Sample records for f1 interspecies hybrids

  1. Mechanisms Underlying Mammalian Hybrid Sterility in Two Feline Interspecies Models

    PubMed Central

    Davis, Brian W.; Seabury, Christopher M.; Brashear, Wesley A.; Li, Gang; Roelke-Parker, Melody; Murphy, William J.

    2015-01-01

    The phenomenon of male sterility in interspecies hybrids has been observed for over a century, however, few genes influencing this recurrent phenotype have been identified. Genetic investigations have been primarily limited to a small number of model organisms, thus limiting our understanding of the underlying molecular basis of this well-documented “rule of speciation.” We utilized two interspecies hybrid cat breeds in a genome-wide association study employing the Illumina 63 K single-nucleotide polymorphism array. Collectively, we identified eight autosomal genes/gene regions underlying associations with hybrid male sterility (HMS) involved in the function of the blood-testis barrier, gamete structural development, and transcriptional regulation. We also identified several candidate hybrid sterility regions on the X chromosome, with most residing in close proximity to complex duplicated regions. Differential gene expression analyses revealed significant chromosome-wide upregulation of X chromosome transcripts in testes of sterile hybrids, which were enriched for genes involved in chromatin regulation of gene expression. Our expression results parallel those reported in Mus hybrids, supporting the “Large X-Effect” in mammalian HMS and the potential epigenetic basis for this phenomenon. These results support the value of the interspecies feline model as a powerful tool for comparison to rodent models of HMS, demonstrating unique aspects and potential commonalities that underpin mammalian reproductive isolation. PMID:26006188

  2. Mechanisms Underlying Mammalian Hybrid Sterility in Two Feline Interspecies Models.

    PubMed

    Davis, Brian W; Seabury, Christopher M; Brashear, Wesley A; Li, Gang; Roelke-Parker, Melody; Murphy, William J

    2015-10-01

    The phenomenon of male sterility in interspecies hybrids has been observed for over a century, however, few genes influencing this recurrent phenotype have been identified. Genetic investigations have been primarily limited to a small number of model organisms, thus limiting our understanding of the underlying molecular basis of this well-documented "rule of speciation." We utilized two interspecies hybrid cat breeds in a genome-wide association study employing the Illumina 63 K single-nucleotide polymorphism array. Collectively, we identified eight autosomal genes/gene regions underlying associations with hybrid male sterility (HMS) involved in the function of the blood-testis barrier, gamete structural development, and transcriptional regulation. We also identified several candidate hybrid sterility regions on the X chromosome, with most residing in close proximity to complex duplicated regions. Differential gene expression analyses revealed significant chromosome-wide upregulation of X chromosome transcripts in testes of sterile hybrids, which were enriched for genes involved in chromatin regulation of gene expression. Our expression results parallel those reported in Mus hybrids, supporting the "Large X-Effect" in mammalian HMS and the potential epigenetic basis for this phenomenon. These results support the value of the interspecies feline model as a powerful tool for comparison to rodent models of HMS, demonstrating unique aspects and potential commonalities that underpin mammalian reproductive isolation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Morphological and molecular characterization of yellow oyster mushroom, Pleurotus citrinopileatus, hybrids obtained by interspecies mating.

    PubMed

    Rosnina, A G; Tan, Yee Shin; Abdullah, Noorlidah; Vikineswary, S

    2016-02-01

    Pleurotus citrinopileatus (yellow oyster mushroom) has an attractive shape and yellow colour but the fragile texture complicates packaging, and its strong aroma is unappealing to consumers. This study aimed to improve the characteristics and yield of P. citrinopileatus by interspecies mating between monokaryotic cultures of P. citrinopileatus and P. pulmonarius. Ten monokaryon cultures of the parental lines were crossed in all combinations to obtain hybrids. Eleven compatible mating pairs were obtained and cultivated to observe their sporophore morphology and yield. The selected hybrid, i.e. P1xC9, was beige in colour while hybrid P3xC8 was yellow in colour. Their sporophores had less offensive aroma, improved texture and higher yield. The DNA sequences of these hybrids were found to be in the same clade as the P. citrinopileatus parent with a bootstrap value of 99%. High bootstrap values indicate high genetic homology between hybrids and the P. citrinopileatus parent. The biological efficiencies of these hybrids P1xC9 (70.97%) and P3xC8 (52.14%) were also higher than the P. citrinopileatus parent (35.63%). Interspecies hybrids obtained by this mating technique can lead to better strains of mushrooms for genetic improvement of the Pleurotus species.

  4. Evolutionary Role of Interspecies Hybridization and Genetic Exchanges in Yeasts

    PubMed Central

    Dujon, Bernard

    2012-01-01

    Summary: Forced interspecific hybridization has been used in yeasts for many years to study speciation or to construct artificial strains with novel fermentative and metabolic properties. Recent genome analyses indicate that natural hybrids are also generated spontaneously between yeasts belonging to distinct species, creating lineages with novel phenotypes, varied genetic stability, or altered virulence in the case of pathogens. Large segmental introgressions from evolutionarily distant species are also visible in some yeast genomes, suggesting that interspecific genetic exchanges occur during evolution. The origin of this phenomenon remains unclear, but it is likely based on weak prezygotic barriers, limited Dobzhansky-Muller (DM) incompatibilities, and rapid clonal expansions. Newly formed interspecies hybrids suffer rapid changes in the genetic contribution of each parent, including chromosome loss or aneuploidy, translocations, and loss of heterozygosity, that, except in a few recently studied cases, remain to be characterized more precisely at the genomic level by use of modern technologies. We review here known cases of natural or artificially formed interspecies hybrids between yeasts and discuss their potential importance in terms of genome evolution. Problems of meiotic fertility, ploidy constraint, gene and gene product compatibility, and nucleomitochondrial interactions are discussed and placed in the context of other known mechanisms of yeast genome evolution as a model for eukaryotes. PMID:23204364

  5. Saccharomyces interspecies hybrids as model organisms for studying yeast adaptation to stressful environments.

    PubMed

    Lopandic, Ksenija

    2018-01-01

    The strong development of molecular biology techniques and next-generation sequencing technologies in the last two decades has significantly improved our understanding of the evolutionary history of Saccharomyces yeasts. It has been shown that many strains isolated from man-made environments are not pure genetic lines, but contain genetic materials from different species that substantially increase their genome complexity. A number of strains have been described as interspecies hybrids, implying different yeast species that under specific circumstances exchange and recombine their genomes. Such fusing usually results in a wide variety of alterations at the genetic and chromosomal levels. The observed changes have suggested a high genome plasticity and a significant role of interspecies hybridization in the adaptation of yeasts to environmental stresses and industrial processes. There is a high probability that harsh wine and beer fermentation environments, from which the majority of interspecies hybrids have been isolated so far, influence their selection and stabilization as well as their genomic and phenotypic heterogeneity. The lessons we have learned about geno- and phenotype plasticity and the diversity of natural and commercial yeast hybrids have already had a strong impact on the development of artificial hybrids that can be successfully used in the fermentation-based food and beverage industry. The creation of artificial hybrids through the crossing of strains with desired attributes is a possibility to obtain a vast variety of new, but not genetically modified yeasts with a range of improved and beneficial traits. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Does interspecies hybridization affect the host specificity of parasites in cyprinid fish?

    PubMed

    Simková, Andrea; Dávidová, Martina; Papoušek, Ivo; Vetešník, Lukáš

    2013-04-12

    Host specificity varies among parasite species. Some parasites are strictly host-specific, others show a specificity for congeneric or non-congeneric phylogenetically related host species, whilst some others are non-specific (generalists). Two cyprinids, Cyprinus carpio and Carassius gibelio, plus their respective hybrids were investigated for metazoan parasites. The aim of this study was to analyze whether interspecies hybridization affects host specificity. The different degrees of host specificity within a phylogenetic framework were taken into consideration (i.e. strict specialist, intermediate specialist, and intermediate generalist). Fish were collected during harvesting the pond and identified using meristic traits and molecular markers. Metazoan parasite species were collected. Host specificity of parasites was determined using the following classification: strict specialist, intermediate specialist, intermediate generalist and generalist. Parasite species richness was compared between parental species and their hybrids. The effect of host species on abundance of parasites differing in host specificity was tested. Hybrids harbored more different parasite species but their total parasite abundance was lower in comparison with parental species. Interspecies hybridization affected the host specificity of ecto- and endoparasites. Parasite species exhibiting different degrees of host specificity for C. carpio and C. gibelio were also present in hybrids. The abundance of strict specialists of C. carpio was significantly higher in parental species than in hybrids. Intermediate generalists parasitizing C. carpio and C. gibelio as two phylogenetically closely related host species preferentially infected C. gibelio when compared to C. carpio, based on prevalence and maximum intensity of infection. Hybrids were less infected by intermediate generalists when compared to C. gibelio. This finding does not support strict co-adaptation between host and parasite genotypes

  7. Allelic variants of hexose transporter Hxt3p and hexokinases Hxk1p/Hxk2p in strains of Saccharomyces cerevisiae and interspecies hybrids.

    PubMed

    Zuchowska, Magdalena; Jaenicke, Elmar; König, Helmut; Claus, Harald

    2015-11-01

    The transport of sugars across the plasma membrane is a critical step in the utilization of glucose and fructose by Saccharomyces cerevisiae during must fermentations. Variations in the molecular structure of hexose transporters and kinases may affect the ability of wine yeast strains to finish sugar fermentation, even under stressful wine conditions. In this context, we sequenced and compared genes encoding the hexose transporter Hxt3p and the kinases Hxk1p/Hxk2p of Saccharomyces strains and interspecies hybrids with different industrial usages and regional backgrounds. The Hxt3p primary structure varied in a small set of amino acids, which characterized robust yeast strains used for the production of sparkling wine or to restart stuck fermentations. In addition, interspecies hybrid strains, previously isolated at the end of spontaneous fermentations, revealed a common amino acid signature. The location and potential influence of the amino acids exchanges is discussed by means of a first modelled Hxt3p structure. In comparison, hexokinase genes were more conserved in different Saccharomyces strains and hybrids. Thus, molecular variants of the hexose carrier Hxt3p, but not of kinases, correlate with different fermentation performances of yeast. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Performance of interspecific F1 eucalypt hybrids in Zimbabwe

    Treesearch

    D. P. Gwaze; Floyd E. Bridgwater; W. J. Lowe

    2000-01-01

    Survival, growth 2nd stem straightness were assessed at 7 years of age for F1 hybrids of E. grandis with E. saligna, E. pellita and E. urophylla established at a high rainfall area, and the same traits were assessed at 6 years for F1 hybrids of

  9. Male sex interspecies divergence and down regulation of expression of spermatogenesis genes in Drosophila sterile hybrids.

    PubMed

    Sundararajan, Vignesh; Civetta, Alberto

    2011-01-01

    Male sex genes have shown a pattern of rapid interspecies divergence at both the coding and gene expression level. A common outcome from crosses between closely-related species is hybrid male sterility. Phenotypic and genetic studies in Drosophila sterile hybrid males have shown that spermatogenesis arrest is postmeiotic with few exceptions, and that most misregulated genes are involved in late stages of spermatogenesis. Comparative studies of gene regulation in sterile hybrids and parental species have mainly used microarrays providing a whole genome representation of regulatory problems in sterile hybrids. Real-time PCR studies can reject or reveal differences not observed in microarray assays. Moreover, differences in gene expression between samples can be dependant on the source of RNA (e.g., whole body vs. tissue). Here we survey expression in D. simulans, D. mauritiana and both intra and interspecies hybrids using a real-time PCR approach for eight genes expressed at the four main stages of sperm development. We find that all genes show a trend toward under expression in the testes of sterile hybrids relative to parental species with only the two proliferation genes (bam and bgcn) and the two meiotic class genes (can and sa) showing significant down regulation. The observed pattern of down regulation for the genes tested can not fully explain hybrid male sterility. We discuss the down regulation of spermatogenesis genes in hybrids between closely-related species within the contest of rapid divergence experienced by the male genome, hybrid sterility and possible allometric changes due to subtle testes-specific developmental abnormalities.

  10. Agronomic performance of F1, F2 and F3 hybrids between weedy rice and transgenic glufosinate-resistant rice.

    PubMed

    Song, Xiaoling; Wang, Zhou; Qiang, Sheng

    2011-08-01

    Studies of hybrid fitness, of which agronomic performance may be an indicator, can help in evaluating the potential for introgression of a transgene from a transgenic crop to wild relatives. The objective of this study was to assess the agronomic performance of reciprocal hybrids between two transgenic glufosinate-resistant rice lines, Y0003 and 99-t, and two weedy rice accessions, WR1 and WR2, in the greenhouse. F1 hybrids displayed heterosis in height, flag leaf area and number of spikelets per panicle. The agronomic performance of F1 between WR1 and Y0003 was not affected by crossing direction. The tiller and panicle numbers of F1 individuals were higher than their F2 counterparts. However, these traits did not change significantly from the F2 to the F3 generation or in hybrids with weedy rice as maternal or paternal plants. For all hybrids, the in vitro germination rates of fresh pollen were similar and significantly lower than those of their parents, seed sets were similar to or of lower value than those of weedy rice parents and seed shattering characteristics were partially suppressed, but the survival of hybrids over winter in the field was similar to that of weedy rice parents. All F1, F2 and F3 hybrids had similar composite agronomic performance to weedy rice parents. There was no significant decrease in the composite agronomic performance of any of the hybrids compared with weedy rice. This implies that gene flow from transgenic cultivated rice to weedy rice could occur under natural conditions. Copyright © 2011 Society of Chemical Industry.

  11. Cadmium accumulation characteristics of F1 hybrids by reciprocal hybridizing of Solanum nigrum in two climate-ecology regions.

    PubMed

    Lin, Lijin; He, Jing; Wang, Xun; Wang, Jin; Lv, Xiulan; Liao, Ming'an; Wang, Zhihui; Tang, Yi; Liang, Dong; Xia, Hui; Lai, Yunsong

    2016-09-01

    Different ecotypes of crop hybridization can produce heterosis effects and have wide applications in plant breeding. In this study, seedlings of cadmium (Cd) hyperaccumulator Solanum nigrum were collected from two different climate-ecology regions of the western Sichuan Basin, China, to carry out reciprocal hybridizing and to study the Cd accumulation characteristics of F1 hybrids of S. nigrum. In the two pot experiments (high and low soil Cd concentration), the biomass and Cd extraction of reciprocal hybridizing F1 hybrids were higher than those of the parents, but the Cd content in different organs was lower than those of the parents. These results indicate that the biomass and Cd extraction of F1 hybrids show over-parent heterosis, and the Cd content shows hybrid weakness. In the field experiment, the variety of the biomass, Cd content, and Cd extraction of reciprocal hybridizing F1 hybrids were the same as the pot experiments, and the Cd extraction by shoots of reciprocal hybridizing F1 hybrids increased by 17.20 and 23.08 %, relative to the two higher parents. Therefore, the reciprocal hybridizing S. nigrum of different climate-ecology regions could be efficiently used to improve the phytoremediation ability of S. nigrum to Cd-contaminated soil.

  12. Molecular Genetic Analysis of the Melanoma Regulatory locus in Xiphophorus Interspecies Hybrids

    PubMed Central

    Lu, Yuan; Boswell, Mikki; Boswell, William; Kneitz, Susanne; Hausmann, Michael; Klotz, Barbara; Regneri, Janine; Savage, Markita; Amores, Angel; Postlethwait, John; Warren, Wesley; Schartl, Manfred; Walter, Ronald

    2018-01-01

    Development of spontaneous melanoma in Xiphophorus interspecies backcross hybrid progeny, (X. hellerii × [X. maculatus Jp 163 A × X. hellerii]) is due to Mendelian segregation of a oncogene (xmrk) and a molecularly uncharacterized locus, called R(Diff), on LG5. R(Diff) is thought to suppresses the activity of xmrk in healthy X. maculatus Jp 163 A parental species that rarely develop melanoma. To better understand the molecular genetics of R(Diff), we utilized RNA-Seq to study allele-specific gene expression of spontaneous melanoma tumors and corresponding normal skin samples derived from 15 first generation backcross (BC1) hybrids and 13 fifth generation (BC5) hybrids. Allele-specific expression was determined for all genes and assigned to parental allele inheritance for each backcross hybrid individual. Results showed that genes residing in a 5.81 Mbp region on LG5 were exclusively expressed from the X. hellerii alleles in tumor-bearing BC1 hybrids. This observation indicates this region is consistently homozygous for X. hellerii alleles in tumor bearing animals, and therefore defines this region to be the R(Diff) locus. The R(Diff) locus harbors 164 gene models and includes the previously characterized R(Diff) candidate, cdkn2x. Twenty one genes in the R(Diff) region show differential expression in the tumor samples compared to normal skin tissue. These results further characterize the R(Diff) locus and suggest tumor suppression may require a multigenic region rather than a single gene variant. Differences in gene expression between tumor and normal skin tissue in this region may indicate interactions among several genes are required for backcross hybrid melanoma development. PMID:28345808

  13. Alternative Saccharomyces interspecies hybrid combinations and their potential for low‐temperature wort fermentation

    PubMed Central

    Nikulin, Jarkko; Krogerus, Kristoffer

    2017-01-01

    Abstract The lager yeast hybrid (Saccharomyces cerevisiae × Saccharomyces eubayanus) possesses two key characteristics that are essential for lager brewing: efficient sugar utilization and cold tolerance. Here we explore the possibility that the lager yeast phenotype can be recreated by hybridizing S. cerevisiae ale yeast with a number of cold‐tolerant Saccharomyces species including Saccharomyces arboricola, Saccharomyces eubayanus, Saccharomyces mikatae and Saccharomyces uvarum. Interspecies hybrids performed better than parental strains in lager brewing conditions (12°C and 12°P wort), with the S. mikatae hybrid performing as well as the S. eubayanus hybrid. Where the S. cerevisiae parent was capable of utilizing maltotriose, this trait was inherited by the hybrids. A greater production of higher alcohols and esters by the hybrids resulted in the production of more aromatic beers relative to the parents. Strong fermentation performance relative to the parents was dependent on ploidy, with polyploid hybrids (3n, 4n) performing better than diploid hybrids. All hybrids produced 4‐vinyl guaiacol, a smoke/clove aroma generally considered an off flavour in lager beer. This characteristic could however be eliminated by isolating spore clones from a fertile hybrid of S. cerevisiae and S. mikatae. The results suggest that S. eubayanus is dispensable when constructing yeast hybrids that express the typical lager yeast phenotype. © 2017 The Authors. Yeast published by John Wiley & Sons, Ltd. PMID:28755430

  14. Inheritance of Trans Chromosomal Methylation patterns from Arabidopsis F1 hybrids

    PubMed Central

    Greaves, Ian K.; Groszmann, Michael; Wang, Aihua; Peacock, W. James; Dennis, Elizabeth S.

    2014-01-01

    Hybridization in plants leads to transinteractions between the parental genomes and epigenomes that can result in changes to both 24 nt siRNA and cytosine methylation (mC) levels in the hybrid. In Arabidopsis the principle processes altering the hybrid methylome are Trans Chromosomal Methylation (TCM) and Trans Chromosomal deMethylation (TCdM) in which the mC pattern of a genomic segment attains the same mC pattern of the corresponding segment on the other parental chromosome. We examined two loci that undergo TCM/TCdM in the Arabidopsis C24/Landsberg erecta (Ler) F1 hybrids, which show patterns of inheritance dependent on the properties of the particular donor and recipient chromosomal segments. At At1g64790 the TCM- and TCdM-derived mC patterns are maintained in the F2 generation but are transmitted in outcrosses or backcrosses only by the C24 genomic segment. At a region between and adjacent to At3g43340 and At3g43350, the originally unmethylated Ler genomic segment receives the C24 mC pattern in the F1, which is then maintained in backcross plants independent of the presence of the parental C24 segment. In backcrosses to an unmethylated Ler allele, the newly methylated F1 Ler segment may act as a TCM source in a process comparable to paramutation in maize. TCM-derived mC patterns are associated with reduced expression of both At3g43340 and At3g43350 in F1 and F2 plants, providing support for such events influencing the transcriptome. The inheritance of the F1 mC patterns and the segregation of other genetic and epigenetic determinants may contribute to the reduced hybrid vigor in the F2 and subsequent generations. PMID:24449910

  15. Inheritance of Trans Chromosomal Methylation patterns from Arabidopsis F1 hybrids.

    PubMed

    Greaves, Ian K; Groszmann, Michael; Wang, Aihua; Peacock, W James; Dennis, Elizabeth S

    2014-02-04

    Hybridization in plants leads to transinteractions between the parental genomes and epigenomes that can result in changes to both 24 nt siRNA and cytosine methylation ((m)C) levels in the hybrid. In Arabidopsis the principle processes altering the hybrid methylome are Trans Chromosomal Methylation (TCM) and Trans Chromosomal deMethylation (TCdM) in which the (m)C pattern of a genomic segment attains the same (m)C pattern of the corresponding segment on the other parental chromosome. We examined two loci that undergo TCM/TCdM in the Arabidopsis C24/Landsberg erecta (Ler) F1 hybrids, which show patterns of inheritance dependent on the properties of the particular donor and recipient chromosomal segments. At At1g64790 the TCM- and TCdM-derived (m)C patterns are maintained in the F2 generation but are transmitted in outcrosses or backcrosses only by the C24 genomic segment. At a region between and adjacent to At3g43340 and At3g43350, the originally unmethylated Ler genomic segment receives the C24 (m)C pattern in the F1, which is then maintained in backcross plants independent of the presence of the parental C24 segment. In backcrosses to an unmethylated Ler allele, the newly methylated F1 Ler segment may act as a TCM source in a process comparable to paramutation in maize. TCM-derived (m)C patterns are associated with reduced expression of both At3g43340 and At3g43350 in F1 and F2 plants, providing support for such events influencing the transcriptome. The inheritance of the F1 (m)C patterns and the segregation of other genetic and epigenetic determinants may contribute to the reduced hybrid vigor in the F2 and subsequent generations.

  16. Spawning and fertility of F1 hybrids of the coral genus Acropora in the Indo-Pacific

    NASA Astrophysics Data System (ADS)

    Isomura, Naoko; Iwao, Kenji; Morita, Masaya; Fukami, Hironobu

    2016-09-01

    The role of hybridization through multi-specific synchronous spawning in the evolution of reef-building corals has been discussed since the 1990s, particularly for the genus Acropora. However, F1 hybrids have been reported as common in only one case in the Caribbean, with no evidence of mechanisms that would allow continuous reproduction of the hybrids. In this study, we report for the first time the fecundity of two F1 hybrid colonies produced experimentally from two Indo-Pacific species, A. intermedia and A. florida. These F1 hybrids spawned at the same time as the parental corals. Backcrossing and F1 hybrid crossing were successful in both directions. Furthermore, more than 90% self-fertilization was achieved in an F1 hybrid, although it was negligible in the parental corals. While it is possible that the F1 hybrid was a chimera, these results suggest that some products of interspecific hybridization may persist as the offspring of self-fertilizing F1 hybrids.

  17. Suppression of F1 Male-Specific Lethality in Caenorhabditis Hybrids by cbr-him-8.

    PubMed

    Ragavapuram, Vaishnavi; Hill, Emily Elaine; Baird, Scott Everet

    2015-12-31

    Haldane's Rule and Darwin's Corollary to Haldane's Rule are the observations that heterogametic F1 hybrids are frequently less fit than their homogametic siblings, and that asymmetric results are often obtained from reciprocal hybrid crosses. In Caenorhabditis, Haldane's Rule and Darwin's Corollary have been observed in several hybrid crosses, including crosses of Caenorhabditis briggsae and C. nigoni. Fertile F1 females are obtained from reciprocal crosses. However, F1 males obtained from C. nigoni mothers are sterile and F1 males obtained from C. briggsae die during embryogenesis. We have identified cbr-him-8 as a recessive maternal-effect suppressor of F1 hybrid male-specific lethality in this combination of species. This result implicates epigenetic meiotic silencing in the suppression of F1 male-specific lethality. It is also shown that F1 males bearing a C. briggsae X chromosome are fertile. When crossed to C. briggsae hermaphrodites or F1 females derived from C. briggsae hermaphrodites, viable F2 and backcross (B2) progeny were obtained. Sibling males that possessed a C. nigoni X chromosome were sterile. Therefore, the sterility of F1 males bearing a C. nigoni X chromosome must result from dysgenic interactions between the X chromosome of C. nigoni and the autosomes of C. briggsae. The fertility of F1 males bearing a C. briggsae X chromosome provides an opportunity to identify C. nigoni loci that prevent spermatogenesis, and hence hermaphroditic reproduction, in diplo-X hybrids. Copyright © 2016 Ragavapuram et al.

