consortium (ICGC) decided to establish a reference whole citrus genome sequence from a homozygous plant. Due to the existence of important molecular resources and previous success in obtaining haploid clementine plants, haploid clementine was selected as the target for the implementation of the reference whole genome citrus sequence. To obtain haploid clementine lines we used the technique of in situ gynogenesis induced by irradiated pollen. Flow cytometry, chromosome counts and SSR marker (Simple Sequence Repeats) analysis facilitated the identification of six different haploid lines (2n = x = 9), one aneuploid line (2n = 2x+4 = 22) and one doubled haploid plant (2n = 2x = 18) of 'Clemenules' clementine. One of the haploids, obtained directly from an original haploid embryo, grew vigorously and produced flowers after four years. This is the first haploid plant of clementine that has bloomed and we have, for the first time, characterized the histology of haploid and diploid flowers of clementine. Additionally a double haploid plant was obtained spontaneously from this haploid line. The first haploid plant of 'Clemenules' clementine produced directly by germination of a haploid embryo, which grew vigorously and produced flowers, has been obtained in this work. This haploid line has been selected and it is being used by the ICGC to establish the reference sequence of the nuclear genome of citrus.

Global projections of drought hazard in a warming climate: a prime for disaster risk management

NASA Astrophysics Data System (ADS)

Carrão, Hugo; Naumann, Gustavo; Barbosa, Paulo

2018-03-01

Projections of drought hazard ( dH) changes have been mapped from five bias-corrected climate models and analyzed at the global level under three representative concentration pathways (RCPs). The motivation for this study is the observation that drought risk is increasing globally and the effective regulation of prevention and adaptation measures depends on dH magnitude and its distribution for the future. Based on the Weighted Anomaly of Standardized Precipitation index, dH changes have been assessed for mid-(2021-2050) and late-century (2071-2099). With a few exceptions, results show a likely increase in global dH between the historical years (1971-2000) and both future time periods under all RCPs. Notwithstanding this worsening trend, it was found that projections of dH changes for most regions are neither robust nor significant in the near-future. By the end of the century, greater increases are projected for RCPs describing stronger radiative forcing. Under RCP8.5, statistically significant dH changes emerge for global Mediterranean ecosystems and the Amazon region, which are identified as possible hotspots for future water security issues. Taken together, projections of dH changes point towards two dilemmas: (1) in the near-term, stake-holders are left worrying about projected increasing dH over large regions, but lack of actionable model agreement to take effective decisions related to local prevention and adaptation initiatives; (2) in the long-term, models demonstrate remarkable agreement, but stake-holders lack actionable knowledge to manage potential impacts far distant from actual human-dominated environments. We conclude that the major challenge for risk management is not to adapt human populations or their activities to dH changes, but to progress on global initiatives that mitigate their impacts in the whole carbon cycle by late-century.

Closing the Health Care Gap in Communities: A Safety Net System Approach.

PubMed

Gabow, Patricia A

2016-10-01

The goal of U.S. health care should be good health for every American. This daunting goal will require closing the health care gap in communities with a particular focus on the most vulnerable populations and the safety net institutions that disproportionately serve these communities. This Commentary describes Denver Health's (DH's) two-pronged approach to achieving this goal: (1) creating an integrated system that focuses on the needs of vulnerable populations, and (2) creating an approach for financial viability, quality of care, and employee engagement. The implementation and outcomes of this approach at DH are described to provide a replicable model. An integrated delivery system serving vulnerable populations should go beyond the traditional components found in most integrated health systems and include components such as mental health services, school-based clinics, and correctional health care, which address the unique and important needs of, and points of access for, vulnerable populations. In addition, the demands that a safety net system experiences from an open-door policy on access and revenue require a disciplined approach to cost, quality of care, and employee engagement. For this, DH chose Lean, which focuses on reducing waste to respect the patients and employees within its health system, as well as all citizens. DH's Lean effort produced almost $195 million of financial benefit, impressive clinical outcomes, and high employee engagement. If this two-pronged approach were widely adopted, health systems across the United States would improve their chances of giving better care at costs they can afford for every person in society.

A p53-dependent response limits the viability of mammalian haploid cells

PubMed Central

Olbrich, Teresa; Mayor-Ruiz, Cristina; Vega-Sendino, Maria; Gomez, Carmen; Ortega, Sagrario; Ruiz, Sergio; Fernandez-Capetillo, Oscar

2017-01-01

The recent development of haploid cell lines has facilitated forward genetic screenings in mammalian cells. These lines include near-haploid human cell lines isolated from a patient with chronic myelogenous leukemia (KBM7 and HAP1), as well as haploid embryonic stem cells derived from several organisms. In all cases, haploidy was shown to be an unstable state, so that cultures of mammalian haploid cells rapidly become enriched in diploids. Here we show that the observed diploidization is due to a proliferative disadvantage of haploid cells compared with diploid cells. Accordingly, single-cell–sorted haploid mammalian cells maintain the haploid state for prolonged periods, owing to the absence of competing diploids. Although the duration of interphase is similar in haploid and diploid cells, haploid cells spend longer in mitosis, indicative of problems in chromosome segregation. In agreement with this, a substantial proportion of the haploids die at or shortly after the last mitosis through activation of a p53-dependent cytotoxic response. Finally, we show that p53 deletion stabilizes haploidy in human HAP1 cells and haploid mouse embryonic stem cells. We propose that, similar to aneuploidy or tetraploidy, haploidy triggers a p53-dependent response that limits the fitness of mammalian cells. PMID:28808015

A Herschel Study of D/H in Water in the Jupiter-family Comet 45P/Honda-Mrkos-Pajdušáková and Prospects for D/H Measurements with CCAT

NASA Astrophysics Data System (ADS)

Lis, D. C.; Biver, N.; Bockelée-Morvan, D.; Hartogh, P.; Bergin, E. A.; Blake, G. A.; Crovisier, J.; de Val-Borro, M.; Jehin, E.; Küppers, M.; Manfroid, J.; Moreno, R.; Rengel, M.; Szutowicz, S.

2013-09-01

We present Herschel observations of water isotopologues in the atmosphere of the Jupiter-family comet 45P/Honda-Mrkos-Pajdušáková. No HDO emission is detected, with a 3σ upper limit of 2.0 × 10-4 for the D/H ratio. This value is consistent with the earlier Herschel measurement in the Jupiter-family comet 103P/Hartley 2. The canonical value of 3 × 10-4 measured pre-Herschel in a sample of Oort-cloud comets can be excluded at a 4.5σ level. The observations presented here further confirm that a diversity of D/H ratios exists in the comet population and emphasize the need for additional measurements with future ground-based facilities, such as CCAT, in the post-Herschel era.

A HERSCHEL STUDY OF D/H IN WATER IN THE JUPITER-FAMILY COMET 45P/HONDA-MRKOS-PAJDUSAKOVA AND PROSPECTS FOR D/H MEASUREMENTS WITH CCAT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lis, D. C.; Blake, G. A.; Biver, N.

We present Herschel observations of water isotopologues in the atmosphere of the Jupiter-family comet 45P/Honda-Mrkos-Pajdusakova. No HDO emission is detected, with a 3{sigma} upper limit of 2.0 Multiplication-Sign 10{sup -4} for the D/H ratio. This value is consistent with the earlier Herschel measurement in the Jupiter-family comet 103P/Hartley 2. The canonical value of 3 Multiplication-Sign 10{sup -4} measured pre-Herschel in a sample of Oort-cloud comets can be excluded at a 4.5{sigma} level. The observations presented here further confirm that a diversity of D/H ratios exists in the comet population and emphasize the need for additional measurements with future ground-based facilities,more » such as CCAT, in the post-Herschel era.« less

Development of a diabetes prevention program for Surinamese South Asians in the Netherlands.

PubMed

Nicolaou, Mary; Vlaar, Evalina; van Valkengoed, Irene; Middelkoop, Barend; Stronks, Karien; Nierkens, Vera

2014-12-01

Type 2 diabetes is highly prevalent among South Asian origin groups around the world. Not only is prevalence higher than in other ethnic groups, age at presentation is lower and these groups are more likely to experience complications. Evidence suggests that lifestyle interventions may prevent or delay the onset of diabetes. However, little is known about diabetes prevention in South Asians (SA). DH!AAN is a diabetes prevention program designed for Surinamese SA in The Netherlands. In this paper, we describe the theoretical frameworks and formative research that guided the development and cultural adaptation of DH!AAN. Cultural adaptation was based on analysis of the determinants of diet and physical activity, including socio-cultural factors, within our study population. This led to the incorporation of surface and deep structure elements in the intervention. One-to-one counseling by dieticians using motivational interviewing (MI) was the basis for the intervention. Additionally, we aimed to generate social support by including family members in parts of the intervention and group sessions to address issues relating to traditional food habits. We discuss our reflections on the development process and the choices made in developing this intervention. The results of DH!AAN will provide insight into the use of MI for this population group. Moreover, DH!AAN will provide evidence regarding the feasibility of diabetes prevention among South Asian populations. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

REGULATION OF GEOGRAPHIC VARIABILITY IN HAPLOID:DIPLOD RATIOS OF BIPHASIC SEAWEED LIFE CYCLES(1).

PubMed

da Silva Vieira, Vasco Manuel Nobre de Carvalho; Santos, Rui Orlando Pimenta

2012-08-01

The relative abundance of haploid and diploid individuals (H:D) in isomorphic marine algal biphasic cycles varies spatially, but only if vital rates of haploid and diploid phases vary differently with environmental conditions (i.e. conditional differentiation between phases). Vital rates of isomorphic phases in particular environments may be determined by subtle morphological or physiological differences. Herein, we test numerically how geographic variability in H:D is regulated by conditional differentiation between isomorphic life phases and the type of life strategy of populations (i.e. life cycles dominated by reproduction, survival or growth). Simulation conditions were selected using available data on H:D spatial variability in seaweeds. Conditional differentiation between ploidy phases had a small effect on the H:D variability for species with life strategies that invest either in fertility or in growth. Conversely, species with life strategies that invest mainly in survival, exhibited high variability in H:D through a conditional differentiation in stasis (the probability of staying in the same size class), breakage (the probability of changing to a smaller size class) or growth (the probability of changing to a bigger size class). These results were consistent with observed geographic variability in H:D of natural marine algae populations. © 2012 Phycological Society of America.

Mixed-reproductive strategies, competitive mating-type distribution and life cycle of fourteen black morel species.

PubMed

Du, Xi-Hui; Zhao, Qi; Xia, En-Hua; Gao, Li-Zhi; Richard, Franck; Yang, Zhu L

2017-05-04

Morchella species are well known world-round as popular and prized edible fungi due to their unique culinary flavor. Recently, several species have been successfully cultivated in China. However, their reproductive modes are still unknown, and their basic biology needs to be elucidated. Here, we use the morel genome information to investigate mating systems and life cycles of fourteen black morel species. Mating type-specific primers were developed to screen and genotype ascospores, hymenia and stipes from 223 ascocarps of the 14 species from Asia and Europe. Our data indicated that they are all heterothallic and their life cycles are predominantly haploid, but sterile haploid fruiting also exists. Ascospores in all species are mostly haploid, homokaryotic, and multinuclear, whereas aborted ascospores without any nuclei were also detected. Interestingly, we monitored divergent spatial distribution of both mating types in natural morel populations and cultivated sites, where the fertile tissue of fruiting bodies usually harbored both mating types, whereas sterile tissue of wild morels constantly had one MAT allele, while the sterile tissue of cultivated strains always exhibited both MAT alleles. Furthermore, MAT1-1-1 was detected significantly more commonly than MAT1-2-1 in natural populations, which strongly suggested a competitive advantage for MAT1-1 strains.

In situ survey of life cycle phases of the coccolithophore Emiliania huxleyi (Haptophyta).

PubMed

Frada, Miguel J; Bidle, Kay D; Probert, Ian; de Vargas, Colomban

2012-06-01

The cosmopolitan coccolithophore Emiliania huxleyi is characterized by a strongly differentiated haplodiplontic life cycle consisting of a diploid phase, generally bearing coccoliths (calcified) but that can be also non-calcified, and a non-calcified biflagellated haploid phase. Given most studies have focused on the bloom-producing calcified phase, there is little-to-no information about non-calcified cells in nature. Using field mesocoms as experimental platforms, we quantitatively surveyed calcified and non-calcified cells using the combined calcareous detection fluorescent in situ hybridization (COD-FISH) method and qualitatively screened for haploid specific transcripts using reverse transcription-PCR during E. huxleyi bloom successions. Diploid, calcified cells formed dense blooms that were followed by the massive proliferation of E. huxleyi viruses (EhVs), which caused bloom demise. Non-calcified cells were also detected throughout the experiment, accounting for a minor fraction of the population but becoming progressively more abundant during mid-late bloom periods concomitant with EhV burst. Non-calcified cell growth also paralleled a distinct window of haploid-specific transcripts and the appearance of autotrophic flagellates morphologically similar to haploid cells, both of which are suggestive of meiosis and sexual life cycling during natural blooms of this prominent marine phytoplankton species. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

A quasispecies approach to the evolution of sexual replication in unicellular organisms.

PubMed

Tannenbaum, Emmanuel; Fontanari, José F

2008-03-01

This study develops a simplified model describing the evolutionary dynamics of a population composed of obligate sexually and asexually reproducing, unicellular organisms. The model assumes that the organisms have diploid genomes consisting of two chromosomes, and that the sexual organisms replicate by first dividing into haploid intermediates, which then combine with other haploids, followed by the normal mitotic division of the resulting diploid into two new daughter cells. We assume that the fitness landscape of the diploids is analogous to the single-fitness-peak approach often used in single-chromosome studies. That is, we assume a master chromosome that becomes defective with just one point mutation. The diploid fitness then depends on whether the genome has zero, one, or two copies of the master chromosome. We also assume that only pairs of haploids with a master chromosome are capable of combining so as to produce sexual diploid cells, and that this process is described by second-order kinetics. We find that, in a range of intermediate values of the replication fidelity, sexually reproducing cells can outcompete asexual ones, provided the initial abundance of sexual cells is above some threshold value. The range of values where sexual reproduction outcompetes asexual reproduction increases with decreasing replication rate and increasing population density. We critically evaluate a common approach, based on a group selection perspective, used to study the competition between populations and show its flaws in addressing the evolution of sex problem.

Comparison of RAPD Linkage Maps Constructed For a Single Longleaf Pine From Both Haploid and Diploid Mapping Populations

Treesearch

Thomas L. Kubisiak; C.Dana Nelson; W.L. Name; M. Stine

1996-01-01

Considerable concern has been voiced regarding the reproducibility/transferability of RAPD markers across different genetic backgrounds in genetic mapping experiments. Therefore, separate gametic subsets (mapping populations) were used to construct individual random amplified polymorphic DNA (RAPD) linkage maps for a single longleaf pine (Pinus palustris...

Androgenesis, gynogenesis, and parthenogenesis haploids in cucurbit species.

PubMed

Dong, Yan-Qi; Zhao, Wei-Xing; Li, Xiao-Hui; Liu, Xi-Cun; Gao, Ning-Ning; Huang, Jin-Hua; Wang, Wen-Ying; Xu, Xiao-Li; Tang, Zhen-Hai

2016-10-01

Haploids and doubled haploids are critical components of plant breeding. This review is focused on studies on haploids and double haploids inducted in cucurbits through in vitro pollination with irradiated pollen, unfertilized ovule/ovary culture, and anther/microspore culture during the last 30 years, as well as comprehensive analysis of the main factors of each process and comparison between chromosome doubling and ploidy identification methods, with special focus on the application of double haploids in plant breeding and genetics. This review identifies existing problems affecting the efficiency of androgenesis, gynogenesis, and parthenogenesis in cucurbit species. Donor plant genotypes and surrounding environments, developmental stages of explants, culture media, stress factors, and chromosome doubling and ploidy identification are compared at length and discussed as methodologies and protocols for androgenesis, gynogenesis, and parthenogenesis in haploid and double haploid production technologies.

A BASIC Program for Use in Teaching Population Dynamics.

ERIC Educational Resources Information Center

Kidd, N. A. C.

1984-01-01

Describes an interactive simulation model which can be used to demonstrate population growth with discrete or overlapping populations and the effects of random, constant, or density-dependent mortality. The program listing (for Commodore PET 4032 microcomputer) is included. (Author/DH)

Identification of two key genes controlling chill haze stability of beer in barley (Hordeum vulgare L).

PubMed

Ye, Lingzhen; Huang, Yuqing; Dai, Fei; Ning, Huajiang; Li, Chengdao; Zhou, Meixue; Zhang, Guoping

2015-06-11

In bright beer, haze formation is a serious quality problem, degrading beer quality and reducing its shelf life. The quality of barley (Hordeum vulgare L) malt, as the main raw material for beer brewing, largely affects the colloidal stability of beer. In this study, the genetic mechanism of the factors affecting beer haze stability in barley was studied. Quantitative trait loci (QTL) analysis of alcohol chill haze (ACH) in beer was carried out using a Franklin/Yerong double haploid (DH) population. One QTL, named as qACH, was detected for ACH, and it was located on the position of about 108 cM in chromosome 4H and can explain about 20 % of the phenotypic variation. Two key haze active proteins, BATI-CMb and BATI-CMd were identified by proteomics analysis. Bioinformatics analysis showed that BATI-CMb and BATI-CMd had the same position as qACH in the chromosome. It may be deduced that BATI-CMb and BATI-CMd are candidate genes for qACH, controlling colloidal stability of beer. Polymorphism comparison between Yerong and Franklin in the nucleotide and amino acid sequence of BATI-CMb and BATI-CMd detected the corresponding gene specific markers, which could be used in marker-assisted selection for malt barley breeding. We identified a novel QTL, qACH controlling chill haze of beer, and two key haze active proteins, BATI-CMb and BATI-CMd. And further analysis showed that BATI-CMb and BATI-CMd might be the candidate genes associated with beer chill haze.

QTL mapping for nine drought-responsive agronomic traits in bread wheat under irrigated and rain-fed environments

PubMed Central

Gahlaut, Vijay; Jaiswal, Vandana; Tyagi, Bhudeva S.; Singh, Gyanendra; Sareen, Sindhu; Balyan, Harindra S.

2017-01-01

In bread wheat, QTL interval mapping was conducted for nine important drought responsive agronomic traits. For this purpose, a doubled haploid (DH) mapping population derived from Kukri/Excalibur was grown over three years at four separate locations in India, both under irrigated and rain-fed environments. Single locus analysis using composite interval mapping (CIM) allowed detection of 98 QTL, which included 66 QTL for nine individual agronomic traits and 32 QTL, which affected drought sensitivity index (DSI) for the same nine traits. Two-locus analysis allowed detection of 19 main effect QTL (M-QTL) for four traits (days to anthesis, days to maturity, grain filling duration and thousand grain weight) and 19 pairs of epistatic QTL (E-QTL) for two traits (days to anthesis and thousand grain weight). Eight QTL were common in single locus analysis and two locus analysis. These QTL (identified both in single- and two-locus analysis) were distributed on 20 different chromosomes (except 4D). Important genomic regions on chromosomes 5A and 7A were also identified (5A carried QTL for seven traits and 7A carried QTL for six traits). Marker-assisted recurrent selection (MARS) involving pyramiding of important QTL reported in the present study, together with important QTL reported earlier, may be used for improvement of drought tolerance in wheat. In future, more closely linked markers for the QTL reported here may be developed through fine mapping, and the candidate genes may be identified and used for developing a better understanding of the genetic basis of drought tolerance in wheat. PMID:28793327

Haploid plants produced by centromere-mediated genome elimination.

PubMed

Ravi, Maruthachalam; Chan, Simon W L

2010-03-25

Production of haploid plants that inherit chromosomes from only one parent can greatly accelerate plant breeding. Haploids generated from a heterozygous individual and converted to diploid create instant homozygous lines, bypassing generations of inbreeding. Two methods are generally used to produce haploids. First, cultured gametophyte cells may be regenerated into haploid plants, but many species and genotypes are recalcitrant to this process. Second, haploids can be induced from rare interspecific crosses, in which one parental genome is eliminated after fertilization. The molecular basis for genome elimination is not understood, but one theory posits that centromeres from the two parent species interact unequally with the mitotic spindle, causing selective chromosome loss. Here we show that haploid Arabidopsis thaliana plants can be easily generated through seeds by manipulating a single centromere protein, the centromere-specific histone CENH3 (called CENP-A in human). When cenh3 null mutants expressing altered CENH3 proteins are crossed to wild type, chromosomes from the mutant are eliminated, producing haploid progeny. Haploids are spontaneously converted into fertile diploids through meiotic non-reduction, allowing their genotype to be perpetuated. Maternal and paternal haploids can be generated through reciprocal crosses. We have also exploited centromere-mediated genome elimination to convert a natural tetraploid Arabidopsis into a diploid, reducing its ploidy to simplify breeding. As CENH3 is universal in eukaryotes, our method may be extended to produce haploids in any plant species.

Evolution of haploid selection in predominantly diploid organisms

PubMed Central

Otto, Sarah P.; Scott, Michael F.; Immler, Simone

2015-01-01

Diploid organisms manipulate the extent to which their haploid gametes experience selection. Animals typically produce sperm with a diploid complement of most proteins and RNA, limiting selection on the haploid genotype. Plants, however, exhibit extensive expression in pollen, with actively transcribed haploid genomes. Here we analyze models that track the evolution of genes that modify the strength of haploid selection to predict when evolution intensifies and when it dampens the “selective arena” within which male gametes compete for fertilization. Considering deleterious mutations, evolution leads diploid mothers to strengthen selection among haploid sperm/pollen, because this reduces the mutation load inherited by their diploid offspring. If, however, selection acts in opposite directions in haploids and diploids (“ploidally antagonistic selection”), mothers evolve to reduce haploid selection to avoid selectively amplifying alleles harmful to their offspring. Consequently, with maternal control, selection in the haploid phase either is maximized or reaches an intermediate state, depending on the deleterious mutation rate relative to the extent of ploidally antagonistic selection. By contrast, evolution generally leads diploid fathers to mask mutations in their gametes to the maximum extent possible, whenever masking (e.g., through transcript sharing) increases the average fitness of a father’s gametes. We discuss the implications of this maternal–paternal conflict over the extent of haploid selection and describe empirical studies needed to refine our understanding of haploid selection among seemingly diploid organisms. PMID:26669442

Stripe rust and leaf rust resistance QTL mapping, epistatic interactions, and co-localization with stem rust resistance loci in spring wheat evaluated over three continents.

PubMed

Singh, A; Knox, R E; DePauw, R M; Singh, A K; Cuthbert, R D; Campbell, H L; Shorter, S; Bhavani, S

2014-11-01

In wheat, advantageous gene-rich or pleiotropic regions for stripe, leaf, and stem rust and epistatic interactions between rust resistance loci should be accounted for in plant breeding strategies. Leaf rust (Puccinia triticina Eriks.) and stripe rust (Puccinia striiformis f. tritici Eriks) contribute to major production losses in many regions worldwide. The objectives of this research were to identify and study epistatic interactions of quantitative trait loci (QTL) for stripe and leaf rust resistance in a doubled haploid (DH) population derived from the cross of Canadian wheat cultivars, AC Cadillac and Carberry. The relationship of leaf and stripe rust resistance QTL that co-located with stem rust resistance QTL previously mapped in this population was also investigated. The Carberry/AC Cadillac population was genotyped with DArT(®) and simple sequence repeat markers. The parents and population were phenotyped for stripe rust severity and infection response in field rust nurseries in Kenya (Njoro), Canada (Swift Current), and New Zealand (Lincoln); and for leaf rust severity and infection response in field nurseries in Canada (Swift Current) and New Zealand (Lincoln). AC Cadillac was a source of stripe rust resistance QTL on chromosomes 2A, 2B, 3A, 3B, 5B, and 7B; and Carberry was a source of resistance on chromosomes 2B, 4B, and 7A. AC Cadillac contributed QTL for resistance to leaf rust on chromosome 2A and Carberry contributed QTL on chromosomes 2B and 4B. Stripe rust resistance QTL co-localized with previously reported stem rust resistance QTL on 2B, 3B, and 7B, while leaf rust resistance QTL co-localized with 4B stem rust resistance QTL. Several epistatic interactions were identified both for stripe and leaf rust resistance QTL. We have identified useful combinations of genetic loci with main and epistatic effects. Multiple disease resistance regions identified on chromosomes 2A, 2B, 3B, 4B, 5B, and 7B are prime candidates for further investigation and validation of their broad resistance.

Evolution of haploid-diploid life cycles when haploid and diploid fitnesses are not equal.

PubMed

Scott, Michael F; Rescan, Marie

2017-02-01

Many organisms spend a significant portion of their life cycle as haploids and as diploids (a haploid-diploid life cycle). However, the evolutionary processes that could maintain this sort of life cycle are unclear. Most previous models of ploidy evolution have assumed that the fitness effects of new mutations are equal in haploids and homozygous diploids, however, this equivalency is not supported by empirical data. With different mutational effects, the overall (intrinsic) fitness of a haploid would not be equal to that of a diploid after a series of substitution events. Intrinsic fitness differences between haploids and diploids can also arise directly, for example because diploids tend to have larger cell sizes than haploids. Here, we incorporate intrinsic fitness differences into genetic models for the evolution of time spent in the haploid versus diploid phases, in which ploidy affects whether new mutations are masked. Life-cycle evolution can be affected by intrinsic fitness differences between phases, the masking of mutations, or a combination of both. We find parameter ranges where these two selective forces act and show that the balance between them can favor convergence on a haploid-diploid life cycle, which is not observed in the absence of intrinsic fitness differences. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Association of vitamin D receptor gene polymorphisms with diabetic dyslipidemia in the elderly male population in North China.

PubMed

Xia, Zheng; Hu, Yazhuo; Han, Zhitao; Gao, Ya; Bai, Jie; He, Yao; Zhao, Hua; Zhang, Honghong

2017-01-01

The prevalence of dyslipidemia is rising alarmingly in elderly Han Chinese male patients with type 2 diabetes mellitus (T2DM). The genetic factors that contribute to the development of diabetic dyslipidemia remain incompletely identified. This study was conducted to assess the association between vitamin D receptor (VDR) polymorphisms and development of dyslipidemia in the Han elderly male population with T2DM in North China. A total of 242 T2DM patients with dyslipidemia (DH group, n=108) or without dyslipidemia (DO group, n=134) and 100 controls were genotyped for ApaI, TaqI and FokI single nucleotide polymorphisms (SNPs) of the VDR gene using polymerase chain reaction-restriction fragment length polymorphism and sequencing. The frequency and distribution of the SNPs were compared between cases and controls. The distribution of genotypes of VDR-FokI was significantly different between the control and DM group ( P =0.033), as well as between the control and DH subgroup ( P =0.011) but not DO subgroup ( P =0.111). The frequency of C allele and CC genotype of FokI was significantly higher in the DH patients than in the controls ( P =0.015 and P =0.003, respectively). Logistic regression analysis in a dominant model homozygous for the C allele of the FokI SNP showed that CC genotype was associated with DH patients (OR =1.797, 95% CI: 1.077-2.999, P =0.025). Significant associations of the ApaI and TaqI SNPs with either DO or DH subjects were not observed. These findings suggest that CC genotype of VDR-FokI is a risk factor for T2DM patients with dyslipidemia in elderly males in North China.

Artificial parthenogenesis and control of voltinism to manage transgenic populations in Bombyx mori.

PubMed

Grenier, Anne-Marie; Da Rocha, Martine; Jalabert, Audrey; Royer, Corinne; Mauchamp, Bernard; Chavancy, Gérard

2004-08-01

In order to improve the management of transformed populations in a routine application of transgenesis technology in Bombyx mori, we modified its mode of reproduction and its voltinism. On one hand, after a stable integration of the gene of interest by transgenesis, it is preferable to maintain this gene in an identical genomic context through successive generations. This can be obtained by artificial parthenogenetic reproduction (ameiotic parthenogenesis) giving isogenic females identical to their transformed mother. On the other hand, it is essential to obtain continuous generations (polyvoltinism) after microinjection, in order to screen positive transgenic insects and study genetics and insertion of the transgene. Thereafter, it is more convenient to store these populations, as diapause eggs before their use in biotechnology application. We obtained such polyvoltine parthenoclones, first by selection for a parthenogenetic character in polyvoltine races, and second, by selection for a polyvoltine character in a parthenogenetic, but diapausing clone of B. mori. As diapause was directly under the control of diapause hormone (DH), we also tested direct injection of DH in female pupae of polyvoltine strains, as well as anti-DH antibody treatment to eliminate diapause in univoltine strains. We discussed the advantages and limitations of these methods and proved the feasibility in obtaining polyvoltine parthenoclones and determining the voltinism in B. mori. These methods would permit us to improve the management of populations used in transgenesis technology.

Association Between Optic Disc Hemorrhage and Renal Function in South Korea.

PubMed

Lee, Jae Yeun; Kim, Joon Mo; Shim, Seong Hee; Lee, Jin Young; Yoo, Chungkwon; Won, Yu Sam; Hyun, Young Youl; Park, Ki Ho

2018-03-01

The purpose of this article is to investigate the relationship between renal function and disc hemorrhage (DH). This retrospective cross-sectional survey was conducted at Kangbuk Samsung Hospital Health Screening Center between August 2012 and July 2013, and a total of 168,044 participants at least 20 years of age who voluntarily visited the health screening center for systemic and ophthalmologic examinations, including fundus photography, were enrolled. All subjects underwent a physical examination and provided samples for laboratory analysis. Digital fundus photographs of both eyes were taken and reviewed. Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine concentration using the Modification of Diet in Renal Disease (MDRD) formula and Cockcroft-Gault (CG) formula. Subjects were stratified by eGFR into quartiles. Among participants, 220 (0.1%) showed DH, and 2376 (1.6%) showed glaucomatous retinal nerve fiber layer defects. The DH group showed higher creatinine and lower eGFR than the non-DH group. A significant trend was observed among higher creatinine, decreased eGFR as obtained by the MDRD and CG formulas, and the prevalence of DH (P for trend ≤0.003, logistic regression analysis). A multiple logistic regression model adjusted for age, sex, hypertension, diabetes, and hyperlipidemia showed that the lowest eGFR quartiles estimated by MDRD and CG were significantly associated with DH compared with the highest eGFR quartile (adjusted odds ratio, 1.96; 95% confidence interval, 1.22-3.14 by CG, 1.86; 95% confidence interval, 1.17-2.96 by MDRD). Renal function impairment was independently associated with a higher prevalence of DH in a South Korean population.

Incidence and Prevalence of Celiac Disease and Dermatitis Herpetiformis in the UK Over Two Decades: Population-Based Study

PubMed Central

West, Joe; Fleming, Kate M; Tata, Laila J; Card, Timothy R; Crooks, Colin J

2014-01-01

OBJECTIVES: Few studies have quantified the incidence and prevalence of celiac disease (CD) and dermatitis herpetiformis (DH) nationally and regionally by time and age groups. Understanding this epidemiology is crucial for hypothesizing about causes and quantifying the burden of disease. METHODS: Patients with CD or DH were identified in the Clinical Practice Research Datalink between 1990 and 2011. Incidence rates and prevalence were calculated by age, sex, year, and region of residence. Incidence rate ratios (IRR) adjusted for age, sex, and region were calculated with Poisson regression. RESULTS: A total of 9,087 incident cases of CD and 809 incident cases of DH were identified. Between 1990 and 2011, the incidence rate of CD increased from 5.2 per 100,000 (95% confidence interval (CI), 3.8–6.8) to 19.1 per 100,000 person-years (95% CI, 17.8–20.5; IRR, 3.6; 95% CI, 2.7–4.8). The incidence of DH decreased over the same time period from 1.8 per 100,000 to 0.8 per 100,000 person-years (average annual IRR, 0.96; 95% CI, 0.94–0.97). The absolute incidence of CD per 100,000 person-years ranged from 22.3 in Northern Ireland to 10 in London. There were large regional variations in prevalence for CD but not DH. CONCLUSIONS: We found a fourfold increase in the incidence of CD in the United Kingdom over 22 years, with large regional variations in prevalence. This contrasted with a 4% annual decrease in the incidence of DH, with minimal regional variations in prevalence. These contrasts could reflect differences in diagnosis between CD (serological diagnosis and case finding) and DH (symptomatic presentation) or the possibility that diagnosing and treating CD prevents the development of DH. PMID:24667576

Single nucleotide polymorphism (SNP) discovery in rainbow trout using restriction site associated DNA (RAD) sequencing of doubled haploids and assessment of polymorphism in a population survey

USDA-ARS?s Scientific Manuscript database

Background: Our goal is to produce a high-throughput SNP genotyping platform for genomic analyses in rainbow trout that will enable fine mapping of QTL, whole genome association studies, genomic selection for improved aquaculture production traits, and genetic analyses of wild populations that aid ...

Leaf-Mining and Gall-Forming Insects: Tools for Teaching Population Ecology.

ERIC Educational Resources Information Center

Brown, Valerie K.

1984-01-01

Discusses the use of leaf mines (formed by larvae of small moths or flies) and galls (wasps' larvae) in various insect population studies. Also considers the advantages of using these structures for instructional purposes. (DH)

Circuitry and plasticity of the dorsal horn--toward a better understanding of neuropathic pain.

PubMed

West, S J; Bannister, K; Dickenson, A H; Bennett, D L

2015-08-06

Maladaptive plasticity within the dorsal horn (DH) of the spinal cord is a key substrate for development of neuropathic pain following peripheral nerve injury. Advances in genetic engineering, tracing techniques and opto-genetics are leading to a much better understanding of the complex circuitry of the spinal DH and the radical changes evoked in such circuitry by nerve injury. These changes can be viewed at multiple levels including: synaptic remodeling including enhanced excitatory and reduced inhibitory drive, morphological and electrophysiological changes which are observed both to primary afferent inputs as well as DH neurons, and ultimately circuit-level rewiring which leads to altered connectivity and aberrant processing of sensory inputs in the DH. The DH should not be seen in isolation but is subject to important descending modulation from the brainstem, which is further dysregulated by nerve injury. Understanding which changes relate to specific disease-states is essential, and recent work has aimed to stratify patient populations in a mechanistic fashion. In this review we will discuss how such pathophysiological mechanisms may lead to the distressing sensory phenomena experienced by patients suffering neuropathic pain, and the relationship of such mechanisms to current and potential future treatment modalities. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Homozygote Depression in Gamete-Derived Dragon-Fruit (Hylocereus) Lines

PubMed Central

Li, Daqing; Arroyave Martinez, Maria F.; Shaked, Ruth; Tel-Zur, Noemi

2018-01-01

Putative gamete-derived progenies from two Hylocereus species, the diploid H. monacanthus and the tetraploid H. megalanthus, were studied with the dual aims to confirm their gamete origin and to evaluate their potential use as genetic resources. An additional goal was to determine the origin (allotetraploid vs. autotetraploid) of H. megalanthus by exploring morphological variations in the di-haploid (2x) H. megalanthus progeny. Gamete origin was proved in all five H. monacanthus lines obtained and in 49 of the 70 H. megalanthus lines by using flow cytometry and simple sequence repeat (SSR) markers. The five double-haploid (2x) H. monacanthus lines showed low vigor and abnormal flower development, with malformed ovules and aborted pollen grains. Only one flower set fruit, giving several viable seeds. For H. megalanthus, both abnormal ovules and defective anthers were observed in the di-haploid (2x) and double di-haploid (4x) lines. Among the 46 di-haploid lines, only 14 set fruit. Another 13 di-haploid lines formed flower buds that abscised before anthesis or soon after pollination. The severe sterility of the double-haploid H. monacanthus and the reduced fertility of all the di-haploid and double di-haploid H. megalanthus lines can be linked to their reduced heterozygosity, which drastically affected the development of normal female and male organs. We thus concluded that chromosome doubling, as occurred spontaneously in the double-haploid H. monacanthus and the double di-haploid H. megalanthus, is not sufficient to restore fertility in Hylocereus. We also observed very low gametoclonal variation among the di-haploid (2x) H. megalanthus lines, a finding that supported an autotetraploid, rather than an allotetraploid, origin of this species. Nonetheless, despite the above-described challenging limitations, these gamete-derived lines are currently being bred as the seed parent, offering unique possibilities for genetic research and additional breeding. PMID:29354138

Dramatic improvement in genome assembly achieved using doubled-haploid genomes.

PubMed

Zhang, Hong; Tan, Engkong; Suzuki, Yutaka; Hirose, Yusuke; Kinoshita, Shigeharu; Okano, Hideyuki; Kudoh, Jun; Shimizu, Atsushi; Saito, Kazuyoshi; Watabe, Shugo; Asakawa, Shuichi

2014-10-27

Improvement in de novo assembly of large genomes is still to be desired. Here, we improved draft genome sequence quality by employing doubled-haploid individuals. We sequenced wildtype and doubled-haploid Takifugu rubripes genomes, under the same conditions, using the Illumina platform and assembled contigs with SOAPdenovo2. We observed 5.4-fold and 2.6-fold improvement in the sizes of the N50 contig and scaffold of doubled-haploid individuals, respectively, compared to the wildtype, indicating that the use of a doubled-haploid genome aids in accurate genome analysis.

Desulfurization of 2-thiouracil nucleosides: conformational studies of 4-pyrimidinone nucleosides.

PubMed

Kraszewska, Karina; Kaczyńska, Iwona; Jankowski, Stefan; Karolak-Wojciechowska, Janina; Sochacka, Elzbieta

2011-04-01

4-Pyrimidinone ribofuranoside (H(2)o(4)U) and 4-pyrimidinone 2'-deoxyribofuranoside (dH(2)o(4)U) were synthesized by the oxidative desulfurization of parent 2-thiouracil nucleosides with m-chloroperbenzoic acid. The crystal structures of H(2)o(4)U and dH(2)o(4)U and their conformations in solution were determined and compared with corresponding 2-thiouracil and uracil nucleosides. The absence of a large 2-thiocarbonyl/2-carbonyl group in the nucleobase moiety results in C2'-endo puckering of the ribofuranose ring (S conformer) in the crystal structure of H(2)o(4)U, which is not typical of RNA nucleosides. Interestingly, the hydrogen bonding network in the crystals of dH(2)o(4)U stabilizes the sugar moiety conformation in the C3'-endo form (N conformer), rarely found in DNA nucleosides. In aqueous solution, dH(2)o(4)U reveals a similar population of the C2'-endo conformation (65%) to that of 2'-deoxy-2-thiouridine (62%), while the 62% population of the S conformer for H(2)o(4)U is significantly different from that of the parent 2-thiouridine, for which the N conformer is dominant (71%). Such a difference may be of biological importance, as the desulfurization process of natural tRNA 2-thiouridines may occur under conditions of oxidative stress in the cell and may influence the decoding process. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dynamic properties in the four-state haploid coupled discrete-time mutation-selection model with an infinite population limit

NASA Astrophysics Data System (ADS)

Lee, Kyu Sang; Gill, Wonpyong

2017-11-01

The dynamic properties, such as the crossing time and time-dependence of the relative density of the four-state haploid coupled discrete-time mutation-selection model, were calculated with the assumption that μ ij = μ ji , where μ ij denotes the mutation rate between the sequence elements, i and j. The crossing time for s = 0 and r 23 = r 42 = 1 in the four-state model became saturated at a large fitness parameter when r 12 > 1, was scaled as a power law in the fitness parameter when r 12 = 1, and diverged when the fitness parameter approached the critical fitness parameter when r 12 < 1, where r ij = μ ij / μ 14.

Dissection of expression-quantitative trait locus and allele specificity using a haploid/diploid plant system - insights into compensatory evolution of transcriptional regulation within populations.

PubMed

Verta, Jukka-Pekka; Landry, Christian R; MacKay, John

2016-07-01

Regulation of gene expression plays a central role in translating genotypic variation into phenotypic variation. Dissection of the genetic basis of expression variation is key to understanding how expression regulation evolves. Such analyses remain challenging in contexts where organisms are outbreeding, highly heterozygous and long-lived such as in the case of conifer trees. We developed an RNA sequencing (RNA-seq)-based approach for both expression-quantitative trait locus (eQTL) mapping and the detection of cis-acting (allele-specific) vs trans-acting (non-allele-specific) eQTLs. This method can be potentially applied to many conifers. We used haploid and diploid meiotic seed tissues of a single self-fertilized white spruce (Picea glauca) individual to dissect eQTLs according to linkage and allele specificity. The genetic architecture of local eQTLs linked to the expressed genes was particularly complex, consisting of cis-acting, trans-acting and, surprisingly, compensatory cis-trans effects. These compensatory effects influence expression in opposite directions and are neutral when combined in homozygotes. Nearly half of local eQTLs were under compensation, indicating that close linkage between compensatory cis-trans factors is common in spruce. Compensated genes were overrepresented in developmental and cell organization functions. Our haploid-diploid eQTL analysis in spruce revealed that compensatory cis-trans eQTLs segregate within populations and evolve in close genetic linkage. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

How Dense!

ERIC Educational Resources Information Center

Codner, A. C.

1985-01-01

Suggests examining population density to help students understand density as a chemical concept. Simple experiments and demonstrations with carbon dioxide, burning oil, natural gas, and temperature are also suggested. (DH)

Mutator dynamics in sexual and asexual experimental populations of yeast.

PubMed

Raynes, Yevgeniy; Gazzara, Matthew R; Sniegowski, Paul D

2011-06-07

In asexual populations, mutators may be expected to hitchhike with associated beneficial mutations. In sexual populations, recombination is predicted to erode such associations, inhibiting mutator hitchhiking. To investigate the effect of recombination on mutators experimentally, we compared the frequency dynamics of a mutator allele (msh2Δ) in sexual and asexual populations of Saccharomyces cerevisiae. Mutator strains increased in frequency at the expense of wild-type strains in all asexual diploid populations, with some approaching fixation in 150 generations of propagation. Over the same period of time, mutators declined toward loss in all corresponding sexual diploid populations as well as in haploid populations propagated asexually. We report the first experimental investigation of mutator dynamics in sexual populations. We show that a strong mutator quickly declines in sexual populations while hitchhiking to high frequency in asexual diploid populations, as predicted by theory. We also show that the msh2Δ mutator has a high and immediate realized cost that is alone sufficient to explain its decline in sexual populations. We postulate that this cost is indirect; namely, that it is due to a very high rate of recessive lethal or strongly deleterious mutation. However, we cannot rule out the possibility that msh2Δ also has unknown directly deleterious effects on fitness, and that these effects may differ between haploid asexual and sexual populations. Despite these reservations, our results prompt us to speculate that the short-term cost of highly deleterious recessive mutations can be as important as recombination in preventing mutator hitchhiking in sexual populations.

Common sex-linked deleterious alleles in a plant parasitic fungus alter infection success but show no pleiotropic advantage.

PubMed

Giraud, T; Jonot, O; Shykoff, J A

2006-05-01

Microbotryum violaceum is a fungus that causes the sterilizing anther smut disease in Caryophyllaceae. Its diploid teliospores normally produce equal proportions of haploid sporidia of its two mating types. However natural populations contain high frequencies of individuals producing sporidia of only one mating type ('biased strains'). This mating type-ratio bias is caused by deleterious alleles at haploid phase ('haplo-lethals') linked to the mating type locus that can be transmitted only by intra-tetrad selfing. We used experimental inoculations to test some of the hypotheses proposed to explain the maintenance of haplo-lethals. We found a disadvantage of biased strains in infection ability and high intra-tetrad mating rates. Biased strains had no higher competitive ability nor shorter latency and their higher spore production per flower appeared insufficient to compensate their disadvantages. These findings were only consistent with the hypothesis that haplo-lethals are maintained under a metapopulation structure because of high intra-tetrad selfing rates, founder effects and selection at the population level.

Quantitative trait loci for resistance to stripe rust of wheat revealed using global field nurseries and opportunities for stacking resistance genes.

PubMed

Bokore, Firdissa E; Cuthbert, Richard D; Knox, Ron E; Randhawa, Harpinder S; Hiebert, Colin W; DePauw, Ron M; Singh, Asheesh K; Singh, Arti; Sharpe, Andrew G; N'Diaye, Amidou; Pozniak, Curtis J; McCartney, Curt; Ruan, Yuefeng; Berraies, Samia; Meyer, Brad; Munro, Catherine; Hay, Andy; Ammar, Karim; Huerta-Espino, Julio; Bhavani, Sridhar

2017-12-01

Quantitative trait loci controlling stripe rust resistance were identified in adapted Canadian spring wheat cultivars providing opportunity for breeders to stack loci using marker-assisted breeding. Stripe rust or yellow rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss., is a devastating disease of common wheat (Triticum aestivum L.) in many regions of the world. The objectives of this research were to identify and map quantitative trait loci (QTL) associated with stripe rust resistance in adapted Canadian spring wheat cultivars that are effective globally, and investigate opportunities for stacking resistance. Doubled haploid (DH) populations from the crosses Vesper/Lillian, Vesper/Stettler, Carberry/Vesper, Stettler/Red Fife and Carberry/AC Cadillac were phenotyped for stripe rust severity and infection response in field nurseries in Canada (Lethbridge and Swift Current), New Zealand (Lincoln), Mexico (Toluca) and Kenya (Njoro), and genotyped with SNP markers. Six QTL for stripe rust resistance in the population of Vesper/Lillian, five in Vesper/Stettler, seven in Stettler/Red Fife, four in Carberry/Vesper and nine in Carberry/AC Cadillac were identified. Lillian contributed stripe rust resistance QTL on chromosomes 4B, 5A, 6B and 7D, AC Cadillac on 2A, 2B, 3B and 5B, Carberry on 1A, 1B, 4A, 4B, 7A and 7D, Stettler on 1A, 2A, 3D, 4A, 5B and 6A, Red Fife on 2D, 3B and 4B, and Vesper on 1B, 2B and 7A. QTL on 1A, 1B, 2A, 2B, 3B, 4A, 4B, 5B, 7A and 7D were observed in multiple parents. The populations are compelling sources of recombination of many stripe rust resistance QTL for stacking disease resistance. Gene pyramiding should be possible with little chance of linkage drag of detrimental genes as the source parents were mostly adapted cultivars widely grown in Canada.

Incomplete development of the spleen and the deformity in the chimeras between asplenic mutant (Dominant hemimelia) and normal mice.

PubMed

Suto, J; Wakayama, T; Imamura, K; Goto, S; Fukuta, K

1995-08-01

The semidominant gene Dh (Dominant hemimelia) induces skeletal and visceral abnormalities of various degrees and failure of the spleen in mice. The homozygous individual (Dh/Dh) seems to be lethal. The present experiment was designed to investigate the ability Dh cells to form a spleen and the genesis of the hind limb malformations by Dh/Dh and Dh/+ cells in chimeric mice. The Dh/Dh and Dh/+ embryos were produced in the F2 progeny of a cross between inbred strains of Dh/+ and DDD mice. They were aggregated with C3H/He or C57BL/6 embryos to make chimeras. Identification of Dh/Dh or Dh/+ embryos was carried out by Pep-3, and chimerism was analyzed by Gpi-1. Of 25 chimeras carrying the Dh gene, four mice formed a small spleen, two mice had a vestigial spleen, and the others no spleen. The tissues of the incompletely developed spleens were normal histologically and Dh cells were involved in the tissues of the spleen. In the chimeric mice, hindlimb malformation by the Dh gene was reduced in severity and the lethality of the homozygote (Dh/Dh) was rescued.

Comparative Ploidy Proteomics of Candida albicans Biofilms Unraveled the Role of the AHP1 Gene in the Biofilm Persistence Against Amphotericin B*

PubMed Central

Zeng, Guisheng; Qingsong, Lin; Kwang, Lim Teck; Tong, Cao; Chan, Fong Yee; Wang, Yue; Seneviratne, Chaminda Jayampath

2016-01-01

Candida albicans is a major fungal pathogen causing lethal infections in immunocompromised patients. C. albicans forms antifungal tolerant biofilms contributing significantly to therapeutic failure. The recently established haploid C. albicans biofilm model provides a new toolbox to uncover the mechanism governing the higher antifungal tolerance of biofilms. Here, we comprehensively examined the proteomics and antifungal susceptibility of standard diploid (SC5314 and BWP17) and stable haploid (GZY792 and GZY803) strains of C. albicans biofilms. Subsequent downstream analyses identified alkyl hydroperoxide reductase 1 (AHP1) as a critical determinant of C. albicans biofilm's tolerance of amphotericin B. At 32 μg/ml of amphotericin B, GZY803 haploid biofilms showed 0.1% of persister population as compared with 1% of the diploid biofilms. AHP1 expression was found to be lower in GZY803 biofilms, and AHP1 overexpression in GZY803 restored the percentage of persister population. Consistently, deleting AHP1 in the diploid strain BWP17 caused a similar increase in amphotericin B susceptibility. AHP1 expression was also positively correlated with the antioxidant potential. Furthermore, C. albicans ira2Δ/Δ biofilms were susceptible to amphotericin B and had a diminished antioxidant capacity. Interestingly, AHP1 overexpression in the ira2Δ/Δ strain restored the antioxidant potential and enhanced the persister population against amphotericin B, and shutting down the AHP1 expression in ira2Δ/Δ biofilms reversed the effect. In conclusion, we provide evidence that the AHP1 gene critically determines the amphotericin B tolerance of C. albicans biofilms possibly by maintaining the persisters' antioxidant capacity. This finding will open up new avenues for developing therapies targeting the persister population of C. albicans biofilms. The mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD004274. PMID:27644984

Comparative Ploidy Proteomics of Candida albicans Biofilms Unraveled the Role of the AHP1 Gene in the Biofilm Persistence Against Amphotericin B.

PubMed

Truong, Thuyen; Zeng, Guisheng; Qingsong, Lin; Kwang, Lim Teck; Tong, Cao; Chan, Fong Yee; Wang, Yue; Seneviratne, Chaminda Jayampath

2016-11-01

Candida albicans is a major fungal pathogen causing lethal infections in immunocompromised patients. C. albicans forms antifungal tolerant biofilms contributing significantly to therapeutic failure. The recently established haploid C. albicans biofilm model provides a new toolbox to uncover the mechanism governing the higher antifungal tolerance of biofilms. Here, we comprehensively examined the proteomics and antifungal susceptibility of standard diploid (SC5314 and BWP17) and stable haploid (GZY792 and GZY803) strains of C. albicans biofilms. Subsequent downstream analyses identified alkyl hydroperoxide reductase 1 (AHP1) as a critical determinant of C. albicans biofilm's tolerance of amphotericin B. At 32 μg/ml of amphotericin B, GZY803 haploid biofilms showed 0.1% of persister population as compared with 1% of the diploid biofilms. AHP1 expression was found to be lower in GZY803 biofilms, and AHP1 overexpression in GZY803 restored the percentage of persister population. Consistently, deleting AHP1 in the diploid strain BWP17 caused a similar increase in amphotericin B susceptibility. AHP1 expression was also positively correlated with the antioxidant potential. Furthermore, C. albicans ira2Δ/Δ biofilms were susceptible to amphotericin B and had a diminished antioxidant capacity. Interestingly, AHP1 overexpression in the ira2Δ/Δ strain restored the antioxidant potential and enhanced the persister population against amphotericin B, and shutting down the AHP1 expression in ira2Δ/Δ biofilms reversed the effect. In conclusion, we provide evidence that the AHP1 gene critically determines the amphotericin B tolerance of C. albicans biofilms possibly by maintaining the persisters' antioxidant capacity. This finding will open up new avenues for developing therapies targeting the persister population of C. albicans biofilms. The mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD004274. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

A High-Density Genetic Map Identifies a Novel Major QTL for Boron Efficiency in Oilseed Rape (Brassica napus L.)

PubMed Central

Wang, Xiaohua; Zhao, Hua; Shi, Lei; Xu, Fangsen

2014-01-01

Low boron (B) seriously limits the growth of oilseed rape (Brassica napus L.), a high B demand species that is sensitive to low B conditions. Significant genotypic variations in response to B deficiency have been observed among B. napus cultivars. To reveal the genetic basis for B efficiency in B. napus, quantitative trait loci (QTLs) for the plant growth traits, B uptake traits and the B efficiency coefficient (BEC) were analyzed using a doubled haploid (DH) population derived from a cross between a B-efficient parent, Qingyou 10, and a B-inefficient parent, Westar 10. A high-density genetic map was constructed based on single nucleotide polymorphisms (SNPs) assayed using Brassica 60 K Infinium BeadChip Array, simple sequence repeats (SSRs) and amplified fragment length polymorphisms (AFLPs). The linkage map covered a total length of 2139.5 cM, with 19 linkage groups (LGs) and an average distance of 1.6 cM between adjacent markers. Based on hydroponic evaluation of six B efficiency traits measured in three separate repeated trials, a total of 52 QTLs were identified, accounting for 6.14–46.27% of the phenotypic variation. A major QTL for BEC, qBEC-A3a, was co-located on A3 with other QTLs for plant growth and B uptake traits under low B stress. Using a subset of substitution lines, qBEC-A3a was validated and narrowed down to the interval between CNU384 and BnGMS436. The results of this study provide a novel major locus located on A3 for B efficiency in B. napus that will be suitable for fine mapping and marker-assisted selection breeding for B efficiency in B. napus. PMID:25375356

Yield-trait performance landscapes: from theory to application in breeding maize for drought tolerance.

PubMed

Messina, Carlos D; Podlich, Dean; Dong, Zhanshan; Samples, Mitch; Cooper, Mark

2011-01-01

The effectiveness of breeding strategies to increase drought resistance in crops could be increased further if some of the complexities in gene-to-phenotype (G → P) relations associated with epistasis, pleiotropy, and genotype-by-environment interactions could be captured in realistic G → P models, and represented in a quantitative manner useful for selection. This paper outlines a promising methodology. First, the concept of landscapes was extended from the study of fitness landscapes used in evolutionary genetics to the characterization of yield-trait-performance landscapes for agricultural environments and applications in plant breeding. Second, the E(NK) model of trait genetic architecture was extended to incorporate biophysical, physiological, and statistical components. Third, a graphical representation is proposed to visualize the yield-trait performance landscape concept for use in selection decisions. The methodology was demonstrated at a particular stage of a maize breeding programme with the objective of improving the drought tolerance of maize hybrids for the US Western Corn-Belt. The application of the framework to the genetic improvement of drought tolerance in maize supported selection of Doubled Haploid (DH) lines with improved levels of drought tolerance based on physiological genetic knowledge, prediction of test-cross yield within the target population of environments, and their predicted potential to sustain further genetic progress with additional cycles of selection. The existence of rugged yield-performance landscapes with multiple peaks and intervening valleys of lower performance, as shown in this study, supports the proposition that phenotyping strategies, and the directions emphasized in genomic selection can be improved by creating knowledge of the topology of yield-trait performance landscapes.

Transcriptome analysis of functional differentiation between haploid and diploid cells of Emiliania huxleyi, a globally significant photosynthetic calcifying cell.

PubMed

von Dassow, Peter; Ogata, Hiroyuki; Probert, Ian; Wincker, Patrick; Da Silva, Corinne; Audic, Stéphane; Claverie, Jean-Michel; de Vargas, Colomban

2009-01-01

Eukaryotes are classified as either haplontic, diplontic, or haplo-diplontic, depending on which ploidy levels undergo mitotic cell division in the life cycle. Emiliania huxleyi is one of the most abundant phytoplankton species in the ocean, playing an important role in global carbon fluxes, and represents haptophytes, an enigmatic group of unicellular organisms that diverged early in eukaryotic evolution. This species is haplo-diplontic. Little is known about the haploid cells, but they have been hypothesized to allow persistence of the species between the yearly blooms of diploid cells. We sequenced over 38,000 expressed sequence tags from haploid and diploid E. huxleyi normalized cDNA libraries to identify genes involved in important processes specific to each life phase (2N calcification or 1N motility), and to better understand the haploid phase of this prominent haplo-diplontic organism. The haploid and diploid transcriptomes showed a dramatic differentiation, with approximately 20% greater transcriptome richness in diploid cells than in haploid cells and only

Transcriptome analysis of functional differentiation between haploid and diploid cells of Emiliania huxleyi, a globally significant photosynthetic calcifying cell

PubMed Central

2009-01-01

Background Eukaryotes are classified as either haplontic, diplontic, or haplo-diplontic, depending on which ploidy levels undergo mitotic cell division in the life cycle. Emiliania huxleyi is one of the most abundant phytoplankton species in the ocean, playing an important role in global carbon fluxes, and represents haptophytes, an enigmatic group of unicellular organisms that diverged early in eukaryotic evolution. This species is haplo-diplontic. Little is known about the haploid cells, but they have been hypothesized to allow persistence of the species between the yearly blooms of diploid cells. We sequenced over 38,000 expressed sequence tags from haploid and diploid E. huxleyi normalized cDNA libraries to identify genes involved in important processes specific to each life phase (2N calcification or 1N motility), and to better understand the haploid phase of this prominent haplo-diplontic organism. Results The haploid and diploid transcriptomes showed a dramatic differentiation, with approximately 20% greater transcriptome richness in diploid cells than in haploid cells and only ≤ 50% of transcripts estimated to be common between the two phases. The major functional category of transcripts differentiating haploids included signal transduction and motility genes. Diploid-specific transcripts included Ca2+, H+, and HCO3- pumps. Potential factors differentiating the transcriptomes included haploid-specific Myb transcription factor homologs and an unusual diploid-specific histone H4 homolog. Conclusions This study permitted the identification of genes likely involved in diploid-specific biomineralization, haploid-specific motility, and transcriptional control. Greater transcriptome richness in diploid cells suggests they may be more versatile for exploiting a diversity of rich environments whereas haploid cells are intrinsically more streamlined. PMID:19832986

Association of dentine hypersensitivity with different risk factors - a cross sectional study.

PubMed

Vijaya, V; Sanjay, Venkataraam; Varghese, Rana K; Ravuri, Rajyalakshmi; Agarwal, Anil

2013-12-01

This study was done to assess the prevalence of Dentine hypersensitivity (DH) and its associated risk factors. This epidemiological study was done among patients coming to dental college regarding prevalence of DH. A self structured questionnaire along with clinical examination was done for assessment. Descriptive statistics were obtained and frequency distribution was calculated using Chi square test at p value <0.05. Stepwise multiple linear regression was also done to access frequency of DH with different factors. The study population was comprised of 655 participants with different age groups. Our study showed prevalence as 55% and it was more common among males. Similarly smokers and those who use hard tooth brush had more cases of DH. Step wise multiple linear regression showed that best predictor for DH was age followed by habit of smoking and type of tooth brush. Most aggravating factors were cold water (15.4%) and sweet foods (14.7%), whereas only 5% of the patients had it while brushing. A high level of dental hypersensitivity has been in this study and more common among males. A linear finding was shown with age, smoking and type of tooth brush. How to cite this article: Vijaya V, Sanjay V, Varghese RK, Ravuri R, Agarwal A. Association of Dentine Hypersensitivity with Different Risk Factors - A Cross Sectional Study. J Int Oral Health 2013;5(6):88-92 .

Clinical development of new prophylactic antimalarial drugs after the 5th Amendment to the Declaration of Helsinki

PubMed Central

Dow, Geoffrey S; Magill, Alan J; Ohrt, Colin

2008-01-01

Malaria is of continuing concern in nonimmune traveling populations. Traditionally, antimalarial drugs have been developed as agents for dual indications (treatment and prophylaxis). However, since 2000, when the 5th Amendment to the Declaration of Helsinki (DH2000) was adopted, development of new malaria prophylaxis drugs in this manner has ceased. As a consequence, there may not be any new drugs licensed for this indication in the foreseeable future. Major pharmaceutical companies have interpreted DH2000 to mean that the traditional development paradigm may be considered unethical because of doubt over the likelihood of benefit to endemic populations participating in clinical studies, the use of placebo, and the sustainability of post-trial access to study medications. In this article, we explore the basis of these concerns and suggest that the traditional development paradigm remains ethical under certain circumstances. We also consider alternative approaches that may be more attractive to sponsors as they either do not use placebo, or utilize populations in endemic countries who may unambiguously benefit. These approaches represent the way forward in the future, but are at present unproven in clinical practice, and face numerous regulatory, logistical and technical challenges. Consequently, in the short term, we argue that the traditional clinical development paradigm remains the most feasible approach and is ethical and consistent with the spirit of DH2000 under the appropriate circumstances. PMID:19209263

Fully-Automated High-Throughput NMR System for Screening of Haploid Kernels of Maize (Corn) by Measurement of Oil Content

PubMed Central

Xu, Xiaoping; Huang, Qingming; Chen, Shanshan; Yang, Peiqiang; Chen, Shaojiang; Song, Yiqiao

2016-01-01

One of the modern crop breeding techniques uses doubled haploid plants that contain an identical pair of chromosomes in order to accelerate the breeding process. Rapid haploid identification method is critical for large-scale selections of double haploids. The conventional methods based on the color of the endosperm and embryo seeds are slow, manual and prone to error. On the other hand, there exists a significant difference between diploid and haploid seeds generated by high oil inducer, which makes it possible to use oil content to identify the haploid. This paper describes a fully-automated high-throughput NMR screening system for maize haploid kernel identification. The system is comprised of a sampler unit to select a single kernel to feed for measurement of NMR and weight, and a kernel sorter to distribute the kernel according to the measurement result. Tests of the system show a consistent accuracy of 94% with an average screening time of 4 seconds per kernel. Field test result is described and the directions for future improvement are discussed. PMID:27454427

A GA-insensitive dwarf mutant of Brassica napus L. correlated with mutation in pyrimidine box in the promoter of GID1.

PubMed

Li, Huapeng; Wang, Yun; Li, Xiaocheng; Gao, Yong; Wang, Zhijun; Zhao, Yun; Wang, Maolin

2011-01-01

A dwarf mutant from Brassica napus, namely NDF-1, which was derived from a high doubled haploid (DH) line '3529'(Brassica napus L.) of which seeds were jointly treated with chemical inducers and fast neutron bombardment, was revealed that dwarfism is under the control of a major gene(designated as ndf1) with a mainly additive effect and non-significant dominance effect. The germination and hypocotyls elongation response of dwarf mutants after exogenous GA and uniconazol application showed NDF-1 was a gibberellin insensitive dwarf. We cloned the Brassica napus GID1 gene, named BnGID1, and found it was the ortholog of AtGID1a. The sequence blasting of the BnGID1 genes from NDF-1 and wild type showed there was no mutant in the gene. But the quantitative RT-PCR analysis of GID1 EST pointed out the mutation was caused by the low-level expression of BnGID1 gene. After sequenced the BnGID1 gene's upstream, we found three bases mutated in the pyrimidine box (P-box) of the BnGID1 promoter, which is linkage with the dwarf mutant.

Selection of transformation-efficient barley genotypes based on TFA (transformation amenability) haplotype and higher resolution mapping of the TFA loci.

PubMed

Hisano, Hiroshi; Meints, Brigid; Moscou, Matthew J; Cistue, Luis; Echávarri, Begoña; Sato, Kazuhiro; Hayes, Patrick M

2017-04-01

The genetic substitution of transformation amenability alleles from 'Golden Promise' can facilitate the development of transformation-efficient lines from recalcitrant barley cultivars. Barley (Hordeum vulgare) cv. 'Golden Promise' is one of the most useful and well-studied cultivars for genetic manipulation. In a previous report, we identified several transformation amenability (TFA) loci responsible for Agrobacterium-mediated transformation using the F 2 generation of immature embryos, derived from 'Haruna Nijo' × 'Golden Promise,' as explants. In this report, we describe higher density mapping of these TFA regions with additional SNP markers using the same transgenic plants. To demonstrate the robustness of transformability alleles at the TFA loci, we genotyped 202 doubled haploid progeny from the cross 'Golden Promise' × 'Full Pint.' Based on SNP genotype, we selected lines having 'Golden Promise' alleles at TFA loci and used them for transformation. Of the successfully transformed lines, DH120366 came the closest to achieving a level of transformation efficiency comparable to 'Golden Promise.' The results validate that the genetic substitution of TFA alleles from 'Golden Promise' can facilitate the development of transformation-efficient lines from recalcitrant barley cultivars.

Production of haploids from anther culture of banana [Musa balbisiana (BB)].

PubMed

Assani, A; Bakry, F; Kerbellec, F; Haïcour, R; Wenzel, G; Foroughi-Wehr, B

2003-02-01

We report here, for the first time, the production of haploid plants of banana Musa balbisiana (BB). Callus was induced from anthers in which the majority of the microspores were at the uninucleate stage. The frequency of callus induction was 77%. Callus proliferation usually preceded embryo formation. About 8% of the anthers developed androgenic embryos. Of the 147 plantlets obtained, 41 were haploids (n=x=11). The frequency of haploid production depended on genotypes used: 18 haploid plants were produced from genotype Pisang klutuk, 12 from Pisang batu, seven from Pisang klutuk wulung and four from Tani. The frequency of regeneration was 1.1%, which was based on the total number of anthers cultured. Diploid plants (2n=2x=22) were also observed in the regenerated plants. The haploid banana plants that were developed will be important material for the improvement of banana through breeding programmes.

Doubled haploid production in Flax (Linum usitatissimum L.).

PubMed

Obert, Bohus; Zácková, Zuzana; Samaj, Jozef; Pretová, Anna

2009-01-01

There is a requirement of haploid and double haploid material and homozygous lines for cell culture studies and breeding in flax. Anther culture is currently the most successful method producing doubled haploid lines in flax. Recently, ovary culture was also described as a good source of doubled haploids. In this review we focus on tissue and plants regeneration using anther culture, and cultivation of ovaries containing unfertilized ovules. The effect of genotype, physiological status of donor plants, donor material pre-treatment and cultivation conditions for flax anthers and ovaries is discussed here. The process of plant regeneration from anther and ovary derived calli is also in the focus of this review. Attention is paid to the ploidy level of regenerated tissue and to the use of molecular markers for determining of gametic origin of flax plants derived from anther and ovary cultures. Finally, some future prospects on the use of doubled haploids in flax biotechnology are outlined here.

The role of somatic recombination in natural populations of the root pathogen Armillaria mellea

USDA-ARS?s Scientific Manuscript database

Fungi have evolved various mechanisms of shuffling genetic material, which can occur in the absence of fruiting and meiosis. In the homobasidiomycete Armillaria (causal agent of Armillaria root disease), the predominant vegetative stage is diploid. Diploid and haploid mycelia can fuse and undergo ka...

Development and Implementation of High-Throughput SNP Genotyping in Barley

USDA-ARS?s Scientific Manuscript database

Approximately 22,000 SNPs were identified from barley ESTs and sequenced amplicons; 4,596 of them were tested for performance in three pilot phase Illumina GoldenGate assays. Pilot phase data from three barley doubled haploid mapping populations supported the production of an initial consensus map, ...

The "Cheshire Cat" escape strategy of the coccolithophore Emiliania huxleyi in response to viral infection.

PubMed

Frada, Miguel; Probert, Ian; Allen, Michael J; Wilson, William H; de Vargas, Colomban

2008-10-14

The coccolithophore Emiliania huxleyi is one of the most successful eukaryotes in modern oceans. The two phases in its haplodiploid life cycle exhibit radically different phenotypes. The diploid calcified phase forms extensive blooms, which profoundly impact global biogeochemical equilibria. By contrast, the ecological role of the noncalcified haploid phase has been completely overlooked. Giant phycodnaviruses (Emiliania huxleyi viruses, EhVs) have been shown to infect and lyse diploid-phase cells and to be heavily implicated in the regulation of populations and the termination of blooms. Here, we demonstrate that the haploid phase of E. huxleyi is unrecognizable and therefore resistant to EhVs that kill the diploid phase. We further show that exposure of diploid E. huxleyi to EhVs induces transition to the haploid phase. Thus we have clearly demonstrated a drastic difference in viral susceptibility between life cycle stages with different ploidy levels in a unicellular eukaryote. Resistance of the haploid phase of E. huxleyi provides an escape mechanism that involves separation of meiosis from sexual fusion in time, thus ensuring that genes of dominant diploid clones are passed on to the next generation in a virus-free environment. These "Cheshire Cat" ecological dynamics release host evolution from pathogen pressure and thus can be seen as an opposite force to a classic "Red Queen" coevolutionary arms race. In E. huxleyi, this phenomenon can account for the fact that the selective balance is tilted toward the boom-and-bust scenario of optimization of both growth rates of calcifying E. huxleyi cells and infectivity of EhVs.