  18. Suppression of F1 Male-Specific Lethality in Caenorhabditis Hybrids by cbr-him-8

    PubMed Central

    Ragavapuram, Vaishnavi; Hill, Emily Elaine; Baird, Scott Everet

    2015-01-01

    Haldane’s Rule and Darwin’s Corollary to Haldane’s Rule are the observations that heterogametic F1 hybrids are frequently less fit than their homogametic siblings, and that asymmetric results are often obtained from reciprocal hybrid crosses. In Caenorhabditis, Haldane’s Rule and Darwin’s Corollary have been observed in several hybrid crosses, including crosses of Caenorhabditis briggsae and C. nigoni. Fertile F1 females are obtained from reciprocal crosses. However, F1 males obtained from C. nigoni mothers are sterile and F1 males obtained from C. briggsae die during embryogenesis. We have identified cbr-him-8 as a recessive maternal-effect suppressor of F1 hybrid male-specific lethality in this combination of species. This result implicates epigenetic meiotic silencing in the suppression of F1 male-specific lethality. It is also shown that F1 males bearing a C. briggsae X chromosome are fertile. When crossed to C. briggsae hermaphrodites or F1 females derived from C. briggsae hermaphrodites, viable F2 and backcross (B2) progeny were obtained. Sibling males that possessed a C. nigoni X chromosome were sterile. Therefore, the sterility of F1 males bearing a C. nigoni X chromosome must result from dysgenic interactions between the X chromosome of C. nigoni and the autosomes of C. briggsae. The fertility of F1 males bearing a C. briggsae X chromosome provides an opportunity to identify C. nigoni loci that prevent spermatogenesis, and hence hermaphroditic reproduction, in diplo-X hybrids. PMID:26721896

  19. Genome sequence of the lager brewing yeast, an interspecies hybrid.

    PubMed

    Nakao, Yoshihiro; Kanamori, Takeshi; Itoh, Takehiko; Kodama, Yukiko; Rainieri, Sandra; Nakamura, Norihisa; Shimonaga, Tomoko; Hattori, Masahira; Ashikari, Toshihiko

    2009-04-01

    This work presents the genome sequencing of the lager brewing yeast (Saccharomyces pastorianus) Weihenstephan 34/70, a strain widely used in lager beer brewing. The 25 Mb genome comprises two nuclear sub-genomes originating from Saccharomyces cerevisiae and Saccharomyces bayanus and one circular mitochondrial genome originating from S. bayanus. Thirty-six different types of chromosomes were found including eight chromosomes with translocations between the two sub-genomes, whose breakpoints are within the orthologous open reading frames. Several gene loci responsible for typical lager brewing yeast characteristics such as maltotriose uptake and sulfite production have been increased in number by chromosomal rearrangements. Despite an overall high degree of conservation of the synteny with S. cerevisiae and S. bayanus, the syntenies were not well conserved in the sub-telomeric regions that contain lager brewing yeast characteristic and specific genes. Deletion of larger chromosomal regions, a massive unilateral decrease of the ribosomal DNA cluster and bilateral truncations of over 60 genes reflect a post-hybridization evolution process. Truncations and deletions of less efficient maltose and maltotriose uptake genes may indicate the result of adaptation to brewing. The genome sequence of this interspecies hybrid yeast provides a new tool for better understanding of lager brewing yeast behavior in industrial beer production.

  20. Genome Sequence of the Lager Brewing Yeast, an Interspecies Hybrid

    PubMed Central

    Nakao, Yoshihiro; Kanamori, Takeshi; Itoh, Takehiko; Kodama, Yukiko; Rainieri, Sandra; Nakamura, Norihisa; Shimonaga, Tomoko; Hattori, Masahira; Ashikari, Toshihiko

    2009-01-01

    This work presents the genome sequencing of the lager brewing yeast (Saccharomyces pastorianus) Weihenstephan 34/70, a strain widely used in lager beer brewing. The 25 Mb genome comprises two nuclear sub-genomes originating from Saccharomyces cerevisiae and Saccharomyces bayanus and one circular mitochondrial genome originating from S. bayanus. Thirty-six different types of chromosomes were found including eight chromosomes with translocations between the two sub-genomes, whose breakpoints are within the orthologous open reading frames. Several gene loci responsible for typical lager brewing yeast characteristics such as maltotriose uptake and sulfite production have been increased in number by chromosomal rearrangements. Despite an overall high degree of conservation of the synteny with S. cerevisiae and S. bayanus, the syntenies were not well conserved in the sub-telomeric regions that contain lager brewing yeast characteristic and specific genes. Deletion of larger chromosomal regions, a massive unilateral decrease of the ribosomal DNA cluster and bilateral truncations of over 60 genes reflect a post-hybridization evolution process. Truncations and deletions of less efficient maltose and maltotriose uptake genes may indicate the result of adaptation to brewing. The genome sequence of this interspecies hybrid yeast provides a new tool for better understanding of lager brewing yeast behavior in industrial beer production. PMID:19261625

  1. Evolutionary Analysis of Heterochromatin Protein Compatibility by Interspecies Complementation in Saccharomyces

    PubMed Central

    Zill, Oliver A.; Scannell, Devin R.; Kuei, Jeffrey; Sadhu, Meru; Rine, Jasper

    2012-01-01

    The genetic bases for species-specific traits are widely sought, but reliable experimental methods with which to identify functionally divergent genes are lacking. In the Saccharomyces genus, interspecies complementation tests can be used to evaluate functional conservation and divergence of biological pathways or networks. Silent information regulator (SIR) proteins in S. bayanus provide an ideal test case for this approach because they show remarkable divergence in sequence and paralog number from those found in the closely related S. cerevisiae. We identified genes required for silencing in S. bayanus using a genetic screen for silencing-defective mutants. Complementation tests in interspecies hybrids identified an evolutionarily conserved Sir-protein-based silencing machinery, as defined by two interspecies complementation groups (SIR2 and SIR3). However, recessive mutations in S. bayanus SIR4 isolated from this screen could not be complemented by S. cerevisiae SIR4, revealing species-specific functional divergence in the Sir4 protein despite conservation of the overall function of the Sir2/3/4 complex. A cladistic complementation series localized the occurrence of functional changes in SIR4 to the S. cerevisiae and S. paradoxus branches of the Saccharomyces phylogeny. Most of this functional divergence mapped to sequence changes in the Sir4 PAD. Finally, a hemizygosity modifier screen in the interspecies hybrids identified additional genes involved in S. bayanus silencing. Thus, interspecies complementation tests can be used to identify (1) mutations in genetically underexplored organisms, (2) loci that have functionally diverged between species, and (3) evolutionary events of functional consequence within a genus. PMID:22923378

  2. Hemodynamic (fNIRS) and EEG (N200) correlates of emotional inter-species interactions modulated by visual and auditory stimulation

    PubMed Central

    Balconi, Michela; Vanutelli, Maria Elide

    2016-01-01

    The brain activity, considered in its hemodynamic (optical imaging: functional Near-Infrared Spectroscopy, fNIRS) and electrophysiological components (event-related potentials, ERPs, N200) was monitored when subjects observed (visual stimulation, V) or observed and heard (visual + auditory stimulation, VU) situations which represented inter-species (human-animal) interactions, with an emotional positive (cooperative) or negative (uncooperative) content. In addition, the cortical lateralization effect (more left or right dorsolateral prefrontal cortex, DLPFC) was explored. Both ERP and fNIRS showed significant effects due to emotional interactions which were discussed at light of cross-modal integration effects. The significance of inter-species effect for the emotional behavior was considered. In addition, hemodynamic and EEG consonant results and their value as integrated measures were discussed at light of valence effect. PMID:26976052

  3. Developmental trajectories and breakdown in F1 interpopulation hybrids of Tribolium castaneum

    PubMed Central

    Drury, Douglas W; Ehmke, Ross C; Jideonwo, Victoria N; Wade, Michael J

    2013-01-01

    When hybrid inviability is an indirect by-product of local adaptation, we expect its degree of severity between pairs of populations to vary and to be sensitive to the environment. While complete reciprocal hybrid inviability is the outcome of the gradual process of local adaptation, it is not representative of the process of accumulation of incompatibility. In the flour beetle, Tribolium castaneum, some pairs of populations exhibit complete, reciprocal F1 hybrid incompatibility while other pairs are fully or partially compatible. We characterize this naturally occurring variation in the degree and timing of expression of the hybrid incompatible phenotype to better understand the number of genes or developmental processes contributing to speciation. We assessed the morphological and developmental variation in four Tribolium castaneum populations and their 12 possible F1 hybrids at each life-history stage from egg to adult. We find that the rate of hybrid larval development is affected in all interpopulation crosses, including those eventually producing viable, fertile adults. Hybrid incompatibility manifests early in development as changes in the duration of instars and diminished success in the transition between instars are relative to the parent populations. Parent populations with similar developmental profiles may produce hybrids with disrupted development. The degree and timing of expression of hybrid inviability depends upon populations crossed, direction of the cross, and environment in which hybrids are raised. Our findings suggest that the coordinated expression of genes involved in transitional periods of development is the underlying cause of hybrid incompatibility in this species. PMID:23919145

  4. Dissecting the genetic architecture of F1 hybrid sterility in house mice.

    PubMed

    Dzur-Gejdosova, Maria; Simecek, Petr; Gregorova, Sona; Bhattacharyya, Tanmoy; Forejt, Jiri

    2012-11-01

    Hybrid sterility as a postzygotic reproductive isolation mechanism has been studied for over 80 years, yet the first identifications of hybrid sterility genes in Drosophila and mouse are quite recent. To study the genetic architecture of F(1) hybrid sterility between young subspecies of house mouse Mus m. domesticus and M. m. musculus, we conducted QTL analysis of a backcross between inbred strains representing these two subspecies and probed the role of individual chromosomes in hybrid sterility using the intersubspecific chromosome substitution strains. We provide direct evidence that the asymmetry in male infertility between reciprocal crosses is conferred by the middle region of M. m. musculus Chr X, thus excluding other potential candidates such as Y, imprinted genes, and mitochondrial DNA. QTL analysis identified strong hybrid sterility loci on Chr 17 and Chr X and predicted a set of interchangeable autosomal loci, a subset of which is sufficient to activate the Dobzhansky-Muller incompatibility of the strong loci. Overall, our results indicate the oligogenic nature of F(1) hybrid sterility, which should be amenable to reconstruction by proper combination of chromosome substitution strains. Such a prefabricated model system should help to uncover the gene networks and molecular mechanisms underlying hybrid sterility. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  5. Genetic architecture of hybrid male sterility in Drosophila: analysis of intraspecies variation for interspecies isolation.

    PubMed

    Reed, Laura K; LaFlamme, Brooke A; Markow, Therese A

    2008-08-27

    The genetic basis of postzygotic isolation is a central puzzle in evolutionary biology. Evolutionary forces causing hybrid sterility or inviability act on the responsible genes while they still are polymorphic, thus we have to study these traits as they arise, before isolation is complete. Isofemale strains of D. mojavensis vary significantly in their production of sterile F(1) sons when females are crossed to D. arizonae males. We took advantage of the intraspecific polymorphism, in a novel design, to perform quantitative trait locus (QTL) mapping analyses directly on F(1) hybrid male sterility itself. We found that the genetic architecture of the polymorphism for hybrid male sterility (HMS) in the F(1) is complex, involving multiple QTL, epistasis, and cytoplasmic effects. The role of extensive intraspecific polymorphism, multiple QTL, and epistatic interactions in HMS in this young species pair shows that HMS is arising as a complex trait in this system. Directional selection alone would be unlikely to maintain polymorphism at multiple loci, thus we hypothesize that directional selection is unlikely to be the only evolutionary force influencing postzygotic isolation.

  6. Asymmetric hybridization in Rhododendron agastum: a hybrid taxon comprising mainly F1s in Yunnan, China

    PubMed Central

    Zha, Hong-Guang; Milne, Richard I.; Sun, Hang

    2010-01-01

    Background and Aims Rhododendron (Ericaceae) is a large woody genus in which hybridization is thought to play an important role in evolution and speciation, particularly in the Sino-Himalaya region where many interfertile species often occur sympatrically. Rhododendron agastum, a putative hybrid species, occurs in China, western Yunnan Province, in mixed populations with R. irroratum and R. delavayi. Methods Material of these taxa from two sites 400 km apart (ZhuJianYuan, ZJY and HuaDianBa, HDB) was examined using cpDNA and internal transcribed spacer (ITS) sequences, and amplified fragment length polymorphism (AFLP) loci, to test the possibility that R. agastum was in fact a hybrid between two of the other species. Chloroplast trnL-F and trnS-trnG sequences together distinguished R. irroratum, R. delavayi and some material of R. decorum, which is also considered a putative parent of R. agastum. Key Results All 14 R. agastum plants from the HDB site had the delavayi cpDNA haplotype, whereas at the ZJY site 17 R. agastum plants had this haplotype and four had the R. irroratum haplotype. R. irroratum and R. delavayi are distinguished by five unequivocal point mutations in their ITS sequences; every R. agastum accession had an additive pattern (double peaks) at each of these sites. Data from AFLP loci were acquired for between ten and 21 plants of each taxon from each site, and were analysed using a Bayesian approach implemented by the program NewHybrids. The program confirmed the identity of all accessions of R. delavayi, and all R. irroratum except one, which was probably a backcross. All R. agastum from HDB and 19 of 21 from ZJY were classified as F1 hybrids; the other two could not be assigned a class. Conclusions Rhododendron agastum represents populations of hybrids between R. irroratum and R. delavayi, which comprise mostly or only F1s, at the two sites examined. The sites differ in that at HDB there was no detected variation in cpDNA type or hybrid class

  7. Genetic Architecture of Hybrid Male Sterility in Drosophila: Analysis of Intraspecies Variation for Interspecies Isolation

    PubMed Central

    Reed, Laura K.; LaFlamme, Brooke A.; Markow, Therese A.

    2008-01-01

    Background The genetic basis of postzygotic isolation is a central puzzle in evolutionary biology. Evolutionary forces causing hybrid sterility or inviability act on the responsible genes while they still are polymorphic, thus we have to study these traits as they arise, before isolation is complete. Methodology/Principal Findings Isofemale strains of D. mojavensis vary significantly in their production of sterile F1 sons when females are crossed to D. arizonae males. We took advantage of the intraspecific polymorphism, in a novel design, to perform quantitative trait locus (QTL) mapping analyses directly on F1 hybrid male sterility itself. We found that the genetic architecture of the polymorphism for hybrid male sterility (HMS) in the F1 is complex, involving multiple QTL, epistasis, and cytoplasmic effects. Conclusions/Significance The role of extensive intraspecific polymorphism, multiple QTL, and epistatic interactions in HMS in this young species pair shows that HMS is arising as a complex trait in this system. Directional selection alone would be unlikely to maintain polymorphism at multiple loci, thus we hypothesize that directional selection is unlikely to be the only evolutionary force influencing postzygotic isolation. PMID:18728782

  8. Widespread Over-Expression of the X Chromosome in Sterile F1 Hybrid Mice

    PubMed Central

    Good, Jeffrey M.; Giger, Thomas; Dean, Matthew D.; Nachman, Michael W.

    2010-01-01

    The X chromosome often plays a central role in hybrid male sterility between species, but it is unclear if this reflects underlying regulatory incompatibilities. Here we combine phenotypic data with genome-wide expression data to directly associate aberrant expression patterns with hybrid male sterility between two species of mice. We used a reciprocal cross in which F1 males are sterile in one direction and fertile in the other direction, allowing us to associate expression differences with sterility rather than with other hybrid phenotypes. We found evidence of extensive over-expression of the X chromosome during spermatogenesis in sterile but not in fertile F1 hybrid males. Over-expression was most pronounced in genes that are normally expressed after meiosis, consistent with an X chromosome-wide disruption of expression during the later stages of spermatogenesis. This pattern was not a simple consequence of faster evolutionary divergence on the X chromosome, because X-linked expression was highly conserved between the two species. Thus, transcriptional regulation of the X chromosome during spermatogenesis appears particularly sensitive to evolutionary divergence between species. Overall, these data provide evidence for an underlying regulatory basis to reproductive isolation in house mice and underscore the importance of transcriptional regulation of the X chromosome to the evolution of hybrid male sterility. PMID:20941395

  9. Selection against recombinant hybrids maintains reproductive isolation in hybridizing Populus species despite F1 fertility and recurrent gene flow.

    PubMed

    Christe, Camille; Stölting, Kai N; Bresadola, Luisa; Fussi, Barbara; Heinze, Berthold; Wegmann, Daniel; Lexer, Christian

    2016-06-01

    Natural hybrid zones have proven to be precious tools for understanding the origin and maintenance of reproductive isolation (RI) and therefore species. Most available genomic studies of hybrid zones using whole- or partial-genome resequencing approaches have focused on comparisons of the parental source populations involved in genome admixture, rather than exploring fine-scale patterns of chromosomal ancestry across the full admixture gradient present between hybridizing species. We have studied three well-known European 'replicate' hybrid zones of Populus alba and P. tremula, two widespread, ecologically divergent forest trees, using up to 432 505 single-nucleotide polymorphisms (SNPs) from restriction site-associated DNA (RAD) sequencing. Estimates of fine-scale chromosomal ancestry, genomic divergence and differentiation across all 19 poplar chromosomes revealed strikingly contrasting results, including an unexpected preponderance of F1 hybrids in the centre of genomic clines on the one hand, and genomically localized, spatially variable shared variants consistent with ancient introgression between the parental species on the other. Genetic ancestry had a significant effect on survivorship of hybrid seedlings in a common garden trial, pointing to selection against early-generation recombinants. Our results indicate a role for selection against recombinant genotypes in maintaining RI in the face of apparent F1 fertility, consistent with the intragenomic 'coadaptation' model of barriers to introgression upon secondary contact. Whole-genome resequencing of hybridizing populations will clarify the roles of specific genetic pathways in RI between these model forest trees and may reveal which loci are affected most strongly by its cyclic breakdown. © 2016 John Wiley & Sons Ltd.

  10. A novel approach identifying hybrid sterility QTL on the autosomes of Drosophila simulans and D. mauritiana.

    PubMed

    Dickman, Christopher T D; Moehring, Amanda J

    2013-01-01

    When species interbreed, the hybrid offspring that are produced are often sterile. If only one hybrid sex is sterile, it is almost always the heterogametic (XY or ZW) sex. Taking this trend into account, the predominant model used to explain the genetic basis of F1 sterility involves a deleterious interaction between recessive sex-linked loci from one species and dominant autosomal loci from the other species. This model is difficult to evaluate, however, as only a handful of loci influencing interspecies hybrid sterility have been identified, and their autosomal genetic interactors have remained elusive. One hindrance to their identification has been the overwhelming effect of the sex chromosome in mapping studies, which could 'mask' the ability to accurately map autosomal factors. Here, we use a novel approach employing attached-X chromosomes to create reciprocal backcross interspecies hybrid males that have a non-recombinant sex chromosome and recombinant autosomes. The heritable variation in phenotype is thus solely caused by differences in the autosomes, thereby allowing us to accurately identify the number and location of autosomal sterility loci. In one direction of backcross, all males were sterile, indicating that sterility could be entirely induced by the sex chromosome complement in these males. In the other direction, we identified nine quantitative trait loci that account for a surprisingly large amount (56%) of the autosome-induced phenotypic variance in sterility, with a large contribution of autosome-autosome epistatic interactions. These loci are capable of acting dominantly, and thus could contribute to F1 hybrid sterility.

  11. Selective Somatic Elimination of NICOTIANA GLUTINOSA Chromosomes in the F(1) Hybrids of N. SUAVEOLENS and N. GLUTINOSA.

    PubMed

    Gupta, S B; Gupta, P

    1973-04-01

    The F(1) hybrids of Nicotiana suaveolens (subgenus Petunioides, 2n = 32) and N. glutinosa (subgenus Tabacum, 2n = 24), were examined during their development, from seedlings to mature plants. It was observed that in the hybrids, there was a progressive change of dominant N. glutinosa morphological characteristics towards those of N. suaveolens, in leaf shape, stem, flower color and branching pattern. A study of mitotic chromosomes in the root-tips and in very young anthers of the mature plants indicated a significantly high average frequency of aberrant mitotic anaphases (bridges and fragments, 12% and 11% respectively). As a consequence of this phenomenon, variability in the number and size of chromosomes was observed in the PMC's and in mitotic metaphases (29-24 chromosomes). In order to establish whether the N. glutinosa chromosomes were preferentially lost, a karyological study of the parents and their F(1) hybrids was carried out and it was established that the F(1) hybrids were losing N. glutinosa chromosomes preferentially. A mechanism was suggested for the loss of these chromosomes by means of a chromatid type of breakage-fusion-bridge cycle (b-f-b cycle) and initiation of the b-f-b cycle in the hybrid due to an interaction of the regulatory mechanism of DNA replication in the haploid genomes of the parental species. However, loss of these chromosomes owing to interaction of certain genes from the two parental species cannot be ruled out.

  12. Misregulation of Gene Expression and Sterility in Interspecies Hybrids: Causal Links and Alternative Hypotheses.

    PubMed

    Civetta, Alberto

    2016-05-01

    Understanding the origin of species is of interest to biologist in general and evolutionary biologist in particular. Hybrid male sterility (HMS) has been a focus in studies of speciation because sterility imposes a barrier to free gene flow between organisms, thus effectively isolating them as distinct species. In this review, I focus on the role of differential gene expression in HMS and speciation. Microarray and qPCR assays have established associations between misregulation of gene expression and sterility in hybrids between closely related species. These studies originally proposed disrupted expression of spermatogenesis genes as a causative of sterility. Alternatively, rapid genetic divergence of regulatory elements, particularly as they relate to the male sex (fast-male evolution), can drive the misregulation of sperm developmental genes in the absence of sterility. The use of fertile hybrids (both backcross and F1 progeny) as controls has lent support to this alternative explanation. Differences in gene expression between fertile and sterile hybrids can also be influenced by a pattern of faster evolution of the sex chromosome (fast-X evolution) than autosomes. In particular, it would be desirable to establish whether known X-chromosome sterility factors can act as trans-regulatory drivers of genome-wide patterns of misregulation. Genome-wide expression studies coupled with assays of proxies of sterility in F1 and BC progeny have identified candidate HMS genes but functional assays, and a better phenotypic characterization of sterility phenotypes, are needed to rigorously test how these genes might contribute to HMS.

  13. Cadmium accumulation characteristics of low-cadmium rice (Oryza sativa L.) line and F1 hybrids grown in cadmium-contaminated soils.

    PubMed

    Li, Kun; Yu, Haiying; Li, Tingxuan; Chen, Guangdeng; Huang, Fu

    2017-07-01

    Cadmium (Cd) pollution has threatened severely to food safety and human health. A pot experiment and a field experiment were conducted to investigate the difference of Cd accumulation between rice (Oryza sativa L.) lines and F 1 hybrids in Cd-contaminated soils. The adverse effect on biomass of rice lines was greater than that of F 1 hybrids under Cd treatments in the pot experiment. The variations of Cd concentration among rice cultivars in different organs were smaller in stem and leaf, but larger in root and ear. Average proportion of Cd in root of F 1 hybrids was 1.39, 1.39, and 1.16 times higher than those of rice lines at the treatment of 1, 2, and 4 mg Cd kg -1 soil, respectively. Cd concentrations in ear of F 1 hybrids were significantly lower than rice lines with the reduction from 29.24 to 50.59%. Cd concentrations in brown rice of all F 1 hybrids were less than 0.2 mg kg -1 at 1 mg Cd kg -1 soil, in which Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be screened out as cadmium-safe cultivars (CSCs) for being safe even at 2 mg Cd kg -1 soil. C268A/YaHui2816 showed the lowest Cd concentration in root among F 1 hybrids, while Lu98A/YaHui2816 and 5406A/YaHui2816 showed lower capability of Cd translocation from root to shoot under Cd exposure, which eventually caused the lower Cd accumulation in brown rice. The lower level of Cd translocation contributed to reducing the accumulation of Cd in brown rice had been validated by the field experiment. Thus, Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be considered as potential CSCs to cultivate in Cd-contaminated soils (<2 mg Cd kg -1 soil).

  14. [Process of meiosis in interspecific hybrid F1 Lycopersicon esculentum Mill. x Lycopersicon chilense Dun].