The “Cheshire Cat” escape strategy of the coccolithophore Emiliania huxleyi in response to viral infection

PubMed Central

Frada, Miguel; Probert, Ian; Allen, Michael J.; Wilson, William H.; de Vargas, Colomban

2008-01-01

The coccolithophore Emiliania huxleyi is one of the most successful eukaryotes in modern oceans. The two phases in its haplodiploid life cycle exhibit radically different phenotypes. The diploid calcified phase forms extensive blooms, which profoundly impact global biogeochemical equilibria. By contrast, the ecological role of the noncalcified haploid phase has been completely overlooked. Giant phycodnaviruses (Emiliania huxleyi viruses, EhVs) have been shown to infect and lyse diploid-phase cells and to be heavily implicated in the regulation of populations and the termination of blooms. Here, we demonstrate that the haploid phase of E. huxleyi is unrecognizable and therefore resistant to EhVs that kill the diploid phase. We further show that exposure of diploid E. huxleyi to EhVs induces transition to the haploid phase. Thus we have clearly demonstrated a drastic difference in viral susceptibility between life cycle stages with different ploidy levels in a unicellular eukaryote. Resistance of the haploid phase of E. huxleyi provides an escape mechanism that involves separation of meiosis from sexual fusion in time, thus ensuring that genes of dominant diploid clones are passed on to the next generation in a virus-free environment. These “Cheshire Cat” ecological dynamics release host evolution from pathogen pressure and thus can be seen as an opposite force to a classic “Red Queen” coevolutionary arms race. In E. huxleyi, this phenomenon can account for the fact that the selective balance is tilted toward the boom-and-bust scenario of optimization of both growth rates of calcifying E. huxleyi cells and infectivity of EhVs. PMID:18824682

Eliminating expression of erucic acid-encoding loci allows the identification of "hidden" QTL contributing to oil quality fractions and oil content in Brassica juncea (Indian mustard).

PubMed

Jagannath, Arun; Sodhi, Yashpal Singh; Gupta, Vibha; Mukhopadhyay, Arundhati; Arumugam, Neelakantan; Singh, Indira; Rohatgi, Soma; Burma, Pradeep Kumar; Pradhan, Akshay Kumar; Pental, Deepak

2011-04-01

Oil content and oil quality fractions (viz., oleic, linoleic and linolenic acid) are strongly influenced by the erucic acid pathway in oilseed Brassicas. Low levels of erucic acid in seed oil increases oleic acid content to nutritionally desirable levels, but also increases the linoleic and linolenic acid fractions and reduces oil content in Indian mustard (Brassica juncea). Analysis of phenotypic variability for oil quality fractions among a high-erucic Indian variety (Varuna), a low-erucic east-European variety (Heera) and a zero-erucic Indian variety (ZE-Varuna) developed by backcross breeding in this study indicated that lower levels of linoleic and linolenic acid in Varuna are due to substrate limitation caused by an active erucic acid pathway and not due to weaker alleles or enzyme limitation. To identify compensatory loci that could be used to increase oil content and maintain desirable levels of oil quality fractions under zero-erucic conditions, we performed Quantitative Trait Loci (QTL) mapping for the above traits on two independent F1 doubled haploid (F1DH) mapping populations developed from a cross between Varuna and Heera. One of the populations comprised plants segregating for erucic acid content (SE) and was used earlier for construction of a linkage map and QTL mapping of several yield-influencing traits in B. juncea. The second population consisted of zero-erucic acid individuals (ZE) for which, an Amplified Fragment Length Polymorphism (AFLP)-based framework linkage map was constructed in the present study. By QTL mapping for oil quality fractions and oil content in the ZE population, we detected novel loci contributing to the above traits. These loci did not co-localize with mapped locations of the fatty acid desaturase 2 (FAD2), fatty acid desaturase 3 (FAD3) or fatty acid elongase (FAE) genes unlike those of the SE population wherein major QTL were found to coincide with mapped locations of the FAE genes. Some of the new loci identified in the ZE population could be detected as 'weak' contributors (with LOD < 2.5) in the SE population in which their contribution to the traits was "masked" due to pleiotropic effects of erucic acid genes. The novel loci identified in this study could now be used to improve oil quality parameters and oil content in B. juncea under zero-erucic conditions.

Design of new genome- and gene-sourced primers and identification of QTL for seed oil content in a specially high-oil Brassica napus cultivar.

PubMed

Sun, Meiyu; Hua, Wei; Liu, Jing; Huang, Shunmou; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

2012-01-01

Rapeseed (Brassica napus L.) is one of most important oilseed crops in the world. There are now various rapeseed cultivars in nature that differ in their seed oil content because they vary in oil-content alleles and there are high-oil alleles among the high-oil rapeseed cultivars. For these experiments, we generated doubled haploid (DH) lines derived from the cross between the specially high-oil cultivar zy036 whose seed oil content is approximately 50% and the specially low-oil cultivar 51070 whose seed oil content is approximately 36%. First, to address the deficiency in polymorphic markers, we designed 5944 pairs of newly developed genome-sourced primers and 443 pairs of newly developed primers related to oil-content genes to complement the 2244 pairs of publicly available primers. Second, we constructed a new DH genetic linkage map using 527 molecular markers, consisting of 181 publicly available markers, 298 newly developed genome-sourced markers and 48 newly developed markers related to oil-content genes. The map contained 19 linkage groups, covering a total length of 2,265.54 cM with an average distance between markers of 4.30 cM. Third, we identified quantitative trait loci (QTL) for seed oil content using field data collected at three sites over 3 years, and found a total of 12 QTL. Of the 12 QTL associated with seed oil content identified, 9 were high-oil QTL which derived from the specially high-oil cultivar zy036. Two high-oil QTL on chromosomes A2 and C9 co-localized in two out of three trials. By QTL mapping for seed oil content, we found four candidate genes for seed oil content related to four gene markers: GSNP39, GSSR161, GIFLP106 and GIFLP046. This information will be useful for cloning functional genes correlated with seed oil content in the future.

Design of New Genome- and Gene-Sourced Primers and Identification of QTL for Seed Oil Content in a Specially High-Oil Brassica napus Cultivar

PubMed Central

Liu, Jing; Huang, Shunmou; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

2012-01-01

Rapeseed (Brassica napus L.) is one of most important oilseed crops in the world. There are now various rapeseed cultivars in nature that differ in their seed oil content because they vary in oil-content alleles and there are high-oil alleles among the high-oil rapeseed cultivars. For these experiments, we generated doubled haploid (DH) lines derived from the cross between the specially high-oil cultivar zy036 whose seed oil content is approximately 50% and the specially low-oil cultivar 51070 whose seed oil content is approximately 36%. First, to address the deficiency in polymorphic markers, we designed 5944 pairs of newly developed genome-sourced primers and 443 pairs of newly developed primers related to oil-content genes to complement the 2244 pairs of publicly available primers. Second, we constructed a new DH genetic linkage map using 527 molecular markers, consisting of 181 publicly available markers, 298 newly developed genome-sourced markers and 48 newly developed markers related to oil-content genes. The map contained 19 linkage groups, covering a total length of 2,265.54 cM with an average distance between markers of 4.30 cM. Third, we identified quantitative trait loci (QTL) for seed oil content using field data collected at three sites over 3 years, and found a total of 12 QTL. Of the 12 QTL associated with seed oil content identified, 9 were high-oil QTL which derived from the specially high-oil cultivar zy036. Two high-oil QTL on chromosomes A2 and C9 co-localized in two out of three trials. By QTL mapping for seed oil content, we found four candidate genes for seed oil content related to four gene markers: GSNP39, GSSR161, GIFLP106 and GIFLP046. This information will be useful for cloning functional genes correlated with seed oil content in the future. PMID:23077542

Verification and characterization of chromosome duplication in haploid maize.

PubMed

de Oliveira Couto, E G; Resende Von Pinho, E V; Von Pinho, R G; Veiga, A D; de Carvalho, M R; de Oliveira Bustamante, F; Nascimento, M S

2015-06-26

Doubled haploid technology has been used by various private companies. However, information regarding chromosome duplication methodologies, particularly those concerning techniques used to identify duplication in cells, is limited. Thus, we analyzed and characterized artificially doubled haploids using microsatellites molecular markers, pollen viability, and flow cytometry techniques. Evaluated material was obtained using two different chromosome duplication protocols in maize seeds considered haploids, resulting from the cross between the haploid inducer line KEMS and 4 hybrids (GNS 3225, GNS 3032, GNS 3264, and DKB 393). Fourteen days after duplication, plant samples were collected and assessed by flow cytometry. Further, the plants were transplanted to a field, and samples were collected for DNA analyses using microsatellite markers. The tassels were collected during anthesis for pollen viability analyses. Haploid, diploid, and mixoploid individuals were detected using flow cytometry, demonstrating that this technique was efficient for identifying doubled haploids. The microsatellites markers were also efficient for confirming the ploidies preselected by flow cytometry and for identifying homozygous individuals. Pollen viability showed a significant difference between the evaluated ploidies when the Alexander and propionic-carmin stains were used. The viability rates between the plodies analyzed show potential for fertilization.

Effective de novo assembly of fish genome using haploid larvae.

PubMed

Iwasaki, Yuki; Nishiki, Issei; Nakamura, Yoji; Yasuike, Motoshige; Kai, Wataru; Nomura, Kazuharu; Yoshida, Kazunori; Nomura, Yousuke; Fujiwara, Atushi; Kobayashi, Takanori; Ototake, Mitsuru

2016-02-01

Recent improvements in next-generation sequencing technology have made it possible to do whole genome sequencing, on even non-model eukaryote species with no available reference genomes. However, de novo assembly of diploid genomes is still a big challenge because of allelic variation. The aim of this study was to determine the feasibility of utilizing the genome of haploid fish larvae for de novo assembly of whole-genome sequences. We compared the efficiency of assembly using the haploid genome of yellowtail (Seriola quinqueradiata) with that using the diploid genome obtained from the dam. De novo assembly from the haploid and the diploid sequence reads (100 million reads per each datasets) generated by the Ion Proton sequencer (200 bp) was done under two different assembly algorithms, namely overlap-layout-consensus (OLC) and de Bruijn graph (DBG). This revealed that the assembly of the haploid genome significantly reduced (approximately 22% for OLC, 9% for DBG) the total number of contigs (with longer average and N50 contig lengths) when compared to the diploid genome assembly. The haploid assembly also improved the quality of the scaffolds by reducing the number of regions with unassigned nucleotides (Ns) (total length of Ns; 45,331,916 bp for haploids and 67,724,360 bp for diploids) in OLC-based assemblies. It appears clear that the haploid genome assembly is better because the allelic variation in the diploid genome disrupts the extension of contigs during the assembly process. Our results indicate that utilizing the genome of haploid larvae leads to a significant improvement in the de novo assembly process, thus providing a novel strategy for the construction of reference genomes from non-model diploid organisms such as fish. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Association of Dentine Hypersensitivity with Different Risk Factors – A Cross Sectional Study

PubMed Central

Vijaya, V; Sanjay, Venkataraam; Varghese, Rana K; Ravuri, Rajyalakshmi; Agarwal, Anil

2013-01-01

Background: This study was done to assess the prevalence of Dentine hypersensitivity (DH) and its associated risk factors. Materials & Methods: This epidemiological study was done among patients coming to dental college regarding prevalence of DH. A self structured questionnaire along with clinical examination was done for assessment. Descriptive statistics were obtained and frequency distribution was calculated using Chi square test at p value <0.05. Stepwise multiple linear regression was also done to access frequency of DH with different factors. Results: The study population was comprised of 655 participants with different age groups. Our study showed prevalence as 55% and it was more common among males. Similarly smokers and those who use hard tooth brush had more cases of DH. Step wise multiple linear regression showed that best predictor for DH was age followed by habit of smoking and type of tooth brush. Most aggravating factors were cold water (15.4%) and sweet foods (14.7%), whereas only 5% of the patients had it while brushing. Conclusion: A high level of dental hypersensitivity has been in this study and more common among males. A linear finding was shown with age, smoking and type of tooth brush. How to cite this article: Vijaya V, Sanjay V, Varghese RK, Ravuri R, Agarwal A. Association of Dentine Hypersensitivity with Different Risk Factors – A Cross Sectional Study. J Int Oral Health 2013;5(6):88-92 . PMID:24453451

Induced parthenogenesis by gamma-irradiated pollen in loquat for haploid production.

PubMed

Blasco, Manuel; Badenes, María Luisa; Del Mar Naval, María

2016-09-01

Successful haploid induction in loquat ( Eriobotrya japonica (Thunb.) Lindl.) through in situ-induced parthenogenesis with gamma-ray irradiated pollen has been achieved. Female flowers of cultivar 'Algerie' were pollinated using pollen of cultivars 'Changhong-3', 'Cox' and 'Saval Brasil' irradiated with two doses of gamma rays, 150 and 300 Gy. The fruits were harvested 90, 105 and 120 days after pollination (dap). Four haploid plants were obtained from 'Algerie' pollinated with 300-Gy-treated pollen of 'Saval Brasil' from fruits harvested 105 dap. Haploidy was confirmed by flow cytometry and chromosome count. The haploids showed a very weak development compared to the diploid plants. This result suggests that irradiated pollen can be used to obtain parthenogenetic haploids.

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2010-09-23

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Molecular evolution and transcriptional regulation of the oilseed rape proline dehydrogenase genes suggest distinct roles of proline catabolism during development.

PubMed

Faës, Pascal; Deleu, Carole; Aïnouche, Abdelkader; Le Cahérec, Françoise; Montes, Emilie; Clouet, Vanessa; Gouraud, Anne-Marie; Albert, Benjamin; Orsel, Mathilde; Lassalle, Gilles; Leport, Laurent; Bouchereau, Alain; Niogret, Marie-Françoise

2015-02-01

Six BnaProDH1 and two BnaProDH2 genes were identified in Brassica napus genome. The BnaProDH1 genes are mainly expressed in pollen and roots' organs while BnaProDH2 gene expression is associated with leaf vascular tissues at senescence. Proline dehydrogenase (ProDH) catalyzes the first step in the catabolism of proline. The ProDH gene family in oilseed rape (Brassica napus) was characterized and compared to other Brassicaceae ProDH sequences to establish the phylogenetic relationships between genes. Six BnaProDH1 genes and two BnaProDH2 genes were identified in the B. napus genome. Expression of the three paralogous pairs of BnaProDH1 genes and the two homoeologous BnaProDH2 genes was measured by real-time quantitative RT-PCR in plants at vegetative and reproductive stages. The BnaProDH2 genes are specifically expressed in vasculature in an age-dependent manner, while BnaProDH1 genes are strongly expressed in pollen grains and roots. Compared to the abundant expression of BnaProDH1, the overall expression of BnaProDH2 is low except in roots and senescent leaves. The BnaProDH1 paralogs showed different levels of expression with BnaA&C.ProDH1.a the most strongly expressed and BnaA&C.ProDH1.c the least. The promoters of two BnaProDH1 and two BnaProDH2 genes were fused with uidA reporter gene (GUS) to characterize organ and tissue expression profiles in transformed B. napus plants. The transformants with promoters from different genes showed contrasting patterns of GUS activity, which corresponded to the spatial expression of their respective transcripts. ProDHs probably have non-redundant functions in different organs and at different phenological stages. In terms of molecular evolution, all BnaProDH sequences appear to have undergone strong purifying selection and some copies are becoming subfunctionalized. This detailed description of oilseed rape ProDH genes provides new elements to investigate the function of proline metabolism in plant development.

Validation of Fusarium head blight resistance QTL using the NC-Neuse / Bess doubled haploid population

USDA-ARS?s Scientific Manuscript database

Fusarium Head Blight (FHB) is one of the most damaging diseases of wheat. It lowers the grain yield and quality, and contaminates grain with the mycotoxin deoxynivalenol (DON). Genetic resistance is a critical control measure and breeding objective. Many studies have focused on the genetic basis of ...

Chemical reproductive traits of diploid Bombus terrestris males: Consequences on bumblebee conservation.

PubMed

Lecocq, Thomas; Gérard, Maxence; Maebe, Kevin; Brasero, Nicolas; Dehon, Lauren; Smagghe, Guy; Valterová, Irena; De Meulemeester, Thibaut; Rasmont, Pierre; Michez, Denis

2017-08-01

The current bumblebee decline leads to inbreeding in populations that fosters a loss of allelic diversity and diploid male production. As diploid males are viable and their offspring are sterile, bumblebee populations can quickly fall in a vortex of extinction. In this article, we investigate for the first time a potential premating mechanism through a major chemical reproductive trait (male cephalic labial gland secretions) that could prevent monandrous virgin queens from mating with diploid males. We focus our study on the cephalic labial gland secretions of diploid and haploid males of Bombus terrestris (L.). Contrary to initial expectations, our results do not show any significant differentiation of cephalic labial gland secretions between diploid and haploid specimens. Queens seem therefore to be unable to avoid mating with diploid males based on their compositions of cephalic labial gland secretions. This suggests that the vortex of extinction of diploid males could not be stopped through premating avoidance based on the cephalic labial gland secretions but other mechanisms could avoid mating between diploid males and queens. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Modeling evolution of spatially distributed bacterial communities: a simulation with the haploid evolutionary constructor

PubMed Central

2015-01-01

Background Multiscale approaches for integrating submodels of various levels of biological organization into a single model became the major tool of systems biology. In this paper, we have constructed and simulated a set of multiscale models of spatially distributed microbial communities and study an influence of unevenly distributed environmental factors on the genetic diversity and evolution of the community members. Results Haploid Evolutionary Constructor software http://evol-constructor.bionet.nsc.ru/ was expanded by adding the tool for the spatial modeling of a microbial community (1D, 2D and 3D versions). A set of the models of spatially distributed communities was built to demonstrate that the spatial distribution of cells affects both intensity of selection and evolution rate. Conclusion In spatially heterogeneous communities, the change in the direction of the environmental flow might be reflected in local irregular population dynamics, while the genetic structure of populations (frequencies of the alleles) remains stable. Furthermore, in spatially heterogeneous communities, the chemotaxis might dramatically affect the evolution of community members. PMID:25708911

Identification of Dh/+ and Dh/Dh embryos through close linkage of Dh and peptidase-3.

PubMed

Holmes, L B

1986-12-01

The close linkage between the genes Dominant hemimelia (Dh) and peptidase-3 (Pep-3) has been determined in 65 informative matings with the recombination frequency of 3.8%. Progeny testing showed that nonpenetrance does occur in Dh/+ adults. The presence of the "slow" and "fast" variants of Pep-3 can be determined in homogenates of kidney tissue as well as in a portion of the day 10 and 11 embryos. In a litter of embryos born to an informative mating, those which are Dh/Dh, Dh/+, and +/+ can be distinguished by the presence of the Pep-3 allele known to be in coupling with the Dh gene. This technique makes it possible to identify and to study the limb malformations and other phenotypic effects of Dh during their development and before the limb deformity is visible.

A New Single Nucleotide Polymorphism Database for Rainbow Trout Generated Through Whole Genome Resequencing.

PubMed

Gao, Guangtu; Nome, Torfinn; Pearse, Devon E; Moen, Thomas; Naish, Kerry A; Thorgaard, Gary H; Lien, Sigbjørn; Palti, Yniv

2018-01-01

Single-nucleotide polymorphisms (SNPs) are highly abundant markers, which are broadly distributed in animal genomes. For rainbow trout ( Oncorhynchus mykiss ), SNP discovery has been previously done through sequencing of restriction-site associated DNA (RAD) libraries, reduced representation libraries (RRL) and RNA sequencing. Recently we have performed high coverage whole genome resequencing with 61 unrelated samples, representing a wide range of rainbow trout and steelhead populations, with 49 new samples added to 12 aquaculture samples from AquaGen (Norway) that we previously used for SNP discovery. Of the 49 new samples, 11 were double-haploid lines from Washington State University (WSU) and 38 represented wild and hatchery populations from a wide range of geographic distribution and with divergent migratory phenotypes. We then mapped the sequences to the new rainbow trout reference genome assembly (GCA_002163495.1) which is based on the Swanson YY doubled haploid line. Variant calling was conducted with FreeBayes and SAMtools mpileup , followed by filtering of SNPs based on quality score, sequence complexity, read depth on the locus, and number of genotyped samples. Results from the two variant calling programs were compared and genotypes of the double haploid samples were used for detecting and filtering putative paralogous sequence variants (PSVs) and multi-sequence variants (MSVs). Overall, 30,302,087 SNPs were identified on the rainbow trout genome 29 chromosomes and 1,139,018 on unplaced scaffolds, with 4,042,723 SNPs having high minor allele frequency (MAF > 0.25). The average SNP density on the chromosomes was one SNP per 64 bp, or 15.6 SNPs per 1 kb. Results from the phylogenetic analysis that we conducted indicate that the SNP markers contain enough population-specific polymorphisms for recovering population relationships despite the small sample size used. Intra-Population polymorphism assessment revealed high level of polymorphism and heterozygosity within each population. We also provide functional annotation based on the genome position of each SNP and evaluate the use of clonal lines for filtering of PSVs and MSVs. These SNPs form a new database, which provides an important resource for a new high density SNP array design and for other SNP genotyping platforms used for genetic and genomics studies of this iconic salmonid fish species.

Production of viable homozygous, doubled haploid channel catfish (Ictalurus punctatus)

USDA-ARS?s Scientific Manuscript database

Production of doubled haploids via mitotic gynogenesis is a useful tool for the creation of completely inbred fish. In order to produce viable doubled haploid channel catfish, we utilized hydrostatic pressure or thermal treatments on eggs fertilized with sperm that had been exposed to ultraviolet l...

Induced parthenogenesis by gamma-irradiated pollen in loquat for haploid production

PubMed Central

Blasco, Manuel; Badenes, María Luisa; del Mar Naval, María

2016-01-01

Successful haploid induction in loquat (Eriobotrya japonica (Thunb.) Lindl.) through in situ-induced parthenogenesis with gamma-ray irradiated pollen has been achieved. Female flowers of cultivar ‘Algerie’ were pollinated using pollen of cultivars ‘Changhong-3’, ‘Cox’ and ‘Saval Brasil’ irradiated with two doses of gamma rays, 150 and 300 Gy. The fruits were harvested 90, 105 and 120 days after pollination (dap). Four haploid plants were obtained from ‘Algerie’ pollinated with 300-Gy-treated pollen of ‘Saval Brasil’ from fruits harvested 105 dap. Haploidy was confirmed by flow cytometry and chromosome count. The haploids showed a very weak development compared to the diploid plants. This result suggests that irradiated pollen can be used to obtain parthenogenetic haploids. PMID:27795686

Use of doubled haploid technology for development of stable drought tolerant bread wheat (Triticum aestivum L.) transgenics.

PubMed

Chauhan, Harsh; Khurana, Paramjit

2011-04-01

Anther culture-derived haploid embryos were used as explants for Agrobacterium-mediated genetic transformation of bread wheat (Triticum aestivum L. cv CPAN1676) using barley HVA1 gene for drought tolerance. Regenerated plantlets were checked for transgene integration in T₀ generation, and positive transgenic haploid plants were doubled by colchicine treatment. Stable transgenic doubled haploid plants were obtained, and transgene expression was monitored till T₄ generation, and no transgene silencing was observed over the generations. Doubled haploid transgenic plants have faster seed germination and seedling establishment and show better drought tolerance in comparison with nontransgenic, doubled haploid plants, as measured by per cent germination, seedling growth and biomass accumulation. Physiological evaluation for abiotic stress by assessing nitrate reductase enzyme activity and plant yield under post-anthesis water limitation revealed a better tolerance of the transgenics over the wild type. This is the first report on the production of double haploid transgenic wheat through anther culture technique in a commercial cultivar for a desirable trait. This method would also be useful in functional genomics of wheat and other allopolyploids of agronomic importance. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

The role of epistatic interactions underpinning resistance to parasitic Varroa mites in haploid honey bee (Apis mellifera) drones.

PubMed

Conlon, Benjamin H; Frey, Eva; Rosenkranz, Peter; Locke, Barbara; Moritz, Robin F A; Routtu, Jarkko

2018-06-01

The Red Queen hypothesis predicts that host-parasite coevolutionary dynamics can select for host resistance through increased genetic diversity, recombination and evolutionary rates. However, in haplodiploid organisms such as the honeybee (Apis mellifera), models suggest the selective pressure is weaker than in diploids. Haplodiploid sex determination, found in A. mellifera, can allow deleterious recessive alleles to persist in the population through the diploid sex with negative effects predominantly expressed in the haploid sex. To overcome these negative effects in haploid genomes, epistatic interactions have been hypothesized to play an important role. Here, we use the interaction between A. mellifera and the parasitic mite Varroa destructor to test epistasis in the expression of resistance, through the inhibition of parasite reproduction, in haploid drones. We find novel loci on three chromosomes which explain over 45% of the resistance phenotype. Two of these loci interact only additively, suggesting their expression is independent of each other, but both loci interact epistatically with the third locus. With drone offspring inheriting only one copy of the queen's chromosomes, the drones will only possess one of two queen alleles throughout the years-long lifetime of the honeybee colony. Varroa, in comparison, completes its highly inbred reproductive cycle in a matter of weeks, allowing it to rapidly evolve resistance. Faced with the rapidly evolving Varroa, a diversity of pathways and epistatic interactions for the inhibition of Varroa reproduction could therefore provide a selective advantage to the high levels of recombination seen in A. mellifera. This allows for the remixing of phenotypes despite a fixed queen genotype. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Spatial Genetic Structure of the Abundant and Widespread Peatmoss Sphagnum magellanicum Brid.

PubMed Central

Kyrkjeeide, Magni Olsen; Hassel, Kristian; Flatberg, Kjell Ivar; Shaw, A. Jonathan; Yousefi, Narjes; Stenøien, Hans K.

2016-01-01

Spore-producing organisms have small dispersal units enabling them to become widespread across continents. However, barriers to gene flow and cryptic speciation may exist. The common, haploid peatmoss Sphagnum magellanicum occurs in both the Northern and Southern hemisphere, and is commonly used as a model in studies of peatland ecology and peatmoss physiology. Even though it will likely act as a rich source in functional genomics studies in years to come, surprisingly little is known about levels of genetic variability and structuring in this species. Here, we assess for the first time how genetic variation in S. magellanicum is spatially structured across its full distribution range (Northern Hemisphere and South America). The morphologically similar species S. alaskense was included for comparison. In total, 195 plants were genotyped at 15 microsatellite loci. Sequences from two plastid loci (trnG and trnL) were obtained from 30 samples. Our results show that S. alaskense and almost all plants of S. magellanicum in the northern Pacific area are diploids and share the same gene pool. Haploid plants occur in South America, Europe, eastern North America, western North America, and southern Asia, and five genetically differentiated groups with different distribution ranges were found. Our results indicate that S. magellanicum consists of several distinct genetic groups, seemingly with little or no gene flow among them. Noteworthy, the geographical separation of diploids and haploids is strikingly similar to patterns found within other haploid Sphagnum species spanning the Northern Hemisphere. Our results confirm a genetic division between the Beringian and the Atlantic that seems to be a general pattern in Sphagnum taxa. The pattern of strong genetic population structuring throughout the distribution range of morphologically similar plants need to be considered in future functional genomic studies of S. magellanicum. PMID:26859563

Spatial Genetic Structure of the Abundant and Widespread Peatmoss Sphagnum magellanicum Brid.

PubMed

Kyrkjeeide, Magni Olsen; Hassel, Kristian; Flatberg, Kjell Ivar; Shaw, A Jonathan; Yousefi, Narjes; Stenøien, Hans K

2016-01-01

Spore-producing organisms have small dispersal units enabling them to become widespread across continents. However, barriers to gene flow and cryptic speciation may exist. The common, haploid peatmoss Sphagnum magellanicum occurs in both the Northern and Southern hemisphere, and is commonly used as a model in studies of peatland ecology and peatmoss physiology. Even though it will likely act as a rich source in functional genomics studies in years to come, surprisingly little is known about levels of genetic variability and structuring in this species. Here, we assess for the first time how genetic variation in S. magellanicum is spatially structured across its full distribution range (Northern Hemisphere and South America). The morphologically similar species S. alaskense was included for comparison. In total, 195 plants were genotyped at 15 microsatellite loci. Sequences from two plastid loci (trnG and trnL) were obtained from 30 samples. Our results show that S. alaskense and almost all plants of S. magellanicum in the northern Pacific area are diploids and share the same gene pool. Haploid plants occur in South America, Europe, eastern North America, western North America, and southern Asia, and five genetically differentiated groups with different distribution ranges were found. Our results indicate that S. magellanicum consists of several distinct genetic groups, seemingly with little or no gene flow among them. Noteworthy, the geographical separation of diploids and haploids is strikingly similar to patterns found within other haploid Sphagnum species spanning the Northern Hemisphere. Our results confirm a genetic division between the Beringian and the Atlantic that seems to be a general pattern in Sphagnum taxa. The pattern of strong genetic population structuring throughout the distribution range of morphologically similar plants need to be considered in future functional genomic studies of S. magellanicum.

Invasion of novel habitats uncouples haplo-diplontic life cycles.

PubMed

Krueger-Hadfield, Stacy A; Kollars, Nicole M; Byers, James E; Greig, Thomas W; Hammann, Mareike; Murray, David C; Murren, Courtney J; Strand, Allan E; Terada, Ryuta; Weinberger, Florian; Sotka, Erik E

2016-08-01

Baker's Law predicts uniparental reproduction will facilitate colonization success in novel habitats. While evidence supports this prediction among colonizing plants and animals, few studies have investigated shifts in reproductive mode in haplo-diplontic species in which both prolonged haploid and diploid stages separate meiosis and fertilization in time and space. Due to this separation, asexual reproduction can yield the dominance of one of the ploidy stages in colonizing populations. We tested for shifts in ploidy and reproductive mode across native and introduced populations of the red seaweed Gracilaria vermiculophylla. Native populations in the northwest Pacific Ocean were nearly always attached by holdfasts to hard substrata and, as is characteristic of the genus, haploid-diploid ratios were slightly diploid-biased. In contrast, along North American and European coastlines, introduced populations nearly always floated atop soft-sediment mudflats and were overwhelmingly dominated by diploid thalli without holdfasts. Introduced populations exhibited population genetic signals consistent with extensive vegetative fragmentation, while native populations did not. Thus, the ecological shift from attached to unattached thalli, ostensibly necessitated by the invasion of soft-sediment habitats, correlated with shifts from sexual to asexual reproduction and slight to strong diploid bias. We extend Baker's Law by predicting other colonizing haplo-diplontic species will show similar increases in asexuality that correlate with the dominance of one ploidy stage. Labile mating systems likely facilitate colonization success and subsequent range expansion, but for haplo-diplontic species, the long-term eco-evolutionary impacts will depend on which ploidy stage is lost and the degree to which asexual reproduction is canalized. © 2016 John Wiley & Sons Ltd.

Isolation of UmRrm75, a gene involved in dimorphism and virulence of Ustilago maydis

USDA-ARS?s Scientific Manuscript database

Ustilago maydis displays dimorphic growth, alternating between a saprophytic haploid yeast form and a filamentous dikaryon, generated by mating of haploid cells and which is an obligate parasite. Induction of the dimorphic transition of haploid strains in vitro by change in ambient pH has been used...

Unravelling the distinct strains of Tharu ancestry.

PubMed

Chaubey, Gyaneshwer; Singh, Manvendra; Crivellaro, Federica; Tamang, Rakesh; Nandan, Amrita; Singh, Kamayani; Sharma, Varun Kumar; Pathak, Ajai Kumar; Shah, Anish M; Sharma, Vishwas; Singh, Vipin Kumar; Selvi Rani, Deepa; Rai, Niraj; Kushniarevich, Alena; Ilumäe, Anne-Mai; Karmin, Monika; Phillip, Anand; Verma, Abhilasha; Prank, Erik; Singh, Vijay Kumar; Li, Blaise; Govindaraj, Periyasamy; Chaubey, Akhilesh Kumar; Dubey, Pavan Kumar; Reddy, Alla G; Premkumar, Kumpati; Vishnupriya, Satti; Pande, Veena; Parik, Jüri; Rootsi, Siiri; Endicott, Phillip; Metspalu, Mait; Lahr, Marta Mirazon; van Driem, George; Villems, Richard; Kivisild, Toomas; Singh, Lalji; Thangaraj, Kumarasamy

2014-12-01

The northern region of the Indian subcontinent is a vast landscape interlaced by diverse ecologies, for example, the Gangetic Plain and the Himalayas. A great number of ethnic groups are found there, displaying a multitude of languages and cultures. The Tharu is one of the largest and most linguistically diverse of such groups, scattered across the Tarai region of Nepal and bordering Indian states. Their origins are uncertain. Hypotheses have been advanced postulating shared ancestry with Austroasiatic, or Tibeto-Burman-speaking populations as well as aboriginal roots in the Tarai. Several Tharu groups speak a variety of Indo-Aryan languages, but have traditionally been described by ethnographers as representing East Asian phenotype. Their ancestry and intra-population diversity has previously been tested only for haploid (mitochondrial DNA and Y-chromosome) markers in a small portion of the population. This study presents the first systematic genetic survey of the Tharu from both Nepal and two Indian states of Uttarakhand and Uttar Pradesh, using genome-wide SNPs and haploid markers. We show that the Tharu have dual genetic ancestry as up to one-half of their gene pool is of East Asian origin. Within the South Asian proportion of the Tharu genetic ancestry, we see vestiges of their common origin in the north of the South Asian Subcontinent manifested by mitochondrial DNA haplogroup M43.

The mixed mating system of the sea palm kelp Postelsia palmaeformis: few costs to selfing

PubMed Central

Barner, Allison K.; Pfister, Catherine A.; Wootton, J. Timothy

2011-01-01

Naturally isolated populations have conflicting selection pressures for successful reproduction and inbreeding avoidance. These species with limited seasonal reproductive opportunities may use selfing as a means of reproductive assurance. We quantified the frequency of selfing and the fitness consequences for inbred versus outcrossed progeny of an annual kelp, the sea palm (Postelsia palmaeformis). Using experimentally established populations and microsatellite markers to assess the extent of selfing in progeny from six founding parents, we found the frequency of selfing was higher than expected in every population, and few fitness costs were detected in selfed offspring. Despite a decline in heterozygosity of 30 per cent in the first generation of selfing, self-fertilization did not affect individual size or reproduction, and correlated only with a marginally significant decline in survival. Our results suggest both that purging of deleterious recessive alleles may have already occurred and that selfing may be key to reproductive assurance in this species with limited dispersal. Postelsia has an alteration of a free-living diploid and haploid stage, where the haploid stage may provide increased efficiency for purging the genetic load. This life history is shared by many seaweeds and may thus be an important component of mating system evolution in the sea. PMID:20961896

Genome-Wide Mutation Avalanches Induced in Diploid Yeast Cells by a Base Analog or an APOBEC Deaminase

PubMed Central

Lada, Artem G.; Stepchenkova, Elena I.; Waisertreiger, Irina S. R.; Noskov, Vladimir N.; Dhar, Alok; Eudy, James D.; Boissy, Robert J.; Hirano, Masayuki; Rogozin, Igor B.; Pavlov, Youri I.

2013-01-01

Genetic information should be accurately transmitted from cell to cell; conversely, the adaptation in evolution and disease is fueled by mutations. In the case of cancer development, multiple genetic changes happen in somatic diploid cells. Most classic studies of the molecular mechanisms of mutagenesis have been performed in haploids. We demonstrate that the parameters of the mutation process are different in diploid cell populations. The genomes of drug-resistant mutants induced in yeast diploids by base analog 6-hydroxylaminopurine (HAP) or AID/APOBEC cytosine deaminase PmCDA1 from lamprey carried a stunning load of thousands of unselected mutations. Haploid mutants contained almost an order of magnitude fewer mutations. To explain this, we propose that the distribution of induced mutation rates in the cell population is uneven. The mutants in diploids with coincidental mutations in the two copies of the reporter gene arise from a fraction of cells that are transiently hypersensitive to the mutagenic action of a given mutagen. The progeny of such cells were never recovered in haploids due to the lethality caused by the inactivation of single-copy essential genes in cells with too many induced mutations. In diploid cells, the progeny of hypersensitive cells survived, but their genomes were saturated by heterozygous mutations. The reason for the hypermutability of cells could be transient faults of the mutation prevention pathways, like sanitization of nucleotide pools for HAP or an elevated expression of the PmCDA1 gene or the temporary inability of the destruction of the deaminase. The hypothesis on spikes of mutability may explain the sudden acquisition of multiple mutational changes during evolution and carcinogenesis. PMID:24039593

Dissecting BMP signaling input into the gene regulatory networks driving specification of the blood stem cell lineage

PubMed Central

Kirmizitas, Arif; Meiklejohn, Stuart; Ciau-Uitz, Aldo; Stephenson, Rachel; Patient, Roger

2017-01-01

Hematopoietic stem cells (HSCs) that sustain lifelong blood production are created during embryogenesis. They emerge from a specialized endothelial population, termed hemogenic endothelium (HE), located in the ventral wall of the dorsal aorta (DA). In Xenopus, we have been studying the gene regulatory networks (GRNs) required for the formation of HSCs, and critically found that the hemogenic potential is defined at an earlier time point when precursors to the DA express hematopoietic as well as endothelial genes, in the definitive hemangioblasts (DHs). The GRN for DH programming has been constructed and, here, we show that bone morphogenetic protein (BMP) signaling is essential for the initiation of this GRN. BMP2, -4, and -7 are the principal ligands expressed in the lineage forming the HE. To investigate the requirement and timing of all BMP signaling in HSC ontogeny, we have used a transgenic line, which inducibly expresses an inhibitor of BMP signaling, Noggin, as well as a chemical inhibitor of BMP receptors, DMH1, and described the inputs from BMP signaling into the DH GRN and the HE, as well as into primitive hematopoiesis. BMP signaling is required in at least three points in DH programming: first to initiate the DH GRN through gata2 expression, then for kdr expression to enable the DH to respond to vascular endothelial growth factor A (VEGFA) ligand from the somites, and finally for gata2 expression in the DA, but is dispensable for HE specification after hemangioblasts have been formed. PMID:28584091

Bacterial Metabolism of Chlorinated Dehydroabietic Acids Occurring in Pulp and Paper Mill Effluents

PubMed Central

Mohn, W. W.; Stewart, G. R.

1997-01-01

Chlorinated dehydroabietic acids are formed during the chlorine bleaching of wood pulp and are very toxic to fish. Thus, destruction of these compounds is an important function of biological treatment systems for pulp and paper mill effluents. In this study, 12 strains of diverse, aerobic resin acid-degrading bacteria were screened for the ability to grow on chlorinated dehydroabietic acids as sole organic substrates. All seven strains of the class Proteobacteria able to use dehydroabietic acid were also able to use a mixture of 12- and 14-chlorodehydroabietic acid (Cl-DhA). None of the strains used 12,14-dichlorodehydroabietic acid. Sphingomonas sp. strain DhA-33 grew best on Cl-DhA and simultaneously removed both Cl-DhA isomers. Ralstonia sp. strain BKME-6 was typical of most of the strains tested, growing more slowly on Cl-DhA and leaving higher residual concentrations of Cl-DhA than DhA-33 did. Strains DhA-33 and BKME-6 mineralized (converted to CO(inf2) plus biomass) 32 and 43%, respectively, of carbon in Cl-DhA consumed. Strain DhA-33 produced a metabolite from Cl-DhA, tentatively identified as 3-oxo-14-chlorodehydroabietin, and both strains produced dissolved organic carbon which may include unidentified metabolites. Cl-DhA removal was inducible in both DhA-33 and BKME-6, and induced DhA-33 cells also removed 12,14-dichlorodehydroabietic acid. Based on activities of strains DhA-33 and BKME-6, chlorinated DhAs, and potentially toxic metabolite(s) of these compounds, are relatively persistent in biological treatment systems and in the environment. PMID:16535663

Schrödinger’s Cheshire Cat: Are Haploid Emiliania huxleyi Cells Resistant to Viral Infection or Not?

PubMed Central

Mordecai, Gideon J.; Verret, Frederic; Highfield, Andrea; Schroeder, Declan C.

2017-01-01

Emiliania huxleyi is the main calcite producer on Earth and is routinely infected by a virus (EhV); a double stranded DNA (dsDNA) virus belonging to the family Phycodnaviridae. E. huxleyi exhibits a haplodiploid life cycle; the calcified diploid stage is non-motile and forms extensive blooms. The haploid phase is a non-calcified biflagellated cell bearing organic scales. Haploid cells are thought to resist infection, through a process deemed the “Cheshire Cat” escape strategy; however, a recent study detected the presence of viral lipids in the same haploid strain. Here we report on the application of an E. huxleyi CCMP1516 EhV-86 combined tiling array (TA) that further confirms an EhV infection in the RCC1217 haploid strain, which grew without any signs of cell lysis. Reverse transcription polymerase chain reaction (RT-PCR) and PCR verified the presence of viral RNA in the haploid cells, yet indicated an absence of viral DNA, respectively. These infected cells are an alternative stage of the virus life cycle deemed the haplococcolithovirocell. In this instance, the host is both resistant to and infected by EhV, i.e., the viral transcriptome is present in haploid cells whilst there is no evidence of viral lysis. This superimposed state is reminiscent of Schrödinger’s cat; of being simultaneously both dead and alive. PMID:28335465

Schrödinger's Cheshire Cat: Are Haploid Emiliania huxleyi Cells Resistant to Viral Infection or Not?

PubMed

Mordecai, Gideon J; Verret, Frederic; Highfield, Andrea; Schroeder, Declan C

2017-03-18

Emiliania huxleyi is the main calcite producer on Earth and is routinely infected by a virus (EhV); a double stranded DNA (dsDNA) virus belonging to the family Phycodnaviridae . E. huxleyi exhibits a haplodiploid life cycle; the calcified diploid stage is non-motile and forms extensive blooms. The haploid phase is a non-calcified biflagellated cell bearing organic scales. Haploid cells are thought to resist infection, through a process deemed the "Cheshire Cat" escape strategy; however, a recent study detected the presence of viral lipids in the same haploid strain. Here we report on the application of an E. huxleyi CCMP1516 EhV-86 combined tiling array (TA) that further confirms an EhV infection in the RCC1217 haploid strain, which grew without any signs of cell lysis. Reverse transcription polymerase chain reaction (RT-PCR) and PCR verified the presence of viral RNA in the haploid cells, yet indicated an absence of viral DNA, respectively. These infected cells are an alternative stage of the virus life cycle deemed the haplococcolithovirocell. In this instance, the host is both resistant to and infected by EhV, i.e., the viral transcriptome is present in haploid cells whilst there is no evidence of viral lysis. This superimposed state is reminiscent of Schrödinger's cat; of being simultaneously both dead and alive.

Catalyzing healthcare transformation with digital health: Performance indicators and lessons learned from a Digital Health Innovation Group.

PubMed

Tseng, Jocelyn; Samagh, Sonia; Fraser, Donna; Landman, Adam B

2018-06-01

Despite considerable investment in digital health (DH) companies and a growing DH ecosystem, there are multiple challenges to testing and implementing innovative solutions. Health systems have recognized the potential of DH and have formed DH innovation centers. However, limited information is available on DH innovation center processes, best practices, or outcomes. This case report describes a DH innovation center process that can be replicated across health systems and defines and benchmarks process indicators to assess DH innovation center performance. The Brigham and Women's Hospital's Digital Health Innovation Group (DHIG) accelerates DH innovations from idea to pilot safely and efficiently using a structured process. Fifty-four DH innovations were accelerated by the DHIG process between July 2014 and December 2016. In order to measure effectiveness of the DHIG process, key process indicators were defined as 1) number of solutions that completed each DHIG phase and 2) length of time to complete each phase. Twenty-three DH innovations progressed to pilot stage and 13 innovations were terminated after barriers to pilot implementation were identified by the DHIG process. For 4 DH solutions that executed a pilot, the average time for innovations to proceed from DHIG intake to pilot initiation was 9 months. Overall, the DHIG is a reproducible process that addresses key roadblocks in DH innovation within health systems. To our knowledge, this is the first report to describe DH innovation process indicators and results within an academic health system. Therefore, there is no published data to compare our results with the results of other DH innovation centers. Standardized data collection and indicator reporting could allow benchmark comparisons across institutions. Additional opportunities exist for the validation of DH solution effectiveness and for translational support from pilot to implementation. These are critical steps to advance DH technologies and effectively leverage the DH ecosystem to transform healthcare. Copyright © 2017 Elsevier Inc. All rights reserved.

Induction of gynogenetic and androgenetic haploid and doubled haploid development in the brown trout (Salmo trutta Linnaeus 1758).

PubMed

Michalik, O; Dobosz, S; Zalewski, T; Sapota, M; Ocalewicz, K

2015-04-01

Gynogenetic and androgenetic brown trout (Salmo trutta Linnaeus 1758) haploids (Hs) and doubled haploids (DHs) were produced in the present research. Haploid development was induced by radiation-induced genetic inactivation of spermatozoa (gynogenesis) or eggs (androgenesis) before insemination. To provide DHs, gynogenetic and androgenetic haploid zygotes were subjected to the high pressure shock to suppress the first mitotic cleavage. Among haploids, gynogenetic embryos were showing lower mortality when compared to the androgenetic embryos; however, most of them die before the first feeding stage. Gynogenetic doubled haploids provided in the course of the brown trout eggs activation performed by homologous and heterologous sperm (rainbow trout) were developing equally showing hatching rates of 14.76 ± 2.4% and 16.14 ± 2.90% and the survival rates at the first feeding stage of 10.48 ± 3.48% and 12.78 ± 2.18%, respectively. Significantly, lower survival rate was observed among androgenetic progenies from the diploid groups with only few specimens that survived to the first feeding stage. Cytogenetic survey showed that among embryos from the diploid variants of the research, only gynogenetic individuals possessed doubled sets of chromosomes. Thus, it is reasonable to assume that radiation employed for the genetic inactivation of the brown trout eggs misaligned mechanism responsible for the cell divisions and might have delayed or even arrested the first mitotic cleavage in the androgenetic brown trout zygotes. Moreover, protocol for the radiation-induced inactivation of the paternal and maternal genome should be adjusted as some of the cytogenetically surveyed gynogenetic and androgenetic embryos exhibited fragments of the irradiated chromosomes. © 2015 Blackwell Verlag GmbH.

Comparative modeling of coevolution in communities of unicellular organisms: adaptability and biodiversity.

PubMed

Lashin, Sergey A; Suslov, Valentin V; Matushkin, Yuri G

2010-06-01

We propose an original program "Evolutionary constructor" that is capable of computationally efficient modeling of both population-genetic and ecological problems, combining these directions in one model of required detail level. We also present results of comparative modeling of stability, adaptability and biodiversity dynamics in populations of unicellular haploid organisms which form symbiotic ecosystems. The advantages and disadvantages of two evolutionary strategies of biota formation--a few generalists' taxa-based biota formation and biodiversity-based biota formation--are discussed.

Annotation of Different Dehydrocatechin Oligomers by MS/MS and Their Occurrence in Black Tea.

PubMed

Verloop, Annewieke J W; Gruppen, Harry; Vincken, Jean-Paul

2016-08-03

Dehydrocatechins (DhC's), oligomeric oxidation products of (epi)catechins, were formed in model incubations of epicatechin with mushroom tyrosinase. DhC oligomers up to tetramers were detected by reversed-phase ultrahigh-performance liquid chromatography mass spectrometry (RP-UHPLC-MS) analysis. Measurements with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) showed formation of oligomers up to at least 15 catechin subunits. Isomeric DhC's were obtained, and a method based on MS(2) fragment ratios was set up to distinguish between the different interflavanic configurations of the isomers. In the model incubation, 8 dehydrodicatechins (DhC2's) and 22 dehydrotricatechins (DhC3's) were tentatively annotated by their MS(2) signature fragments. Three different interflavanic configuration types were determined for the DhC2's. DhC2's and DhC3's were shown to occur in a black tea extract for the first time. For the DhC2's, at least two isomeric types, i.e., DhC β and DhC ε, could be annotated in black tea.

Critical Mutation Rate Has an Exponential Dependence on Population Size in Haploid and Diploid Populations

PubMed Central

Aston, Elizabeth; Channon, Alastair; Day, Charles; Knight, Christopher G.

2013-01-01

Understanding the effect of population size on the key parameters of evolution is particularly important for populations nearing extinction. There are evolutionary pressures to evolve sequences that are both fit and robust. At high mutation rates, individuals with greater mutational robustness can outcompete those with higher fitness. This is survival-of-the-flattest, and has been observed in digital organisms, theoretically, in simulated RNA evolution, and in RNA viruses. We introduce an algorithmic method capable of determining the relationship between population size, the critical mutation rate at which individuals with greater robustness to mutation are favoured over individuals with greater fitness, and the error threshold. Verification for this method is provided against analytical models for the error threshold. We show that the critical mutation rate for increasing haploid population sizes can be approximated by an exponential function, with much lower mutation rates tolerated by small populations. This is in contrast to previous studies which identified that critical mutation rate was independent of population size. The algorithm is extended to diploid populations in a system modelled on the biological process of meiosis. The results confirm that the relationship remains exponential, but show that both the critical mutation rate and error threshold are lower for diploids, rather than higher as might have been expected. Analyzing the transition from critical mutation rate to error threshold provides an improved definition of critical mutation rate. Natural populations with their numbers in decline can be expected to lose genetic material in line with the exponential model, accelerating and potentially irreversibly advancing their decline, and this could potentially affect extinction, recovery and population management strategy. The effect of population size is particularly strong in small populations with 100 individuals or less; the exponential model has significant potential in aiding population management to prevent local (and global) extinction events. PMID:24386200

On the Automorphisms of a Rank One Deligne-Hitchin Moduli Space

NASA Astrophysics Data System (ADS)

Biswas, Indranil; Heller, Sebastian

2017-09-01

Let X be a compact connected Riemann surface of genus g ≥ 2, and let M_{DH} be the rank one Deligne-Hitchin moduli space associated to X. It is known that M_{DH} is the twistor space for the hyper-Kähler structure on the moduli space of rank one holomorphic connections on X. We investigate the group \\operatorname{Aut}(M_{DH}) of all holomorphic automorphisms of M_{DH}. The connected component of \\operatorname{Aut}(M_{DH}) containing the identity automorphism is computed. There is a natural element of H^2(M_{DH}, Z). We also compute the subgroup of \\operatorname{Aut}(M_{DH}) that fixes this second cohomology class. Since M_{DH} admits an ample rational curve, the notion of algebraic dimension extends to it by a theorem of Verbitsky. We prove that M_{DH} is Moishezon.

Interactions between Genetic and Ecological Effects on the Evolution of Life Cycles.

PubMed

Rescan, Marie; Lenormand, Thomas; Roze, Denis

2016-01-01

Sexual reproduction leads to an alternation between haploid and diploid phases, whose relative length varies widely across taxa. Previous genetical models showed that diploid or haploid life cycles may be favored, depending on dominance interactions and on effective recombination rates. By contrast, niche differentiation between haploids and diploids may favor biphasic life cycles, in which development occurs in both phases. In this article, we explore the interplay between genetical and ecological factors, assuming that deleterious mutations affect the competitivity of individuals within their ecological niche and allowing different effects of mutations in haploids and diploids (including antagonistic selection). We show that selection on a modifier gene affecting the relative length of both phases can be decomposed into a direct selection term favoring the phase with the highest mean fitness (due to either ecological differences or differential effects of mutations) and an indirect selection term favoring the phase in which selection is more efficient. When deleterious alleles occur at many loci and in the presence of ecological differentiation between haploids and diploids, evolutionary branching often occurs and leads to the stable coexistence of alleles coding for haploid and diploid cycles, while temporal variations in niche sizes may stabilize biphasic cycles.

Production of Androgenetic Zebrafish (Danio Rerio)

PubMed Central

Corley-Smith, G. E.; Lim, C. J.; Brandhorst, B. P.

1996-01-01

To help investigate the evolutionary origin of the imprinting (parent-of-origin mono-allelic expression) of paternal genes observed in mammals, we constructed haploid and diploid androgenetic zebrafish (Danio rerio). Haploid androgenotes were produced by fertilizing eggs that had been X-ray irradiated to eliminate the maternal genome. Subsequent inhibition of the first mitotic division of haploid androgenotes by heat shock produced diploid androgenotes. The lack of inheritance of maternal-specific DNA markers (RAPD and SSR) by putative diploid and haploid androgenotes confirmed the androgenetic origin of their genomes. Marker analysis was performed on 18 putative androgenotes (five diploids and 13 haploids) from six families. None of 157 maternal-specific RAPD markers analyzed, some of which were apparently homozygous, were passed on to any of these putative androgenotes. A mean of 7.7 maternal-specific markers were assessed per family. The survival of androgenetic zebrafish suggests that if paternal imprinting occurs in zebrafish, it does not result in essential genes being inactivated when their expression is required for development. Production of haploid androgenotes can be used to determine the meiotic recombination rate in male zebrafish. Androgenesis may also provide useful information about the mechanism of sex determination in zebrafish. PMID:8846903

Diploid, but not haploid, human embryonic stem cells can be derived from microsurgically repaired tripronuclear human zygotes

PubMed Central

Fan, Yong; Li, Rong; Huang, Jin; Yu, Yang; Qiao, Jie

2013-01-01

Human embryonic stem cells have shown tremendous potential in regenerative medicine, and the recent progress in haploid embryonic stem cells provides new insights for future applications of embryonic stem cells. Disruption of normal fertilized embryos remains controversial; thus, the development of a new source for human embryonic stem cells is important for their usefulness. Here, we investigated the feasibility of haploid and diploid embryo reconstruction and embryonic stem cell derivation using microsurgically repaired tripronuclear human zygotes. Diploid and haploid zygotes were successfully reconstructed, but a large proportion of them still had a tripolar spindle assembly. The reconstructed embryos developed to the blastocyst stage, although the loss of chromosomes was observed in these zygotes. Finally, triploid and diploid human embryonic stem cells were derived from tripronuclear and reconstructed zygotes (from which only one pronucleus was removed), but haploid human embryonic stem cells were not successfully derived from the reconstructed zygotes when two pronuclei were removed. Both triploid and diploid human embryonic stem cells showed the general characteristics of human embryonic stem cells. These results indicate that the lower embryo quality resulting from abnormal spindle assembly contributed to the failure of the haploid embryonic stem cell derivation. However, the successful derivation of diploid embryonic stem cells demonstrated that microsurgical tripronuclear zygotes are an alternative source of human embryonic stem cells. In the future, improving spindle assembly will facilitate the application of triploid zygotes to the field of haploid embryonic stem cells. PMID:23255130

Renal neuroendocrine control of desiccation and cold tolerance by Drosophila suzukii

PubMed Central

Alford, Lucy; Yeoh, Joseph GC; Marley, Richard; Dornan, Anthony J; Dow, Julian AT; Davies, Shireen A

2017-01-01

Abstract BACKGROUND Neuropeptides are central to the regulation of physiological and behavioural processes in insects, directly impacting cold and desiccation survival. However, little is known about the control mechanisms governing these responses in Drosophila suzukii. The close phylogenetic relationship of D. suzukii with Drosophila melanogaster allows, through genomic and functional studies, an insight into the mechanisms directing stress tolerance in D. suzukii. RESULTS Capability (Capa), leucokinin (LK), diuretic hormone 44 (DH44) and DH31 neuropeptides demonstrated a high level of conservation between D. suzukii and D. melanogaster with respect to peptide sequences, neuronal expression, receptor localisation, and diuretic function in the Malpighian tubules. Despite D. suzukii's ability to populate cold environments, it proved sensitive to both cold and desiccation. Furthermore, in D. suzukii, Capa acts as a desiccation‐ and cold stress‐responsive gene, while DH 44 gene expression is increased only after desiccation exposure, and the LK gene after nonlethal cold stress recovery. CONCLUSION This study provides a comparative investigation into stress tolerance mediation by neuroendocrine signalling in two Drosophila species, providing evidence that similar signalling pathways control fluid secretion in the Malpighian tubules. Identifying processes governing specific environmental stresses affecting D. suzukii could lead to the development of targeted integrated management strategies to control insect pest populations. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:28714258

iTAG Barley: A 9-12 classroom module to explore gene expression and segregation using Oregon Wolfe Barley

USDA-ARS?s Scientific Manuscript database

The Oregon Wolfe Barleys (OWBs) are a model resource for genetics research and instruction (http://barleyworld.org/oregonwolfe ; http://wheat.pw.usda.gov/ggpages/OWB_gallery/ISS-OWB/index.htm). The population of 94 doubled haploid lines was developed from an F1 of a cross between dominant and reces...

When Does Frequency-Independent Selection Maintain Genetic Variation?

PubMed

Novak, Sebastian; Barton, Nicholas H

2017-10-01

Frequency-independent selection is generally considered as a force that acts to reduce the genetic variation in evolving populations, yet rigorous arguments for this idea are scarce. When selection fluctuates in time, it is unclear whether frequency-independent selection may maintain genetic polymorphism without invoking additional mechanisms. We show that constant frequency-independent selection with arbitrary epistasis on a well-mixed haploid population eliminates genetic variation if we assume linkage equilibrium between alleles. To this end, we introduce the notion of frequency-independent selection at the level of alleles, which is sufficient to prove our claim and contains the notion of frequency-independent selection on haploids. When selection and recombination are weak but of the same order, there may be strong linkage disequilibrium; numerical calculations show that stable equilibria are highly unlikely. Using the example of a diallelic two-locus model, we then demonstrate that frequency-independent selection that fluctuates in time can maintain stable polymorphism if linkage disequilibrium changes its sign periodically. We put our findings in the context of results from the existing literature and point out those scenarios in which the possible role of frequency-independent selection in maintaining genetic variation remains unclear. Copyright © 2017 by the Genetics Society of America.

Genome size variation in the pine fusiform rust pathogen Cronartium quercuum f.sp. fusiforme as determined by flow cytometry

Treesearch

Claire L Anderson; Thomas L Kubisiak; C Dana Nelson; Jason A Smith; John M Davis

2010-01-01

The genome size of the pine fusiform rust pathogen Cronartium quercuum f.sp. fusiforme (Cqf) was determined by flow cytometric analysis of propidium iodide-stained, intact haploid pycniospores with haploid spores of two genetically well characterized fungal species, Sclerotinia sclerotiorum and Puccinia graminis f.sp. tritici, as size standards. The Cqf haploid genome...

Comparison of Different Methods for Separation of Haploid Embryo Induced through Irradiated Pollen and Their Economic Analysis in Melon (Cucumis melo var. inodorus)

PubMed Central

Baktemur, Gökhan; Taşkın, Hatıra; Büyükalaca, Saadet

2013-01-01

Irradiated pollen technique is the most successful haploidization technique within Cucurbitaceae. After harvesting of fruits pollinated with irradiated pollen, classical method called as “inspecting the seeds one by one” is used to find haploid embryos in the seeds. In this study, different methods were used to extract the embryos more easily, quickly, economically, and effectively. “Inspecting the seeds one by one” was used as control treatment. Other four methods tested were “sowing seeds direct nutrient media,” “inspecting seeds in the light source,” “floating seeds on liquid media,” and “floating seeds on liquid media after surface sterilization.” Y2 and Y3 melon genotypes selected from the third backcross population of Yuva were used as plant material. Results of this study show that there is no statistically significant difference among methods “inspecting the seeds one by one,” “sowing seeds direct CP nutrient media,” and “inspecting seeds in the light source,” although the average number of embryos per fruit is slightly different. No embryo production was obtained from liquid culture because of infection. When considered together with labor costs and time required for embryo rescue, the best methods were “sowing seeds directly in the CP nutrient media“ and ”inspecting seeds in the light source.” PMID:23818825

Dynamic hyperinflation after metronome-paced hyperventilation in COPD--a 2 year follow-up.

PubMed

Hannink, Jorien; Lahaije, Anke; Bischoff, Erik; van Helvoort, Hanneke; Dekhuijzen, Richard; Schermer, Tjard; Heijdra, Yvonne

2010-11-01

In contrast to the decline in FEV(1), the behavior of dynamic hyperinflation (DH) over time is unknown in patients with COPD. Metronome-paced hyperventilation (MPH) is a simple applicable surrogate for exercise to detect DH. To evaluate changes in MPH-induced DH during two years follow-up in mild-to-severe COPD patients. Additionally, influence of smoking status on DH and the relation between DH and other lung function parameters were assessed. Patients were recruited from a randomized controlled trial conducted in general practice. Measurements of lung function and DH were performed at baseline and after 12 and 24 months. DH was assessed by MPH with breathing frequency set at twice the baseline rate. Change in inspiratory capacity after MPH was used to reflect change in end-expiratory lung volume and therefore DH, presuming constant total lung capacity. During follow-up, 68 patients completed all measurements. DH increased by 0.23±0.06L (p≤0.001). No significant changes in FEV(1) %pred were seen. Smokers had lower FEV(1) and a more rapid decline than non-smokers. DH in smokers increased more over time compared to non-smokers. The amount of DH correlated positively with resting inspiratory capacity. After two years, a significant increase in MPH-induced DH in COPD patients was demonstrated, which was not accompanied by a decline in FEV(1). It might be that DH is a sensitive measure to track consequences of changes in airflow obstruction. Copyright © 2010 Elsevier Ltd. All rights reserved.

The evolution of sex chromosomes in organisms with separate haploid sexes.

PubMed

Immler, Simone; Otto, Sarah Perin

2015-03-01

The evolution of dimorphic sex chromosomes is driven largely by the evolution of reduced recombination and the subsequent accumulation of deleterious mutations. Although these processes are increasingly well understood in diploid organisms, the evolution of dimorphic sex chromosomes in haploid organisms (U/V) has been virtually unstudied theoretically. We analyze a model to investigate the evolution of linkage between fitness loci and the sex-determining region in U/V species. In a second step, we test how prone nonrecombining regions are to degeneration due to accumulation of deleterious mutations. Our modeling predicts that the decay of recombination on the sex chromosomes and the addition of strata via fusions will be just as much a part of the evolution of haploid sex chromosomes as in diploid sex chromosome systems. Reduced recombination is broadly favored, as long as there is some fitness difference between haploid males and females. The degeneration of the sex-determining region due to the accumulation of deleterious mutations is expected to be slower in haploid organisms because of the absence of masking. Nevertheless, balancing selection often drives greater differentiation between the U/V sex chromosomes than in X/Y and Z/W systems. We summarize empirical evidence for haploid sex chromosome evolution and discuss our predictions in light of these findings. © 2015 The Author(s).

The Histone Deacetylase Inhibitor Trichostatin A Promotes Totipotency in the Male Gametophyte[W

PubMed Central

Li, Hui; Soriano, Mercedes; Cordewener, Jan; Muiño, Jose M.; Riksen, Tjitske; Fukuoka, Hiroyuki; Angenent, Gerco C.; Boutilier, Kim

2014-01-01

The haploid male gametophyte, the pollen grain, is a terminally differentiated structure whose function ends at fertilization. Plant breeding and propagation widely use haploid embryo production from in vitro–cultured male gametophytes, but this technique remains poorly understood at the mechanistic level. Here, we show that histone deacetylases (HDACs) regulate the switch to haploid embryogenesis. Blocking HDAC activity with trichostatin A (TSA) in cultured male gametophytes of Brassica napus leads to a large increase in the proportion of cells that switch from pollen to embryogenic growth. Embryogenic growth is enhanced by, but not dependent on, the high-temperature stress that is normally used to induce haploid embryogenesis in B. napus. The male gametophyte of Arabidopsis thaliana, which is recalcitrant to haploid embryo development in culture, also forms embryogenic cell clusters after TSA treatment. Genetic analysis suggests that the HDAC protein HDA17 plays a role in this process. TSA treatment of male gametophytes is associated with the hyperacetylation of histones H3 and H4. We propose that the totipotency of the male gametophyte is kept in check by an HDAC-dependent mechanism and that the stress treatments used to induce haploid embryo development in culture impinge on this HDAC-dependent pathway. PMID:24464291

Unravelling the distinct strains of Tharu ancestry

PubMed Central

Chaubey, Gyaneshwer; Singh, Manvendra; Crivellaro, Federica; Tamang, Rakesh; Nandan, Amrita; Singh, Kamayani; Sharma, Varun Kumar; Pathak, Ajai Kumar; Shah, Anish M; Sharma, Vishwas; Singh, Vipin Kumar; Selvi Rani, Deepa; Rai, Niraj; Kushniarevich, Alena; Ilumäe, Anne-Mai; Karmin, Monika; Phillip, Anand; Verma, Abhilasha; Prank, Erik; Singh, Vijay Kumar; Li, Blaise; Govindaraj, Periyasamy; Chaubey, Akhilesh Kumar; Dubey, Pavan Kumar; Reddy, Alla G; Premkumar, Kumpati; Vishnupriya, Satti; Pande, Veena; Parik, Jüri; Rootsi, Siiri; Endicott, Phillip; Metspalu, Mait; Lahr, Marta Mirazon; van Driem, George; Villems, Richard; Kivisild, Toomas; Singh, Lalji; Thangaraj, Kumarasamy

2014-01-01

The northern region of the Indian subcontinent is a vast landscape interlaced by diverse ecologies, for example, the Gangetic Plain and the Himalayas. A great number of ethnic groups are found there, displaying a multitude of languages and cultures. The Tharu is one of the largest and most linguistically diverse of such groups, scattered across the Tarai region of Nepal and bordering Indian states. Their origins are uncertain. Hypotheses have been advanced postulating shared ancestry with Austroasiatic, or Tibeto-Burman-speaking populations as well as aboriginal roots in the Tarai. Several Tharu groups speak a variety of Indo-Aryan languages, but have traditionally been described by ethnographers as representing East Asian phenotype. Their ancestry and intra-population diversity has previously been tested only for haploid (mitochondrial DNA and Y-chromosome) markers in a small portion of the population. This study presents the first systematic genetic survey of the Tharu from both Nepal and two Indian states of Uttarakhand and Uttar Pradesh, using genome-wide SNPs and haploid markers. We show that the Tharu have dual genetic ancestry as up to one-half of their gene pool is of East Asian origin. Within the South Asian proportion of the Tharu genetic ancestry, we see vestiges of their common origin in the north of the South Asian Subcontinent manifested by mitochondrial DNA haplogroup M43. PMID:24667789

The first genetic map of a synthesized allohexaploid Brassica with A, B and C genomes based on simple sequence repeat markers.

PubMed

Yang, S; Chen, S; Geng, X X; Yan, G; Li, Z Y; Meng, J L; Cowling, W A; Zhou, W J

2016-04-01

We present the first genetic map of an allohexaploid Brassica species, based on segregating microsatellite markers in a doubled haploid mapping population generated from a hybrid between two hexaploid parents. This study reports the first genetic map of trigenomic Brassica. A doubled haploid mapping population consisting of 189 lines was obtained via microspore culture from a hybrid H16-1 derived from a cross between two allohexaploid Brassica lines (7H170-1 and Y54-2). Simple sequence repeat primer pairs specific to the A genome (107), B genome (44) and C genome (109) were used to construct a genetic linkage map of the population. Twenty-seven linkage groups were resolved from 274 polymorphic loci on the A genome (109), B genome (49) and C genome (116) covering a total genetic distance of 3178.8 cM with an average distance between markers of 11.60 cM. This is the first genetic framework map for the artificially synthesized Brassica allohexaploids. The linkage groups represent the expected complement of chromosomes in the A, B and C genomes from the original diploid and tetraploid parents. This framework linkage map will be valuable for QTL analysis and future genetic improvement of a new allohexaploid Brassica species, and in improving our understanding of the genetic control of meiosis in new polyploids.

Development of visual field defect after first-detected optic disc hemorrhage in preperimetric open-angle glaucoma.

PubMed

Kim, Hae Jin; Song, Yong Ju; Kim, Young Kook; Jeoung, Jin Wook; Park, Ki Ho

2017-07-01

To evaluate functional progression in preperimetric glaucoma (PPG) with disc hemorrhage (DH) and to determine the time interval between the first-detected DH and development of glaucomatous visual field (VF) defect. A total of 87 patients who had been first diagnosed with PPG were enrolled. The medical records of PPG patients without DH (Group 1) and with DH (Group 2) were reviewed. When glaucomatous VF defect appeared, the time interval from the diagnosis of PPG to the development of VF defect was calculated and compared between the two groups. In group 2, the time intervals from the first-detected DH to VF defect of the single- and recurrent-DH were compared. Of the enrolled patients, 45 had DH in the preperimetric stage. The median time interval from the diagnosis of PPG to the development of VF defect was 73.3 months in Group 1, versus 45.4 months in Group 2 (P = 0.042). The cumulative probability of development of VF defect after diagnosis of PPG was significantly greater in Group 2 than in Group 1. The median time interval from first-detected DH to the development of VF defect was 37.8 months. The median time interval from DH to VF defect and cumulative probability of VF defect after DH did not show a statistical difference between single and recurrent-DH patients. The median time interval between the diagnosis of PPG and the development of VF defect was significantly shorter in PPG with DH. The VF defect appeared 37.8 months after the first-detected DH in PPG.