    PubMed

    Montvid, P Iu; Samovol, O P; Miroshnychenko, V P

    2011-01-01

    The investigation concerns meiosis behaviour in embryo-culture-obtained Lycopersicon esculentum Mill. (mutant seedline Mo 638) x L. chilense Dun. F1 hybrid and its parental forms. It was determined that chiasma frequency decreased while univalent and meiotic disorder frequencies increased in F1 plants in comparison with parents forms. Univalent number and the percent of main disorders lowered with bud tier increasing. The conclusion was made about meiosis regularity connection with the influence of environment factors and heterozygous genotype of F1 plants Lycopersicon esculentum x L. chilense.

  15. ‘Caro-Tex 312’, a high yielding, orange-fruited, Habanero-type, F1 hybrid pepper

    USDA-ARS?s Scientific Manuscript database

    The Agricultural Research Service of the U. S. Department of Agriculture and the College of Agriculture and Life Sciences of Texas A&M University have released the high yielding, orange-fruited, Habanero-type, F1 hybrid pepper cultivar CaroTex-312. CaroTex-312 is the result of an F1 cross made at C...

  16. Twenty-four-nucleotide siRNAs produce heritable trans-chromosomal methylation in F1 Arabidopsis hybrids.

    PubMed

    Greaves, Ian K; Eichten, Steven R; Groszmann, Michael; Wang, Aihua; Ying, Hua; Peacock, W James; Dennis, Elizabeth S

    2016-11-01

    Hybrid Arabidopsis plants undergo epigenetic reprogramming producing decreased levels of 24-nt siRNAs and altered patterns of DNA methylation that can affect gene expression. Driving the changes in methylation are the processes trans-chromosomal methylation (TCM) and trans-chromosomal demethylation (TCdM). In TCM/TCdM the methylation state of one allele is altered to resemble the other allele. We show that Pol IV-dependent sRNAs are required to establish TCM events. The changes in DNA methylation and the associated changes in sRNA levels in the F1 hybrid can be maintained in subsequent generations and affect hundreds of regions in the F2 epigenome. The inheritance of these altered epigenetic states varies in F2 individuals, resulting in individuals with genetically identical loci displaying different epigenetic states and gene expression profiles. The change in methylation at these regions is associated with the presence of sRNAs. Loci without any sRNA activity can have altered methylation states, suggesting that a sRNA-independent mechanism may also contribute to the altered methylation state of the F1 and F2 generations.

  17. Twenty-four–nucleotide siRNAs produce heritable trans-chromosomal methylation in F1 Arabidopsis hybrids

    PubMed Central

    Greaves, Ian K.; Eichten, Steven R.; Groszmann, Michael; Wang, Aihua; Ying, Hua; Peacock, W. James; Dennis, Elizabeth S.

    2016-01-01

    Hybrid Arabidopsis plants undergo epigenetic reprogramming producing decreased levels of 24-nt siRNAs and altered patterns of DNA methylation that can affect gene expression. Driving the changes in methylation are the processes trans-chromosomal methylation (TCM) and trans-chromosomal demethylation (TCdM). In TCM/TCdM the methylation state of one allele is altered to resemble the other allele. We show that Pol IV-dependent sRNAs are required to establish TCM events. The changes in DNA methylation and the associated changes in sRNA levels in the F1 hybrid can be maintained in subsequent generations and affect hundreds of regions in the F2 epigenome. The inheritance of these altered epigenetic states varies in F2 individuals, resulting in individuals with genetically identical loci displaying different epigenetic states and gene expression profiles. The change in methylation at these regions is associated with the presence of sRNAs. Loci without any sRNA activity can have altered methylation states, suggesting that a sRNA-independent mechanism may also contribute to the altered methylation state of the F1 and F2 generations. PMID:27791153

  18. USE OF INTERSPECIES CORRELATION ESTIMATIONS TO PREDICT HC5'S BASED ON MINIMAL DATA

    EPA Science Inventory

    Dyer, S., S. Belanger, J. Chaney, D. Versteeg and F. Mayer. In press. Use of Interspecies Correlation Estimations to Predict HC5's Based on Minimal Data (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November 2004, Portland, OR. 1 p. (ERL,GB R1013).

  19. Comparative proteome analysis of drought-sensitive and drought-tolerant rapeseed roots and their hybrid F1 line under drought stress.

    PubMed

    Mohammadi, Payam Pour; Moieni, Ahmad; Komatsu, Setsuko

    2012-11-01

    Rapeseed (Brassica napus L.), which is the third leading source of vegetable oil, is sensitive to drought stress during the early vegetative growth stage. To investigate the initial response of rapeseed to drought stress, changes in the protein expression profiles of drought-sensitive (RGS-003) and drought-tolerant lines (SLM-003), and their F1 hybrid, were analyzed using a proteomics approach. Seven-day-old rapeseed seedlings were treated with drought stress by restricting water for 7 days, and proteins were extracted from roots and separated by two-dimensional polyacrylamide gel electrophoresis. In the sensitive rapeseed line, 35 protein spots were differentially expressed under drought stress, and proteins related to metabolism, energy, disease/defense, and transport were decreased. In the tolerant line, 32 protein spots were differentially expressed under drought stress, and proteins involved in metabolism, disease/defense, and transport were increased, while energy-related proteins were decreased. Six protein spots in F1 hybrid were common among expressed proteins in the drought-sensitive and -tolerant lines. Notably, tubulin beta-2 and heat shock protein 70 were decreased in the drought-sensitive line and hybrid F1 plants, while jasmonate-inducible protein and 20S proteasome subunit PAF1 were increased in the F1 hybrids and drought-tolerant line. These results indicate that (1) V-type H(+) ATPase, plasma-membrane associated cation-binding protein, HSP 90, and elongation factor EF-2 have a role in the drought tolerance of rapeseed; (2) The decreased levels of heat shock protein 70 and tubulin beta-2 in the drought-sensitive and hybrid F1 lines might explain the reduced growth of these lines in drought conditions.

  20. Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

    PubMed

    He, J H; Shahid, M Q; Li, Y J; Guo, H B; Cheng, X A; Liu, X D; Lu, Y G

    2011-08-01

    The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. © 2011 The Author(s).

  1. Design of an F1 hybrid breeding strategy for ryegrasses based on selection of self-incompatibility locus-specific alleles

    PubMed Central

    Pembleton, Luke W.; Shinozuka, Hiroshi; Wang, Junping; Spangenberg, German C.; Forster, John W.; Cogan, Noel O. I.

    2015-01-01

    Relatively modest levels of genetic gain have been achieved in conventional ryegrass breeding when compared to cereal crops such as maize, current estimates indicating an annual improvement of 0.25–0.6% in dry matter production. This property is partially due to an inability to effectively exploit heterosis through the formation of F1 hybrids. Controlled crossing of ryegrass lines from geographically distant origins has demonstrated the occurrence of heterosis, which can result in increases of dry matter production in the order of 25%. Although capture of hybrid vigor offers obvious advantages for ryegrass cultivar production, to date there have been no effective and commercially suitable methods for obtaining high proportions of F1 hybrid seed. Continued advances in fine-scale genetic and physical mapping of the gametophytic self-incompatibility (SI) loci (S and Z) of ryegrasses are likely in the near future to permit the identification of closely linked genetic markers that define locus-specific haplotypes, allowing prediction of allelic variants and hence compatibility between different plant genotypes. Given the availability of such information, a strategy for efficient generation of ryegrass cultivars with a high proportion of F1 hybrid individuals has been simulated, which is suitable for commercial implementation. Through development of two parental pools with restricted diversity at the SI loci, relative crossing compatibility between pools is increased. Based on simulation of various levels of SI allele diversity restriction, the most effective scheme will generate 83.33% F1 hybrids. Results from the study, including the impact of varying flowering time, are discussed along with a proposed breeding design for commercial application. PMID:26442077

  2. Hybrid mimics and hybrid vigor in Arabidopsis

    PubMed Central

    Wang, Li; Greaves, Ian K.; Groszmann, Michael; Wu, Li Min; Dennis, Elizabeth S.; Peacock, W. James

    2015-01-01

    F1 hybrids can outperform their parents in yield and vegetative biomass, features of hybrid vigor that form the basis of the hybrid seed industry. The yield advantage of the F1 is lost in the F2 and subsequent generations. In Arabidopsis, from F2 plants that have a F1-like phenotype, we have by recurrent selection produced pure breeding F5/F6 lines, hybrid mimics, in which the characteristics of the F1 hybrid are stabilized. These hybrid mimic lines, like the F1 hybrid, have larger leaves than the parent plant, and the leaves have increased photosynthetic cell numbers, and in some lines, increased size of cells, suggesting an increased supply of photosynthate. A comparison of the differentially expressed genes in the F1 hybrid with those of eight hybrid mimic lines identified metabolic pathways altered in both; these pathways include down-regulation of defense response pathways and altered abiotic response pathways. F6 hybrid mimic lines are mostly homozygous at each locus in the genome and yet retain the large F1-like phenotype. Many alleles in the F6 plants, when they are homozygous, have expression levels different to the level in the parent. We consider this altered expression to be a consequence of transregulation of genes from one parent by genes from the other parent. Transregulation could also arise from epigenetic modifications in the F1. The pure breeding hybrid mimics have been valuable in probing the mechanisms of hybrid vigor and may also prove to be useful hybrid vigor equivalents in agriculture. PMID:26283378

  3. Tissue culture-induced genetic and epigenetic alterations in rice pure-lines, F1 hybrids and polyploids

    PubMed Central

    2013-01-01

    Background Genetic and epigenetic alterations can be invoked by plant tissue culture, which may result in heritable changes in phenotypes, a phenomenon collectively termed somaclonal variation. Although extensive studies have been conducted on the molecular nature and spectrum of tissue culture-induced genomic alterations, the issue of whether and to what extent distinct plant genotypes, e.g., pure-lines, hybrids and polyploids, may respond differentially to the tissue culture condition remains poorly understood. Results We investigated tissue culture-induced genetic and epigenetic alterations in a set of rice genotypes including two pure-lines (different subspecies), a pair of reciprocal F1 hybrids parented by the two pure-lines, and a pair of reciprocal tetraploids resulted from the hybrids. Using two molecular markers, amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP), both genetic and DNA methylation alterations were detected in calli and regenerants from all six genotypes, but genetic alteration is more prominent than epigenetic alteration. While significant genotypic difference was observed in frequencies of both types of alterations, only genetic alteration showed distinctive features among the three types of genomes, with one hybrid (N/9) being exceptionally labile. Surprisingly, difference in genetic alteration frequencies between the pair of reciprocal F1 hybrids is much greater than that between the two pure-line subspecies. Difference also exists in the pair of reciprocal tetraploids, but is to a less extent than that between the hybrids. The steady-state transcript abundance of genes involved in DNA repair and DNA methylation was significantly altered in both calli and regenerants, and some of which were correlated with the genetic and/or epigenetic alterations. Conclusions Our results, based on molecular marker analysis of ca. 1,000 genomic loci, document that genetic alteration is the major cause of

  4. Tissue culture-induced genetic and epigenetic alterations in rice pure-lines, F1 hybrids and polyploids.

    PubMed

    Wang, Xiaoran; Wu, Rui; Lin, Xiuyun; Bai, Yan; Song, Congdi; Yu, Xiaoming; Xu, Chunming; Zhao, Na; Dong, Yuzhu; Liu, Bao

    2013-05-05

    Genetic and epigenetic alterations can be invoked by plant tissue culture, which may result in heritable changes in phenotypes, a phenomenon collectively termed somaclonal variation. Although extensive studies have been conducted on the molecular nature and spectrum of tissue culture-induced genomic alterations, the issue of whether and to what extent distinct plant genotypes, e.g., pure-lines, hybrids and polyploids, may respond differentially to the tissue culture condition remains poorly understood. We investigated tissue culture-induced genetic and epigenetic alterations in a set of rice genotypes including two pure-lines (different subspecies), a pair of reciprocal F1 hybrids parented by the two pure-lines, and a pair of reciprocal tetraploids resulted from the hybrids. Using two molecular markers, amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP), both genetic and DNA methylation alterations were detected in calli and regenerants from all six genotypes, but genetic alteration is more prominent than epigenetic alteration. While significant genotypic difference was observed in frequencies of both types of alterations, only genetic alteration showed distinctive features among the three types of genomes, with one hybrid (N/9) being exceptionally labile. Surprisingly, difference in genetic alteration frequencies between the pair of reciprocal F1 hybrids is much greater than that between the two pure-line subspecies. Difference also exists in the pair of reciprocal tetraploids, but is to a less extent than that between the hybrids. The steady-state transcript abundance of genes involved in DNA repair and DNA methylation was significantly altered in both calli and regenerants, and some of which were correlated with the genetic and/or epigenetic alterations. Our results, based on molecular marker analysis of ca. 1,000 genomic loci, document that genetic alteration is the major cause of somaclonal variation in rice

  5. Interspecies Extrapolation

    EPA Science Inventory

    Interspecies extrapolation encompasses two related but distinct topic areas that are germane to quantitative extrapolation and hence computational toxicology-dose scaling and parameter scaling. Dose scaling is the process of converting a dose determined in an experimental animal ...

  6. USE OF INTERSPECIES CORRELATION ESTIMATIONS TO PREDICT HC5'S BASED ON QSAR

    EPA Science Inventory

    Dyer, S.D., S. Belanger, J. Chaney, D. Versteeg and F. Mayer. In press. Use of Interspecies Correlation Estimations to predict HC5's Based on QSARs (Abstract). To be presented at the SETAC Europe 14th Annual Meeting: Environmental Science Solution: A Pan-European Perspective, 18-...

  7. Interspecies chimeras.

    PubMed

    Suchy, Fabian; Nakauchi, Hiromitsu

    2018-05-30

    By probing early embryogenesis and regeneration, interspecies chimeras provide a unique platform for discovery and clinical use. Although efficient generation of human:animal chimeric embryos remains elusive, recent advancements attempt to overcome incompatibilities in xenogeneic development and transplantation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. On the persistence of reproductive barriers in Eucalyptus: the bridging of mechanical barriers to zygote formation by F1 hybrids is counteracted by intrinsic post-zygotic incompatibilities.

    PubMed

    Larcombe, Matthew J; Costa E Silva, João; Tilyard, Paul; Gore, Peter; Potts, Brad M

    2016-09-01

    Many previous studies conclude that pre-zygotic barriers such as mechanical isolation account for most reproductive isolation between pairs of taxa. However, the inheritance and persistence of barriers such as these after the first generation of hybridization is rarely quantified, even though it is a vital consideration in understanding gene flow potential. There is an asymmetrical pre-zygotic mechanical barrier to hybridization between Eucalyptus nitens and Eucalyptus globulus, which completely prevents small-flowered E. nitens pollen from mating with large E. globulus flowers, while the reverse cross is possible. We aimed to determine the relative importance of pre- and post-zygotic barriers in preventing gene flow following secondary contact between E. nitens and E. globulus, including the inheritance of barriers in advanced-generation hybrids. Experimental crossing was used to produce outcrossed E. nitens, E. globulus and their F1, F2, BCg and BCn hybrids. The strength and inheritance of a suite of pre- and post-zygotic barriers were assessed, including 20-year survival, growth and reproductive capacity. The mechanical barrier to hybridization was lost or greatly reduced in the F1 hybrid. In contrast, intrinsic post-zygotic barriers were strong and persistent. Line-cross analysis indicated that the outbreeding depression in the hybrids was best explained by epistatic loss. The removal of strong mechanical barriers between E. nitens and E. globulus allows F1 hybrids to act as a bridge for bi-directional gene flow between these species. However, strong and persistent post-zygotic barriers exist, meaning that wherever F1 hybridization does occur, intrinsic post-zygotic barriers will be responsible for most reproductive isolation in this system. This potential transient nature of mechanical barriers to zygote formation due to additive inheritance in hybrids appears under-appreciated, and highlights the often important role that intrinsic post-mating barriers play

  9. Genome-scale transcriptional study of hybrid effects and regulatory divergence in an F1 hybrid Ruellia (Wild Petunias: Acanthaceae) and its parents.

    PubMed

    Zhuang, Yongbin; Tripp, Erin A

    2017-01-17

    New combinations of divergent genomes can give rise to novel genetic functions in resulting hybrid progeny. Such functions may yield opportunities for ecological divergence, contributing ultimately to reproductive isolation and evolutionary longevity of nascent hybrid lineages. In plants, the degree to which transgressive genotypes contribute to floral novelty remains a question of key interest. Here, we generated an F 1 hybrid plant between the red-flowered Ruellia elegans and yellow flowered R. speciosa. RNA-seq technology was used to explore differential gene expression between the hybrid and its two parents, with emphasis on genetic elements involved in the production of floral anthocyanin pigments. The hybrid was purple flowered and produced novel floral delphinidin pigments not manufactured by either parent. We found that nearly a fifth of all 86,475 unigenes expressed were unique to the hybrid. The majority of hybrid unigenes (80.97%) showed a pattern of complete dominance to one parent or the other although this ratio was uneven, suggesting asymmetrical influence of parental genomes on the progeny transcriptome. However, 8.87% of all transcripts within the hybrid were expressed at significantly higher or lower mean levels than observed for either parent. A total of 28 unigenes coding putatively for eight core enzymes in the anthocyanin pathway were recovered, along with three candidate MYBs involved in anthocyanin regulation. Our results suggest that models of gene evolution that explain phenotypic novelty and hybrid establishment in plants may need to include transgressive effects. Additionally, our results lend insight into the potential for floral novelty that derives from unions of divergent genomes. These findings serve as a starting point to further investigate molecular mechanisms involved in flower color transitions in Ruellia.

  10. Observation of interspecies ion separation in inertial-confinement-fusion implosions

    DOE PAGES

    Hsu, Scott C.; Joshi, Tirtha Raj; Hakel, Peter; ...

    2016-10-24

    Here we report direct experimental evidence of interspecies ion separation in direct-drive, inertial-confinement-fusion experiments on the OMEGA laser facility. These experiments, which used plastic capsules with D 2/Ar gas fill (1% Ar by atom), were designed specifically to reveal interspecies ion separation by exploiting the predicted, strong ion thermo-diffusion between ion species of large mass and charge difference. Via detailed analyses of imaging x-ray-spectroscopy data, we extract Ar-atom-fraction radial profiles at different times, and observe both enhancement and depletion compared to the initial 1%-Ar gas fill. The experimental results are interpreted with radiation-hydrodynamic simulations that include recently implemented, first-principles modelsmore » of interspecies ion diffusion. Finally, the experimentally inferred Ar-atom-fraction profiles agree reasonably, but not exactly, with calculated profiles associated with the incoming and rebounding first shock.« less

  11. The self-compatibility mechanism in Brassica napus L. is applicable to F1 hybrid breeding.

    PubMed

    Tochigi, Takahiro; Udagawa, Hisashi; Li, Feng; Kitashiba, Hiroyasu; Nishio, Takeshi

    2011-08-01

    Brassica napus, an allopolyploid species having the A genome of B. rapa and the C genome of B. oleracea, is self-compatible, although both B. rapa and B. oleracea are self-incompatible. We have previously reported that SP11/SCR alleles are not expressed in anthers, while SRK alleles are functional in the stigma in B. napus cv. 'Westar', which has BnS-1 similar to B. rapa S-47 and BnS-6 similar to B. oleracea S-15. This genotype is the most frequent S genotype in B. napus, and we hypothesized that the loss of the function of SP11 is the primary cause of the self-compatibility of 'Westar'. To verify this hypothesis, we transformed 'Westar' plants with the SP11 allele of B. rapa S-47. All the transgenic plants and their progeny were completely self-incompatible, demonstrating self-compatibility to be due to the S haplotype having the non-functional SP11 allele in the A genome, which suppresses a functional recessive SP11 allele in the C genome. An artificially synthesized B. napus line having two recessive SP11 alleles was developed by interspecific hybridization between B. rapa and B. oleracea. This line was self-incompatible, but F(1) hybrids between this line and 'Westar' were self-compatible. These results suggest that the self-compatibility mechanism of 'Westar' is applicable to F(1) seed production in B. napus.

  12. 'Caro-Tex 312’ – An F1 Hybrid, High Yielding, Multiple Disease Resistant, Orange Habanero Pepper Cultivar

    USDA-ARS?s Scientific Manuscript database

    Texas A&M University and the USDA-ARS U.S. Vegetable Laboratory in Charleston, SC, have developed a new, F1 hybrid Habanero pepper cultivar. ‘Caro-Tex 312’ produces a large, orange-fruited Habanero pepper with typical shape and high pungency. It also possesses unique yield, early maturity and dise...

  13. Interspecies chemical communication in bacterial development.

    PubMed

    Straight, Paul D; Kolter, Roberto

    2009-01-01

    Our view of bacteria, from the earliest observations through the heyday of antibiotic discovery, has shifted dramatically. We recognize communities of bacteria as integral and functionally important components of diverse habitats, ranging from soil collectives to the human microbiome. To function as productive communities, bacteria coordinate metabolic functions, often requiring shifts in growth and development. The hallmark of cellular development, which we characterize as physiological change in response to environmental stimuli, is a defining feature of many bacterial interspecies interactions. Bacterial communities rely on chemical exchanges to provide the cues for developmental change. Traditional methods in microbiology focus on isolation and characterization of bacteria in monoculture, separating the organisms from the surroundings in which interspecies chemical communication has relevance. Developing multispecies experimental systems that incorporate knowledge of bacterial physiology and metabolism with insights from biodiversity and metagenomics shows great promise for understanding interspecies chemical communication in the microbial world.

  14. Non-introgressive genome chimerisation by malsegregation in autodiploidised allotetraploids during meiosis of Saccharomyces kudriavzevii x Saccharomyces uvarum hybrids.

    PubMed

    Karanyicz, Edina; Antunovics, Zsuzsa; Kallai, Z; Sipiczki, M

    2017-06-01

    Saccharomyces strains with chimerical genomes consisting of mosaics of the genomes of different species ("natural hybrids") occur quite frequently among industrial and wine strains. The most widely endorsed hypothesis is that the mosaics are introgressions acquired via hybridisation and repeated backcrosses of the hybrids with one of the parental species. However, the interspecies hybrids are sterile, unable to mate with their parents. Here, we show by analysing synthetic Saccharomyces kudriavzevii x Saccharomyces uvarum hybrids that mosaic (chimeric) genomes can arise without introgressive backcrosses. These species are biologically separated by a double sterility barrier (sterility of allodiploids and F1 sterility of allotetraploids). F1 sterility is due to the diploidisation of the tetraploid meiosis resulting in MAT a /MAT α heterozygosity which suppresses mating in the spores. This barrier can occasionally be broken down by malsegregation of autosyndetically paired chromosomes carrying the MAT loci (loss of MAT heterozygosity). Subsequent malsegregation of additional autosyndetically paired chromosomes and occasional allosyndetic interactions chimerise the hybrid genome. Chromosomes are preferentially lost from the S. kudriavzevii subgenome. The uniparental transmission of the mitochondrial DNA to the hybrids indicates that nucleo-mitochondrial interactions might affect the direction of the genomic changes. We propose the name GARMe (Genome AutoReduction in Meiosis) for this process of genome reduction and chimerisation which involves no introgressive backcrossings. It opens a way to transfer genetic information between species and thus to get one step ahead after hybridisation in the production of yeast strains with beneficial combinations of properties of different species.

  15. Introgressive hybridization and latitudinal admixture clines in North Atlantic eels

    PubMed Central

    2014-01-01

    Background Hybridization, the interbreeding of diagnosably divergent species, is a major focus in evolutionary studies. Eels, both from North America and Europe migrate through the Atlantic to mate in a vast, overlapping area in the Sargasso Sea. Due to the lack of direct observation, it is unknown how these species remain reproductively isolated. The detection of inter-species hybrids in Iceland suggests on-going gene flow, but few studies to date have addressed the influence of introgression on genetic differentiation in North Atlantic eels. Results Here, we show that while mitochondrial lineages remain completely distinct on both sides of the Atlantic, limited hybridization is detectable with nuclear DNA markers. The nuclear hybridization signal peaks in the northern areas and decreases towards the southern range limits on both continents according to Bayesian assignment analyses. By simulating increasing proportions of both F1 hybrids and admixed individuals from the southern to the northern-most locations, we were able to generate highly significant isolation-by-distance patterns in both cases, reminiscent of previously published data for the European eel. Finally, fitting an isolation-with-migration model to our data supports the hypothesis of recent asymmetric introgression and refutes the alternative hypothesis of ancient polymorphism. Conclusions Fluctuating degrees of introgressive hybridization between Atlantic eel species are sufficient to explain temporally varying correlations of geographic and genetic distances reported for populations of the European eel. PMID:24674242

  16. Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans.