Quantitative trait loci mapping of western corn rootworm (Coleoptera: Chrysomelidae) host plant resistance in two populations of doubled haploid lines in maize (Zea mays L.)

USDA-ARS?s Scientific Manuscript database

Over the last 70 years, more than 12,000 maize accessions have been screened for their level of resistance to western corn rootworm, Diabrotica virgifera virgifera LeConte, larval feeding. Less than 1% of this germplasm was selected for initiating recurrent selection or other breeding programs. Sele...

Gametocidal Factor Transferred from Aegilops geniculata Roth Can Be Adapted for Large-Scale Chromosome Manipulations in Cereals

PubMed Central

Kwiatek, Michał T.; Wiśniewska, Halina; Ślusarkiewicz-Jarzina, Aurelia; Majka, Joanna; Majka, Maciej; Belter, Jolanta; Pudelska, Hanna

2017-01-01

Segregation distorters are curious, evolutionarily selfish genetic elements, which distort Mendelian segregation in their favor at the expense of others. Those agents include gametocidal factors (Gc), which ensure their preferential transmission by triggering damages in cells lacking them via chromosome break induction. Hence, we hypothesized that the gametocidal system can be adapted for chromosome manipulations between Triticum and Secale chromosomes in hexaploid triticale (×Triticosecale Wittmack). In this work we studied the little-known gametocidal action of a Gc factor located on Aegilops geniculata Roth chromosome 4Mg. Our results indicate that the initiation of the gametocidal action takes place at anaphase II of meiosis of pollen mother cells. Hence, we induced androgenesis at postmeiotic pollen divisions (via anther cultures) in monosomic 4Mg addition plants of hexaploid triticale (AABBRR) followed by production of doubled haploids, to maintain the chromosome aberrations caused by the gametocidal action. This approach enabled us to obtain a large number of plants with two copies of particular chromosome translocations, which were identified by the use of cytomolecular methods. We obtained 41 doubled haploid triticale lines and 17 of them carried chromosome aberrations that included plants with the following chromosome sets: 40T+Dt2RS+Dt2RL (5 lines), 40T+N2R (1), 38T+D4RS.4BL (3), 38T+D5BS-5BL.5RL (5), and 38T+D7RS.3AL (3). The results show that the application of the Gc mechanism in combination with production of doubled haploid lines provides a sufficiently large population of homozygous doubled haploid individuals with two identical copies of translocation chromosomes. In our opinion, this approach will be a valuable tool for the production of novel plant material, which could be used for gene tracking studies, genetic mapping, and finally to enhance the diversity of cereals. PMID:28396677

Oral Administration of TAT-PTD-Diapause Hormone Fusion Protein Interferes With Helicoverpa armigera (Lepidoptera: Noctuidae) Development.

PubMed

Zhou, Zhou; Li, Yongli; Yuan, Chunyan; Zhang, Yongan; Qu, Liangjian

2015-01-01

Diapause hormone (DH), which can terminate diapause in Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), has shown promise as a pest control method. However, the main challenge in using DH as an insecticide lies in achieving effective oral delivery, since the peptide may be degraded by digestive enzymes in the gut. To improve the efficacy of oral DH application, the Clostera anastomosis (L.) (Lepidoptera: Notodontidae) diapause hormone (caDH) was fused to the Protein Transduction Domain (PTD) of the human immunodeficiency virus-1 transactivator of transcription (TAT). Cellular transduction of TAT-caDH was verified with the use of a green fluorescent protein fusion, and its ability to terminate diapause was verified by injection into diapausing H. armigera pupae. Orally administered TAT-caDH resulted in larval growth inhibition. In TAT-caDH-treated insects, larval duration was delayed and the pupation rates were decreased at both development promoting conditions [27 °C, a photoperiod of 14:10(L:D) h] and diapause inducing conditions [20 °C, a photoperiod of 10:14(L:D) h]. No significant difference in diapause rate was observed between the TAT-caDH-treated and caDH-treated or control pupae maintained at diapause inducing conditions. Our results show that treatment with a recombinant TAT-caDH protein can affect larval development in H. armigera, and it suggest that TAT-DH treatment may be useful for controlling pests. This study is the first record of oral DH application in insect. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Adaptation and major chromosomal changes in populations of Saccharomyces cerevisiae.

PubMed

Adams, J; Puskas-Rozsa, S; Simlar, J; Wilke, C M

1992-07-01

Thirteen independent populations of Saccharomyces cerevisiae (nine haploid and four diploid) were maintained in continuous culture for up to approximately 1000 generations, with growth limited by the concentration of organic phosphates in medium buffered at pH 6. Analysis of clones isolated from these populations showed that a number (17) of large-scale chromosomal-length variants and rearrangements were present in the populations at their termination. Nine of the 16 yeast chromosomes were involved in such changes. Few of the changes could be explained by copy-number increases in the structural loci for acid phosphatase. Several considerations concerning the nature and frequency of the chromosome-length variants observed lead us to conclude that they are selectively advantageous.

Self-Reported Fractures in Dermatitis Herpetiformis Compared to Coeliac Disease

PubMed Central

Pasternack, Camilla; Mansikka, Eriika; Kaukinen, Katri; Hervonen, Kaisa; Reunala, Timo; Collin, Pekka; Mattila, Ville M.

2018-01-01

Dermatitis herpetiformis (DH) is a cutaneous manifestation of coeliac disease. Increased bone fracture risk is known to associate with coeliac disease, but this has been only scantly studied in DH. In this study, self-reported fractures and fracture-associated factors in DH were investigated and compared to coeliac disease. Altogether, 222 DH patients and 129 coeliac disease-suffering controls were enrolled in this study. The Disease Related Questionnaire and the Gastrointestinal Symptom Rating Scale and Psychological General Well-Being questionnaires were mailed to participants; 45 out of 222 (20%) DH patients and 35 out of 129 (27%) of the coeliac disease controls had experienced at least one fracture (p = 0.140). The cumulative lifetime fracture incidence did not differ between DH and coeliac disease patients, but the cumulative incidence of fractures after diagnosis was statistically significantly higher in females with coeliac disease compared to females with DH. The DH patients and the coeliac disease controls with fractures reported more severe reflux symptoms compared to those without, and they also more frequently used proton-pump inhibitor medication. To conclude, the self-reported lifetime bone fracture risk is equal for DH and coeliac disease. After diagnosis, females with coeliac disease have a higher fracture risk than females with DH. PMID:29538319

Characteristics explaining performance in downhill mountain biking.

PubMed

Chidley, Joel B; MacGregor, Alexandra L; Martin, Caoimhe; Arthur, Calum A; Macdonald, Jamie H

2015-03-01

To identify physiological, psychological, and skill characteristics that explain performance in downhill (DH) mountain-bike racing. Four studies were used to (1) identify factors potentially contributing to DH performance (using an expert focus group), (2) develop and validate a measure of rider skill (using video analysis and expert judge evaluation), (3) evaluate whether physiological, psychological, and skill variables contribute to performance at a DH competition, and (4) test the specific contribution of aerobic capacity to DH performance. STUDY 1 identified aerobic capacity, handgrip endurance, anaerobic power, rider skill, and self-confidence as potentially important for DH. In study 2 the rider-skill measure displayed good interrater reliability. Study 3 found that rider skill and handgrip endurance were significantly related to DH ride time (β=-0.76 and -0.14, respectively; R2=.73), with exploratory analyses suggesting that DH ride time may also be influenced by self-confidence and aerobic capacity. Study 4 confirmed aerobic capacity as an important variable influencing DH performance (for a DH ride, mean oxygen uptake was 49±5 mL·kg(-1)·min(-1), and 90% of the ride was completed above the 1st ventilatory threshold). In order of importance, rider skill, handgrip endurance, self-confidence, and aerobic capacity were identified as variables influencing DH performance. Practically, this study provides a novel assessment of rider skill that could be used by coaches to monitor training and identify talent. Novel intervention targets to enhance DH performance were also identified, including self-confidence and aerobic capacity.

CHPA, a Cysteine- and Histidine-Rich-Domain-Containing Protein, Contributes to Maintenance of the Diploid State in Aspergillus nidulans

PubMed Central

Sadanandom, Ari; Findlay, Kim; Doonan, John H.; Schulze-Lefert, Paul; Shirasu, Ken

2004-01-01

The alternation of eukaryotic life cycles between haploid and diploid phases is crucial for maintaining genetic diversity. In some organisms, the growth and development of haploid and diploid phases are nearly identical, and one might suppose that all genes required for one phase are likely to be critical for the other phase. Here, we show that targeted disruption of the chpA (cysteine- and histidine-rich-domain- [CHORD]-containing protein A) gene in haploid Aspergillus nidulans strains gives rise to chpA knockout haploids and heterozygous diploids but no chpA knockout diploids. A. nidulans chpA heterozygous diploids showed impaired conidiophore development and reduced conidiation. Deletion of chpA from diploid A. nidulans resulted in genome instability and reversion to a haploid state. Thus, our data suggest a vital role for chpA in maintenance of the diploid phase in A. nidulans. Furthermore, the human chpA homolog, Chp-1, was able to complement haploinsufficiency in A. nidulans chpA heterozygotes, suggesting that the function of CHORD-containing proteins is highly conserved in eukaryotes. PMID:15302831

An Upper Limit on the Mass of the Circumplanetary Disk for DH Tau b

NASA Astrophysics Data System (ADS)

Wolff, Schuyler G.; Ménard, François; Caceres, Claudio; Lefèvre, Charlene; Bonnefoy, Mickael; Cánovas, Héctor; Maret, Sébastien; Pinte, Christophe; Schreiber, Matthias R.; van der Plas, Gerrit

2017-07-01

DH Tau is a young (˜1 Myr) classical T Tauri star. It is one of the few young PMS stars known to be associated with a planetary mass companion, DH Tau b, orbiting at large separation and detected by direct imaging. DH Tau b is thought to be accreting based on copious {{H}}α emission and exhibits variable Paschen Beta emission. NOEMA observations at 230 GHz allow us to place constraints on the disk dust mass for both DH Tau b and the primary in a regime where the disks will appear optically thin. We estimate a disk dust mass for the primary, DH Tau A of 17.2+/- 1.7 {M}\\oplus , which gives a disk to star mass ratio of 0.014 (assuming the usual gas to dust mass ratio of 100 in the disk). We find a conservative disk dust mass upper limit of 0.42 M ⊕ for DH Tau b, assuming that the disk temperature is dominated by irradiation from DH Tau b itself. Given the environment of the circumplanetary disk, variable illumination from the primary or the equilibrium temperature of the surrounding cloud would lead to even lower disk mass estimates. A MCFOST radiative transfer model, including heating of the circumplanetary disk by DH Tau b and DH Tau A, suggests that a mass-averaged disk temperature of 22 K is more realistic, resulting in a dust disk mass upper limit of 0.09 M ⊕ for DH Tau b. We place DH Tau b in context with similar objects and discuss the consequences for planet formation models. This work is based on observations carried out under project D15AC with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

Biosynthesis, Characterization, and Bioactivities Evaluation of Silver and Gold Nanoparticles Mediated by the Roots of Chinese Herbal Angelica pubescens Maxim

NASA Astrophysics Data System (ADS)

Markus, Josua; Wang, Dandan; Kim, Yeon-Ju; Ahn, Sungeun; Mathiyalagan, Ramya; Wang, Chao; Yang, Deok Chun

2017-01-01

A facile synthesis and biological applications of silver (DH-AgNps) and gold nanoparticles (DH-AuNps) mediated by the aqueous extract of Angelicae Pubescentis Radix (Du Huo) are explored. Du Huo is a medicinal root belonging to Angelica pubescens Maxim which possesses anti-inflammatory, analgesic, and antioxidant properties. The absorption spectra of nanoparticles in varying root extract and metal ion concentration, pH, reaction temperatures, and time were recorded by ultraviolet-visible (UV-Vis) spectroscopy. The presence of DH-AgNps and DH-AuNps was confirmed from the surface plasmon resonance intensified at 414 and 540 nm, respectively. Field emission transmission electron micrograph (FE-TEM) analysis revealed the formation of quasi-spherical DH-AgNps and spherical icosahedral DH-AuNps. These novel DH-AgNps and DH-AuNps maintained an average crystallite size of 12.48 and 7.44 nm, respectively. The biosynthesized DH-AgNps and DH-AuNps exhibited antioxidant activity against 2,2-diphenyl-1-picrylhydrzyl (DPPH) radicals and the former exhibited antimicrobial activity against clinical pathogens including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica. The expected presence of flavonoids, sesquiterpenes, and phenols on the nanoparticle surface were conjectured to grant protection against aggregation and free radical scavenging activity. DH-AgNps and DH-AuNps were further investigated for their cytotoxic properties in RAW264.7 macrophages for their potential application as drug carriers to sites of inflammation. In conclusion, this green synthesis is favorable for the advancement of plant mediated nano-carriers in drug delivery systems, cancer diagnostic, and medical imaging.

Exact Markov chain and approximate diffusion solution for haploid genetic drift with one-way mutation.

PubMed

Hössjer, Ola; Tyvand, Peder A; Miloh, Touvia

2016-02-01

The classical Kimura solution of the diffusion equation is investigated for a haploid random mating (Wright-Fisher) model, with one-way mutations and initial-value specified by the founder population. The validity of the transient diffusion solution is checked by exact Markov chain computations, using a Jordan decomposition of the transition matrix. The conclusion is that the one-way diffusion model mostly works well, although the rate of convergence depends on the initial allele frequency and the mutation rate. The diffusion approximation is poor for mutation rates so low that the non-fixation boundary is regular. When this happens we perturb the diffusion solution around the non-fixation boundary and obtain a more accurate approximation that takes quasi-fixation of the mutant allele into account. The main application is to quantify how fast a specific genetic variant of the infinite alleles model is lost. We also discuss extensions of the quasi-fixation approach to other models with small mutation rates. Copyright © 2015 Elsevier Inc. All rights reserved.

Saving the Predators: Teaching About the Role of Predatory Animals.

ERIC Educational Resources Information Center

Soltow, Willow

1985-01-01

Discusses the role of predators in regulating prey populations, noting that this is an excellent example of the "interconnectedness" of life. Suggestions for films, books, articles, and student questions are given, and a special section dealing with human attitudes about predators is provided. (DH)

The corticotropin-releasing factor-like diuretic hormone 44 (DH44) and kinin neuropeptides modulate desiccation and starvation tolerance in Drosophila melanogaster.

PubMed

Cannell, Elizabeth; Dornan, Anthony J; Halberg, Kenneth A; Terhzaz, Selim; Dow, Julian A T; Davies, Shireen-A

2016-06-01

Malpighian tubules are critical organs for epithelial fluid transport and stress tolerance in insects, and are under neuroendocrine control by multiple neuropeptides secreted by identified neurons. Here, we demonstrate roles for CRF-like diuretic hormone 44 (DH44) and Drosophila melanogaster kinin (Drome-kinin, DK) in desiccation and starvation tolerance. Gene expression and labelled DH44 ligand binding data, as well as highly selective knockdowns and/or neuronal ablations of DH44 in neurons of the pars intercerebralis and DH44 receptor (DH44-R2) in Malpighian tubule principal cells, indicate that suppression of DH44 signalling improves desiccation tolerance of the intact fly. Drome-kinin receptor, encoded by the leucokinin receptor gene, LKR, is expressed in DH44 neurons as well as in stellate cells of the Malpighian tubules. LKR knockdown in DH44-expressing neurons reduces Malpighian tubule-specific LKR, suggesting interactions between DH44 and LK signalling pathways. Finally, although a role for DK in desiccation tolerance was not defined, we demonstrate a novel role for Malpighian tubule cell-specific LKR in starvation tolerance. Starvation increases gene expression of epithelial LKR. Also, Malpighian tubule stellate cell-specific knockdown of LKR significantly reduced starvation tolerance, demonstrating a role for neuropeptide signalling during starvation stress. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Relationship between the energy levels and the photovoltaic properties of oligothiophenes.

PubMed

Lim, Eunhee

2014-08-01

A series of linear π-conjugated oligothiophenes, α,α'-dihexylquinquethiophene (DH5T), 2,5-bis(5'-hexyl-2,2'-bithiophene-5-yl)thieno[3,2-b]thiophene (DH5TT), and α,α'-dihexylheptathiophene (DH7T), has been synthesized using the Suzuki coupling reaction. The optical and electrochemical properties of oligothiophenes were easily tuned by controlling the thiophene number. The UV-vis absorption and photoluminescence (PL) spectra are gradually red-shifted on going from DH5T and DH5TT to DH7T due to the increase in α-conjugation length. The energy band gap decreased as the oligothiophene length increased. The optical band gaps of DH5T, DH5TT, and DH7T occur at 2.39, 2.25, and 2.01 eV, respectively. Bulk heterojunction organic photovoltaic cells (OPVs) fabricated from oligomers showed the power conversion efficiency of 0.45-0.8% under AM 1.5 (100 mW/cm2). Among them, DH5T showed the best OPV performance of an open circuit voltage (VOC) of 0.51 V, short-circuit current (JSC) of 4.25 mA/cm2, and fill factor (FF) of 0.37, resulting in the power conversion efficiency of 0.80%. Moreover, the relationship between conjugation length and photovoltaic properties was systematically investigated in terms of the energy band gap and open circuit voltage (VOC).

Resolution Mechanism and Characterization of an Ammonium Chloride-Tolerant, High-Thermostable, and Salt-Tolerant Phenylalanine Dehydrogenase from Bacillus halodurans.

PubMed

Jiang, Wei; Wang, Ya-Li; Fang, Bai-Shan

2018-05-09

As phenylalanine dehydrogenase (PheDH) plays an important role in the synthesis of chiral drug intermediates and detection of phenylketonuria, it is significant to obtain a PheDH with specific and high activity. Here, a PheDH gene, pdh, encoding a novel BhPheDH with 61.0% similarity to the known PheDH from Microbacterium sp., was obtained. The BhPheDH showed optimal activity at 60 °C and pH 7.0, and it showed better stability in hot environment (40-70 °C) than the PheDH from Nocardia sp. And its activity and thermostability could be significantly increased by sodium salt. After incubation for 2 h in 3 M NaCl at 60 °C, the residual activity of the BhPheDH was found to be 1.8-fold higher than that of the control group (without NaCl). The BhPheDH could tolerate high concentration of ammonium chloride and its activity could be also enhanced by the high concentration of ammonium salts. These characteristics indicate that the BhPheDH possesses better thermostability, ammonium chloride tolerance, halophilic mechanism, and high salt activation. The mechanism of thermostability and high salt tolerance of the BhPheDH was analyzed by molecular dynamics simulation. These results provide useful information about the enzyme with high-temperature activity, thermostability, halophilic mechanism, tolerance to high concentration of ammonium chloride, higher salt activation and enantio-selectivity, and the application of molecular dynamics simulation in analyzing the mechanism of these distinctive characteristics.

End-of-life care in lung cancer patients in Ontario: aggressiveness of care in the population and a description of hospital admissions.

PubMed

Barbera, Lisa; Paszat, Lawrence; Qiu, Feng

2008-03-01

The purpose of this study was to describe (1) the aggressiveness of care in a population of patients who die of lung cancer and (2) differences in care between a sample of lung cancer patients who died in an acute care hospital (DH) and a sample of lung cancer patients who were admitted to hospital during the last six months of life but were discharged and died elsewhere (DO). All lung cancer deaths in 2002 were identified in the provincial registry. Cases were linked to administrative sources of health care data to describe the population as a whole and the aggressiveness of the care that they received. Primary data were collected from a province-wide sample of patients' hospital charts focusing on reasons for admission, care in hospital, advanced planning, pain, and disposition. In total, 5,855 patients who died of lung cancer in 2002 were eligible for inclusion in the cohort. Rates of in-hospital death, emergency room visits, intensive care unit admissions, and chemotherapy use near the end of life were 59.5%, 32.2%, 5.5%, and 4.6%, respectively. The records of 491 patients were abstracted for this study. The DH and DO groups were similar with respect to age, gender, neighborhood income level, and extent of metastatic disease. The most common chief complaints were shortness of breath, pain, inability to cope at home, and altered level of consciousness. Compared to patients in the DO group, those in the DH group presented with pain more often (19% vs. 10%, P<0.005) and were more likely to be admitted with progressive chest malignancy (30% vs. 21%, P<0.05). Regardless of reason for admission, pain was commonly documented as a problem during admission: 73.5% in the DH group and 62.4% in the DO group (P<0.05). Lung cancer patients are heavy users of acute care beds and the emergency room at the end of life. Those who do or do not die in hospital are similar in many respects but our results suggest those dying in hospital have more problems with pain and burden from local chest malignancy.

Bench Crater Meteorite: Hydrated Asteroidal Material Delivered to the Moon

NASA Technical Reports Server (NTRS)

Joy, K. H.; Messenger, S.; Zolensky, M. E.; Frank, D. R.; Kring, D. A.

2013-01-01

D/H measurements from the lunar regolith agglutinates [8] indicate mixing between a low D/H solar implanted component and additional higher D/H sources (e.g., meteoritic/ cometary/volcanic gases). We have determined the range and average D/H ratio of Bench Crater meteorite, which is the first direct D/H analysis of meteoritic material delivered to the lunar surface. This result provides an important ground truth for future investigations of lunar water resources by missions to the Moon.

Dominant hemimelia and En-1 on mouse chromosome 1 are not allelic.

PubMed

Higgins, M; Hill, R E; West, J D

1992-08-01

Previous studies have shown that En-1, a homeobox-containing gene, maps close to or at the Dh locus in the mouse. Since homeobox-containing genes are key genes in the control of development the close proximity of En-1 to the developmentally significant gene Dh raised the possibility that the Dh mutation represented a mutant allele of En-1. A genetic analysis involving En-1, Dh, and other chromosome 1 markers (Emv-17, ln and Pep-3) shows that although Dh and En-1 are closely linked they are separable by recombination (4/563). The likely gene order and recombination frequencies of these loci are: ln (5.2 +/- 0.9) Emv-17 (1.1 +/- 0.4) Dh (0.7 +/- 0.4) En-1 (3.0 +/- 0.7) Pep-3. This shows that Dh is not a mutant allele of En-1.

Determination of dopamine hydrochloride by host-guest interaction based on water-soluble pillar[5]arene

NASA Astrophysics Data System (ADS)

Xiao, Xue-Dong; Shi, Lin; Guo, Li-Hui; Wang, Jun-Wen; Zhang, Xiang

2017-02-01

The supramolecular interaction between the water-soluble pillar[5]arene (WP[5]) as host and dopamine hydrochloride (DH) as guest was studied by spectrofluorometry. The fluorescence intensity of DH gradually decreased with increasing WP[5] concentration, and the possible interaction mechanism between WP[5] and DH was confirmed by 1H NMR, 2D NOESY, and molecular modelling. Based on significant DH fluorescence, a highly sensitive and selective method for DH determination was developed for the first time. The fluorescence intensity was measured at 312 nm, with excitation at 285 nm. The effects of pH, temperature, and reaction time on the fluorescence spectra of the WP[5]-DH complex were investigated. A linear relationship between fluorescence intensity and DH concentration in the range of 0.07-6.2 μg mL- 1 was obtained. The corresponding linear regression equation is ΔF = 25.76 C + 13.56 (where C denotes the concentration in μg mL- 1), with the limit of detection equal to 0.03 μg mL- 1 and the correlation coefficient equal to 0.9996. This method can be used for the determination of dopamine in injection and urine samples. In addition, the WP[5]-DH complex has potential applications in fluorescent sensing and pharmacokinetics studies of DH.

Management of Dentin Hypersensitivity by National Dental Practice-Based Research Network practitioners: results from a questionnaire administered prior to initiation of a clinical study on this topic.

PubMed

Kopycka-Kedzierawski, Dorota T; Meyerowitz, Cyril; Litaker, Mark S; Chonowski, Sidney; Heft, Marc W; Gordan, Valeria V; Yardic, Robin L; Madden, Theresa E; Reyes, Stephanie C; Gilbert, Gregg H

2017-01-13

Dentin hypersensitivity (DH) is a common problem encountered in clinical practice. The purpose of this study was to identify the management approaches for DH among United States dentists. One hundred eighty five National Dental Practice-Based Research Network clinicians completed a questionnaire regarding their preferred methods to diagnose and manage DH in the practice setting, and their beliefs about DH predisposing factors. Almost all dentists (99%) reported using more than one method to diagnose DH. Most frequently, they reported using spontaneous patient reports coupled with excluding other causes of oral pain by direct clinical examination (48%); followed by applying an air blast (26%), applying cold water (12%), and obtaining patient reports after dentist's query (6%). In managing DH, the most frequent first choice was desensitizing, over-the-counter (OTC), potassium nitrate toothpaste (48%), followed by fluorides (38%), and glutaraldehyde/HEMA (3%). A total of 86% of respondents reported using a combination of products when treating DH, most frequently using fluoride varnish and desensitizing OTC potassium nitrate toothpaste (70%). The most frequent predisposing factor leading to DH, as reported by the practitioners, was recessed gingiva (66%), followed by abrasion, erosion, abfraction/attrition lesions (59%) and bruxism (32%). The majority of network practitioners use multiple methods to diagnose and manage DH. Desensitizing OTC potassium nitrate toothpaste and fluoride formulations are the most widely used products to manage DH in dental practice setting.

The Multifaceted Effects of Polysaccharides Isolated from Dendrobium huoshanense on Immune Functions with the Induction of Interleukin-1 Receptor Antagonist (IL-1ra) in Monocytes

PubMed Central

Lin, Juway; Chang, Ya-Jen; Yang, Wen-Bin; Yu, Alice L.; Wong, Chi-Huey

2014-01-01

Dendrobium huoshanense is a valuable and versatile Chinese herbal medicine with the anecdotal claims of cancer prevention and anti-inflammation. However, its immunological activities are limited to in vitro studies on a few cytokines and immune cell functions. First, we investigated the effects of polysaccharides isolated from DH (DH-PS) on inducing a panel of cytokines/chemokines in mice in vivo and human in vitro. We found that DH polysaccharides (DH-PS) induced TH1, TH2, inflammatory cytokines and chemokines in mouse in vivo and human cells in vitro. Secondly, we demonstrated that DH-PS expanded mouse splenocytes in vivo including CD4+ T cells, CD8+ T cells, B cells, NK cells, NKT cells, monocytes/macrophages, granulocytes and regulatory T cells. Notably, DH-PS induced an anti-inflammatory molecule, IL-1ra, in mouse and human immune cells, especially monocytes. The serum level of IL-1ra elicited by the injection of DH-PS was over 10 folds of IL-1β, suggesting that DH-PS-induced anti-inflammatory activities might over-ride the inflammatory ones mediated by IL-1β. The signaling pathways of DH-PS-induced IL-1ra production was shown to involve ERK/ELK, p38 MAPK, PI3K and NFκB. Finally, we observed that IL-1ra level induced by DH-PS was significantly higher than that by F3, a polysaccharide extract isolated from another popular Chinese herbal medicine, Ganoderma lucidum. These results indicated that DH-PS might have potential applications for ameliorating IL-1-induced pathogenic conditions. PMID:24705413

Crystal structure of the NADP+ and tartrate-bound complex of L-serine 3-dehydrogenase from the hyperthermophilic archaeon Pyrobaculum calidifontis.

PubMed

Yoneda, Kazunari; Sakuraba, Haruhiko; Araki, Tomohiro; Ohshima, Toshihisa

2018-05-01

A gene encoding L-serine dehydrogenase (L-SerDH) that exhibits extremely low sequence identity to the Agrobacterium tumefaciens L-SerDH was identified in the hyperthermophilic archaeon Pyrobaculum calidifontis. The predicted amino acid sequence showed 36% identity with that of Pseudomonas aeruginosa L-SerDH, suggesting that P. calidifontis L-SerDH is a novel type of L-SerDH, like Ps. aeruginosa L-SerDH. The overexpressed enzyme appears to be the most thermostable L-SerDH described to date, and no loss of activity was observed by incubation for 30 min at temperatures up to 100 °C. The enzyme showed substantial reactivity towards D-serine, in addition to L-serine. Two different crystal structures of P. calidifontis L-SerDH were determined using the Se-MAD and MR method: the structure in complex with NADP + /sulfate ion at 1.18 Å and the structure in complex with NADP + /L-tartrate (substrate analog) at 1.57 Å. The fold of the catalytic domain showed similarity with that of Ps. aeruginosa L-SerDH. However, the active site structure significantly differed between the two enzymes. Based on the structure of the tartrate, L- and D-serine and 3-hydroxypropionate molecules were modeled into the active site and the substrate binding modes were estimated. A structural comparison suggests that the wide cavity at the substrate binding site is likely responsible for the high reactivity of the enzyme toward both L- and D-serine enantiomers. This is the first description of the structure of the novel type of L-SerDH with bound NADP + and substrate analog, and it provides new insight into the substrate binding mechanism of L-SerDH. The results obtained here may be very informative for the creation of L- or D-serine-specific SerDH by protein engineering.

Marker Exchange Mutagenesis of mxaF, Encoding the Large Subunit of the Mxa Methanol Dehydrogenase, in Methylosinus trichosporium OB3b

PubMed Central

Farhan Ul Haque, Muhammad; Gu, Wenyu; DiSpirito, Alan A.

2015-01-01

Methanotrophs have remarkable redundancy in multiple steps of the central pathway of methane oxidation to carbon dioxide. For example, it has been known for over 30 years that two forms of methane monooxygenase, responsible for oxidizing methane to methanol, exist in methanotrophs, i.e., soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO), and that expression of these two forms is controlled by the availability of copper. Specifically, sMMO expression occurs in the absence of copper, while pMMO expression increases with increasing copper concentrations. More recently, it was discovered that multiple forms of methanol dehydrogenase (MeDH), Mxa MeDH and Xox MeDH, also exist in methanotrophs and that the expression of these alternative forms is regulated by the availability of cerium. That is, expression of Xox MeDH increases in the presence of cerium, while Mxa MeDH expression decreases in the presence of cerium. As it had been earlier concluded that pMMO and Mxa MeDH form a supercomplex in which electrons from Mxa MeDH are back donated to pMMO to drive the initial oxidation of methane, we speculated that Mxa MeDH could be rendered inactive through marker-exchange mutagenesis but growth on methane could still be possible if cerium was added to increase the expression of Xox MeDH under sMMO-expressing conditions. Here we report that mxaF, encoding the large subunit of Mxa MeDH, could indeed be knocked out in Methylosinus trichosporium OB3b, yet growth on methane was still possible, so long as cerium was added. Interestingly, growth of this mutant occurred in both the presence and the absence of copper, suggesting that Xox MeDH can replace Mxa MeDH regardless of the form of MMO expressed. PMID:26712545

Dermatitis herpetiformis: a cutaneous manifestation of coeliac disease.

PubMed

Collin, Pekka; Salmi, Teea T; Hervonen, Kaisa; Kaukinen, Katri; Reunala, Timo

2017-02-01

Dermatitis herpetiformis (DH) is an itchy blistering skin disease with predilection sites on elbows, knees, and buttocks. Diagnosis is confirmed by showing granular immunoglobulin A deposits in perilesional skin. DH is one manifestation of coeliac disease; the skin symptoms heal with gluten free diet (GFD) and relapse on gluten challenge. Of the first-degree relatives, 5% may be affected by either condition. Tissue transglutaminase (TG2) is the autoantigen in coeliac disease and epidermal transglutaminase (TG3) in DH. Both diseases conditions exhibit TG2-specific autoantibodies in serum and small bowel mucosa; patients with DH have IgA-TG3 in the skin. There are some divergencies between these two phenotypes. One-fourth of DH patients do not have small bowel mucosal villous atrophy, but virtually all have coeliac-type inflammatory changes. The skin symptoms respond slowly to GFD. The incidence of coeliac disease is increasing, whereas the opposite is true for DH. A female predominance is evident in coeliac disease, while DH may be more common in males. Coeliac disease carries the risk of small intestinal T-cell lymphoma; in DH B-cell lymphomas at any site may prevail. Adult coeliac disease carries a slightly increased elevated mortality risk, whereas in DH, the relative mortality rate is significantly decreased. Key messages Dermatitis herpetiformis is a cutaneous manifestation of coeliac disease; both conditions are genetically determined and gluten-dependent. Gastrointestinal symptoms and the degree of villous atrophy are less obvious in dermatitis herpetiformis than in coeliac disease. Both show tissue transglutaminase (TG2) specific autoantibodies in serum and small bowel mucosa. In addition, TG3-targeted IgA antibodies are found in the skin of DH patients Both conditions carry an increased elevated risk of lymphoma, in coeliac disease small intestinal T-cell lymphoma, in dermatitis herpetiformis mainly B-cell lymphoma at various sites. Coeliac disease is currently eight times more common that DH; the incidence of DH is decreasing in contrast to that of coeliac disease, where it is increasing.

Genetic structure and genealogy in the Sphagnum subsecundum complex (Sphagnaceae: Bryophyta).

PubMed

Shaw, A J; Pokorny, L; Shaw, B; Ricca, M; Boles, S; Szövényi, P

2008-10-01

Allopolyploidy is probably the most extensively studied mode of plant speciation and allopolyploid species appear to be common in the mosses (Bryophyta). The Sphagnum subsecundum complex includes species known to be gametophytically haploid or diploid, and it has been proposed that the diploids (i.e., with tetraploid sporophytes) are allopolyploids. Nucleotide sequence and microsatellite variation among haploids and diploids from Newfoundland and Scandinavia indicate that (1) the diploids exhibit fixed or nearly fixed heterozygosity at the majority of loci sampled, and are clearly allopolyploids, (2) diploids originated independently in North America and Europe, (3) the European diploids appear to have the haploid species, S. subsecundum, as the maternal parent based on shared chloroplast DNA haplotypes, (4) the North American diploids do not have the chloroplast DNA of any sampled haploid, (5) both North American and European diploids share nucleotide and microsatellite similarities with S. subsecundum, (6) the diploids harbor more nucleotide and microsatellite diversity than the haploids, and (7) diploids exhibit higher levels of linkage disequilibrium among microsatellite loci. An experiment demonstrates significant artifactual recombination between interspecific DNAs coamplified by PCR, which may be a complicating factor in the interpretation of sequence-based analyses of allopolyploids.

Potential for the evolution of heavy metal tolerance in Bryum argenteum, a moss. I. Variation within and among populations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, J.; Beer, S.C.; Lutz, J.

Bryum argenteum frequently occurs in urban environments and therefore appears to have the ability to tolerate high levels of such atmospheric pollutants as lead. The presence of genetic variation for tolerance to lead was assessed within and among three populations of this species from Ithaca, New York state. Plants from these populations contained extremely different concentrations of lead and other metals, but there was little or no variation in metal tolerance among the populations. There were, however, significant differences in general vigor (growth rates across all experimental treatments) among populations. Moreover, the rural and suburban populations contained high levels ofmore » variation in vigor among haploid-sib families (families of gametophytes derived from different sporophytes). The urban population, in contrast, contained conspicuously less variation than the other two.« less

Variation among Populations of Belonolaimus longicaudatus.

PubMed

Robbins, R T; Hirschmann, H

1974-04-01

Three North Carolina populations of Belonolairnus longicaudatus differed significantly from three Georgia populations in stylet measurements, the c ratio, the distance of the excretory pore from the anterior end for both sexes; the a ratio for females only; and the total body length, tail length, and spicule length for males only. The Georgia nematodes were stouter, and the females possessed sclerotized vaginal pieces. The distal portion of the spicules of North Carolina males had an indentation and hump lacking in those of the Georgia males. The haploid number of chromosomes was eight for males from all populations of B. longicaudatus and a North Carolina population of B. maritimus. Interpopulation matings of the Tarboro, N.C. and Tifton, Ga. populations indicated that the offspring produced were infertile. Morphological differences and reproductive isolation suggest that the North Carolina and the Georgia populations belong to different species.

Involvement of the dehydroleucodine alpha-methylene-gamma-lactone function in GVBD inhibition in Bufo arenarum oocytes.

PubMed

Sánchez Toranzo, G; López, L A; Martínez, J Zapata; Bühler, M C Gramajo; Bühler, M I

2010-02-01

Dehydroleucodine (DhL), a sesquiterpenic lactone, was isolated and purified from aerial parts of Artemisia douglasiana Besser, a medicinal herb used in Argentina. DhL is an alpha-methylene butyro-gamma-lactone ring connected to a seven-membered ring fused to an exocyclic alpha,beta-unsaturated cyclopentenone ring. It has been previously shown that DhL selectively induces a dose-dependent transient arrest in G2 of both meristematic cells and vascular smooth muscle cells. Treatment with DhL induces an inhibition of spontaneous and progesterone-induced maturation in a dose-dependent manner in Bufo arenarum fully grown oocytes arrested at G2, at the beginning of meiosis I. However, the nature of the mechanisms involved in the process is still unknown. The aim of this work was to analyse whether DhL's alpha-methylene-gamma-lactone function is responsible for the inhibition effect on meiosis reinitiation of Bufo arenarum oocytes as well as some of the transduction pathways that could be involved in this effect using a derivative of DhL inactivated for alpha-methylenelactone, the 11,13-dihydro-dehydroleucodine (2H-DhL). The use of 2H-DhL in the maturation promoting factor (MPF) amplification experiments by injection of both cytoplasm with active MPF and of germinal vesicle content showed results similar to the ones obtained with DhL, suggesting that the hydrogenated derivative would act in a similar way to DhL. Pretreatment with DhL or 2H-DhL did not affect the percentage of germinal vesicle breakdown (GVBD) induced by H89, a protein kinase A (PKA) inhibitor, which suggests that these lactones would act on another step of the signalling pathway that induces MPF activation. The fact that both DhL and 2H-Dhl inhibit GVBD induced by okadaic acid microinjection suggests that they could act on the activity of the Myt1 kinase. This idea is supported by the experiments of injection of GV contents in which an inhibitory effect of these lactones on GVBD was also observed. Our results indicate that the inhibitory effect on meiosis progression of DhL does not depend only on the activity of the alpha-methylenelactone function, as its hydrogenated derivative, 2H-DhL, in which this function has been inactivated, causes similar effects on amphibian oocytes. However, 2H-DhL was less active than DhL as higher doses were required to obtain a significant inhibition. On the other hand, the analysis of the participation of certain mediators in some of the signalling pathways leading to MPF activation suggests that the Myt1 kinase could be a target of these lactones, while cdc25 phosphatase would not be affected. Besides, the PKA inhibition assays indicate that these lactones would act earlier in the signalling pathways.

Evolution in the Cycles of Life.

PubMed

Bowman, John L; Sakakibara, Keiko; Furumizu, Chihiro; Dierschke, Tom

2016-11-23

The life cycles of eukaryotes alternate between haploid and diploid phases, which are initiated by meiosis and gamete fusion, respectively. In both ascomycete and basidiomycete fungi and chlorophyte algae, the haploid-to-diploid transition is regulated by a pair of paralogous homeodomain protein encoding genes. That a common genetic program controls the haploid-to-diploid transition in phylogenetically disparate eukaryotic lineages suggests this may be the ancestral function for homeodomain proteins. Multicellularity has evolved independently in many eukaryotic lineages in either one or both phases of the life cycle. Organisms, such as land plants, exhibiting a life cycle whereby multicellular bodies develop in both the haploid and diploid phases are often referred to as possessing an alternation of generations. We review recent progress on understanding the genetic basis for the land plant alternation of generations and highlight the roles that homeodomain-encoding genes may have played in the evolution of complex multicellularity in this lineage.

Genetic Analysis of Haploids from Industrial Strains of Baker's Yeast

PubMed Central

Oda, Yuji; Ouchi, Kozo

1989-01-01

Strains of baker's yeast conventionally used by the baking industry in Japan were tested for the ability to sporulate and produce viable haploid spores. Three isolates which possessed the properties of baker's yeasts were obtained from single spores. Each strain was a haploid, and one of these strains, YOY34, was characterized. YOY34 fermented maltose and sucrose, but did not utilize galactose, unlike its parental strain. Genetic analysis showed that YOY34 carried two MAL genes, one functional and one cryptic; two SUC genes; and one defective gal gene. The genotype of YOY34 was identified as MATα MAL1 MAL3g SUC2 SUC4 gall. The MAL1 gene from this haploid was constitutively expressed, was dominant over other wild-type MAL tester genes, and gave a weak sucrose fermentation. YOY34 was suitable for both bakery products, like conventional baker's yeasts, and for genetic analysis, like laboratory strains. PMID:16347967

Molecular cloning and expression analysis of the gene encoding proline dehydrogenase from Jatropha curcas L.

PubMed

Wang, Haibo; Ao, Pingxing; Yang, Shuanglong; Zou, Zhurong; Wang, Shasha; Gong, Ming

2015-03-01

Proline dehydrogenase (ProDH) (EC 1.5.99.8) is a key enzyme in the catabolism of proline. The enzyme JcProDH and its complementary DNA (cDNA) were isolated from Jatropha curcas L., an important woody oil plant used as a raw material for biodiesels. It has been classified as a member of the Pro_dh superfamily based on multiple sequence alignment, phylogenetic characterization, and its role in proline catabolism. Its cDNA is 1674 bp in length with a complete open reading frame of 1485 bp, which encodes a polypeptide chain of 494 amino acids with a predicted molecular mass of 54 kD and a pI of 8.27. Phylogenetic analysis indicated that JcProDH showed high similarity with ProDH from other plants. Reverse transcription PCR (RT-PCR) analysis revealed that JcProDH was especially abundant in the seeds and flowers but scarcely present in the stems, roots, and leaves. In addition, the expression of JcProDH increased in leaves experiencing environmental stress such as cold (5 °C), heat (42 °C), salt (300 mM), and drought (30 % PEG6000). The JcProDH protein was successfully expressed in the yeast strain INVSc1 and showed high enzyme activity in proline catabolism. This result confirmed that the JcProDH gene negatively participated in the stress response.

Abnormalities of serum potassium concentration in dialysis-associated hyperglycemia and their correction with insulin: review of published reports.

PubMed

Tzamaloukas, Antonios H; Ing, Todd S; Elisaf, Moses S; Raj, Dominic S C; Siamopoulos, Kostas C; Rohrscheib, Mark; Murata, Glen H

2011-06-01

The main difference between dialysis-associated hyperglycemia (DH) and diabetic ketoacidosis (DKA) or nonketotic hyperglycemia (NKH) occurring in patients with preserved renal function is the absence of osmotic diuresis in DH, which eliminates the need for large fluid and solute (including potassium) replacement. We analyzed published reports of serum potassium (K(+)) abnormalities and their treatment in DH. Hyperkalemia was often present at presentation of DH with higher frequency and severity than in hyperglycemic syndromes in patients with preserved renal function. The frequency and severity of hyperkalemia were higher in DH episodes with DKA than those with NKH in both hemodialysis and peritoneal dialysis. For DKA, the frequency and severity of hyperkalemia were similar in hemodialysis and peritoneal dialysis. For NKH, hyperkalemia was more severe and frequent in hemodialysis than in peritoneal dialysis. Insulin infusion corrected the hyperkalemia of DH in most cases. Additional measures for the management of hyperkalemia or modest potassium infusions for hypokalemia were needed in a few DH episodes. The predictors of the decrease in serum K(+) during treatment of DH with insulin included the starting serum K(+) level, the decreases in serum values of glucose concentration and tonicity, and the increase in serum total carbon dioxide level. DH represents a risk factor for hyperkalemia. Insulin infusion is the only treatment for hyperkalemia usually required.

Specific Location of Disc Hemorrhage is Linked to Nerve Fiber Layer Defects.

PubMed

Yoo, Young Cheol; Kim, Joon Mo; Park, Han Seok; Yoo, Chungkwon; Shim, Seong Hee; Won, Yu Sam; Park, Ki Ho; Chang, Robert T

2017-06-01

To investigate the relationship between retinal nerve fiber layer (RNFL) defects and the quadrant and proximal location of disc hemorrhages (DHs) in a large population examined for health screening. A total of 168,044 subjects older than 20 years underwent a single screening ophthalmic examination with color fundus photography as part of a comprehensive health screening program. The presence and location of DHs and RNFL defects were assessed. The DH locations were defined according to the quadrant location (inferotemporal, superotemporal, inferonasal, or superonasal) and the most proximal end of DHs relative to the disc center (cup base, cup margin, disc rim, or extrapapillary region). Using these two location descriptors as independent variables, a logistic regression analysis was conducted to explore the effects of DH location on RNFL defects. Two hundred twenty-six eyes had DH and 120 (53.1%) of them had RNFL defects. After adjusting for proximal location, DHs located in the inferotemporal quadrant accompanied RFNL defects 12 times more frequently than those in the superonasal quadrant (odds ratio [OR], 11.81; P = .004). Conversely, after adjusting for quadrant location, the ORs for an associated RNFL defect were 3.73 (P < .001), 16.54 (P < .001), and 8.91 (P = .002) for DHs with the proximal end at the disc rim, cup margin, and cup base, respectively. Among the four quadrants and four proximal locations, DHs were identified most frequently in the inferotemporal quadrant and outside the disc, respectively. Some DH locations, such as the inferotemporal quadrant and the cup margin, were associated with RNFL defects, whereas others were not.

Variation of sesquiterpene lactone contents in different Arnica montana populations: influence of ecological parameters.

PubMed

Seemann, Andreas; Wallner, Teresa; Poschlod, Peter; Heilmann, Jörg

2010-05-01

In ten grassland or heathland sites along a geographic (north to south) and climatic gradient in Germany, flowerheads of Arnica montana were collected, and the total content of sesquiterpene lactones (SLs) as well as the content of the detected single compounds were determined. The ratios of helenalin (H)- and corresponding 11 alpha,13-dihydrohelenalin(DH)-type compounds were calculated. All habitats were characterised concerning the climatic and soil conditions, and the values obtained were correlated with SL contents according to univariate statistical analyses. All populations showed very similar and constant ratios of helenalin ( 1)/11 alpha,13-dihydrohelenalin ( 2) at around 1.5-2/1 irrespective of different ecological parameters. The ratio of helenalin/11 alpha,13-dihydrohelenalin esters was several fold higher in all samples, but it was nearly identical in every habitat among each other, except for the helenalin/11 alpha,13-dihydrohelenalin 2-methylbutyrate pair ( 5/ 11), which showed a constantly twofold higher H/DH ratio. However, the 6- O-isovalerylhelenalin content ( 6) showed highly significant correlations to climatic factors. Georg Thieme Verlag KG Stuttgart New York.

[Successful treatment of a patient with two hematologic tumors: double-hit lymphoma and acute myelomonoblastic leukemia].

PubMed

Lukina, A E; Bariakh, E A; Kravchenko, S K; Nareĭko, M V; Kuz'mina, L A; Parovichnikova, E N; Obukhova, T N; Kovrigina, A M; Magomedova, A U

2014-01-01

Double-hit (DH) lymphoma, an extremely aggressive variant of B-cell lymphoma, is accompanied by chromosomal abnormalities leading to the activation of a few oncogenes, one of which is the c-MYC gene in conjunction with BCL2 or BCL6 gene rearrangements. There are most common cases of MYC/8q24 and BCL2/18q21 gene rearrangements (MYC/BCL-2 DH lymphoma). The tumor is characterized by an aggressive clinical course and a poor response to chemotherapy (CT). The median survival in patients with DH lymphomas varies from 4.5 to 18 months. Such patients are generally resistant to CHOP-21 and R-CHOP-21 therapy regimens. For the treatment of patients with DH lymphoma, the Hematology Research Center, Ministry of Health of the Russian Federation, chose an original BL-M-04 polychemotherapy (PCT) protocol in combination with rituximab, followed by autologous stem cell transplantation (allo-SCT). The paper describes the experience in successfully treating a patient with two hematologic tumors: 1) MYC/BCL-2 DH lymphoma with high-dose PCT cycles, followed by allo-SCT, and 2) a metachronously developed second tumor (acute myelomonoblastic leukemia (AMML)) with CT cycles, followed by auto-SCT. The incidence of tumors induced by the previous high-dose CT for aggressive lymphomas for 10 years is 0.7 to 10%. As a rule, the development of secondary AMML is preceded by a history of myelodysplastic syndrome (MDS); characteristic chromosomal abnormalities (deletions of the long arm of chromosomes 5 and 7) are detectable. In this case, the follow-up was 3 months before the development of AMML, during this period the patient was not found to have laboratory signs of MDS (anemia, thrombocytopenia) or chromosomal abnormalities associated with secondary MDS/AML. The presence of a leukemic stem cell is associated with the occurrence and development of hemoblastosis; that of the similar cell populations that may cause B-cell lymphomas remains uncertain. The described case may have defect in a hematopoietic stem cell that gives rise to both germs of hematopoiesis, as well as complete donor chimerism of bone marrow hematopoiesis, which gives hope to long-term remission in both DH lymphoma and AMML.

A survey of dental hygienists in the United Kingdom in 2011. Part 1--demographics and working patterns as dental hygienists.

PubMed

Eaton, K A; Harris, M; Ross, M K; Arevalo, C

2012-11-01

The aims of this survey were to establish the demographic profile of dental hygienists (DHs) and dental hygienist/therapists (DH/Ts) in the United Kingdom in 2011 and their patterns of practice as DHs. A 10% sample of all those registered with the General Dental Council as DHs or DH/Ts in April 2011 were sent a pre-piloted questionnaire, explanatory letter and stamped addressed envelope. The questionnaire contained a total of 100 questions, 24 of which related to demographics and working patterns. All 100 questions were solely on tasks/work performed by DH, none related to other types of work performed by DH/Ts. Three mailings were distributed between May and July 2011. The resulting data were entered into an Excel spreadsheet. Where appropriate, differences between the responses from DHs and DH/Ts were statistically tested with the chi-squared test. Five hundred and sixty-one DHs and DH/Ts were sent the questionnaire, by the third mailing 371 (66.1%) had responded and returned completed questionnaires. The respondents were 288 DHs, 79 DH/Ts and 4 who did not specify which category they were. The mean year of qualification of the DHs was 1990 and for the DH/Ts 2005. One hundred and twenty-four (33%) reported that they worked full-time, 235 (63%) part-time and the remainder that they were not working as DHs or DH/Ts or had retired. The average number of clinical hours worked per week was reported as 24.6 hours for DHs and 25 hours for DH/Ts, but there were regional variations. For DHs the mean percentage of patients treated under NHS contract was 15.5% and for DH/Ts it was 40.2%. Again there were regional variations and in Scotland these figures were 45.5% for DHs and 70% for DH/Ts. Two hundred and forty-eight (69%) of all respondents were either fully or partly self-employed and 221 (62.7%) worked in two or more locations. The results of this study provide a snapshot of the demographics and practice patterns of DHs and DH/Ts in the UK in the summer of 2011. They confirm the results of a survey that was conducted in England in early 2011 and of a survey that took place in Scotland in 2009.

A comprehensively molecular haplotype-resolved genome of a European individual

PubMed Central

Suk, Eun-Kyung; McEwen, Gayle K.; Duitama, Jorge; Nowick, Katja; Schulz, Sabrina; Palczewski, Stefanie; Schreiber, Stefan; Holloway, Dustin T.; McLaughlin, Stephen; Peckham, Heather; Lee, Clarence; Huebsch, Thomas; Hoehe, Margret R.

2011-01-01

Independent determination of both haplotype sequences of an individual genome is essential to relate genetic variation to genome function, phenotype, and disease. To address the importance of phase, we have generated the most complete haplotype-resolved genome to date, “Max Planck One” (MP1), by fosmid pool-based next generation sequencing. Virtually all SNPs (>99%) and 80,000 indels were phased into haploid sequences of up to 6.3 Mb (N50 ∼1 Mb). The completeness of phasing allowed determination of the concrete molecular haplotype pairs for the vast majority of genes (81%) including potential regulatory sequences, of which >90% were found to be constituted by two different molecular forms. A subset of 159 genes with potentially severe mutations in either cis or trans configurations exemplified in particular the role of phase for gene function, disease, and clinical interpretation of personal genomes (e.g., BRCA1). Extended genomic regions harboring manifold combinations of physically and/or functionally related genes and regulatory elements were resolved into their underlying “haploid landscapes,” which may define the functional genome. Moreover, the majority of genes and functional sequences were found to contain individual or rare SNPs, which cannot be phased from population data alone, emphasizing the importance of molecular phasing for characterizing a genome in its molecular individuality. Our work provides the foundation to understand that the distinction of molecular haplotypes is essential to resolve the (inherently individual) biology of genes, genomes, and disease, establishing a reference point for “phase-sensitive” personal genomics. MP1's annotated haploid genomes are available as a public resource. PMID:21813624

Karyological evidence of hybridogenesis in Greenlings (Teleostei: Hexagrammidae).

PubMed

Suzuki, Shota; Arai, Katsutoshi; Munehara, Hiroyuki

2017-01-01

Two types of natural hybrids were discovered in populations of three Hexagrammos species (Teleostei: Hexagrammidae) distributed off the southern coast of Hokkaido in the North Pacific Ocean. Both hybrids reproduce by hybridogenesis, in which the maternal haploid genome is transmitted to offspring without recombination and the paternal haploid genome is eliminated during gametogenesis. While natural hybrids are unisexual and reproduce hemiclonally by backcrossing with the paternal species (BC-P), artificial F1-hybrids between the pure species produce recombinant gametes. Thus, despite having the same genome composition, the natural hybrids and the F1-hybrids are not genetically identical. Here, to clarify the differences between both hybrids, we examined the karyotypes of the three Hexagrammos species, their natural hybrids, the artificial F1-hybrids, and several backcrosses. Artificial F1-hybrids have karyotypes and chromosome numbers that are intermediate between those of the parental species. Conversely, the natural hybrids differed from F1-hybrids by having several large metacentric chromosomes and microchromosomes. Since the entire maternal haploid genome is inherited by the natural hybrids, maternal backcrosses (BC-M) between natural hybrids and males of the maternal species (H. octogrammus; Hoc) have a hemiclonal Hoc genome with large chromosomes from the mother and a normal Hoc genome from the father. However, the large chromosomes disappear in offspring of BC-M, probably due to fissuring during gametogenesis. Similarly, microsatellite DNA analysis revealed that chromosomes of BC-M undergo recombination. These findings suggest that genetic factors associated with hemiclonal reproduction may be located on the large metacentric chromosomes of natural hybrids.

Ninety-six haploid yeast strains with individual disruptions of open reading frames between YOR097C and YOR192C, constructed for the Saccharomyces genome deletion project, have an additional mutation in the mismatch repair gene MSH3.

PubMed

Lehner, Kevin R; Stone, Megan M; Farber, Rosann A; Petes, Thomas D

2007-11-01

As part of the Saccharomyces Genome Deletion Project, sets of presumably isogenic haploid and diploid strains that differed only by single gene deletions were constructed. We found that one set of 96 strains (containing deletions of ORFs located between YOR097C and YOR192C) in the collection, which was derived from the haploid BY4741, has an additional mutation in the MSH3 mismatch repair gene.

Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae) - A comparison with haploid males, queens and workers.

PubMed

Borges, Andreia A; Humann, Fernanda C; Oliveira Campos, Lucio A; Tavares, Mara G; Hartfelder, Klaus

2011-10-01

In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males.

Artificial induction of mito-gynogenetic diploids in large yellow croaker ( Pseudosciaena crocea) by hydrostatic pressure

NASA Astrophysics Data System (ADS)

Cai, Mingyi; Wu, Qingming; Liu, Xiande; Yao, Cuiluan; Chen, Qingkai; Wang, Zhiyong

2010-07-01

The present study investigated conditions for inducing mito-gynogenetic (endomitosis) diploids by hydrostatic pressure in the large yellow croaker Pseudosciaena crocea. In haploid control groups, the development of eggs was activated with ultraviolet radiated semen. All fry presented typical haploid syndrome in the haploid control groups, and were verified as haploids using cytometry. After hydrostatic pressure treatment, morphologically normal fry reappeared at different frequencies according to the intensity and time of pressure shock. Fry with normal appearance in the pressure treated groups were verified as gynogenetic double haploids (GDHs), containing only one allele from the female parent at all four diagnostic microsatellite loci. For a fixed duration of 3 min, the optimal intensity of blocking the first mitosis was determined to be 40 Mpa, which was similar to that of blocking the second meiosis. There was a “window” of starting time, from 36.1 min to 38.1 min post-insemination at 25.0±1.0°C, within which the production of GDHs was not significantly different. Maximum production of morphologically normal fries, 9.36%±2.97% of developed eggs, was found when the eggs were shocked with hydrostatic pressure at 40 Mpa for 3 min, starting from 38.1 min post insemination at 25.0±1.0°C.

Comparing dynamic hyperinflation and associated dyspnea induced by metronome-paced tachypnea versus incremental exercise.

PubMed

Calligaro, Gregory L; Raine, Richard I; Bateman, Mary E; Bateman, Eric D; Cooper, Christopher B

2014-02-01

Dynamic hyperinflation (DH) during exercise is associated with both dyspnea and exercise limitation in COPD. Metronome-paced tachypnoea (MPT) is a simple alternative for studying DH. We compared MPT with exercise testing (XT) as methods of provoking DH, and assessed their relationship with dyspnea. We studied 24 patients with moderate COPD (FEV1 59 ± 9% predicted) after inhalation of ipratropium/salbutamol combination or placebo in a double-blind, crossover design. Inspiratory capacity (IC) was measured at baseline and after 30 seconds of MPT with breathing frequencies (fR) of 20, 30 and 40 breaths/min and metronome-defined I:E ratios of 1:1 and 1:2, in random sequence, followed by incremental cycle ergometry with interval determinations of IC. DH was defined as a decline in IC from baseline (∆IC) for both methods. Dyspnea was assessed using a Borg CR-10 scale. ∆IC during MPT was greater with higher fR and I:E ratio of 1:1 versus 1:2, and less when patients were treated with bronchodilator rather than placebo (P = 0.032). DH occurred during 19 (40%) XTs, and during 35 (73%) tests using MPT. Eleven of 18 (61%) non-congruent XTs (where DH occurred on MPT but not XT) terminated before fR of 40 breaths/min was reached. Although greater during XT, the intensity of dyspnea bore no relationship to DH during either MPT and XT. MPT at 40 breaths/min and I:E of 1:1 elicits the greatest ∆IC, and is a more sensitive method for demonstrating DH. The relationship between DH and dyspnea is complex and not determined by DH alone.

Chemical activation in Rhinella arenarum oocytes: effect of dehydroleucodine (DhL) and its hydrogenated derivative (2H-DhL).

PubMed

Medina, M F; Bühler, M I; Sánchez-Toranzo, G

2015-12-01

Mature oocytes are arrested in metaphase II due to the presence of high levels of active maturation promoting factor (MPF). After fertilization, active MPF levels decline abruptly, enabling oocytes to complete meiosis II. One of the first and universal events of oocyte activation is an increase in cytosolic Ca2+ that would be responsible for MPF inactivation. Mature oocytes can also be activated by parthenogenetic activation. The aims of this work are to test the ability of dehydroleucodine (DhL) and its hydrogenated derivative 11,13-dihydro-dehydroleucodine (2H-DhL) to induce chemical activation in amphibian oocytes and to study the participation of calcium in the process. Results indicated that DhL and 2H-DhL induced oocyte activation in a dose-dependent manner. After 90 min of treatment, DhL 36 μM was able to induce 95% activation, while 2H-DhL 36 μM was less active, with only 40% activation. Our results suggest that DhL induced the inhibition of MPF activity, probably by an increase in intracellular Ca2+ concentration. Extracellular Ca2+ would not be significant, although Ca2+ release from intracellular stores is critical. In this sense, IP3Rs and RyRs were involved in the Ca2+ transient induced by lactones. In this species, RyRs appears to be the largest contributor to Ca2+ release in DhL-induced activation. Although more studies are needed on the mechanism of action through which these lactones induce oocyte activation in Rhinella arenarum, the results of this research provide interesting perspectives for the use of these lactones as chemical activators in in vitro fertilization and cloning.

Measurement of dentin hypersensitivity with the Jay Sensitivity Sensor Probe and the Yeaple probe to compare relief from dentin hypersensitivity by dentifrices.

PubMed

Kakar, Ashish; Kakar, Kanupriya

2013-05-01

To compare relief from dentin hypersensitivity (DH) after use of dentifrices formulated with potassium nitrate or fluoride. For the study, DH evaluations were conducted with the Jay Sensitivity Sensor Probe (Jay Probe), a novel tactile hypersensitivity instrument, in conjunction with three other DH methods, i.e. Yeaple probe (tactile), air blast, and the Visual Analog Scale (VAS). Adults (n = 100) who presented two teeth with DH and met study criteria were enrolled for this double-blind, randomized, parallel, controlled clinical trial conducted in an outpatient setting. DH evaluations at baseline were conducted by the tactile, air blast, and VAS methods. Subjects were randomly assigned a dentifrice formulated with 5% potassium nitrate and 1,000 ppm fluoride (as sodium monofluorophosphate) (Colgate Sensitive toothpaste; Test) or a commercially available fluoride dentifrice with 1,000 ppm fluoride as sodium monofluorophosphate (Colgate Cibaca toothpaste; Negative control). Subjects were recalled for DH evaluations after 4 and 8 weeks of product use. 85 subjects completed the entire study with evaluable results. Both treatments resulted in significant reductions in DH from baseline to all recall visits. In comparison to the Negative control, subjects in the Test group demonstrated significantly greater reductions for all DH evaluations at both 4 and 8 weeks (P < 0.05). Average tactile DH scores at week 8 for the Test and Negative control groups were 36.25 and 15.24 with the Yeaple probe and 35 and 12.43 with the Jay probe. Correspondingly, subjects in the Test group demonstrated significantly greater reductions in air blast and VAS responses for DH than those in the Negative control group (P < 0.05).

Dehydroleucodine inhibits tumor growth in a preclinical melanoma model by inducing cell cycle arrest, senescence and apoptosis.

PubMed

Costantino, Valeria V; Lobos-Gonzalez, Lorena; Ibañez, Jorge; Fernandez, Dario; Cuello-Carrión, F Darío; Valenzuela, Manuel A; Barbieri, Manuel A; Semino, Silvana N; Jahn, Graciela A; Quest, Andrew F G; Lopez, Luis A

2016-03-01

Malignant melanoma represents the fastest growing public health risk of all cancer types worldwide. Several strategies and anti-cancer drugs have been used in an effort to improve treatments, but the development of resistance to anti-neoplastic drugs remains the major cause of chemotherapy failure in melanomas. Previously, we showed that the sesquiterpene lactone, dehydroleucodine (DhL), promotes the accumulation of DNA damage markers, such as H2AX and 53BP1, in human tumor cells. Also DhL was shown to trigger either cell senescence or apoptosis in a concentration-dependent manner in HeLa and MCF7 cells. Here, we evaluated the effects of DhL on B16F0 mouse melanoma cells in vitro and in a pre-clinical melanoma model. DhL inhibited the proliferation of B16F0 cells by inducing senescence or apoptosis in a concentration-dependent manner. Also, DhL reduced the expression of the cell cycle proteins cyclin D1 and B1 and the inhibitor of apoptosis protein, survivin. In melanomas generated by subcutaneous injection of B16F0 cells into C57/BL6 mice, the treatment with 20 mg DhL /Kg/day in preventive, simultaneous and therapeutic protocols reduced tumor volumes by 70%, 60% and 50%, respectively. DhL treatments reduced the number of proliferating, while increasing the number of senescent and apoptotic tumor cells. To estimate the long-term effects of DhL, a mathematical model was applied to fit experimental data. Extrapolation beyond experimental time points revealed that DhL administration following preventive and therapeutic protocols is predicted to be more effective than simultaneous treatments with DhL in restricting tumor growth. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Stage-dependent and temperature-controlled expression of the gene encoding the precursor protein of diapause hormone and pheromone biosynthesis activating neuropeptide in the silkworm, Bombyx mori.

PubMed

Xu, W H; Sato, Y; Ikeda, M; Yamashita, O

1995-02-24

Embryonic diapause and sex pheromone biosynthesis in the silkworm, Bombyx mori, are, respectively, induced by diapause hormone (DH) and pheromone biosynthesis activating neuropeptide (PBAN), which are produced in the subesophageal ganglion from a common polyprotein precursor (DH-PBAN precursor) encoded by a single gene (DH-PBAN gene). Using DH-PBAN cDNA as a probe, we quantitatively measured DH-PBAN mRNA content throughout embryonic and postembryonic development and observed the effects of incubation temperature, which is a key factor for determination of diapause, on DH-PBAN gene expression. The silkworm, which is programmed to lay diapause eggs by being incubated at 25 degrees C, showed peaks of DH-PBAN mRNA content at five different stages throughout the life cycle: at the late embryonic stage, at the middle of the fourth and the fifth larval instars, and at early and late stages of pupal-adult development. In the non-diapause type silkworms programmed by a 15 degrees C incubation, only the last peak of DH-PBAN mRNA in pupal-adult development was found, and the other peaks were absent. Furthermore, interruption of the incubation period at 25 degrees C by incubation at 15 degrees C decreased both DH-PBAN mRNA content in mature embryos and in subesophageal ganglia of day 3 pupae and the incidence of diapause eggs. Thus, there were two types of regulatory mechanisms for DH-PBAN gene expression. One is a temperature-controlled expression that is responsible for diapause induction, and the other is a temperature-independent, stage-dependent expression related to pheromone production.

A behavior-oriented dynamic model for sandbar migration and 2DH evolution

USGS Publications Warehouse

Splinter, K.D.; Holman, R.A.; Plant, N.G.

2011-01-01

A nonlinear model is developed to study the time-dependent relationship between the alongshore variability of a sandbar, a(t), and alongshore-averaged sandbar position, xc(t). Sediment transport equations are derived from energetics-based formulations. A link between this continuous physical representation and a parametric form describing the migration of sandbars of constant shape is established through a simple transformation of variables. The model is driven by offshore wave conditions. The parametric equations are dynamically coupled such that changes in one term (i.e., xc) drive changes in the other (i.e., a(t)). The model is tested on 566 days of data from Palm Beach, New South Wales, Australia. Using weighted nonlinear least squares to estimate best fit model coefficients, the model explained 49% and 41% of the variance in measured xc and a(t), respectively. Comparisons against a 1-D horizontal (1DH) version of the model showed significant improvements when the 2DH terms were included (1DH and 2DH Brier skill scores were -0.12 and 0.42, respectively). Onshore bar migration was not predicted in the 1DH model, while the 2DH model correctly predicted onshore migration in the presence of 2DH morphology and allowed the bar to remain closer to shore for a given amount of breaking, providing an important hysteresis to the system. The model is consistent with observations that active bar migration occurs under breaking waves with onshore migration occurring at timescales of days to weeks and increasing 2DH morphology, while offshore migration occurs rapidly under high waves and coincides with a reduction in 2DH morphology. Copyright ?? 2011 by the American Geophysical Union.

Interstellar organic matter in meteorites

NASA Technical Reports Server (NTRS)

Yang, J.; Epstein, S.

1983-01-01

Deuterium-enriched hydrogen is present in organic matter in such meteorites as noncarbonaceous chondrites. The majority of the unequilibrated primitive meteorites contain hydrogen whose D/H ratios are greater than 0.0003, requiring enrichment (relative to cosmic hydrogen) by isotope exchange reactions taking place below 150 K. The D/H values presented are the lower limits for the organic compounds derived from interstellar molecules, since all processes subsequent to their formation, including terrestrial contamination, decrease their D/H ratios. In contrast, the D/H ratios of hydrogen associated with hydrated silicates are relatively uniform for the meteorites analyzed. The C-13/C-12 ratios of organic matter, irrespective of D/H ratio, lie well within those observed for the earth. Present findings suggest that other interstellar material, in addition to organic matter, is preserved and is present in high D/H ratio meteorites.

New measurements of D/H on Mars using EXES aboard SOFIA

NASA Astrophysics Data System (ADS)

Encrenaz, T.; DeWitt, C.; Richter, M. J.; Greathouse, T. K.; Fouchet, T.; Montmessin, F.; Lefèvre, F.; Bézard, B.; Atreya, S. K.; Aoki, S.; Sagawa, H.