    PubMed

    Wei, Yuan; Qiu, Wei; Zhou, Xue-Dong; Zheng, Xin; Zhang, Ke-Ke; Wang, Shi-Da; Li, Yu-Qing; Cheng, Lei; Li, Ji-Yao; Xu, Xin; Li, Ming-Yun

    2016-12-16

    D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial cell wall synthesis. Alanine racemase (Alr) is a unique enzyme that interconverts L-alanine and D-alanine in most bacteria, making this enzyme a potential target for antimicrobial drug development. Streptococcus mutans is a major causative factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Alr in S. mutans. We constructed alr mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that alr deletion was lethal to S. mutans. A minimal supplement of D-Ala (150 μg·mL -1 ) was required for the optimal growth of the alr mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the alr mutant strain. We also determined the compromised competitiveness of the alr mutant strain relative to the wild-type S. mutans against other oral streptococci (S. sanguinis or S. gordonii), demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of alr to the growth and competitiveness of S. mutans, Alr may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries.

  17. Interspecies protein substitution to investigate the role of the lyssavirus glycoprotein.

    PubMed

    Marston, Denise A; McElhinney, Lorraine M; Banyard, Ashley C; Horton, Daniel L; Núñez, Alejandro; Koser, Martin L; Schnell, Matthias J; Fooks, Anthony R

    2013-02-01

    European bat lyssaviruses type 1 (EBLV-1) and type 2 (EBLV-2) circulate within bat populations throughout Europe and are capable of causing disease indistinguishable from that caused by classical rabies virus (RABV). However, the determinants of viral fitness and pathogenicity are poorly understood. Full-length genome clones based on the highly attenuated, non-neuroinvasive, RABV vaccine strain (SAD-B19) were constructed with the glycoprotein (G) of either SAD-B19 (SN), of EBLV-1 (SN-1) or EBLV-2 (SN-2). In vitro characterization of SN-1 and SN-2 in comparison to wild-type EBLVs demonstrated that the substitution of G affected the final virus titre and antigenicity. In vivo, following peripheral infection with a high viral dose (10(4) f.f.u.), animals infected with SN-1 had reduced survivorship relative to infection with SN, resulting in survivorship similar to animals infected with EBLV-1. The histopathological changes and antigen distribution observed for SN-1 were more representative of those observed with SN than with EBLV-1. EBLV-2 was unable to achieve a titre equivalent to that of the other viruses. Therefore, a reduced-dose experiment (10(3) f.f.u.) was undertaken in vivo to compare EBLV-2 and SN-2, which resulted in 100 % survivorship for all recombinant viruses (SN, SN-1 and SN-2) while clinical disease developed in mice infected with the EBLVs. These data indicate that interspecies replacement of G has an effect on virus titre in vitro, probably as a result of suboptimal G-matrix protein interactions, and influences the survival outcome following a peripheral challenge with a high virus titre in mice.

  18. Interallelic and Intergenic Incompatibilities of the Prdm9 (Hst1) Gene in Mouse Hybrid Sterility

    PubMed Central

    Flachs, Petr; Mihola, Ondřej; Šimeček, Petr; Gregorová, Soňa; Schimenti, John C.; Matsui, Yasuhisa; Baudat, Frédéric; de Massy, Bernard; Piálek, Jaroslav; Forejt, Jiří; Trachtulec, Zdenek

    2012-01-01

    The Dobzhansky-Muller model of incompatibilities explains reproductive isolation between species by incorrect epistatic interactions. Although the mechanisms of speciation are of great interest, no incompatibility has been characterized at the gene level in mammals. The Hybrid sterility 1 gene (Hst1) participates in the arrest of meiosis in F1 males of certain strains from two Mus musculus subspecies, e.g., PWD from M. m. musculus and C57BL/6J (henceforth B6) from M. m. domesticus. Hst1 has been identified as a meiotic PR-domain gene (Prdm9) encoding histone 3 methyltransferase in the male offspring of PWD females and B6 males, (PWD×B6)F1. To characterize the incompatibilities underlying hybrid sterility, we phenotyped reproductive and meiotic markers in males with altered copy numbers of Prdm9. A partial rescue of fertility was observed upon removal of the B6 allele of Prdm9 from the azoospermic (PWD×B6)F1 hybrids, whereas removing one of the two Prdm9 copies in PWD or B6 background had no effect on male reproduction. Incompatibility(ies) not involving Prdm9B6 also acts in the (PWD×B6)F1 hybrids, since the correction of hybrid sterility by Prdm9B6 deletion was not complete. Additions and subtractions of Prdm9 copies, as well as allelic replacements, improved meiotic progression and fecundity also in the progeny-producing reciprocal (B6×PWD)F1 males. Moreover, an increased dosage of Prdm9 and reciprocal cross enhanced fertility of other sperm-carrying male hybrids, (PWD×B6-C3H.Prdm9)F1, harboring another Prdm9 allele of M. m. domesticus origin. The levels of Prdm9 mRNA isoforms were similar in the prepubertal testes of all types of F1 hybrids of PWD with B6 and B6-C3H.Prdm9 despite their different prospective fertility, but decreased to 53% after removal of Prdm9B6. Therefore, the Prdm9B6 allele probably takes part in posttranscriptional dominant-negative hybrid interaction(s) absent in the parental strains. PMID:23133405

  19. Interallelic and intergenic incompatibilities of the Prdm9 (Hst1) gene in mouse hybrid sterility.

    PubMed

    Flachs, Petr; Mihola, Ondřej; Simeček, Petr; Gregorová, Soňa; Schimenti, John C; Matsui, Yasuhisa; Baudat, Frédéric; de Massy, Bernard; Piálek, Jaroslav; Forejt, Jiří; Trachtulec, Zdenek

    2012-01-01

    The Dobzhansky-Muller model of incompatibilities explains reproductive isolation between species by incorrect epistatic interactions. Although the mechanisms of speciation are of great interest, no incompatibility has been characterized at the gene level in mammals. The Hybrid sterility 1 gene (Hst1) participates in the arrest of meiosis in F(1) males of certain strains from two Mus musculus subspecies, e.g., PWD from M. m. musculus and C57BL/6J (henceforth B6) from M. m. domesticus. Hst1 has been identified as a meiotic PR-domain gene (Prdm9) encoding histone 3 methyltransferase in the male offspring of PWD females and B6 males, (PWD×B6)F(1). To characterize the incompatibilities underlying hybrid sterility, we phenotyped reproductive and meiotic markers in males with altered copy numbers of Prdm9. A partial rescue of fertility was observed upon removal of the B6 allele of Prdm9 from the azoospermic (PWD×B6)F(1) hybrids, whereas removing one of the two Prdm9 copies in PWD or B6 background had no effect on male reproduction. Incompatibility(ies) not involving Prdm9(B6) also acts in the (PWD×B6)F(1) hybrids, since the correction of hybrid sterility by Prdm9(B6) deletion was not complete. Additions and subtractions of Prdm9 copies, as well as allelic replacements, improved meiotic progression and fecundity also in the progeny-producing reciprocal (B6×PWD)F(1) males. Moreover, an increased dosage of Prdm9 and reciprocal cross enhanced fertility of other sperm-carrying male hybrids, (PWD×B6-C3H.Prdm9)F(1), harboring another Prdm9 allele of M. m. domesticus origin. The levels of Prdm9 mRNA isoforms were similar in the prepubertal testes of all types of F(1) hybrids of PWD with B6 and B6-C3H.Prdm9 despite their different prospective fertility, but decreased to 53% after removal of Prdm9(B6). Therefore, the Prdm9(B6) allele probably takes part in posttranscriptional dominant-negative hybrid interaction(s) absent in the parental strains.

  20. Production of F1 interspecies hybrid offspring with cryopreserved sperm from a live-bearing fish, the swordtail Xiphophorus helleri.

    PubMed

    Yang, Huiping; Hazlewood, Leona; Heater, Sheila J; Guerrero, Paula A; Walter, Ronald B; Tiersch, Terrence R

    2007-03-01

    Despite study of sperm cryopreservation in more than 200 fish species, production of broods from cryopreserved sperm in live-bearing fish has not been demonstrated. This has not been due to a lack of effort, but instead is a result of the unique morphology, biology, and biochemistry of reproduction in viviparous fishes. For example, sperm of Xiphophorus helleri have a cylindrical nucleus, can swim for days after being activated, have glycolytic capabilities, and can reside in the female reproduction tract for months before fertilization. These traits are not found in fishes with external fertilization. The long-standing research use of the genus Xiphophorus has led to development of over 60 pedigreed lines among the 26 species maintained around the world. These species and lines serve as contemporary models in medical research, although they must be maintained as live populations. Previous attempts at establishing sperm cryopreservation protocols for Xiphophorus have not produced live young. To address this we have been studying the parameters surrounding cryobiology of Xiphophorus sperm and applying this information to an improved understanding of internal fertilization and reproduction. Here we report the first successful fertilization and offspring production by cryopreserved sperm in any live-bearing fish. This claim is supported by our use of artificial insemination between two species that yield distinct hybrid offspring to verify paternity via cryopreserved sperm. We provide a practical approach for preservation of valuable genetic resources from live-bearing fish species, a group that is rapidly being lost due to destruction of native habitats.

  1. Cellular origin of fibronectin in interspecies hybrid kidneys

    PubMed Central

    1984-01-01

    The cellular origin of fibronectin in the kidney was studied in three experimental models. Immunohistochemical techniques that use cross- reacting or species-specific antibodies against mouse or chicken fibronectin were employed. In the first model studied, initially avascular mouse kidneys cultured on avian chorioallantoic membranes differentiate into epithelial kidney tubules and become vascularized by chorioallantoic vessels. Subsequently, hybrid glomeruli composed of mouse podocytes and avian endothelial-mesangial cells form. In immunohistochemical studies, cross-reacting antibodies to fibronectin stained vascular walls, tubular basement membranes, interstitium, and glomeruli of mouse kidney grafts. The species-specific antibodies reacting only with mouse fibronectin stained interstitial areas and tubular basement membranes, but showed no reaction with hybrid glomeruli and avian vascular walls. In contrast, species-specific antibodies against chicken fibronectin stained both the interstitial areas and the vascular walls as well as the endothelial-mesangial areas of the hybrid glomeruli, but did not stain the mouse-derived epithelial structures of the kidneys. In the second model, embryonic kidneys cultured under avascular conditions in vitro develop glomerular tufts, which are devoid of endothelial cells. These explants showed fluorescence staining for fibronectin only in tubular basement membranes and in interstitium. The avascular, purely epithelial glomerular bodies remained unstained. Finally, in outgrowths of separated embryonic glomeruli, the cross-reacting fibronectin antibodies revealed two populations of cells: one devoid of fibronectin and another expressing fibronectin in strong fibrillar and granular patterns. These results favor the idea that the main endogenous cellular sources for fibronectin in the embryonic kidney are the interstitial and vascular cells. All experiments presented here suggest that fibronectin is not synthesized by glomerular

  2. [Study of biological value of beef produced by interspecies hybrids of domestic cattle and wild yaks].

    PubMed

    Bagirov, V A; Chernukha, I M; Lisitsin, A V; Zinovieva, N A

    2014-01-01

    The comparative study of the chemical composition and biological values of beef produced by hybrids of Angus cattle with wild yaks (hybrid beef) and pure-bred Angus cattle (traditional beef) has been carried out. Longissimus muscle samples were used for analysis. It was observed, that the hybrid beef samples had the practically equal protein content comparing to traditional beef (21.1 vs. 21.6 per cent) but were characterized by the lower fat content (1.2 vs. 2.5 per cent). The higher biological value of hybrid beef comparing to traditional beef has been shown. The value of protein-quality index, calculated as the ratio of tryptophan amino acid to oxyprolin and characterizing the ratio of high biological value proteins to low biological value proteins was 8.1 vs. 5.7. The values of amino acid indexes [ratio of essential amino acids (EAA) to non-essential amino acids (NAA) and ratio of EAA to the total amount of amino acids (TAA)] were EAA/NAA = 0.77 vs. 0.65 and EAA/TAA = 0.43 vs. 0.39. The protein of hybrid beef was characterized by the higher content of a number of the essential amino acids: by a factor of 1, 77 for threonin, 1.23--for valin, 1.09--for lysin, 1.17--for leucine and 1.19--for tryptophan. The amount of the essential amino acids in 1 gram of protein of the hybrid beef was 434.7 mg against 393.1 mg for traditional beef It has been shown, that the protein of the hybrid beef comparing to traditional beef is characterized by the higher values of the amino acid scores calculated for EAA.

  3. Assessing Uncertainty of Interspecies Correlation Estimation Models for Aromatic Compounds

    EPA Science Inventory

    We developed Interspecies Correlation Estimation (ICE) models for aromatic compounds containing 1 to 4 benzene rings to assess uncertainty in toxicity extrapolation in two data compilation approaches. ICE models are mathematical relationships between surrogate and predicted test ...

  4. Interspecies interactions are an integral determinant of microbial community dynamics

    PubMed Central

    Aziz, Fatma A. A.; Suzuki, Kenshi; Ohtaki, Akihiro; Sagegami, Keita; Hirai, Hidetaka; Seno, Jun; Mizuno, Naoko; Inuzuka, Yuma; Saito, Yasuhisa; Tashiro, Yosuke; Hiraishi, Akira; Futamata, Hiroyuki

    2015-01-01

    This study investigated the factors that determine the dynamics of bacterial communities in a complex system using multidisciplinary methods. Since natural and engineered microbial ecosystems are too complex to study, six types of synthetic microbial ecosystems (SMEs) were constructed under chemostat conditions with phenol as the sole carbon and energy source. Two to four phenol-degrading, phylogenetically and physiologically different bacterial strains were used in each SME. Phylogeny was based on the nucleotide sequence of 16S rRNA genes, while physiologic traits were based on kinetic and growth parameters on phenol. Two indices, J parameter and “interspecies interaction,” were compared to predict which strain would become dominant in an SME. The J parameter was calculated from kinetic and growth parameters. On the other hand, “interspecies interaction,” a new index proposed in this study, was evaluated by measuring the specific growth activity, which was determined on the basis of relative growth of a strain with or without the supernatant prepared from other bacterial cultures. Population densities of strains used in SMEs were enumerated by real-time quantitative PCR (qPCR) targeting the gene encoding the large subunit of phenol hydroxylase and were compared to predictions made from J parameter and interspecies interaction calculations. In 4 of 6 SEMs tested the final dominant strain shown by real-time qPCR analyses coincided with the strain predicted by both the J parameter and the interspecies interaction. However, in SMEII-2 and SMEII-3 the final dominant Variovorax strains coincided with prediction of the interspecies interaction but not the J parameter. These results demonstrate that the effects of interspecies interactions within microbial communities contribute to determining the dynamics of the microbial ecosystem. PMID:26539177

  5. Restriction endonuclease analysis of chloroplast DNA in interspecies somatic Hybrids of Petunia.

    PubMed

    Kumar, A; Cocking, E C; Bovenberg, W A; Kool, A J

    1982-12-01

    Restriction endonuclease cleavage pattern analysis of chloroplast DNA (cpDNA) of three different interspecific somatic hybrid plants revealed that the cytoplasms of the hybrids contained only cpDNA of P. parodii. The somatic hybrid plants analysed were those between P. parodii (wild type) + P. hybrida (wild type); P. parodii (wild type)+P. inflata (cytoplasmic albino mutant); P. parodii (wild type) + P. parviflora (nuclear albino mutant). The presence of only P. parodii chloroplasts in the somatic hybrid of P. parodii + P. inflata is possibly due to the stringent selection used for somatic hybrid production. However, in the case of the two other somatic hybrids P. parodii + P. hybrida and P. parodii + P. parviflora it was not possible to determine whether the presence of only P. parodii chloroplasts in these somatic hybrid plants was due to the nature of the selection schemes used or simply occurred by chance. The relevance of such somatic hybrid material for the study of genomic-cytoplasmic interaction is discussed, as well as the use of restriction endonuclease fragment patterns for the analysis of taxonomic and evolutionary inter-relationships in the genus Petunia.

  6. [Inheritance of bc1 gene in intersubspecific hybrids of rice (Oryza sativa L.)].

    PubMed

    Lü, Chuan-Gen; Zong, Shou-Yu; Zhao, Ling; Qi, Qing-Ming; Zou, Jiang-Shi; Ikehashi, Hiroshi

    2004-10-01

    Distorted segregation of the brittle culm-1 gene (bc1) on rice chromosome 3 was found with greatly increased or decreased frequency of bc1 bc1 genotype in inter-subspecific hybrids, although the gene normally transmitted to its offspring following the Mendelian Law in intra-subspecific hybrids. In a combination of Kamairazu//Ketan Nangka/Kamairazu,an increased frequency of bc1 bc1 in F1, normal segregation in F2, and increased and decreased frequency in a few F3 and F4 lines were observed. In a cross of IR36/Kamairazu, decreased frequency in F2, both normal and decreased segregations in F3 and F4, and a few lines of increased ratio in F4 were found. In F2 of Ketan Nangka/IR36//Kamairazu, increased and decreased and normal segregations were all observed. There was no significant correlation between the frequency of bc1 bc1 and pollen fertility. It implied that distorted segregation of bc1 was caused by selective fertilization of male gametes, which were governed by gametophyte genes of ga2, ga3 and ga14 on chromosome 3.

  7. Comparison between hybrid feedforward-feedback, feedforward, and feedback structures for active noise control of fMRI noise.

    PubMed

    Reddy, Rajiv M; Panahi, Issa M S

    2008-01-01

    The performance of FIR feedforward, IIR feedforward, FIR feedback, hybrid FIR feedforward--FIR feedback, and hybrid IIR feedforward - FIR feedback structures for active noise control (ANC) are compared for an fMRI noise application. The filtered-input normalized least squares (FxNLMS) algorithm is used to update the coefficients of the adaptive filters in all these structures. Realistic primary and secondary paths of an fMRI bore are used by estimating them on a half cylindrical acrylic bore of 0.76 m (D)x1.52 m (L). Detailed results of the performance of the ANC system are presented in the paper for each of these structures. We find that the IIR feedforward structure produces most of the performance improvement in the hybrid IIR feedforward - FIR feedback structure and adding the feedback structure becomes almost redundant in the case of fMRI noise.

  8. Hybrid radioguided occult lesion localization (hybrid ROLL) of (18)F-FDG-avid lesions using the hybrid tracer indocyanine green-(99m)Tc-nanocolloid.

    PubMed

    KleinJan, G H; Brouwer, O R; Mathéron, H M; Rietbergen, D D D; Valdés Olmos, R A; Wouters, M W; van den Berg, N S; van Leeuwen, F W B

    2016-01-01

    To assess if combined fluorescence- and radio-guided occult lesion localization (hybrid ROLL) is feasible in patients scheduled for surgical resection of non-palpable (18)F-FDG-avid lesions on PET/CT. Four patients with (18)F-FDG-avid lesions on follow-up PET/CT that were not palpable during physical examination but were suspected to harbor metastasis were enrolled. Guided by ultrasound, the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was injected centrally in the target lesion. SPECT/CT imaging was used to confirm tracer deposition. Intraoperatively, lesions were localized using a hand-held gamma ray detection probe, a portable gamma camera, and a fluorescence camera. After excision, the gamma camera was used to check the wound bed for residual activity. A total of six (18)F-FDG-avid lymph nodes were identified and scheduled for hybrid ROLL. Comparison of the PET/CT images with the acquired SPECT/CT after hybrid tracer injection confirmed accurate tracer deposition. No side effects were observed. Combined radio- and fluorescence-guidance enabled localization and excision of the target lesion in all patients. Five of the six excised lesions proved tumor-positive at histopathology. The hybrid ROLL approach appears to be feasible and can facilitate the intraoperative localization and excision of non-palpable lesions suspected to harbor tumor metastases. In addition to the initial radioguided detection, the fluorescence component of the hybrid tracer enables high-resolution intraoperative visualization of the target lesion. The procedure needs further evaluation in a larger cohort and wider range of malignancies to substantiate these preliminary findings. Copyright © 2016 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  9. Lessons from Interspecies Mammalian Chimeras.

    PubMed

    Suchy, Fabian; Nakauchi, Hiromitsu

    2017-10-06

    As chimeras transform from beasts of Greek mythology into tools of contemporary bioscience, secrets of developmental biology and evolutionary divergence are being revealed. Recent advances in stem cell biology and interspecies chimerism have generated new models with extensive basic and translational applications, including generation of transplantable, patient-specific organs.

  10. Hybridization and adaptive evolution of diverse Saccharomyces species for cellulosic biofuel production

    DOE PAGES

    Peris, David; Moriarty, Ryan V.; Alexander, William G.; ...

    2017-03-27

    Here, lignocellulosic biomass is a common resource across the globe, and its fermentation offers a promising option for generating renewable liquid transportation fuels. The deconstruction of lignocellulosic biomass releases sugars that can be fermented by microbes, but these processes also produce fermentation inhibitors, such as aromatic acids and aldehydes. Several research projects have investigated lignocellulosic biomass fermentation by the baker’s yeast Saccharomyces cerevisiae. Most projects have taken synthetic biological approaches or have explored naturally occurring diversity in S. cerevisiae to enhance stress tolerance, xylose consumption, or ethanol production. Despite these efforts, improved strains with new properties are needed. In othermore » industrial processes, such as wine and beer fermentation, interspecies hybrids have combined important traits from multiple species, suggesting that interspecies hybridization may also offer potential for biofuel research.« less

  11. Hybridization and adaptive evolution of diverse Saccharomyces species for cellulosic biofuel production

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

    Peris, David; Moriarty, Ryan V.; Alexander, William G.

    Here, lignocellulosic biomass is a common resource across the globe, and its fermentation offers a promising option for generating renewable liquid transportation fuels. The deconstruction of lignocellulosic biomass releases sugars that can be fermented by microbes, but these processes also produce fermentation inhibitors, such as aromatic acids and aldehydes. Several research projects have investigated lignocellulosic biomass fermentation by the baker’s yeast Saccharomyces cerevisiae. Most projects have taken synthetic biological approaches or have explored naturally occurring diversity in S. cerevisiae to enhance stress tolerance, xylose consumption, or ethanol production. Despite these efforts, improved strains with new properties are needed. In othermore » industrial processes, such as wine and beer fermentation, interspecies hybrids have combined important traits from multiple species, suggesting that interspecies hybridization may also offer potential for biofuel research.« less

  12. Formation of diploid and triploid hybrid groupers (hybridization of Epinephelus coioides ♀ × Epinephelus lanceolatus ♂) and their 5S gene analysis.

    PubMed

    Huang, Wen; Qin, Qinbo; Yang, Huirong; Li, Shuisheng; Hu, Chaoqun; Wang, Yude; Zhang, Yong; Liu, Shaojun; Lin, Haoran

    2016-10-07

    Interspecies hybridization is widely used to achieve heterosis or hybrid vigor, which has been observed and harnessed by breeders for centuries. Natural allopolyploid hybrids generally exhibit more superior heterosis than both the diploid progenies and their parental species. However, polyploid formation processes have been long ignored, the genetic basis of heterosis in polyploids remains elusive. In the present study, triploid hybrids had been demonstrated to contain two sets of chromosomes from mother species and one set from father species. Cellular polyploidization process in the embryos had been traced. The triploid hybrids might be formed by failure formation of the second polarized genome during the second meiosis stage. Four spindle centers were observed in anaphase stage of the first cell division. Three spindle centers were observed in side of cell plate after the first cell division. The 5S rDNA genes of four types of groupers were cloned and analyzed. The diploid and triploid hybrids had been proved to contain the tandem chimera structures which were recombined by maternal and paternal monomer units. The results indicated that genome re-fusion had occurred in the hybrid progenies. To further elucidate the genetic patterns of diploid and triploid hybrids, fluorescence chromosome location had been carried out, maternal 5S gene (M-386) were used as the probe. The triploid hybrids contained fewer fluorescence loci numbers than the maternal species. The results indicated that participation of paternal 5S gene in the triploid hybrid genome had degraded the match rates of M-386 probe. Our study is the first to investigate the cellular formation processes of natural allopolyploids in hybrid fish, the cellular polyploidization process may be caused by failure formation of the second polarized genome during the meiosis, and our results will provide the molecular basis of hybrid vigor in interspecies hybridization.

  13. Fabrication of TEOS/PDMS/F127 hybrid coating materials for conservation of historic stone sculptures

    NASA Astrophysics Data System (ADS)

    Liu, Yurong; Liu, Jia

    2016-08-01

    The present work was aimed to develop a new kind of stone conservation materials (TEOS/PDMS/F127 hybrid coating) by a facile sol-gel method for the protection of decayed sandstones of Chongqing Dazu stone sculptures in China. The hydrophobic property, surface morphology, water vapor permeability, ultraviolet aging resistance and mechanical properties were measured to evaluate the effectiveness of TEOS/PDMS/F127 hybrid coating as a stone conservation material. The results showed that the addition of hydroxyl-terminated polydimethylsiloxane (PDMS-OH) contributed to improve the hydrophobic properties and incorporation of PEO-PPO-PEO (F127) surfactant resulted in the formation of superficial protrusions with micro- and nanoscopic structures and overall alteration of surface morphology and roughness, thus preventing the coating materials from cracking. After treatment with TEOS/PDMS/F127 hybrid coating materials, the ultraviolet aging resistance and mechanical properties of stone were also improved without the obvious effects on the breathability and color of the stone, indicating promising applications of TEOS/PDMS/F127 hybrid coating materials for conservation of historic stone sculptures.

  14. INTERSPECIES DOSIMETRY MODELS FOR PULMONARY PHARMACOLOGY

    EPA Science Inventory

    Interspecies Dosimetry Models for Pulmonary Pharmacology

    Ted B. Martonen, Jeffry D. Schroeter, and John S. Fleming

    Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangl...

  15. Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual Version 3.1

    EPA Science Inventory

    Predictive toxicological models are integral to ecological risk assessment because data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ge...

  16. A Trichosporonales genome tree based on 27 haploid and three evolutionarily conserved 'natural' hybrid genomes.

    PubMed

    Takashima, Masako; Sriswasdi, Sira; Manabe, Ri-Ichiroh; Ohkuma, Moriya; Sugita, Takashi; Iwasaki, Wataru

    2018-01-01

    To construct a backbone tree consisting of basidiomycetous yeasts, draft genome sequences from 25 species of Trichosporonales (Tremellomycetes, Basidiomycota) were generated. In addition to the hybrid genomes of Trichosporon coremiiforme and Trichosporon ovoides that we described previously, we identified an interspecies hybrid genome in Cutaneotrichosporon mucoides (formerly Trichosporon mucoides). This hybrid genome had a gene retention rate of ~55%, and its closest haploid relative was Cutaneotrichosporon dermatis. After constructing the C. mucoides subgenomes, we generated a phylogenetic tree using genome data from the 27 haploid species and the subgenome data from the three hybrid genome species. It was a high-quality tree with 100% bootstrap support for all of the branches. The genome-based tree provided superior resolution compared with previous multi-gene analyses. Although our backbone tree does not include all Trichosporonales genera (e.g. Cryptotrichosporon), it will be valuable for future analyses of genome data. Interest in interspecies hybrid fungal genomes has recently increased because they may provide a basis for new technologies. The three Trichosporonales hybrid genomes described in this study are different from well-characterized hybrid genomes (e.g. those of Saccharomyces pastorianus and Saccharomyces bayanus) because these hybridization events probably occurred in the distant evolutionary past. Hence, they will be useful for studying genome stability following hybridization and speciation events. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Spontaneous polyploidy, gynogenesis and androgenesis in second generation (F2 ) koi Cyprinus carpio × goldfish Carassius auratus hybrids.

    PubMed

    Delomas, T A; Gomelsky, B; Anil, A; Schneider, K J; Warner, J L

    2017-01-01

    The objective of this study was to characterize the genetics of second generation (F 2 ) koi Cyprinus carpio × goldfish Carassius auratus hybrids. Spermatozoa produced by a novel, fertile F 1 male were found to be diploid by flow-cytometric analysis. Backcross (F 1 female × C. carpio male and C. carpio female × F 1 male) juveniles were triploid, confirming that female and male F 1 hybrids both produced diploid gametes. The vast majority of surviving F 2 juveniles was diploid and small proportions were aneuploid (2·1n-2·3n and 3·1n-3·9n), triploid (3n) and tetraploid (4n). Microsatellite genotyping showed that F 2 diploids repeated either the complete maternal or the complete paternal genotype. Fish with the maternal genotype were female and fish with the paternal genotype were male. This demonstrates that F 2 diploids were the result of spontaneous gynogenesis and spontaneous androgenesis. Analysis of microsatellite inheritance and the sex ratio in F 2 crosses showed that spontaneous gynogenesis and androgenesis did not always occur in equal proportions. One cross was found to have an approximate equal number of androgenetic and gynogenetic offspring while in several other crosses spontaneous androgenesis was found to occur more frequently than spontaneous gynogenesis. © 2016 The Fisheries Society of the British Isles.

  18. Cytogenetics off interpopulation Cuphea lanceolata hybrids.

    PubMed

    Ali, M S; Knapp, S J

    1995-12-01

    Cuphea lanceolata Ait. (Lythraceae) is an annual diploid (x = 6) with medium-chain fatty acid rich seed oils. Wild C. lanceolata populations are classified as C. lanceolata f. silenoides or C. lanceolata f. lanceolata on the basis of flower pigment differences. Although these taxa are taxonomically close, their interfertility has not been demonstrated. We describe meiotic phenomena underlying the sterility of hybrids between C. lanceolata f. silenoides (LNS-43) and C. lanceolata f. lanceolata (LNC-78) populations. We assayed metaphase and anaphase I microsporocytes of the parent and hybrid populations. The hybrids were female and male sterile. The mean percentage of stainable pollen was 94.9% for the parents and 1.1% for the hybrids. Chromosomes paired and disjoined normally in the parents (LNS-43 and LNC-78) and abnormally in the hybrids (LNS-43 x LNC-78 and LNC-78 x LNS-43). Univalents, unequal chromosome distributions, and laggards were observed in the hybrids. The mean number of univalents per cell was 0.00 for the parents and 5.95 for the hybrids, the mean number of bivalents per cell was 6.00 for the parents and 1.51 for the hybrids, and the mean number of chiasmata per cell was 9.19 for the parents and 4.04 for the hybrids. The most frequently observed (75%) anaphase I chromosome distribution for the hybrids was 7:5:0 (pole-pole-laggards). The genome affinities of the hybrids were half those of the parents (a mean of 0.5 for the hybrids as opposed to 1.0 for the parents). Although C. lanceolata f. silenoides and C. lanceolata f. lanceolata freely hybridize, their progeny are sterile, and the genetic diversity of LNC-78, and perhaps of C. lanceolata f. lanceolata as a whole, cannot be accessed through hybrids with C. lanceolata f. silenoides or C. viscosissima.

  19. Borders and Comparative Cytoarchitecture of the Perirhinal and Postrhinal Cortices in an F1 Hybrid Mouse

    PubMed Central

    Beaudin, Stephane A.; Singh, Teghpal; Agster, Kara L.

    2013-01-01

    We examined the cytoarchitectonic and chemoarchitectonic organization of the cortical regions associated with the posterior rhinal fissure in the mouse brain, within the framework of what is known about these regions in the rat. Primary observations were in a first-generation hybrid mouse line, B6129PF/J1. The F1 hybrid was chosen because of the many advantages afforded in the study of the molecular and cellular bases of learning and memory. Comparisons with the parent strains, the C57BL6/J and 129P3/J are also reported. Mouse brain tissue was processed for visualization of Nissl material, myelin, acetyl cholinesterase, parvalbumin, and heavy metals. Tissue stained for heavy metals by the Timm’s method was particularly useful in the assignment of borders and in the comparative analyses because the patterns of staining were similar across species and strains. As in the rat, the areas examined were parcellated into 2 regions, the perirhinal and the postrhinal cortices. The perirhinal cortex was divided into areas 35 and 36, and the postrhinal cortex was divided into dorsal (PORd) and ventral (PORv) subregions. In addition to identifying the borders of the perirhinal cortex, we were able to identify a region in the mouse brain that shares signature features with the rat postrhinal cortex. PMID:22368084

  20. Suppression or knockout of SaF/SaM overcomes the Sa-mediated hybrid male sterility in rice.

    PubMed

    Xie, Yongyao; Niu, Baixiao; Long, Yunming; Li, Gousi; Tang, Jintao; Zhang, Yaling; Ren, Ding; Liu, Yao-Guang; Chen, Letian

    2017-09-01

    Hybrids between the indica and japonica subspecies of rice (Oryza sativa) are usually sterile, which hinders utilization of heterosis in the inter-subspecific hybrid breeding. The complex locus Sa comprises two adjacently located genes, SaF and SaM, which interact to cause abortion of pollen grains carrying the japonica allele in japonica-indica hybrids. Here we showed that silencing of SaF or SaM by RNA interference restored male fertility in indica-japonica hybrids with heterozygous Sa. We further used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing to knockout the SaF and SaM alleles, respectively, of an indica rice line to create hybrid-compatible lines. The resultant artificial neutral alleles did not affect pollen viability and other agricultural traits, but did break down the reproductive barrier in the hybrids. We found that some rice lines have natural neutral allele Sa-n, which was compatible with the typical japonica or indica Sa alleles in hybrids. Our results demonstrate that SaF and SaM are required for hybrid male sterility, but are not essential for pollen development. This study provides effective approaches for the generation of hybrid-compatible lines by knocking out the Sa locus or using the natural Sa-n allele to overcome hybrid male sterility in rice breeding. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. © 2017 Institute of Botany, Chinese Academy of Sciences.

  1. Molecular and cellular characteristics of hybrid vigour in a commercial hybrid of Chinese cabbage.

    PubMed

    Saeki, Natsumi; Kawanabe, Takahiro; Ying, Hua; Shimizu, Motoki; Kojima, Mikiko; Abe, Hiroshi; Okazaki, Keiichi; Kaji, Makoto; Taylor, Jennifer M; Sakakibara, Hitoshi; Peacock, W James; Dennis, Elizabeth S; Fujimoto, Ryo

    2016-02-17

    Heterosis or hybrid vigour is a phenomenon in which hybrid progeny exhibit superior performance compared to their parental inbred lines. Most commercial Chinese cabbage cultivars are F1 hybrids and their level of hybrid vigour is of critical importance and is a key selection criterion in the breeding system. We have characterized the heterotic phenotype of one F1 hybrid cultivar of Chinese cabbage and its parental lines from early- to late-developmental stages of the plants. Hybrid cotyledons are larger than those of the parents at 4 days after sowing and biomass in the hybrid, determined by the fresh weight of leaves, is greater than that of the larger parent line by approximately 20% at 14 days after sowing. The final yield of the hybrid harvested at 63 days after sowing is 25% greater than the yield of the better parent. The larger leaves of the hybrid are a consequence of increased cell size and number of the photosynthetic palisade mesophyll cells and other leaf cells. The accumulation of plant hormones in the F1 was within the range of the parental levels at both 2 and 10 days after sowing. Two days after sowing, the expression levels of chloroplast-targeted genes in the cotyledon cells were upregulated in the F1 hybrid relative to their mid parent values. Shutdown of chlorophyll biosynthesis in the cotyledon by norflurazon prevented the increased leaf area in the F1 hybrid. In the cotyledons of F1 hybrids, chloroplast-targeted genes were upregulated at 2 days after sowing. The increased activity levels of this group of genes suggested that their differential transcription levels could be important for establishing early heterosis but the increased transcription levels were transient. Inhibition of the photosynthetic process in the cotyledon reduced heterosis in later seedling stages. These observations suggest early developmental events in the germinating seedling of the hybrid may be important for later developmental vigour and yield advantage.

  2. Hybrid EEG-fNIRS-Based Eight-Command Decoding for BCI: Application to Quadcopter Control.

    PubMed

    Khan, Muhammad Jawad; Hong, Keum-Shik

    2017-01-01

    In this paper, a hybrid electroencephalography-functional near-infrared spectroscopy (EEG-fNIRS) scheme to decode eight active brain commands from the frontal brain region for brain-computer interface is presented. A total of eight commands are decoded by fNIRS, as positioned on the prefrontal cortex, and by EEG, around the frontal, parietal, and visual cortices. Mental arithmetic, mental counting, mental rotation, and word formation tasks are decoded with fNIRS, in which the selected features for classification and command generation are the peak, minimum, and mean ΔHbO values within a 2-s moving window. In the case of EEG, two eyeblinks, three eyeblinks, and eye movement in the up/down and left/right directions are used for four-command generation. The features in this case are the number of peaks and the mean of the EEG signal during 1 s window. We tested the generated commands on a quadcopter in an open space. An average accuracy of 75.6% was achieved with fNIRS for four-command decoding and 86% with EEG for another four-command decoding. The testing results show the possibility of controlling a quadcopter online and in real-time using eight commands from the prefrontal and frontal cortices via the proposed hybrid EEG-fNIRS interface.

  3. Embryonic development and inviability phenotype of chicken-Japanese quail F1 hybrids

    PubMed Central

    Ishishita, Satoshi; Kinoshita, Keiji; Nakano, Mikiharu; Matsuda, Yoichi

    2016-01-01

    Interspecific hybrid incompatibility, including inviability and sterility, is important in speciation; however, its genetic basis remains largely unknown in vertebrates. Crosses between male chickens and female Japanese quails using artificial insemination can generate intergeneric hybrids; however, the hatching rate is low, and hatched hybrids are only sterile males. Hybrid development is arrested frequently during the early embryonic stages, and the sex ratio of living embryos is male-biased. However, the development and sex ratio of hybrid embryos have not been comprehensively analyzed. In the present study, we observed delayed embryonic development of chicken-quail hybrids during the early stage, compared with that of chickens and quails. The survival rate of hybrids decreased markedly during the blastoderm-to-pre-circulation stage and then decreased gradually through the subsequent stages. Hybrid females were observed at more than 10 d of incubation; however, the sex ratio of hybrids became male-biased from 10 d of incubation. Severely malformed embryos were observed frequently in hybrids. These results suggest that developmental arrest occurs at various stages in hybrid embryos, including a sexually non-biased arrest during the early stage and a female-biased arrest during the late stage. We discuss the genetic basis for hybrid inviability and its sex bias. PMID:27199007

  4. Development of Algal Interspecies Correlation Estimation Models for Chemical Hazard Assessment

    EPA Science Inventory

    Web-based Interspecies Correlation Estimation (ICE) is an application developed to predict the acute toxicity of a chemical from 1 species to another taxon. Web-ICE models use the acute toxicity value for a surrogate species to predict effect values for other species, thus potent...

  5. Observation of superconducting vortex clusters in S/F hybrids

    DOE PAGES

    Di Giorgio, C.; Bobba, F.; Cucolo, A. M.; ...

    2016-12-09

    While Abrikosov vortices repel each other and form a uniform vortex lattice in bulk type-II superconductors, strong confinement potential profoundly affects their spatial distribution eventually leading to vortex cluster formation. The confinement could be induced by the geometric boundaries in mesoscopic-size superconductors or by the spatial modulation of the magnetic field in superconductor/ ferromagnet (S/F) hybrids. Here we study the vortex confinement in S/F thin film heterostructures and we observe that vortex clusters appear near magnetization inhomogeneities in the ferromagnet, called bifurcations. We use magnetic force microscopy to image magnetic bifurcations and superconducting vortices, while high resolution scanning tunneling microscopymore » is used to obtain detailed information of the local electronic density of states outside and inside the vortex cluster. We find an intervortex spacing at the bifurcation shorter than the one predicted for the same superconductor in a uniform magnetic field equal to the thermodynamical upper critical field H c2. This result is due to a local enhanced stray field and a competition between vortex-vortex repulsion and Lorentz force. Here, our findings suggest that special magnetic topologies could result in S/F hybrids that support superconductivity even when locally the vortex density exceeds the thermodynamic critical threshold value beyond which the superconductivity is destroyed.« less

  6. Observation of superconducting vortex clusters in S/F hybrids.

    PubMed

    Di Giorgio, C; Bobba, F; Cucolo, A M; Scarfato, A; Moore, S A; Karapetrov, G; D'Agostino, D; Novosad, V; Yefremenko, V; Iavarone, M

    2016-12-09

    While Abrikosov vortices repel each other and form a uniform vortex lattice in bulk type-II superconductors, strong confinement potential profoundly affects their spatial distribution eventually leading to vortex cluster formation. The confinement could be induced by the geometric boundaries in mesoscopic-size superconductors or by the spatial modulation of the magnetic field in superconductor/ferromagnet (S/F) hybrids. Here we study the vortex confinement in S/F thin film heterostructures and we observe that vortex clusters appear near magnetization inhomogeneities in the ferromagnet, called bifurcations. We use magnetic force microscopy to image magnetic bifurcations and superconducting vortices, while high resolution scanning tunneling microscopy is used to obtain detailed information of the local electronic density of states outside and inside the vortex cluster. We find an intervortex spacing at the bifurcation shorter than the one predicted for the same superconductor in a uniform magnetic field equal to the thermodynamical upper critical field H c2 . This result is due to a local enhanced stray field and a competition between vortex-vortex repulsion and Lorentz force. Our findings suggest that special magnetic topologies could result in S/F hybrids that support superconductivity even when locally the vortex density exceeds the thermodynamic critical threshold value beyond which the superconductivity is destroyed.

  7. Observation of superconducting vortex clusters in S/F hybrids

    PubMed Central

    Di Giorgio, C.; Bobba, F.; Cucolo, A. M.; Scarfato, A.; Moore, S. A.; Karapetrov, G.; D’Agostino, D.; Novosad, V.; Yefremenko, V.; Iavarone, M.

    2016-01-01

    While Abrikosov vortices repel each other and form a uniform vortex lattice in bulk type-II superconductors, strong confinement potential profoundly affects their spatial distribution eventually leading to vortex cluster formation. The confinement could be induced by the geometric boundaries in mesoscopic-size superconductors or by the spatial modulation of the magnetic field in superconductor/ferromagnet (S/F) hybrids. Here we study the vortex confinement in S/F thin film heterostructures and we observe that vortex clusters appear near magnetization inhomogeneities in the ferromagnet, called bifurcations. We use magnetic force microscopy to image magnetic bifurcations and superconducting vortices, while high resolution scanning tunneling microscopy is used to obtain detailed information of the local electronic density of states outside and inside the vortex cluster. We find an intervortex spacing at the bifurcation shorter than the one predicted for the same superconductor in a uniform magnetic field equal to the thermodynamical upper critical field Hc2. This result is due to a local enhanced stray field and a competition between vortex-vortex repulsion and Lorentz force. Our findings suggest that special magnetic topologies could result in S/F hybrids that support superconductivity even when locally the vortex density exceeds the thermodynamic critical threshold value beyond which the superconductivity is destroyed. PMID:27934898

  8. Potential for direct interspecies electron transfer in an electric-anaerobic system to increase methane production from sludge digestion.

    PubMed

    Zhao, Zhiqiang; Zhang, Yaobin; Wang, Liying; Quan, Xie

    2015-06-09

    Direct interspecies electron transfer (DIET) between Geobacter species and Methanosaeta species is an alternative to interspecies hydrogen transfer (IHT) in anaerobic digester, which however has not been established in anaerobic sludge digestion as well as in bioelectrochemical systems yet. In this study, it was found that over 50% of methane production of an electric-anaerobic sludge digester was resulted from unknown pathway. Pyrosequencing analysis revealed that Geobacter species were significantly enriched with electrodes. Fluorescence in situ hybridization (FISH) further confirmed that the dominant Geobacter species enriched belonged to Geobacter metallireducens. Together with Methanosaeta species prevailing in the microbial communities, the direct electron exchange between Geobacter species and Methanosaeta species might be an important reason for the "unknown" increase of methane production. Conductivity of the sludge in this electric-anaerobic digester was about 30% higher than that of the sludge in a control digester without electrodes. This study not only revealed for the first time that DIET might be the important mechanism on the methanogenesis of bioelectrochemical system, but also provided a new method to enhance DIET by means of bioelectric enrichment of Geobacter species.

  9. Potential for direct interspecies electron transfer in an electric-anaerobic system to increase methane production from sludge digestion

    PubMed Central

    Zhao, Zhiqiang; Zhang, Yaobin; Wang, Liying; Quan, Xie

    2015-01-01

    Direct interspecies electron transfer (DIET) between Geobacter species and Methanosaeta species is an alternative to interspecies hydrogen transfer (IHT) in anaerobic digester, which however has not been established in anaerobic sludge digestion as well as in bioelectrochemical systems yet. In this study, it was found that over 50% of methane production of an electric-anaerobic sludge digester was resulted from unknown pathway. Pyrosequencing analysis revealed that Geobacter species were significantly enriched with electrodes. Fluorescence in situ hybridization (FISH) further confirmed that the dominant Geobacter species enriched belonged to Geobacter metallireducens. Together with Methanosaeta species prevailing in the microbial communities, the direct electron exchange between Geobacter species and Methanosaeta species might be an important reason for the “unknown” increase of methane production. Conductivity of the sludge in this electric-anaerobic digester was about 30% higher than that of the sludge in a control digester without electrodes. This study not only revealed for the first time that DIET might be the important mechanism on the methanogenesis of bioelectrochemical system, but also provided a new method to enhance DIET by means of bioelectric enrichment of Geobacter species. PMID:26057581

  10. In vitro development and cytological quality of inter-species (porcine→bovine) cloned embryos are affected by trichostatin A-dependent epigenomic modulation of adult mesenchymal stem cells.

    PubMed

    Opiela, J; Samiec, M; Romanek, J

    2017-07-15

    Artificial epigenomic modulation of in vitro cultured mesenchymal stem cells (MSCs) by applying a non-selective HDAC inhibitor, termed TSA, can facilitate more epigenetic reprogramming of transcriptional activity of the somatic cell-descended nuclear genome in NT pig embryos. The results of the present investigation showed that TSA-dependent epigenomic modulation of nuclear donor MSCs highly affects both the in vitro developmental capability and the cytological quality of inter-species (porcine→bovine) cloned embryos. The developmental competences to reach the blastocyst stage among hybrid (porcine→bovine) nuclear-transferred embryos that had been reconstructed with bovine ooplasts and epigenetically modulated porcine MSCs were maintained at a relatively high level. These competences were higher than those noted in studies by other authors, but they were still decreased compared to those of intra-species (porcine) cloned embryos that had been reconstituted with porcine ooplasts and either the cell nuclei of epigenetically transformed MSCs or the cell nuclei of epigenetically non-transformed MSCs. In conclusion, MSCs undergoing TSA-dependent epigenetic transformation were used for the first time as a source of nuclear donor cells not only for inter-species somatic cell cloning in pigs but also for inter-species somatic cell cloning in other livestock species. Moreover, as a result of the current research, efficient sequential physicochemical activation of inter-species nuclear-transferred clonal cybrids derived from bovine ooplasm and porcine MSC nuclei was developed. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Risk for interspecies transmission of zoonotic pathogens during poultry processing and pork production in Peru: A qualitative study.

    PubMed

    Carnero, A M; Kitayama, K; Diaz, D A; Garvich, M; Angulo, N; Cama, V A; Gilman, R H; Bayer, A M

    2018-03-30

    Interspecies transmission of pathogens is an unfrequent but naturally occurring event and human activities may favour opportunities not previously reported. Reassortment of zoonotic pathogens like influenza A virus can result from these activities. Recently, swine and birds have played a central role as "mixing vessels" for epidemic and pandemic events related to strains like H1N1 and H5N1. Unsafe practices in poultry markets and swine farms can lead to interspecies transmission, favouring the emergence of novel strains. Thus, understanding practices that lead to interspecies interactions is crucial. This qualitative study aimed to evaluate poultry processing practices in formal and informal markets and the use of leftovers by swine farmers in three Peruvian cities: Lima (capital), Tumbes (coastal) and Tarapoto (jungle). We conducted 80 direct observations at formal and informal markets and interviewed 15 swine farmers. Processors slaughter and pluck chickens and vendors and/or processors eviscerate chickens. Food safety and hygiene practices were suboptimal or absent, although some heterogeneity was observed between cities and chicken vendors versus processors. Both vendors (76%) and processors (100%) sold the chicken viscera leftovers to swine farmers, representing the main source of chicken viscera for swine farms (53%). Swine farmers fed the chicken viscera to their swine. Chicken viscera cooking times varied widely and were insufficient in some cases. Non-abattoired poultry leads to the sale of poultry leftovers to small-scale swine farms, resulting in indirect but frequent interspecies contacts that can lead to interspecies transmission of bacterial pathogens or the reassortment of influenza A viruses. These interactions are exacerbated by suboptimal safety and hygiene conditions. People involved in these activities constitute an at-risk population who could play a central role in preventing the transmission of pathogens between species. Educational

  12. [18F]FDG imaging of head and neck tumours: comparison of hybrid PET and morphological methods.