2018-05-01

The global D/H ratio on Mars is an important measurement for understanding the past history of water on Mars; locally, through condensation and sublimation processes, it is a possible tracer of the sources and sinks of water vapor on Mars. Measuring D/H as a function of longitude, latitude and season is necessary for determining the present averaged value of D/H on Mars. Following an earlier measurement in April 2014, we used the Echelon Cross Echelle Spectrograph (EXES) instrument on board the Stratospheric Observatory for Infrared Astronomy (SOFIA) facility to map D/H on Mars on two occasions, on March 24, 2016 (Ls = 127°), and January 24, 2017 (Ls = 304°), by measuring simultaneously the abundances of H2O and HDO in the 1383-1391 cm-1 range (7.2 μm). The D/H disk-integrated values are 4.0 (+0.8, -0.6) × Vienna Standard Mean Ocean Water (VSMOW) and 4.5 (+0.7, -0.6) × VSMOW, respectively, in agreement with our earlier result. The main result of this study is that there is no evidence of strong local variations in the D/H ratio nor for seasonal variations in the global D/H ratio between northern summer and southern summer.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xin, Qiaoling, E-mail: xinqiaoling0923@163.com; Jiang, Lining, E-mail: jianglining@bit.edu.cn

Let G be a finite group and H a normal subgroup. D(H; G) is the crossed product of C(H) and CG which is only a subalgebra of D(G), the double algebra of G. One can construct a C*-subalgebra F{sub H} of the field algebra F of G-spin models, so that F{sub H} is a D(H; G)-module algebra, whereas F is not. Then the observable algebra A{sub (H,G)} is obtained as the D(H; G)-invariant subalgebra of F{sub H}, and there exists a unique C*-representation of D(H; G) such that D(H; G) and A{sub (H,G)} are commutants with each other.

Genetic Diversity in the UV Sex Chromosomes of the Brown Alga Ectocarpus.

PubMed

Avia, Komlan; Lipinska, Agnieszka P; Mignerot, Laure; Montecinos, Alejandro E; Jamy, Mahwash; Ahmed, Sophia; Valero, Myriam; Peters, Akira F; Cock, J Mark; Roze, Denis; Coelho, Susana M

2018-06-06

Three types of sex chromosome system exist in nature: diploid XY and ZW systems and haploid UV systems. For many years, research has focused exclusively on XY and ZW systems, leaving UV chromosomes and haploid sex determination largely neglected. Here, we perform a detailed analysis of DNA sequence neutral diversity levels across the U and V sex chromosomes of the model brown alga Ectocarpus using a large population dataset. We show that the U and V non-recombining regions of the sex chromosomes (SDR) exhibit about half as much neutral diversity as the autosomes. This difference is consistent with the reduced effective population size of these regions compared with the rest of the genome, suggesting that the influence of additional factors such as background selection or selective sweeps is minimal. The pseudoautosomal region (PAR) of this UV system, in contrast, exhibited surprisingly high neutral diversity and there were several indications that genes in this region may be under balancing selection. The PAR of Ectocarpus is known to exhibit unusual genomic features and our results lay the foundation for further work aimed at understanding whether, and to what extent, these structural features underlie the high level of genetic diversity. Overall, this study fills a gap between available information on genetic diversity in XY/ZW systems and UV systems and significantly contributes to advancing our knowledge of the evolution of UV sex chromosomes.

Determinants of dynamic hyperinflation during metronome-paced tachypnea in COPD and normal subjects.

PubMed

Cooper, C B; Calligaro, G L; Quinn, M M; Eshaghian, P; Coskun, F; Abrazado, M; Bateman, E D; Raine, R I

2014-01-01

In COPD, dynamic hyperinflation (DH) occurs during exercise and during metronome-paced tachypnea (MPT). We investigated the relationship of DH with breathing pattern and ventilation (V˙E) in COPD and normal subjects (NS). In 35 subjects with moderate COPD and 17 younger healthy volunteers we measured inspiratory capacity (IC), breathing frequency (fR), expiratory time (TE), ventilation (V˙E) and end-tidal carbon dioxide tension (PETCO2) at baseline and after 30s of MPT at 40breaths/min with metronome-defined I:E ratios of 1:1 and 1:2. A reduction in IC (ΔIC) was taken to indicate DH. In COPD subjects, DH correlated with TE but not with V˙E or PETCO2, and was best predicted by total lung capacity. NS also showed DH (although less than in COPD), which correlated with PETCO2 but not with fR, TE or V˙E. We conclude that MPT evokes DH in both NS and patients with COPD. TE is the most important determinant of DH during MPT in patients with COPD. Copyright © 2013 Elsevier B.V. All rights reserved.

The arbuscular mycorrhizal fungus Glomus intraradices is haploid and has a small genome size in the lower limit of eukaryotes.

PubMed

Hijri, Mohamed; Sanders, Ian R

2004-02-01

The genome size, complexity, and ploidy of the arbuscular mycorrhizal fungus (AMF) Glomus intraradices was determined using flow cytometry, reassociation kinetics, and genomic reconstruction. Nuclei of G. intraradices from in vitro culture, were analyzed by flow cytometry. The estimated average length of DNA per nucleus was 14.07+/-3.52 Mb. Reassociation kinetics on G. intraradices DNA indicated a haploid genome size of approximately 16.54 Mb, comprising 88.36% single copy DNA, 1.59% repetitive DNA, and 10.05% fold-back DNA. To determine ploidy, the DNA content per nucleus measured by flow cytometry was compared with the genome estimate of reassociation kinetics. G. intraradices was found to have a DNA index (DNA per nucleus per haploid genome size) of approximately 0.9, indicating that it is haploid. Genomic DNA of G. intraradices was also analyzed by genomic reconstruction using four genes (Malate synthase, RecA, Rad32, and Hsp88). Because we used flow cytometry and reassociation kinetics to reveal the genome size of G. intraradices and show that it is haploid, then a similar value for genome size should be found when using genomic reconstruction as long as the genes studied are single copy. The average genome size estimate was 15.74+/-1.69 Mb indicating that these four genes are single copy per haploid genome and per nucleus of G. intraradices. Our results show that the genome size of G. intraradices is much smaller than estimates of other AMF and that the unusually high within-spore genetic variation that is seen in this fungus cannot be due to high ploidy.

Adapting rice anther culture to gene transformation and RNA interference.

PubMed

Chen, Caiyan; Xiao, Han; Zhang, Wenli; Wang, Aiju; Xia, Zhihui; Li, Xiaobing; Zhai, Wenxue; Cheng, Zhukuan; Zhu, Lihuang

2006-10-01

Anther culture offers a rapid method of generating homozygous lines for breeding program and genetic analysis. To produce homozygous transgenic lines of rice (Oryza sativa L.) in one step, we developed an efficient protocol of anther-callus-based transformation mediated by Agrobacterium after optimizing several factors influencing efficient transformation, including callus induction and Agrobacterium density for co-cultivation. Using this protocol, we obtained 145 independent green transformants from five cultivars of japonica rice by transformation with a binary vector pCXK1301 bearing the rice gene, Xa21 for resistance to bacterial blight, of which 140 were further confirmed by PCR and Southern hybridization analysis, including haploids (32.1%), diploids (62.1%) and mixoploids (7.5%). Fifteen diploids were found to be doubled haploids, which accounted for 10.7% of the total positive lines. Finally, by including 28 from colchicine induced or spontaneous diploidization of haploids later after transformation, a total of 43 doubled haploids (30.7%) of Xa21 transgenic lines were obtained. We also generated two RNAi transgenic haploids of the rice OsMADS2 gene, a putative redundant gene of OsMADS4 based on their sequence similarity, to investigate its possible roles in rice flower development by this method. Flowers from the two OsMADS2 RNAi transgenic haploids displayed obvious homeotic alternations, in which lodicules were transformed into palea/lemma-like tissues, whereas identities of other floral organs were maintained. The phenotypic alternations were proved to result from specific transcriptional suppression of OsMADS2 gene by the introduced RNAi transgene. The results confirmed that OsMADS2 is involved in lodicule development of rice flower and functionally redundant with OsMADS4 gene. Our results demonstrated that rice anther culture could be adapted to gene transformation and RNAi analysis in rice.

A Genome-Wide Association Study Identifies Genomic Regions for Virulence in the Non-Model Organism Heterobasidion annosum s.s

PubMed Central

Dalman, Kerstin; Himmelstrand, Kajsa; Olson, Åke; Lind, Mårten; Brandström-Durling, Mikael; Stenlid, Jan

2013-01-01

The dense single nucleotide polymorphisms (SNP) panels needed for genome wide association (GWA) studies have hitherto been expensive to establish and use on non-model organisms. To overcome this, we used a next generation sequencing approach to both establish SNPs and to determine genotypes. We conducted a GWA study on a fungal species, analysing the virulence of Heterobasidion annosum s.s., a necrotrophic pathogen, on its hosts Picea abies and Pinus sylvestris. From a set of 33,018 single nucleotide polymorphisms (SNP) in 23 haploid isolates, twelve SNP markers distributed on seven contigs were associated with virulence (P<0.0001). Four of the contigs harbour known virulence genes from other fungal pathogens and the remaining three harbour novel candidate genes. Two contigs link closely to virulence regions recognized previously by QTL mapping in the congeneric hybrid H. irregulare × H. occidentale. Our study demonstrates the efficiency of GWA studies for dissecting important complex traits of small populations of non-model haploid organisms with small genomes. PMID:23341945

Augmenting Predictive Modeling Tools with Clinical Insights for Care Coordination Program Design and Implementation.

PubMed

Johnson, Tracy L; Brewer, Daniel; Estacio, Raymond; Vlasimsky, Tara; Durfee, Michael J; Thompson, Kathy R; Everhart, Rachel M; Rinehart, Deborath J; Batal, Holly

2015-01-01

The Center for Medicare and Medicaid Innovation (CMMI) awarded Denver Health's (DH) integrated, safety net health care system $19.8 million to implement a "population health" approach into the delivery of primary care. This major practice transformation builds on the Patient Centered Medical Home (PCMH) and Wagner's Chronic Care Model (CCM) to achieve the "Triple Aim": improved health for populations, care to individuals, and lower per capita costs. This paper presents a case study of how DH integrated published predictive models and front-line clinical judgment to implement a clinically actionable, risk stratification of patients. This population segmentation approach was used to deploy enhanced care team staff resources and to tailor care-management services to patient need, especially for patients at high risk of avoidable hospitalization. Developing, implementing, and gaining clinical acceptance of the Health Information Technology (HIT) solution for patient risk stratification was a major grant objective. In addition to describing the Information Technology (IT) solution itself, we focus on the leadership and organizational processes that facilitated its multidisciplinary development and ongoing iterative refinement, including the following: team composition, target population definition, algorithm rule development, performance assessment, and clinical-workflow optimization. We provide examples of how dynamic business intelligence tools facilitated clinical accessibility for program design decisions by enabling real-time data views from a population perspective down to patient-specific variables. We conclude that population segmentation approaches that integrate clinical perspectives with predictive modeling results can better identify high opportunity patients amenable to medical home-based, enhanced care team interventions.

Evaluation of safety of lipomer doxycycline hydrochloride (lipomer DH).

PubMed

Dhumal, Rohit; Soni, Mahesh; Devarajan, Padma; Samad, Abdul; Gaikwad, Rajiv; Vanage, Geeta

2011-02-01

The nanoparticulate formulation of lipomer doxycycline hydrochloride (lipomer DH) has been synthesized for the treatment of Brucellosis to increase efficacy of the drug. The present study was undertaken to determine the intravenous safety of blank lipomer and Lipomer DH in terms of maximum tolerated dose in rats. It was observed that blank lipomer and lipomer DH were safe when administered intravenously at doses 2000 mg/kg Bw and 18 mg/kg bw respectively.

Complete Genome Sequence of NEB 5-alpha, a Derivative of Escherichia coli K-12 DH5α.

PubMed

Anton, Brian P; Raleigh, Elisabeth A

2016-11-10

Escherichia coli K-12 DH5α is one of the most popular and widely available laboratory strains, but, surprisingly, no complete genome sequence has been publicly available. Here, we report the complete, finished sequence of NEB 5-alpha (DH5α fhuA2). It should serve as a useful reference for researchers working with DH5α. Copyright © 2016 Anton and Raleigh.

Cytological evidence for chromosome elimination in wheat x Imperata cylindrica hybrids.

PubMed

Komeda, Norio; Chaudhary, Harinder K; Suzuki, Go; Mukai, Yasuhiko

2007-06-01

Haploid induction of wheat by crossing with Imperata cylindrica pollen is an efficient method for doubled haploid breeding. We investigated the process of wheat haploid formation after crossing with I. cylindrica. Our cytological observations of zygotes showed the successful fertilization of parental gametes. Wheat haploids were formed by complete elimination of I. cylindrica chromosomes. Missegregation of I. cylindrica chromosomes was observed in the first cell division of zygote. At metaphase I. cylindrica chromosomes did not congress onto the equatorial plate. The sister chromosomes did not move toward the poles during anaphase, though their cohesion was released normally. I. cylindrica chromosomes were still in the cytoplasm at telophase and eliminated from daughter nuclei. After two-celled stage, we could find no I. cylindrica chromosome in the nuclei but micronuclei containing I. cylindrica chromatin in the cytoplasm. These observations indicate that I. cylindrica chromosomes are completely eliminated from nuclei in the first cell division probably due to lack of functional kinetochores.

The discrete hungry Lotka Volterra system and a new algorithm for computing matrix eigenvalues

NASA Astrophysics Data System (ADS)

Fukuda, Akiko; Ishiwata, Emiko; Iwasaki, Masashi; Nakamura, Yoshimasa

2009-01-01

The discrete hungry Lotka-Volterra (dhLV) system is a generalization of the discrete Lotka-Volterra (dLV) system which stands for a prey-predator model in mathematical biology. In this paper, we show that (1) some invariants exist which are expressed by dhLV variables and are independent from the discrete time and (2) a dhLV variable converges to some positive constant or zero as the discrete time becomes sufficiently large. Some characteristic polynomial is then factorized with the help of the dhLV system. The asymptotic behaviour of the dhLV system enables us to design an algorithm for computing complex eigenvalues of a certain band matrix.

Declining trend in the incidence of biopsy-verified coeliac disease in the adult population of Finland, 2005-2014.

PubMed

Virta, L J; Saarinen, M M; Kolho, K-L

2017-12-01

The frequency of coeliac disease (CD) has been on the rise over the past decades, especially in Western Europe, but current trends are unclear. To research the recent temporal changes in the incidence of adult, biopsy-verified coeliac disease and dermatitis herpetiformis (DH) in Finland, a country with a high frequency of coeliac disease. All coeliac disease and DH cases diagnosed at age 20-79 years during 2005-2014 were retrieved from a nationwide database documenting all applicants for monthly compensation to cover the extra cost of maintaining a gluten-free diet. This benefit is granted on the basis of histology, not socioeconomic status. Temporal trends in the annual incidences were estimated using Poisson regression analyses. The total incidence of coeliac disease decreased from 33/100 000 during the years 2005-2006 to 29/100 000 during 2013-2014. The mean annual incidence of coeliac disease was nearly twice as high among women as among men, 42 vs 22 per 100 000, respectively. For middle- and old-aged women, the average rate of decrease in incidence was 4.8% (95% CI 3.9-5.7) per year and for men 3.0% (1.8-4.1) (P for linear trend <.001, for both). Similarly, the annual incidence of DH declined. For young adults, the rate of change remained low and nonsignificant throughout the period 2005-2014. Although the awareness of coeliac disease has increased during the past decades, the incidence of biopsy-verified diagnoses is not increasing, which suggests that exposure to yet unidentified triggering factors for coeliac disease has plateaued among the Finnish adult population. © 2017 John Wiley & Sons Ltd.

Interaction with macrophages attenuates equine fibroblast-like synoviocyte ADAMTS5 (aggrecanase-2) gene expression following inflammatory stimulation.

PubMed

Morgan, Rhiannon E; Clegg, Peter D; Hunt, John A; Innes, John F; Tew, Simon R

2018-03-09

The joint synovium consists of a heterogeneous cell population, chiefly comprised of macrophages, and fibroblast-like synoviocytes (FLS). An inter-species co-culture model was developed to examine interactions between these cells. Equine FLS and the canine macrophage line DH82 were differentially labeled using fluorescent markers and results from direct co-culture compared with those from both indirect co-culture, and conditioned media experiments. The transcript expression of IL-1β, IL-6, ADAMTS4, and ADAMTS5 in each cell type were determined using species-specific qPCR assays. Lipopolysaccharide stimulation of EFLS rapidly increased IL-1β, IL-6, ADAMTS4, and ADAMTS5 mRNAs. The induction of ADAMTS5 was significantly reduced when equine FLS were cultured with DH82 cells directly or indirectly. Exposure of equine FLS to denatured conditioned media also significantly reduced ADAMTS5 induction. DH82 cells increased interleukin-1β expression substantially following LPS stimulation. However, knockdown of interleukin-1β in DH82 cells, or inhibition of NF-κB in equine FLS prior to co-culture did not change the inhibitory effect on equine FLS ADAMTS5 gene expression. This work indicates that macrophages can influence FLS gene expression through a soluble mediator, and modulate the expression of an enzyme critical in osteoarthritis pathology during inflammatory stimulation. © 2018 The Authors. Journal of Orthopaedic Research® Published by WileyPeriodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 9999:1-8, 2018. © 2018 The Authors. Journal of Orthopaedic Research® Published by WileyPeriodicals, Inc. on behalf of the Orthopaedic Research Society.

Polyketide synthases of Diaporthe helianthi and involvement of DhPKS1 in virulence on sunflower.

PubMed

Ruocco, Michelina; Baroncelli, Riccardo; Cacciola, Santa Olga; Pane, Catello; Monti, Maurilia Maria; Firrao, Giuseppe; Vergara, Mariarosaria; Magnano di San Lio, Gaetano; Vannacci, Giovanni; Scala, Felice

2018-01-06

The early phases of Diaporthe helianthi pathogenesis on sunflower are characterized by the production of phytotoxins that may play a role in host colonisation. In previous studies, phytotoxins of a polyketidic nature were isolated and purified from culture filtrates of virulent strains of D. helianthi isolated from sunflower. A highly aggressive isolate (7/96) from France contained a gene fragment of a putative nonaketide synthase (lovB) which was conserved in a virulent D. helianthi population. In order to investigate the role of polyketide synthases in D. helianthi 7/96, a draft genome of this isolate was examined. We were able to find and phylogenetically analyse 40 genes putatively coding for polyketide synthases (PKSs). Analysis of their domains revealed that most PKS genes of D. helianthi are reducing PKSs, whereas only eight lacked reducing domains. Most of the identified PKSs have orthologs shown to be virulence factors or genetic determinants for toxin production in other pathogenic fungi. One of the genes (DhPKS1) corresponded to the previously cloned D. helianthi lovB gene fragment and clustered with a nonribosomal peptide synthetase (NRPS) -PKS hybrid/lovastatin nonaketide like A. nidulans LovB. We used DhPKS1 as a case study and carried out its disruption through Agrobacterium-mediated transformation in the isolate 7/96. D. helianthi DhPKS1 deleted mutants were less virulent to sunflower compared to the wild type, indicating a role for this gene in the pathogenesis of the fungus. The PKS sequences analysed and reported here constitute a new genomic resource that will be useful for further research on the biology, ecology and evolution of D. helianthi and generally of fungal plant pathogens.

Accuracy of reporting abortions with Down syndrome in England and Wales: a data linkage study.

PubMed

Morris, Joan K; Grinsted, Mary; Springett, Anna L

2016-03-01

The number of abortions of fetuses with Down syndrome in England and Wales reported by the Department of Health (DH) differs from that reported by the National Down Syndrome Cytogenetic Register (NDSCR). The aim of this study was to investigate the reasons for this. Abortions in 2011 and 2012 from DH were matched to those from NDSCR. The number of cases not reported to either source was estimated. An estimated 2240 abortions of fetuses with Down syndrome occurred in 2011/12; NDSCR estimated 2208 and DH 1100. One thousand and six abortions were identified in both data sets, including 145 (14%) which were not recorded by DH as having Down syndrome. Abortions in NDSCR that were not matched in DH occurred throughout England and Wales and at all gestational ages. An estimated 61 abortions of fetuses with Down syndrome were not reported to DH or NDSCR. The number of abortions of fetuses with Down syndrome reported by the NDSCR is more complete than that reported by the DH. DH data for abortions with other congenital anomalies are also likely to be underestimates, and more accurate estimates are available from BINOCAR regional congenital anomaly registers. © The Author 2015. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Evidence from Olivine-Hosted Melt Inclusions that the Martian Mantle has a Chondritic D/H Ratio and that Some Young Basalts have Assimilated Old Crust

NASA Technical Reports Server (NTRS)

Usui, Tomohiro; Alexander, O'D.; Wang, J.; Simon, J. I.; Jones, J. H.

2012-01-01

Magmatic degassing of volatile elements affects the climate and near-surface environment of Mars. Telescopic and meteorite studies have revealed that the Martian atmosphere and near-surface materials have D/H ratios 5-6 times terrestrial values [e.g., 1, 2]. Such high D/H ratios are interpreted to result from the preferential loss of H relative to heavier D from the Martian atmosphere, assuming that the original Martian water inventory had a D/H ratio similar to terrestrial values and to H in primitive meteorites [e.g., 1, 3]. However, the primordial Martian D/H ratio has, until now, not been well constrained. The uncertainty over the Martian primordial D/H ratio has arisen both from the scarcity of primitive Martian meteorites and as a result of contamination by terrestrial and, perhaps, Martian surface waters that obscure the signature of the Martian mantle. This study reports a comprehensive dataset of magmatic volatiles and D/H ratios in Martian primary magmas based on low-contamination, in situ ion microprobe analyses of olivine-hosted melt inclusions from both depleted [Yamato 980459 (Y98)] and enriched [Larkman Nunatak 06319 (LAR06)] Martian basaltic meteorites. Analyses of these primitive melts provide definitive evidence that the Martian mantle has retained a primordial D/H ratio and that young Martian basalts have assimilated old Martian crust.

Dihydro-CDDO-trifluoroethyl amide suppresses inflammatory responses in macrophages via activation of Nrf2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Bin; Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC 29208; Abdalrahman, Akram

2014-02-21

Highlights: • Dh404 suppresses the expression of a selected set of pro-inflammatory cytokines in inflamed macrophages via activating Nrf2. • Dh404 activates Nrf2 while keeping Keap1 function intact in macrophages. • Dh404 minimally regulates NF-κB pathway in macrophages. - Abstract: Nuclear factor erythroid 2-related factor (Nrf2) is the major regulator of cellular defenses against various pathological stresses in a variety of organ systems, thus Nrf2 has evolved to be an attractive drug target for the treatment and/or prevention of human disease. Several synthetic oleanolic triterpenoids including dihydro-CDDO-trifluoroethyl amide (dh404) appear to be potent activators of Nrf2 and exhibit chemopreventive promisesmore » in multiple disease models. While the pharmacological efficacy of Nrf2 activators may be dependent on the nature of Nrf2 activation in specific cell types of target organs, the precise role of Nrf2 in mediating biological effects of Nrf2 activating compounds in various cell types remains to be further explored. Herein we report a unique and Nrf2-dependent anti-inflammatory profile of dh404 in inflamed macrophages. In lipopolysaccharide (LPS)-inflamed RAW264.7 macrophages, dh404 dramatically suppressed the expression of pro-inflammatory cytokines including inducible nitric oxide synthase (iNOS), monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1 beta (MIP-1β), while minimally regulating the expression of interleulin-6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNFα). Dh404 potently activated Nrf2 signaling; however, it did not affect LPS-induced NF-κB activity. Dh404 did not interrupt the interaction of Nrf2 with its endogenous inhibitor Kelch-like ECH associating protein 1 (Keap1) in macrophages. Moreover, knockout of Nrf2 blocked the dh404-induced anti-inflammatory responses in LPS-inflamed macrophages. These results demonstrated that dh404 suppresses pro-inflammatory responses in macrophages via an activation of Nrf2 independently of Keap1 and NF-κB, suggesting a unique therapeutic potential of dh404 for specific targeting a Nrf2-mediated resolution of inflammation.« less

Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae) - A comparison with haploid males, queens and workers

PubMed Central

Borges, Andreia A.; Humann, Fernanda C.; Oliveira Campos, Lucio A.; Tavares, Mara G.; Hartfelder, Klaus

2011-01-01

In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males. PMID:22215977

Cutaneous expressions of interleukin-6 and neutrophil elastase as well as levels of serum IgA antibodies to gliadin nonapeptides, tissue transglutaminase and epidermal transglutaminase: implications for both autoimmunity and autoinflammation involvement in dermatitis herpetiformis.

PubMed

Gornowicz-Porowska, Justyna; Bowszyc-Dmochowska, Monika; Seraszek-Jaros, Agnieszka; Kaczmarek, Elżbieta; Pietkiewicz, Paweł; Dmochowski, Marian

2014-01-01

Dermatitis herpetiformis (DH) seems to be a chronic immune-mediated inflammatory disease of partially known origin. In light of its known biological functions and its involvement in tissue pathology in other disease states, particularly in nickel-induced allergic contact dermatitis coexisting with DH, it would appear that the central and peripheral response by neutrophils and their mediators (e.g. neutrophil elastase - NE) in DH may be partially mediated by interleukin-6 (IL-6). The aim of the study was to assess the role of IL -6 in DH lesions by examining the relationships between IL -6/NE cutaneous expression and levels of serum anti-nonapeptides of gliadin (npG) IgA, anti-tissue transglutaminase (tTG) immunoglobulin A (IgA), anti-epidermal transglutaminase (eTG) IgA in DH. In total, 24 DH patients having IgA cutaneous deposition were studied. Immunohistochemistry on paraffin-embedded sections with quantitative digital morphometry was used to measure the intensity of IL -6 and NE cutaneous expressions. Levels of serum anti-npG IgA, anti-tTG IgA and anti-eTG IgA were evaluated with ELISA. We found no statistically significant correlation between the NE and IL -6 expression intensities. Our results revealed also a lack of correlations between NE/IL -6 expressions and levels of anti-npG IgA, anti-tTG IgA, anti-eTG IgA in DH. However, the IL -6 expression level was significantly lower than that of NE. The lack of correlations suggested no substantial interactions between IL -6, NE, IgA/npG, IgA/tTG or IgA/eTG in DH. Presented results might indicate the heterogenetic nature of DH pathogenesis suggesting further that both autoimmune and autoinflammatory phenomena may be involved in DH cutaneous pathology.

13-cis-retinoic acid competitively inhibits 3 alpha-hydroxysteroid oxidation by retinol dehydrogenase RoDH-4: a mechanism for its anti-androgenic effects in sebaceous glands?

PubMed

Karlsson, Teresa; Vahlquist, Anders; Kedishvili, Natalia; Törmä, Hans

2003-03-28

Retinol dehydrogenase-4 (RoDH-4) converts retinol and 13-cis-retinol to corresponding aldehydes in human liver and skin in the presence of NAD(+). RoDH-4 also converts 3 alpha-androstanediol and androsterone into dihydrotestosterone and androstanedione, which may stimulate sebum secretion. This oxidative 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) activity of RoDH-4 is competitively inhibited by retinol and 13-cis-retinol. Here, we further examine the substrate specificity of RoDH-4 and the inhibition of its 3 alpha-HSD activity by retinoids. Recombinant RoDH-4 oxidized 3,4-didehydroretinol-a major form of vitamin A in the skin-to its corresponding aldehyde. 13-cis-retinoic acid (isotretinoin), 3,4-didehydroretinoic acid, and 3,4-didehydroretinol, but not all-trans-retinoic acid or the synthetic retinoids acitretin and adapalene, were potent competitive inhibitors of the oxidative 3 alpha-HSD activity of RoDH-4, i.e., reduced the formation of dihydrotestosterone and androstandione in vitro. Extrapolated to the in vivo situation, this effect might explain the unique sebosuppressive effect of isotretinoin when treating acne.

The Death of Superman: The Case Against Specialized Tanker Aircraft in the USAF

DTIC Science & Technology

2002-06-01

tanker and receiver aircraft were de Havilland DH -4Bs. The DH -4B was a single engine biplane with a gross weight of 3,557 pounds. Its cruising speed...including transport, air ambulance, photographic plane, trainer, target tug, forest fire patroller, and air racer. “De Havilland DH -4: Air Service... Havilland DH -4: Air Service Workhorse.” USAF Museum, WPAFB. On-line. Internet, 6 June 2002. Available from http://www.wpafb.af.mil/ museum

Geraniol dehydrogenase, the key enzyme in biosynthesis of the alarm pheromone, from the astigmatid mite Carpoglyphus lactis (Acari: Carpoglyphidae).

PubMed

Noge, Koji; Kato, Makiko; Mori, Naoki; Kataoka, Michihiko; Tanaka, Chihiro; Yamasue, Yuji; Nishida, Ritsuo; Kuwahara, Yasumasa

2008-06-01

Geraniol dehydrogenase (GeDH), which plays an important role in the biosynthesis of neral, an alarm pheromone, was purified from the astigmatid mite Carpoglyphus lactis. The enzyme was obtained in an apparently homogeneous and active form after 1879-fold purification through seven steps of chromatography. Car. lactis GeDH was determined to be a monomer in its active form with a relative molecular mass of 42 800, which is a unique subunit structure in comparison with already established alcohol dehydrogenases. Car. lactis GeDH oxidized geraniol into geranial in the presence of NAD+. NADP+ was ineffective as a cofactor, suggesting that Car. lactis GeDH is an NAD+-dependent alcohol dehydrogenase. The optimal pH and temperature for geraniol oxidation were determined to be pH 9.0 and 25 degrees C, respectively. The Km values for geraniol and NAD+ were 51.0 microm and 59.5 microm, respectively. Car. lactis GeDH was shown to selectively oxidize geraniol, whereas its geometrical isomer, nerol, was inert as a substrate. The high specificity for geraniol suggests that Car. lactis GeDH specializes in the alarm pheromone biosynthesis of Car. lactis. Car. lactis GeDH is composed of 378 amino acids. Structurally, Car. lactis GeDH showed homology with zinc-dependent alcohol dehydrogenases found in mammals and a mosquito (36.6-37.6% identical), and the enzyme was considered to be a member of the medium-chain dehydrogenase/reductase family, in view of the highly conserved sequences of zinc-binding and NAD+-binding sites. Phylogenetic analyses indicate that Car. lactis GeDH could be categorized as a new class, different from other established alcohol dehydrogenases.

NMDA-NO signaling in the dorsal and ventral hippocampus time-dependently modulates the behavioral responses to forced swimming stress.

PubMed

Diniz, Cassiano R A F; Casarotto, Plínio C; Joca, Sâmia R L

2016-07-01

Hodological and genetic differences between dorsal (DH) and ventral (VH) hippocampus may convey distinct behavioral roles. DH is responsible for mediating cognitive process, such as learning and memory, while VH modulates neuroendocrine and emotional-motivational responses to stress. Manipulating glutamatergic NMDA receptors and nitric oxide (NO) systems of the hippocampus induces important changes in behavioral responses to stress. Nevertheless, there is no study concerning functional differences between DH and VH in the modulation of behavioral responses induced by stress models predictive of antidepressant effects. Thus, this study showed that reversible blockade of the DH or VH of animals submitted to the forced swimming test (FST), by using cobalt chloride (calcium-dependent synaptic neurotransmission blocker), was not able to change immobility time. Afterwards, the NMDA-NO system was evaluated in the FST by means of intra-DH or intra-VH administration of NMDA receptor antagonist (AP7), NOS1 and sGC inhibitors (N-PLA and ODQ, respectively). Bilateral intra-DH injections after pretest or before test were able to induce antidepressant-like effects in the FST. On the other hand, bilateral VH administration of AP-7, N-PLA and ODQ induced antidepressant-like effects only when injected before the test. Administration of NO scavenger (C-PTIO) intra-DH, after pretest and before test, or intra-VH before test induced similar results. Increased NOS1 levels was associated to stress exposure in the DH. These results suggest that the glutamatergic-NO system of the DH and VH are both able to modulate behavioral responses in the FST, albeit with differential participation along time after stress exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

Dalitz analyses with B → Dh(h) decays at LHCb

NASA Astrophysics Data System (ADS)

Qian, Wenbin; LHCb Collaboration

2016-04-01

We present studies performed by the LHCb experiment with beauty to open charmed meson decays B → Dh (h (‧)), h (‧) = π , K. Using the 1 fb-1 results of B± →(hh (‧)) Dh±, 1 fb-1 results of B± →(K∓π±π+π-)Dh± and 1 fb-1 + 2 fb-1 results of model-independent Dalitz plot analysis of B± →(KShh)DK± modes, γ is constrained to be (67 ± 12) °. Further LHCb measurements with multi-body B or D decays are presented in the proceeding. The results include the model-dependent measurements of B± →(KShh)DK± and the CP violation measurements of B± →(KSKπ)Dh± and B →(hh (‧)) DK*0.

Nutrient Sensor in the Brain Directs the Action of the Brain-Gut Axis in Drosophila

PubMed Central

Dus, Monica; Sih-Yu Lai, Jason; Gunapala, Keith M.; Min, Soohong; Tayler, Timothy D.; Hergarden, Anne C.; Geraud, Eliot; Joseph, Christina M.; Suh, Greg S. B.

2015-01-01

Summary Animals can detect and consume nutritive sugars without the influence of taste. However, the identity of the taste-independent nutrient sensor and the mechanism by which animals respond to the nutritional value of sugar are unclear. Here, we report that six neurosecretory cells in the Drosophila brain that produce Diuretic hormone 44 (Dh44), a homologue of the mammalian corticotropin-releasing hormone (CRH), were specifically activated by nutritive sugars. Flies in which the activity of these neurons or the expression of Dh44 was disrupted failed to select nutritive sugars. Manipulation of the function of Dh44 receptors had a similar effect. Notably, artificial activation of Dh44 receptor-1 neurons resulted in proboscis extensions, and frequent episodes of excretion. Conversely, reduced Dh44 activity led to decreased excretion. Together, these actions facilitate ingestion and digestion of nutritive foods. We propose that the Dh44 system directs the detection and consumption of nutritive sugars through a positive feedback loop. PMID:26074004

Novel insights into the algicidal bacterium DH77-1 killing the toxic dinoflagellate Alexandrium tamarense.

PubMed

Yang, Xiaoru; Li, Xinyi; Zhou, Yanyan; Zheng, Wei; Yu, Changping; Zheng, Tianling

2014-06-01

Algicidal bacteria may play a major role in controlling harmful algal blooms (HABs) dynamics. Bacterium DH77-1 was isolated with high algicidal activity against the toxic dinoflagellate Alexandrium tamarense and identified as Joostella sp. DH77-1. The results showed that DH77-1 exhibited algicidal activity through indirect attack, which excreted active substance into the filtrate. It had a relatively wide host range and the active substance of DH77-1 was relatively stable since temperature, pH and storage condition had no obvious effect on the algicidal activity. The algicidal compound from bacterium DH77-1 was isolated based on activity-guided bioassay and the molecular weight was determined to be 125.88 by MALDI-TOF mass spectrometer, however further identification via nuclear magnetic resonance (NMR) spectra is ongoing. The physiological responses of algal cells after exposure to the DH77-1 algicidal substances were as follows: the antioxidant system of A. tamarense responded positively in self-defense; total protein content decreased significantly as did the photosynthetic pigment content; superoxide dismutase, peroxidase enzyme and malondialdehyde content increased extraordinarily and algal cell nucleic acid leaked seriously ultimately inducing cell death. Furthermore, DH77-1 is the first record of a Joostella sp. bacterium being algicidal to the harmful dinoflagellate A. tamarense, and the bacterial culture and the active compounds might be potentially used as a bio-agent for controlling harmful algal blooms. Copyright © 2014 Elsevier B.V. All rights reserved.

Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b.

PubMed

Gu, Wenyu; Farhan Ul Haque, Muhammad; DiSpirito, Alan A; Semrau, Jeremy D

2016-07-01

It is well known that Methylosinus trichosporium OB3b has two forms of methane monooxygenase (MMO) responsible for the initial conversion of methane to methanol, a cytoplasmic (soluble) methane monooxygenase and a membrane-associated (particulate) methane monooxygenase, and that copper strongly regulates expression of these alternative forms of MMO. More recently, it has been discovered that M. trichosporium OB3b has multiple types of the methanol dehydrogenase (MeDH), i.e. the Mxa-type MeDH (Mxa-MeDH) and Xox-type MeDH (Xox-MeDH), and the expression of these two forms is regulated by the availability of the rare earth element (REE), cerium. Here, we extend these studies and show that lanthanum, praseodymium, neodymium and samarium also regulate expression of alternative forms of MeDH. The effect of these REEs on MeDH expression, however, was only observed in the absence of copper. Further, a mutant of M. trichosporium OB3b, where the Mxa-MeDH was knocked out, was able to grow in the presence of lanthanum, praseodymium and neodymium, but was not able to grow in the presence of samarium. Collectively, these data suggest that multiple levels of gene regulation by metals exist in M. trichosporium OB3b, but that copper overrides the effect of other metals by an as yet unknown mechanism. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Anthocyanin biosynthesis regulation of DhMYB2 and DhbHLH1 in Dendrobium hybrids petals.

PubMed

Li, Chonghui; Qiu, Jian; Ding, Ling; Huang, Mingzhong; Huang, Surong; Yang, Guangsui; Yin, Junmei

2017-03-01

Dendrobium hybrids orchid are popular throughout the world. They have various floral color and pigmentation patterns that are mainly caused by anthocyanins. It is well established that anthocyanin biosynthesis is regulated by the interplay between MYB and bHLH transcription factors (TF) in most plants. In this study, we identified one R2R3-MYB gene, DhMYB2, and one bHLH gene, DhbHLH1, from a Dendrobium hybrid. Their expression profiles were related to anthocyanin pigmentation in Dendrobium petals. Transient over-expression of these two TF genes showed that both DhMYB2 and DhbHLH1 resulted in anthocyanin production in white petals. The interaction between the two TFs was observed in vitro. In different Dendrobium hybrids petals with various pigmentations, DhMYB2 and DhbHLH1 were co-expressed with DhDFR and DhANS, which are regarded as potential regulatory targets of the two TFs. In flowers with distinct purple lips but white or yellow petals/sepals, the expression of DhbHLH1 was only related to anthocyanin accumulation in the lips. Taken together, DhMYB2 interacted with DhbHLH1 to regulate anthocyanin production in Dendrobium hybrid petals. DhbHLH1 was also responsible for the distinct anthocyanin pigmentation in lip tissues. The functional characterization of DhMYB2 and DhbHLH1 will improve understanding of anthocyanin biosynthesis modulation in Dendrobium orchids. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

RADIATION INDUCED VIABILITY MUTATIONS IN THE HONEY BEE. Progress Report for 1961 and Renewal Proposal of Contract for 1962

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, W.R.

The spectrum of viability mutations ranging from dominant lethals to detrimentals in haploids that resulted from irradiating semen from a single haploid male was studied in the honey bee. From the decrease in viability of diploid progeny following irradiation of the spermatheca of the parental queen, it was calculated that one or more dominant lethals were induced in 60.8% of the sperm cells. In a separate test using the same dosage on an unrelated queen 60.9% dominant lethals were found. Recessive mutations and mutants with incomplete dominance were detected in haploid progeny of F-1 queens. (M.C.G.)

Use of the Polymerase Chain Reaction and Complementary DNA Probes in the Detection of Duchenne Muscular Dystrophy Carriers

DTIC Science & Technology

1990-01-01

dominant or X-linked mutations, for example DMD and lethal osteogenesis imperfecta (1, 97). This phenomenon is the result of a dual population of...of the mutations. Am J Hum Genet 1988; 43: 620-29. 97. Cohn DH, Starman B, Blumberg B, Byers PH. Recurrence of lethal osteogenesis imperfecta due to

Breeding of a xylose-fermenting hybrid strain by mating genetically engineered haploid strains derived from industrial Saccharomyces cerevisiae.

PubMed

Inoue, Hiroyuki; Hashimoto, Seitaro; Matsushika, Akinori; Watanabe, Seiya; Sawayama, Shigeki

2014-12-01

The industrial Saccharomyces cerevisiae IR-2 is a promising host strain to genetically engineer xylose-utilizing yeasts for ethanol fermentation from lignocellulosic hydrolysates. Two IR-2-based haploid strains were selected based upon the rate of xylulose fermentation, and hybrids were obtained by mating recombinant haploid strains harboring heterogeneous xylose dehydrogenase (XDH) (wild-type NAD(+)-dependent XDH or engineered NADP(+)-dependent XDH, ARSdR), xylose reductase (XR) and xylulose kinase (XK) genes. ARSdR in the hybrids selected for growth rates on yeast extract-peptone-dextrose (YPD) agar and YP-xylose agar plates typically had a higher activity than NAD(+)-dependent XDH. Furthermore, the xylose-fermenting performance of the hybrid strain SE12 with the same level of heterogeneous XDH activity was similar to that of a recombinant strain of IR-2 harboring a single set of genes, XR/ARSdR/XK. These results suggest not only that the recombinant haploid strains retain the appropriate genetic background of IR-2 for ethanol production from xylose but also that ARSdR is preferable for xylose fermentation.

The evolutionary dynamics of haplodiploidy: Genome architecture and haploid viability

PubMed Central

Blackmon, Heath; Hardy, Nate B.; Ross, Laura

2015-01-01

Haplodiploid reproduction, in which males are haploid and females are diploid, is widespread among animals, yet we understand little about the forces responsible for its evolution. The current theory is that haplodiploidy has evolved through genetic conflicts, as it provides a transmission advantage to mothers. Male viability is thought to be a major limiting factor; diploid individuals tend to harbor many recessive lethal mutations. This theory predicts that the evolution of haplodiploidy is more likely in male heterogametic lineages with few chromosomes, as genes on the X chromosome are often expressed in a haploid environment, and the fewer the chromosome number, the greater the proportion of the total genome that is X‐linked. We test this prediction with comparative phylogenetic analyses of mites, among which haplodiploidy has evolved repeatedly. We recover a negative correlation between chromosome number and haplodiploidy, find evidence that low chromosome number evolved prior to haplodiploidy, and that it is unlikely that diplodiploidy has reevolved from haplodiploid lineages of mites. These results are consistent with the predicted importance of haploid male viability. PMID:26462452

Ionotropic Glutamate Receptors and Voltage-Gated Ca2+ Channels in Long-Term Potentiation of Spinal Dorsal Horn Synapses and Pain Hypersensitivity

PubMed Central

Youn, Dong-ho; Gerber, Gábor; Sather, William A.

2013-01-01

Over the last twenty years of research on cellular mechanisms of pain hypersensitivity, long-term potentiation (LTP) of synaptic transmission in the spinal cord dorsal horn (DH) has emerged as an important contributor to pain pathology. Mechanisms that underlie LTP of spinal DH neurons include changes in the numbers, activity, and properties of ionotropic glutamate receptors (AMPA and NMDA receptors) and of voltage-gated Ca2+ channels. Here, we review the roles and mechanisms of these channels in the induction and expression of spinal DH LTP, and we present this within the framework of the anatomical organization and synaptic circuitry of the spinal DH. Moreover, we compare synaptic plasticity in the spinal DH with classical LTP described for hippocampal synapses. PMID:24224102

Evidence for primordial water in Earth's deep mantle.

PubMed

Hallis, Lydia J; Huss, Gary R; Nagashima, Kazuhide; Taylor, G Jeffrey; Halldórsson, Sæmundur A; Hilton, David R; Mottl, Michael J; Meech, Karen J

2015-11-13

The hydrogen-isotope [deuterium/hydrogen (D/H)] ratio of Earth can be used to constrain the origin of its water. However, the most accessible reservoir, Earth's oceans, may no longer represent the original (primordial) D/H ratio, owing to changes caused by water cycling between the surface and the interior. Thus, a reservoir completely isolated from surface processes is required to define Earth's original D/H signature. Here we present data for Baffin Island and Icelandic lavas, which suggest that the deep mantle has a low D/H ratio (δD more negative than -218 per mil). Such strongly negative values indicate the existence of a component within Earth's interior that inherited its D/H ratio directly from the protosolar nebula. Copyright © 2015, American Association for the Advancement of Science.

The D/H ratio in Saturn's atmosphere from Voyager IRIS spectra

NASA Technical Reports Server (NTRS)

Courtin, R.; Gautier, D.; Marten, A.; Bezard, B.; Hanel, R.

1985-01-01

A selection of 1656 spectra recorded between 180 and 2300 mm in the 20 to 40 N latitude range by the Voyager interferometer IRIS were analyzed. The CH3D/H2 and CH4/H2 ratios are determined from a best fit of the radiances measured in the nu6 and nu4 fundamental bands, respectively centered at 1161 and 1304 mm. Results are CH3D/H2 = 3.9 + or - 2.5 times 10 to the minus 7th power and CH4/H2 = 4.5 + 2.4, -1.9 x 0.001. The uncertainty includes random errors due to instrumental noise and possible systematic errors in the assumed temperature profile and spectroscopic parameters. The D/H isotopic ratio is determined from abundance ratios from the expression D/H = 1/4f (CH3D/H2)/(CH4/H2) where f accounts for equilibrium deuterium fractionation between the molecular hydrogen and methane phases. Beer and Taylor (1973, 1978) estimated f = 1.37 + or - 0.07 for Jupiter assuming a wide range of convective velocities and neglecting catalytic effects from dust particles. The same value was adopted for Saturn and yields D/H = 1.6 +1.3, -1.2 times 10 to the minus 5th power.

[Comparative study on promoting blood effects of Danshen-Honghua herb pair with different preparations based on chemometrics and multi-attribute comprehensive index methods].

PubMed

Qu, Cheng; Tang, Yu-Ping; Shi, Xu-Qin; Zhou, Gui-Sheng; Shang, Er-Xin; Shang, Li-Li; Guo, Jian-Ming; Liu, Pei; Zhao, Jing; Zhao, Bu-Chang; Duan, Jin-Ao

2017-08-01

To evaluate the promoting blood circulation and removing blood stasis effects of Danshen-Honghua(DH) herb pair with different preparations (alcohol, 50% alcohol and water) on blood rheology and coagulation functions in acute blood stasis rats, and optimize the best preparation method of DH based on principal component analysis(PCA), hierarchical cluster heatmap analysis and multi-attribute comprehensive index methods. Ice water bath and subcutaneous injection of adrenaline were both used to establish the acute blood stasis rat model. Then the blood stasis rats were administrated intragastrically with DH (alcohol, 50% alcohol and water) extracts. The whole blood viscosity(WBV), plasma viscosity(PV), erythrocyte sedimentation rate(ESR) and haematocrit(HCT) were tested to observe the effects of DH herb pair with different preparations and doses on hemorheology of blood stasis rats; the activated partial thromboplastin time(APTT), thrombin time(TT), prothrombin time(PT), and plasma fibrinogen(FIB) were tested to observe the effects of DH herb pair with different preparations on blood coagulation function and platelet aggregation of blood stasis rats. Then PCA, hierarchical cluster heatmap analysis and multi-attribute comprehensive index methods were all used to comprehensively evaluate the total promoting blood circulation and removing blood stasis effects of DH herb pair with different preparations. The hemorheological indexes and coagulation parameters of model group had significant differences with normal blank group. As compared with the model group, the DH herb pair with different preparations at low, middle and high doses could improve the blood hemorheology indexes and coagulation parameters in acute blood stasis rats with dose-effect relation. Based on the PCA, hierarchical cluster heatmap analysis and multi-attribute comprehensive index methods, the high dose group of 50% alcohol extract had the best effect of promoting blood circulation and removing blood stasis. Under the same dose but different preparations, 50% alcohol DH could obviously improve the hemorheology and blood coagulation function in acute blood stasis rats. These results suggested that DH herb pair with different preparations could obviously ameliorate the abnormality of hemorheology and blood coagulation function in acute blood stasis rats, and the optimized preparation of DH herb pair on promoting blood effects was 50% alcohol extract, providing scientific basis for more effective application of the DH herb pair in modern clinic medicine. Copyright© by the Chinese Pharmaceutical Association.

Single-gene deletions that restore mating competence to diploid yeast.

PubMed

Schmidlin, Tom; Kaeberlein, Matt; Kudlow, Brian A; MacKay, Vivian; Lockshon, Daniel; Kennedy, Brian K

2008-03-01

Using the Saccharomyces cerevisiae MATa/MATalpha ORF deletion collection, homozygous deletion strains were identified that undergo mating with MATa or MATalpha haploids. Seven homozygous deletions were identified that confer enhanced mating. Three of these, lacking CTF8, CTF18, and DCC1, mate at a low frequency with either MATa or MATalpha haploids. The products of these genes form a complex involved in sister chromatid cohesion. Each of these strains also exhibits increased chromosome loss rates, and mating likely occurs due to loss of one copy of chromosome III, which bears the MAT locus. Three other homozygous diploid deletion strains, ylr193cDelta/ylr193cDelta, yor305wDelta/yor305wDelta, and ypr170cDelta/ypr170cDelta, mate at very low frequencies with haploids of either or both mating types. However, an ist3Delta/ist3Delta strain mates only with MATa haploids. It is shown that IST3, previously linked to splicing, is required for efficient processing of the MATa1 message, particularly the first intron. As a result, the ist3Delta/ist3Delta strain expresses unbalanced ratios of Matalpha to Mata proteins and therefore mates with MATa haploids. Accordingly, mating in this diploid can be repressed by introduction of a MATa1 cDNA. In summary, this study underscores and elaborates upon predicted pathways by which mutations restore mating function to yeast diploids and identifies new mutants warranting further study.

Most recent common ancestor probability distributions in gene genealogies under selection.

PubMed

Slade, P F

2000-12-01

A computational study is made of the conditional probability distribution for the allelic type of the most recent common ancestor in genealogies of samples of n genes drawn from a population under selection, given the initial sample configuration. Comparisons with the corresponding unconditional cases are presented. Such unconditional distributions differ from samples drawn from the unique stationary distribution of population allelic frequencies, known as Wright's formula, and are quantified. Biallelic haploid and diploid models are considered. A simplified structure for the ancestral selection graph of S. M. Krone and C. Neuhauser (1997, Theor. Popul. Biol. 51, 210-237) is enhanced further, reducing the effective branching rate in the graph. This improves efficiency of such a nonneutral analogue of the coalescent for use with computational likelihood-inference techniques.

Quantitative Trait Loci Mapping of Western Corn Rootworm (Coleoptera: Chrysomelidae) Host Plant Resistance in Two Populations of Doubled Haploid Lines in Maize (Zea mays L.).

PubMed

Bohn, Martin O; Marroquin, Juan J; Flint-Garcia, Sherry; Dashiell, Kenton; Willmot, David B; Hibbard, Bruce E

2018-02-09

Over the last 70 yr, more than 12,000 maize accessions have been screened for their level of resistance to western corn rootworm, Diabrotica virgifera virgifera (LeConte; Coleoptera: Chrysomelidae), larval feeding. Less than 1% of this germplasm was selected for initiating recurrent selection or other breeding programs. Selected genotypes were mostly characterized by large root systems and superior root regrowth after root damage caused by western corn rootworm larvae. However, no hybrids claiming native (i.e., host plant) resistance to western corn rootworm larval feeding are currently commercially available. We investigated the genetic basis of western corn rootworm resistance in maize materials with improved levels of resistance using linkage disequilibrium mapping approaches. Two populations of topcrossed doubled haploid maize lines (DHLs) derived from crosses between resistant and susceptible maize lines were evaluated for their level of resistance in three to four different environments. For each DHL topcross an average root damage score was estimated and used for quantitative trait loci (QTL) analysis. We found genomic regions contributing to western corn rootworm resistance on all maize chromosomes, except for chromosome 4. Models fitting all QTL simultaneously explained about 30 to 50% of the genotypic variance for root damage scores in both mapping populations. Our findings confirm the complex genetic structure of host plant resistance against western corn rootworm larval feeding in maize. Interestingly, three of these QTL regions also carry genes involved in ascorbate biosynthesis, a key compound we hypothesize is involved in the expression of western corn rootworm resistance. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Investigation of the microbial community in the Odisha hot spring cluster based on the cultivation independent approach.

PubMed

Singh, Archana; Subudhi, Enketeswara; Sahoo, Rajesh Kumar; Gaur, Mahendra

2016-03-01

Deulajhari hot spring is located in the Angul district of Odisha. The significance of this hot spring is the presence of the hot spring cluster adjacent to the cold spring which attracts the attention of microbiologists to understand the role of physio-chemical factors of these springs on bacterial community structure. Next-generation sequencing technology helps us to depict the pioneering microflora of any ecological niche based on metagenomic approach. Our study represents the first Illumina based metagenomic study of Deulajhari hot spring DH1, and DH2 of the cluster with temperature 65 °C to 55 °C respectively establishing a difference of 10 °C. Comprehensive study of microbiota of these two hot springs was done using the metagenomic sequencing of 16S rRNA of V3-V4 region extracting metagenomic DNA from the two hot spring sediments. Sequencing community DNA reported about 28 phyla in spring DH1 of which the majority were Chloroflexi (22.98%), Proteobacteria (15.51%), Acidobacteria (14.51%), Chlorobi (9.52%), Nitrospirae (8.54%), and Armatimonadetes (7.07%), at the existing physiochemical conditions like; temperature 65 °C, pH 8.06, electro conductivity 0.020 dSm(- 1), and total organic carbon (TOC) 3.76%. About 40 phyla were detected in cluster DH2 at the existing physiochemical parameters like temperature 55 °C, pH 8.10, electro conductivity 0.019 dSm(- 1), and total organic carbon (TOC) 0.58% predominated with Chloroflexi (41.98%), Proteobacteria (10.74%), Nitrospirae (10.01%), Chlorobi (8.73%), Acidobacteria (6.73%) and Planctomycetes (3.73%). Approximately 68 class, 107 order, 171 genus and 184 species were reported in cluster DH1 but 102 class, 180 order, 375 genus and 411 species in cluster DH2. The comparative metagenomics study of the Deulajhari hot spring clusters DH1, and DH2 depicts the differential profile of the microbiota. Metagenome sequences of these two hot spring clusters are deposited to the SRA database and are available in NCBI with accession no. SRX1459734 for DH1 and SRX1459735 for DH2.

Comparison of acute countermovement jump responses after functional isometric and dynamic half squats.

PubMed

Boyd, David A; Donald, Neil; Balshaw, Thomas G

2014-12-01

The purpose of this study was to compare acute countermovement jump (CMJ) responses after functional isometric (FI) and dynamic half (DH) squats. Ten strength-trained males (relative full back squat 1 repetition maximum [1RM]: 1.9 ± 0.2) participated in a randomized crossover design study. On 2 separate days, participants performed baseline CMJs followed by either FI or DH squats loaded with 150% of full back squat 1RM. Further CMJs were performed between 2 and 11 minutes after FI or DH squats. Kinematic and kinetic CMJ variables were measured. There were no differences observed between conditions when peak CMJ variables after FI or DH squats were compared with baseline values (p > 0.05). Countermovement jump time effects (p ≤ 0.05) were observed after squats. Increases in peak force (p ≤ 0.05; FI: 3.9%, range: -0.9 to 9.1%; DH: 4.2%, range: 0.0-11.5%) and decreases in peak power (p ≤ 0.05; FI: -0.4%, range: -5.1 to 4.0%; DH: -1.1%, range: -6.6 to 2.9%) occurred for combined condition data. Positive correlations between lower-body strength and the extent or timing of acute CMJ responses were not detected (p > 0.05). Because of the apparent lack of additive acute CMJ responses, the use of conventional DH squat protocols should be considered rather than FI squats in precompetition and training situations. Furthermore, the establishment of individual FI and DH squat protocols also seems to be necessary, rather than relying on relative lower-body strength to predict the nature of acute CMJ responses.

A novel archaeal alanine dehydrogenase homologous to ornithine cyclodeaminase and mu-crystallin.

PubMed

Schröder, Imke; Vadas, Alexander; Johnson, Eric; Lim, Sierin; Monbouquette, Harold G

2004-11-01

A novel alanine dehydrogenase (AlaDH) showing no significant amino acid sequence homology with previously known bacterial AlaDHs was purified to homogeneity from the soluble fraction of the hyperthermophilic archaeon Archaeoglobus fulgidus. AlaDH catalyzed the reversible, NAD+-dependent deamination of L-alanine to pyruvate and NH4+. NADP(H) did not serve as a coenzyme. The enzyme is a homodimer of 35 kDa per subunit. The Km values for L-alanine, NAD+, pyruvate, NADH, and NH4+ were estimated at 0.71, 0.60, 0.16, 0.02, and 17.3 mM, respectively. The A. fulgidus enzyme exhibited its highest activity at about 82 degrees C (203 U/mg for reductive amination of pyruvate) yet still retained 30% of its maximum activity at 25 degrees C. The thermostability of A. fulgidus AlaDH was increased by more than 10-fold by 1.5 M KCl to a half-life of 55 h at 90 degrees C. At 25 degrees C in the presence of this salt solution, the enzyme was approximately 100% stable for more than 3 months. Closely related A. fulgidus AlaDH homologues were found in other archaea. On the basis of its amino acid sequence, A. fulgidus AlaDH is a member of the ornithine cyclodeaminase-mu-crystallin family of enzymes. Similar to the mu-crystallins, A. fulgidus AlaDH did not exhibit any ornithine cyclodeaminase activity. The recombinant human mu-crystallin was assayed for AlaDH activity, but no activity was detected. The novel A. fulgidus gene encoding AlaDH, AF1665, is designated ala.

Does degree of handedness in a group of right-handed individuals affect language comprehension?

PubMed

Newman, Sharlene; Malaia, Evie; Seo, Roy

2014-04-01

The impact of handedness on language processing has been studied extensively and the results indicate that there is a relationship between the two variables; however, the nature of the relationship is not at all clear. In the current study we explored degree of handedness (DH) opposed to direction in a group of right-handed individuals. fMRI was used to explore the impact of DH on the sentence comprehension network. The results revealed that during sentence comprehension activation in regions linked to semantic memory (e.g., anterior temporal cortex) were modulated by DH. Also, unexpectedly the precuneus/posterior cingulate gyrus which has been linked to episodic memory was also affected by DH. These results extend those reported previously by showing that the neural architecture that supports sentence comprehension is modulated by DH. More specifically, together the results presented here support the hypothesis proposed by Townsend, Carrithers, and Bever (2001) that DH interacts with the language system and impacts the strategy used during sentence comprehension. Copyright © 2014 Elsevier Inc. All rights reserved.

Calcitonin receptors are ancient modulators for rhythms of preferential temperature in insects and body temperature in mammals.

PubMed

Goda, Tadahiro; Doi, Masao; Umezaki, Yujiro; Murai, Iori; Shimatani, Hiroyuki; Chu, Michelle L; Nguyen, Victoria H; Okamura, Hitoshi; Hamada, Fumika N

2018-01-15

Daily body temperature rhythm (BTR) is essential for maintaining homeostasis. BTR is regulated separately from locomotor activity rhythms, but its molecular basis is largely unknown. While mammals internally regulate BTR, ectotherms, including Drosophila , exhibit temperature preference rhythm (TPR) behavior to regulate BTR. Here, we demonstrate that the diuretic hormone 31 receptor (DH31R) mediates TPR during the active phase in Drosophila DH31R is expressed in clock cells, and its ligand, DH31, acts on clock cells to regulate TPR during the active phase. Surprisingly, the mouse homolog of DH31R, calcitonin receptor (Calcr), is expressed in the suprachiasmatic nucleus (SCN) and mediates body temperature fluctuations during the active phase in mice. Importantly, DH31R and Calcr are not required for coordinating locomotor activity rhythms. Our results represent the first molecular evidence that BTR is regulated distinctly from locomotor activity rhythms and show that DH31R/Calcr is an ancient specific mediator of BTR during the active phase in organisms ranging from ectotherms to endotherms. © 2018 Goda et al.; Published by Cold Spring Harbor Laboratory Press.

In vivo Three-Dimensional Superresolution Fluorescence Tracking using a Double-Helix Point Spread Function

PubMed Central

Lew, Matthew D.; Thompson, Michael A.; Badieirostami, Majid; Moerner, W. E.

2010-01-01

The point spread function (PSF) of a widefield fluorescence microscope is not suitable for three-dimensional super-resolution imaging. We characterize the localization precision of a unique method for 3D superresolution imaging featuring a double-helix point spread function (DH-PSF). The DH-PSF is designed to have two lobes that rotate about their midpoint in any transverse plane as a function of the axial position of the emitter. In effect, the PSF appears as a double helix in three dimensions. By comparing the Cramer-Rao bound of the DH-PSF with the standard PSF as a function of the axial position, we show that the DH-PSF has a higher and more uniform localization precision than the standard PSF throughout a 2 μm depth of field. Comparisons between the DH-PSF and other methods for 3D super-resolution are briefly discussed. We also illustrate the applicability of the DH-PSF for imaging weak emitters in biological systems by tracking the movement of quantum dots in glycerol and in live cells. PMID:20563317

Dose dependence of the excision of ultraviolet-induced pyrimidine dimers from nuclear deoxyribonucleic acids of haploid and diploid Saccharomyces cerevisiae.

PubMed Central

Waters, R; Moustacchi, E

1975-01-01

The yield of ultraviolet-induced dimers is similar for a fixed dose in both haploid and diploid Saccharomyces cerevisiae. The excision of these photo-products from the nuclear deoxyribonucleic acids of cells of both ploidies after ultraviolet incident doses of 2 times 10-3 to 4 times 10-3 ergs/mm2 decreased with the corresponding increasing dose. Postirradiation incubation in saline followed by a further incubation in nutrient medium increases the excision as compared to that seen in either nutrient medium or saline alone. Previous data regarding both pyrimidine dimer removal and the survival of haploid and diploid cells after ultraviolet irradiation and either immediate or delayed plating are discussed. PMID:1090608

Efficacy and safety of a medication dose reminder feature in a digital health offering with the use of sensor-enabled medicines.

PubMed

Moorhead, Penjit; Zavala, Ana; Kim, Yoona; Virdi, Naunihal S

Over one-half of patients with chronic diseases, such as hypertension and type 2 diabetes (DM), do not take medicines as prescribed. This study assessed the efficacy and safety of "seeing" versus "not seeing" medication dose reminders regarding medication adherence and risk for overdose. Post hoc analysis. Outpatient setting. Adult subjects (18 years of age or older) with uncontrolled hypertension and DM. Subjects enrolled in this institutional review board-approved study were assigned to either use digital health (DH) with the use of sensor-enabled medicines (coencapsulated medicines with an ingestible sensor) for 4 or 12 weeks or receive usual care based on a cluster-randomized design. All subjects were followed for 12 weeks. Subjects using DH were included in the post hoc study consisting of an efficacy analysis and a safety analysis. A main efficacy outcome of comparison of subjects taking medicine with or without "seeing" DH medication dose reminders was assessed. Safety analysis assessed risk of overdosing after DH medication dose reminders. In 57 subjects included in the efficacy analysis, DH device reminder messages were associated with a 16 ± 16% increase (75 ± 18% when seeing vs. 59 ± 24% when not seeing mobile dose reminders) in medication taking if not taken before dose reminder. The mean overall adherence for all subjects was 86 ± 12%; the mean on-time adherence was 69.7 ± 19.7%. Subjects with lower adherence benefited more from seeing DH reminder messages. In the safety study (n = 74 subjects and 24,426 medication ingestions), no events of overdoses related to DH medication dose reminders occurred. This study demonstrates benefits of DH medication dose reminders to improve medication adherence, especially in patients with lower adherence; DH medication dose reminders also appear to be safe. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Growth and characterization of AlGaN/GaN/AlGaN double-heterojunction high-electron-mobility transistors on 100-mm Si(111) using ammonia-molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ravikiran, L.; Radhakrishnan, K., E-mail: ERADHA@ntu.edu.sg; Yiding, Lin

2015-01-14

To improve the confinement of two-dimensional electron gas (2DEG) in AlGaN/GaN high electron mobility transistor (HEMT) heterostructures, AlGaN/GaN/AlGaN double heterojunction HEMT (DH-HEMT) heterostructures were grown using ammonia-MBE on 100-mm Si substrate. Prior to the growth, single heterojunction HEMT (SH-HEMT) and DH-HEMT heterostructures were simulated using Poisson-Schrödinger equations. From simulations, an AlGaN buffer with “Al” mole fraction of 10% in the DH-HEMT was identified to result in both higher 2DEG concentration (∼10{sup 13 }cm{sup −2}) and improved 2DEG confinement in the channel. Hence, this composition was considered for the growth of the buffer in the DH-HEMT heterostructure. Hall measurements showed a roommore » temperature 2DEG mobility of 1510 cm{sup 2}/V.s and a sheet carrier concentration (n{sub s}) of 0.97 × 10{sup 13 }cm{sup −2} for the DH-HEMT structure, while they are 1310 cm{sup 2}/V.s and 1.09 × 10{sup 13 }cm{sup −2}, respectively, for the SH-HEMT. Capacitance-voltage measurements confirmed the improvement in the confinement of 2DEG in the DH-HEMT heterostructure, which helped in the enhancement of its room temperature mobility. DH-HEMT showed 3 times higher buffer break-down voltage compared to SH-HEMT, while both devices showed almost similar drain current density. Small signal RF measurements on the DH-HEMT showed a unity current-gain cut-off frequency (f{sub T}) and maximum oscillation frequency (f{sub max}) of 22 and 25 GHz, respectively. Thus, overall, DH-HEMT heterostructure was found to be advantageous due to its higher buffer break-down voltages compared to SH-HEMT heterostructure.« less

Dentine sensitivity risk factors: A case-control study.

PubMed

Mafla, Ana Cristina; Lopez-Moncayo, Luis Fernando

2016-01-01

To identify the clinical and psychological risk factors associated with dentine hypersensitivity (DH) in order to provide an early diagnosis and preventive therapy. A nested case-control study was design between 2011 and 2012. A total of 61 DH cases and 122 controls participated in this investigation. Cases and controls were matched for sex, group of age and socioeconomic status in a ratio of 1:2. DH to different stimuli such as cold, heat, acid, and sweet was asked in patient interviews, and dental examinations were used to detect DH. Clinical and psychological risk factors such as dental hygiene, periodontal disease, acid diet, alcohol consumption, psychological stress, and psychopathological symptoms were inquired. Psychological stress was measured through the PSS-10 and psychopathological symptoms were evaluated by SCL-90-R in Spanish. Descriptive and univariate binary logistic regression analysis were performed to estimate the association between clinical and psychological risk factors and the presence of DH. Toothpaste abrasivity (odds ratio [OR] 1.881, 95% confidence interval [CI] 1.010-3.502, P = 0.045), gingival recession (OR 2.196, 95% CI 1.020-4.728, P = 0.041), and periodontal therapy (OR 5.357, 95% CI 2.051-13.993, P < 0.001) were associated with DH. Subjects with perceived stress (OR 1.211, 95%, CI 0.518-2.833, P = 0.658), obsessive-compulsive (OR 1.266, 95%, CI 0.494-3.240, P = 0.623) and hostility (OR 1.235, 95%, CI 0.507-3.007, P = 0.642) symptoms had a clinical greater odd of DH. Oral hygiene products and periodontal conditions are important risk factors for DH. Individuals with perceived stress, obsessive-compulsive, and hostility symptoms may increase a clinical risk for this entity. Targeting to dental counseling focused on oral hygiene products, periodontal therapy and a psychological evaluation may be promising in DH prevention.

Dentine sensitivity risk factors: A case–control study

PubMed Central

Mafla, Ana Cristina; Lopez-Moncayo, Luis Fernando

2016-01-01

Objective: To identify the clinical and psychological risk factors associated with dentine hypersensitivity (DH) in order to provide an early diagnosis and preventive therapy. Materials and Methods: A nested case–control study was design between 2011 and 2012. A total of 61 DH cases and 122 controls participated in this investigation. Cases and controls were matched for sex, group of age and socioeconomic status in a ratio of 1:2. DH to different stimuli such as cold, heat, acid, and sweet was asked in patient interviews, and dental examinations were used to detect DH. Clinical and psychological risk factors such as dental hygiene, periodontal disease, acid diet, alcohol consumption, psychological stress, and psychopathological symptoms were inquired. Psychological stress was measured through the PSS-10 and psychopathological symptoms were evaluated by SCL-90-R in Spanish. Descriptive and univariate binary logistic regression analysis were performed to estimate the association between clinical and psychological risk factors and the presence of DH. Results: Toothpaste abrasivity (odds ratio [OR] 1.881, 95% confidence interval [CI] 1.010–3.502, P = 0.045), gingival recession (OR 2.196, 95% CI 1.020–4.728, P = 0.041), and periodontal therapy (OR 5.357, 95% CI 2.051–13.993, P < 0.001) were associated with DH. Subjects with perceived stress (OR 1.211, 95%, CI 0.518–2.833, P = 0.658), obsessive-compulsive (OR 1.266, 95%, CI 0.494–3.240, P = 0.623) and hostility (OR 1.235, 95%, CI 0.507–3.007, P = 0.642) symptoms had a clinical greater odd of DH. Conclusion: Oral hygiene products and periodontal conditions are important risk factors for DH. Individuals with perceived stress, obsessive-compulsive, and hostility symptoms may increase a clinical risk for this entity. Targeting to dental counseling focused on oral hygiene products, periodontal therapy and a psychological evaluation may be promising in DH prevention. PMID:27011732

Structural and kinetic studies of a novel nerol dehydrogenase from Persicaria minor, a nerol-specific enzyme for citral biosynthesis.