    PubMed

    Dresel, S; Grammerstorff, J; Schwenzer, K; Brinkbäumer, K; Schmid, R; Pfluger, T; Hahn, K

    2003-07-01

    The aim of this study was to evaluate fluorine-18 fluorodeoxyglucose ([(18)F]FDG) imaging of head and neck tumours using a second- or third-generation hybrid PET device. Results were compared with the findings of spiral computed tomography (CT) and magnetic resonance imaging (MRI), and, as regards lymph node metastasis, the ultrasound findings. A total of 116 patients with head and neck tumours (83 males and 33 females aged 27-88 years) were examined using a hybrid PET scanner after injection of 185-350 MBq of [(18)F]FDG (Picker Prism 2000 XP-PCD, Marconi Axis gamma-PET(2) AZ). Hybrid PET examinations were performed in list mode using an axial filter. Reconstruction of data was performed iteratively. Ninety-six patients underwent CT using a multislice technique (Siemens Somatom Plus 4, Marconi MX 8000), 18 patients underwent MRI and 100 patients were examined by ultrasound. All findings were verified by histology, which was considered the gold standard, or, in the event of negative histology, by follow-up. Correct diagnosis of the primary or recurrent lesion was made in 73 of 85 patients using the hybrid PET scanner, in 50 of 76 patients on CT and in 7 of 10 patients on MRI. Hybrid PET successfully visualised metastatic disease in cervical lymph nodes in 28 of 34 patients, while 23 of 31 were correctly diagnosed with CT, 3 of 4 with MRI and 30 of 33 with ultrasound. False positive results regarding lymph node metastasis were seen in three patients with hybrid PET, in 14 patients with CT and in 13 patients with ultrasound. MRI yielded no false positive results concerning lymph node metastasis. In one patient, unrecognised metastatic lesions were seen on hybrid PET elsewhere in the body (lung: n=1; bone: n=1). Additional malignant lesions at sites other than the head and neck tumour were found in three patients (one patient with lung cancer, one patient with pelvic metastasis due to a carcinoma of the prostate and one patient with pulmonary metastasis due to breast

  13. Dissection of the complex genetic basis of craniofacial anomalies using haploid genetics and interspecies hybrids in Nasonia wasps

    PubMed Central

    Werren, John H.; Cohen, Lorna B.; Gadau, Juergen; Ponce, Rita; Baudry, Emmanuelle; Lynch, Jeremy A.

    2016-01-01

    The animal head is a complex structure where numerous sensory, structural and alimentary structures are concentrated and integrated, and its ontogeny requires precise and delicate interactions among genes, cells, and tissues. Thus, it is perhaps unsurprising that craniofacial abnormalities are among the most common birth defects in people, or that these defects have a complex genetic basis involving interactions among multiple loci. Developmental processes that depend on such epistatic interactions become exponentially more difficult to study in diploid organisms as the number of genes involved increases. Here, we present hybrid haploid males of the wasp species pair Nasonia vitripennis and Nasonia giraulti, which have distinct male head morphologies, as a genetic model of craniofacial development that possesses the genetic advantages of haploidy, along with many powerful genomic tools. Viable, fertile hybrids can be made between the species, and quantitative trail loci related to shape differences have been identified. In addition, a subset of hybrid males show head abnormalities, including clefting at the midline and asymmetries. Crucially, epistatic interactions among multiple loci underlie several developmental differences and defects observed in the F2 hybrid males. Furthermore, we demonstrate an introgression of a chromosomal region from N. giraulti into N. vitripennis that shows an abnormality in relative eye size, which maps to a region containing a major QTL for this trait. Therefore, the genetic sources of head morphology can, in principle, be identified by positional cloning. Thus, Nasonia is well positioned to be a uniquely powerful model invertebrate system with which to probe both development and complex genetics of craniofacial patterning and defects. PMID:26721604

  14. Next Generation Mapping of Enological Traits in an F2 Interspecific Grapevine Hybrid Family

    PubMed Central

    Sun, Qi; Manns, David C.; Sacks, Gavin L.; Mansfield, Anna Katharine; Luby, James J.; Londo, Jason P.; Reisch, Bruce I.; Cadle-Davidson, Lance E.; Fennell, Anne Y.

    2016-01-01

    In winegrapes (Vitis spp.), fruit quality traits such as berry color, total soluble solids content (SS), malic acid content (MA), and yeast assimilable nitrogen (YAN) affect fermentation or wine quality, and are important traits in selecting new hybrid winegrape cultivars. Given the high genetic diversity and heterozygosity of Vitis species and their tendency to exhibit inbreeding depression, linkage map construction and quantitative trait locus (QTL) mapping has relied on F1 families with the use of simple sequence repeat (SSR) and other markers. This study presents the construction of a genetic map by single nucleotide polymorphisms identified through genotyping-by-sequencing (GBS) technology in an F2 mapping family of 424 progeny derived from a cross between the wild species V. riparia Michx. and the interspecific hybrid winegrape cultivar, ‘Seyval’. The resulting map has 1449 markers spanning 2424 cM in genetic length across 19 linkage groups, covering 95% of the genome with an average distance between markers of 1.67 cM. Compared to an SSR map previously developed for this F2 family, these results represent an improved map covering a greater portion of the genome with higher marker density. The accuracy of the map was validated using the well-studied trait berry color. QTL affecting YAN, MA and SS related traits were detected. A joint MA and SS QTL spans a region with candidate genes involved in the malate metabolism pathway. We present an analytical pipeline for calling intercross GBS markers and a high-density linkage map for a large F2 family of the highly heterozygous Vitis genus. This study serves as a model for further genetic investigations of the molecular basis of additional unique characters of North American hybrid wine cultivars and to enhance the breeding process by marker-assisted selection. The GBS protocols for identifying intercross markers developed in this study can be adapted for other heterozygous species. PMID:26974672

  15. Hybrid male sterility and genome-wide misexpression of male reproductive proteases.

    PubMed

    Gomes, Suzanne; Civetta, Alberto

    2015-07-06

    Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation.

  16. Fingerprinting and genetic purity assessment of F1 barley hybrids and their salt-tolerant parental lines using nSSR molecular markers.

    PubMed

    Ben Romdhane, Mériam; Riahi, Leila; Jardak, Rahma; Ghorbel, Abdelwahed; Zoghlami, Nejia

    2018-01-01

    Hybridity and the genuineness of hybrids are prominent characteristics for quality control of seeds and thereby for varietal improvement. In the current study, the cross between two local barley genotypes (Ardhaoui: female; Testour: male) previously identified as susceptible/tolerant to salt stress in Tunisia was achieved. The hybrid genetic purity of the generated F 1 putative hybrids and the fingerprinting of the parents along with their offspring were assessed using a set of 17 nuclear SSR markers. Among the analyzed loci, 11 nSSR were shown polymorphic among the parents and their offspring. Based on the applied 11 polymorphic SSR loci, a total of 28 alleles were detected with an average of 2.54 alleles per locus. The locus HVM33 presented the highest number of alleles. The highest polymorphism information content value was detected for the locus HVM33 (0.6713) whereas the lowest PIC value (0.368) was revealed by the loci BMAC0156 , EBMAC0970 and BMAG0013 with a mean value of 0.4619. The probabilities of identical genotypes PI for the 11 microsatellite markers were 8.63 × 10 -7 . Banding patterns among parents and hybrids showed polymorphic fragments. The 11 SSR loci had produced unique fingerprints for each analyzed genotype and segregate between the two parental lines and their four hybrids. Parentage analysis confirms the hybrid purity of the four analyzed genotypes. Six Tunisian barley accessions were used as an outgroup in the multivariate analysis to confirm the efficiency of the employed 11 nSSR markers in genetic differentiation among various barley germplasms. Thus, neighbor joining and factorial analysis revealed clearly the discrimination among the parental lines, the four hybrids and the outgroup accessions. Out of the detected polymorphic 11 nuclear SSR markers, a set of five markers ( HVM33 , WMC1E8 , BMAC0154 , BMAC0040 and BMAG0007 ) were shown to be sufficient and informative enough to discriminate among the six genotypes representing the two

  17. Gonad morphogenesis defects drive hybrid male sterility in asymmetric hybrid breakdown of Caenorhabditis nematodes

    PubMed Central

    Dey, Alivia; Jin, Qi; Chen, Yen-Chu; Cutter, Asher D.

    2014-01-01

    Determining the causes and evolution of reproductive barriers to gene flow between populations, speciation, is the key to understanding the origin of diversity in nature. Many species manifest hybrid breakdown when they intercross, characterized by increasingly exacerbated problems in later generations of hybrids. Recently, Caenorhabditis nematodes have emerged as a genetic model for studying speciation, and here we investigate the nature and causes of hybrid breakdown between C. remanei and C. latens. We quantify partial F1 hybrid inviability and extensive F2 hybrid inviability; the ~75% F2 embryonic arrest occurs primarily during gastrulation or embryonic elongation. Moreover, F1 hybrid males exhibit Haldane’s rule asymmetrically for both sterility and inviability, being strongest when C. remanei serves as maternal parent. We show that the mechanism by which sterile hybrid males are incapable of transferring sperm or a copulatory plug involves defective gonad morphogenesis, which we hypothesize results from linker cell defects in migration and/or cell death during development. This first documented case of partial hybrid male sterility in Caenorhabditis follows expectations of Darwin’s corollary to Haldane’s rule for asymmetric male fitness, providing a powerful foundation for molecular dissection of intrinsic reproductive barriers and divergence of genetic pathways controlling organ morphogenesis. PMID:25196892

  18. Gonad morphogenesis defects drive hybrid male sterility in asymmetric hybrid breakdown of Caenorhabditis nematodes.

    PubMed

    Dey, Alivia; Jin, Qi; Chen, Yen-Chu; Cutter, Asher D

    2014-01-01

    Determining the causes and evolution of reproductive barriers to gene flow between populations, speciation, is the key to understanding the origin of diversity in nature. Many species manifest hybrid breakdown when they intercross, characterized by increasingly exacerbated problems in later generations of hybrids. Recently, Caenorhabditis nematodes have emerged as a genetic model for studying speciation, and here we investigate the nature and causes of hybrid breakdown between Caenorhabditis remanei and C. latens. We quantify partial F1 hybrid inviability and extensive F2 hybrid inviability; the ~75% F2 embryonic arrest occurs primarily during gastrulation or embryonic elongation. Moreover, F1 hybrid males exhibit Haldane's rule asymmetrically for both sterility and inviability, being strongest when C. remanei serves as maternal parent. We show that the mechanism by which sterile hybrid males are incapable of transferring sperm or a copulatory plug involves defective gonad morphogenesis, which we hypothesize results from linker cell defects in migration and/or cell death during development. This first documented case of partial hybrid male sterility in Caenorhabditis follows expectations of Darwin's corollary to Haldane's rule for asymmetric male fitness, providing a powerful foundation for molecular dissection of intrinsic reproductive barriers and divergence of genetic pathways controlling organ morphogenesis. © 2014 Wiley Periodicals, Inc.

  19. Observation of Interspecies Ion Separation in Inertial-Confinement-Fusion Implosions via Imaging X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Joshi, Tirtha Raj

    2016-10-01

    Interspecies ion separation has been proposed as a yield-degradation mechanism in inertial-confinement-fusion (ICF) experiments. We present direct experimental evidence of interspecies ion separation in direct-drive ICF experiments performed at the OMEGA laser facility. These experiments were designed based on the fact that interspecies ion thermo-diffusion would be strongest for species with large mass and charge difference. The targets were spherical plastic shells filled with D2 and Ar (1% by atom). Ar K-shell spectral features were observed primarily between the time of first-shock convergence and slightly before neutron bang time, using a time- and space-integrated spectrometer, streaked crystal spectrometer, and two gated multi-monochromatic X-ray imagers fielded along quasi-orthogonal lines-of-sight. Detailed spectroscopic analyses of spatially resolved Ar K-shell lines reveal deviation from the initial 1%-Ar gas fill and show both Ar-concentration enhancement and depletion at different times and radial positions of the implosion. The experimental results are interpreted with radiation-hydrodynamic simulations that include recently implemented, first-principles models of interspecies ion diffusion. The experimentally inferred Ar-atom-fraction profiles agree gently with calculated profiles associated with the incoming and rebounding first shock. This work was done in collaboration with P. Hakel, S. C. Hsu, E. L. Vold, M. J. Schmitt, N. M. Hoffman, R. M. Rauenzahn, G. Kagan, X.-Z. Tang, Y. Kim, and H. W. Herrmann of LANL, and R. C. Mancini of UNR. LA-UR-16-24804. Supported by the LANL ICF and ASC Programs under US-DoE contract no. DE-AC52-06NA25396.

  20. Interspecies variation of Kitasatospora recifensis endophytic from yam bean producing thermostable amylases in alternative media.

    PubMed

    Stamford, Tania Lucia Montenegro; Stamford, Thayza Christina Montenegro; Stamford, Newton Pereira; Santos, Carolina Etienne Rosália Silva; de Lyra, Maria do Carmo Catanho Pereira; Ha-Park, Yong; Bae, Jin-Won; Araújo, Janete Magali

    2007-12-01

    An endophytic actinomycete isolated from tubers of yam beam (Pachyrhizus erosus L. Urban) was classified as a novel species nominated Kitasatospora recifensis based in phenotypic and genotypic analysis (16S rDNA gene sequence). Monosporic culture using specific ISP2 media revealed three interspecies, which were identified by DNA southern hybridization (Wild strain 13817 W, Aerial Mycelium strain 13817 AM and Vegetative Mycelium strain 13817 VM). The strains were tested for the production of amylolitic enzymes in alternative media. Maximum yields for both enzymes were observed in starch-casein. Higher α-amylase was obtained with strain 13817 W in starch-urea, and amyloglucosidase with strain 13817 AM in starch-ammonium that are economic sources and may be important for industrial purposes. Type strain (DAUFPE 13817(T) = KCTC 9972(T )= DSM 44943(T)).

  1. Development of Interspecies Correlation Models for Petroleum Hydrocarbons

    EPA Science Inventory

    Estimating the consequences of petroleum products to water column organisms has commonly been hampered by limited acute toxicity data, which exists only for a relatively small number of test species. In this study, we developed petroleum-specific Interspecies Correlation Estimati...

  2. A comparison between Holstein-Friesian and Jersey dairy cows and their F(1) hybrid on milk fatty acid composition under grazing conditions.

    PubMed

    Palladino, R A; Buckley, F; Prendiville, R; Murphy, J J; Callan, J; Kenny, D A

    2010-05-01

    The objective of this study was to investigate the effect of 2 breeds, Holstein and Jersey, and their F(1) hybrid (Jersey x Holstein) on milk fatty acid (FA) concentrations under grazing conditions, especially conjugated linoleic acid (CLA) and n-3 polyunsaturated fatty acids because of their importance to human health. Eighty-one cows (27 per breed grouping) were allocated a predominantly perennial ryegrass pasture. Samples were collected over 2 periods (June and July). Breed affected dry matter intake and milk production and composition. Holstein cows had the highest dry matter intake (18.4+/-0.40kg of DM/d) and milk production (21.1+/-0.53kg of DM/d). Holstein and Jersey x Holstein cows had similar 4% fat corrected milk, fat yield, and protein yield; with the exception of fat yield, these were all higher than for Jersey cows. Milk fat concentration was highest for Jersey cows and lowest for Holstein cows, with the hybrid cows intermediate. Total FA and linolenic acid intake (1.09+/-0.023 and 0.58+/-0.012 kg/d, respectively) were highest for Holstein cows. In terms of milk FA, Holstein cows had higher contents of C14:1, cis-9 C18:1 and linoleic acid. In turn, Jersey and Jersey x Holstein cows had higher content of C16:0. Milk concentrations of neither the cis-9,trans-11 isomer of CLA nor its precursor, vaccenic acid, were affected by breed. Nevertheless, large variation between individual animals within breed grouping was observed for CLA and estimated Delta(9)-desaturase activity. There was some evidence for a negative heterotic effect on milk concentration of CLA, with the F(1) hybrid cows having lower concentrations compared with the mid parent average. Plasma FA profile did not accurately reflect differences in milk FA composition. In conclusion, there was little evidence for either breed or beneficial heterotic effects on milk FA content with human health-promoting potential, though significant within-breed, interanimal variation was observed. Copyright 2010

  3. F γ: A new observable for photon-hadron discrimination in hybrid air shower events

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

    Niechciol, M.; Risse, M.; Ruehl, P.

    To semore » arch for ultra-high-energy photons in primary cosmic rays, air shower observables are needed that allow a good separation between primary photons and primary hadrons. In this paper, we present a new observable, F γ, which can be extracted from ground-array data in hybrid events, where simultaneous measurements of the longitudinal and the lateral shower profile are performed. The observable is based on a template fit to the lateral distribution measured by the ground array with the template taking into account the complementary information from the measurement of the longitudinal profile, i.e. the primary energy and the geometry of the shower. F γ shows a very good photon-hadron separation, which is even superior to the separation given by the well-known X max observable (the atmospheric depth of the shower maximum). At energies around 1 EeV (10 EeV), F γ provides a background rejection better than 97.8 % (99.9 %) at a signal efficiency of 50 %. Advantages of the observable F γ are its technical stability with respect to irregularities in the ground array (i.e. missing or temporarily non-operating stations) and that it can be applied over the full energy range accessible to the air shower detector, down to its threshold energy. Finally and furthermore, F γ complements nicely to X max such that both observables can well be combined to achieve an even better discrimination power, exploiting the rich information available in hybrid events.« less

  4. F γ: A new observable for photon-hadron discrimination in hybrid air shower events

    DOE PAGES

    Niechciol, M.; Risse, M.; Ruehl, P.; ...

    2017-10-21

    To semore » arch for ultra-high-energy photons in primary cosmic rays, air shower observables are needed that allow a good separation between primary photons and primary hadrons. In this paper, we present a new observable, F γ, which can be extracted from ground-array data in hybrid events, where simultaneous measurements of the longitudinal and the lateral shower profile are performed. The observable is based on a template fit to the lateral distribution measured by the ground array with the template taking into account the complementary information from the measurement of the longitudinal profile, i.e. the primary energy and the geometry of the shower. F γ shows a very good photon-hadron separation, which is even superior to the separation given by the well-known X max observable (the atmospheric depth of the shower maximum). At energies around 1 EeV (10 EeV), F γ provides a background rejection better than 97.8 % (99.9 %) at a signal efficiency of 50 %. Advantages of the observable F γ are its technical stability with respect to irregularities in the ground array (i.e. missing or temporarily non-operating stations) and that it can be applied over the full energy range accessible to the air shower detector, down to its threshold energy. Finally and furthermore, F γ complements nicely to X max such that both observables can well be combined to achieve an even better discrimination power, exploiting the rich information available in hybrid events.« less

  5. Activation of interspecies-hybrid Rubisco enzymes to assess different models for the Rubisco-Rubisco activase interaction.

    PubMed

    Wachter, Rebekka M; Salvucci, Michael E; Carmo-Silva, A Elizabete; Barta, Csengele; Genkov, Todor; Spreitzer, Robert J

    2013-11-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is prone to inactivation from non-productive binding of sugar-phosphates. Reactivation of Rubisco requires conformational remodeling by a specific chaperone, Rubisco activase. Rubisco activase from tobacco and other plants in the family Solanaceae is an inefficient activator of Rubisco from non-Solanaceae plants and from the green alga Chlamydomonas reinhardtii. To determine if the Rubisco small subunit plays a role in the interaction with Rubisco activase, a hybrid Rubisco (SSNT) composed of tobacco small subunits and Chlamydomonas large subunits was constructed. The SSNT hybrid, like other hybrid Rubiscos containing plant small subunits, supported photoautotrophic growth in Chlamydomonas, but growth in air was much slower than for cells containing wild-type Rubisco. The kinetic properties of the SSNT hybrid Rubisco were similar to the wild-type enzyme, indicating that the poor growth in air was probably caused by disruption of pyrenoid formation and the consequent impairment of the CO2concentrating mechanism. Recombinant Rubisco activase from Arabidopsis activated the SSNT hybrid Rubisco and hybrid Rubiscos containing spinach and Arabidopsis small subunits at rates similar to the rates with wild-type Rubisco. However, none of the hybrid Rubiscos was activated by tobacco Rubisco activase. That replacement of Chlamydomonas small subunits with plant small subunits does not affect the species-specific interaction between Rubisco and Rubisco activase suggests that the association is not dominated by the small subunits that surround the Rubisco central solvent channel. Therefore, the geometry of a side-on binding mode is more consistent with the data than a top-on or ring-stacking binding mode.

  6. Hybrid male sterility and genome-wide misexpression of male reproductive proteases

    PubMed Central

    Gomes, Suzanne; Civetta, Alberto

    2015-01-01

    Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation. PMID:26146165

  7. Interspecies Chimerism with Mammalian Pluripotent Stem Cells.

    PubMed

    Wu, Jun; Platero-Luengo, Aida; Sakurai, Masahiro; Sugawara, Atsushi; Gil, Maria Antonia; Yamauchi, Takayoshi; Suzuki, Keiichiro; Bogliotti, Yanina Soledad; Cuello, Cristina; Morales Valencia, Mariana; Okumura, Daiji; Luo, Jingping; Vilariño, Marcela; Parrilla, Inmaculada; Soto, Delia Alba; Martinez, Cristina A; Hishida, Tomoaki; Sánchez-Bautista, Sonia; Martinez-Martinez, M Llanos; Wang, Huili; Nohalez, Alicia; Aizawa, Emi; Martinez-Redondo, Paloma; Ocampo, Alejandro; Reddy, Pradeep; Roca, Jordi; Maga, Elizabeth A; Esteban, Concepcion Rodriguez; Berggren, W Travis; Nuñez Delicado, Estrella; Lajara, Jeronimo; Guillen, Isabel; Guillen, Pedro; Campistol, Josep M; Martinez, Emilio A; Ross, Pablo Juan; Izpisua Belmonte, Juan Carlos

    2017-01-26

    Interspecies blastocyst complementation enables organ-specific enrichment of xenogenic pluripotent stem cell (PSC) derivatives. Here, we establish a versatile blastocyst complementation platform based on CRISPR-Cas9-mediated zygote genome editing and show enrichment of rat PSC-derivatives in several tissues of gene-edited organogenesis-disabled mice. Besides gaining insights into species evolution, embryogenesis, and human disease, interspecies blastocyst complementation might allow human organ generation in animals whose organ size, anatomy, and physiology are closer to humans. To date, however, whether human PSCs (hPSCs) can contribute to chimera formation in non-rodent species remains unknown. We systematically evaluate the chimeric competency of several types of hPSCs using a more diversified clade of mammals, the ungulates. We find that naïve hPSCs robustly engraft in both pig and cattle pre-implantation blastocysts but show limited contribution to post-implantation pig embryos. Instead, an intermediate hPSC type exhibits higher degree of chimerism and is able to generate differentiated progenies in post-implantation pig embryos. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The growth performance of F1 transgenic mutiara catfish

    NASA Astrophysics Data System (ADS)

    Iskandar; Buwono, I. D.; Agung, M. U. K.

    2018-04-01

    The growth of catfish (African or Sangkuriang strain) these days is tend to decreased. One of the solutions due to this problem is to improve the genetics of growth using transgenesis technology, toward more profitable. The specific objective of the research is to detect the transmission of exogenous GH (African catfish GH inserts) inside the F1 transgenic Mutiara catfish using PCR (Polymerase Chain Reaction) method and to evaluate the growth performance of transgenic Mutiara catfish made using the parameters of feed conversion (FCR = Feed Conversion Ratio). Transgenic catfish (strain mutiara) F0 and F1 carried African catfish GH (600 bp) can be produced. Superiority characters of transgenic catfish represented heritability (h2 ) and heterosis (H), indicating that the offspring of hybrid F1 transgenic mutiara catfish had phenotypes rapid growth (h2 = 17.55 % and H = 42.83 %) compared to non-transgenic catfish (h 2 = 10.07 % and H = 18.56 %). Evaluation of the efficiency of feed use parameters feed conversion ratio, shows that F1 transgenic mutiara catfish (FCR = 0.85) more efficient in converting feed into meat.

  9. Environment effects for earliness and grain yield traits in F1 diallel populations of maize (Zea mays L.).

    PubMed

    Ali, Sardar; Khan, Naqib Ullah; Khalil, Iftikhar Hussain; Iqbal, Muhammad; Gul, Samrin; Ahmed, Sheraz; Ali, Naushad; Sajjad, Mohammad; Afridi, Khilwat; Ali, Imtiaz; Khan, Shah Masaud

    2017-10-01

    Five maize inbred lines, 20 F 1 diallel hybrids and two check genotypes were evaluated through genotype × environment interaction (GEI) and GGE biplot for earliness and yield traits at four locations. Genotype, environment and GEI showed highly significant differences for all the traits. In total sum of squares, environment and genotype played a primary role, followed by GEI. Larger effects of environment and genotype to total variation influence the earliness and yield traits. However, according to the GGE biplot, the first two principal components (PC1 and PC2) explained 95% of the variation caused by GEI. GGE biplot confirmed the differential response of genotypes across environments. F 1 hybrid SWAJK-1 × FRHW-3 had better stability, with a good yield, and was considered an ideal genotype. F 1 hybrid FRHW-2 × FRHW-1 showed more earliness at CCRI and Haripur, followed by PSEV3 × FRHW-2 and its reciprocal at Swat and Mansehra, respectively. F 1 hybrids FRHW-1 × SWAJK-1, PSEV3 × SWAJK-1 and SWAJK-1 × FRHW-3 at Mansehra and Swat produced maximum grain yield, followed by SWAJK-1 × FRHW-1 and PSEV3 × FRHW-1 at Haripur and CCRI, respectively. Overall, maize genotypes showed early maturity in plain areas (CCRI and Haripur) but higher yield in hilly areas (Mansehra and Swat). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Cloning Endangered Felids by Interspecies Somatic Cell Nuclear Transfer.

    PubMed

    Gómez, Martha C; Pope, C Earle

    2015-01-01

    In 2003, the first wild felid was produced by interspecies somatic cell nuclear transfer. Since then other wild felid clone offspring have been produced by using the same technique with minor modifications. This chapter describes detailed protocols used in our laboratory for (1) the isolation, culture, and preparation of fibroblast cells as donor nucleus, and (2) embryo reconstruction with domestic cat enucleated oocytes to produce cloned embryos that develop to the blastocyst stage in vitro and, after transfer into synchronized recipients, establish successful pregnancies.

  11. Tweedie convergence: a mathematical basis for Taylor's power law, 1/f noise, and multifractality.

    PubMed

    Kendal, Wayne S; Jørgensen, Bent

    2011-12-01

    Plants and animals of a given species tend to cluster within their habitats in accordance with a power function between their mean density and the variance. This relationship, Taylor's power law, has been variously explained by ecologists in terms of animal behavior, interspecies interactions, demographic effects, etc., all without consensus. Taylor's law also manifests within a wide range of other biological and physical processes, sometimes being referred to as fluctuation scaling and attributed to effects of the second law of thermodynamics. 1/f noise refers to power spectra that have an approximately inverse dependence on frequency. Like Taylor's law these spectra manifest from a wide range of biological and physical processes, without general agreement as to cause. One contemporary paradigm for 1/f noise has been based on the physics of self-organized criticality. We show here that Taylor's law (when derived from sequential data using the method of expanding bins) implies 1/f noise, and that both phenomena can be explained by a central limit-like effect that establishes the class of Tweedie exponential dispersion models as foci for this convergence. These Tweedie models are probabilistic models characterized by closure under additive and reproductive convolution as well as under scale transformation, and consequently manifest a variance to mean power function. We provide examples of Taylor's law, 1/f noise, and multifractality within the eigenvalue deviations of the Gaussian unitary and orthogonal ensembles, and show that these deviations conform to the Tweedie compound Poisson distribution. The Tweedie convergence theorem provides a unified mathematical explanation for the origin of Taylor's law and 1/f noise applicable to a wide range of biological, physical, and mathematical processes, as well as to multifractality.

  12. Inter-Species Grafting Caused Extensive and Heritable Alterations of DNA Methylation in Solanaceae Plants

    PubMed Central

    Lin, Yan; Ma, Yiqiao; Liu, Gang; Yu, Xiaoming; Zhong, Silin; Liu, Bao

    2013-01-01

    Background Grafting has been extensively used to enhance the performance of horticultural crops. Since Charles Darwin coined the term “graft hybrid” meaning that asexual combination of different plant species may generate products that are genetically distinct, highly discrepant opinions exist supporting or against the concept. Recent studies have documented that grafting enables exchanges of both RNA and DNA molecules between the grafting partners, thus providing a molecular basis for grafting-induced genetic variation. DNA methylation is known as prone to alterations as a result of perturbation of internal and external conditions. Given characteristics of grafting, it is interesting to test whether the process may cause an alteration of this epigenetic marker in the grafted organismal products. Methodology/Principal Findings We analyzed relative global DNA methylation levels and locus-specific methylation patterns by the MSAP marker and locus-specific bisulfite-sequencing in the seed plants (wild-type controls), self- and hetero-grafted scions/rootstocks, selfed progenies of scions and their seed-plant controls, involving three Solanaceae species. We quantified expression of putative genes involved in establishing and/or maintaining DNA methylation by q-(RT)-PCR. We found that (1) hetero-grafting caused extensive alteration of DNA methylation patterns in a locus-specific manner, especially in scions, although relative methylation levels remain largely unaltered; (2) the altered methylation patterns in the hetero-grafting-derived scions could be inherited to sexual progenies with some sites showing further alterations or revisions; (3) hetero-grafting caused dynamic changes in steady-state transcript abundance of genes encoding for a set of enzymes functionally relevant to DNA methylation. Conclusions/Significance Our results demonstrate that inter-species grafting in plants could produce extensive and heritable alterations in DNA methylation. We suggest that

  13. Enabling interspecies epigenomic comparison with CEpBrowser.

    PubMed

    Cao, Xiaoyi; Zhong, Sheng

    2013-05-01

    We developed the Comparative Epigenome Browser (CEpBrowser) to allow the public to perform multi-species epigenomic analysis. The web-based CEpBrowser integrates, manages and visualizes sequencing-based epigenomic datasets. Five key features were developed to maximize the efficiency of interspecies epigenomic comparisons. CEpBrowser is a web application implemented with PHP, MySQL, C and Apache. URL: http://www.cepbrowser.org/.

  14. Constructing biomolecular motor-powered hybrid NEMS devices

    NASA Astrophysics Data System (ADS)

    Bachand, George D.; Montemagno, Carlo D.

    1999-10-01

    The recognition of many enzymes as nanoscale molecular motors has allowed for the potential creation of hybrid organic/inorganic nano-electro-mechanical (NEMS) devices. The long-range goal of this research is the integration of F1-ATPase with NEMS to produce useful nanoscale devices. A thermostable F1-ATPase coding sequence has been isolated, cloned, and engineered for high-level protein expression. Precise positioning, spacing, and orientation of single F1-ATPase molecules were achieved using patterned nickel arrays. An efficient, accurate, and adaptable assay was developed to assess the performance of single F1- ATPase motors, and confirmed a three-step mechanism of (gamma) subunit rotation during ATP hydrolysis. Further evaluation of the bioengineering and biophysical properties of F1-ATPase currently are being conducted, as well as the construction of an F1-ATPase-powered, hybrid NEMS device. The evolution of this technology will permit the creation of novel classes of nanoscale, hybrid devices.

  15. Hybridization experiments indicate incomplete reproductive isolating mechanism between Fasciola hepatica and Fasciola gigantica.

    PubMed

    Itagaki, T; Ichinomiya, M; Fukuda, K; Fusyuku, S; Carmona, C

    2011-09-01

    Experiments on hybridization between Fasciola hepatica and Fasciola gigantica were carried out to clarify whether a reproductive isolating mechanism appears between the two Fasciola species. Molecular evidence for hybridization was based on the DNA sequence of the internal transcribed spacer 1 (ITS1) region in nuclear ribosomal DNA, which differs between the species. The results suggested that there were not pre-mating but post-mating isolating mechanisms between the two species. However, viable adults of the hybrids F1 and F2 were produced from both parental F. hepatica and F. gigantica. The hybrids inherited phenotypic characteristics such as ratio of body length and width and infectivity to rats from parental Fasciola hepatica and F. gigantica. These findings suggest that reproductive isolation is incomplete between Fasciola hepatica and F. gigantica. Adults of the hybrids F1 and F2 were completely different in mode of reproduction from aspermic Fasciola forms that occur in Asia and seem to be offspring originated from hybridization between F. hepatica and F. gigantica and to reproduce parthenogenetically.

  16. Spatial partitioning and asymmetric hybridization among sympatric coastal steelhead trout (Oncorhynchus mykiss irideus), coastal cutthroat trout (O. clarki clarki) and interspecific hybrids

    USGS Publications Warehouse

    Ostberg, C.O.; Slatton, S.L.; Rodriguez, R.J.

    2004-01-01

    Hybridization between sympatric species provides unique opportunities to examine the contrast between mechanisms that promote hybridization and maintain species integrity. We surveyed hybridization between sympatric coastal steelhead (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki) from two streams in Washington State, Olsen Creek (256 individuals sampled) and Jansen Creek (431 individuals sampled), over a 3-year period. We applied 11 O. mykiss-specific nuclear markers, 11 O. c. clarki-specific nuclear markers and a mitochondrial DNA marker to assess spatial partitioning among species and hybrids and determine the directionality of hybridization. F1 and post-F1 hybrids, respectively, composed an average of 1.2% and 33.6% of the population sampled in Jansen Creek, and 5.9% and 30.4% of the population sampled in Olsen Creek. A modest level of habitat partitioning among species and hybrids was detected. Mitochondrial DNA analysis indicated that all F 1 hybrids (15 from Olsen Creek and five from Jansen Creek) arose from matings between steelhead females and cutthroat males implicating a sneak spawning behaviour by cutthroat males. First-generation cutthroat backcrosses contained O. c. clarki mtDNA more often than expected suggesting natural selection against F1 hybrids. More hybrids were backcrossed toward cutthroat than steelhead and our results indicate recurrent hybridization within these creeks. Age analysis demonstrated that hybrids were between 1 and 4 years old. These results suggest that within sympatric salmonid hybrid zones, exogenous processes (environmentally dependent factors) help to maintain the distinction between parental types through reduced fitness of hybrids within parental environments while divergent natural selection promotes parental types through distinct adaptive advantages of parental phenotypes.

  17. Heterosis and combining ability of F1 hybrid sweet sorghum in Thailand

    USDA-ARS?s Scientific Manuscript database

    Sweet sorghum (Sorghum bicolor (L.) Moench) is a sugar-based biofuel crop that is well-suited to tropical environments. Most sweet sorghum cultivars are open-pollinated, but hybrids could offer yield and seed production advantages. Fifteen hybrids were generated among five female and three male pa...

  18. Hybrid vigour in dogs?

    PubMed

    Nicholas, Frank W; Arnott, Elizabeth R; McGreevy, Paul D

    2016-08-01

    Evidence from other species justifies the hypotheses that useful hybrid vigour occurs in dogs and that it can be exploited for improved health, welfare and fitness for purpose. Unfortunately, most of the relevant published canine studies do not provide estimates of actual hybrid vigour because of inadequate specification of the parentage of mixed-bred dogs. To our knowledge, only three published studies have shed any light on actual hybrid vigour in dogs. There are two reports of actual hybrid vigour between Labrador and Golden retrievers, the first ranging from +2.5% to -6.0% for components of a standardised applied-stimulus behavioural test, and the second being at least +12.4% for chance of graduating as a guide dog. The third study provides a minimum estimate of negative actual hybrid vigour: crossbreds between Labrador retrievers and poodles had a higher prevalence of multifocal retinal dysplasia than the average prevalence in their purebred parent breeds. The lack of estimates of actual hybrid vigour can be overcome by including the exact nature of the cross (e.g. F1, F2 or backcross) and their purebred parental breeds in the specification of mixed-bred dogs. Even if only F1 crossbreds can be categorised, this change would enable researchers to conduct substantial investigations to determine whether hybrid vigour has any utility for dog breeding. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Observation and modeling of interspecies ion separation in inertial confinement fusion implosions via imaging x-ray spectroscopy

    DOE PAGES

    Joshi, Tirtha Raj; Hakel, Peter; Hsu, Scott C.; ...

    2017-03-22

    In this article, we report the first direct experimental evidence of interspecies ion separation in direct-drive inertial confinement fusion experiments performed at the OMEGA laser facility via spectrally, temporally, and spatially resolved imaging x-ray-spectroscopy data [S. C. Hsu et al., Europhys. Lett. 115, 65001 (2016)]. These experiments were designed based on the expectation that interspecies ion thermo-diffusion would be the strongest for species with a large mass and charge difference. The targets were spherical plastic shells filled with D2 and a trace amount of Ar (0.1% or 1% by atom). Ar K-shell spectral features were observed primarily between the timemore » of first-shock convergence and slightly before the neutron bang time, using a time- and space-integrated spectrometer, a streaked crystal spectrometer, and two gated multi-monochromatic x-ray imagers fielded along quasi-orthogonal lines of sight. Detailed spectroscopic analyses of spatially resolved Ar K-shell lines reveal the deviation from the initial 1% Ar gas fill and show both Ar-concentration enhancement and depletion at different times and radial positions of the implosion. The experimental results are interpreted using radiation-hydrodynamic simulations that include recently implemented, first-principles models of interspecies ion diffusion. Lastly, the experimentally inferred Ar-atom fraction profiles agree reasonably with calculated profiles associated with the incoming and rebounding first shock.« less

  20. PIF4-controlled auxin pathway contributes to hybrid vigor in Arabidopsis thaliana.

    PubMed

    Wang, Li; Wu, Li Min; Greaves, Ian K; Zhu, Anyu; Dennis, Elizabeth S; Peacock, W James

    2017-04-25

    F1 hybrids in Arabidopsis and crop species are uniform and high yielding. The F2 generation loses much of the yield advantage and the plants have heterogeneous phenotypes. We generated pure breeding hybrid mimic lines by recurrent selection and also selected a pure breeding small phenotype line. The hybrid mimics are almost completely homozygous with chromosome segments from each parent. Four particular chromosomal segments from C24 and 8 from L er were present in all of the hybrid mimic lines, whereas in the F6 small phenotype line, the 12 segments were each derived from the alternative parent. Loci critical for promoting hybrid vigor may be contained in each of these 12 conserved segments. We have identified genes with similar altered expression in hybrid mimics and F1 plants but not in the small phenotype line. These genes may be critical for the generation of hybrid vigor. Analysis of transcriptomes indicated that increased expression of the transcription factor PHYTOCHROME-INTERACTING FACTOR (PIF4) may contribute to hybrid vigor by targeting the auxin biosynthesis gene YUCCA8 and the auxin signaling gene IAA29 A number of auxin responsive genes promoting leaf growth were up-regulated in the F1 hybrids and hybrid mimics, suggesting that increased auxin biosynthesis and signaling contribute to the hybrid phenotype. The hybrid mimic seeds had earlier germination as did the seeds of the F1 hybrids, indicating cosegregation of the genes for rosette size and the germination trait. Early germination may be an indicator of vigorous hybrids.

  1. PIF4-controlled auxin pathway contributes to hybrid vigor in Arabidopsis thaliana

    PubMed Central

    Wang, Li; Wu, Li Min; Greaves, Ian K.; Zhu, Anyu; Dennis, Elizabeth S.; Peacock, W. James

    2017-01-01

    F1 hybrids in Arabidopsis and crop species are uniform and high yielding. The F2 generation loses much of the yield advantage and the plants have heterogeneous phenotypes. We generated pure breeding hybrid mimic lines by recurrent selection and also selected a pure breeding small phenotype line. The hybrid mimics are almost completely homozygous with chromosome segments from each parent. Four particular chromosomal segments from C24 and 8 from Ler were present in all of the hybrid mimic lines, whereas in the F6 small phenotype line, the 12 segments were each derived from the alternative parent. Loci critical for promoting hybrid vigor may be contained in each of these 12 conserved segments. We have identified genes with similar altered expression in hybrid mimics and F1 plants but not in the small phenotype line. These genes may be critical for the generation of hybrid vigor. Analysis of transcriptomes indicated that increased expression of the transcription factor PHYTOCHROME-INTERACTING FACTOR (PIF4) may contribute to hybrid vigor by targeting the auxin biosynthesis gene YUCCA8 and the auxin signaling gene IAA29. A number of auxin responsive genes promoting leaf growth were up-regulated in the F1 hybrids and hybrid mimics, suggesting that increased auxin biosynthesis and signaling contribute to the hybrid phenotype. The hybrid mimic seeds had earlier germination as did the seeds of the F1 hybrids, indicating cosegregation of the genes for rosette size and the germination trait. Early germination may be an indicator of vigorous hybrids. PMID:28396418

  2. Novel brewing yeast hybrids: creation and application.

    PubMed

    Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

    2017-01-01

    The natural interspecies Saccharomyces cerevisiae × Saccharomyces eubayanus hybrid yeast is responsible for global lager beer production and is one of the most important industrial microorganisms. Its success in the lager brewing environment is due to a combination of traits not commonly found in pure yeast species, principally low-temperature tolerance, and maltotriose utilization. Parental transgression is typical of hybrid organisms and has been exploited previously for, e.g., the production of wine yeast with beneficial properties. The parental strain S. eubayanus has only been discovered recently and newly created lager yeast strains have not yet been applied industrially. A number of reports attest to the feasibility of this approach and artificially created hybrids are likely to have a significant impact on the future of lager brewing. De novo S. cerevisiae × S. eubayanus hybrids outperform their parent strains in a number of respects, including, but not restricted to, fermentation rate, sugar utilization, stress tolerance, and aroma formation. Hybrid genome function and stability, as well as different techniques for generating hybrids and their relative merits are discussed. Hybridization not only offers the possibility of generating novel non-GM brewing yeast strains with unique properties, but is expected to aid in unraveling the complex evolutionary history of industrial lager yeast.

  3. Spectroscopic monitoring of bright A-F type candidate hybrid stars discovered by the Kepler mission

    NASA Astrophysics Data System (ADS)

    Lampens, Patricia; Frémat, Y.; Vermeylen, Lore; De Cat, Peter; Dumortier, Louis; Sódor, Ádám; Sharka, Marek; Bognár, Zsófia

    2018-04-01

    We report on a study of 250 optical spectra for 50 bright A/F-type candidate hybrid pulsating stars from the Kepler field. Most of the spectra have been collected with the high-resolution spectrograph HERMES attached to the Mercator telescope, La Palma. We determined the radial velocities (RVs), projected rotational velocities, fundamental atmospheric parameters and provide a classification based on the appearance of the cross-correlation profiles and the behaviour of the RVs with time in order to find true hybrid pulsators. Additionally, we also detected new spectroscopic binary and multiple systems in our sample and determined the fraction of spectroscopic systems. In order to be able to extend this investigation to the fainter A-F type candidate hybrid stars, various high-quality spectra collected with 3-4 m sized telescopes suitably equipped with a high-resolution spectrograph and furthermore located in the Northern hemisphere would be ideal. This programme could be done using the new instruments installed at the Devasthal Observatory.

  4. An Experimental and Theoretical Study of the Variation of 4f Hybridization Across the La1-xCexIn3 Series

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

    Gout, Delphine J; Gourdon, Olivier; Bauer, E. D.

    2008-01-01

    Crystal structures of a series of La1−xCexIn3 (x = 0.02, 0.2, 0.5, or 0.8) intermetallic compounds have been investigated by both neutron and X-ray diffraction, and their physical properties have been characterized by magnetic susceptibility and specific heat measurements. Our results emphasize atypical atomic displacement parameters (ADP) for the In and the rare-earth sites. Depending on the x value, the In ADP presents either an ellipsoidal elongation (La-rich compounds) or a butterfly-like distortion (Ce-rich compounds). These deformations have been understood by theoretical techniques based on the band theory and are the result of hybridization between conduction electrons and 4f-electrons.

  5. Craniomandibular form and body size variation of first generation mouse hybrids: A model for hominin hybridization.

    PubMed

    Warren, Kerryn A; Ritzman, Terrence B; Humphreys, Robyn A; Percival, Christopher J; Hallgrímsson, Benedikt; Ackermann, Rebecca Rogers

    2018-03-01

    Hybridization occurs in a number of mammalian lineages, including among primate taxa. Analyses of ancient genomes have shown that hybridization between our lineage and other archaic hominins in Eurasia occurred numerous times in the past. However, we still have limited empirical data on what a hybrid skeleton looks like, or how to spot patterns of hybridization among fossils for which there are no genetic data. Here we use experimental mouse models to supplement previous studies of primates. We characterize size and shape variation in the cranium and mandible of three wild-derived inbred mouse strains and their first generation (F 1 ) hybrids. The three parent taxa in our analysis represent lineages that diverged over approximately the same period as the human/Neanderthal/Denisovan lineages and their hybrids are variably successful in the wild. Comparisons of body size, as quantified by long bone measurements, are also presented to determine whether the identified phenotypic effects of hybridization are localized to the cranium or represent overall body size changes. The results indicate that hybrid cranial and mandibular sizes, as well as limb length, exceed that of the parent taxa in all cases. All three F 1 hybrid crosses display similar patterns of size and form variation. These results are generally consistent with earlier studies on primates and other mammals, suggesting that the effects of hybridization may be similar across very different scenarios of hybridization, including different levels of hybrid fitness. This paper serves to supplement previous studies aimed at identifying F 1 hybrids in the fossil record and to introduce further research that will explore hybrid morphologies using mice as a proxy for better understanding hybridization in the hominin fossil record. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Transcriptional Response to Lactic Acid Stress in the Hybrid Yeast Zygosaccharomyces parabailii

    PubMed Central

    2017-01-01

    ABSTRACT Lactic acid has a wide range of applications starting from its undissociated form, and its production using cell factories requires stress-tolerant microbial hosts. The interspecies hybrid yeast Zygosaccharomyces parabailii has great potential to be exploited as a novel host for lactic acid production, due to high organic acid tolerance at low pH and a fermentative metabolism with a high growth rate. Here we used mRNA sequencing (RNA-seq) to analyze Z. parabailii's transcriptional response to lactic acid added exogenously, and we explore the biological mechanisms involved in tolerance. Z. parabailii contains two homeologous copies of most genes. Under lactic acid stress, the two genes in each homeolog pair tend to diverge in expression to a significantly greater extent than under control conditions, indicating that stress tolerance is facilitated by interactions between the two gene sets in the hybrid. Lactic acid induces downregulation of genes related to cell wall and plasma membrane functions, possibly altering the rate of diffusion of lactic acid into cells. Genes related to iron transport and redox processes were upregulated, suggesting an important role for respiratory functions and oxidative stress defense. We found differences in the expression profiles of genes putatively regulated by Haa1 and Aft1/Aft2, previously described as lactic acid responsive in Saccharomyces cerevisiae. Furthermore, formate dehydrogenase (FDH) genes form a lactic acid-responsive gene family that has been specifically amplified in Z. parabailii in comparison to other closely related species. Our study provides a useful starting point for the engineering of Z. parabailii as a host for lactic acid production. IMPORTANCE Hybrid yeasts are important in biotechnology because of their tolerance to harsh industrial conditions. The molecular mechanisms of tolerance can be studied by analyzing differential gene expression under conditions of interest and relating gene expression

  7. Mutations in the novel protocadherin PCDH15 cause Usher syndrome type 1F.

    PubMed

    Alagramam, K N; Yuan, H; Kuehn, M H; Murcia, C L; Wayne, S; Srisailpathy, C R; Lowry, R B; Knaus, R; Van Laer, L; Bernier, F P; Schwartz, S; Lee, C; Morton, C C; Mullins, R F; Ramesh, A; Van Camp, G; Hageman, G S; Woychik, R P; Smith, R J; Hagemen, G S

    2001-08-01

    We have determined the molecular basis for Usher syndrome type 1F (USH1F) in two families segregating for this type of syndromic deafness. By fluorescence in situ hybridization, we placed the human homolog of the mouse protocadherin Pcdh15 in the linkage interval defined by the USH1F locus. We determined the genomic structure of this novel protocadherin, and found a single-base deletion in exon 10 in one USH1F family and a nonsense mutation in exon 2 in the second. Consistent with the phenotypes observed in these families, we demonstrated expression of PCDH15 in the retina and cochlea by RT-PCR and immunohistochemistry. This report shows that protocadherins are essential for maintenance of normal retinal and cochlear function.