PubMed

Tan, Cheng Seng; Hassan, Maizom; Mohamed Hussein, Zeti Azura; Ismail, Ismanizan; Ho, Kok Lian; Ng, Chyan Leong; Zainal, Zamri

2018-02-01

Geraniol degradation pathway has long been elucidated in microorganisms through bioconversion studies, yet weakly characterised in plants; enzyme with specific nerol-oxidising activity has not been reported. A novel cDNA encodes nerol dehydrogenase (PmNeDH) was isolated from Persicaria minor. The recombinant PmNeDH (rPmNeDH) is a homodimeric enzyme that belongs to MDR (medium-chain dehydrogenases/reductases) superfamily that catalyses the first oxidative step of geraniol degradation pathway in citral biosynthesis. Kinetic analysis revealed that rPmNeDH has a high specificity for allylic primary alcohols with backbone ≤10 carbons. rPmNeDH has ∼3 fold higher affinity towards nerol (cis-3,7-dimethyl-2,6-octadien-1-ol) than its trans-isomer, geraniol. To our knowledge, this is the first alcohol dehydrogenase with higher preference towards nerol, suggesting that nerol can be effective substrate for citral biosynthesis in P. minor. The rPmNeDH crystal structure (1.54 Å) showed high similarity with enzyme structures from MDR superfamily. Structure guided mutation was conducted to describe the relationships between substrate specificity and residue substitutions in the active site. Kinetics analyses of wild-type rPmNeDH and several active site mutants demonstrated that the substrate specificity of rPmNeDH can be altered by changing any selected active site residues (Asp 280 , Leu 294 and Ala 303 ). Interestingly, the L294F, A303F and A303G mutants were able to revamp the substrate preference towards geraniol. Furthermore, mutant that exhibited a broader substrate range was also obtained. This study demonstrates that P. minor may have evolved to contain enzyme that optimally recognise cis-configured nerol as substrate. rPmNeDH structure provides new insights into the substrate specificity and active site plasticity in MDR superfamily. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Effect of precipitation, geographical location and biosynthesis on New Zealand milk powder bulk and fatty acids D/H ratios

NASA Astrophysics Data System (ADS)

Frew, R.; Emad Ehtesham, R.; Van Hale, R.; Hayman, A.; Baisden, T.

2012-04-01

D/H ratio measurements provide useful information for the investigation of biogeochemical influences on natural and agricultural produce, particularly with application to food traceability and authentication. Numerous studies have shown that variation of a product's D/H ratio is influenced by both environmental factors and biological processes. This study investigates the D/H ratio of New Zealand milk powder and individual fatty acids, and causal determinants of isotopic variation. One of the key environmental factors is precipitation, and the D/H ratio "isoscaping" of NZ has been undertaken. New Zealand provides a unique geography for these kinds of study in terms of proximity to the ocean and natural geographical variability from sea level to elevations as high as 3700 m. Milk powder samples were collected from different geographical regions from milk processing units, which were supplied by producers in the immediate region. H/D ratios of bulk milk powder and of individual fatty acids were determined. Initial comparison of the precipitation and milk powder bulk D/H data show a very good differentiation from north to southernmost parts of New Zealand and a relation between rain and milk bulk D/H abundance ratio. Almost 98% of milk FAs are in the form of triglycerides that have been extracted and hydrolysed to free FAs. Free FAs were esterified and analyzed with GC-IRMS. Individual FAs show variation in D/H ratio, and all values are depleted relative to the precipitation data. The difference in D/H ratio amongst individual FAs reflects the geographical environment and biological processes i.e. micro-organisms activity in the rumen of the cow. Short chain FAs (less than 8 carbons), particularly C4 (Butyric acid), appear to be key determinants. The variation in the data can be rationalized using statistical multivariate analysis.

Identification of sequence-related amplified polymorphism markers linked to the red leaf trait in ornamental kale (Brassica oleracea L. var. acephala).

PubMed

Wang, Y S; Liu, Z Y; Li, Y F; Zhang, Y; Yang, X F; Feng, H

2013-04-02

Artistic diversiform leaf color is an important agronomic trait that affects the market value of ornamental kale. In the present study, genetic analysis showed that a single-dominant gene, Re (red leaf), determines the red leaf trait in ornamental kale. An F2 population consisting of 500 individuals from the cross of a red leaf double-haploid line 'D05' with a white leaf double-haploid line 'D10' was analyzed for the red leaf trait. By combining bulked segregant analysis and sequence-related amplified polymorphism technology, we identified 3 markers linked to the Re/re locus. A genetic map of the Re locus was constructed using these sequence-related amplified polymorphism markers. Two of the markers, Me8Em4 and Me8Em17, were located on one side of Re/re at distances of 2.2 and 6.4 cM, whereas the other marker, Me9Em11, was located on the other side of Re/re at a distance of 3.7 cM. These markers could be helpful for the subsequent cloning of the red trait gene and marker-assisted selection in ornamental kale breeding programs.

Sequencing of Single Pollen Nuclei Reveals Meiotic Recombination Events at Megabase Resolution and Circumvents Segregation Distortion Caused by Postmeiotic Processes

PubMed Central

Dreissig, Steven; Fuchs, Jörg; Himmelbach, Axel; Mascher, Martin; Houben, Andreas

2017-01-01

Meiotic recombination is a fundamental mechanism to generate novel allelic combinations which can be harnessed by breeders to achieve crop improvement. The recombination landscape of many crop species, including the major crop barley, is characterized by a dearth of recombination in 65% of the genome. In addition, segregation distortion caused by selection on genetically linked loci is a frequent and undesirable phenomenon in double haploid populations which hampers genetic mapping and breeding. Here, we present an approach to directly investigate recombination at the DNA sequence level by combining flow-sorting of haploid pollen nuclei of barley with single-cell genome sequencing. We confirm the skewed distribution of recombination events toward distal chromosomal regions at megabase resolution and show that segregation distortion is almost absent if directly measured in pollen. Furthermore, we show a bimodal distribution of inter-crossover distances, which supports the existence of two classes of crossovers which are sensitive or less sensitive to physical interference. We conclude that single pollen nuclei sequencing is an approach capable of revealing recombination patterns in the absence of segregation distortion. PMID:29018459

A study of the influence of different genotypes on the physical and behavioral phenotypes of children and adults ascertained clinically as having PWS.

PubMed

Webb, T; Whittington, J; Clarke, D; Boer, H; Butler, J; Holland, A

2002-10-01

A population-based cohort of people with a clinical diagnosis of Prader-Willi syndrome (PWS) was genetically assessed using molecular diagnostic methods and subsequently divided into the following genetic subtypes involving chromosome 15: 'deletion', 'disomy' and genetically negative (referred to as 'PWS-like'). The physical and behavioral characteristics of the three groups were compared in order to evaluate the unique characteristics of the phenotype resulting from loss of expression of imprinted genes at 15q11q13 (PWS vs. PWS-like cases), the possible effect of either haploid insufficiency of non-imprinted genes (deletion cases), or gain of function of imprinted genes (disomy cases) located within the PWS critical region at 15q11q13. In this study, the main differences between probands with either a deletion or disomy are considered, and the possible involvement of contributing genes discussed. The differences within the PWS group proved difficult to quantify. It would appear that haploid insufficiency or gain of function are more subtle contributors than gender-specific genomic imprinting in the production of the PWS phenotype.

Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/−-IRS-1+/− Double Heterozygous (IR-IRS1dh) Mice

PubMed Central

Franko, Andras; Kunze, Alexander; Böse, Marlen; von Kleist-Retzow, Jürgen-Christoph; Paulsson, Mats; Hartmann, Ursula; Wiesner, Rudolf J.

2017-01-01

Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR)+/−-insulin receptor substrate-1 (IRS-1)+/− double heterozygous (IR-IRS1dh) mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver. PMID:28556799

Impaired Insulin Signaling is Associated with Hepatic Mitochondrial Dysfunction in IR+/--IRS-1+/- Double Heterozygous (IR-IRS1dh) Mice.

PubMed

Franko, Andras; Kunze, Alexander; Böse, Marlen; von Kleist-Retzow, Jürgen-Christoph; Paulsson, Mats; Hartmann, Ursula; Wiesner, Rudolf J

2017-05-30

Mitochondria play a pivotal role in energy metabolism, but whether insulin signaling per se could regulate mitochondrial function has not been identified yet. To investigate whether mitochondrial function is regulated by insulin signaling, we analyzed muscle and liver of insulin receptor (IR) +/- -insulin receptor substrate-1 (IRS-1) +/- double heterozygous (IR-IRS1dh) mice, a well described model for insulin resistance. IR-IRS1dh mice were studied at the age of 6 and 12 months and glucose metabolism was determined by glucose and insulin tolerance tests. Mitochondrial enzyme activities, oxygen consumption, and membrane potential were assessed using spectrophotometric, respirometric, and proton motive force analysis, respectively. IR-IRS1dh mice showed elevated serum insulin levels. Hepatic mitochondrial oxygen consumption was reduced in IR-IRS1dh animals at 12 months of age. Furthermore, 6-month-old IR-IRS1dh mice demonstrated enhanced mitochondrial respiration in skeletal muscle, but a tendency of impaired glucose tolerance. On the other hand, 12-month-old IR-IRS1dh mice showed improved glucose tolerance, but normal muscle mitochondrial function. Our data revealed that deficiency in IR/IRS-1 resulted in normal or even elevated skeletal muscle, but impaired hepatic mitochondrial function, suggesting a direct cross-talk between insulin signaling and mitochondria in the liver.

The synthetic triterpenoid RTA dh404 (CDDO-dhTFEA) restores endothelial function impaired by reduced Nrf2 activity in chronic kidney disease.

PubMed

Aminzadeh, Mohammad A; Reisman, Scott A; Vaziri, Nosratola D; Shelkovnikov, Stan; Farzaneh, Seyed H; Khazaeli, Mahyar; Meyer, Colin J

2013-01-01

Chronic kidney disease (CKD) is associated with endothelial dysfunction and accelerated cardiovascular disease, which are largely driven by systemic oxidative stress and inflammation. Oxidative stress and inflammation in CKD are associated with and, in part, due to impaired activity of the cytoprotective transcription factor Nrf2. RTA dh404 is a synthetic oleanane triterpenoid compound which potently activates Nrf2 and inhibits the pro-inflammatory transcription factor NF-κB. This study was designed to test the effects of RTA dh404 on endothelial function, inflammation, and the Nrf2-mediated antioxidative system in the aorta of rats with CKD induced by 5/6 nephrectomy. Sham-operated rats served as controls. Subgroups of CKD rats were treated orally with RTA dh404 (2 mg/kg/day) or vehicle for 12 weeks. The aortic rings from untreated CKD rats exhibited a significant reduction in the acetylcholine-induced relaxation response which was restored by RTA dh404 administration. Impaired endothelial function in the untreated CKD rats was accompanied by significant reduction of Nrf2 activity (nuclear translocation) and expression of its cytoprotective target genes, as well as accumulation of nitrotyrosine and upregulation of NAD(P)H oxidases, 12-lipoxygenase, MCP-1, and angiotensin II receptors in the aorta. These abnormalities were ameliorated by RTA dh404 administration, as demonstrated by the full or partial restoration of the expression of all the above analytes to sham control levels. Collectively, the data demonstrate that endothelial dysfunction in rats with CKD induced by 5/6 nephrectomy is associated with impaired Nrf2 activity in arterial tissue, which can be reversed with long term administration of RTA dh404.

Interpreting the cross-sectional flow field in a river bank based on a genetic-algorithm two-dimensional heat-transport method (GA-VS2DH)

NASA Astrophysics Data System (ADS)

Su, Xiaoru; Shu, Longcang; Chen, Xunhong; Lu, Chengpeng; Wen, Zhonghui

2016-12-01

Interactions between surface waters and groundwater are of great significance for evaluating water resources and protecting ecosystem health. Heat as a tracer method is widely used in determination of the interactive exchange with high precision, low cost and great convenience. The flow in a river-bank cross-section occurs in vertical and lateral directions. In order to depict the flow path and its spatial distribution in bank areas, a genetic algorithm (GA) two-dimensional (2-D) heat-transport nested-loop method for variably saturated sediments, GA-VS2DH, was developed based on Microsoft Visual Basic 6.0. VS2DH was applied to model a 2-D bank-water flow field and GA was used to calibrate the model automatically by minimizing the difference between observed and simulated temperatures in bank areas. A hypothetical model was developed to assess the reliability of GA-VS2DH in inverse modeling in a river-bank system. Some benchmark tests were conducted to recognize the capability of GA-VS2DH. The results indicated that the simulated seepage velocity and parameters associated with GA-VS2DH were acceptable and reliable. Then GA-VS2DH was applied to two field sites in China with different sedimentary materials, to verify the reliability of the method. GA-VS2DH could be applied in interpreting the cross-sectional 2-D water flow field. The estimates of horizontal hydraulic conductivity at the Dawen River and Qinhuai River sites are 1.317 and 0.015 m/day, which correspond to sand and clay sediment in the two sites, respectively.

Role of dorsal hippocampus κ opioid receptors in contextual aversive memory consolidation in rats.

PubMed

Vanz, Felipe; Bicca, Maíra Assunção; Linartevichi, Vagner Fagnani; Giachero, Marcelo; Bertoglio, Leandro José; Monteiro de Lima, Thereza C

2018-06-01

The main κ opioid receptors (κORs) subtypes already described (κ 1 ORs and κ 2 ORs) are expressed in brain regions involved in aversive memory consolidation, including the dorsal hippocampus (DH). However, the role of DH κORs in consolidation of aversive memories with varied intensity and specificity is still uncertain. The present study aimed to investigate this question using pharmacological agents in rats subjected to a weak, moderate or strong contextual aversive conditioning (CAC) protocol. Antagonizing DH κORs with nor-binaltorphimine (nor-BNI), immediately after, but not 6 h later, a moderate CAC leads to intensified freezing behavior in the re-exposure to the paired context. Thus, indicating that DH κORs have an inhibitory role in the consolidation of an aversive memory. Increased DH κORs expression 1 h and 3 h after the moderate CAC was also observed. This up-regulation was absent in animals only exposed to the shock or to the context, indicating that this phenomenon requires a shock-context pairing to occur. Intra-DH nor-BNI infusion induced no changes following a weak CAC, but it was able to potentiate the expression of freezing behavior in novel and unpaired context after a strong CAC, indicating that DH κORs also modulate the consolidation of a more intense and generalized memory. Moreover, infusing the κ 2 ORs agonist GR 89696, but not the κ 1 ORs agonist U-69593, into the DH reduced the conditioned freezing expression. Nor-BNI pretreatment in a sub-effective dose prevented the κ 2 ORs agonist effects. Altogether, the present findings provide convergent evidence that κORs activation negatively modulates contextual aversive memory consolidation in rat dorsal hippocampus. Copyright © 2018. Published by Elsevier Ltd.

A human thyroid cancer cell line, DH-14-3, newly established from poorly differentiated thyroid carcinoma.

PubMed

Teshima, Jin; Doi, Hideyuki; Fujimori, Keisei; Watanabe, Michio; Nakajima, Noriaki; Nakano, Tomoyuki; Takahashi, Yoshio; Ohuchi, Noriaki; Satomi, Susumu

2013-06-01

Poorly differentiated thyroid carcinoma (PDTC) is a newly recognized histological type of malignant thyroid tumor, accounting for about 2 - 13% of all thyroid carcinomas. PDTC is considered as a morphologically and biologically intermediate stage between well-differentiated thyroid carcinoma and anaplastic thyroid carcinoma. PDTC preferentially manifests bone metastases. We here established a cell line from a resected tumor specimen from a 70-year-old male patient with PDTC who presented with multiple bone metastases. This new thyroid tumor cell line was designated as DH-14-3 and was subsequently grown in culture for several years. DH-14-3 cells express thyroglobulin in the cytoplasm and thyroid transcription factor-1 in the nuclei, both proteins of which are specific markers for the thyroid gland. Importantly, triiodothyronine (T3) was detected in the cultured medium of DH-14-3 cells, in which, however, thyroxine (T4) was undetectable. Moreover, DH-14-3 cells secreted interleukin-8, transforming growth factor-β1, vascular endothelial growth factor, matrix metalloproteinase-1 and parathyroid hormone-related protein, all of which may be responsible for the aggressiveness or bone metastasis of PDTC. Thus, the production of these proteins may reflect the metastatic potential of this cell line. DH-14-3 cells also express CXC chemokine receptor-4 and epidermal growth factor receptor, and carry a missense mutation in the p53 tumor suppressor gene. In fact, transplantation of DH-14-3 cells into the back of nude mice resulted in the formation of tumors, thereby confirming the capability of tumorigenesis. DH-14-3 cells may be useful for investigating the biological features of PDTC and will contribute to the therapeutic study of thyroid cancer.

Nebular dead zone effects on the D/H ratio in chondrites and comets

NASA Astrophysics Data System (ADS)

Ali-Dib, Mohamad; Martin, R. G.; Petit, J.-M.; Mousis, O.; Vernazza, P.; Lunine, J. I.

2015-11-01

Comets and chondrites show non-monotonic behaviour of their Deuterium to Hydrogen (D/H) ratio as a function of their formation location from the Sun. This is difficult to explain with a classical protoplanetary disk model that has a decreasing temperature structure with radius from the Sun.We want to understand if a protoplanetary disc with a dead zone, a region of zero or low turbulence, can explain the measured D/H values in comets and chondrites. We use time snapshots of a vertically layered disk model with turbulent surface layers and a dead zone at the midplane. The disc has a non-monotonic temperature structure due to increased heating from self-gravity in the outer parts of the dead zone. We couple this to a D/H ratio evolution model in order to quantify the effect of such thermal profiles on D/H enrichment in the nebula.We find that the local temperature peak in the disk can explain the diversity in the D/H ratios of different chondritic families. This disk temperature profile leads to a non-monotonic D/H enrichment evolution, allowing these families to acquire their different D/H values while forming in close proximity. The formation order we infer for these families is compatible with that inferred from their water abundances. However, we find that even for very young disks, the thermal profile reversal is too close to the Sun to be relevant for comets.[1] Ali-Dib, M., Martin, R. G., Petit, J.-M., Mousis, O., Vernazza, P., and Lunine, J. I. (2015, in press A&A). arXiv:1508.00263.

Consensus generation and variant detection by Celera Assembler.

PubMed

Denisov, Gennady; Walenz, Brian; Halpern, Aaron L; Miller, Jason; Axelrod, Nelson; Levy, Samuel; Sutton, Granger

2008-04-15

We present an algorithm to identify allelic variation given a Whole Genome Shotgun (WGS) assembly of haploid sequences, and to produce a set of haploid consensus sequences rather than a single consensus sequence. Existing WGS assemblers take a column-by-column approach to consensus generation, and produce a single consensus sequence which can be inconsistent with the underlying haploid alleles, and inconsistent with any of the aligned sequence reads. Our new algorithm uses a dynamic windowing approach. It detects alleles by simultaneously processing the portions of aligned reads spanning a region of sequence variation, assigns reads to their respective alleles, phases adjacent variant alleles and generates a consensus sequence corresponding to each confirmed allele. This algorithm was used to produce the first diploid genome sequence of an individual human. It can also be applied to assemblies of multiple diploid individuals and hybrid assemblies of multiple haploid organisms. Being applied to the individual human genome assembly, the new algorithm detects exactly two confirmed alleles and reports two consensus sequences in 98.98% of the total number 2,033311 detected regions of sequence variation. In 33,269 out of 460,373 detected regions of size >1 bp, it fixes the constructed errors of a mosaic haploid representation of a diploid locus as produced by the original Celera Assembler consensus algorithm. Using an optimized procedure calibrated against 1 506 344 known SNPs, it detects 438 814 new heterozygous SNPs with false positive rate 12%. The open source code is available at: http://wgs-assembler.cvs.sourceforge.net/wgs-assembler/

Split T-cell tolerance in herpes simplex virus-infected mice and its implication for anti-viral immunity.

PubMed Central

Nash, A A; Ashford, N P

1982-01-01

Mice simultaneously injected intravenously and subcutaneously with herpes simplex virus fail to adoptively transfer delayed hypersensitivity (DH) to syngeneic recipients. The transferred lymph node cells also failed to rapidly eliminate infectious herpes from the pinna, despite the presence of cytotoxic T cells in the transferred suspension. Both primary and secondary cytotoxic cell responses in the draining lymph node were unaffected by the inhibition of DH. The lymph nodes from DH tolerized mice also contain lymphocytes capable of undergoing a proliferative response in vitro to herpes antigens. In addition, a neutralizing antibody response with IgG antibodies against herpes are also present in DH tolerized mice. These data suggest a form of split T-cell tolerance in which only DH responses are directly compromised. The implication of these findings for the pathogenesis of herpes simplex virus is discussed. PMID:6279490

The evolutionary dynamics of haplodiploidy: Genome architecture and haploid viability.

PubMed

Blackmon, Heath; Hardy, Nate B; Ross, Laura

2015-11-01

Haplodiploid reproduction, in which males are haploid and females are diploid, is widespread among animals, yet we understand little about the forces responsible for its evolution. The current theory is that haplodiploidy has evolved through genetic conflicts, as it provides a transmission advantage to mothers. Male viability is thought to be a major limiting factor; diploid individuals tend to harbor many recessive lethal mutations. This theory predicts that the evolution of haplodiploidy is more likely in male heterogametic lineages with few chromosomes, as genes on the X chromosome are often expressed in a haploid environment, and the fewer the chromosome number, the greater the proportion of the total genome that is X-linked. We test this prediction with comparative phylogenetic analyses of mites, among which haplodiploidy has evolved repeatedly. We recover a negative correlation between chromosome number and haplodiploidy, find evidence that low chromosome number evolved prior to haplodiploidy, and that it is unlikely that diplodiploidy has reevolved from haplodiploid lineages of mites. These results are consistent with the predicted importance of haploid male viability. © 2015 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

Exact solutions for the selection-mutation equilibrium in the Crow-Kimura evolutionary model.

PubMed

Semenov, Yuri S; Novozhilov, Artem S

2015-08-01

We reformulate the eigenvalue problem for the selection-mutation equilibrium distribution in the case of a haploid asexually reproduced population in the form of an equation for an unknown probability generating function of this distribution. The special form of this equation in the infinite sequence limit allows us to obtain analytically the steady state distributions for a number of particular cases of the fitness landscape. The general approach is illustrated by examples; theoretical findings are compared with numerical calculations. Copyright © 2015. Published by Elsevier Inc.

Morphoagronomic characterization and genetic diversity of a common bean RIL mapping population derived from the cross Rudá x AND 277.

PubMed

Silva, L C; Batista, R O; Anjos, R S R; Souza, M H; Carneiro, P C S; Souza, T L P O; Barros, E G; Carneiro, J E S

2016-07-29

Recombinant inbred lines (RILs) are a valuable resource for building genetic linkage maps. The presence of genetic variability in the RILs is essential for detecting associations between molecular markers and loci controlling agronomic traits of interest. The main goal of this study was to quantify the genetic diversity of a common bean RIL population derived from a cross between Rudá (Mesoamerican gene pool) and AND 277 (Andean gene pool). This population was developed by the single seed descent method from 500 F2 plants until the F10 generation. Seven quantitative traits were evaluated in the field in 393 RILs, the parental lines, and five control cultivars. The plants were grown using a randomized block design with additional controls and three replicates. Significant differences were observed among the RILs for all evaluated traits (P < 0.01). A comparison of the RILs and parental lines showed significant differences (P < 0.01) for the number of days to flowering (DFL) and to harvest (DH), productivity (PROD) and mass of 100 beans (M100); however, there were no significant differences for plant architecture, degree of seed flatness, or seed shape. These results indicate the occurrence of additive x additive epistatic interactions for DFL, DH, PROD, and M100. The 393 RILs were shown to fall into 10 clusters using Tocher's method. This RIL population clearly contained genetic variability for the evaluated traits, and this variability will be crucial for future studies involving genetic mapping and quantitative trait locus identification and analysis.

Contribution of a selected fungal population to proteolysis on dry-cured ham.

PubMed

Martín, Alberto; Córdoba, Juan J; Núñez, Félix; Benito, María J; Asensio, Miguel A

2004-07-01

The proteolytic changes taking place in dry-cured hams lead to increases in free amino acids. Such free amino acids not only contribute to flavour, but also serve as precursors of volatile compounds. Several months of ripening time are required to allow the particular flavour to develop. The fungal population allowed to grow on the surface of some types of dry-cured could play a key role on proteolysis, as it has been shown for dry-cured sausages. The purpose of this work was to study the possible contribution of fungi to proteolysis in dry-cured ham. For this, a strain each of non-toxigenic Penicillium chrysogenum (Pg222) and Debaryomyces hansenii (Dh345), selected for their proteolytic activity on myofibrillar proteins, were inoculated as starter cultures. Changes in the high ionic strength-soluble proteins of an external muscle (adductor) revealed in only 6 months higher proteolysis in the inoculated hams when compared to non-inoculated control hams. Proteolytic strains among the wild fungal population on non-inoculated control hams prevented from obtaining similar differences at the end of processing. However, inoculation with Pg222 and Dh345 led to higher levels for most free amino acids at the external muscle in fully dry-cured hams. In addition, the concentration for some of the more polar free amino acids (i.e. Asp, Glu, Ser and Gln) in inoculated hams was higher at external than at internal (biceps femoris) muscles. These promising results deserve further studies to know the impact of a selected fungal population on the volatile compounds and sensory properties of dry-cured ham.

USAF Dehumidification Efforts for Corrosion Control

DTIC Science & Technology

2011-08-16

Stored AGE Renewable energy powers dehumidification equipment (DH) DH maintains dry air in storage booths, protecting AGE equipment from...lighting also powered by renewable energy 11 CHP Shelters • Used to prevent corrosion on outer skin • Being developed for the F-22 at...DH can be Sheltered or Unsheltered • Air Dehydration Units - Uses a self rejuvenating desiccant wheel dehumidifier - Closed or open loop

Allergy to dexchlorpheniramine. Study of a case.

PubMed

Cáceres Calle, O; Fernández-Benítez, M

2004-01-01

Dexchlorpheniramine (DH) is a classical or first generation antihistamine belonging to the ethanolamine group. Adverse effects related to these antihistamines are frequent, but the hypersensitivity reactions described in the literature since 1940 are exceptional. We report the case of a 32-year-old woman who experienced two episodes of akathisia secondary to intravenous (i.v.) dexchlorpheniramine administration for a possible hypersensitivity reaction to local anesthetics. Allergological study consisted of the following tests: skin prick tests with routine allergens, with a negative result; skin prick and intradermal tests with local anesthetics and DH, with a positive result to DH in the intradermal skin test (+ +); serum specific IgE, which was within normal levels; histamine release test with DH with a negative result, and the basophil activation test (BAT) with local anesthetics and DH, which was positive for DH and weakly positive to Lidocaine. BAT is proving to be a highly useful tool in the field of drug allergy, with a higher sensitivity and specificity than other in vitro tests. Because it avoids the need for provocation tests, this is especially important in drug-induced allergic reactions in which in vivo tests are repeatedly negative despite a clear clinical history.

A high deuterium abundance at redshift z = 0.7.

PubMed

Webb, J K; Carswell, R F; Lanzetta, K M; Ferlet, R; Lemoine, M; Vidal-Madjar, A; Bowen, D V

1997-07-17

Of the light elements, the primordial abundance of deuterium relative to hydrogen, (D/H)p, provides the most sensitive diagnostic for the cosmological mass density parameter, omegaB. Recent high-redshift D/H measurements are highly discrepant, although this may reflect observational uncertainties. The larger primordial D/H values imply a low omegaB (requiring the Universe to be dominated by non-baryonic matter), and cause problems for galactic chemical evolution models, which have difficulty in reproducing the steep decline in D/H to the present-day values. Conversely, the lower D/H values measured at high redshift imply an omegaB greater than that derived from 7Li and 4He abundance measurements, and may require a deuterium-abundance evolution that is too low to easily explain. Here we report the first measurement of D/H at intermediate redshift (z = 0.7010), in a gas cloud selected to minimize observational uncertainties. Our analysis yields a value of D/H ((2.0 +/- 0.5) x 10[-4]) which is at the upper end of the range of values measured at high redshifts. This finding, together with other independent observations, suggests that there may be inhomogeneity in (D/H)p of at least a factor of ten.

Deuterohemin-Peptide Enzyme Mimic-Embedded Metal-Organic Frameworks through Biomimetic Mineralization with Efficient ATRP Catalytic Activity.

PubMed

Jiang, Wei; Wang, Xinghuo; Chen, Jiawen; Liu, Ying; Han, Haobo; Ding, Yi; Li, Quanshun; Tang, Jun

2017-08-16

An enzyme mimic harboring iron porphyrin (DhHP-6) embedded in zeolite imidazolate framework-8 (ZIF-8) was constructed through a biomimetic mineralization approach to obtain composite DhHP-6@ZIF-8. The composite was then used as a catalyst in the atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA 500 ) in which poly(PEGMA 500 ) could be synthesized with monomer conversion of 76.1% and M n of 45 900 g/mol, stronger than that obtained when using free DhHP-6 as a catalyst. More importantly, it could efficiently overcome the drawbacks of free DhHP-6 and achieve the easy separation of DhHP-6 from the catalytic system and the elimination of iron residues in the synthesized polymer. In addition, it exhibited an enhanced recyclability with monomer conversion of 75.7% after five cycles and favorable stability during the ATRP reaction with <3.0% of DhHP-6 release within 100 h. Thus, the enzyme mimic-ZIF-8 composite developed through biomimetic mineralization can be potentially used as an effective catalyst for preparing well-defined polymers with biomedical applications.

The NRF2 activator DH404 attenuates adverse ventricular remodeling post-myocardial infarction by modifying redox signalling.

PubMed

Bubb, Kristen J; Kok, Cindy; Tang, Owen; Rasko, Nathalie B; Birgisdottir, Asa B; Hansen, Thomas; Ritchie, Rebecca; Bhindi, Ravinay; Reisman, Scott A; Meyer, Colin; Ward, Keith; Karimi Galougahi, Keyvan; Figtree, Gemma A

2017-07-01

The novel synthetic triterpenoid, bardoxolone methyl, has the ability to upregulate cytoprotective proteins via induction of the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway. This makes it a promising therapeutic agent in disease states characterized by dysregulated oxidative signalling. We have examined the effect of a Nrf2 activator, dihydro-CDDO-trifluoroethyl amide (DH404), a derivative of bardoxolone methyl, on post-infarct cardiac remodeling in rats. DH404, administered from day 2 post myocardial infarction (MI: 30min transient ischemia followed by reperfusion) resulted in almost complete protection against adverse ventricular remodeling as assessed at day 28 (left ventricular end-systolic area: sham 0.14±0.01cm 2 , MI vehicle 0.29±0.04cm 2 vs. MI DH404 0.18±0.02cm 2 , P<0.05); infarct size (21.3±3.4% MI vehicle vs. 10.9±2.3% MI DH404, P<0.05) with associated benefits on systolic function (fractional shortening: sham 71.9±2.6%, MI vehicle 36.2±1.9% vs. MI DH404 58.6±4.0%, P<0.05). These structural and functional benefits were associated with lower myocardial expression of atrial natriuretic peptide (ANP, P<0.01 vs. MI vehicle), and decreased fibronectin (P<0.01 vs. MI vehicle) in DH404-treated MI rats at 28 days. MI increased glutathionylation of endothelial nitric oxide synthase (eNOS) in vitro - a molecular switch that uncouples the enzyme, increasing superoxide production and decreasing nitric oxide (NO) bioavailability. MI-induced eNOS glutathionylation was substantially ameliorated by DH404. An associated increase in glutaredoxin 1 (Grx1) co-immunoprecipitation with eNOS without a change in expression was mechanistically intriguing. Indeed, in parallel in vitro experiments, silencing of Grx1 abolished the protective effect of DH404 against Angiotensin II-induced eNOS uncoupling. The bardoxolone derivative DH404 significantly attenuated cardiac remodeling post MI, at least in part, by re-coupling of eNOS and increasing the functional interaction of Grx1 with eNOS. This agent may have clinical benefits protecting against post MI cardiomyopathy. Copyright © 2017. Published by Elsevier Inc.

Organization and mobility of CD11b/CD18 and targeting of superoxide on the surface of degranulated human neutrophils.

PubMed

Mukherjee, G; Rasmusson, B; Linner, J G; Quinn, M T; Parkos, C A; Magnusson, K E; Jesaitis, A J

1998-09-01

A monoclonal IgM, specifically recognizing both CD11b and CD18 of human neutrophils, was used to examine the organization and mobility of CD11b/CD18 in the plasma membrane of human neutrophils degranulated by dihydrocytochalasin B (dhCB) treatment and fMet-Leu-Phe (fMLF) stimulation. Subcellular fractionation analysis of untreated or dhCB-treated control neutrophils indicated that 20% of CD11b/CD18 cosedimented with plasma membrane and the remainder with specific granules. In contrast, fMLF stimulation of dhCB-treated cells caused a major reorganization of CD11b/CD18, in which 60-70% of CD11b/CD18 sedimented in dense plasma membrane fractions that were also enriched in superoxide-generating NADPH oxidase activity. Similarly pretreated neutrophils were fixed, immunogold labeled, and examined by scanning electron microscopy. Immunogold particles were distributed uniformly over the symmetrically ruffled surface of unstimulated neutrophils. On dhCB-treated cells, immunogold was mostly uniformly distributed on a smooth membrane with a small percentage of particles lining up into linear arrays. After fMLF + dhCB stimulation, CD11b/CD18 gold label was more abundant on the cell surface and formed large aggregates on polarized membrane protrusions. However, when cells were adhered to an albumin-coated quartz surface and stimulated with fMLF in the presence of dhCB, immunogold was excluded on the articulated and rounded cell body but concentrated on the periphery of adherent lamellae. Fluorescence photobleaching recovery indicated that in unstimulated cells 38 +/- 3% of CD11b/CD18 was mobile (R) with a diffusion constant D of 3.1 +/- 0.3 x 10(-10) cm2/s. Treatment with dhCB raised R and D 24 and 74%, respectively. Stimulation using 1 microM fMLF with dhCB lowered D and R to near control levels. Since NADPH oxidase and CD11b/CD18 cosediment in high-density plasma membrane domains after fMLF + dhCB stimulation, we speculate that a stimulus-induced reorganization of CD11b/CD18 and NADPH oxidase to common membrane domains may occur in fMLF + dhCB-degranulated neutrophils. Copyright 1998 Academic Press.

Transpressional deformation style and AMS fabrics adjacent to the southernmost segment of the San Andreas fault, Durmid Hill, CA

NASA Astrophysics Data System (ADS)

French, M.; Wojtal, S. F.; Housen, B.

2006-12-01

In the Salton Trough, the trace of the San Andreas Fault (SAF) ends where it intersects the NNW-trending Brawley seismic zone at Durmid Hill (DH). The topographic relief of DH is a product of faulting and folding of Pleistocene Borrego Formation strata (Babcock, 1974). Burgmann's (1991) detailed mapping and analysis of the western part of DH showed that the folds and faults accommodate transpression. Key to Burgmann's work was the recognition that the ~2m thick Bishop Ash, a prominent marker horizon, has been elongated parallel to the hinges of folds and boudinaged. We are mapping in detail the eastern portion of DH, nearer to the trace of the SAF. Folds in the eastern part of DH are tighter and thrust faulting is more prominent, consistent with greater shortening magnitude oblique to the SAF. Boudinage of the ash layer again indicates elongation parallel to fold hinges and subparallel to the SAF. The Bishop Ash locally is <1m thick along fold limbs in eastern DH, suggesting that significant continuous deformation accompanied the development of map-scale features. We measured anisotropy of magnetic susceptibility (AMS) fabrics in the Bishop Ash in order to assess continuous deformation in the Ash at DH. Because the Bishop Ash at DH is altered, consisting mainly of silica glass and clay minerals, samples from DH have significantly lower magnetic susceptibilities than Bishop Ash samples from elsewhere in the Salton Trough. With such low susceptibilities, there is significant scatter in the orientation of magnetic foliation and lineation in our samples. Still, in some Bishop samples within 1 km of the SAF, magnetic foliation is consistent with fold-related flattening. Magnetic lineation in these samples is consistently sub-parallel to fold hinges, parallel to the elongation direction inferred from boudinage. Even close to the trace of the SAF, this correlation breaks down in map-scale zones where fold hinge lines change attitude, fold shapes change, and the distribution and orientations of fractures and veins changes. These zones of structural complication separate broader regions of more uniform deformation patterns. Together, the geometry of structures and AMS fabrics suggest that deformation in eastern DH occurs by the distortion and reorientation of more or less coherent blocks separated by narrow zones where structural elements change orientation.

Isolation and Characterization of Isogenic Pairs of Domed Hemolytic and Flat Nonhemolytic Colony Types of Bordetella pertussis

PubMed Central

Peppler, Mark S.

1982-01-01

Four different serotype strains of Bordetella pertussis, 3779BL2S4, Tohama I, 353/Z, and 2753, were plated on Bordet-Gengou agar, where they grew as domed, hemolytic (D+H+) wild-type colonies. Cloned D+H+ colony types of all four strains were passed onto modified Stainer-Scholte medium solidified with 1% Noble Agar. Colonies were selected from Stainer-Scholte agar, and these subsequently grew as flat, nonhemolytic (D−H−) colonies when transferred back onto Bordet-Gengou agar. The frequency of D−H− organisms within a population of cloned D+H+ was determined to be between 5 × 10−5 and 5 × 10−6. The D−H− colony types maintained their flat, nonhemolytic characteristics for over 80 single-colony passages on Bordet-Gengou agar. The isogenic pairs of D+H+ and D−H− colony types from the four strains were compared for hemagglutination titer, lymphocytosis-promoting activity, adenylate cyclase activity, and presence of agglutinogens by agglutination. In all cases the D−H− colony types showed reduced activities or amounts of antigen compared with their D+H+ parents. Freely diffusible antigens were markedly different between the two phenotypes as noted by double diffusion of antisera added to plates on which colonies of the variants were growing. Antigens solubilized from the two colony types by Triton X-100 were also markedly different as judged by radial immunodiffusion with antifimbrial hemagglutinin, antilymphocytosis-promoting factor, and anti-353/Z adsorbed with autoclaved 353/Z. In addition, autoradiographs of 125I-surface-labeled whole cells separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed unique banding patterns for each colony type. Since all organisms, regardless of colony type, were grown on Bordet-Gengou agar, the differences reported could not be due to medium composition. Differences between phenotypes were also independent of passage number on Bordet-Gengou agar. By analogy to previous studies, the D−H− organisms appear to fulfill the criteria for phase III or phase IV in the system of Leslie and Gardner (P. H. Leslie and A. D. Gardner, J. Hyg. 31:423-434, 1931) or phase III in the system of Kasuga et al. (T. Kasuga, Y. Nakase, K. Ukishima, and K. Takatsu, Kitasato Arch. Exp. Med. 26:121-134, 1954). Images PMID:6279517

Separate and combined effects of dehydration and thirst sensation on exercise performance in the heat.

PubMed

Cheung, S S; McGarr, G W; Mallette, M M; Wallace, P J; Watson, C L; Kim, I M; Greenway, M J

2015-06-01

Using intravenous infusion, we separated the physiologic consequences of 3% body mass dehydration from the conscious awareness of fluid replacement on time trial (TT) performance in the heat. Eleven trained cyclists performed 90 min of steady-state (50% V ˙ O 2 peak ) cycling followed by a self-paced 20-km TT in a hot-dry (35 °C, 10% relative humidity, wind speed 3.0 m/s) environment while euhydrated-not thirsty (EU-NT), euhydrated-thirsty (EU-T), dehydrated-not thirsty (DH-NT), or dehydrated-thirsty (DH-T). Thirst was manipulated by providing (NT) or withholding (T) ad libitum 35 °C water oral rinse. Distinct hydration states existed, with 0.4 ± 0.5% dehydration following the 20-km TT (EU) compared with 3.2 ± 0.6% in DH (P < 0.001). Greater perceived thirst existed in T (7 ± 2 on a 1-9 scale) than NT (4 ± 2, P < 0.001) after the TT. No significant differences in power output existed during the TT between hydration (EU 202.9 ± 36.5 W vs DH 207.0 ± 35.9 W, P = 0.362) and thirst conditions (NT 203.3 ± 35.6 W vs T 206.6 ± 36.8 W, P = 0.548), nor were there differences in completion time (P = 0.832) or pacing profile (P = 0.690). Within the range of up to 3% body mass loss, neither the physiologic effects from lowered hydration status nor the perception of thirst, separately or combined, affected sustained submaximal exercise performance in the heat for a healthy and fit population. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A GREAT search for Deuterium in Comets

NASA Astrophysics Data System (ADS)

Mumma, Michael

2012-10-01

Comets are understood to be the most pristine bodies in the Solar System. Their compositions reflect the chemical state of materials at the very earliest evolutionary stages of the protosolar nebula and, as such, they provide detailed insight into the physical and chemical processes operating in planet-forming disks. Isotopic fractionation ratios of the molecular ices in the nucleus are regarded as signatures of formation processes. These ratios provide unique information on the natal heritage of those ices, and can also test the proposal that Earth's water and other volatiles were delivered by cometary bombardment. Measurement of deuterium fractionation ratios is thus a major goal in contemporary cometary science and the D/H ratio of water - the dominant volatile in comets - holds great promise for testing the formation history of cometary matter. The D/H ratio in cometary water has been measured in only seven comets. Six were from the Oort Cloud reservoir and the D/H ratio was about twice that of the Earth's oceans. However, the recent Herschel measurement of HDO/H2O in 103P/Hartley-2 (the first from the Kuiper Belt) was consistent with exogenous delivery of Earth's water by comets. Outstanding questions remain: are cometary HDO/H2O ratios consistent with current theories of nebular chemical evolution or with an interstellar origin? Does the HDO/H2O ratio vary substantially among comet populations? Hartley-2 is the only Kuiper Belt comet with measured HDO/H2O, are there comets with similar ratios in the Oort cloud? These questions can only be addressed by measuring HDO/H2O ratios in many more suitable bright comets. We therefore propose to measure the D/H ratio in water in a suitable target-of-opportunity comet by performing observations of HDO and OH with the GREAT spectrometer on SOFIA. A multi-wavelength, ground-based observing campaign will also be conducted in support of the airborne observations.

A GREAT search for Deuterium in Comets

NASA Astrophysics Data System (ADS)

Mumma, Michael

2013-10-01

Comets are understood to be the most pristine bodies in the Solar System. Their compositions reflect the chemical state of materials at the very earliest evolutionary stages of the protosolar nebula and, as such, they provide detailed insight into the physical and chemical processes operating in planet-forming disks. Isotopic fractionation ratios of the molecular ices in the nucleus are regarded as signatures of formation processes. These ratios provide unique information on the natal heritage of those ices, and can also test the proposal that Earth's water and other volatiles were delivered by cometary bombardment. Measurement of deuterium fractionation ratios is thus a major goal in contemporary cometary science and the D/H ratio of water - the dominant volatile in comets - holds great promise for testing the formation history of cometary matter. The D/H ratio in cometary water has been measured in only eight comets. Seven were from the Oort Cloud reservoir and the D/H ratio was about twice that of the Earth's oceans. However, the recent Herschel measurement of HDO/H2O in 103P/Hartley-2 (the first from the Kuiper Belt) was consistent with exogenous delivery of Earth's water by comets. Outstanding questions remain: are cometary HDO/H2O ratios consistent with current theories of nebular chemical evolution or with an interstellar origin? Does the HDO/H2O ratio vary substantially among comet populations? Hartley-2 is the only Kuiper Belt comet with measured HDO/H2O, are there comets with similar ratios in the Oort cloud? These questions can only be addressed by measuring HDO/H2O ratios in many more suitable bright comets. We therefore propose to measure the D/H ratio in water in a suitable target-of-opportunity comet by performing observations of HDO and OH with the GREAT spectrometer on SOFIA. A multi-wavelength, ground-based observing campaign will also be conducted in support of the airborne observations.

Integration of Decentralized Thermal Storages Within District Heating (DH) Networks

NASA Astrophysics Data System (ADS)

Schuchardt, Georg K.

2016-12-01

Thermal Storages and Thermal Accumulators are an important component within District Heating (DH) systems, adding flexibility and offering additional business opportunities for these systems. Furthermore, these components have a major impact on the energy and exergy efficiency as well as the heat losses of the heat distribution system. Especially the integration of Thermal Storages within ill-conditioned parts of the overall DH system enhances the efficiency of the heat distribution. Regarding an illustrative and simplified example for a DH system, the interactions of different heat storage concepts (centralized and decentralized) and the heat losses, energy and exergy efficiencies will be examined by considering the thermal state of the heat distribution network.

Oilseed rape seeds with ablated defence cells of the glucosinolate–myrosinase system. Production and characteristics of double haploid MINELESS plants of Brassica napus L.

PubMed Central

Ahuja, Ishita; Borgen, Birgit Hafeld; Hansen, Magnor; Honne, Bjørn Ivar; Müller, Caroline; Rohloff, Jens; Rossiter, John Trevor; Bones, Atle Magnar

2011-01-01

Oilseed rape and other crop plants of the family Brassicaceae contain a unique defence system known as the glucosinolate–myrosinase system or the ‘mustard oil bomb’. The ‘mustard oil bomb’ which includes myrosinase and glucosinolates is triggered by abiotic and biotic stress, resulting in the formation of toxic products such as nitriles and isothiocyanates. Myrosinase is present in specialist cells known as ‘myrosin cells’ and can also be known as toxic mines. The myrosin cell idioblasts of Brassica napus were genetically reprogrammed to undergo controlled cell death (ablation) during seed development. These myrosin cell-free plants have been named MINELESS as they lack toxic mines. This has led to the production of oilseed rape with a significant reduction both in myrosinase levels and in the hydrolysis of glucosinolates. Even though the myrosinase activity in MINELESS was very low compared with the wild type, variation was observed. This variability was overcome by producing homozygous seeds. A microspore culture technique involving non-fertile haploid MINELESS plants was developed and these plants were treated with colchicine to produce double haploid MINELESS plants with full fertility. Double haploid MINELESS plants had significantly reduced myrosinase levels and glucosinolate hydrolysis products. Wild-type and MINELESS plants exhibited significant differences in growth parameters such as plant height, leaf traits, matter accumulation, and yield parameters. The growth and developmental pattern of MINELESS plants was relatively slow compared with the wild type. The characteristics of the pure double haploid MINELESS plant are described and its importance for future biochemical, agricultural, dietary, functional genomics, and plant defence studies is discussed. PMID:21778185

Fatigue Lives of Specimens Representing Critical Locations in Mirage III Spars under Australian and Swiss Test Spectra,

DTIC Science & Technology

1985-02-01

TF16 103 TFI 1 143 TV21 183 TFI I 24 FI-7 64 T-21 104 THI7 144 TF4 184 TFI7 25 T1I 65 T122 105 T-18 145 TFI5 185 TF24 26 TF13 66 Tt-I9 106 T1:5 [ 146...4.990 9GB I)H 2 2 4 6 7.990 161E-2 DH -2 I S.046 N.910 0.079 131) PH 2.2 4 6 10.990 126 I)lf 20 II 12.564 7EB D H 1.8 4-6 12.643 9BB DH I x 4-6 2.703...13.990 0-075 IOJA DH IŜ 46 6 7,064 7F D H 1-4 4.6 29,185 12 D DH 1-4 4.6 52.292 43,230 0148 I IJB DH i 4 4.6 52.953 Swiss sequeLce 19E SH 2Ŗ 9.3

Influence of hydrolysis behaviour and microfluidisation on the functionality and structural properties of collagen hydrolysates.

PubMed

Zhang, Yehui; Zhang, Yousheng; Liu, Xueming; Huang, Lihua; Chen, Zhiyi; Cheng, Jingrong

2017-07-15

The functionality and structural properties of pig skin hydrolysates with different degrees of hydrolysis (DH, 10% and 20%) and microfluidisation (120MPa), prepared by pepsin and Alcalase® have been investigated in this study. Extensive hydrolysis can significantly improve the absolute value of the zeta potential and surface hydrophobicity. The particle distribution of hydrolysates decreased with increasing DH. The numbers of free sulfhydryl (SH) and disulfide bonds (SS) were significantly increased with increasing DH (p<0.05). Hydrolysates with a lower DH showed a better emulsifying property than those with a higher DH. Microfluidisation led to the transformation of structural and interfacial properties of the hydrolysates and increased the value of the zeta potential, S 0 , and gel strength. Microfluidisation results in limited breakage of chemical bonds, the number of SS and SH bonds unchanged in the treatment. These results reflect the functionality and structural properties of collagen-rich pig skin hydrolysates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Crucial roles of NGF in dorsal horn plasticity in partially deafferentated cats.

PubMed

Liu, Jia; Chen, Shan-Shan; Dan, Qi-Qin; Rong, Rong; Zhou, Xue; Zhang, Lian-Feng; Wang, Ting-Hua

2011-04-01

Though exogenous nerve growth factor (NGF) has been implicated in spinal cord plasticity, whether endogenous NGF plays a crucial role has not been established in vivo. This study investigated first the role of endogenous NGF in spinal dorsal horn (DH) plasticity following removal of L1-L5 and L7-S2 dorsal root ganglions (DRGs) in cats. Co-culture of chick embryo DRG with DH condition media, protein band fishing by cells as well as western blot showed that NGF could promote neurite growth in vitro. Immunohistochemistry and in situ hybridization technique revealed an increase in the NGF and NGF mRNA immunoreactive cells in the DH after partial deafferentation. Lastly, after blocking with NGF antibody, choleragen subunit B horseradish peroxidase (CB-HRP) tracing showed a reduction in the neuronal sprouting observed in the DH. Our results demonstrated that in the cat, endogenous NGF plays a crucial role in DH plasticity after partial deafferentation.

Fluid shifts during thermal stress with and without fluid replacement

NASA Technical Reports Server (NTRS)

Myhre, L. G.; Robinson, S.

1977-01-01

Six unacclimatized men rested for 4 hr in a hot, dry environment without fluid replacement (DH). Another group of six men were exposed to the same thermal stress, replacing evaporative fluid loss with warm 0.1% NaCl solution (FRP). Total grams of circulating hemoglobin, determined by CO immediately prior to and again during the last minutes of heat exposure, increased an insignificant 1.6 and 1.3% during DH and FRP, respectively. With DH, body weight loss of 2.6% was accompanied by a 7.8% reduction in calculated plasma volume (PV). Even when body weight was maintained (FRP), PV decreased 2.9% during the heat exposure. Total circulating serum protein did not change as a result of the heat stress with either DH or FRP. In a test-retest series of experiments on four men, DH was not detrimental to sweat rate. It is shown that hemodilution is not a general response to acute heat exposure. The disproportionately large reduction in PV during thermal dehydration is confirmed.

Inhibitors of dihydroceramide desaturase 1: Therapeutic agents and pharmacological tools to decipher the role of dihydroceramides in cell biology.

PubMed

Casasampere, Mireia; Ordoñez, Yadira F; Pou, Ana; Casas, Josefina

2016-05-01

Dihydroceramide desaturase (Des1) is the last enzyme in the de novo synthesis of ceramides (Cer). It catalyzes the insertion of a double bond into dihydroceramides (dhCer) to convert them to Cer, both of which are further metabolized to more complex (dihydro) sphingolipids. For many years dhCer have received poor attention, mainly due to their supposed lack of biological activity. It was not until about ten years ago that the concept that dhCer might have regulatory roles in biology emerged for the first time. Since then, multiple publications have established that dhCer are implicated in a wide spectrum of biological processes. Physiological and pathophysiological functions of dhCer have been recently reviewed. In this review we will focus on the biochemical features of Des1 and on its inhibition by different compounds with presumably different modes of action. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Bitterness in sodium caseinate hydrolysates: role of enzyme preparation and degree of hydrolysis.

PubMed

O'Sullivan, Dara; Nongonierma, Alice B; FitzGerald, Richard J

2017-10-01

Enzymatic hydrolysis of sodium caseinate (NaCas) may lead to the development of bitterness. Careful selection of hydrolysis conditions (i.e. enzyme preparation and duration) yielding different degrees of hydrolysis (DH) may aid in the development of low bitterness. Eighteen NaCas hydrolysates were generated with four enzyme preparations (Alcalase 2.4L, Prolyve 1000, FlavorPro Whey and pepsin) to different DH values. Hydrolysate bitterness score, assessed using a trained panel (ten assessors), generally increased at higher DH values for Alcalase, Prolyve and pepsin hydrolysates. However, all FlavorPro Whey hydrolysates (DH 0.38-10.62%) displayed low bitterness score values (<26.0%) comparable to that of intact NaCas (13.8 ± 2.0%, P > 0.05). Enzyme preparation and DH affect the bitterness of NaCas hydrolysates. The results are relevant for the generation of NaCas hydrolysates with reduced bitterness. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Recommendations of the DNA Commission of the International Society for Forensic Genetics (ISFG) on quality control of autosomal Short Tandem Repeat allele frequency databasing (STRidER).

PubMed

Bodner, Martin; Bastisch, Ingo; Butler, John M; Fimmers, Rolf; Gill, Peter; Gusmão, Leonor; Morling, Niels; Phillips, Christopher; Prinz, Mechthild; Schneider, Peter M; Parson, Walther

2016-09-01

The statistical evaluation of autosomal Short Tandem Repeat (STR) genotypes is based on allele frequencies. These are empirically determined from sets of randomly selected human samples, compiled into STR databases that have been established in the course of population genetic studies. There is currently no agreed procedure of performing quality control of STR allele frequency databases, and the reliability and accuracy of the data are largely based on the responsibility of the individual contributing research groups. It has been demonstrated with databases of haploid markers (EMPOP for mitochondrial mtDNA, and YHRD for Y-chromosomal loci) that centralized quality control and data curation is essential to minimize error. The concepts employed for quality control involve software-aided likelihood-of-genotype, phylogenetic, and population genetic checks that allow the researchers to compare novel data to established datasets and, thus, maintain the high quality required in forensic genetics. Here, we present STRidER (http://strider.online), a publicly available, centrally curated online allele frequency database and quality control platform for autosomal STRs. STRidER expands on the previously established ENFSI DNA WG STRbASE and applies standard concepts established for haploid and autosomal markers as well as novel tools to reduce error and increase the quality of autosomal STR data. The platform constitutes a significant improvement and innovation for the scientific community, offering autosomal STR data quality control and reliable STR genotype estimates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The discrete Laplace exponential family and estimation of Y-STR haplotype frequencies.

PubMed

Andersen, Mikkel Meyer; Eriksen, Poul Svante; Morling, Niels

2013-07-21

Estimating haplotype frequencies is important in e.g. forensic genetics, where the frequencies are needed to calculate the likelihood ratio for the evidential weight of a DNA profile found at a crime scene. Estimation is naturally based on a population model, motivating the investigation of the Fisher-Wright model of evolution for haploid lineage DNA markers. An exponential family (a class of probability distributions that is well understood in probability theory such that inference is easily made by using existing software) called the 'discrete Laplace distribution' is described. We illustrate how well the discrete Laplace distribution approximates a more complicated distribution that arises by investigating the well-known population genetic Fisher-Wright model of evolution by a single-step mutation process. It was shown how the discrete Laplace distribution can be used to estimate haplotype frequencies for haploid lineage DNA markers (such as Y-chromosomal short tandem repeats), which in turn can be used to assess the evidential weight of a DNA profile found at a crime scene. This was done by making inference in a mixture of multivariate, marginally independent, discrete Laplace distributions using the EM algorithm to estimate the probabilities of membership of a set of unobserved subpopulations. The discrete Laplace distribution can be used to estimate haplotype frequencies with lower prediction error than other existing estimators. Furthermore, the calculations could be performed on a normal computer. This method was implemented in the freely available open source software R that is supported on Linux, MacOS and MS Windows. Copyright © 2013 Elsevier Ltd. All rights reserved.

The resurgence of haploids in higher plants.

PubMed

Forster, Brian P; Heberle-Bors, Erwin; Kasha, Ken J; Touraev, Alisher

2007-08-01

The life cycle of plants proceeds via alternating generations of sporophytes and gametophytes. The dominant and most obvious life form of higher plants is the free-living sporophyte. The sporophyte is the product of fertilization of male and female gametes and contains a set of chromosomes from each parent; its genomic constitution is 2n. Chromosome reduction at meiosis means cells of the gametophytes carry half the sporophytic complement of chromosomes (n). Plant haploid research began with the discovery that sporophytes can be produced in higher plants carrying the gametic chromosome number (n instead of 2n) and that their chromosome number can subsequently be doubled up by colchicine treatment. Recent technological innovations, greater understanding of underlying control mechanisms and an expansion of end-user applications has brought about a resurgence of interest in haploids in higher plants.

Anther Culture in Eggplant (Solanum melongena L.).

PubMed

Rotino, Giuseppe Leonardo

2016-01-01

The technique of in vitro anther culture is the most favorite to incite the production of plants from microspore through direct embryogenesis or regeneration from callus. Anther culture has been employed since 1980s in eggplant to obtain double-haploid plants from microspore derived embryos. From that time it has been refined and widely applied both at commercial level for a fast generation double-haploid parental lines of F1 hybrids, as well as for experimental studies as the complete homozygosis of the microspore-derived plants make more simply the genetic analysis. In this chapter, a step-by-step procedure is reported, taking into consideration all the aspects of the technique, including the growth condition of the anther donor plant, the in vitro regeneration of the androgenetic plantlets, their ploidy analysis, and the colchicine treatment to double the chromosome number of the haploids.

Aircraft Accident Investigation at ARL: The First 50 Years

DTIC Science & Technology

1993-03-01

monoplane with vee strut bracing. Designed by De Havillands as the DH . 80A, it proved highly successful; two hundred and sixty were built in the UK...3 4. THE PUSS MOTH ACCIDENTS ............................................................ 5 5. THE DH .86 ACCIDENTS...Melbourne and just as the royal procession was turning from St Kilda Road into the grounds of Government House, two DH .9 aircraft of the RAAF flypast collided

Surface plasmon-enhanced dual-band infrared absorber for {{VO}}_{{\\boldsymbol{x}}}-based microbolometer application

NASA Astrophysics Data System (ADS)

Li, Qi; Yu, Bing-qiang; Li, Zhao-feng; Wang, Xiao-feng; Zhang, Zi-chen; Pan, Ling-feng

2017-08-01

Not Available Project supported by the One Hundred Talents Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China (Grant Nos. 61376083 and 61307077), the China Postdoctoral Science Foundation (Grant Nos. 2013M530613 and 2015T80080), and the Guangxi Key Laboratory of Precision Navigation Technology and Application (Grant Nos. DH201505, DH201510, and DH201511).

SN 2013dh in NGC 5936 is probably a type Iax supernova

NASA Astrophysics Data System (ADS)

Jha, Saurabh W.; McCully, Curtis; Foley, Ryan J.; Cenko, S. Bradley; Zheng, WeiKang; Clubb, Kelsey I.; Shivvers, Isaac; Filippenko, Alexei V.; Tucker, Brad E.; Garnavich, Peter M.

2013-06-01

Further to CBET 3561 (Kumar et al. 2013; Cenko et al. 2013), we have analyzed spectra of SN 2013dh obtained on June 14.3 and June 17.3 UT with the Shane 3-m reflector (+ Kast spectrograph) at Lick Observatory. The observations continue to show that SN 2013dh has a blue continuum with relatively narrow (FWHM approximately 3000 km/s) Fe III absorption.

Using DSLR cameras in digital holography

NASA Astrophysics Data System (ADS)

Hincapié-Zuluaga, Diego; Herrera-Ramírez, Jorge; García-Sucerquia, Jorge

2017-08-01

In Digital Holography (DH), the size of the bidimensional image sensor to record the digital hologram, plays a key role on the performance of this imaging technique; the larger the size of the camera sensor, the better the quality of the final reconstructed image. Scientific cameras with large formats are offered in the market, but their cost and availability limit their use as a first option when implementing DH. Nowadays, DSLR cameras provide an easy-access alternative that is worthwhile to be explored. The DSLR cameras are a wide, commercial, and available option that in comparison with traditional scientific cameras, offer a much lower cost per effective pixel over a large sensing area. However, in the DSLR cameras, with their RGB pixel distribution, the sampling of information is different to the sampling in monochrome cameras usually employed in DH. This fact has implications in their performance. In this work, we discuss why DSLR cameras are not extensively used for DH, taking into account the problem reported by different authors of object replication. Simulations of DH using monochromatic and DSLR cameras are presented and a theoretical deduction for the replication problem using the Fourier theory is also shown. Experimental results of DH implementation using a DSLR camera show the replication problem.

Polyamidoamine dendrimer hydrogel for enhanced delivery of antiglaucoma drugs.

PubMed

Holden, Christopher A; Tyagi, Puneet; Thakur, Ashish; Kadam, Rajendra; Jadhav, Gajanan; Kompella, Uday B; Yang, Hu

2012-07-01

Dendrimer hydrogel (DH), made from ultraviolet-cured polyamidoamine dendrimer G3.0 tethered with three polyethylene glycol (PEG, 12,000 Da)-acrylate chains (8.1% w/v) in pH 7.4 phosphate buffered saline (PBS), was studied for the delivery of brimonidine (0.1% w/v) and timolol maleate (0.5% w/v), two antiglaucoma drugs. DH was found to be mucoadhesive to mucin particles and nontoxic to human corneal epithelial cells. DH increased the PBS solubility of brimonidine by 77.6% and sustained the in vitro release of both drugs over 56-72 hours. As compared to eye drop formulations (PBS-drug solutions), DH brought about substantially higher human corneal epithelial cells uptake and significantly increased bovine corneal transport for both drugs. DH increased timolol maleate uptake in bovine corneal epithelium, stroma, and endothelium by 0.4- to 4.6-fold. This work demonstrated that DH can enhance the delivery of antiglaucoma drugs in multiple aspects and represents a novel platform for ocular drug delivery. Dendrimer hydrogel was studied as agent for simultaneous delivery of two anti-glaucoma drugs, one hydrophobic and one hydrophilic. Superiority over standard PBS-based formulation was clearly demonstrated for both drugs. The work may be a novel platform for ocular drug delivery. Copyright © 2012 Elsevier Inc. All rights reserved.

D/H ratios of the inner Solar System.

PubMed

Hallis, L J

2017-05-28

The original hydrogen isotope (D/H) ratios of different planetary bodies may indicate where each body formed in the Solar System. However, geological and atmospheric processes can alter these ratios through time. Over the past few decades, D/H ratios in meteorites from Vesta and Mars, as well as from S- and C-type asteroids, have been measured. The aim of this article is to bring together all previously published data from these bodies, as well as the Earth, in order to determine the original D/H ratio for each of these inner Solar System planetary bodies. Once all secondary processes have been stripped away, the inner Solar System appears to be relatively homogeneous in terms of water D/H, with the original water D/H ratios of Vesta, Mars, the Earth, and S- and C-type asteroids all falling between δD values of -100‰ and -590‰. This homogeneity is in accord with the 'Grand tack' model of Solar System formation, where giant planet migration causes the S- and C-type asteroids to be mixed within 1 AU to eventually form the terrestrial planets.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Authors.

D/H ratios of the inner Solar System

NASA Astrophysics Data System (ADS)

Hallis, L. J.

2017-04-01

The original hydrogen isotope (D/H) ratios of different planetary bodies may indicate where each body formed in the Solar System. However, geological and atmospheric processes can alter these ratios through time. Over the past few decades, D/H ratios in meteorites from Vesta and Mars, as well as from S- and C-type asteroids, have been measured. The aim of this article is to bring together all previously published data from these bodies, as well as the Earth, in order to determine the original D/H ratio for each of these inner Solar System planetary bodies. Once all secondary processes have been stripped away, the inner Solar System appears to be relatively homogeneous in terms of water D/H, with the original water D/H ratios of Vesta, Mars, the Earth, and S- and C-type asteroids all falling between δD values of -100‰ and -590‰. This homogeneity is in accord with the `Grand tack' model of Solar System formation, where giant planet migration causes the S- and C-type asteroids to be mixed within 1 AU to eventually form the terrestrial planets. This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'.

D/H ratios of the inner Solar System

PubMed Central

2017-01-01

The original hydrogen isotope (D/H) ratios of different planetary bodies may indicate where each body formed in the Solar System. However, geological and atmospheric processes can alter these ratios through time. Over the past few decades, D/H ratios in meteorites from Vesta and Mars, as well as from S- and C-type asteroids, have been measured. The aim of this article is to bring together all previously published data from these bodies, as well as the Earth, in order to determine the original D/H ratio for each of these inner Solar System planetary bodies. Once all secondary processes have been stripped away, the inner Solar System appears to be relatively homogeneous in terms of water D/H, with the original water D/H ratios of Vesta, Mars, the Earth, and S- and C-type asteroids all falling between δD values of −100‰ and −590‰. This homogeneity is in accord with the ‘Grand tack’ model of Solar System formation, where giant planet migration causes the S- and C-type asteroids to be mixed within 1 AU to eventually form the terrestrial planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’. PMID:28416726

Correlation between IL36α and IL17 and Activity of the Disease in Selected Autoimmune Blistering Diseases

PubMed Central

Woźniacka, Anna; Ociepa, Kamila; Waszczykowska, Elżbieta

2017-01-01

Dermatitis herpetiformis (DH), bullous pemphigoid (BP), and pemphigus vulgaris (PV) are autoimmune bullous skin conditions with eosinophilic and neutrophilic infiltrations. While cytokines are crucial for the affinity and activation of different leukocyte cells in the inflammation and blister formation, there are no studies concerning a role of IL-36. The goal of the study was to analyze whether interleukin 36 is involved in pathogenesis of DH, BP, and PV. And the second aim of the study was the estimation of correlation between Il-36 and IL-17 and titers of specific antibodies in these diseases. Expression of IL-36 and IL-17 was detected in serum in all DH, BP, and PV samples. Serum levels of IL-36 and IL-17α were statistically higher in DH, BP, and PV groups as compared to the control group. IL-36α levels were statistically higher in DH patients, as compared to patients with PV and BP. Our results showed that IL-36 may be helpful in the diagnostic and monitoring of the activity of the disease. IL 36 may play a relevant role of enrolling eosinophils and neutrophils in DH, BP, and PV and finally provoke tissue injury. PMID:28611508

IL-17 Expression in Dermatitis Herpetiformis and Bullous Pemphigoid

PubMed Central

Wagrowska-Danilewicz, Malgorzata; Stasikowska-Kanicka, Olga; Cynkier, Anna; Sysa-Jedrzejowska, Anna; Waszczykowska, Elzbieta

2013-01-01

Dermatitis herpetiformis (DH) and bullous pemphigoid (BP) are skin diseases associated with eosinophilic and neutrophilic infiltrations. Although cytokines are critical for the inflammatory process, there are single findings concerning concentration of IL-17 in bullous diseases. The goal of this study was to assess IL-17 expression in DH and BP patients. Skin biopsies were taken from 10 DH, 14 BP patients and from 10 healthy subjects. The localization and expression of IL-17 was studied by immunohistochemistry and the serum concentration was measured by immunoassays. Expression of IL-17 in the epidermis and in influxed cells in dermis was detected in skin biopsies. Expression of IL-17 was statistically higher in epidermis and infiltration cells in specimens from BP than from DH patients. Examined interleukin expression was detected in perilesional skin of all patients but it was much lower than in lesional skin. The expression of IL-17 was not observed in biopsies from healthy people. Serum level of IL-17 was statistically higher in BP and DH groups as compared to control group. Our results provide the evidence that IL-17 may play an essential role in activating and recruiting eosinophils and neutrophils, which ultimately contribute to the tissue damage in DH and BP. PMID:23970818

Four new cases of double heterozygosity for BRCA1 and BRCA2 gene mutations: clinical, pathological, and family characteristics.

PubMed

Zuradelli, Monica; Peissel, Bernard; Manoukian, Siranoush; Zaffaroni, Daniela; Barile, Monica; Pensotti, Valeria; Cavallari, Ugo; Masci, Giovanna; Mariette, Frederique; Benski, Anne Caroline; Santoro, Armando; Radice, Paolo

2010-11-01

Double heterozygosity (DH) for BRCA1 and BRCA2 mutations is a very rare finding, particularly in non-Ashkenazi individuals, and only a few cases have been reported to date. In addition, little is known on the pathological features of the tumors that occur in DH cases and on their family history of cancer. Four carriers of pathogenic mutations in both BRCA1 and BRCA2 were identified among women who underwent genetic counseling for hereditary susceptibility to breast and ovarian carcinoma at three different Italian institutions. Clinical, pathological, and family history data were collected from medical records and during genetic counseling sessions. All identified DH cases developed breast carcinoma and three of them were also diagnosed with ovarian carcinoma. Mean ages of breast and ovarian cancer diagnosis were 42.7 and 48.6 years, respectively. The majority of breast cancers showed a BRCA1-related phenotype, being negative for hormone receptors and HER2. Two cases reported different gastrointestinal tumors among relatives. Although the individuals described in this study show more severe clinical features in comparison to previously reported BRCA1 and BRCA2 DH cases, our observations support the hypothesis of a non specific phenotype of DH cases in terms of age of disease onset. In addition, our observations indicate that in DH patients breast carcinogenesis appears to be driven mainly by the mutations in BRCA1. The possible association of DH for BRCA gene mutations with gastrointestinal tumors is in keeping with previous reports, but needs to be confirmed by further analyses.

The Cycles of Gaseous Baryons between the Disk and Halo

NASA Astrophysics Data System (ADS)

Zheng, Yong

2018-01-01

The disks of galaxies closely interact with the circumgalactic medium (CGM) through the disk-halo (D/H) interface. The disks grow by inflows from the CGM, while the CGM is enriched, stirred, and heated by outflows from the disks. Recent years have seen great breakthroughs in observations of inflows and outflows at the D/H interface; however, inflow detections are still rare and the structure of the D/H interface is unclear. My thesis work includes searching for inflows and studying the multiphase gas at the D/H interface, and building my expertise in both UV spectroscopy and HI 21cm observations.I will first show HST/COS observations of gas inflows detected in Si IV absorption lines at M33’s D/H interface (Zheng et al. 2017a); this is among the first to unambiguously reveal the existence of disk-wide galactic inflows. The detection of Si IV-bearing inflows indicates that baryons are efficiently recycled between the disk and halo, mostly consistent with a galactic fountain scenario. Then I will present a 3-dimensional kinematic model of the Milky Way (MW)’s D/H interface. I will show that beyond the MW’s D/H interface, there is a significant amount of baryons in the MW’s CGM moving at low velocities (|vlsr|<100 km/s; Zheng et al. 2015, Zheng et al. 2017c). Current MW’s CGM mass estimates suffer from an inside-out observational bias: local observers miss more than half of the gas mass in the MW’s CGM that is blocked out in high-velocity focused studies.

cDNA cloning and sequence determination of the pheromone biosynthesis activating neuropeptide from the seabuckthorn carpenterworm, Holcocerus hippophaecolus (Lepidoptera: Cossidae).

PubMed

Li, Juan; Zhou, Jiao; Sun, Rongbo; Zhang, Haolin; Zong, Shixiang; Luo, Youqing; Sheng, Xia; Weng, Qiang

2013-04-01

The PBAN (pheromone biosynthesis activating neuropeptide)/pyrokinin peptides comprise a major neuropeptide family characterized by a common FXPRL amide at the C-terminus. These peptides are actively involved in many essential endocrine functions. For the first time, we reported the cDNA cloning and sequence determination of the PBAN from the seabuckthorn carpenterworm, Holcocerus hippophaecolus, by using rapid amplification of cDNA ends. The full-length cDNA of Hh-DH-PBAN contained five peptides: diapause hormone (DH) homolog, α-neuropeptide (NP), β-NP, PBAN, and γ-NP. All of the peptides were amidated at their C-terminus and shared a conserved motif, FXPR (or K) L. Moreover, Hh-DH-PBAN had high homology to the other members of the PBAN peptide family: 56% with Manduca sexta, 66% with Bombyx mori, 77% with Helicoverpa zea, and 47% with Plutella xylostella. Phylogenetic analysis revealed that Hh-DH-PBAN was closely related to PBANs from Noctuidae, demonstrated by the relatively higher similarity compared with H. zea. In addition, real-time quantitative PCR (qRT-PCR) analysis showed that Hh-DH-PBAN mRNA expression peaked in the brain-subesophageal ganglion (Br-SOG) complex, and was also detected at high levels during larval and adult stages. The expression decreased significantly after pupation. These results provided information concerning molecular structure characteristics of Hh-DH-PBAN, whose expression profile suggested that the Hh-DH-PBAN gene might be correlated with larval development and sex pheromone biosynthesis in females of the H. hippophaecolus. 2013 Wiley Periodicals, Inc

Constitutive NADPH-dependent electron transferase activity of the Nox4 dehydrogenase domain.

PubMed

Nisimoto, Yukio; Jackson, Heather M; Ogawa, Hisamitsu; Kawahara, Tsukasa; Lambeth, J David

2010-03-23

NADPH oxidase 4 (Nox4) is constitutively active, while Nox2 requires the cytosolic regulatory subunits p47(phox) and p67(phox) and activated Rac with activation by phorbol 12-myristate 13-acetate (PMA). This study was undertaken to identify the domain on Nox4 that confers constitutive activity. Lysates from Nox4-expressing cells exhibited constitutive NADPH- but not NADH-dependent hydrogen peroxide production with a K(m) for NADPH of 55 +/- 10 microM. The concentration of Nox4 in cell lysates was estimated using Western blotting and allowed calculation of a turnover of approximately 200 mol of H(2)O(2) min(-1) (mol of Nox4)(-1). A chimeric protein (Nox2/4) consisting of the Nox2 transmembrane (TM) domain and the Nox4 dehydrogenase (DH) domain showed H(2)O(2) production in the absence of cytosolic regulatory subunits. In contrast, chimera Nox4/2, consisting of the Nox4 TM and Nox2 DH domains, exhibited PMA-dependent activation that required coexpression of regulatory subunits. Nox DH domains from several Nox isoforms were purified and evaluated for their electron transferase activities. Nox1 DH, Nox2 DH, and Nox5 DH domains exhibited barely detectable activities toward artificial electron acceptors, while the Nox4 DH domain exhibited significant rates of reduction of cytochrome c (160 min(-1), largely superoxide dismutase-independent), ferricyanide (470 min(-1)), and other electron acceptors (artificial dyes and cytochrome b(5)). Rates were similar to those observed for H(2)O(2) production by the Nox4 holoenzyme in cell lysates. The activity required added FAD and was seen with NADPH but not NADH. These results indicate that the Nox4 DH domain exists in an intrinsically activated state and that electron transfer from NADPH to FAD is likely to be rate-limiting in the NADPH-dependent reduction of oxygen by holo-Nox4.

Differential fMRI Activation Patterns to Noxious Heat and Tactile Stimuli in the Primate Spinal Cord

PubMed Central

Yang, Pai-Feng; Wang, Feng

2015-01-01

Mesoscale local functional organizations of the primate spinal cord are largely unknown. Using high-resolution fMRI at 9.4 T, we identified distinct interhorn and intersegment fMRI activation patterns to tactile versus nociceptive heat stimulation of digits in lightly anesthetized monkeys. Within a spinal segment, 8 Hz vibrotactile stimuli elicited predominantly fMRI activations in the middle part of ipsilateral dorsal horn (iDH), along with significantly weaker activations in ipsilateral (iVH) and contralateral (cVH) ventral horns. In contrast, nociceptive heat stimuli evoked widespread strong activations in the superficial part of iDH, as well as in iVH and contralateral dorsal (cDH) horns. As controls, only weak signal fluctuations were detected in the white matter. The iDH responded most strongly to both tactile and heat stimuli, whereas the cVH and cDH responded selectively to tactile versus nociceptive heat, respectively. Across spinal segments, iDH activations were detected in three consecutive segments in both tactile and heat conditions. Heat responses, however, were more extensive along the cord, with strong activations in iVH and cDH in two consecutive segments. Subsequent subunit B of cholera toxin tracer histology confirmed that the spinal segments showing fMRI activations indeed received afferent inputs from the stimulated digits. Comparisons of the fMRI signal time courses in early somatosensory area 3b and iDH revealed very similar hemodynamic stimulus–response functions. In summary, we identified with fMRI distinct segmental networks for the processing of tactile and nociceptive heat stimuli in the cervical spinal cord of nonhuman primates. SIGNIFICANCE STATEMENT This is the first fMRI demonstration of distinct intrasegmental and intersegmental nociceptive heat and touch processing circuits in the spinal cord of nonhuman primates. This study provides novel insights into the local functional organizations of the primate spinal cord for pain and touch, information that will be valuable for designing and optimizing therapeutic interventions for chronic pain management. PMID:26203144

Polyvalent Envelope Glycoprotein Vaccine Elicits a Broader Neutralizing Antibody Response but Is Unable To Provide Sterilizing Protection against Heterologous Simian/Human Immunodeficiency Virus Infection in Pigtailed Macaques

PubMed Central

Cho, Michael W.; Kim, Young B.; Lee, Myung K.; Gupta, Kailash C.; Ross, Will; Plishka, Ron; Buckler-White, Alicia; Igarashi, Tatsuhiko; Theodore, Ted; Byrum, Russ; Kemp, Chris; Montefiori, David C.; Martin, Malcolm A.

2001-01-01

The great difficulty in eliciting broadly cross-reactive neutralizing antibodies (NAbs) against human immunodeficiency virus type 1 (HIV-1) isolates has been attributed to several intrinsic properties of their viral envelope glycoprotein, including its complex quaternary structure, extensive glycosylation, and marked genetic variability. Most previously evaluated vaccine candidates have utilized envelope glycoprotein from a single virus isolate. Here we compare the breadth of NAb and protective immune response following vaccination of pigtailed macaques with envelope protein(s) derived from either single or multiple viral isolates. Animals were challenged with Simian/human immunodeficiency virus strain DH12 (SHIVDH12) following priming with recombinant vaccinia virus(es) expressing gp160(s) and boosting with gp120 protein(s) from (i) LAI, RF, 89.6, AD8, and Bal (Polyvalent); (ii) LAI, RF, 89.6, AD8, Bal, and DH12 (Polyvalent-DH12); (iii) 89.6 (Monovalent-89.6); and (iv) DH12 (Monovalent-DH12). Animals in the two polyvalent vaccine groups developed NAbs against more HIV-1 isolates than those in the two monovalent vaccine groups (P = 0.0054). However, the increased breadth of response was directed almost entirely against the vaccine strains. Resistance to SHIVDH12 strongly correlated with the level of NAbs directed against the virus on the day of challenge (P = 0.0008). Accordingly, the animals in the Monovalent-DH12 and Polyvalent-DH12 vaccine groups were more resistant to the SHIVDH12 challenge than the macaques immunized with preparations lacking a DH12 component (viz. Polyvalent and Monovalent-89.6) (P = 0.039). Despite the absence of any detectable NAb, animals in the Polyvalent vaccine group, but not those immunized with Monovalent-89.6, exhibited markedly lower levels of plasma virus than those in the control group, suggesting a superior cell-mediated immune response induced by the polyvalent vaccine. PMID:11160726

HIV-1 gp140 epitope recognition is influenced by immunoglobulin DH gene segment sequence

PubMed Central

Wang, Yuge; Kapoor, Pratibha; Parks, Robert; Silva-Sanchez, Aaron; Alam, S. Munir; Verkoczy, Laurent; Liao, Hua-Xin; Zhuang, Yingxin; Burrows, Peter; Levinson, Michael; Elgavish, Ada; Cui, Xiangqin; Haynes, Barton F.; Schroeder, Harry

2015-01-01

Complementarity determining region 3 of the immunoglobulin (Ig) H chain (CDR-H3) lies at the center of the antigen binding site where it often plays a decisive role in antigen recognition and binding. Amino acids encoded by the diversity (DH) gene segment are the main component of CDR-H3. Each DH has the potential to rearrange into one of six DH reading frames (RFs), each of which exhibits a characteristic amino acid hydrophobicity signature that has been conserved among jawed vertebrates by natural selection. A preference for use of RF1 promotes the incorporation of tyrosine into CDR-H3 while suppressing the inclusion of hydrophobic or charged amino acids. To test the hypothesis that these evolutionary constraints on DH sequence influence epitope recognition, we used mice with a single DH that has been altered to preferentially use RF2 or inverted RF1. B cells in these mice produce a CDR-H3 repertoire that is enriched for valine or arginine in place of tyrosine. We serially immunized this panel of mice with gp140 from HIV-1 JR-FL isolate and then used ELISA or peptide microarray to assess antibody binding to key or overlapping HIV-1 envelope epitopes. By ELISA, serum reactivity to key epitopes varied by DH sequence. By microarray, sera with Ig CDR-H3s enriched for arginine bound to linear peptides with a greater range of hydrophobicity, but had a lower intensity of binding than sera containing Ig CDR-H3s enriched for tyrosine or valine. We conclude that patterns of epitope recognition and binding can be heavily influenced by DH germline sequence. This may help explain why antibodies in HIV infected patients must undergo extensive somatic mutation in order to bind to specific viral epitopes and achieve neutralization. PMID:26687685

Hybrid incompatibilities are affected by dominance and dosage in the haplodiploid wasp Nasonia

PubMed Central

Beukeboom, Leo W.; Koevoets, Tosca; Morales, Hernán E.; Ferber, Steven; van de Zande, Louis

2015-01-01

Study of genome incompatibilities in species hybrids is important for understanding the genetic basis of reproductive isolation and speciation. According to Haldane's rule hybridization affects the heterogametic sex more than the homogametic sex. Several theories have been proposed that attribute asymmetry in hybridization effects to either phenotype (sex) or genotype (heterogamety). Here we investigate the genetic basis of hybrid genome incompatibility in the haplodiploid wasp Nasonia using the powerful features of haploid males and sex reversal. We separately investigate the effects of heterozygosity (ploidy level) and sex by generating sex reversed diploid hybrid males and comparing them to genotypically similar haploid hybrid males and diploid hybrid females. Hybrid effects of sterility were more pronounced than of inviability, and were particularly strong in haploid males, but weak to absent in diploid males and females, indicating a strong ploidy level but no sex specific effect. Molecular markers identified a number of genomic regions associated with hybrid inviability in haploid males that disappeared under diploidy in both hybrid males and females. Hybrid inviability was rescued by dominance effects at some genomic regions, but aggravated or alleviated by dosage effects at other regions, consistent with cytonuclear incompatibilities. Dosage effects underlying Bateson–Dobzhansky–Muller (BDM) incompatibilities need more consideration in explaining Haldane's rule in diploid systems. PMID:25926847

Nuclear inner membrane fusion facilitated by yeast Jem1p is required for spindle pole body fusion but not for the first mitotic nuclear division during yeast mating.

PubMed

Nishikawa, Shuh-ichi; Hirata, Aiko; Endo, Toshiya

2008-11-01

During mating of budding yeast, Saccharomyces cerevisiae, two haploid nuclei fuse to produce a diploid nucleus. The process of nuclear fusion requires two J proteins, Jem1p in the endoplasmic reticulum (ER) lumen and Sec63p, which forms a complex with Sec71p and Sec72p, in the ER membrane. Zygotes of mutants defective in the functions of Jem1p or Sec63p contain two haploid nuclei that were closely apposed but failed to fuse. Here we analyzed the ultrastructure of nuclei in jem1 Delta and sec71 Delta mutant zygotes using electron microscope with the freeze-substituted fixation method. Three-dimensional reconstitution of nuclear structures from electron microscope serial sections revealed that Jem1p facilitates nuclear inner-membrane fusion and spindle pole body (SPB) fusion while Sec71p facilitates nuclear outer-membrane fusion. Two haploid SPBs that failed to fuse could duplicate, and mitotic nuclear division of the unfused haploid nuclei started in jem1 Delta and sec71 Delta mutant zygotes. This observation suggests that nuclear inner-membrane fusion is required for SPB fusion, but not for SPB duplication in the first mitotic cell division.

Stability of transgene integration and expression in subsequent generations of doubled haploid oilseed rape transformed with chitinase and beta-1,3-glucanase genes in a double-gene construct.

PubMed

Melander, Margareta; Kamnert, Iréne; Happstadius, Ingrid; Liljeroth, Erland; Bryngelsson, Tomas

2006-09-01

A double-gene construct with one chitinase and one beta-1,3-glucanase gene from barley, both driven by enhanced 35S promoters, was transformed into oilseed rape. From six primary transformants expressing both transgenes 10 doubled haploid lines were produced and studied for five generations. The number of inserted copies for both the genes was determined by Southern blotting and real-time PCR with full agreement between the two methods. When copy numbers were analysed in different generations, discrepancies were found, indicating that at least part of the inserted sequences were lost in one of the alleles of some doubled haploids. Chitinase and beta-1,3-glucanase expression was analysed by Western blotting in all five doubled haploid generations. Despite that both the genes were present on the same T-DNA and directed by the same promoter their expression pattern between generations was different. The beta-1,3-glucanase was expressed at high and stable levels in all generations, while the chitinase displayed lower expression that varied between generations. The transgenic plants did not show any major impact on fungal resistance when assayed in greenhouse, although purified beta-1,3-glucanase and chitinase caused retardment of fungal growth in vitro.

Mapping PrBn and Other Quantitative Trait Loci Responsible for the Control of Homeologous Chromosome Pairing in Oilseed Rape (Brassica napus L.) Haploids

PubMed Central

Liu, Zhiqian; Adamczyk, Katarzyna; Manzanares-Dauleux, Maria; Eber, Frédérique; Lucas, Marie-Odile; Delourme, Régine; Chèvre, Anne Marie; Jenczewski, Eric

2006-01-01

In allopolyploid species, fair meiosis could be challenged by homeologous chromosome pairing and is usually achieved by the action of homeologous pairing suppressor genes. Oilseed rape (Brassica napus) haploids (AC, n = 19) represent an attractive model for studying the mechanisms used by allopolyploids to ensure the diploid-like meiotic pairing pattern. In oilseed rape haploids, homeologous chromosome pairing at metaphase I was found to be genetically based and controlled by a major gene, PrBn, segregating in a background of polygenic variation. In this study, we have mapped PrBn within a 10-cM interval on the C genome linkage group DY15 and shown that PrBn displays incomplete penetrance or variable expressivity. We have identified three to six minor QTL/BTL that have slight additive effects on the amount of pairing at metaphase I but do not interact with PrBn. We have also detected a number of other loci that interact epistatically, notably with PrBn. Our results support the idea that, as in other polyploid species, metaphase I homeologous pairing in oilseed rape haploids is controlled by an integrated system of several genes, which function in a complex manner. PMID:16951054

D/H Ratios From Sierra Nevada Varved Lake Sediments Record Decadal Hydroclimate Variability During The Medieval Period

NASA Astrophysics Data System (ADS)

Roach, L. D.; Cayan, D. R.; Sessions, A. L.; Charles, C. D.; Anderson, R. S.

2009-12-01

Assessment of the risks of persistent drought requires multiple realizations of decadal and centennial scale hydroclimate variability that extend beyond the relatively short period of instrumental record. Much remains to be learned about the so called “mega droughts” in the Sierra Nevada Mountains, where various lines of evidence point toward the occurrence of severe, decades-long droughts during Medieval times, approximately 900-1400 AD. Here we present a continuous, decadal scale record of hydroclimate variability in the Sierra Nevada Mountains that extends through the heart of the purported Medieval mega droughts. Previous work on the stable hydrogen isotope (D/H) ratios of refractory plant lipid compounds stored in lake sediments demonstrated that these compounds reflect the D/H values of lake water and/or shallow ground water--reservoirs both fed by local precipitation. Lake sediment D/H can therefore reflect the processes that determine D/H of precipitation, including temperature, humidity and moisture source. We have measured D/H of aquatic and terrestrial plant fatty acids extracted from a suite of sediment cores collected at Swamp Lake (elevation: 1554m), in Yosemite National Park, along the Sierra Nevada crest. Measurements with biennial resolution were made for two time periods: the 20th century and the 13th-15th centuries. D/H fluctuations in 20th century sediment contain relatively strong decadal structure. Comparison with instrumentally recorded climate variability reveals that lower D/H concentrations are associated with years of higher than normal annual precipitation, cooler than normal wintertime temperatures, and positive April 1 Snow Water Equivalent (SWE) anomalies throughout the Sierra Nevada, (and conversely for elevated D/H concentrations). The range of variability is approximately 50‰. These associations may be driven by the variable mass-balance impact of evaporation on the isotopic composition of lake water and shallow groundwater in the Swamp Lake watershed, depending on the extent to which these reservoirs are replenished seasonally by wintertime precipitation. Throughout the Medieval period, we observe significant (>30‰), reproducible D/H variability that also fluctuates on multi-year to decadal time scales, with mean values falling within the same range as those recorded over the 20th century. Strong covariance among the aquatic and terrestrial plant fatty acids analyzed, along with the mean values, lends confidence that primary isotopic signatures have been retained. These results can therefore be compared directly to other measures of hydroclimate variability throughout the last millennium, offering a unique new perspective on the mega-drought intervals.

[Determination of deuterium concentration in foods and influence of water with modified isotopic composition on oxidation parameters and heavy hydrogen isotopes content in experimental animals].

PubMed

Basov, A A; Bykov, I M; Baryshev, M G; Dzhimak, S S; Bykov, M I

2014-01-01

The article presents the results of the study of the deuterium (D) content in food products as well as the influence of deuterium depleted water (DDW) on the concentration of heavy hydrogen isotopes in the blood and lyophilized tissues of rats. The most significant difference in the content of D was found between potato and pork fat, which indexes the standard delta notation (δ) D in promille, related to the international standard SMOW (Standard Mean Ocean of Water) amounted to -83,2 per thousand and -250,7 per thousand, respectively (p<0,05). Among the investigated samples of water deuterium concentration ranged from -75,5 per thousand (Narzan) to +72,1 per thousand (Kubai), that indicates the ability of some food products to increase the concentration of heavy hydrogen atoms in the body. The data obtained in the experimental modeling of the diet of male Wistar rats in the age of 5-6 mo (weight 235 ± 16 g) using DDW (δD = -743,2 per thousand) instead of drinking water (δD = -37,0 per thousand) with identical mineral composition showed that after 2 weeks significant (p <0,05) formation of isotopic (deuterium-protium, D/H) gradient in the body is possible. Changing the direction of isotopic D/H gradient in laboratory animals in comparison with its physiological indicators (72-127 per thousand, "plasma>tissue") is due to different rates ofisotopic exchange reactions in plasma and tissues (liver, kidney, heart), which can be explained by entering into the composition of a modified diet of organic substrates with more than DDW concentration D, which are involved in the construction of cellular structures and eventually lead to a redistribution of D and change direction of D/H gradient "plasma

Variants of glycerol dehydrogenase having D-lactate dehydrogenase activity and uses thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Qingzhao; Shanmugam, Keelnatham T.; Ingram, Lonnie O'Neal

The present invention provides methods of designing and generating glycerol dehydrogenase (GlyDH) variants that have altered function as compared to a parent polypeptide. The present invention further provides nucleic acids encoding GlyDH polypeptide variants having altered function as compared to the parent polypeptide. Host cells comprising polynucleotides encoding GlyDH variants and methods of producing lactic acids are also provided in various aspects of the invention.

In Situ Immobilization of Heavy-Metal Contaminated Soil

DTIC Science & Technology

1988-06-01

Scavenging DH 524 Molecules DH 565 DH 566 Natural Materials Clays Slurry BEN 125 Bentonite 325 Bentonite HPM 20 Microfine Bentonite Attasorb LVM Satintone...HPM 20 Microfine Bentonite are sodium- montmorillonite clays of different particle sizes and purities. Na- montmorillonite clay is a three-layered...a powder of 325 Mesh and has a purity of 90 percent. - -PM 20 Microfine Bentonite (Reference 24). This is a microfine clay having a purity of 99.75

The History of Structural Fatigue Testing at Fishermans Bend Australia

DTIC Science & Technology

2005-10-01

Aviation DH de Havilland Aircraft (UK) DOA Department of Aviation DSTO Defence Science and Technology Organisation ESH Equivalent Service Hours...gave early evidence of the truth of Mr. Wills’s predictions and greatly influenced the fatigue research programme. In October 1951 a de Havilland (DH...crack growth [22]. At about this time (in 1953) fatigue failures occurred in the fuselage of the DH Comet which led to the loss of two aircraft with

Development and characterization of microsatellite loci for the haploid–diploid red seaweed Gracilaria vermiculophylla

PubMed Central

Byers, James E.; Greig, Thomas W.; Strand, Allan E.; Weinberger, Florian

2015-01-01

Microsatellite loci are popular molecular markers due to their resolution in distinguishing individual genotypes. However, they have rarely been used to explore the population dynamics in species with biphasic life cycles in which both haploid and diploid stages develop into independent, functional organisms. We developed microsatellite loci for the haploid–diploid red seaweed Gracilaria vermiculophylla, a widespread non-native species in coastal estuaries of the Northern hemisphere. Forty-two loci were screened for amplification and polymorphism. Nine of these loci were polymorphic across four populations of the extant range with two to eleven alleles observed. Mean observed and expected heterozygosities ranged from 0.265 to 0.527 and 0.317 to 0.387, respectively. Overall, these markers will aid in the study of the invasive history of this seaweed and further studies on the population dynamics of this important haploid–diploid primary producer. PMID:26339541

Evidence for Primordial Water in Earths Deep Mantle: D/h Ratios in Baffin Island and Icelandic Picrites

NASA Astrophysics Data System (ADS)

Hallis, L. J.; Huss, G. R.; Nagashima, K.; Taylor, J.; Hilton, D. R.; Mottl, M. J.; Meech, K. J.; Halldorsson, S. A.

2016-12-01

Experimentally based chemical models suggest Jeans escape could have caused an increase in Earth's atmospheric D/H ratio of between a factor of 2 and 9 since the planets formation1. Plate tectonic mixing ensures this change has been incorporated into the mantle. In addition, collisions with hydrogen bearing planetesimals or cometary material after Earth's accretion could have altered the D/H ratio of the planet's surface and upper mantle2. Therefore, to determine Earth's original D/H ratio, a reservoir that has been completely unaffected by these surface and upper mantle changes is required. Most studies suggest that high 3He/4He ratios in some OIBs indicate the existence of relatively undegassed regions in the deep mantle compared to the upper mantle, which retain a greater proportion of their primordial He3-4. Early Tertiary (60-million-year-old) picrites from Baffin Island and west Greenland, which represent volcanic rocks from the proto/early Iceland mantle plume, contain the highest recorded terrestrial 3He/4He ratios3-4. These picrites also have Pb and Nd isotopic ratios consistent with primordial mantle ages (4.45 to 4.55 Ga)5, indicating the persistence of an ancient, isolated reservoir in the mantle. The undegassed and primitive nature6of this reservoir suggests that it could preserve Earth's initial D/H ratio. We measured the D/H ratios of olivine-hosted glassy melt inclusions in Baffin Island and Icelandic picrites to establish whether their deep mantle source region exhibits a different D/H ratio to known upper mantle and surface reservoirs. Baffin Island D/H ratios were found to extend lower than any previously measured mantle values (δD -97 to -218 ‰), suggesting that areas of the deep mantle do preserve a more primitive hydrogen reservoir, hence are unaffected by plate tectonic mixing. Comparing our measured low D/H ratios to those of known extra-terrestrial materials can help determine where Earths water came from. References: [1] Genda and Ikoma, 2008 Icarus 194, 42-52. [2] Abramov, and Mojzsis, (2009) Nature 459, 419-422. [3] Stuart et al. (2003) Nature 424, 57-59. [4] Starkey et al. (2009) Earth Planet. Sci. Lett. 277, 91-100. [5] Jackson et al. (2010) Nature 466, 853-856. [6] Robillard et al. (1992) Contrib. Mineral. Petrol. 112, 230-241.

Production of haploid plantlets in anther cultures of Albizzia lebbeck L.

PubMed

Gharyal, P K; Rashid, A; Maheshwari, S C

1983-12-01

Anthers of Albizzia lebbeck on B5 medium (BM) supplemented with kinetin (2 mg/l) and 2, 4-D (0.5 mg/l) showed callus initiation from microspores. Differentiation of embryoids and shoots was obtained on BM + BAP (1 mg/l) + IAA (0.5 mg/l) and of roots on BM. Root tip squashes of the regenerated plantlets showed the haploid chromosome number (n=13), confirming the microspore origin of the regenerants.

Mutation induction in haploid yeast after split-dose radiation-exposure. I. Fractionated UV-irradiation.

PubMed

Schenk, K; Zölzer, F; Kiefer, J

1989-01-01

Mutation induction was investigated in wild-type haploid yeast Saccharomyces cerevisiae after split-dose UV-irradiation. Cells were exposed to fractionated 254 nm-UV-doses separated by intervals from 0 to 6 h with incubation either on non-nutrient or nutrient agar between. The test parameter was resistance to canavanine. If modifications of sensitivity due to incubation are appropriately taken into account there is no change of mutation frequency.

QTL mapping of sake brewing characteristics of yeast.

PubMed

Katou, Taku; Namise, Masahiro; Kitagaki, Hiroshi; Akao, Takeshi; Shimoi, Hitoshi

2009-04-01

A haploid sake yeast strain derived from the commercial diploid sake yeast strain Kyokai no. 7 showed better characteristics for sake brewing compared to the haploid laboratory yeast strain X2180-1B, including higher production of ethanol and aromatic components. A hybrid of these two strains showed intermediate characteristics in most cases. After sporulation of the hybrid strain, we obtained 100 haploid segregants of the hybrid. Small-scale sake brewing tests of these segregants showed a smooth continuous distribution of the sake brewing characteristics, suggesting that these traits are determined by multiple quantitative trait loci (QTLs). To examine these sake brewing characteristics at the genomic level, we performed QTL analysis of sake brewing characteristics using 142 DNA markers that showed heterogeneity between the two parental strains. As a result, we identified 25 significant QTLs involved in the specification of sake brewing characteristics such as ethanol fermentation and the production of aromatic components.

Ecotypic variability in the metabolic response of seeds to diurnal hydration-dehydration cycles and its relationship to seed vigor.

PubMed

Bai, Bing; Sikron, Noga; Gendler, Tanya; Kazachkova, Yana; Barak, Simon; Grafi, Gideon; Khozin-Goldberg, Inna; Fait, Aaron

2012-01-01

Seeds in the seed bank experience diurnal cycles of imbibition followed by complete dehydration. These conditions pose a challenge to the regulation of germination. The effect of recurring hydration-dehydration (Hy-Dh) cycles were tested on seeds from four Arabidopsis thaliana accessions [Col-0, Cvi, C24 and Ler]. Diurnal Hy-Dh cycles had a detrimental effect on the germination rate and on the final percentage of germination in Col-0, Cvi and C24 ecotypes, but not in the Ler ecotype, which showed improved vigor following the treatments. Membrane permeability measured by ion conductivity was generally increased following each Hy-Dh cycle and was correlated with changes in the redox status represented by the GSSG/GSH (oxidized/reduced glutathione) ratio. Among the ecotypes, Col-0 seeds displayed the highest membrane permeability, whilst Ler was characterized by the greatest increase in electrical conductivity following Hy-Dh cycles. Following Dh 2 and Dh 3, the respiratory activity of Ler seeds significantly increased, in contrast to the other ecotypes, indicative of a dramatic shift in metabolism. These differences were associated with accession-specific content and patterns of change of (i) cell wall-related laminaribiose and mannose; (ii) fatty acid composition, specifically of the unsaturated oleic acid and α-linoleic acid; and (iii) asparagine, ornithine and the related polyamine putrescine. Furthermore, in the Ler ecotype the content of the tricarboxylic acid (TCA) cycle intermediates fumarate, succinate and malate increased in response to dehydration, in contrast to a decrease in the other three ecotypes. These findings provide a link between seed respiration, energy metabolism, fatty acid β-oxidation, nitrogen mobilization and membrane permeability and the improved germination of Ler seeds following Hy-Dh cycles.

Derivative of bardoxolone methyl, dh404, in an inverse dose-dependent manner lessens diabetes-associated atherosclerosis and improves diabetic kidney disease.

PubMed

Tan, Sih Min; Sharma, Arpeeta; Stefanovic, Nada; Yuen, Derek Y C; Karagiannis, Tom C; Meyer, Colin; Ward, Keith W; Cooper, Mark E; de Haan, Judy B

2014-09-01

Oxidative stress and inflammation are inextricably linked and play essential roles in the initiation and progression of diabetes complications such as diabetes-associated atherosclerosis and nephropathy. Bolstering antioxidant defenses is an important mechanism to lessen oxidative stress and inflammation. In this study, we have used a novel analog of the NFE2-related factor 2 (Nrf2) agonist bardoxolone methyl, dh404, to investigate its effects on diabetic macrovascular and renal injury in streptozotocin-induced diabetic apolipoprotein E(-/-) mice. We show that dh404, at lower but not higher doses, significantly lessens diabetes-associated atherosclerosis with reductions in oxidative stress (in plasma, urine, and vascular tissue) and proinflammatory mediators tumor necrosis factor-α, intracellular adhesion molecule-1, vascular cell adhesion molecule-1, and monocyte chemotactic protein-1 (MCP-1). We demonstrate that dh404 attenuates functional (urinary albumin-to-creatinine ratio) and structural (mesangial expansion) glomerular injury and improves renal tubular injury. Liver functional and structural studies showed that dh404 is well tolerated. Complementary in vitro studies in normal rat kidney cells showed that dh404 significantly upregulates Nrf2-responsive genes, heme oxygenase-1, NAD(P)H quinone oxidoreductase 1, and glutathione-S transferase, with inhibition of transforming growth factor-β-mediated profibrotic fibronectin, collagen I, and proinflammatory interleukin-6. Higher doses of dh404 were associated with increased expression of proinflammatory mediators MCP-1 and nuclear factor-κB. These findings suggest that this class of compound is worthy of further study to lessen diabetes complications but that dosage needs consideration. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Cost-effectiveness of dihydroartemisinin-piperaquine compared with artemether-lumefantrine for treating uncomplicated malaria in children at a district hospital in Tanzania.

PubMed

Mori, Amani T; Ngalesoni, Frida; Norheim, Ole F; Robberstad, Bjarne

2014-09-15

Dihydroartemisinin-piperaquine (DhP) is highly recommended for the treatment of uncomplicated malaria. This study aims to compare the costs, health benefits and cost-effectiveness of DhP and artemether-lumefantrine (AL) alongside "do-nothing" as a baseline comparator in order to consider the appropriateness of DhP as a first-line anti-malarial drug for children in Tanzania. A cost-effectiveness analysis was performed using a Markov decision model, from a provider's perspective. The study used cost data from Tanzania and secondary effectiveness data from a review of articles from sub-Saharan Africa. Probabilistic sensitivity analysis was used to incorporate uncertainties in the model parameters. In addition, sensitivity analyses were used to test plausible variations of key parameters and the key assumptions were tested in scenario analyses. The model predicts that DhP is more cost-effective than AL, with an incremental cost-effectiveness ratio (ICER) of US$ 12.40 per DALY averted. This result relies on the assumption that compliance to treatment with DhP is higher than that with AL due to its relatively simple once-a-day dosage regimen. When compliance was assumed to be identical for the two drugs, AL was more cost-effective than DhP with an ICER of US$ 12.54 per DALY averted. DhP is, however, slightly more likely to be cost-effective compared to a willingness-to-pay threshold of US$ 150 per DALY averted. Dihydroartemisinin-piperaquine is a very cost-effective anti-malarial drug. The findings support its use as an alternative first-line drug for treatment of uncomplicated malaria in children in Tanzania and other sub-Saharan African countries with similar healthcare infrastructures and epidemiology of malaria.

Kinetics of hydrogen/deuterium exchanges in cometary ices

NASA Astrophysics Data System (ADS)

Faure, Mathilde; Quirico, Eric; Faure, Alexandre; Schmitt, Bernard; Theulé, Patrice; Marboeuf, Ulysse

2015-11-01

The D/H composition of volatile molecules composing cometary ices brings key constraints on the origin of comets, on the extent of their presolar heritage, as well as on the origin of atmospheres and hydrospheres of terrestrial planets. Nevertheless, the D/H composition may have been modified to various extents in the nucleus when a comet approaches the Sun and experiences deep physical and chemical modifications in its subsurface. We question here the evolution of the D/H ratio of organic species by proton exchanges with water ice. We experimentally studied the kinetics of D/H exchanges on the ice mixtures H2O:CD3OD, H2O:CD3ND2 and D2O:HCN. Our results show that fast exchanges occur on the -OH and -NH2 chemical groups, which are processed through hydrogen bonds exchanges with water and by the molecular mobility triggered by structural changes, such as glass transition or crystallization. D/H exchanges kinetic is best described by a second-order kinetic law with activation energies of 4300 ± 900 K and 3300 ± 100 K for H2O:CD3OD and H2O:CD3ND2 ice mixtures, respectively. The corresponding pre-exponential factors ln(A(s-1)) are 25 ± 7 and 20 ± 1, respectively. No exchange was observed in the case of HCN trapped in D2O ice. These results strongly suggest that upon thermal heating (1) -OH and -NH2 chemical groups of any organic molecules loose their primordial D/H composition and equilibrate with water ice, (2) HCN does not experience proton transfer and keeps a primordial D/H composition and (3) C-H chemical groups are not isotopically modified.

Effect of dehydroleucodine on meiosis reinitiation in Bufo arenarum denuded oocytes.

PubMed

Sánchez Toranzo, G; Giordano, O S; López, L A; Bühler, M I

2007-05-01

In amphibian oocytes meiosis, the transition from G2 to M phase is regulated by the maturation promoting factor (MPF), a complex of the cyclin-dependent kinase p34/cdc2 and cyclin B. In immature oocytes there is an inactive complex (pre-MPF), in which cdc2 is phosphorylated on both Thr-161 and Thr-14/Tyr-15 residues. The dephosphorylation of Thr-14/Tyr-15 is necessary for the start of MPF activation and it is induced by the activation of cdc25 phosphatase. Late, to complete the activation, a small amount of active MPF induces an auto-amplification loop of MPF stimulation (MPF amplification). Dehydroleucodine (DhL) is a sesquiterpenic lactone that inhibits mammalian cell proliferation in G2. We asked whether DhL interferes with MPF activation. For this question, the effect of DhL (up to 30 microM) on the resumption of meiosis was evaluated, and visualized by germinal vesicle break down (GVBD), of Bufo arenarum oocytes induced in vitro by either: (i) removing follicle cells; (ii) progesterone stimulation; (iii) VG-content injection; or (iv) injection of mature cytoplasm. The results show that DhL induced GVBD inhibition, in a dose-dependent manner, in spontaneous and progesterone-induced oocyte maturation. Nevertheless, DhL at the doses assayed had no effect on GVBD induced by mature cytoplasm injection, but exerted an inhibitory effect on GVBD induced by GV content. On the basis of these results, we interpreted that DhL does not inhibit MPF amplification and that the target of DhL is any event in the early stages of the cdc25 activation cascade.

A comparative evaluation to assess the efficacy of 5% sodium fluoride varnish and diode laser and their combined application in the treatment of dentin hypersensitivity

PubMed Central

Suri, Isha; Singh, Poonam; Shakir, Quaid Johar; Shetty, Arvind; Bapat, Ranjeet; Thakur, Roshani

2016-01-01

Background: Dentin hypersensitivity (DH) is an age old complaint with a great number of treatment modalities, but none of these are totally effective till date. Lasers being one of the latest treatment options in periodontics, a study was conducted to test the efficacy of diode laser (DL) in DH alone and in comparison with 5% sodium fluoride (NaF) varnish. Aim: The aim of the present study was to compare the effectiveness of 5% topical NaF varnish and 980 nm gallium aluminum arsenide (GaAlAs) DL alone and combination of 5% NaF + 980 nm GaAlAs DL in the management of DH. Materials and Methods: The study was conducted on 120 teeth in thirty patients with DH assessed by tactile and air blast (AB) stimuli measured by visual analog scale (VAS). Teeth were randomly divided into Group 1 (P) placebo-treated control group, Group 2 (NaF) treated by 5% NaF varnish, Group 3 (DL) treated with 980 nm DL, and Group 4 (NaF + DL) treated with both 5% NaF varnish and 980 nm DL (combination group). Results: There was a significant reduction in DH. The VAS reduction percentages were calculated, and there was a significant decrease in DH above all in G4 (NaF + DL) than G3 (DL) and G2 (NaF). Conclusion: Even though all the three groups (2, 3, and 4) showed improvement in terms of DH reduction, 5% NaF varnish with DL showed the best results among all the groups. PMID:27563205

Nutrient Removal Vis-à-Vis Change in Partial Pressure of CO2 During Post-Monsoon Season in a Tropical Lentic and Lotic Aquatic Body: A Comparative Study

NASA Astrophysics Data System (ADS)

Bhattacharyya, Sourav; Chanda, Abhra; Das, Sourav; Akhand, Anirban; Pattanaik, Suchismita; Choudhury, S. B.; Dutta, Dibyendu; Hazra, Sugata

2018-04-01

The rate of nutrient removal and changes in pCO2 (water) were compared between a lentic aquaculture pond [East Kolkata Wetlands (EKW), India] and a lotic estuarine system [Diamond Harbor (DH) in Hugli Estuary, India] during the post-monsoon season (experiencing a similar tropical climate) by means of ex situ microcosm experiment. Though the DH waters were found to be substantial source of CO2 towards atmosphere and EKW waters to be sink for CO2 (according to the initial concentration of CO2), the eight consecutive days microcosm experiment revealed that the nutrient removal and pCO2 reduction efficiency were significantly higher in DH (ΔpCO2—90%) compared to EKW (ΔpCO2—78%). Among the five nutrients studied [dissolved nitrate-nitrogen (NO3-N), dissolved ammonium nitrogen (NH4-N), silicate, phosphate and iron], dissolved NO3-N followed by NH4-N was the most utilized in both EKW and DH. Except silicate, the other nutrients reduced to 78-91% in EKW and 84-99% in DH samples of their initial concentrations. Chlorophyll-a concentration steadily depleted in EKW ( 68-26 mg m-3) during the experiment indicating intense zooplankton grazing, whereas in DH it increased rapidly ( 3.4-23 mg m-3) with decreasing pCO2 (water). The present observations further indicated that regular flushing of EKW aquaculture ponds is required to avoid stagnation of water column which would enhance the zooplankton grazing and hamper the primary production of an otherwise sink of CO2. In DH, controlled freshwater discharge from Farakka and reduction of untreated organic waste might allow the existing phytoplankton community to enhance their photosynthetic activity.

Overexpression of Salmonella enterica serovar Typhi recA gene confers fluoroquinolone resistance in Escherichia coli DH5α.

PubMed

Yassien, M A M; Elfaky, M A

2015-11-01

A spontaneous fluoroquinolone-resistant mutant (STM1) was isolated from its parent Salmonella enterica serovar Typhi (S. Typhi) clinical isolate. Unlike its parent isolate, this mutant has selective resistance to fluoroquinolones without any change in its sensitivity to various other antibiotics. DNA gyrase assays revealed that the fluoroquinolone resistance phenotype of the STM1 mutant did not result from alteration of the fluoroquinolone sensitivity of the DNA gyrase isolated from it. To study the mechanism of fluoroquinolone resistance, a genomic library from the STM1 mutant was constructed in Escherichia coli DH5α and two recombinant plasmids were obtained. Only one of these plasmids (STM1-A) conferred the selective fluoroquinolone resistance phenotype to E. coli DH5α. The chromosomal insert from STM1-A, digested with EcoRI and HindIII restriction endonucleases, produced two DNA fragments and these were cloned separately into pUC19 thereby generating two new plasmids, STM1-A1 and STM1-A2. Only STM1-A1 conferred the selective fluoroquinolone resistance phenotype to E. coli DH5α. Sequence and subcloning analyses of STM1-A1 showed the presence of an intact RecA open reading frame. Unlike that of the wild-type E. coli DH5α, protein analysis of a crude STM1-A1 extract showed overexpression of a 40 kDa protein. Western blotting confirmed the 40 kDa protein band to be RecA. When a RecA PCR product was cloned into pGEM-T and introduced into E. coli DH5α, the STM1-A11 subclone retained fluoroquinolone resistance. These results suggest that overexpression of RecA causes selective fluoroquinolone resistance in E. coli DH5α.

Choice of Bond Dissociation Enthalpies on which to Base the Stabilization Energies of Simple Radicals: DH(R-H)is Preferred because DH(R-Me) is Perturbed by Changes in Chain Branching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poutsma, Marvin L

2008-01-01

The relative stabilization energies of radicals, SE(R ), along the simple series methyl/ethyl/i-propyl/t-butyl are known to vary in spread and even direction dependent on which dissociation enthalpies, DH(R-X), they are based on. Using a highly electronegative X is recognized as unwise, but it is not clear whether a choice of X = Me or X = R might not be preferred over the almost universal use of R = H. The enthalpies of isomerization of C4 radical pairs that vary only in the substitution pattern at the radical center but not in carbon skeleton illustrate that R = H ismore » indeed the better choice. Comparisons in the context of recent predictive models for alkane and radical stability indicate that, while relative DH(R-H) values highlight the desired difference in substitution pattern at the radical center, relative DH(R-Me) values are perturbed by differences in skeletal branching or protobranching which are well-known to affect thermochemistry. As a result, SE(R ) values derived from relative DH(R-Me) values are consistently too small. The same pattern is illustrated for prim, sec, and tert allylic and benzylic radicals (larger SE(R )) and for the parent vinyl, phenyl, and ethynyl radicals (negative SE(R )).« less

[Factors associated with incidence of dengue in Costa Rica].

PubMed

Mena, Nelson; Troyo, Adriana; Bonilla-Carrión, Roger; Calderón-Arguedas, Olger

2011-04-01

Determine the extent to which socioeconomic, demographic, geographic, and climate variables affected the incidence of dengue and dengue hemorrhagic fever (D/DH) in Costa Rica during the period 1999-2007. A correlational epidemiologic study was conducted that analyzed the cumulative incidence of D/DH from 1999 to 2007 and its association with different variables in the country's 81 cantons. Information was obtained from secondary sources, and the independent variables used for the analysis were selected on the basis of their representativeness in terms of sociodemographic, environmental, and health coverage factors that affect the epidemiology of D/DH. These variables were divided into four groups of indicators: demographic, socioeconomic, housing, and climate and geographical. The data were analyzed by means of simple and multiple Poisson regressions. The Costa Rican cantons with a higher incidence of D/DH were located primarily near the coast, coinciding with some of the variables studied. Temperature, altitude, and the human poverty index were the most relevant variables in explaining the incidence of D/DH, while temperature was the most significant variable in the multiple analyses. The analyses made it possible to correlate a higher incidence of D/DH with lower-altitude cantons, higher temperature, and a high human poverty index ranking. This information is relevant as a first step toward prioritizing and optimizing actions for the prevention and control of this disease.

[Selection of acetate-tolerant mutants from Escherichia coli DH5alpha and the metabolic properties of mutant DA19].

PubMed

Zhu, Caiqing; Ye, Qin

2003-08-01

Esherichia coli DH5alpha is one of the widely used host strains in genetic engineering. However, foreign gene expression level in this strain is seriously inhibited due to its great sensitivity to the accumulated metabolite, acetate. This study aimed at improving the tolerance of this strain against acetate. Cells of E. coli DH5alpha were irradiated with 60Co, and subsequently continuous culture of the irradiated cells was conducted with gradual increase in the dilution rate and the selective pressure, acetate concentration in the medium. The mutants were picked up on MA plates which contained 5g/L sodium acetate. 5 strains with great improvement in acetate tolerance were obtained, among which DA19 was the best. In cultivation of DA19 in complex media YPS and YPS2G, the cell density, maximum specific growth rate and acetate produced were respectively 1.17 and 1.05, 1.08 and 1.27, and 0.06 and 0.59 times of those of DH5alpha. In a chemically defined medium, the cell density of DA19 was 3.4-fold of that of DH5alpha. The cell density of DA19 in a medium containing 10g/L sodium acetate was comparable to that of DH5alpha in the same medium without the addition of acetate.

Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b

DOE PAGES

Gu, Wenyu; Farhan Ul Haque, Muhammad; DiSpirito, Alan A.; ...

2016-05-12

It is well-known that M. trichosporium OB3b has two forms of methane monooxygenase responsible for the initial conversion of methane to methanol, a cytoplasmic (soluble) methane monooxygenase (sMMO) and a membrane-associated (particulate) methane monooxygenase (pMMO) and that copper strongly regulates expression of these alternative forms of MMO. More recently, it has been discovered that M. trichosporium OB3b has multiple types of the methanol dehydrogenase (MeDH), i.e. the Mxa-MeDH and Xox-MeDH, and the expression of these two forms is regulated by the availability of the rare earth element, cerium. Here we extend these studies and show that lanthanum, praseodymium, neodymium andmore » samarium also regulate expression of alternative forms of MeDH. The effect of these rare earth elements on MeDH expression, however, was only observed in the absence of copper. Further, a mutant of M. trichosporium OB3b where the Mxa-MeDH was knocked out was able to grow in the presence of lanthanum, praseodymium and neodymium, but was not able to grow in the presence of samarium. In conclusion, collectively these data suggest that multiple levels of gene regulation by metals exist in M. trichosporium OB3b but that copper overrides the effect of other metals by an as yet unknown mechanism.« less

Phytometabolite Dehydroleucodine Induces Cell Cycle Arrest, Apoptosis, and DNA Damage in Human Astrocytoma Cells through p73/p53 Regulation.

PubMed

Bailon-Moscoso, Natalia; González-Arévalo, Gabriela; Velásquez-Rojas, Gabriela; Malagon, Omar; Vidari, Giovanni; Zentella-Dehesa, Alejandro; Ratovitski, Edward A; Ostrosky-Wegman, Patricia

2015-01-01

Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites) may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL), a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment.

Phytometabolite Dehydroleucodine Induces Cell Cycle Arrest, Apoptosis, and DNA Damage in Human Astrocytoma Cells through p73/p53 Regulation

PubMed Central

Bailon-Moscoso, Natalia; González-Arévalo, Gabriela; Velásquez-Rojas, Gabriela; Malagon, Omar; Vidari, Giovanni; Zentella-Dehesa, Alejandro; Ratovitski, Edward A.; Ostrosky-Wegman, Patricia

2015-01-01

Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites) may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL), a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment. PMID:26309132

Volatile Concentrations and H-Isotope Composition of Unequilibrated Eucrites

NASA Technical Reports Server (NTRS)

Sarafian, Adam R.; Nielsen, Sune G.; Marschall, Horst R.; Gaetani, Glenn A.; Hauri, Erik H.; Righter, Kevin; Berger, Eve L.

2017-01-01

Eucrites are among the oldest and best studied asteroidal basalts (1). They represent magmatism that occurred on their parent asteroid, likely 4-Vesta, starting at 4563 Ma and continuing for approx. 30 Myr. Two hypotheses are debated for the genesis of eucrites, a magma ocean model (2), and a mantle partial melting model. In general, volatiles (H, C, F, Cl) have been ignored for eucrites and 4-Vesta, but solubility of wt% levels of H2O are possible at Vestan interior PT conditions. Targeted measurements on samples could aid our understanding considerably. Recent studies have found evidence of volatile elements in eucrites, but quantifying the abundance of volatiles remains problematic (6). Volatile elements have a disproportionately large effect on melt properties and phase stability, relative to their low abundance. The source of volatile elements can be elucidated by examining the hydrogen isotope ratio (D/H), as different H reservoirs have drastically different H isotope compositions. Recent studies of apatite in eucrites have shown that the D/H of 4-Vesta matches that of Earth and carbonaceous chondrites, however, the D/H of apatites may not represent the D/H of a primitive 4-Vesta melt due to the possibility of degassing prior to the crystallization of apatite. Therefore, the D/H of early crystallizing phases must be measured to determine if the D/H of 4-Vesta is equal to that of the Earth and carbonaceous chondrites.

Effect of enzymatic hydrolysis on bioactive properties and allergenicity of cricket (Gryllodes sigillatus) protein.

PubMed

Hall, Felicia; Johnson, Philip E; Liceaga, Andrea

2018-10-01

Food-derived bioactive peptides have gained attention for their role in preventing chronic diseases. Edible insects are viable sources of bioactive peptides owing to their high protein content and sustainable production. In this study, whole crickets (Gryllodes sigillatus) were alcalase-hydrolyzed to a degree of hydrolysis (DH) ranging from 15 to 85%. Antioxidant activity, angiotensin converting enzyme (ACE), and dipeptidyl peptidase-4 (DPP-IV)- inhibition of the cricket protein hydrolysates (CPH) were evaluated before and after simulated gastrointestinal digestion (SGD). Antioxidant activity was similar among CPH, whereas ACE and DPP-IV inhibition was greater (p < 0.05) in CPH with 60-85% DH. Bioactivity improved after SGD. CPH allergenicity was evaluated using human shrimp-allergic sera. All sera positively reacted to tropomyosin in the unhydrolyzed cricket and CPH with 15-50% DH, whereas 60-85% DH showed no reactivity. In conclusion, CPH (60-85% DH) had the greatest bioactive potential and lowest reactivity to tropomyosin, compared with other CPH and the unhydrolyzed control. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhancement of organic matter degradation and methane gas production of anaerobic granular sludge by degasification of dissolved hydrogen gas.

PubMed

Satoh, Hisashi; Bandara, Wasala M K R T W; Sasakawa, Manabu; Nakahara, Yoshihito; Takahashi, Masahiro; Okabe, Satoshi

2017-11-01

A hollow fiber degassing membrane (DM) was applied to enhance organic matter degradation and methane gas production of anaerobic granular sludge process by reducing the dissolved hydrogen gas (D-H 2 ) concentration in the liquid phase. DM was installed in the bench-scale anaerobic granular sludge reactors and D-H 2 was removed through DM using a vacuum pump. Degasification improved the organic matter degradation efficiency to 79% while the efficiency was 62% without degasification at 12,000mgL -1 of the influent T-COD concentration. Measurement of D-H 2 concentrations in the liquid phase confirmed that D-H 2 was removed by degasification. Furthermore, the effect of acetate concentrations on the organic matter degradation efficiency was investigated. At acetate concentrations above 3gL -1 , organic matter degradation deteriorated. Degasification enhanced the propionate and acetate degradation. These results suggest that degasification reduced D-H 2 concentration and volatile fatty acids concentrations, prevented pH drop, and subsequent enhanced organic matter degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Degradation pathway of 2-chloroethanol in Pseudomonas stutzeri strain JJ under denitrifying conditions.

PubMed

Dijk, John A; Gerritse, Jan; Schraa, Gosse; Stams, Alfons J M

2004-12-01

The pathway of 2-chloroethanol degradation in the denitrifying Pseudomonas stutzeri strain JJ was investigated. In cell-free extracts, activities of a phenazine methosulfate (PMS)-dependent chloroethanol dehydrogenase, an NAD-dependent chloroacetaldehyde dehydrogenase, and a chloroacetate dehalogenase were detected. This suggested that the 2-chloroethanol degradation pathway in this denitrifying strain is the same as found in aerobic bacteria that degrade chloroethanol. Activity towards primary alcohols, secondary alcohols, diols, and other chlorinated alcohols could be measured in cell-free extracts with chloroethanol dehydrogenase (CE-DH) activity. PMS and phenazine ethosulfate (PES) were used as primary electron acceptors, but not NAD, NADP or ferricyanide. Cells of strain JJ cultured in a continuous culture under nitrate limitation exhibited chloroethanol dehydrogenase activity that was a 12 times higher than in cells grown in batch culture. However, under chloroethanol-limiting conditions, CE-DH activity was in the same range as in batch culture. Cells grown on ethanol did not exhibit CE-DH activity. Instead, NAD-dependent ethanol dehydrogenase (E-DH) activity and PMS-dependent E-DH activity were detected.

The Imprint of Atmospheric Evolution in the D/H of Hesperian Clay Minerals on Mars

NASA Technical Reports Server (NTRS)

Mahaffy, P. R.; Webster, C. R.; Stern, J. C.; Brunner, A. E.; Atreya, S. K.; Conrad, P. G.; Domagal-Goldman, S.; Eigenbrode, J. L.; Flesch, G. J.; Christensen, L. E.;

Mapping of a novel QTL for resistance to cereal cyst nematode in wheat.

PubMed

Williams, K J; Willsmore, K L; Olson, S; Matic, M; Kuchel, H

2006-05-01

Cereal cyst nematode (CCN; Heterodera avenae Woll.) is a root pathogen of cereals that can cause severe yield losses in intolerant wheat cultivars. Loci for resistance to CCN, measured by a seedling bioassay, were identified by creating a genetic map based on a Trident/Molineux doubled haploid population of 182 lines. A novel locus accounting for up to 14% of the resistance to CCN was mapped to chromosome 1B of Molineux by association with microsatellite marker loci Xwmc719 and Xgwm140. This locus acts additively with the previously identified CCN resistance loci identified on chromosomes 6B (Cre8) and 2A (Cre5 on the VPM1 segment) in this population to explain 44% of the genetic variance for this major wheat pathogen.

Toward a theory of topopatric speciation: The role of genetic assortative mating

NASA Astrophysics Data System (ADS)

Schneider, David M.; do Carmo, Eduardo; Martins, Ayana B.; de Aguiar, Marcus A. M.

2014-09-01

We discuss a minimalist model of assortative mating for sexually reproducing haploid individuals with two biallelic loci. Assortativeness is introduced in the model by preventing mating between individuals whose alleles differ at both loci. Using methods of dynamical systems and population genetics we provide a full description of the evolution of the system for the case of very large populations. We derive the equations governing the evolution of haplotype frequencies and study the equilibrium solutions, stability, and speed of convergence to equilibrium. We find a constant of motion which allows us to introduce a geometrical construction that makes it straightforward to predict the fate of initial conditions. Finally, we discuss the consequences of this class of assortative mating models, including their possible extensions and implications for sympatric and topopatric speciation.

Estimating mutation parameters, population history and genealogy simultaneously from temporally spaced sequence data.

PubMed Central

Drummond, Alexei J; Nicholls, Geoff K; Rodrigo, Allen G; Solomon, Wiremu

2002-01-01

Molecular sequences obtained at different sampling times from populations of rapidly evolving pathogens and from ancient subfossil and fossil sources are increasingly available with modern sequencing technology. Here, we present a Bayesian statistical inference approach to the joint estimation of mutation rate and population size that incorporates the uncertainty in the genealogy of such temporally spaced sequences by using Markov chain Monte Carlo (MCMC) integration. The Kingman coalescent model is used to describe the time structure of the ancestral tree. We recover information about the unknown true ancestral coalescent tree, population size, and the overall mutation rate from temporally spaced data, that is, from nucleotide sequences gathered at different times, from different individuals, in an evolving haploid population. We briefly discuss the methodological implications and show what can be inferred, in various practically relevant states of prior knowledge. We develop extensions for exponentially growing population size and joint estimation of substitution model parameters. We illustrate some of the important features of this approach on a genealogy of HIV-1 envelope (env) partial sequences. PMID:12136032

Estimating mutation parameters, population history and genealogy simultaneously from temporally spaced sequence data.

PubMed

Drummond, Alexei J; Nicholls, Geoff K; Rodrigo, Allen G; Solomon, Wiremu

2002-07-01

Molecular sequences obtained at different sampling times from populations of rapidly evolving pathogens and from ancient subfossil and fossil sources are increasingly available with modern sequencing technology. Here, we present a Bayesian statistical inference approach to the joint estimation of mutation rate and population size that incorporates the uncertainty in the genealogy of such temporally spaced sequences by using Markov chain Monte Carlo (MCMC) integration. The Kingman coalescent model is used to describe the time structure of the ancestral tree. We recover information about the unknown true ancestral coalescent tree, population size, and the overall mutation rate from temporally spaced data, that is, from nucleotide sequences gathered at different times, from different individuals, in an evolving haploid population. We briefly discuss the methodological implications and show what can be inferred, in various practically relevant states of prior knowledge. We develop extensions for exponentially growing population size and joint estimation of substitution model parameters. We illustrate some of the important features of this approach on a genealogy of HIV-1 envelope (env) partial sequences.

Porous Ni-Mn oxide nanosheets in situ formed on nickel foam as 3D hierarchical monolith de-NOx catalysts

NASA Astrophysics Data System (ADS)

Cai, Sixiang; Zhang, Dengsong; Shi, Liyi; Xu, Jing; Zhang, Lei; Huang, Lei; Li, Hongrui; Zhang, Jianping

2014-06-01

In this work, we successfully in situ decorated nickel foam with porous Ni-Mn oxide nanosheets (3DH-NM/NF) as 3D hierarchical monolith de-NOx catalysts via a simple hydrothermal reaction and calcination process. The catalysts were carefully examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, elemental mapping, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and NH3 temperature-programmed desorption measurements. The results indicated that the nanosheets are composed of a Ni6Mn1O8 spinel and the metal species are uniformly dispersed in bi-metal oxides. As a result, the strong synergistic effects between the Mn and Ni species have been observed. The active oxygen species, reducible species and acidity are enhanced by the in situ formation of the nanosheets on the surface of nickel foam. These desirable features of 3DH-NM/NF catalysts bring about the excellent de-NOx performance. Moreover, the 3DH-NM/NF catalysts also present good stability and H2O resistance. Based on these favorable properties, 3DH-NM/NF could be considered as a promising candidate for the monolith de-NOx catalysts.In this work, we successfully in situ decorated nickel foam with porous Ni-Mn oxide nanosheets (3DH-NM/NF) as 3D hierarchical monolith de-NOx catalysts via a simple hydrothermal reaction and calcination process. The catalysts were carefully examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, elemental mapping, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction and NH3 temperature-programmed desorption measurements. The results indicated that the nanosheets are composed of a Ni6Mn1O8 spinel and the metal species are uniformly dispersed in bi-metal oxides. As a result, the strong synergistic effects between the Mn and Ni species have been observed. The active oxygen species, reducible species and acidity are enhanced by the in situ formation of the nanosheets on the surface of nickel foam. These desirable features of 3DH-NM/NF catalysts bring about the excellent de-NOx performance. Moreover, the 3DH-NM/NF catalysts also present good stability and H2O resistance. Based on these favorable properties, 3DH-NM/NF could be considered as a promising candidate for the monolith de-NOx catalysts. Electronic supplementary information (ESI) available: Experimental details and catalytic performance of the NM/cordierite catalysts, SEM image and EDX analysis of the NF and 3DH-N/NF catalysts, N2 selectivity and catalytic performance under different gas hourly space velocities of the 3DH-NM/NF catalysts. See DOI: 10.1039/c4nr00475b

Characterization of microsatellite loci in the Himalayan lichen fungus Lobaria pindarensis (Lobariaceae).

PubMed

Devkota, Shiva; Cornejo, Carolina; Werth, Silke; Chaudhary, Ram Prasad; Scheidegger, Christoph

2014-05-01

Microsatellite loci were developed for the rare, Himalayan, endemic haploid lichen fungus, Lobaria pindarensis, to study its population subdivision and the species' response to forest disturbance and fragmentation. • We developed 18 polymorphic microsatellite markers using 454 pyrosequencing data and assessed them in 109 individuals. The number of alleles per locus ranged from three to 11 with an average of 6.9. Nei's unbiased gene diversity, averaged over loci, ranged from 0.514 to 0.685 in the three populations studied. The cross-amplification success with related species (L. chinensis, L. gyrophorica, L. isidiophora, L. orientalis, L. pulmonaria, L. spathulata, and Lobaria sp.) was generally high and decreased with decreasing relationship to L. pindarensis. • The new markers will allow the study of genetic diversity and differentiation within L. pindarensis across its distribution. Moreover, they will enable us to study the effects of forest management on the genetic population structure of this tree-colonizing lichen and to carry out population genetic studies of related species in East Asia.

An eQTL Analysis of Partial Resistance to Puccinia hordei in Barley

PubMed Central

Chen, Xinwei; Hackett, Christine A.; Niks, Rients E.; Hedley, Peter E.; Booth, Clare; Druka, Arnis; Marcel, Thierry C.; Vels, Anton; Bayer, Micha; Milne, Iain; Morris, Jenny; Ramsay, Luke; Marshall, David; Cardle, Linda; Waugh, Robbie

2010-01-01

Background Genetic resistance to barley leaf rust caused by Puccinia hordei involves both R genes and quantitative trait loci. The R genes provide higher but less durable resistance than the quantitative trait loci. Consequently, exploring quantitative or partial resistance has become a favorable alternative for controlling disease. Four quantitative trait loci for partial resistance to leaf rust have been identified in the doubled haploid Steptoe (St)/Morex (Mx) mapping population. Further investigations are required to study the molecular mechanisms underpinning partial resistance and ultimately identify the causal genes. Methodology/Principal Findings We explored partial resistance to barley leaf rust using a genetical genomics approach. We recorded RNA transcript abundance corresponding to each probe on a 15K Agilent custom barley microarray in seedlings from St and Mx and 144 doubled haploid lines of the St/Mx population. A total of 1154 and 1037 genes were, respectively, identified as being P. hordei-responsive among the St and Mx and differentially expressed between P. hordei-infected St and Mx. Normalized ratios from 72 distant-pair hybridisations were used to map the genetic determinants of variation in transcript abundance by expression quantitative trait locus (eQTL) mapping generating 15685 eQTL from 9557 genes. Correlation analysis identified 128 genes that were correlated with resistance, of which 89 had eQTL co-locating with the phenotypic quantitative trait loci (pQTL). Transcript abundance in the parents and conservation of synteny with rice allowed us to prioritise six genes as candidates for Rphq11, the pQTL of largest effect, and highlight one, a phospholipid hydroperoxide glutathione peroxidase (HvPHGPx) for detailed analysis. Conclusions/Significance The eQTL approach yielded information that led to the identification of strong candidate genes underlying pQTL for resistance to leaf rust in barley and on the general pathogen response pathway. The dataset will facilitate a systems appraisal of this host-pathogen interaction and, potentially, for other traits measured in this population. PMID:20066049

Estimating and Modeling Gene Flow for a Spatially Distributed Species

DTIC Science & Technology

1991-01-01

inherited from each parent’s gamete (sperm or egg) cell. The qsnotype of a diploid individual is the specification of all of its chromosome pairs. It is...sometimes sufficient to model a diploid species as if it were haploid . Haploid individuals have only one of each type of chromosome. We think of a chro...stage for the mathematical models, the necessary genetical terms are collected here. Most organisms are diploid , having chromosome.- in pairs, one

Ploidally antagonistic selection maintains stable genetic polymorphism.

PubMed

Immler, Simone; Arnqvist, Göran; Otto, Sarah Perin

2012-01-01

Understanding the maintenance of genetic variation in the face of selection remains a key issue in evolutionary biology. One potential mechanism for the maintenance of genetic variation is opposing selection during the diploid and haploid stages of biphasic life cycles universal among eukaryotic sexual organisms. If haploid and diploid gene expression both occur, selection can act in each phase, potentially in opposing directions. In addition, sex-specific selection during haploid phases is likely simply because male and female gametophytes/gametes tend to have contrasting life histories. We explored the potential for the maintenance of a stable polymorphism under ploidally antagonistic as well as sex-specific selection. Furthermore, we examined the role of the chromosomal location of alleles (autosomal or sex-linked). Our analyses show that the most permissible conditions for the maintenance of polymorphism occur under negative ploidy-by-sex interactions, where stronger selection for an allele in female than male diploids is coupled with weaker selection against the allele in female than male haploids. Such ploidy-by-sex interactions also promote allele frequency differences between the sexes. With constant fitness, ploidally antagonistic selection can maintain stable polymorphisms for autosomal and X-linked genes but not for Y-linked genes. We discuss the implications of our results and outline a number of biological settings where the scenarios modeled may apply. © 2011 The Author(s). Evolution © 2011 The Society for the Study of Evolution.

Exploratory randomised controlled clinical study to evaluate the comparative efficacy of two occluding toothpastes - a 5% calcium sodium phosphosilicate toothpaste and an 8% arginine/calcium carbonate toothpaste - for the longer-term relief of dentine hypersensitivity.

PubMed

Hall, Claire; Mason, Stephen; Cooke, Jonathan

2017-05-01

To compare the longer-term clinical efficacy of two occlusion-technology toothpastes - a 5% calcium sodium phosphosilicate (CSPS) toothpaste and a commercially available 8% arginine/calcium carbonate toothpaste - in relieving dentine hypersensitivity (DH). Efficacy was also compared with that of a regular fluoride toothpaste control. This was an exploratory, randomised, examiner-blind, parallel-group, 11-week, controlled study in healthy adults with self-reported and clinically diagnosed DH. After an acclimatisation period, subjects were randomised to one of three study treatments with which they brushed their teeth twice daily. Sensitivity was assessed at baseline and after 1, 2, 4, 6 and 11 weeks treatment in response to evaporative (air) and tactile stimuli (measured by the Schiff Sensitivity Scale/visual analogue scale and tactile threshold, respectively). A total of 135 subjects were randomised to treatment. The two occlusion-technology toothpastes performed similarly over the 11-week treatment period. All study treatments showed statistically significant reductions from baseline in DH at all timepoints for all measures (p<0.05). Statistically significant and clinically relevant sensitivity relief was observed for both occluding formulations compared with the regular fluoride toothpaste: for evaporative (air) sensitivity within 1 week and for tactile sensitivity at Week 11. No significant differences were detected between the two occluding formulations at any timepoint, for any endpoint. Study treatments were generally well tolerated. In this exploratory study, a 5% CSPS occluding toothpaste was effective in relieving DH compared with a regular fluoride toothpaste; an 8% arginine/calcium carbonate anti-sensitivity toothpaste provided similar benefits. Improvements in DH continued throughout the 11-week study. Dentine hypersensitivity (DH) is a common and painful condition. Twice-daily use of a 5% calcium sodium phosphosilicate toothpaste reduces DH within 1-2 weeks of initiating use. Ongoing, twice daily use of the sensitivity toothpastes evaluated in this study was associated with continued, clinically significant improvements in DH. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effects of Chronic Alcohol Exposure on the Modulation of Ischemia-Induced Glutamate Release via Cannabinoid Receptors in the Dorsal Hippocampus.

PubMed

Zheng, Lei; Wu, Xiaoda; Dong, Xiao; Ding, Xinli; Song, Cunfeng

2015-10-01

Chronic alcohol consumption is a critical contributing factor to ischemic stroke, as it enhances ischemia-induced glutamate release, leading to more severe excitotoxicity and brain damage. But the neural mechanisms underlying this phenomenon are poorly understood. We evaluated the effects of chronic alcohol exposure on the modulation of ischemia-induced glutamate release via CB1 and CB2 cannabinoid receptors during middle cerebral artery occlusion, using in vivo microdialysis coupled with high-performance liquid chromatography, in alcohol-naïve rats or rats after 1 or 30 days of withdrawal from chronic ethanol intake (6% v/v for 14 days). Intra-dorsal hippocampus (DH) infusions of ACEA or JWH133, selective CB1 or CB2 receptor agonists, respectively, decreased glutamate release in the DH in alcohol-naïve rats in a dose-dependent manner. Such an effect was reversed by co-infusions of SR141716A or AM630, selective CB1 or CB2 receptor antagonists, respectively. After 30 days, but not 1 day of withdrawal, ischemia induced an enhancement in glutamate release in the DH, as compared with non-alcohol-treated control group. Intra-DH infusions of JWH133, but not ACEA, inhibited ischemia-induced glutamate release in the DH after 30 days of withdrawal. Finally, 1 day of withdrawal did not alter the protein level of CB1 or CB2 receptors in the DH, as compared to non-alcohol-treated control rats. Whereas 30 days of withdrawal robustly decreased the protein level of CB1 receptors, but failed to alter the protein level of CB2 receptors, in the DH, as compared to non-alcohol-treated control rats. Together, these findings suggest that loss of expression/function of CB1 receptors, but not CB2 receptors in the DH, is correlated with the enhancement of ischemia-induced glutamate release after prolonged alcohol withdrawal. Copyright © 2015 by the Research Society on Alcoholism.

A retrospective study of dermatitis herpetiformis from an immunobullous disease clinic in north India.

PubMed

Handa, Sanjeev; Dabas, Garima; De, Dipankar; Mahajan, Rahul; Chatterjee, Debajyoti; Saika, Uma N; Radotra, Bishan D

2018-05-11

Indian data on dermatitis herpetiformis (DH) is not available. The aim of this study was to investigate the demographic and clinicopathological characteristics of patients with DH and to study its association with other autoimmune diseases. All data were collected from case record forms of patients registered in immunobullous disease clinic of our institute. The diagnosis was based on characteristic clinical and immuno/histopathological features. A total of 65 patients were included, which constituted 9.47% of the registered patients in the immunobullous disease clinic over 3.5 years. The male to female ratio was 1.4 : 1; the average age was 44.35 ± 15.52 years. Direct immunofluorescence showed granular IgA deposits at the papillary tips in 83.07% and basement membrane zone in 12.3% patients. Sixteen (24.1%) patients had associated celiac disease, and 15 (23.07%) patients had other autoimmune comorbidities such as hypothyroidism. Forty percent of patients on strict gluten-free diet achieved remission in 2 years, while 35.4% had frequent relapses as they continued gluten intake. Dermatitis herpetiformis is not a rare disease in northern India as previously believed. The clinical, histological, and immunopathological characteristics of Indian DH patients are similar to those reported in Caucasian populations. The limitations of our study include an absence of genetic testing for HLA-DQ2 or DQ8, nonavailability of kits for detecting IgA specific for epidermal transglutaminase (IgA eTG), and short follow-up period. © 2018 The International Society of Dermatology.

Mapping quantitative trait loci with additive effects and additive x additive epistatic interactions for biomass yield, grain yield, and straw yield using a doubled haploid population of wheat (Triticum aestivum L.).

PubMed

Li, Z K; Jiang, X L; Peng, T; Shi, C L; Han, S X; Tian, B; Zhu, Z L; Tian, J C

2014-02-28

Biomass yield is one of the most important traits for wheat (Triticum aestivum L.)-breeding programs. Increasing the yield of the aerial parts of wheat varieties will be an integral component of future wheat improvement; however, little is known regarding the genetic control of aerial part yield. A doubled haploid population, comprising 168 lines derived from a cross between two winter wheat cultivars, 'Huapei 3' (HP3) and 'Yumai 57' (YM57), was investigated. Quantitative trait loci (QTL) for total biomass yield, grain yield, and straw yield were determined for additive effects and additive x additive epistatic interactions using the QTLNetwork 2.0 software based on the mixed-linear model. Thirteen QTL were determined to have significant additive effects for the three yield traits, of which six also exhibited epistatic effects. Eleven significant additive x additive interactions were detected, of which seven occurred between QTL showing epistatic effects only, two occurred between QTL showing epistatic effects and additive effects, and two occurred between QTL with additive effects. These QTL explained 1.20 to 10.87% of the total phenotypic variation. The QTL with an allele originating from YM57 on chromosome 4B and another QTL contributed by HP3 alleles on chromosome 4D were simultaneously detected on the same or adjacent chromosome intervals for the three traits in two environments. Most of the repeatedly detected QTL across environments were not significant (P > 0.05). These results have implications for selection strategies in wheat biomass yield and for increasing the yield of the aerial part of wheat.

Alternate pathogenesis of systemic neoplasia in the bivalve mollusc Mytilus.

PubMed

Moore, J D; Elston, R A; Drum, A S; Wilkinson, M T

1991-09-01

The proliferative disease systemic neoplasia, also termed hemic neoplasia or disseminated sarcoma, was studied in four Puget Sound, Washington populations of the bay mussel (Mytilus sp.). Using flow cytometric measurement of DAPI-stained cells withdrawn from the hemolymph, DNA content frequency histograms were generated for 73 individuals affected by the disease. The cells manifesting systemic neoplasia were found to exist as either of two separate types, characterized by G0G1 phase nuclear DNA contents of either approximately 4.9 x haploid (pentaploid form) or approximately 3.8 x haploid (tetraploid form). The two disease forms were found to coexist in all four mussel populations sampled, with overall relative prevalences of 66% pentaploid form, 29% tetraploid form, and 5% exhibiting both disease forms simultaneously. These findings represent the first unequivocal demonstration of multiple cell types in a bivalve neoplasia. The two forms appear to represent separate pathogenetic processes rather than sequential stages of a single pathogenesis. Two cell cycling parameters associated with proliferative activity were employed to compare the alternate forms: (i) the percentage of cells assigned to the DNA Synthesis (S) phase of the neoplastic cell cycle, and (ii) the proportion of neoplastic cell mitotic figures in hemocytological preparations. Mean values for both parameters were significantly higher for mussels with the tetraploid form of the disease, suggesting a higher rate of proliferation relative to the pentaploid form. Qualitatively, cells of the tetraploid form contained slightly lower nuclear and cytoplasmic volumes compared to those of the pentaploid form. An observed wide variation in neoplastic cell nuclear size within either disease form may reflect the distribution of cells in the G0G1, S, and G2M phases of the cell cycle. Potential etiologic relationships between the two forms are discussed.

A method for determining haploid and triploid genotypes and their association with vascular phenotypes in Williams syndrome and 7q11.23 duplication syndrome.

PubMed

Gregory, Michael D; Kolachana, Bhaskar; Yao, Yin; Nash, Tiffany; Dickinson, Dwight; Eisenberg, Daniel P; Mervis, Carolyn B; Berman, Karen F

2018-04-04

Williams syndrome ([WS], 7q11.23 hemideletion) and 7q11.23 duplication syndrome (Dup7) show contrasting syndromic symptoms. However, within each group there is considerable interindividual variability in the degree to which these phenotypes are expressed. Though software exists to identify areas of copy number variation (CNV) from commonly-available SNP-chip data, this software does not provide non-diploid genotypes in CNV regions. Here, we describe a method for identifying haploid and triploid genotypes in CNV regions, and then, as a proof-of-concept for applying this information to explain clinical variability, we test for genotype-phenotype associations. Blood samples for 25 individuals with WS and 13 individuals with Dup7 were genotyped with Illumina-HumanOmni5M SNP-chips. PennCNV and in-house code were used to make genotype calls for each SNP in the 7q11.23 locus. We tested for association between the presence of aortic arteriopathy and genotypes of the remaining (haploid in WS) or duplicated (triploid in Dup7) alleles. Haploid calls in the 7q11.23 region were made for 99.0% of SNPs in the WS group, and triploid calls for 98.8% of SNPs in those with Dup7. The G allele of SNP rs2528795 in the ELN gene was associated with aortic stenosis in WS participants (p < 0.0049) while the A allele of the same SNP was associated with aortic dilation in Dup7. Commonly available SNP-chip information can be used to make haploid and triploid calls in individuals with CNVs and then to relate variability in specific genes to variability in syndromic phenotypes, as demonstrated here using aortic arteriopathy. This work sets the stage for similar genotype-phenotype analyses in CNVs where phenotypes may be more complex and/or where there is less information about genetic mechanisms.

KSC-2009-2433

NASA Image and Video Library

2009-03-30

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, the Science Instrument Command and Data Handling Unit, or SIC&DH, is moved into a clean area. The SIC&DH will be installed on the Hubble Space Telescope during space shuttle Atlantis' STS-125 mission, replacing the one that suffered a failure aboard the orbiting telescope on Sept. 27, 2008. The SIC&DH is being prepared for integration onto the Multi-Use Lightweight Equipment Carrier. The SIC&DH will be installed on the Hubble Space Telescope during space shuttle Atlantis' STS-125 mission, replacing one that suffered a failure aboard the orbiting telescope on Sept. 27, 2008. The carrier holds the payload for space shuttle Atlantis' STS-125 mission servicing NASA's Hubble Space Telescope, targeted to launch May 12. Photo credit: NASA/Jack Pfaller

KSC-2009-2432

NASA Image and Video Library

2009-03-30

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, a technician monitors the lowering of the Science Instrument Command and Data Handling Unit, or SIC&DH, onto a stand. The SIC&DH will be installed on the Hubble Space Telescope during space shuttle Atlantis' STS-125 mission, replacing the one that suffered a failure aboard the orbiting telescope on Sept. 27, 2008. The SIC&DH is being prepared for integration onto the Multi-Use Lightweight Equipment Carrier. The SIC&DH will be installed on the Hubble Space Telescope during space shuttle Atlantis' STS-125 mission, replacing one that suffered a failure aboard the orbiting telescope on Sept. 27, 2008. The carrier holds the payload for space shuttle Atlantis' STS-125 mission servicing NASA's Hubble Space Telescope, targeted to launch May 12. Photo credit: NASA/Jack Pfaller

Mars atmosphere. The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars.

PubMed

Mahaffy, P R; Webster, C R; Stern, J C; Brunner, A E; Atreya, S K; Conrad, P G; Domagal-Goldman, S; Eigenbrode, J L; Flesch, G J; Christensen, L E; Franz, H B; Freissinet, C; Glavin, D P; Grotzinger, J P; Jones, J H; Leshin, L A; Malespin, C; McAdam, A C; Ming, D W; Navarro-Gonzalez, R; Niles, P B; Owen, T; Pavlov, A A; Steele, A; Trainer, M G; Williford, K H; Wray, J J

2015-01-23

The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550° and 950°C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (±0.2) times the ratio in standard mean ocean water. The D/H ratio in this ~3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet. Copyright © 2015, American Association for the Advancement of Science.

Digital Holography and 3D Imaging: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America B.

PubMed

Banerjee, Partha P; Osten, Wolfgang; Picart, Pascal; Cao, Liangcai; Nehmetallah, George

2017-05-01

The OSA Topical Meeting on Digital Holography and 3D Imaging (DH) was held 25-28 July 2016 in Heidelberg, Germany, as part of the Imaging Congress. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. This year, AO and the Journal of the Optical Society of America B (JOSA B) jointly decided to have one such feature issue in each journal. This feature issue includes 31 papers in AO and 11 in JOSA B, and covers a large range of topics, reflecting the rapidly expanding techniques and applications of digital holography and 3D imaging. The upcoming DH meeting (DH 2017) will be held from 29 May to 1 June in Jeju Island, South Korea.

ABA and ABC renewal of conditioned magazine approach are not impaired by dorsal hippocampus inactivation or lesions

PubMed Central

Campese, Vincent; Delamater, Andrew R.

2013-01-01

Three experiments investigated the role of the dorsal hippocampus (DH) in renewal of conditioned and then extinguished magazine approach responding in rats. Experiments 1 and 2 found no effect of muscimol inactivation of the DH during testing on ABA and ABC renewal, respectively. However, subjects from these studies were subsequently found to be impaired on a delayed non-matching-to-place task following muscimol but not saline infusions. Experiment 3 found no effects of post-training excitotoxic lesions of the DH on ABA and ABC renewal. Lesioned subjects were, however, impaired on the delayed non-matching-to-place task compared to control subjects. These findings suggest that the DH may not play a similar role in Pavlovian extinction in appetitive learning tasks as has previously been reported in aversive learning. PMID:23583520

Deuterium fractionation of water in the Solar nebula

NASA Astrophysics Data System (ADS)

Albertsson, Tobias; Semenov, Dmitry; Henning, Thomas

2013-07-01

Water evaporates in the inner regions of protoplanetary disks and is frozen onto grains in the outer regions. Therefore its presence in vast quantities on Earth is puzzling. Subsequent delivery through bombardment by primitive bodies formed in the outer icy regions is the favored mechanism. By studying water D/H ratios one hopes to understand whether the water was mainly delivered by comets or asteroids. Using an extended deuterium chemistry network coupled to a 2D chemo-dynamical disk model, we investigate the evolution of the D/H ratio of water in the young Solar nebula. We find that both the laminar and mixing Solar nebula models show the Earth's ocean water D/H ratio at 2-3 AU. In addition, the 2D-mixing model explains better the water D/H values observed in the Oort- and Jupiter-family comets.

Lunar Reconnaissance Orbiter (LRO) Command and Data Handling Flight Electronics Subsystem

NASA Technical Reports Server (NTRS)

Nguyen, Quang; Yuknis, William; Haghani, Noosha; Pursley, Scott; Haddad, Omar

2012-01-01

A document describes a high-performance, modular, and state-of-the-art Command and Data Handling (C&DH) system developed for use on the Lunar Reconnaissance Orbiter (LRO) mission. This system implements a complete hardware C&DH subsystem in a single chassis enclosure that includes a processor card, 48 Gbytes of solid-state recorder memory, data buses including MIL-STD-1553B, custom RS-422, SpaceWire, analog collection, switched power services, and interfaces to the Ka-Band and S-Band RF communications systems. The C&DH team capitalized on extensive experience with hardware and software with PCI bus design, SpaceWire networking, Actel FPGA design, digital flight design techniques, and the use of VxWorks for the real-time operating system. The resulting hardware architecture was implemented to meet the LRO mission requirements. The C&DH comprises an enclosure, a backplane, a low-voltage power converter, a single-board computer, a communications interface board, four data storage boards, a housekeeping and digital input/output board, and an analog data acquisition board. The interfaces between the C&DH and the instruments and avionics are connected through a SpaceWire network, a MIL-STD-1553 bus, and a combination of synchronous and asynchronous serial data transfers over RS-422 and LVDS (low-voltage differential-signaling) electrical interfaces. The C&DH acts as the spacecraft data system with an instrument data manager providing all software and internal bus scheduling, ingestion of science data, distribution of commands, and performing science operations in real time.

Randomized controlled trial of moderate hypothermia versus deep hypothermia anesthesia on brain injury during Stanford A aortic dissection surgery.

PubMed

Sun, Xufang; Yang, Hua; Li, Xinyu; Wang, Yue; Zhang, Chuncheng; Song, Zhimin; Pan, Zhenxiang

2018-01-01

This study aimed to compare the effects of moderate versus deep hypothermia anesthesia for Stanford A aortic dissection surgery on brain injury. A total of 82 patients who would undergo Stanford A aortic dissection surgery were randomized into two groups: moderate hypothermia group (MH, n = 40, nasopharyngeal temperature 25 °C, and rectal temperature 28 °C) and deep hypothermia group (DH, n = 42, nasopharyngeal temperature 20 °C, and rectal temperature 25 °C). Different vascular replacement techniques including aortic root replacement, Bentall, and Wheat were used. The intraoperative and postoperative indicators of these patients were recorded. There were no differences in intraoperative and postoperative measures between MH and DH groups. The concentrations of neuron-specific enolase and S-100β increased with operation time, and were significantly lower in MH group than those in the DH group (P < 0.05). The occurrence rates of complications including chenosis, postoperative agitation, and neurological complications in MH group were significantly lower than in DH group. The recovery time, postoperative tube, and ICU intubation stay were significantly shorter in MH group than those in DH group (P < 0.05). There were no significant differences revealed in hospital stay and death rate. MH exhibited better cerebral protective effects, less complications, and shorter tube time than DH in surgery for Stanford A aortic dissection.

Time scale of dynamic heterogeneity in model ionic liquids and its relation to static length scale and charge distribution.

PubMed

Park, Sang-Won; Kim, Soree; Jung, YounJoon

2015-11-21

We study how dynamic heterogeneity in ionic liquids is affected by the length scale of structural relaxation and the ionic charge distribution by the molecular dynamics simulations performed on two differently charged models of ionic liquid and their uncharged counterpart. In one model of ionic liquid, the charge distribution in the cation is asymmetric, and in the other it is symmetric, while their neutral counterpart has no charge with the ions. It is found that all the models display heterogeneous dynamics, exhibiting subdiffusive dynamics and a nonexponential decay of structural relaxation. We investigate the lifetime of dynamic heterogeneity, τ(dh), in these systems by calculating the three-time correlation functions to find that τ(dh) has in general a power-law behavior with respect to the structural relaxation time, τ(α), i.e., τ(dh) ∝ τ(α)(ζ(dh)). Although the dynamics of the asymmetric-charge model is seemingly more heterogeneous than that of the symmetric-charge model, the exponent is found to be similar, ζ(dh) ≈ 1.2, for all the models studied in this work. The same scaling relation is found regardless of interactions, i.e., with or without Coulomb interaction, and it holds even when the length scale of structural relaxation is long enough to become the Fickian diffusion. This fact indicates that τ(dh) is a distinctive time scale from τ(α), and the dynamic heterogeneity is mainly affected by the short-range interaction and the molecular structure.

Plant Natural Products Calycosin and Gallic Acid Synergistically Attenuate Neutrophil Infiltration and Subsequent Injury in Isoproterenol-Induced Myocardial Infarction: A Possible Role for Leukotriene B4 12-Hydroxydehydrogenase?

PubMed Central

Cheng, Yuanyuan; Tse, Hung Fat; Le, X. Chris; Rong, Jianhui

2015-01-01

Leukotriene B4 12-hydroxydehydrogenase (LTB4DH) catalyzes the oxidation of proinflammatory LTB4 into less bioactive 12-oxo-LTB4. We recently discovered that LTB4DH was induced by two different natural products in combination. We previously isolated gallic acid from Radix Paeoniae through a bioactivity-guided fractionation procedure. The purpose of this study is to test the hypothesis that LTB4DH inducers may suppress neutrophil-mediated inflammation in myocardial infarction. We first isolated the active compound(s) from another plant, Radix Astragali, by the similar strategy. By evaluating LTB4DH induction, we identified calycosin and formononetin from Radix Astragali by HPLC-ESI-MS technique. We confirmed that gallic acid and commercial calycosin or formononetin could synergistically induce LTB4DH expression in HepG2 cells and human neutrophils. Moreover, calycosin and gallic acid attenuated the effects of LTB4 on the survival and chemotaxis of neutrophil cell culture. We further demonstrated that calycosin and gallic acid synergistically suppressed neutrophil infiltration and protected cardiac integrity in the isoproterenol-induced mice model of myocardial infarction. Calycosin and gallic acid dramatically suppressed isoproterenol-induced increase in myeloperoxidase (MPO) activity and malondialdehyde (MDA) level. Collectively, our results suggest that LTB4DH inducers (i.e., calycosin and gallic acid) may be a novel combined therapy for the treatment of neutrophil-mediated myocardial injury. PMID:26265982

A neuronal pathway that controls sperm ejection and storage in female Drosophila.

PubMed

Lee, Kang-Min; Daubnerová, Ivana; Isaac, R Elwyn; Zhang, Chen; Choi, Sekyu; Chung, Jongkyeong; Kim, Young-Joon

2015-03-16

In polyandrous females, sperm storage permits competition between sperm of different mates, and in some species females influence the relative fertilization success of competing sperm in favor of a preferred mate [1, 2]. In female Drosophila melanogaster, sperm competition is strongly influenced by the timing of sperm ejection from the uterus [3, 4]. Understanding how female behavior influences sperm competition requires knowledge of the neuronal mechanisms controlling sperm retention and storage, which is currently lacking. Here, we show that D. melanogaster females eject male ejaculates from the uterus 1-6 hr after mating with a stereotypic behavior regulated by a brain signaling pathway composed of diuretic hormone 44 (Dh44), a neuropeptide related to vertebrate corticotropin-releasing factor (CRF), and its receptor, Dh44R1. Suppression of Dh44 signals in the brain expedites sperm ejection from the uterus, resulting in marked reduction of sperm in the storage organs and decreased fecundity, whereas enhancement of Dh44 signals delays sperm expulsion. The Dh44 function was mapped to six neurons located in the pars intercerebralis of the brain together with a small subset of Dh44R1 neurons that express the sex-specific transcription factor doublesex. This study identifies a neuronal pathway by which females can control sperm retention and storage and provides new insight into how the female might exercise post-copulatory sexual selection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Drosophila DH31 Neuropeptide and PDF Receptor Regulate Night-Onset Temperature Preference

PubMed Central

Goda, Tadahiro; Tang, Xin; Umezaki, Yujiro; Chu, Michelle L.

2016-01-01

Body temperature exhibits rhythmic fluctuations over a 24 h period (Refinetti and Menaker, 1992) and decreases during the night, which is associated with sleep initiation (Gilbert et al., 2004; Kräuchi, 2007a,b). However, the underlying mechanism of this temperature decrease is largely unknown. We have previously shown that Drosophila exhibit a daily temperature preference rhythm (TPR), in which their preferred temperatures increase during the daytime and then decrease at the transition from day to night (night-onset) (Kaneko et al., 2012). Because Drosophila are small ectotherms, their body temperature is very close to that of the ambient temperature (Stevenson, 1985), suggesting that their TPR generates their body temperature rhythm. Here, we demonstrate that the neuropeptide diuretic hormone 31 (DH31) and pigment-dispersing factor receptor (PDFR) contribute to regulate the preferred temperature decrease at night-onset. We show that PDFR and tethered-DH31 expression in dorsal neurons 2 (DN2s) restore the preferred temperature decrease at night-onset, suggesting that DH31 acts on PDFR in DN2s. Notably, we previously showed that the molecular clock in DN2s is important for TPR. Although PDF (another ligand of PDFR) is a critical factor for locomotor activity rhythms, Pdf mutants exhibit normal preferred temperature decreases at night-onset. This suggests that DH31-PDFR signaling specifically regulates a preferred temperature decrease at night-onset. Thus, we propose that night-onset TPR and locomotor activity rhythms are differentially controlled not only by clock neurons but also by neuropeptide signaling in the brain. SIGNIFICANCE STATEMENT Body temperature rhythm (BTR) is fundamental for the maintenance of functions essential for homeostasis, such as generating metabolic energy and sleep. One major unsolved question is how body temperature decreases dramatically during the night. Previously, we demonstrated that a BTR-like mechanism, referred to as temperature preference rhythm (TPR), exists in Drosophila. Here, we demonstrate that the diuretic hormone 31 (DH31) neuropeptide and pigment-dispersing factor receptor (PDFR) regulate preferred temperature decreases at night-onset via dorsal neurons 2. This is the first in vivo evidence that DH31 could function as a ligand of PDFR. Although both DH31 and PDF are ligands of PDFR, we show that DH31 regulates night-onset TPR, but PDF does not, suggesting that night-onset TPR and locomotor activity rhythms are controlled by different neuropeptides via different clock cells. PMID:27852781

Drosophila DH31 Neuropeptide and PDF Receptor Regulate Night-Onset Temperature Preference.

PubMed

Goda, Tadahiro; Tang, Xin; Umezaki, Yujiro; Chu, Michelle L; Kunst, Michael; Nitabach, Michael N; Hamada, Fumika N

2016-11-16

Body temperature exhibits rhythmic fluctuations over a 24 h period (Refinetti and Menaker, 1992) and decreases during the night, which is associated with sleep initiation (Gilbert et al., 2004; Kräuchi, 2007a,b). However, the underlying mechanism of this temperature decrease is largely unknown. We have previously shown that Drosophila exhibit a daily temperature preference rhythm (TPR), in which their preferred temperatures increase during the daytime and then decrease at the transition from day to night (night-onset) (Kaneko et al., 2012). Because Drosophila are small ectotherms, their body temperature is very close to that of the ambient temperature (Stevenson, 1985), suggesting that their TPR generates their body temperature rhythm. Here, we demonstrate that the neuropeptide diuretic hormone 31 (DH31) and pigment-dispersing factor receptor (PDFR) contribute to regulate the preferred temperature decrease at night-onset. We show that PDFR and tethered-DH31 expression in dorsal neurons 2 (DN2s) restore the preferred temperature decrease at night-onset, suggesting that DH31 acts on PDFR in DN2s. Notably, we previously showed that the molecular clock in DN2s is important for TPR. Although PDF (another ligand of PDFR) is a critical factor for locomotor activity rhythms, Pdf mutants exhibit normal preferred temperature decreases at night-onset. This suggests that DH31-PDFR signaling specifically regulates a preferred temperature decrease at night-onset. Thus, we propose that night-onset TPR and locomotor activity rhythms are differentially controlled not only by clock neurons but also by neuropeptide signaling in the brain. Body temperature rhythm (BTR) is fundamental for the maintenance of functions essential for homeostasis, such as generating metabolic energy and sleep. One major unsolved question is how body temperature decreases dramatically during the night. Previously, we demonstrated that a BTR-like mechanism, referred to as temperature preference rhythm (TPR), exists in Drosophila Here, we demonstrate that the diuretic hormone 31 (DH31) neuropeptide and pigment-dispersing factor receptor (PDFR) regulate preferred temperature decreases at night-onset via dorsal neurons 2. This is the first in vivo evidence that DH31 could function as a ligand of PDFR. Although both DH31 and PDF are ligands of PDFR, we show that DH31 regulates night-onset TPR, but PDF does not, suggesting that night-onset TPR and locomotor activity rhythms are controlled by different neuropeptides via different clock cells. Copyright © 2016 the authors 0270-6474/16/3611739-16$15.00/0.

Genetic genealogy comes of age: perspectives on the use of deep-rooted pedigrees in human population genetics.

PubMed

Larmuseau, M H D; Van Geystelen, A; van Oven, M; Decorte, R

2013-04-01

In this article, we promote the implementation of extensive genealogical data in population genetic studies. Genealogical records can provide valuable information on the origin of DNA donors in a population genetic study, going beyond the commonly collected data such as residence, birthplace, language, and self-reported ethnicity. Recent studies demonstrated that extended genealogical data added to surname analysis can be crucial to detect signals of (past) population stratification and to interpret the population structure in a more objective manner. Moreover, when in-depth pedigree data are combined with haploid markers, it is even possible to disentangle signals of temporal differentiation within a population genetic structure during the last centuries. Obtaining genealogical data for all DNA donors in a population genetic study is a labor-intensive task but the vastly growing (genetic) genealogical databases, due to the broad interest of the public, are making this job more time-efficient if there is a guarantee for sufficient data quality. At the end, we discuss the advantages and pitfalls of using genealogy within sampling campaigns and we provide guidelines for future population genetic studies. Copyright © 2013 Wiley Periodicals, Inc.

Dorsal hippocampus inactivation impairs spontaneous recovery of Pavlovian magazine approach responding in rats.

PubMed

Campese, Vincent D; Delamater, Andrew R

2014-08-01

Destruction or inactivation of the dorsal hippocampus (DH) has been shown to eliminate the renewal of extinguished fear [1-4]. However, it has recently been reported that the contextual control of responding to extinguished appetitive stimuli is not disrupted when the DH is destroyed or inactivated prior to tests for renewal of Pavlovian conditioned magazine approach [5]. In the present study we extend the analysis of DH control of appetitive extinction learning to the spontaneous recovery of Pavlovian conditioned magazine approach responding. Subjects were trained to associate two separate stimuli with the delivery of food and had muscimol or vehicle infused into the DH prior to a single test-session for spontaneous recovery occurring immediately following extinction of one of these stimuli, but one week following extinction of the other. While vehicle treated subjects showed more recovery to the distally extinguished stimulus than the proximal one, muscimol treated subjects failed to show spontaneous recovery to either stimulus. This result suggests that, while the DH is not involved in the control of extinction by physical contexts [5], it may be involved when time is the gating factor controlling recovery of extinguished responding. Copyright © 2014 Elsevier B.V. All rights reserved.

Dorsal hippocampus inactivation impairs spontaneous recovery of Pavlovian magazine approach responding in rats

PubMed Central

Campese, Vincent D.; Delamater, Andrew R.

2014-01-01

Destruction or inactivation of the dorsal hippocampus (DH) has been shown to eliminate the renewal of extinguished fear [1–4]. However, it has recently been reported that the contextual control of responding to extinguished appetitive stimuli is not disrupted when the DH is destroyed or inactivated prior to tests for renewal of Pavlovian conditioned magazine approach [5]. In the present study we extend the analysis of DH control of appetitive extinction learning to the spontaneous recovery of Pavlovian conditioned magazine approach responding. Subjects were trained to associate two separate stimuli with the delivery of food and had muscimol or vehicle infused into the DH prior to a single test-session for spontaneous recovery occurring immediately following extinction of one of these stimuli, but one week following extinction of the other. While vehicle treated subjects showed more recovery to the distally extinguished stimulus than the proximal one, muscimol treated subjects failed to show spontaneous recovery to either stimulus. This result suggests that, while the DH is not involved in the control of extinction by physical contexts [5], it may be involved when time is the gating factor controlling recovery of extinguished responding. PMID:24742862

Communication: xDH double hybrid functionals can be qualitatively incorrect for non-equilibrium geometries: Dipole moment inversion and barriers to radical-radical association using XYG3 and XYGJ-OS

NASA Astrophysics Data System (ADS)

Hait, Diptarka; Head-Gordon, Martin

2018-05-01

Double hybrid (DH) density functionals are amongst the most accurate density functional approximations developed so far, largely due to the incorporation of correlation effects from unoccupied orbitals via second order perturbation theory (PT2). The xDH family of DH functionals calculate energy directly from orbitals optimized by a lower level approach like B3LYP, without self-consistent optimization. XYG3 and XYGJ-OS are two widely used xDH functionals that are known to be quite accurate at equilibrium geometries. Here, we show that the XYG3 and XYGJ-OS functionals can be ill behaved for stretched bonds well beyond the Coulson-Fischer point, predicting unphysical dipole moments and humps in potential energy curves for some simple systems like the hydrogen fluoride molecule. Numerical experiments and analysis show that these failures are not due to PT2. Instead, a large mismatch at stretched bond-lengths between the reference B3LYP orbitals and the optimized orbitals associated with the non-PT2 part of XYG3 leads to an unphysically large non-Hellman-Feynman contribution to first order properties like forces and electron densities.

The prediction of the building precision in the Laser Engineered Net Shaping process using advanced networks

NASA Astrophysics Data System (ADS)

Lu, Z. L.; Li, D. C.; Lu, B. H.; Zhang, A. F.; Zhu, G. X.; Pi, G.

2010-05-01

Laser Engineered Net Shaping (LENS) is an advanced manufacturing technology, but it is difficult to control the depositing height (DH) of the prototype because there are many technology parameters influencing the forming process. The effect of main parameters (laser power, scanning speed and powder feeding rate) on the DH of single track is firstly analyzed, and then it shows that there is the complex nonlinear intrinsic relationship between them. In order to predict the DH, the back propagation (BP) based network improved with Adaptive learning rate and Momentum coefficient (AM) algorithm, and the least square support vector machine (LS-SVM) network are both adopted. The mapping relationship between above parameters and the DH is constructed according to training samples collected by LENS experiments, and then their generalization ability, function-approximating ability and real-time are contrastively investigated. The results show that although the predicted result by the BP-AM approximates the experimental result, above performance index of the LS-SVM are better than those of the BP-AM. Finally, high-definition thin-walled parts of AISI316L are successfully fabricated. Hence, the LS-SVM network is more suitable for the prediction of the DH.

Up-regulation of tumor suppressor genes by exogenous dhC16-Cer contributes to its anti-cancer activity in primary effusion lymphoma.

PubMed

Cao, Yueyu; Qiao, Jing; Lin, Zhen; Zabaleta, Jovanny; Dai, Lu; Qin, Zhiqiang

2017-02-28

Primary effusion lymphoma (PEL) is a rare and highly aggressive B-cell malignancy with Kaposi's sarcoma-associated herpesvirus (KSHV) infection, while lack of effective therapies. Our recent data indicated that targeting the sphingolipid metabolism by either sphingosine kinase inhibitor or exogenous ceramide species induces PEL cell apoptosis and suppresses tumor progression in vivo. However, the underlying mechanisms for these exogenous ceramides "killing" PEL cells remain largely unknown. Based on the microarray analysis, we found that exogenous dhC16-Cer treatment affected the expression of many cellular genes with important functions within PEL cells such as regulation of cell cycle, cell survival/proliferation, and apoptosis/anti-apoptosis. Interestingly, we found that a subset of tumor suppressor genes (TSGs) was up-regulated from dhC16-Cer treated PEL cells. One of these elevated TSGs, Thrombospondin-1 (THBS1) was required for dhC16-Cer induced PEL cell cycle arrest. Moreover, dhC16-Cer up-regulation of THBS1 was through the suppression of multiple KSHV microRNAs expression. Our data demonstrate that exogenous ceramides display anti-cancer activities for PEL through regulation of both host and oncogenic virus factors.

Detection of QTLs for seedling characteristics in barley (Hordeum vulgare L.) grown under hydroponic culture condition.

PubMed

Wang, Qifei; Sun, Genlou; Ren, Xifeng; Wang, Jibin; Du, Binbin; Li, Chengdao; Sun, Dongfa

2017-11-07

Seedling characteristics play significant roles in the growth and development of barley (Hordeum vulgare L.), including stable stand establishment, water and nutrients uptake, biotic resistance and abiotic stresses, and can influence yield and quality. However, the genetic mechanisms underlying seedling characteristics in barley are largely unknown and little research has been done. In the present work, 21 seedling-related characteristics are assessed in a barley double haploid (DH) population, grown under hydroponic conditions. Of them, leaf age (LAG), shoot height (SH), maximum root length (MRL), main root number (MRN) and seedling fresh weight (SFW) were investigated at the 13th, 20th, 27th, and 34th day after germination. The objectives were to identify quantitative trait loci (QTLs) underlying these seedling characteristics using a high-density linkage map and to reveal the QTL expression pattern by comparing the QTLs among four different seedling growth stages. A total of 70 QTLs were distributed over all chromosomes except 4H, and, individually, accounted for 5.01%-77.78% of phenotypic variation. Out of the 70 detected QTLs, 23 showed a major effect on 14 seedling-related characteristics. Ten co-localized chromosomal regions on 2H (five regions), 3H (two regions) and 7H (three regions) involved 39 QTLs (55.71%), each simultaneously influenced more than one trait. Meanwhile, 9 co-localized genomic regions involving 22 QTLs for five seedling characteristics (LAG, SH, MRL, MRN and SFW) at the 13th, 20th, 27th and 34th day-old seedling were common for two or more growth stages of seedling. QTL in the vicinity of Vrs1 locus on chromosome 2H with the favorable alleles from Huadamai 6 was found to have the largest main effects on multiple seedling-related traits. Six QTL cluster regions associated with 16 seedling-related characteristics were observed on chromosome 2H, 3H and 7H. The majority of the 29 regions identified for five seedling characteristics were selectively expressed at different developmental stages. The genetic effects of 9 consecutive expression regions displayed different developmental influences at different developmental stages. These findings enhanced our understanding of a genetic basis underlying seedling characteristics in barley. Some QTLs detected here could be used for marker-assisted selection (MAS) in barley breeding.

Impact of Next Generation District Heating Systems on Distribution Network Heat Losses: A Case Study Approach

NASA Astrophysics Data System (ADS)

Li, Yu; Rezgui, Yacine

2018-01-01

District heating (DH) is a promising energy pathway to alleviate environmental negative impacts induced by fossil fuels. Improving the performance of DH systems is one of the major challenges facing its wide adoption. This paper discusses the heat losses of the next generation DH based on the constructed Simulink model. Results show that lower distribution temperature and advanced insulation technology greatly reduce network heat losses. Also, the network heat loss can be further minimized by a reduction of heat demand in buildings.

KSC-2009-2516

NASA Image and Video Library

2009-04-02

CAPE CANAVERAL, Fla. – In the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, technicians look over the Science Instrument Command and Data Handling Unit, or SIC&DH. The SIC&DH will be installed on the Multi-Use Lightweight Equipment Carrier in the facility. The SIC&DH will be installed on the Hubble Space Telescope during space shuttle Atlantis' STS-125 mission. This unit will replace the one that suffered a failure aboard the orbiting telescope on Sept. 27, 2008. Atlantis is targeted for launch on May 12. Photo credit: NASA/Dimitri Gerondidakis

The D/H ratio in water from Halley

NASA Technical Reports Server (NTRS)

Eberhardt, P.; Dolder, U.; Schulte, W.; Krankowsky, D.; Laemmerzahl, P.; Hoffman, J. H.; Hodges, R. R.; Berthelier, J. J.; Illiano, J. M.

1986-01-01

The neutral gas mass spectrometer on Giotto made neutral and ion composition measurements with a high mass resolution. Evaluation of the ion data within the contact surface gives a D/H ratio in water from Halley between 0.00006 and 0.00048. While this ratio is definitely not compatible with the D/H in molecular hydrogen of the protosolar nebula or the Jovian and Saturnian atmospheres, it is in the range observed for hydrogen in solar system objects which acquired their hydrogen as part of volatile molecules, e.g., as ices.

Increase of transcription factor EB (TFEB) and lysosomes in rat DRG neurons and their transportation to the central nerve terminal in dorsal horn after nerve injury.

PubMed

Jung, J; Uesugi, N; Jeong, N Y; Park, B S; Konishi, H; Kiyama, H

2016-01-28

In the spinal dorsal horn (DH), nerve injury activates microglia and induces neuropathic pain. Several studies clarified an involvement of adenosine triphosphate (ATP) in the microglial activation. However, the origin of ATP together with the release mechanism is unclear. Recent in vitro study revealed that an ATP marker, quinacrine, in lysosomes was released from neurite terminal of dorsal root ganglion (DRG) neurons to extracellular space via lysosomal exocytosis. Here, we demonstrate a possibility that the lysosomal ingredient including ATP released from DRG neurons by lysosomal-exocytosis is an additional source of the glial activation in DH after nerve injury. After rat L5 spinal nerve ligation (SNL), mRNA for transcription factor EB (TFEB), a transcription factor controlling lysosomal activation and exocytosis, was induced in the DRG. Simultaneously both lysosomal protein, LAMP1- and vesicular nuclear transporter (VNUT)-positive vesicles were increased in L5 DRG neurons and ipsilateral DH. The quinacrine staining in DH was increased and co-localized with LAMP1 immunoreactivity after nerve injury. In DH, LAMP1-positive vesicles were also co-localized with a peripheral nerve marker, Isolectin B4 (IB4) lectin. Injection of the adenovirus encoding mCherry-LAMP1 into DRG showed that mCherry-positive lysosomes are transported to the central nerve terminal in DH. These findings suggest that activation of lysosome synthesis including ATP packaging in DRG, the central transportation of the lysosome, and subsequent its exocytosis from the central nerve terminal of DRG neurons in response to nerve injury could be a partial mechanism for activation of microglia in DH. This lysosome-mediated microglia activation mechanism may provide another clue to control nociception and pain. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Dual function of Lactobacillus kefiri DH5 in preventing high-fat-diet-induced obesity: direct reduction of cholesterol and upregulation of PPAR-α in adipose tissue.

PubMed

Kim, Dong-Hyeon; Jeong, Dana; Kang, Il-Byeong; Kim, Hyunsook; Song, Kwang-Young; Seo, Kun-Ho

2017-11-01

Kefir consumption inhibits the development of obesity and non-alcoholic fatty liver disease (NALFD) in mice fed 60% high-fat diet (HFD). To identify the key contributor of this effect, we isolated lactic acid bacteria (LAB) from kefir and examined their anti-obesity properties from in vitro screening and in vivo validation. Thirteen kefir LAB isolates were subjected to survivability test using artificial gastrointestinal environment and cholesterol-reducing assay. Lactobacillus kefiri DH5 showed 100% survivability in gastrointestinal environments and reduced 51.6% of cholesterol; thus, this strain was selected for in vivo experiment. Compared to the HFD-saline group, the HFD-DH5 group showed significantly lower body weight (34.68 versus 31.10 g; p < 0.001), epididymal adipose tissue weight (1.39 versus 1.05 g; p < 0.001), blood triglyceride (38.2 versus 31.0 mg/dL; p < 0.01) and LDL-cholesterol levels (19.4 versus 15.7 mg/dL; p < 0.01). In addition, L. kefiri DH5 administration significantly modulated gut microbiota of HFD-fed mice. The hepatic steatosis was significantly milder (Lesion score, 2.1 versus 1.2; p < 0.001) and adipocyte diameter was significantly smaller (65.1 versus 42.2 μm; p < 0.001) in the HFD-DH5 group. L. kefiri DH5 upregulated PPAR-α, FABP4, and CPT1 expression in the epididymal adipose tissues (2.29-, 1.77-, and 2.05-fold change, respectively), suggesting a reduction in adiposity by stimulating fatty acid oxidation. L. kefiri DH5 exerts anti-obesity effects by direct reduction of cholesterol in the lumen and upregulation of PPAR-α gene in adipose tissues. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Avulsion of the direct head of rectus femoris following arthroscopic subspine impingement resection: a case report

PubMed Central

Devitt, Brian M.; Smith, Bjorn; Stapf, Robert; O’Donnell, John M.

2016-01-01

Arthroscopic resection of the anterior inferior iliac spine (AIIS) for subspine impingement has become a relatively common procedure. The AIIS is the origin of the direct head of rectus femoris (dhRF). Previous studies have reported that removal of the contributing portion of the AIIS causing impingement is unlikely to weaken the attachment of the dhRF. The purpose of this article is to report a case of avulsion of the dhRF, following revision hip arthroscopy for the treatment of subspine impingement. A 23-year-old professional footballer underwent revision left hip arthroscopy for the treatment of subspine impingement. 5-mm of bone was resected inferior to the AIIS. Two-weeks post-operatively, he presented with sudden onset, severe left anterior thigh pain following a fall and hyperextension of his left hip. The patient felt a pop over the anterior aspect of his hip. He noticed immediate swelling, severe pain and stiffness. Examination revealed diffuse swelling, 4/5-power on straight-leg-raise, focal tenderness over the AIIS but no palpable gap. MRI confirmed the clinical suspicion of a dhRF avulsion. Given the minimal loss of power and the lack of significant retraction, the patient was treated conservatively. He was instructed to avoid excessive hip extension. He returned to full participation at 3-months. This article highlights a case of avulsion of the dhRF due to a hyperextension injury of the hip following arthroscopic resection of subspinal impingement, a previously unreported complication. Resection of soft and bone from the AIIS may weaken the insertion of the dhRF. Care should be taken during post-operative rehabilitation to avoid trauma and excessive forces on the dhRF tendon, which may lead to rupture. Rehabilitation should be focused on range of motion of the hip. PMID:27026819

Avulsion of the direct head of rectus femoris following arthroscopic subspine impingement resection: a case report.

PubMed

Devitt, Brian M; Smith, Bjorn; Stapf, Robert; O'Donnell, John M

2016-04-01

Arthroscopic resection of the anterior inferior iliac spine (AIIS) for subspine impingement has become a relatively common procedure. The AIIS is the origin of the direct head of rectus femoris (dhRF). Previous studies have reported that removal of the contributing portion of the AIIS causing impingement is unlikely to weaken the attachment of the dhRF. The purpose of this article is to report a case of avulsion of the dhRF, following revision hip arthroscopy for the treatment of subspine impingement. A 23-year-old professional footballer underwent revision left hip arthroscopy for the treatment of subspine impingement. 5-mm of bone was resected inferior to the AIIS. Two-weeks post-operatively, he presented with sudden onset, severe left anterior thigh pain following a fall and hyperextension of his left hip. The patient felt a pop over the anterior aspect of his hip. He noticed immediate swelling, severe pain and stiffness. Examination revealed diffuse swelling, 4/5-power on straight-leg-raise, focal tenderness over the AIIS but no palpable gap. MRI confirmed the clinical suspicion of a dhRF avulsion. Given the minimal loss of power and the lack of significant retraction, the patient was treated conservatively. He was instructed to avoid excessive hip extension. He returned to full participation at 3-months. This article highlights a case of avulsion of the dhRF due to a hyperextension injury of the hip following arthroscopic resection of subspinal impingement, a previously unreported complication. Resection of soft and bone from the AIIS may weaken the insertion of the dhRF. Care should be taken during post-operative rehabilitation to avoid trauma and excessive forces on the dhRF tendon, which may lead to rupture. Rehabilitation should be focused on range of motion of the hip.

D/H Ratios in Lipids as a Tool to Elucidate Microbial Metabolism

NASA Astrophysics Data System (ADS)

Wijker, R. S.; Sessions, A. L.

2015-12-01

Large D/H fractionations have been observed in the lipids and growth water of most organisms studied today. These fractionations have generally been assumed to be constant across most biota because they originate solely from isotope effects imposed by the highly conserved lipid biosynthetic pathway. Recent data is illustrating this conclusion as incomplete. Lipids from field and laboratory samples exhibit huge variations in D/H fractionation. In environmental samples, lipids vary in δD by up to 300 ‰ and in laboratory cultures the documented variation is up to 500 ‰ within the same organism. Remarkably, the isotope fractionation appears to be correlated with the type of metabolism employed by the host organism. However, the underlying biochemical mechanisms leading to these isotopic variations are not yet fully understood. Because the largest proportion of H-bound C in fatty acids is derived directly from NADPH during biosynthesis, the original hypothesis was that large differences in the isotopic composition of NADPH, generated by different central metabolic pathways, were the primary source of D/H variation in lipids. However, recent observations indicate that this cannot be the whole story and lead us to the conclusion that additional processes must affect the isotope composition of NADPH. These processes may include the isotopic exchange of NADPH with water as well as fractionation of NADPH by transhydrogenases, interconverting NADH to NADPH by exhibiting large isotope effects. In this project, our objective is to ascertain whether D/H fractionation and these biochemical processes are correlated. We investigate correlations between cellular NADPH/NADP+ as well as NADH/NAD+ pool sizes and the D/H fractionation in a set of different microorganisms and will present the first trends here. Our results will contribute to a more comprehensive understanding of the basic biological regulations over D/H fractionation and potentially enables their use as tracers and proxies across earth and biological sciences.

D/H Ratios in Lipids as a Tool to Elucidate Microbial Metabolism

NASA Astrophysics Data System (ADS)

Wijker, Reto S.; Sessions, Alex L.

2016-04-01

Large D/H fractionations have been observed in the lipids and growth water of most organisms studied today. These fractionations have generally been assumed to be constant across most biota because they originate solely from isotope effects imposed by the highly conserved lipid biosynthetic pathway. Recent data is illustrating this conclusion as incomplete. Lipids from field and laboratory samples exhibit huge variations in D/H fractionation. In environmental samples, lipids vary in δD by up to 300 ‰ and in laboratory cultures the documented variation is up to 500 ‰ within the same organism. Remarkably, the isotope fractionation appears to be correlated with the type of metabolism employed by the host organism. However, the underlying biochemical mechanisms leading to these isotopic variations are not yet fully understood. Because the largest proportion of H-bound C in fatty acids is derived directly from NADPH during biosynthesis, the original hypothesis was that large differences in the isotopic composition of NADPH, generated by different central metabolic pathways, were the primary source of D/H variation in lipids. However, recent observations indicate that this cannot be the whole story and lead us to the conclusion that additional processes must affect the isotope composition of NADPH. These processes may include the isotopic exchange of NADPH with water as well as fractionation of NADPH by transhydrogenases, interconverting NADH to NADPH by exhibiting large isotope effects. In this project, our objective is to ascertain whether D/H fractionation and these biochemical processes are correlated. We investigate correlations between cellular NADPH/NADP+ as well as NADH/NAD+ pool sizes and the D/H fractionation in a set of different microorganisms and will present the trends here. Our results will contribute to a more comprehensive understanding of the basic biological regulations over D/H fractionation and potentially enables their use as tracers and proxies across earth and biological sciences.

MR elastography measurement of the effect of passive warmup prior to eccentric exercise on thigh muscle mechanical properties

PubMed Central

Kennedy, Paul; Macgregor, Lewis J.; Barnhill, Eric; Johnson, Curtis L.; Perrins, Michael; Hunter, Angus; Brown, Colin; van Beek, Edwin J.R.

2017-01-01

Purpose To investigate the effect of warmup by application of the thermal agent Deep Heat (DH) on muscle mechanical properties using magnetic resonance elastography (MRE) at 3T before and after exercise‐induced muscle damage (EIMD). Materials and Methods Twenty male participants performed an individualized protocol designed to induce EIMD in the quadriceps. DH was applied to the thigh in 50% of the participants before exercise. MRE, T 2‐weighted MRI, maximal voluntary contraction (MVC), creatine kinase (CK) concentration, and muscle soreness were measured before and after the protocol to assess EIMD effects. Five participants were excluded: four having not experienced EIMD and one due to incidental findings. Results Total workload performed during the EIMD protocol was greater in the DH group than the control group (P < 0.03), despite no significant differences in baseline MVC (P = 0.23). Shear stiffness |G*| increased in the rectus femoris (RF) muscle in both groups (P < 0.03); however, DH was not a significant between‐group factor (P =  0.15). MVC values returned to baseline faster in the DH group (5 days) than the control group (7 days). Participants who displayed hyperintensity on T 2‐weighted images had a greater stiffness increase following damage than those without: RF; 0.61 kPa vs. 0.15 kPa, P < 0.006, vastus intermedius; 0.34 kPa vs. 0.03 kPa, P = 0.06. Conclusion EIMD produces increased muscle stiffness as measured by MRE, with the change in |G*| significantly increased when T 2 hyperintensity was present. DH did not affect CK concentration or soreness; however, DH participants produced greater workload during the EIMD protocol and exhibited accelerated MVC recovery. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1115–1127. PMID:28218814

moxFG region encodes four polypeptides in the methanol-oxidizing bacterium Methylobacterium sp. strain AM1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, D.J.; Lidstrom, M.E.

The polypeptides encoded by a putative methanol oxidation (mox) operon of Methylobacterium sp. strain AM1 were expressed in Escherichia coli, using a coupled in vivo T7 RNA polymerase/promoter gene expression system. Two mox genes had been previously mapped to this region: moxF, the gene encoding the methanol dehydrogenase (MeDH) polypeptide; and moxG, a gene believed to encode a soluble type c cytochrome, cytochrome c/sub L/. In this study, four polypeptides of M/sub r/, 60,000, 30,000, 20,000, and 12,000 were found to be encoded by the moxFG region and were tentatively designated moxF, -J, -G, and -I, respectively. The arrangement ofmore » the genes (5' to 3') was found to be moxFJGI. The identities of three of the four polypeptides were determined by protein immunoblot analysis. The product of moxF, the M/sub r/-60,000 polypeptide, was confirmed to be the MeDH polypeptide. The product of moxG, the M/sub r/-20,000 polypeptide, was identified as mature cytochrome c/sub L/, and the product of moxI, the M/sub r/-12,000 polypeptide, was identified as a MeDH-associated polypeptide that copurifies with the holoenzyme. The identity of the M/sub r/-30,000 polypeptide (the moxJ gene product) could not be determined. The function of the M/sub r/-12,000 MeDH-associated polypeptide is not yet clear. However, it is not present in mutants that lack the M/sub r/-60,000 MeDH subunit, and it appears that the stability of the MeDH-associated polypeptide is dependent on the presence of the M/sub r/-60,000 MeDH polypeptide. Our data suggest that both the M/sub r/-30,000 and -12,000 polypeptides are involved in methanol oxidation, which would bring to 12 the number of mox genes in Methylobacterium sp. strain AM1.« less

Reaction mechanism of sterol hydroxylation by steroid C25 dehydrogenase - Homology model, reactivity and isoenzymatic diversity.

PubMed

Rugor, Agnieszka; Wójcik-Augustyn, Anna; Niedzialkowska, Ewa; Mordalski, Stefan; Staroń, Jakub; Bojarski, Andrzej; Szaleniec, Maciej

2017-08-01

Steroid C25 dehydrogenase (S25DH) is a molybdenum-containing oxidoreductase isolated from the anaerobic Sterolibacterium denitrificans Chol-1S. S25DH is classified as 'EBDH-like' enzyme (EBDH, ethylbenzene dehydrogenase) and catalyzes the introduction of an OH group to the C25 atom of a sterol aliphatic side-chain. Due to its regioselectivity, S25DH is proposed as a catalyst in production of pharmaceuticals: calcifediol or 25-hydroxycholesterol. The aim of presented research was to obtain structural model of catalytic subunit α and investigate the reaction mechanism of the O 2 -independent tertiary carbon atom activation. Based on homology modeling and theoretical calculations, a S25DH α subunit model was for the first time characterized and compared to other S25DH-like isoforms. The molecular dynamics simulations of the enzyme-substrate complexes revealed two stable binding modes of a substrate, which are stabilized predominantly by van der Waals forces in the hydrophobic substrate channel. However, H-bond interactions involving polar residues with C3=O/C3-OH in the steroid ring appear to be responsible for positioning the substrate. These results may explain the experimental kinetic results which showed that 3-ketosterols are hydroxylated 5-10-fold faster than 3-hydroxysterols. The reaction mechanism was studied using QM:MM and QM-only cluster models. The postulated mechanism involves homolytic CH cleavage by the MoO ligand, giving rise to a radical intermediate with product obtained in an OH rebound process. The hypothesis was supported by kinetic isotopic effect (KIE) experiments involving 25,26,26,26-[ 2 H]-cholesterol (4.5) and the theoretically predicted intrinsic KIE (7.0-7.2). Finally, we have demonstrated that the recombinant S25DH-like isoform catalyzes the same reaction as S25DH. Copyright © 2017 Elsevier Inc. All rights reserved.

Multichannel Analysis of Surface Waves and Down-Hole Tests in the Archeological "Palatine Hill" Area (Rome, Italy): Evaluation and Influence of 2D Effects on the Shear Wave Velocity

NASA Astrophysics Data System (ADS)

Di Fiore, V.; Cavuoto, G.; Tarallo, D.; Punzo, M.; Evangelista, L.

2016-05-01

A joint analysis of down-hole (DH) and multichannel analysis of surface waves (MASW) measurements offers a complete evaluation of shear wave velocity profiles, especially for sites where a strong lateral variability is expected, such as archeological sites. In this complex stratigraphic setting, the high "subsoil anisotropy" (i.e., sharp lithological changes due to the presence of anthropogenic backfill deposits and/or buried man-made structures) implies a different role for DH and MASW tests. This paper discusses some results of a broad experimental program conducted on the Palatine Hill, one of the most ancient areas of the city of Rome (Italy). The experiments were part of a project on seismic microzoning and consisted of 20 MASW and 11 DH tests. The main objective of this study was to examine the difficulties related to the interpretation of the DH and MASW tests and the reliability limits inherent in the application of the noninvasive method in complex stratigraphic settings. As is well known, DH tests provide good determinations of shear wave velocities (Vs) for different lithologies and man-made materials, whereas MASW tests provide average values for the subsoil volume investigated. The data obtained from each method with blind tests were compared and were correlated to site-specific subsurface conditions, including lateral variability. Differences between punctual (DH) and global (MASW) Vs measurements are discussed, quantifying the errors by synthetic comparison and by site response analyses. This study demonstrates that, for archeological sites, VS profiles obtained from the DH and MASW methods differ by more than 15 %. However, the local site effect showed comparable results in terms of natural frequencies, whereas the resolution of the inverted shear wave velocity was influenced by the fundamental mode of propagation.

Effects of hydrolysis on solid-state relaxation and stickiness behavior of sodium caseinate-lactose powders.

PubMed

Mounsey, J S; Hogan, S A; Murray, B A; O'Callaghan, D J

2012-05-01

Hydrolyzed or nonhydrolyzed sodium caseinate-lactose dispersions were spray dried, at a protein: lactose ratio of 0.5, to examine the effects of protein hydrolysis on relaxation behavior and stickiness of model powders. Sodium caseinate (NC) used included a nonhydrolyzed control (DH 0) and 2 hydrolyzed variants (DH 8.3 and DH 15), where DH = degree of hydrolysis (%). Prior to spray drying, apparent viscosities of liquid feeds (at 70°C) at a shear rate of 20/s were 37.6, 3.14, and 3.19 mPa·s, respectively, for DH 0, DH 8, and DH 15 dispersions. Powders containing hydrolyzed casein were more susceptible to sticking than those containing intact NC. The former had also lower bulk densities and powder particle sizes. Scanning electron microscopy showed that hydrolyzed powders had thinner particle walls and were more friable than powders containing intact NC. Secondary structure of caseinates, determined by Fourier transform infrared spectroscopy, was affected by the relative humidity of storage and the presence of lactose as co-solvent rather than its physical state. Glass transition temperatures and lactose crystallization temperatures, determined by differential scanning calorimetry were not affected by caseinate hydrolysis, although the effects of protein hydrolysis on glass-rubber transitions (T(gr)) could be determined by thermo-mechanical analysis. Powders containing hydrolyzed NC had lower T(gr) values (~30°C) following storage at a higher subcrystallization relative humidity (33%) compared with powder with nonhydrolyzed NC (T(gr) value of ~40°C), an effect that reflects more extensive plasticization of powder matrices by moisture. Results support that sodium caseinate-lactose interactions were weak but that relaxation behavior, as determined by the susceptibility of powder to sticking, was affected by hydrolysis of sodium caseinate. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Signatures of host specialization and a recent transposable element burst in the dynamic one-speed genome of the fungal barley powdery mildew pathogen.

PubMed

Frantzeskakis, Lamprinos; Kracher, Barbara; Kusch, Stefan; Yoshikawa-Maekawa, Makoto; Bauer, Saskia; Pedersen, Carsten; Spanu, Pietro D; Maekawa, Takaki; Schulze-Lefert, Paul; Panstruga, Ralph

2018-05-22

Powdery mildews are biotrophic pathogenic fungi infecting a number of economically important plants. The grass powdery mildew, Blumeria graminis, has become a model organism to study host specialization of obligate biotrophic fungal pathogens. We resolved the large-scale genomic architecture of B. graminis forma specialis hordei (Bgh) to explore the potential influence of its genome organization on the co-evolutionary process with its host plant, barley (Hordeum vulgare). The near-chromosome level assemblies of the Bgh reference isolate DH14 and one of the most diversified isolates, RACE1, enabled a comparative analysis of these haploid genomes, which are highly enriched with transposable elements (TEs). We found largely retained genome synteny and gene repertoires, yet detected copy number variation (CNV) of secretion signal peptide-containing protein-coding genes (SPs) and locally disrupted synteny blocks. Genes coding for sequence-related SPs are often locally clustered, but neither the SPs nor the TEs reside preferentially in genomic regions with unique features. Extended comparative analysis with different host-specific B. graminis formae speciales revealed the existence of a core suite of SPs, but also isolate-specific SP sets as well as congruence of SP CNV and phylogenetic relationship. We further detected evidence for a recent, lineage-specific expansion of TEs in the Bgh genome. The characteristics of the Bgh genome (largely retained synteny, CNV of SP genes, recently proliferated TEs and a lack of significant compartmentalization) are consistent with a "one-speed" genome that differs in its architecture and (co-)evolutionary pattern from the "two-speed" genomes reported for several other filamentous phytopathogens.

Brewing characteristics of haploid strains isolated from sake yeast Kyokai No. 7.

PubMed

Katou, Taku; Kitagaki, Hiroshi; Akao, Takeshi; Shimoi, Hitoshi

2008-11-01

Sake yeast exhibit various characteristics that make them more suitable for sake brewing compared to other yeast strains. Since sake yeast strains are Saccharomyces cerevisiae heterothallic diploid strains, it is likely that they have heterozygous alleles on homologous chromosomes (heterozygosity) due to spontaneous mutations. If this is the case, segregation of phenotypic traits in haploid strains after sporulation and concomitant meiosis of sake yeast strains would be expected to occur. To examine this hypothesis, we isolated 100 haploid strains from Kyokai No. 7 (K7), a typical sake yeast strain in Japan, and compared their brewing characteristics in small-scale sake-brewing tests. Analyses of the resultant sake samples showed a smooth and continuous distribution of analytical values for brewing characteristics, suggesting that K7 has multiple heterozygosities that affect brewing characteristics and that these heterozygous alleles do segregate after sporulation. Correlation and principal component analyses suggested that the analytical parameters could be classified into two groups, indicating fermentation ability and sake flavour. (c) 2008 John Wiley & Sons, Ltd.

Identification of Spen as a Crucial Factor for Xist Function through Forward Genetic Screening in Haploid Embryonic Stem Cells

PubMed Central

Monfort, Asun; Di Minin, Giulio; Postlmayr, Andreas; Freimann, Remo; Arieti, Fabiana; Thore, Stéphane; Wutz, Anton

2015-01-01

Summary In mammals, the noncoding Xist RNA triggers transcriptional silencing of one of the two X chromosomes in female cells. Here, we report a genetic screen for silencing factors in X chromosome inactivation using haploid mouse embryonic stem cells (ESCs) that carry an engineered selectable reporter system. This system was able to identify several candidate factors that are genetically required for chromosomal repression by Xist. Among the list of candidates, we identify the RNA-binding protein Spen, the homolog of split ends. Independent validation through gene deletion in ESCs confirms that Spen is required for gene repression by Xist. However, Spen is not required for Xist RNA localization and the recruitment of chromatin modifications, including Polycomb protein Ezh2. The identification of Spen opens avenues for further investigation into the gene-silencing pathway of Xist and shows the usefulness of haploid ESCs for genetic screening of epigenetic pathways. PMID:26190100

Strain improvement of chymosin-producing strains of Aspergillus niger var. awamori using parasexual recombination.

PubMed

Bodie, E A; Armstrong, G L; Dunn-Coleman, N S

1994-05-01

Parasexual recombination was used to obtain improved chymosin-producing strains and to perform genetic analysis on existing strains. Chlorate resistance was used to select for a variety of spontaneous nitrate assimilation pathway mutations in strains previously improved for chymosin production using classical strain improvement methods including mutation and screening, and selection for 2-deoxyglucose resistance (dgr). Diploids of these improved strains were generated via parasexual recombination and were isolated on selective media by complementation of nitrate assimilation mutations. A preliminary genetic analysis of diploid and haploid segregants indicated that the dgr trait, resulting in overexpression of chymosin, was recessive. Also, mutations in two different dgr genes resulted in an increased level of chymosin production. When these mutations were combined via parasexual recombination, the resulting haploid segregants produced about 15% more chymosin than either parental strain. CHEF gel electrophoresis was used to determine the chromosomal location of the integrated chymosin DNA sequences, and to verify diploidy in one case where the chromosome composition of two haploid parents differed.

Digital Holography and 3D Imaging: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America A.

PubMed

Kang, Hoonjong; Lee, Byoungho; Kozacki, Tomasz; Picart, Pascal; Situ, Guohai

2018-01-01

The OSA Topical Meeting on Digital Holography and 3D Imaging (DH) was held 29 May to 1 June 2017 in Jeju Island, South Korea. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. This year, AO and the Journal of the Optical Society of America A (JOSA A) jointly decided to have one such feature issue in each journal. This feature issue includes 33 papers in AO and 9 in JOSA A and covers a large range of topics, reflecting the rapidly expanding techniques and applications of digital holography and 3D imaging. The upcoming DH meeting (DH 2018) will be held 25-28 June 2018 in Orlando, Florida, USA, as part of the OSA Imaging and Applied Optics Congress.

Digital Holography and 3D Imaging: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America A.

PubMed

Kang, Hoonjong; Lee, Byoungho; Kozacki, Tomasz; Picart, Pascal; Situ, Guohai

2018-01-01

The OSA Topical Meeting on Digital Holography and 3D Imaging (DH) was held 29 May to 1 June 2017 on Jeju Island, South Korea. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. This year, AO and the Journal of the Optical Society of America A (JOSA A) jointly decided to have one such feature issue in each journal. This feature issue includes 33 papers in AO and 9 in JOSA A and covers a large range of topics, reflecting the rapidly expanding techniques and applications of digital holography and 3D imaging. The upcoming DH meeting (DH 2018) will be held 25-28 June 2018 in Orlando, Florida, as part of the OSA Imaging and Applied Optics Congress.

ABA and ABC renewal of conditioned magazine approach are not impaired by dorsal hippocampus inactivation or lesions.

PubMed

Campese, Vincent; Delamater, Andrew R

2013-07-01

Three experiments investigated the role of the dorsal hippocampus (DH) in renewal of conditioned and then extinguished magazine approach responding in rats. Experiments 1 and 2 found no effect of muscimol inactivation of the DH during testing on ABA and ABC renewal, respectively. However, subjects from these studies were subsequently found to be impaired on a delayed non-matching-to-place task following muscimol but not saline infusions. Experiment 3 found no effects of post-training excitotoxic lesions of the DH on ABA and ABC renewal. Lesioned subjects were, however, impaired on the delayed non-matching-to-place task compared to control subjects. These findings suggest that the DH may not play a similar role in Pavlovian extinction in appetitive learning tasks as has previously been reported in aversive learning. Copyright © 2013 Elsevier B.V. All rights reserved.

The Dorothy I. Height Center for Health Equity and Evaluation Research (CHEER)

DTIC Science & Technology

2012-10-01

requested and subsequently awarded a renewal DH-CHEER PROGRESS REPORT (W81XWH-11-1-0824): 9/30/11 – 9/29/12 9 proposal to expand and evaluate the...than children of the same ethnicity and age living in the same region, but not near any Superfund sites or agricultural fields. In specific aim 1...population of Hispanic elderly. Five federal agencies - Administration on Aging (AoA), the Agency for Healthcare Research and Quality (AHRQ), the

The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.

PubMed

Baniaga, Anthony E; Arrigo, Nils; Barker, Michael S

2016-06-03

The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Characters that differ between diploid and haploid honey bee (Apis mellifera) drones.

PubMed

Herrmann, Matthias; Trenzcek, Tina; Fahrenhorst, Hartmut; Engels, Wolf

2005-12-30

Diploid males have long been considered a curiosity contradictory to the haplo-diploid mode of sex determination in the Hymenoptera. In Apis mellifera, 'false' diploid male larvae are eliminated by worker cannibalism immediately after hatching. A 'cannibalism substance' produced by diploid drone larvae to induce worker-assisted suicide has been hypothesized, but it has never been detected. Diploid drones are only removed some hours after hatching. Older larvae are evidently not regarded as 'false males' and instead are regularly nursed by the brood-attending worker bees. As the pheromonal cues presumably are located on the surface of newly hatched bee larvae, we extracted the cuticular secretions and analyzed their chemical composition by gas chromatograph-mass spectrometry (GC-MS) analyses. Larvae were sexed and then reared in vitro for up to three days. The GC-MS pattern that was obtained, with alkanes as the major compounds, was compared between diploid and haploid drone larvae. We also examined some physical parameters of adult drones. There was no difference between diploid and haploid males in their weight at the day of emergence. The diploid adult drones had fewer wing hooks and smaller testes. The sperm DNA content was 0.30 and 0.15 pg per nucleus, giving an exact 2:1 ratio for the gametocytes of diploid and haploid drones, respectively. Vitellogenin was found in the hemolymph of both types of imaginal drones at 5 to 6 days, with a significantly lower titer in the diploids.

Convergent evolution of a fused sexual cycle promotes the haploid lifestyle

NASA Astrophysics Data System (ADS)

Sherwood, Racquel Kim; Scaduto, Christine M.; Torres, Sandra E.; Bennett, Richard J.

2014-02-01

Sexual reproduction is restricted to eukaryotic species and involves the fusion of haploid gametes to form a diploid cell that subsequently undergoes meiosis to generate recombinant haploid forms. This process has been extensively studied in the unicellular yeast Saccharomyces cerevisiae, which exhibits separate regulatory control over mating and meiosis. Here we address the mechanism of sexual reproduction in the related hemiascomycete species Candida lusitaniae. We demonstrate that, in contrast to S. cerevisiae, C. lusitaniae exhibits a highly integrated sexual program in which the programs regulating mating and meiosis have fused. Profiling of the C. lusitaniae sexual cycle revealed that gene expression patterns during mating and meiosis were overlapping, indicative of co-regulation. This was particularly evident for genes involved in pheromone MAPK signalling, which were highly induced throughout the sexual cycle of C. lusitaniae. Furthermore, genetic analysis showed that the orthologue of IME2, a `diploid-specific' factor in S. cerevisiae, and STE12, the master regulator of S. cerevisiae mating, were each required for progression through both mating and meiosis in C. lusitaniae. Together, our results establish that sexual reproduction has undergone significant rewiring between S. cerevisiae and C. lusitaniae, and that a concerted sexual cycle operates in C. lusitaniae that is more reminiscent of the distantly related ascomycete, Schizosaccharomyces pombe. We discuss these results in light of the evolution of sexual reproduction in yeast, and propose that regulatory coupling of mating and meiosis has evolved multiple times as an adaptation to promote the haploid lifestyle.

The Evolution of Latent Genes in Subdivided Populations

PubMed Central

Moody, M. E.; Basten, C. J.

1990-01-01

We define latent genes as phenotypically silent DNA sequences which may be reactivated by various genetic mechanisms. Of interest is how they and their functional counterparts can be maintained at high frequency in the face of mutation and selection pressure. We propose a two-deme, three-allele model incorporating viability selection, mutation and migration in haploid populations. It is shown that polymorphism for the three alleles can be easily maintained for a wide range of biologically meaningful parameter values. Computer simulations were employed to gain qualitative insight into the global dynamics of the system. It was found that the dynamics of the latent allele is closely correlated with that of the functional allele. In addition, bias in the migration rates can strengthen or weaken selective conditions for preservation of the functional and latent alleles. PMID:2307354

QGene 4.0, an extensible Java QTL-analysis platform.

PubMed

Joehanes, Roby; Nelson, James C

2008-12-01

Of many statistical methods developed to date for quantitative trait locus (QTL) analysis, only a limited subset are available in public software allowing their exploration, comparison and practical application by researchers. We have developed QGene 4.0, a plug-in platform that allows execution and comparison of a variety of modern QTL-mapping methods and supports third-party addition of new ones. The software accommodates line-cross mating designs consisting of any arbitrary sequence of selfing, backcrossing, intercrossing and haploid-doubling steps that includes map, population, and trait simulators; and is scriptable. Software and documentation are available at http://coding.plantpath.ksu.edu/qgene. Source code is available on request.

Salutary effect of pre-treatment with an Nrf2 inducer on ischemia reperfusion injury in the rat liver.

PubMed

Masuda, Yuichi; Vaziri, Nosratola D; Takasu, Chie; Li, Shiri; Robles, Lourdes; Pham, Christine; Le, Aimee; Vo, Kelly; Farzaneh, Seyed H; Stamos, Michael J; Ichii, Hirohito

2014-01-01

Ischemia-reperfusion injury (IRI) is a common phenomenon occurring during liver surgery, transplantation, and trauma. IRI causes oxidative stress which plays a critical role in causing organ damage. The Nrf2 is the master regulator of numerous genes, encoding antioxidant, detoxifying, and cytoprotective molecules. Nrf2 dysfunction has been implicated in the pathogenesis of several inflammatory disorders, cancer, and aging. This study was undertaken to investigate the effect of Nrf2 pathway activator (dh404) on warm liver IRI in a rodent model. Ten Sprague-Dawley rats were treated with dh404 or vehicle. Dh404 was dissolved in sesame oil and was given orally (1.5mg/kg) the night before and 5 hours before procedures. Rat livers were subjected to 60 minutes of 70% ischemia followed by 3 hours of reperfusion. Serum ALT and Malondialdehyde (MDA) were determined and liver tissue was processed for histological examination, and determination of apoptosis, myeloperoxidase (MPO) activity, ADP/ATP ratio, and expressions of Nrf2, eNOS, anti-oxidant enzymes, and inflammatory mediators. Serum ALT and MDA levels and tissue MPO activity were significantly lower, expression of the anti-oxidant enzyme, glutamate cysteine ligase were significantly higher, whereas expression of NFkB and COX-2 was unchanged in the dh404-treated group. Although the total Suzuki histology score did not differ significantly, the extent of sinusoidal congestion, vacuolization, and apoptosis was significantly reduced in the dh404 treated compared to the untreated group (P<0.01). Pre-treatment with dh404 resulted in partial attenuation of hepatic ischemia reperfusion injury in rats.

Segregation distortion causes large-scale differences between male and female genomes in hybrid ants.

PubMed

Kulmuni, Jonna; Seifert, Bernhard; Pamilo, Pekka

2010-04-20

Hybridization in isolated populations can lead either to hybrid breakdown and extinction or in some cases to speciation. The basis of hybrid breakdown lies in genetic incompatibilities between diverged genomes. In social Hymenoptera, the consequences of hybridization can differ from those in other animals because of haplodiploidy and sociality. Selection pressures differ between sexes because males are haploid and females are diploid. Furthermore, sociality and group living may allow survival of hybrid genotypes. We show that hybridization in Formica ants has resulted in a stable situation in which the males form two highly divergent gene pools whereas all the females are hybrids. This causes an exceptional situation with large-scale differences between male and female genomes. The genotype differences indicate strong transmission ratio distortion depending on offspring sex, whereby the mother transmits some alleles exclusively to her daughters and other alleles exclusively to her sons. The genetic differences between the sexes and the apparent lack of multilocus hybrid genotypes in males can be explained by recessive incompatibilities which cause the elimination of hybrid males because of their haploid genome. Alternatively, differentiation between sexes could be created by prezygotic segregation into male-forming and female-forming gametes in diploid females. Differentiation between sexes is stable and maintained throughout generations. The present study shows a unique outcome of hybridization and demonstrates that hybridization has the potential of generating evolutionary novelties in animals.

An informational diversity framework, illustrated with sexually deceptive orchids in early stages of speciation.

PubMed

Smouse, Peter E; Whitehead, Michael R; Peakall, Rod

2015-11-01

Reconstructing evolutionary history for emerging species complexes is notoriously difficult, with newly isolated taxa often morphologically cryptic and the signature of reproductive isolation often restricted to a few genes. Evidence from multiple loci and genomes is highly desirable, but multiple inputs require 'common currency' translation. Here we deploy a Shannon information framework, converting into diversity analogue, which provides a common currency analysis for maternally inherited haploid and bi-parentally inherited diploid nuclear markers, and then extend that analysis to construction of minimum-spanning networks for both genomes. The new approach is illustrated with a quartet of cryptic congeners from the sexually deceptive Australian orchid genus Chiloglottis, still in the early stages of speciation. Divergence is more rapid for haploid plastids than for nuclear markers, consistent with the effective population size differential (N(ep) < (N(en)), but divergence patterns are broadly correlated for the two genomes. There are nevertheless intriguing discrepancies between the emerging plastid and nuclear signals of early phylogenetic radiation of these taxa, and neither pattern is entirely consistent with the available information on the sexual cues used by the orchids to lure the pollinators enforcing reproductive isolation. We describe possible extensions of this methodology to multiple ploidy levels and other types of markers, which should increase the range of application to any taxonomic assemblage in the very early stages of reproductive isolation and speciation. © 2015 John Wiley & Sons Ltd.

The Influence of Polyploidy on the Evolution of Yeast Grown in a Sub-Optimal Carbon Source

PubMed Central

Scott, Amber L.; Richmond, Phillip A.; Dowell, Robin D.; Selmecki, Anna M.

2017-01-01

Abstract Polyploidization events have occurred during the evolution of many fungi, plant, and animal species and are thought to contribute to speciation and tumorigenesis, however little is known about how ploidy level contributes to adaptation at the molecular level. Here we integrate whole genome sequencing, RNA expression analysis, and relative fitness of ∼100 evolved clones at three ploidy levels. Independent haploid, diploid, and tetraploid populations were grown in a low carbon environment for 250 generations. We demonstrate that the key adaptive mutation in the evolved clones is predicted by a gene expression signature of just five genes. All of the adaptive mutations identified encompass a narrow set of genes, however the tetraploid clones gain a broader spectrum of adaptive mutations than haploid or diploid clones. While many of the adaptive mutations occur in genes that encode proteins with known roles in glucose sensing and transport, we discover mutations in genes with no canonical role in carbon utilization (IPT1 and MOT3), as well as identify novel dominant mutations in glucose signal transducers thought to only accumulate recessive mutations in carbon limited environments (MTH1 and RGT1). We conclude that polyploid cells explore more genotypic and phenotypic space than lower ploidy cells. Our study provides strong evidence for the beneficial role of polyploidization events that occur during the evolution of many species and during tumorigenesis. PMID:28957510

The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activator dh404 protects against diabetes-induced endothelial dysfunction.

PubMed

Sharma, Arpeeta; Rizky, Luddwi; Stefanovic, Nada; Tate, Mitchel; Ritchie, Rebecca H; Ward, Keith W; de Haan, Judy B

2017-03-03

Vascular dysfunction is a pivotal event in the development of diabetes-associated vascular disease. Increased inflammation and oxidative stress are major contributors to vascular dysfunction. Nrf2, a master regulator of several anti-oxidant genes and a suppressor of inflammatory NF-κB, has potential as a target to combat oxidative stress and inflammation. The aim of this study was to investigate the effects of a novel Nrf2 activator, the bardoxolone methyl derivative dh404, on endothelial function in vitro and in vivo. dh404 at 3 mg/kg was administered to male Akita mice, an established diabetic mouse model of insulin insufficiency and hyperglycemia, from 6 weeks of age. At 26 weeks of age, vascular reactivity was assessed by wire myography, pro-inflammatory expression was assessed in the aortas by qRT-PCR and immunohistochemistry, and systemic and vascular oxidative stress measurements were determined. Additionally, studies in human aortic endothelial cells (HAECs) derived from normal and diabetic patients in the presence or absence of dh404 included assessment of pro-inflammatory genes by qRT-PCR and western blotting. Oxidative stress was assessed by three methods; L-012, DCFDA and amplex red. Static adhesion assays were performed to determine the leukocyte-endothelial interaction in the presence or absence of dh404. Dh404 significantly attenuated endothelial dysfunction in diabetic Akita mice characterized by reduced contraction in response to phenylephrine and the downregulation of inflammatory genes (VCAM-1, ICAM-1, p65, IL-1β) and pro-oxidant genes (Nox1 and Nox2). Furthermore, reduced systemic and vascular oxidative stress levels were observed in diabetic Akita mice. dh404 exhibited cytoprotective effects in diabetic HAECs in vitro, reflected by significant upregulation of Nrf2-responsive genes, NAD(P)H quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1), reduction of oxidative stress markers (O 2 ·- and H 2 O 2 ), inhibition of inflammatory genes (VCAM-1 and the p65 subunit of NF-κB) and attenuation of leukocyte-endothelial interactions (P < 0.05 for all in vitro and in vivo parameters; one or two-way ANOVA as appropriate with post hoc testing). These studies demonstrate that upregulation of Nrf2 by dh404 represents a novel therapeutic strategy to limit diabetes-associated vascular injury.

Computational-optical microscopy for 3D biological imaging beyond the diffraction limit

NASA Astrophysics Data System (ADS)

Grover, Ginni

In recent years, super-resolution imaging has become an important fluorescent microscopy tool. It has enabled imaging of structures smaller than the optical diffraction limit with resolution less than 50 nm. Extension to high-resolution volume imaging has been achieved by integration with various optical techniques. In this thesis, development of a fluorescent microscope to enable high resolution, extended depth, three dimensional (3D) imaging is discussed; which is achieved by integration of computational methods with optical systems. In the first part of the thesis, point spread function (PSF) engineering for volume imaging is discussed. A class of PSFs, referred to as double-helix (DH) PSFs, is generated. The PSFs exhibit two focused spots in the image plane which rotate about the optical axis, encoding depth in rotation of the image. These PSFs extend the depth-of-field up to a factor of ˜5. Precision performance of the DH-PSFs, based on an information theoretical analysis, is compared with other 3D methods with conclusion that the DH-PSFs provide the best precision and the longest depth-of-field. Out of various possible DH-PSFs, a suitable PSF is obtained for super-resolution microscopy. The DH-PSFs are implemented in imaging systems, such as a microscope, with a special phase modulation at the pupil plane. Surface-relief elements which are polarization-insensitive and ˜90% light efficient are developed for phase modulation. The photon-efficient DH-PSF microscopes thus developed are used, along with optimal position estimation algorithms, for tracking and super-resolution imaging in 3D. Imaging at depths-of-field of up to 2.5 microm is achieved without focus scanning. Microtubules were imaged with 3D resolution of (6, 9, 39) nm, which is in close agreement with the theoretical limit. A quantitative study of co-localization of two proteins in volume was conducted in live bacteria. In the last part of the thesis practical aspects of the DH-PSF microscope are discussed. A method to stabilize it, for extended periods of time, with 3-4 nm precision in 3D is developed. 3D Super-resolution is demonstrated without drift. A PSF correction algorithm is demonstrated to improve characteristics of the DH-PSF in an experiment, where it is implemented with a polarization-insensitive liquid crystal spatial light modulator.

Day Hospital Mentalization-Based Treatment (MBT-DH) versus treatment as usual in the treatment of severe borderline personality disorder: protocol of a randomized controlled trial.

PubMed

Laurenssen, Elisabeth M P; Westra, Dieuwertje; Kikkert, Martijn J; Noom, Marc J; Eeren, Hester V; van Broekhuyzen, Anna J; Peen, Jaap; Luyten, Patrick; Busschbach, Jan J V; Dekker, Jack J M

2014-05-22

Severe borderline personality disorder is associated with a very high psychosocial and economic burden. Current treatment guidelines suggest that several manualized treatments, including day hospital Mentalization-Based Treatment (MBT-DH), are effective in these patients. However, only two randomized controlled trials have compared manualized MBT-DH with treatment as usual. Given the relative paucity of data supporting the efficacy and cost-effectiveness of MBT-DH, the possible influence of researcher allegiance in one of the trials, and potential problems with the generalization of findings to mental health systems in other countries, this multi-site randomized trial aims to investigate the efficacy and cost-effectiveness of manualized MBT-DH compared to manualized specialist treatment as usual in The Netherlands. The trial is being conducted at two sites in The Netherlands. Patients with a DSM-IV-TR diagnosis of borderline personality disorder and a score of ≥ 20 on the Borderline Personality Disorder Severity Index were randomly allocated to MBT-DH or treatment as usual. The MBT-DH program consists of a maximum of 18 months' intensive treatment, followed by a maximum of 18 months of maintenance therapy. Specialist treatment as usual is provided by the City Crisis Service in Amsterdam, a service that specializes in treating patients with personality disorders, offering manualized, non-MBT interventions including family interventions, Linehan training, social skills training, and pharmacotherapy, without a maximum time limit. Patients are assessed at baseline and subsequently every 6 months up to 36 months after the start of treatment. The primary outcome measure is the frequency and severity of manifestations of borderline personality disorder as assessed by the Borderline Personality Disorder Severity Index. Secondary outcome measures include parasuicidal behaviour, symptomatic distress, social and interpersonal functioning, personality functioning, attachment, capacity for mentalizing and quality of life. Cost-effectiveness is assessed in terms of the cost per quality-adjusted life year. Outcomes will be analyzed using multilevel analyses based on intention-to-treat principles. Severe borderline personality disorder is a serious psychological disorder that is associated with high burden. This multi-site randomized trial will provide further data concerning the efficacy and cost-effectiveness of MBT-DH for these patients. NTR2175.

Day Hospital Mentalization-Based Treatment (MBT-DH) versus treatment as usual in the treatment of severe borderline personality disorder: protocol of a randomized controlled trial

PubMed Central

2014-01-01

Background Severe borderline personality disorder is associated with a very high psychosocial and economic burden. Current treatment guidelines suggest that several manualized treatments, including day hospital Mentalization-Based Treatment (MBT-DH), are effective in these patients. However, only two randomized controlled trials have compared manualized MBT-DH with treatment as usual. Given the relative paucity of data supporting the efficacy and cost-effectiveness of MBT-DH, the possible influence of researcher allegiance in one of the trials, and potential problems with the generalization of findings to mental health systems in other countries, this multi-site randomized trial aims to investigate the efficacy and cost-effectiveness of manualized MBT-DH compared to manualized specialist treatment as usual in The Netherlands. Methods/design The trial is being conducted at two sites in The Netherlands. Patients with a DSM-IV-TR diagnosis of borderline personality disorder and a score of ≥ 20 on the Borderline Personality Disorder Severity Index were randomly allocated to MBT-DH or treatment as usual. The MBT-DH program consists of a maximum of 18 months’ intensive treatment, followed by a maximum of 18 months of maintenance therapy. Specialist treatment as usual is provided by the City Crisis Service in Amsterdam, a service that specializes in treating patients with personality disorders, offering manualized, non-MBT interventions including family interventions, Linehan training, social skills training, and pharmacotherapy, without a maximum time limit. Patients are assessed at baseline and subsequently every 6 months up to 36 months after the start of treatment. The primary outcome measure is the frequency and severity of manifestations of borderline personality disorder as assessed by the Borderline Personality Disorder Severity Index. Secondary outcome measures include parasuicidal behaviour, symptomatic distress, social and interpersonal functioning, personality functioning, attachment, capacity for mentalizing and quality of life. Cost-effectiveness is assessed in terms of the cost per quality-adjusted life year. Outcomes will be analyzed using multilevel analyses based on intention-to-treat principles. Discussion Severe borderline personality disorder is a serious psychological disorder that is associated with high burden. This multi-site randomized trial will provide further data concerning the efficacy and cost-effectiveness of MBT-DH for these patients. Trial registration NTR2175 PMID:24886402

Estimation of genetic parameters and detection of chromosomal regions affecting the major milk proteins and their post translational modifications in Danish Holstein and Danish Jersey cattle.

PubMed

Buitenhuis, Bart; Poulsen, Nina A; Gebreyesus, Grum; Larsen, Lotte B

2016-08-02

In the Western world bovine milk products are an important protein source in human diet. The major proteins in bovine milk are the four caseins (CN), αS1-, αS2-, β-, and k-CN and the two whey proteins, β-LG and α-LA. It has been shown that both the amount of specific CN and their isoforms including post-translational modifications (PTM) influence technological properties of milk. Therefore, the aim of this study was to 1) estimate genetic parameters for individual proteins in Danish Holstein (DH) (n = 371) and Danish Jersey (DJ) (n = 321) milk, and 2) detect genomic regions associated with specific milk protein and their different PTM forms using a genome-wide association study (GWAS) approach. For DH, high heritability estimates were found for protein percentage (0.47), casein percentage (0.43), k-CN (0.77), β-LG (0.58), and α-LA (0.40). For DJ, high heritability estimates were found for protein percentage (0.70), casein percentage (0.52), and α-LA (0.44). The heritability for G-k-CN, U-k-CN and GD was higher in the DH compared to the DJ, whereas the heritability for the PD of αS1-CN was lower in DH compared to DJ, whereas the PD for αS2-CN was higher in DH compared to DJ. The GWAS results for the main milk proteins were in line what has been earlier published. However, we showed that there were SNPs specifically regulating G-k-CN in DH. Some of these SNPs were assigned to casein protein kinase genes (CSNK1G3, PRKCQ). The genetic analysis of the major milk proteins and their PTM forms revealed that these were heritable in both DH and DJ. In DH, genomic regions specific for glycosylation of k-CN were detected. Furthermore, genomic regions for the major milk proteins confirmed the regions on BTA6 (casein cluster), BTA11 (PEAP), and BTA14 (DGAT1) as important regions influencing protein composition in milk. The results from this study provide confidence that it is possible to breed for specific milk protein including the different PTM forms.

Gravi-photomorphogenesis of the moss Pottia intermedia protonemata

NASA Astrophysics Data System (ADS)

Demkiv, O. T.; Kyjak, N. Y.; Khorkavtsiv, Y. D.; Kit, N. A.

The protonemata development proceeds in the process of gradual differentiation of growing apical cells and intercalar cells the shortened lateral branches of the latters being transformed into three-dimensional gametophore buds (Demkiv et al., 1991). Normal course of plant development needs favourable external conditions. Sometimes, however, external environment agents can accelerate the development of organism. So, apical protonema cells of darkgrown gravitropic P. intermedia differentiate gametophore-buds in light of low intensity (Ripetskyj, 1999). We investigate the influence of gravistimulation on bud formation in haploid and diploid P. intermedia protonema. Diploid protonema was found to react on light weaker than haploid one. Under the influence of light the darkgrown apical cells and lateral branches of haploid protonema were directly transformed into buds, while in diploid protonema at first the formation of bundles of rhizoid type filaments takes place on the tips of caulonema and buds appeared in center of such bundles. The participation of gravity in gametophore bud formation was assessed by clinorotating protonema in darkness. Being illuminated such protonema also developed buds quickly the latters being formed along all stolon. It can be suggested that at 1g the growth zone of apical cells actively attract inductors of bud formation. During clinorotation the inductors probably are transferred much more slower than under stationary state and that is why the buds arised not only at the tips of stolons but along all their length. It is known that gametophore bud formation can be stimulated by exogenous phytohormones. As M. Bopp (1980) has shown, that kinetin selectively promotes bud formation on moss protonema. Our observations have shown 0,5 -- 50 μ M of kinetin stimulate the bud formation on diploid aposporic protonema much more effectively that on haploid one. It can be concluded that the amount of endogenous cytokinins in haploid protonemal cells is sufficiently high and the addition of exogenous kinetin may be superfluous for bud formation being, however, not superfluous in diploid. It was established earlier that IAA participates gametophore bud formation stimulating caulonema differentiation and inducing the competence to cytokinins action. 3,0 μ M and 30,0 μ M phytotropin of N-1-naphthylphthalamic acid (NPA), the blockator of IAA efflux, were used in our investigations. 1,0 μ M of synthesized auxin I-NAA did not essentially influence gametophore bud formation in both haploid and diploid P. intermedia protonema. However, during combine action of NPA and NAA the inhibitory effect of 3,0 μ M of NPA was eliminated the ability of gravitropic protonema to form gametophore buds being renewed.

KSC-2009-2426

NASA Image and Video Library

2009-03-30

CAPE CANAVERAL, Fla. – The Science Instrument Command and Data Handling Unit, or SIC&DH, arrives at NASA's Kennedy Space Center in Florida. The SIC&DH will be installed on the Hubble Space Telescope during space shuttle Atlantis' STS-125 mission. This unit will replace the one that suffered a failure aboard the orbiting telescope on Sept. 27, 2008. The SIC&DH is being prepared for integration onto the Multi-Use Lightweight Equipment Carrier in the Payload Hazardous Servicing Facility. The carrier holds the payload for space shuttle Atlantis' STS-125 mission servicing NASA's Hubble Space Telescope, targeted to launch May 12. Photo credit: NASA/Jack Pfaller

KSC-2009-2427

NASA Image and Video Library

2009-03-30

CAPE CANAVERAL, Fla. – The Science Instrument Command and Data Handling Unit, or SIC&DH, is transferred inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida. The SIC&DH will be installed on the Hubble Space Telescope during space shuttle Atlantis' STS-125 mission. This unit will replace the one that suffered a failure aboard the orbiting telescope on Sept. 27, 2008. The SIC&DH is being prepared for integration onto the Multi-Use Lightweight Equipment Carrier .The carrier holds the payload for space shuttle Atlantis' STS-125 mission servicing NASA's Hubble Space Telescope, targeted to launch May 12. Photo credit: NASA/Jack Pfaller

[The use of the macrophage disappearance reaction for detecting delayed hypersensitivity to Yersinia pestis antigens].

PubMed

Vasil'eva, G I; Doroshenko, E P; Kiseleva, A K; Pustovalov, V L

1990-12-01

The possibility of using the reaction of macrophage disappearance (RMD) for the detection of delayed hypersensitivity (DH) to Y. pestis has been studied. As the result of these studies, RMD has been found suitable, in principle, for use in the quantitative evaluation of DH to Y. pestis. High sensitivity and specificity of this reaction have been established. The presence of DH in the process of the formation of immunity after immunization with Y. pestis antigen FIA has been shown. RMD can be observed during 28 days after immunization (the term of observation).

Comments on D/H ratios in chondritic organic matter

NASA Astrophysics Data System (ADS)

Smith, J. W.; Rigby, D.

1981-06-01

D/H ratios in chondritic organic matter are investigated. Demineralized organic residues obtained from previous experiments were dried in a quartz reaction vessel under vacuum for 60 minutes at 250-300 C and then combusted in oxygen for 20 minutes at 850 C. The apparatus is described and the results of the experiments such as D/H ratios in water and measurements on total carbon dioxide are given. Atomic H/C ratios calculated directly from the quantities of carbon dioxide and water recovered, are reported according to Standard Mean Ocean Water and Pee Dee Belemnite, using the customary notation.

Influence of Curing Mode on the Surface Energy and Sorption/Solubility of Dental Self-Adhesive Resin Cements

PubMed Central

Kim, Hyun-Jin; Bagheri, Rafat; Kim, Young Kyung; Son, Jun Sik; Kwon, Tae-Yub

2017-01-01

This study investigated the influence of curing mode (dual- or self-cure) on the surface energy and sorption/solubility of four self-adhesive resin cements (SARCs) and one conventional resin cement. The degree of conversion (DC) and surface energy parameters including degree of hydrophilicity (DH) were determined using Fourier transform infrared spectroscopy and contact angle measurements, respectively (n = 5). Sorption and solubility were assessed by mass gain or loss after storage in distilled water or lactic acid for 60 days (n = 5). A linear regression model was used to correlate between the results (%DC vs. DH and %DC/DH vs. sorption/solubility). For all materials, the dual-curing consistently produced significantly higher %DC values than the self-curing (p < 0.05). Significant negative linear regressions were established between the %DC and DH in both curing modes (p < 0.05). Overall, the SARCs showed higher sorption/solubility values, in particular when immersed in lactic acid, than the conventional resin cement. Linear regression revealed that %DC and DH were negatively and positively correlated with the sorption/solubility values, respectively. Dual-curing of SARCs seems to lower the sorption and/or solubility in comparison with self-curing by increased %DC and occasionally decreased hydrophilicity. PMID:28772489

Effect of Dorsal and Ventral Hippocampal Lesions on Contextual Fear Conditioning and Unconditioned Defensive Behavior Induced by Electrical Stimulation of the Dorsal Periaqueductal Gray

PubMed Central

Ballesteros, Carolina Irurita; de Oliveira Galvão, Bruno; Maisonette, Silvia; Landeira-Fernandez, J.

2014-01-01

The dorsal (DH) and ventral (VH) subregions of the hippocampus are involved in contextual fear conditioning. However, it is still unknown whether these two brain areas also play a role in defensive behavior induced by electrical stimulation of the dorsal periaqueductal gray (dPAG). In the present study, rats were implanted with electrodes into the dPAG to determine freezing and escape response thresholds after sham or bilateral electrolytic lesions of the DH or VH. The duration of freezing behavior that outlasted electrical stimulation of the dPAG was also measured. The next day, these animals were subjected to contextual fear conditioning using footshock as an unconditioned stimulus. Electrolytic lesions of the DH and VH impaired contextual fear conditioning. Only VH lesions disrupted conditioned freezing immediately after footshock and increased the thresholds of aversive freezing and escape responses to dPAG electrical stimulation. Neither DH nor VH lesions disrupted post-dPAG stimulation freezing. These results indicate that the VH but not DH plays an important role in aversively defensive behavior induced by dPAG electrical stimulation. Interpretations of these findings should be made with caution because of the fact that a non-fiber-sparing lesion method was employed. PMID:24404134

Applying Model-Based Reasoning to the FDIR of the Command and Data Handling Subsystem of the International Space Station

NASA Technical Reports Server (NTRS)

Robinson, Peter; Shirley, Mark; Fletcher, Daryl; Alena, Rick; Duncavage, Dan; Lee, Charles

2003-01-01

All of the International Space Station (ISS) systems which require computer control depend upon the hardware and software of the Command and Data Handling System (C&DH) system, currently a network of over 30 386-class computers called Multiplexor/Dimultiplexors (MDMs)[18]. The Caution and Warning System (C&W)[7], a set of software tasks that runs on the MDMs, is responsible for detecting, classifying, and reporting errors in all ISS subsystems including the C&DH. Fault Detection, Isolation and Recovery (FDIR) of these errors is typically handled with a combination of automatic and human effort. We are developing an Advanced Diagnostic System (ADS) to augment the C&W system with decision support tools to aid in root cause analysis as well as resolve differing human and machine C&DH state estimates. These tools which draw from sources in model-based reasoning[ 16,291, will improve the speed and accuracy of flight controllers by reducing the uncertainty in C&DH state estimation, allowing for a more complete assessment of risk. We have run tests with ISS telemetry and focus on those C&W events which relate to the C&DH system itself. This paper describes our initial results and subsequent plans.

Up-regulation of tumor suppressor genes by exogenous dhC16-Cer contributes to its anti-cancer activity in primary effusion lymphoma

PubMed Central

Lin, Zhen; Zabaleta, Jovanny; Dai, Lu; Qin, Zhiqiang

2017-01-01

Primary effusion lymphoma (PEL) is a rare and highly aggressive B-cell malignancy with Kaposi's sarcoma-associated herpesvirus (KSHV) infection, while lack of effective therapies. Our recent data indicated that targeting the sphingolipid metabolism by either sphingosine kinase inhibitor or exogenous ceramide species induces PEL cell apoptosis and suppresses tumor progression in vivo. However, the underlying mechanisms for these exogenous ceramides “killing” PEL cells remain largely unknown. Based on the microarray analysis, we found that exogenous dhC16-Cer treatment affected the expression of many cellular genes with important functions within PEL cells such as regulation of cell cycle, cell survival/proliferation, and apoptosis/anti-apoptosis. Interestingly, we found that a subset of tumor suppressor genes (TSGs) was up-regulated from dhC16-Cer treated PEL cells. One of these elevated TSGs, Thrombospondin-1 (THBS1) was required for dhC16-Cer induced PEL cell cycle arrest. Moreover, dhC16-Cer up-regulation of THBS1 was through the suppression of multiple KSHV microRNAs expression. Our data demonstrate that exogenous ceramides display anti-cancer activities for PEL through regulation of both host and oncogenic virus factors. PMID:28146424

Deuterium-rich Water in Meteorites

NASA Astrophysics Data System (ADS)

Deloule, E.; Robert, F.

1995-09-01

D/H ratios of 2 meteorites (Renazzo CR and Semarkona LL3), which are known to exhibit the largest departures from the terrestrial hydrogen isotopic ratios, have been determined with the CRPG Nancy ion-microprobe. Correlations between the D/H ratios and the chemical compositions (H2O, K, Si, C/H) of plausible hydrogen carriers were observed. From these correlations, it is possible to show that, contrary to previous interpretations, phyllosilicates are the carriers of the deuterium-rich hydrogen in Semarkona and Renazzo : 870 x10-6 D/H 670 x106 (+4600 dD 3300) and 320 x10-6 (dD 1050), respectively. Hydrogen is also present in the chondrules of these two deuterium-rich meteorites. Isotopic equilibrium between the deuterium depleted phases and the deuterium-rich phyllosilicates was never attained. This is illustrated at a micron scale by the D/H ratios obtained continuously during a 3 hours measurement on a same position (see figure below). It can be seen that water-rich mineral(s) having D/H up to 550 x10-6 (dD = +2500) are in contact with a mineral having D/H = 234 x10-6 (dD = +500). The thickness of the boundary where the diffusion of hydrogen took place is restricted to less than 0.2 mm. Such isotopic heterogeneity is quite spectacular if one remembers that the isotopic variations that we can see within these 0.2 mm are an order of magnitude larger than the total observed variations on Earth. The large differences in D/H ratios between matrix (up to 700 x 10-6, dD up to +3500) and chondrules (from 120 x10-6 (dD = -230) to 230 x10-6 (dD = +475)) show that hydrogen in chondrules cannot originate from the matrix by simple contamination or diffusion processes. The high D/H ratios measured in water bearing minerals could not have been produced thermally within a dense solar nebula. Chemical reactions (i.e. involving ions or radicals), taking place in interstellar space or in the outer regions of the nebula at 110-140K are presently the only conceivable mechanisms capable of yielding such isotopic enrichments. Hydrogen isotopic composition and water concentration versus depth in the matrix of Semarkona. The profile was obtained by sputtering the minerals with the primary beam of the ion-probe (0 stands for the surface mineral). Note the complete lack of isotopic homogenisation between the hydrogen bearing phases : the D/H ratio increases within 0.2 mm by more than 300x10-6; that is one order of magnitude larger than the total variations on Earth. Such a distribution demonstrates that no secondary processes altered the pristine isotopic ratios established at the time of mineral formation.

D/H in Water Evolved from Martian Rocks in Gale Crater

NASA Astrophysics Data System (ADS)

Mahaffy, P. R.; Franz, H. B.; Atreya, S. K.; Webster, C. R.

2017-12-01

The Sample Analysis at Mars (SAM) instrument suite with its Quadrupole Mass Spectrometer (QMS) and Tunable Laser Spectrometer (TSL) measures isotopes such as δ34S in SO2 [1], δ37Cl in HCl [2], δ15N in N2 or NO [3], δ13C in CH4 [4], δ13C and δ18O in CO2 [5-6], δD in H2O [7], and a variety of noble gas isotopes [8-9]. Fractionation of isotopes of H, C, O, N, Ar, and Xe indicates a substantial loss of atmosphere to space. For xenon this may have occurred early in the history of Mars by hydrodynamic escape [10] or spread over time for C, O, N, and Ar [11]. Nevertheless, the detailed history of atmospheric loss and the predictions of the climate when the Gale crater was a lake are still not well constrained. Isotopes from light elements that are presently measured in the atmosphere but that were also locked into minerals in rocks more than 3 billion years ago are of particular interest as they may provide additional constraints on the history of atmospheric loss. These include 15N/14N presently measured in atmospheric N2 [3] but also in nitrogen released from ancient nitrates as NO [12] and D/H in atmospheric water [13] and in water or hydroxyl locked into minerals and released in the SAM evolved gas analysis (EGA) experiments [7]. D/H in water can be measured by both the TSL and the QMS. Typically the D/H decreases over the course of the EGA temperature ramp, since gas that has exchanged with the current atmosphere is released at lower temperatures. Less easily exchanged gas reflecting the D/H ratio in the water of formation of a mineral, such as that from the dehydroxylation of a phylosillicate, is released at higher temperatures. We will examine some of the D/H measurements made on drilled and powdered rocks and the trends in the variation of the D/H ratio with release temperature. We will compare these ratios with the D/H in atmospheric water and discuss possible consequences for loss of D/H over time. References: [1] Franz et al., in press. [2] Farley et al. (2016) EPSL 438. [3] Wong et al. (2013) GRL 40. [4] Webster et al. (2011) PSS 59. [5] Mahaffy et al. (2013) Science 341. [6] Webster et al. (2013) Science 341. [7] Mahaffy et al. (2015) Science 347. [8] Atreya et al. (2013) GRL 40. [9] Conrad et al. (2016) EPSL 454. [10] Pepin et al. (2006) EPSL 252. [11] Jakosky et al. (1994) Icarus 111. [12] Stern, this meeting. [13] Villaneuva et al. (2015) Science 348.

Transfer of Herb-Resistance Plasmid From Escherichia coli to Staphylococcus aureus Residing in the Human Urinary Tract

PubMed Central

Tong, Yan Qing; Xin, Bing; Zhu, Li

2014-01-01

Background: Plasmid transfer among bacteria provides a means for dissemination of resistance. Plasmid Analysis has made it possible to track plasmids that induce resistance in bacterial population. Objectives: To screen the presence of herb-resistance plasmid in Escherichia coli strains and determine the transferability of this resistance plasmid directly from E. coli to the Gram-positive, Staphylococcus aureus. Materials and Methods: The donor strain E. coli CP9 and recipient strain S. aureus RN450RF were isolated from UTI patients. E. coli CP9 was highly resistant to herbal concoction. Isolates of S. aureus RN450RF were fully susceptible. Total plasmid DNA was prepared and transferred into E. coli DH5α. Transconjugants were selected on agar plates containing serial dilutions of herbal concoction. Resistance plasmid was transferred to susceptible S. aureus RN450RFin triple replicas. The mating experiments were repeated twice. Results: The identified 45 kb herb-resistance plasmid could be transferred from E. coli CP9 isolates to E. coli DH5α. As a consequence E. coli DH5α transconjugant MIC increased from 0.0125 g/mL to 0.25 g/mL. The plasmid was easily transferred from E. coli CP9 strain to S. aureus RN450RF with a mean transfer rate of 1×10-2 transconjugants/recipient. The E. coli donor and the S. aureus RN450RF transconjugant contained a plasmid of the same size, which was absent in the recipient before mating. Susceptibility testing showed that the S. aureus RN450RF transconjugant was resistant to herbal concoction. Conclusions: E. coli herb-resistance plasmid can replicate and be expressed in S. aureus. PMID:25147679

A review of seafood safety after the deepwater horizon blowout.

PubMed

Gohlke, Julia M; Doke, Dzigbodi; Tipre, Meghan; Leader, Mark; Fitzgerald, Timothy

2011-08-01

The Deepwater Horizon (DH) blowout resulted in fisheries closings across the Gulf of Mexico. Federal agencies, in collaboration with impacted Gulf states, developed a protocol to determine when it is safe to reopen fisheries based on sensory and chemical analyses of seafood. All federal waters have been reopened, yet concerns have been raised regarding the robustness of the protocol to identify all potential harmful exposures and protect the most sensitive populations. We aimed to assess this protocol based on comparisons with previous oil spills, published testing results, and current knowledge regarding chemicals released during the DH oil spill. We performed a comprehensive review of relevant scientific journal articles and government documents concerning seafood contamination and oil spills and consulted with academic and government experts. Protocols to evaluate seafood safety before reopening fisheries have relied on risk assessment of health impacts from polycyclic aromatic hydrocarbon (PAH) exposures, but metal contamination may also be a concern. Assumptions used to determine levels of concern (LOCs) after oil spills have not been consistent across risk assessments performed after oil spills. Chemical testing results after the DH oil spill suggest PAH levels are at or below levels reported after previous oil spills, and well below LOCs, even when more conservative parameters are used to estimate risk. We recommend use of a range of plausible risk parameters to set bounds around LOCs, comparisons of post-spill measurements with baseline levels, and the development and implementation of long-term monitoring strategies for metals as well as PAHs and dispersant components. In addition, the methods, results, and uncertainties associated with estimating seafood safety after oil spills should be communicated in a transparent and timely manner, and stakeholders should be actively involved in developing a long-term monitoring strategy.

Direct pyrogenic input from prostaglandin EP3 receptor-expressing preoptic neurons to the dorsomedial hypothalamus

PubMed Central

Nakamura, Yoshiko; Nakamura, Kazuhiro; Matsumura, Kiyoshi; Kobayashi, Shigeo; Kaneko, Takeshi; Morrison, Shaun F.

2008-01-01

Fever is induced by the neuronal mechanism in the brain. Prostaglandin (PG) E2 acts as a pyrogenic mediator in the preoptic area (POA) probably through the EP3 subtype of PGE receptor expressed on GABAergic neurons, and this PGE2 action triggers neuronal pathways for sympathetic thermogenesis in peripheral effector organs including brown adipose tissue (BAT). To explore pyrogenic efferent pathways from the POA, we here determined projection targets of EP3 receptor-expressing POA neurons with a special focus on rat hypothalamic regions including the dorsomedial hypothalamic nucleus (DMH), which is known as a center for autonomic responses to stress. Among injections of cholera toxin b-subunit (CTb), a retrograde tracer, into hypothalamic regions at the rostrocaudal level of the DMH, injections into the DMH, lateral hypothalamic area (LH), and dorsal hypothalamic area (DH) resulted in EP3 receptor immunolabeling in substantial populations of CTb-labeled neurons in the POA. Bilateral microinjections of muscimol, a GABAA receptor agonist, into the DMH and a ventral region of the DH, but not those into the LH, inhibited thermogenic (BAT sympathetic nerve activity, BAT temperature, core body temperature, and expired CO2) and cardiovascular (arterial pressure and heart rate) responses to an intra-POA PGE2 microinjection. Further immunohistochemical observations revealed close association of POA-derived GABAergic axon swellings with DMH neurons projecting to the medullary raphe regions where sympathetic premotor neurons for febrile and thermoregulatory responses are localized. These results suggest that a direct projection of EP3 receptor-expressing POA neurons to the DMH/DH region mediates febrile responses via a GABAergic mechanism. PMID:16367780

Using genomic data to develop chloroplast DNA SSRs for the Neotropical liana Stizophyllum riparium (Bignonieae, Bignoniaceae)1

PubMed Central

Beyer, Maila; Nazareno, Alison G.; Lohmann, Lúcia G.

2017-01-01

Premise of the study: We developed chloroplast microsatellite markers (cpSSRs) to be used to study the patterns of genetic structure and genetic diversity of populations of Stizophyllum riparium (Bignonieae, Bignoniaceae). Methods and Results: We used genomic data obtained through an Illumina HiSeq sequencing platform to develop a set of cpSSRs for S. riparium. A total of 36 primer pairs were developed, of which 28 displayed polymorphisms across 59 individuals from three populations. Two to 12 alleles were recorded, and the unbiased haploid diversity per locus ranged from 0.037 to 0.905. All 28 cpSSRs presented transferability to two closely related species, S. inaequilaterum and S. perforatum. Conclusions: We report a set of 28 cpSSRs for S. riparium. All markers were shown to be variable in S. riparium, indicating that these markers will be valuable for population genetic studies across S. riparium and congeneric species. PMID:29109920

Quantifying male attractiveness.

PubMed Central

McNamara, John M; Houston, Alasdair I; Marques Dos Santos, Miguel; Kokko, Hanna; Brooks, Rob

2003-01-01

Genetic models of sexual selection are concerned with a dynamic process in which female preference and male trait values coevolve. We present a rigorous method for characterizing evolutionary endpoints of this process in phenotypic terms. In our phenotypic characterization the mate-choice strategy of female population members determines how attractive females should find each male, and a population is evolutionarily stable if population members are actually behaving in this way. This provides a justification of phenotypic explanations of sexual selection and the insights into sexual selection that they provide. Furthermore, the phenotypic approach also has enormous advantages over a genetic approach when computing evolutionarily stable mate-choice strategies, especially when strategies are allowed to be complex time-dependent preference rules. For simplicity and clarity our analysis deals with haploid mate-choice genetics and a male trait that is inherited phenotypically, for example by vertical cultural transmission. The method is, however, easily extendible to other cases. An example illustrates that the sexy son phenomenon can occur when there is phenotypic inheritance of the male trait. PMID:14561306

Epistasis can accelerate adaptive diversification in haploid asexual populations.

PubMed

Griswold, Cortland K

2015-03-07

A fundamental goal of the biological sciences is to determine processes that facilitate the evolution of diversity. These processes can be separated into ecological, physiological, developmental and genetic. An ecological process that facilitates diversification is frequency-dependent selection caused by competition. Models of frequency-dependent adaptive diversification have generally assumed a genetic basis of phenotype that is non-epistatic. Here, we present a model that indicates diversification is accelerated by an epistatic basis of phenotype in combination with a competition model that invokes frequency-dependent selection. Our model makes use of a genealogical model of epistasis and insights into the effects of balancing selection on the genealogical structure of a population to understand how epistasis can facilitate diversification. The finding that epistasis facilitates diversification may be informative with respect to empirical results that indicate an epistatic basis of phenotype in experimental bacterial populations that experienced adaptive diversification. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Genetic architecture of fusarium head blight resistance in four winter triticale populations.

PubMed

Kalih, R; Maurer, H P; Miedaner, T

2015-03-01

Fusarium head blight (FHB) is a devastating disease that causes significant reductions in yield and quality in wheat, rye, and triticale. In triticale, knowledge of the genetic architecture of FHB resistance is missing but essential due to modern breeding requirements. In our study, four doubled-haploid triticale populations (N=120 to 200) were evaluated for resistance to FHB caused by artificial inoculation with Fusarium culmorum in four environments. DArT markers were used to genotype triticale populations. Seventeen quantitative trait loci (QTL) for FHB resistance were detected across all populations; six of them were derived from rye genome and located on chromosomes 4R, 5R, and 7R, which are here reported for the first time. The total cross-validated ratio of the explained phenotypic variance for all detected QTL in each population was 41 to 68%. In all, 17 QTL for plant height and 18 QTL for heading stage were also detected across all populations; 3 and 5 of them, respectively, were overlapping with QTL for FHB. In conclusion, FHB resistance in triticale is caused by a multitude of QTL, and pyramiding them contributes to higher resistance.

Interaction between the basolateral amygdala and dorsal hippocampus is critical for cocaine memory reconsolidation and subsequent drug context-induced cocaine-seeking behavior in rats

PubMed Central

Wells, Audrey M.; Lasseter, Heather C.; Xie, Xiaohu; Cowhey, Kate E.; Reittinger, Andrew M.; Fuchs, Rita A.

2011-01-01

Contextual stimulus control over instrumental drug-seeking behavior relies on the reconsolidation of context-response-drug associative memories into long-term memory storage following retrieval-induced destabilization. According to previous studies, the basolateral amygdala (BLA) and dorsal hippocampus (DH) regulate cocaine-related memory reconsolidation; however, it is not known whether these brain regions interact or independently control this phenomenon. To investigate this question, rats were trained to lever press for cocaine reinforcement in a distinct environmental context followed by extinction training in a different context. Rats were then briefly re-exposed to the cocaine-paired context to destabilize cocaine-related memories, or they were exposed to an unpaired context. Immediately thereafter, the rats received unilateral microinfusions of anisomycin (ANI) into the BLA plus baclofen/muscimol (B/M) into the contralateral (BLA/DH disconnection) or ipsilateral DH, or they received contralateral or ipsilateral microinfusions of vehicle. They then remained in their home cages overnight or for 21 d, followed by additional extinction training and a test of cocaine-seeking behavior (nonreinforced active lever responding). BLA/DH disconnection following re-exposure to the cocaine-paired context, but not the unpaired context, impaired subsequent drug context-induced cocaine-seeking behavior relative to vehicle or ipsilateral ANI + B/M treatment. Prolonged home cage stay elicited a time-dependent increase, or incubation, of drug-context-induced cocaine-seeking behavior, and BLA/DH disconnection inhibited this incubation effect despite some recovery of cocaine-seeking behavior. Thus, the BLA and DH interact to regulate the reconsolidation of cocaine-related associative memories, thereby facilitating the ability of drug-paired contexts to trigger cocaine-seeking behavior and contributing to the incubation of cocaine-seeking behavior. PMID:22005750

Efficient reductive amination process for enantioselective synthesis of L-phosphinothricin applying engineered glutamate dehydrogenase.

PubMed

Yin, Xinjian; Wu, Jianping; Yang, Lirong

2018-05-01

The objective of this study was to identify and exploit a robust biocatalyst that can be applied in reductive amination for enantioselective synthesis of the competitive herbicide L-phosphinothricin. Applying a genome mining-based library construction strategy, eight NADPH-specific glutamate dehydrogenases (GluDHs) were identified for reductively aminating 2-oxo-4-[(hydroxy)(methyl)phosphinoyl]butyric acid (PPO) to L-phosphinothricin. Among them, the glutamate dehydrogenase cloned from Pseudomonas putida (PpGluDH) exhibited relatively high catalytic activity and favorable soluble expression. This enzyme was purified to homogeneity for further characterization. The specific activity of PpGluDH was 296.1 U/g-protein, which is significantly higher than the reported value for a GluDH. To the best of our knowledge, there has not been any report on protein engineering of GluDH for PPO-oriented activity. Taking full advantage of the available information and the diverse characteristics of the enzymes in the enzyme library, PpGluDH was engineered by site-directed mutation based on multiple sequence alignment. The mutant I170M, which had 2.1-fold enhanced activity, was successfully produced. When the I170M mutant was applied in the batch production of L-phosphinothricin, it showed markedly improved catalytic efficiency compared with the wild type enzyme. The conversion reached 99% (0.1 M PPO) with an L-phosphinothricin productivity of 1.35 g/h·L, which far surpassed the previously reported level. These results show that PpGluDH I170M is a promising biocatalyst for highly enantioselective synthesis of L-phosphinothricin by reductive amination.

Ion strength limit of computed excess functions based on the linearized Poisson-Boltzmann equation.

PubMed

Fraenkel, Dan

2015-12-05

The linearized Poisson-Boltzmann (L-PB) equation is examined for its κ-range of validity (κ, Debye reciprocal length). This is done for the Debye-Hückel (DH) theory, i.e., using a single ion size, and for the SiS treatment (D. Fraenkel, Mol. Phys. 2010, 108, 1435), which extends the DH theory to the case of ion-size dissimilarity (therefore dubbed DH-SiS). The linearization of the PB equation has been claimed responsible for the DH theory's failure to fit with experiment at > 0.1 m; but DH-SiS fits with data of the mean ionic activity coefficient, γ± (molal), against m, even at m > 1 (κ > 0.33 Å(-1) ). The SiS expressions combine the overall extra-electrostatic potential energy of the smaller ion, as central ion-Ψa>b (κ), with that of the larger ion, as central ion-Ψb>a (κ); a and b are, respectively, the counterion and co-ion distances of closest approach. Ψa>b and Ψb>a are derived from the L-PB equation, which appears to conflict with their being effective up to moderate electrolyte concentrations (≈1 m). However, the L-PB equation can be valid up to κ ≥ 1.3 Å(-1) if one abandons the 1/κ criterion for its effectiveness and, instead, use, as criterion, the mean-field electrostatic interaction potential of the central ion with its ion cloud, at a radial distance dividing the cloud charge into two equal parts. The DH theory's failure is, thus, not because of using the L-PB equation; the lethal approximation is assigning a single size to the positive and negative ions. © 2015 Wiley Periodicals, Inc.

The impact of maternal plasma volume expansion and antihypertensive treatment with intravenous dihydralazine on fetal and maternal hemodynamics during pre-eclampsia: a clinical, echo-Doppler and viscometric study.

PubMed

Boito, S M E; Struijk, P C; Pop, G A M; Visser, W; Steegers, E A P; Wladimiroff, J W

2004-04-01

To establish the effects of plasma volume expansion (PVE) followed by intravenous dihydralazine (DH) administration on maternal whole blood viscosity (WBV) and hematocrit, uteroplacental and fetoplacental downstream impedance and umbilical venous (UV) volume flow in pre-eclampsia. In 13 pre-eclamptic women maternal and fetal hemodynamics were established by means of combined measurement of maternal arterial blood pressure (BP), WBV, hematocrit and uterine artery (UtA) resistance index (RI) in addition to umbilical artery (UA) pulsatility index (PI) and UV volume flow obtained from UV vessel area and UV time-averaged flow velocity. In each woman all parameters were measured four times at baseline, after PVE, after DH and 24 h after the start of treatment. Maternal diastolic BP, hematocrit and WBV display a significant reduction after PVE. In the fetus UA PI decreases significantly whereas a significant increase in UV cross-sectional area was detected. After maternal DH administration, arterial systolic and diastolic BP and UA PI show a significant decrease compared with the measurements following PVE. At 24 h, only maternal systolic and diastolic BP display a significant further decrease. No significant changes were established for the UtA RI, UV time-averaged velocity and UV volume flow during the entire study period. During pre-eclampsia, maternal PVE followed by DH administration results in a significant reduction in maternal diastolic BP, maternal hematocrit and WBV. Maternal PVE is associated with a significant increase in UV cross-sectional area and a non-significant rise of 11% in UV volume flow. Maternal DH administration does not result in any change in UV cross-sectional area. However, UA PI decreases significantly after both PVE and DH treatment. Copyright 2004 ISUOG.

Effects of concomitant diabetes mellitus and hyperthyroidism on testicular and epididymal histoarchitecture and steroidogenesis in male animals*

PubMed Central

Korejo, Nazar Ali; Wei, Quan-wei; Shah, Atta Hussain; Shi, Fang-xiong

2016-01-01

This study evaluated the effects of comorbid disorders of diabetes and hyperthyroidism in the adult male mice. In total, 32 ICR strain mice were equally distributed into four groups: control (C), diabetic (D), diabetic-plus-hyperthyroid (DH), and hyperthyroid (H). Mice allocated for diabetes received a single intraperitoneal injection of streptozotocin (STZ) at 200 mg/kg body weight. At the onset of diabetes, one group of mice was concomitantly injected levothyroxine (LT4; 0.3 mg/kg body weight) and the other set of animals received the same treatment independently on a daily basis. The body weight, as well as the testicular and epididymal weights, was reduced markedly in D and DH mice. Higher trends of blood glucose levels were seen in the DH group, in comparison to euthyroid diabetic mice. Thyroid hormones could exert a transient effect on blood glucose homeostasis by altering the serum blood glucose level in diabetic patients. Histomorphometric analysis showed increased luminal sizes of seminiferous tubules, along with decreased epithelial height and atrophic changes in germinal stem cells in the testis of DH and H mice. Caput epididymis of DH mice showed extensive compaction of principal cells, loss of stereocilia, lipid vacuolization, and inflammatory infiltrations; however, damaged tubular integrity, packed clear cells, exfoliated cells, and round spermatids were profoundly noticed in the cauda epididymis. Hyperthyroidism elevated the serum testosterone levels in H and DH mice and produced critical damages to the histoarchitecture of the epididymis. Collectively, this experiment endeavored to mimic the polyglandular autoimmune syndrome, which will be helpful to better understand the reasons for male infertility in diabetic-cum-hyperthyroid patients. PMID:27819132

Effects of concomitant diabetes mellitus and hyperthyroidism on testicular and epididymal histoarchitecture and steroidogenesis in male animals.

PubMed

Korejo, Nazar Ali; Wei, Quan-Wei; Shah, Atta Hussain; Shi, Fang-Xiong

This study evaluated the effects of comorbid disorders of diabetes and hyperthyroidism in the adult male mice. In total, 32 ICR strain mice were equally distributed into four groups: control (C), diabetic (D), diabetic-plus-hyperthyroid (DH), and hyperthyroid (H). Mice allocated for diabetes received a single intraperitoneal injection of streptozotocin (STZ) at 200 mg/kg body weight. At the onset of diabetes, one group of mice was concomitantly injected levothyroxine (LT4; 0.3 mg/kg body weight) and the other set of animals received the same treatment independently on a daily basis. The body weight, as well as the testicular and epididymal weights, was reduced markedly in D and DH mice. Higher trends of blood glucose levels were seen in the DH group, in comparison to euthyroid diabetic mice. Thyroid hormones could exert a transient effect on blood glucose homeostasis by altering the serum blood glucose level in diabetic patients. Histomorphometric analysis showed increased luminal sizes of seminiferous tubules, along with decreased epithelial height and atrophic changes in germinal stem cells in the testis of DH and H mice. Caput epididymis of DH mice showed extensive compaction of principal cells, loss of stereocilia, lipid vacuolization, and inflammatory infiltrations; however, damaged tubular integrity, packed clear cells, exfoliated cells, and round spermatids were profoundly noticed in the cauda epididymis. Hyperthyroidism elevated the serum testosterone levels in H and DH mice and produced critical damages to the histoarchitecture of the epididymis. Collectively, this experiment endeavored to mimic the polyglandular autoimmune syndrome, which will be helpful to better understand the reasons for male infertility in diabetic-cum-hyperthyroid patients.

Compatible Models of Carbon Content of Individual Trees on a Cunninghamia lanceolata Plantation in Fujian Province, China

PubMed Central

Zhuo, Lin; Tao, Hong; Wei, Hong; Chengzhen, Wu

2016-01-01

We tried to establish compatible carbon content models of individual trees for a Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantation from Fujian province in southeast China. In general, compatibility requires that the sum of components equal the whole tree, meaning that the sum of percentages calculated from component equations should equal 100%. Thus, we used multiple approaches to simulate carbon content in boles, branches, foliage leaves, roots and the whole individual trees. The approaches included (i) single optimal fitting (SOF), (ii) nonlinear adjustment in proportion (NAP) and (iii) nonlinear seemingly unrelated regression (NSUR). These approaches were used in combination with variables relating diameter at breast height (D) and tree height (H), such as D, D2H, DH and D&H (where D&H means two separate variables in bivariate model). Power, exponential and polynomial functions were tested as well as a new general function model was proposed by this study. Weighted least squares regression models were employed to eliminate heteroscedasticity. Model performances were evaluated by using mean residuals, residual variance, mean square error and the determination coefficient. The results indicated that models with two dimensional variables (DH, D2H and D&H) were always superior to those with a single variable (D). The D&H variable combination was found to be the most useful predictor. Of all the approaches, SOF could establish a single optimal model separately, but there were deviations in estimating results due to existing incompatibilities, while NAP and NSUR could ensure predictions compatibility. Simultaneously, we found that the new general model had better accuracy than others. In conclusion, we recommend that the new general model be used to estimate carbon content for Chinese fir and considered for other vegetation types as well. PMID:26982054

Participation of PLA2 and PLC in DhL-induced activation of Rhinella arenarum oocytes.

PubMed

Zapata-Martínez, J; Medina, M F; Gramajo-Bühler, M C; Sánchez-Toranzo, G

2016-08-01

Rhinella arenarum oocytes can be artificially activated, a process known as parthenogenesis, by a sesquiterpenic lactone of the guaianolide group, dehydroleucodine (DhL). Transient increases in the concentration of cytosolic Ca2+ are essential to trigger egg activation events. In this sense, the 1-4-5 inositol triphosphate receptors (IP3R) seem to be involved in the Ca2+ transient release induced by DhL in this species. We analyzed the involvement of phosphoinositide metabolism, especially the participation of phospholipase A2 (PLA2) and phospholipase C (PLC) in DhL-induced activation. Different doses of quinacrine, aristolochic acid (ATA) (PLA2 inhibitors) or neomycin, an antibiotic that binds to PIP2, thus preventing its hydrolysis, were used in mature Rhinella arenarum oocytes. In order to assay the participation of PI-PLC and PC- PLC we used U73122, a competitive inhibitor of PI-PLC dependent events and D609, an inhibitor of PC-PLC. We found that PLA2 inhibits quinacrine more effectively than ATA. This difference could be explained by the fact that quinacrine is not a specific inhibitor for PLA2 while ATA is specific for this enzyme. With respect to the participation of PLC, a higher decrease in oocyte activation was detected when cells were exposed to neomycin. Inhibition of PC-PLC with D609 and IP-PLC with U73122 indicated that the last PLC has a significant participation in the effect of DhL-induced activation. Results would indicate that DhL induces activation of in vitro matured oocytes of Rhinella arenarum by activation of IP-PLC, which in turn may induce IP3 formation which produces Ca2+ release.

Recognizing the Effects of Terrestrial Contamination on D/H Ratios in Shergottite Phosphates

NASA Technical Reports Server (NTRS)

Ross, D. K.; Ito, M.; Hervig, R.; Rao, M. N.; Nyquist, L. E.

2011-01-01

Hydrogen isotope ratios in shergottite phosphate minerals have been investigated by SIMS in the meteorites Queen Alexandra Range (QUE) 94201 and Los Angeles. We have also collected electron probe data on these phosphates in order to characterize the phosphate minerals and attempt to document any potential hydrogen isotopic differences between chlor-apatite and whitlockite. In the section of Los Angeles we studied (748), we found both chlor-apatite and whitlockite, but in the section of QUE 94201,38 studied, we found only whitlockite. In both meteorites, D/H ratios (expressed in units of delta D (sub SMOW) vary, from terrestrial values up to approximately 5400%o in QUE 94201, and to approximately 3800%o in Los Angeles. We have carefully examined the ion probed pits with high-resolution FE-SEM. In most cases where the D/H ratios are low, we have iden-tified cracks that instersect the ion probe pit. These cracks are not visible in the optical microscope attached to the SIMS instument, making them impossible to avoid during SIMS data collection. We contend that the low ratios are a function of substantial terrestrial contamination, and that similar contamination is a likely factor in previously published studies on D/H ratios in martian phosphates. Here we highlight the difficulty of attempts to constrain the martian mantle D/H ratio using phosphate data, given that both terrestrial contamination and martian mantle hydrogen will move phosphate D/H ratios in the same direction, toward lower values. We note that our data include some of the most deuterium-rich values ever reported for martian phosphates. It is clear that some of our measurements are only minimally or totally uncontaminated, but the question arises, are intermediate values diminished because of true martian variability, or do they reflect contamination?

Contribution of Hippocampal 5-HT3 Receptors in Hippocampal Autophagy and Extinction of Conditioned Fear Responses after a Single Prolonged Stress Exposure in Rats.

PubMed

Wu, Zhong-Min; Yang, Li-Hua; Cui, Rong; Ni, Gui-Lian; Wu, Feng-Tian; Liang, Yong

2017-05-01

One of the hypotheses about the pathogenesis of posttraumatic stress disorder (PTSD) is the dysfunction of serotonin (5-HT) neurotransmission. While certain 5-HT receptor subtypes are likely critical for the symptoms of PTSD, few studies have examined the role of 5-HT 3 receptor in the development of PTSD, even though 5-HT 3 receptor is critical for contextual fear extinction and anxiety-like behavior. Therefore, we hypothesized that stimulation of 5-HT 3 receptor in the dorsal hippocampus (DH) could prevent hippocampal autophagy and the development of PTSD-like behavior in animals. To this end, we infused SR57227, selective 5-HT 3 agonist, into the DH after a single prolonged stress (SPS) treatment in rats. Three weeks later, we evaluated the effects of this pharmacological treatment on anxiety-related behaviors and extinction of contextual fear memory. We also accessed hippocampal autophagy and the expression of 5-HT 3A subunit, Beclin-1, LC3-I, and LC3-II in the DH. We found that SPS treatment did not alter anxiety-related behaviors but prolonged the extinction of contextual fear memory, and such a behavioral phenomenon was correlated with increased hippocampal autophagy, decreased 5-HT 3A expression, and increased expression of Beclin-1 and LC3-II/LC3-I ratio in the DH. Furthermore, intraDH infusions of SR57227 dose-dependently promoted the extinction of contextual fear memory, prevented hippocampal autophagy, and decreased expression of Beclin-1 and LC3-II/LC3-I ratio in the DH. These results indicated that 5-HT 3 receptor in the hippocampus may play a critical role in the pathogenesis of hippocampal autophagy, and is likely involved in the pathophysiology of PTSD.

Role of Complement C5 in Experimental Blunt Chest Trauma-Induced Septic Acute Lung Injury (ALI)

PubMed Central

Karbach, Michael; Braumueller, Sonja; Kellermann, Philipp; Gebhard, Florian; Huber-Lang, Markus; Perl, Mario

2016-01-01

Background Severe blunt chest trauma is associated with high mortality. Sepsis represents a serious risk factor for mortality in acute respiratory distress syndrome (ARDS). In septic patients with ARDS complement activation products were found to be elevated in the plasma. In single models like LPS or trauma complement has been studied to some degree, however in clinically highly relevant double hit models such as the one used here little data is available. Here, we hypothesized that absence of C5 is correlated with a decreased inflammatory response in trauma induced septic acute lung injury. Methods 12 hrs after DH in mice the local and systemic cytokines and chemokines were quantified by multiplex bead array or ELISA, activated caspase-3 by western blot. Data were analyzed using one-way ANOVA followed by post-hoc Sidak’s multiple comparison test (significance, p≤ 0.05). Results In lung tissue interleukin (IL)-6, monocyte chemo attractant protein-1 (MCP-1) and granulocyte-colony stimulating factor (G-CSF) was elevated in both C5-/- mice and wildtype littermates (wt), whereas caspase-3 was reduced in lungs after DH in C5-/- mice. Systemically, reduced keratinocyte-derived chemokine (KC) levels were observed after DH in C5-/- compared to wt mice. Locally, lung myeloperoxidase (MPO), protein, IL-6, MCP-1 and G-CSF in brochoalveolar lavage fluid (BALF) were elevated after DH in C5-/- compared to wt. Conclusions In the complex but clinically relevant DH model the local and systemic inflammatory immune response features both, C5-dependent and C5-independent characteristics. Activation of caspase-3 in lung tissue after DH was C5-dependent whereas local inflammation in lung tissue was C5-independent. PMID:27437704

insilico Characterization and Homology Modeling of Arabitol Dehydrogenase (ArDH) from Candida albican.

PubMed

Sarwar, Muhammad Waseem; Saleem, Irum Baddisha; Ali, Asif; Abbas, Farhat

2013-01-01

Arabitol dehydrogenase (ArDH) is involved in the production of different sugar alcohols like arabitol, sorbitol, mannitol, erythritol and xylitol by using five carbon sugars as substrate. Arabinose, d-ribose, d-ribulose, xylose and d-xylulose are known substrate of this enzyme. ArDH is mainly produced by osmophilic fungi for the conversion of ribulose to arabitol under stress conditions. Recently this enzyme has been used by various industries for the production of pharmaceutically important sugar alcohols form cheap source than glucose. But the information at structure level as well as its binding energy analysis with different substrates was missing. The present study was focused on sequence analysis, insilico characterization and substrate binding analysis of ArDH from a fungus specie candida albican. Sequence analysis and physicochemical properties showed that this protein is highly stable, negatively charged and having more hydrophilic regions, these properties made this enzyme to bind with number of five carbon sugars as substrate. The predicted 3D model will helpful for further structure based studies. Docking analysis provided free energies of binding of each substrate from a best pose as arabinose -9.8224calK/mol, dribose -11.3701Kcal/mol, d-ribulose -8.9230Kcal/mol, xylose -9.7007Kcal/mol and d-xylulose 9.7802Kcal/mol. Our study provided insight information of structure and interactions of ArDH with its substrate. These results obtained from this study clearly indicate that d-ribose is best substrate for ArDH for the production of sugar alcohols. This information will be helpful for better usage of this enzyme for hyper-production of sugar alcohols by different industries.