  8. Hardwiring microbes via direct interspecies electron transfer: mechanisms and applications.

    PubMed

    Cheng, Qiwen; Call, Douglas F

    2016-08-10

    Multicellular microbial communities are important catalysts in engineered systems designed to treat wastewater, remediate contaminated sediments, and produce energy from biomass. Understanding the interspecies interactions within them is therefore essential to design effective processes. The flow of electrons within these communities is especially important in the determination of reaction possibilities (thermodynamics) and rates (kinetics). Conventional models of electron transfer incorporate the diffusion of metabolites generated by one organism and consumed by a second, frequently referred to as mediated interspecies electron transfer (MIET). Evidence has emerged in the last decade that another method, called direct interspecies electron transfer (DIET), may occur between organisms or in conjunction with electrically conductive materials. Recent research has suggested that DIET can be stimulated in engineered systems to improve desired treatment goals and energy recovery in systems such as anaerobic digesters and microbial electrochemical technologies. In this review, we summarize the latest understanding of DIET mechanisms, the associated microorganisms, and the underlying thermodynamics. We also critically examine approaches to stimulate DIET in engineered systems and assess their effectiveness. We find that in most cases attempts to promote DIET in mixed culture systems do not yield the improvements expected based on defined culture studies. Uncertainties of other processes that may be co-occurring in real systems, such as contaminant sorption and biofilm promotion, need to be further investigated. We conclude by identifying areas of future research related to DIET and its application in biological treatment processes.

  9. Aqueous and Tissue Residue-Based Interspecies Correlation Estimation Models Provide Conservative Hazard Estimates for Aromatic Compounds

    EPA Science Inventory

    Interspecies correlation estimation (ICE) models were developed for 30 nonpolar aromatic compounds to allow comparison of prediction accuracy between 2 data compilation approaches. Type 1 models used data combined across studies, and type 2 models used data combined only within s...

  10. A hybrid method for classifying cognitive states from fMRI data.

    PubMed

    Parida, S; Dehuri, S; Cho, S-B; Cacha, L A; Poznanski, R R

    2015-09-01

    Functional magnetic resonance imaging (fMRI) makes it possible to detect brain activities in order to elucidate cognitive-states. The complex nature of fMRI data requires under-standing of the analyses applied to produce possible avenues for developing models of cognitive state classification and improving brain activity prediction. While many models of classification task of fMRI data analysis have been developed, in this paper, we present a novel hybrid technique through combining the best attributes of genetic algorithms (GAs) and ensemble decision tree technique that consistently outperforms all other methods which are being used for cognitive-state classification. Specifically, this paper illustrates the combined effort of decision-trees ensemble and GAs for feature selection through an extensive simulation study and discusses the classification performance with respect to fMRI data. We have shown that our proposed method exhibits significant reduction of the number of features with clear edge classification accuracy over ensemble of decision-trees.

  11. Exploring the potential of Saccharomyces eubayanus as a parent for new interspecies hybrid strains in winemaking.

    PubMed

    Magalhães, Frederico; Krogerus, Kristoffer; Castillo, Sandra; Ortiz-Julien, Anne; Dequin, Sylvie; Gibson, Brian

    2017-08-01

    Yeast cryotolerance brings some advantages for wine fermentations, including the improved aromatic complexity of white wines. Naturally cold-tolerant strains are generally less adept at wine fermentation but fermentative fitness can potentially be improved through hybridization. Here we studied the potential of using hybrids involving Saccharomyces eubayanus and a S. cerevisiae wine strain for low-temperature winemaking. Through screening the performance in response to variable concentrations of sugar, nitrogen and temperature, we isolated one hybrid strain that exhibited the superior performance. This hybrid strain was propagated and dried in pilot scale and tested for the fermentation of Macabeu and Sauvignon blanc grape musts. We obtained highly viable active dry yeast, which was able to efficiently ferment the grape musts with superior production of aroma active volatiles, in particular, 2-phenylethanol. The genome sequences of the hybrid strains revealed variable chromosome inheritance among hybrids, particularly within the S. cerevisiae subgenome. With the present paper, we expand the knowledge on the potentialities of using S. eubayanus hybrids in industrial fermentation at beverages other than lager beer. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. New developments in microbial interspecies signaling.

    PubMed

    Shank, Elizabeth Anne; Kolter, Roberto

    2009-04-01

    There is a growing appreciation that in addition to well-documented intraspecies quorum sensing systems, small molecules act as signals between microbes of different species. This review will focus on how bacterial small molecules modulate these interspecies interactions. We will particularly emphasize complex relationships such as those between microbes and insects, interactions resulting in non-antagonistic outcomes (i.e. developmental and morphological processes), how co-culture can lead to the discovery of new small molecules, and the use of known compounds to evoke unexpected responses and mediate crosstalk between microbes.

  13. TFDP3 was expressed in coordination with E2F1 to inhibit E2F1-mediated apoptosis in prostate cancer.

    PubMed

    Ma, Yueyun; Xin, Yijuan; Li, Rui; Wang, Zhe; Yue, Qiaohong; Xiao, Fengjing; Hao, Xiaoke

    2014-03-10

    TFDP3 has been previously identified as an inhibitor of E2F molecules. It has been shown to suppress E2F1-induced apoptosis dependent P53 and to play a potential role in carcinogenesis. However, whether it indeed helps cancer cells tolerate apoptosis stress in cancer tissues remains unknown. TFDP3 expression was assessed by RT-PCR, in situ hybridization and immunohistochemistry in normal human tissues, cancer tissues and prostate cancer tissues. The association between TFDP3 and E2F1 in prostate cancer development was analyzed in various stages. Apoptosis was evaluated with annexin-V and propidium iodide staining and flow-cytometry. The results show that, in 96 samples of normal human tissues, TFDP3 could be detected in the cerebrum, esophagus, stomach, small intestine, bronchus, breast, ovary, uterus, and skin, but seldom in the lung, muscles, prostate, and liver. In addition, TFDP3 was highly expressed in numerous cancer tissues, such as brain-keratinous, lung squamous cell carcinoma, testicular seminoma, cervical carcinoma, skin squamous cell carcinoma, gastric adenocarcinoma, liver cancer, and prostate cancer. Moreover, TFDP3 was positive in 23 (62.2%) of 37 prostate cancer samples regardless of stage. Furthermore, immunohistochemistry results show that TFDP3 was always expressed in coordination with E2F1 at equivalent expression levels in prostate cancer tissues, and was highly expressed particularly in samples of high stage. When E2F1 was extrogenously expressed in LNCap cells, TFDP3 could be induced, and the apoptosis induced by E2F1 was significantly decreased. It was demonstrated that TFDP3 was a broadly expressed protein corresponding to E2F1 in human tissues, and suggested that TFDP3 is involved in prostate cancer cell survival by suppressing apoptosis induced by E2F1. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Vocal and visual stimulation, congruence and lateralization affect brain oscillations in interspecies emotional positive and negative interactions.

    PubMed

    Balconi, Michela; Vanutelli, Maria Elide

    2016-01-01

    The present research explored the effect of cross-modal integration of emotional cues (auditory and visual (AV)) compared with only visual (V) emotional cues in observing interspecies interactions. The brain activity was monitored when subjects processed AV and V situations, which represented an emotional (positive or negative), interspecies (human-animal) interaction. Congruence (emotionally congruous or incongruous visual and auditory patterns) was also modulated. electroencephalography brain oscillations (from delta to beta) were analyzed and the cortical source localization (by standardized Low Resolution Brain Electromagnetic Tomography) was applied to the data. Frequency band (mainly low-frequency delta and theta) showed a significant brain activity increasing in response to negative compared to positive interactions within the right hemisphere. Moreover, differences were found based on stimulation type, with an increased effect for AV compared with V. Finally, delta band supported a lateralized right dorsolateral prefrontal cortex (DLPFC) activity in response to negative and incongruous interspecies interactions, mainly for AV. The contribution of cross-modality, congruence (incongruous patterns), and lateralization (right DLPFC) in response to interspecies emotional interactions was discussed at light of a "negative lateralized effect."

  15. Micromechanical Devices to Reduce 1/f Noise in Magnetic Field and Electric Charge Sensors

    NASA Astrophysics Data System (ADS)

    Jaramillo, Gerardo

    1/f noise is present in every aspect of nature. Sensors and read-out electronics have the ultimate detection limit set by the noise floor of the white noise. In order to increase signal-to-noise ratio (SNR) of low frequency signals buried by high 1/f noise, the signal can be up-converted to a high frequency signal that lies in the lower white noise regime of the sensing device. Mechanical modulation can be employed to move low frequency electronic signals to higher frequency region through the use of microresonators. This thesis has two goals: (1) develop and fabricate a hybrid micromechanical-magnetoresistive magnetic field sensor; and (2) design an electrometer to measure currents collected from air streams containing ionized nano-particles. First, we designed magnetoresistive-microelectromechanical systems (MR-MEMS) hybrid devices based on the monolithic integration of magnetic thin films and silicon-on-insulator (SOI) MEMS fabrication techniques. We used MgO-based magnetic tunnel junctions (MTJ) placed on a bulk micromachined silicon MEMS device to form a hybrid sensing device. The MEMS device was used to mechanically modulate the magnetic field signal detected by the MTJ, thereby reducing the effects of 1/f noise on the MTJ's output. Two actuator designs were investigated: cantilever and electrostatic comb-drive. The second component of the thesis presents a MEMS-based electrometer for the detection of small currents from ionized particles in a particle detection system for air-quality monitoring. One method of particle detection ionizes particles and then feeds a stream of charged particles into a Faraday cup electrometer. We replaced the Faraday cup with a filtering porous mesh sensing-electrode coupled to a MEMS electrometer with a noise floor below 1 fA rms. Experiments were conducted with fA level currents produced by 10 nm diameter particles within an airflow of 1.0 L/min. The MEMS electrometer was compared and calibrated using commercial electrometers

  16. Basal and induced granulopoiesis in outbred, F1 hybrid and inbred mice: can inbreeding depression influence the experimental practice?

    PubMed

    Hofer, Michal; Pospísil, Milan; Dusek, Ladislav; Holá, Jirina; Hoferová, Zuzana; Weiterová, Lenka

    2010-08-01

    In this study we examined differences in selected indices of granulopoiesis in outbred, F(1) hybrid and inbred mouse strains. Specifically, serum granulocyte colony-stimulating factor (G-CSF) levels, numbers of marrow granulocyte-macrophage progenitor cells and morphologically recognizable proliferative marrow granulocytic precursor cells were evaluated. These parameters were determined in untreated controls, and in mice exposed either to a non-specific stimulus (injection of saline) or to a granulopoiesis-enhancing stimulus (administration of a cyclooxygenase-2 inhibitor, meloxicam). Lower levels of G-CSF were detectable in the outbred ICR mice, which also demonstrated an enhanced response to both types of the stimuli. Considering the fact that outbred mice are closer to natural mammalian populations, including human ones, the possibility of using outbred mice, instead of the often used inbred strains, for experiments evaluating the effects of pharmacological interventions on hematopoiesis should be investigated.

  17. Interspecific Introgression in Cetaceans: DNA Markers Reveal Post-F1 Status of a Pilot Whale

    PubMed Central

    Miralles, Laura; Lens, Santiago; Rodríguez-Folgar, Antonio; Carrillo, Manuel; Martín, Vidal; Mikkelsen, Bjarni; Garcia-Vazquez, Eva

    2013-01-01

    Visual species identification of cetacean strandings is difficult, especially when dead specimens are degraded and/or species are morphologically similar. The two recognised pilot whale species (Globicephala melas and Globicephala macrorhynchus) are sympatric in the North Atlantic Ocean. These species are very similar in external appearance and their morphometric characteristics partially overlap; thus visual identification is not always reliable. Genetic species identification ensures correct identification of specimens. Here we have employed one mitochondrial (D-Loop region) and eight nuclear loci (microsatellites) as genetic markers to identify six stranded pilot whales found in Galicia (Northwest Spain), one of them of ambiguous phenotype. DNA analyses yielded positive amplification of all loci and enabled species identification. Nuclear microsatellite DNA genotypes revealed mixed ancestry for one individual, identified as a post-F1 interspecific hybrid employing two different Bayesian methods. From the mitochondrial sequence the maternal species was Globicephala melas. This is the first hybrid documented between Globicephala melas and G. macrorhynchus, and the first post-F1 hybrid genetically identified between cetaceans, revealing interspecific genetic introgression in marine mammals. We propose to add nuclear loci to genetic databases for cetacean species identification in order to detect hybrid individuals. PMID:23990883

  18. Molecular Markers for Interspecies Transmission of Avian Influenza Viruses in Mammalian Hosts

    PubMed Central

    Lee, Taehyung

    2017-01-01

    In the last decade, a wide range of avian influenza viruses (AIVs) have infected various mammalian hosts and continuously threaten both human and animal health. It is a result of overcoming the inter-species barrier which is mostly associated with gene reassortment and accumulation of mutations in their gene segments. Several recent studies have shed insights into the phenotypic and genetic changes that are involved in the interspecies transmission of AIVs. These studies have a major focus on transmission from avian to mammalian species due to the high zoonotic potential of the viruses. As more mammalian species have been infected with these viruses, there is higher risk of genetic evolution of these viruses that may lead to the next human pandemic which represents and raises public health concern. Thus, understanding the mechanism of interspecies transmission and molecular determinants through which the emerging AIVs can acquire the ability to transmit to humans and other mammals is an important key in evaluating the potential risk caused by AIVs among humans. Here, we summarize previous and recent studies on molecular markers that are specifically involved in the transmission of avian-derived influenza viruses to various mammalian hosts including humans, pigs, horses, dogs, and marine mammals. PMID:29236050

  19. H5N1 Influenza A Virus PB1-F2 Relieves HAX-1-Mediated Restriction of Avian Virus Polymerase PA in Human Lung Cells.

    PubMed

    Mazel-Sanchez, B; Boal-Carvalho, I; Silva, F; Dijkman, R; Schmolke, M

    2018-06-01

    Highly pathogenic influenza A viruses (IAV) from avian hosts were first reported to directly infect humans 20 years ago. However, such infections are rare events, and our understanding of factors promoting or restricting zoonotic transmission is still limited. One accessory protein of IAV, PB1-F2, was associated with pathogenicity of pandemic and zoonotic IAV. This short (90-amino-acid) peptide does not harbor an enzymatic function. We thus identified host factors interacting with H5N1 PB1-F2, which could explain its importance for virulence. PB1-F2 binds to HCLS1-associated protein X1 (HAX-1), a recently identified host restriction factor of the PA subunit of IAV polymerase complexes. We demonstrate that the PA of a mammal-adapted H1N1 IAV is resistant to HAX-1 imposed restriction, while the PA of an avian-origin H5N1 IAV remains sensitive. We also showed HAX-1 sensitivity for PAs of A/Brevig Mission/1/1918 (H1N1) and A/Shanghai/1/2013 (H7N9), two avian-origin zoonotic IAV. Inhibition of H5N1 polymerase by HAX-1 can be alleviated by its PB1-F2 through direct competition. Accordingly, replication of PB1-F2-deficient H5N1 IAV is attenuated in the presence of large amounts of HAX-1. Mammal-adapted H1N1 and H3N2 viruses do not display this dependence on PB1-F2 for efficient replication in the presence of HAX-1. We propose that PB1-F2 plays a key role in zoonotic transmission of avian H5N1 IAV into humans. IMPORTANCE Aquatic and shore birds are the natural reservoir of influenza A viruses from which the virus can jump into a variety of bird and mammal host species, including humans. H5N1 influenza viruses are a good model for this process. They pose an ongoing threat to human and animal health due to their high mortality rates. However, it is currently unclear what restricts these interspecies jumps on the host side or what promotes them on the virus side. Here we show that a short viral peptide, PB1-F2, helps H5N1 bird influenza viruses to overcome a human restriction

  20. Mitochondrial Recombination and Introgression during Speciation by Hybridization.

    PubMed

    Leducq, Jean-Baptiste; Henault, Mathieu; Charron, Guillaume; Nielly-Thibault, Lou; Terrat, Yves; Fiumera, Heather L; Shapiro, B Jesse; Landry, Christian R

    2017-08-01

    Genome recombination is a major source of genotypic diversity and contributes to adaptation and speciation following interspecies hybridization. The contribution of recombination in these processes has been thought to be largely limited to the nuclear genome because organelles are mostly uniparentally inherited in animals and plants, which prevents recombination. Unicellular eukaryotes such as budding yeasts do, however, transmit mitochondria biparentally, suggesting that during hybridization, both parents could provide alleles that contribute to mitochondrial functions such as respiration and metabolism in hybrid populations or hybrid species. We examined the dynamics of mitochondrial genome transmission and evolution during speciation by hybridization in the natural budding yeast Saccharomyces paradoxus. Using population-scale mitochondrial genome sequencing in two endemic North American incipient species SpB and SpC and their hybrid species SpC*, we found that both parental species contributed to the hybrid mitochondrial genome through recombination. We support our findings by showing that mitochondrial recombination between parental types is frequent in experimental crosses that recreate the early step of this speciation event. In these artificial hybrids, we observed that mitochondrial genome recombination enhances phenotypic variation among diploid hybrids, suggesting that it could play a role in the phenotypic differentiation of hybrid species. Like the nuclear genome, the mitochondrial genome can, therefore, also play a role in hybrid speciation. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Outbreeding depression in hybrids between odd-and even-broodyear pink salmon

    USGS Publications Warehouse

    Gharrett, A.J.; Smoker, W.W.; Reisenbichler, R.R.; Taylor, S.G.

    1999-01-01

    Fewer F2 hybrids between even- and odd-broodline pink salmon (Oncorhynchus gorbuscha), which are lines that are genetically isolated by their strict two-year life cycle, survived than did F2 controls, indicating outbreeding depression. Cryopreserved sperm of 40 broodyear 1990 males and of 40 broodyear 1991 males fertilized equal subsamples of eggs from 40 broodyear 1992 females. Return rates of F1 hybrids (1.73%) and controls (1.63%) in 1994 did not differ significantly (P=0.30). F2 hybrid and control crosses were made from 40 males and 40 females selected at random from each return group. Offspring were differentially marked and released. In 1996, returns differed significantly (P=0.011) between hybrids (n=34, 0.34%) and controls (n=44, 0.42%). The low rate of return of the control fish was similar to the measured return of a much larger group of tagged Auke Creek pink salmon, and probably not an artifact of the experiment. Although no increase in fluctuating asymmetry of paired meristic counts was observed in either F1or F2 hybrids, size and some meristic counts of hybrids exceed measurements of controls, suggesting heterosis for those traits. The observations of decreased survival in F2 hybrids confirm previous work [Gharrett, A.J., Smoker, W.W., 1991. Two generations of hybrids between even- and odd-year pink salmon (O. gorbuscha). Canadian Journal of Fisheries and Aquatic Science 48(9) 1744–1749]. Although genetic divergence between pink salmon broodlines is large and outbreeding depression might be expected in such unlikely hybrids, the results document the occurrence of outbreeding depression in salmon and signal caution in making management and aquacultural decisions that may create the possibility of outbreeding depression in self-sustaining or cultured populations.

  2. Interspecies Transmission of Feline Immunodeficiency Virus from the Domestic Cat to the Tsushima Cat (Felis bengalensis euptilura) in the Wild

    PubMed Central

    Nishimura, Yoshiaki; Goto, Yuko; Yoneda, Kumiko; Endo, Yasuyuki; Mizuno, Takuya; Hamachi, Masaharu; Maruyama, Hiroyuki; Kinoshita, Hirotoshi; Koga, Susumu; Komori, Mitsuru; Fushuku, Seigo; Ushinohama, Kanji; Akuzawa, Masao; Watari, Toshihiro; Hasegawa, Atsuhiko; Tsujimoto, Hajime

    1999-01-01

    Feline immunodeficiency virus (FIV) was isolated from a wild-caught Tsushima cat (Felis bengalensis euptilura), an endangered Japanese nondomestic subspecies of leopard cat (F. bengalensis). Phylogenetic analysis of the env gene sequences indicated that the FIV from the Tsushima cat belonged to a cluster of subtype D FIVs from domestic cats. FIVs from both the Tsushima cat and the domestic cat showed similar levels of replication and cytopathicity in lymphoid cell lines derived from these two species. The results indicated the occurrence of interspecies transmission of FIV from the domestic cat to the Tsushima cat in the wild. PMID:10438892

  3. Ti:sapphire/KrF hybrid laser system generating trains of subterawatt subpicosecond UV pulses

    NASA Astrophysics Data System (ADS)

    Zvorykin, V. D.; Ionin, A. A.; Levchenko, A. O.; Mesyats, G. A.; Seleznev, L. V.; Sinitsyn, D. V.; Ustinovskii, N. N.; Shutov, A. V.

    2014-05-01

    The GARPUN-MTW Ti:sapphire/KrF hybrid laser system is used to investigate different multipass schemes for amplifying trains of ultrashort pulses (USPs) of subpicosecond duration. It is shown that, for an USP repetition period of 3 - 5 ns, which exceeds the gain-medium recovery time (~2 ns), trains are amplified in the same way as single USPs. Due to this, a train can efficiently extract pump energy from the amplifier and sum energies of individual USPs. The energy of a four-USP train, extracted during four passes through the preamplifier and two passes through the final KrF amplifier (4 + 2 scheme), is saturated at a level of 1.6 J and corresponds to maximum USP peak powers of about 0.6 TW. The energy of amplified spontaneous emission (ASE), on the contrary, rapidly increases at a large total gain length Leff ≈ 6 m and is approximately equal to the USP energy. In the (4 + 1) and (2 + 2) schemes the USP energy decreases only slightly, to Eout = 1.3 and 1.2 J, and the ASE fraction is reduced to about 10% and 3%, respectively. USP self-focusing leads to multiple laser beam filamentation and a 200-fold local increase in the radiation intensity in filaments, to ~2 × 1011 W cm-2, a level at which the nonlinear loss in the output CaF2 windows of the KrF amplifier, caused by three-photon absorption, nonlinear scattering, and broadening of the radiation spectrum to a value exceeding the gain band of the KrF laser transition, becomes the main factor determining the saturation of the USP output energy.

  4. SPECIES DIFFERENCES IN ANDROGEN AND ESTROGEN RECEPTOR STRUCTURE AND FUNCTION AMONG VERTEBRATES AND INVERTEBRATES: INTERSPECIES EXTRAPOLATIONS REGARDING ENDOCRINE DISRUPTING CHEMICALS

    EPA Science Inventory

    Species Differences in Androgen and Estrogen Receptor Structure and Function Among Vertebrates and Invertebrates: Interspecies Extrapolations regarding Endocrine Disrupting Chemicals
    VS Wilson1, GT Ankley2, M Gooding 1,3, PD Reynolds 1,4, NC Noriega 1, M Cardon 1, P Hartig1,...

  5. Interspecies scaling of a camptothecin analogue: human predictions for intravenous topotecan using animal data.

    PubMed

    Ahlawat, P; Srinivas, N R

    2008-11-01

    As a class, camptothecin analogues via market entry of topotecan and irinotecan, have shown promise for the treatment of various solid tumours. Topotecan, in particular, was chosen as the substrate for allometric scaling and prediction of human parameter values for both total clearance (CL) and volume of distribution (V(ss)). The availability of published data in mouse, rat, dog, and monkey paved the way for interspecies scaling via allometry. Although it appeared that at a minimum mouse, rat, and dog would reasonably fit in a three-species allometry scale-up, the inclusion of monkey data enabled a better prediction of the human parameter values for total topotecan-e.g., CL: allometric equation: 1.5234W(0.7865); predicted value = 43.04 l h(-1): observed CL = 24-53 l h(-1); V(ss): allometric equation: 1.1939W(1.0208); predicted value = 91.29 litres: observed V(ss) = 66-146 litres. The proximity of the allometric exponent values of CL (0.7885) and V(ss) (1.0208) to the suggested values of 0.75 and 1.00 was not only encouraging, but also confirmed the applicability of interspecies scaling approach for topotecan. The data suggest that allometric scaling approaches with suitable correction factors could potentially be used to predict the human pharmacokinetics of novel CPT analogues prospectively.

  6. ESTIMATION OF CHEMICAL TOXICITY TO WILDLIFE SPECIES USING INTERSPECIES CORRELATION MODELS

    EPA Science Inventory

    Ecological risks to wildlife are typically assessed using toxicity data for relataively few species and with limited understanding of differences in species sensitivity to contaminants. Empirical interspecies correlation models were derived from LD50 values for 49 wildlife speci...

  7. Hybrid Optical Processor

    DTIC Science & Technology

    1990-08-01

    LCTVs) ..................... 17 2.14 JOINT FOURIER TRANSFORM PROCESSOR .................. 18 2.15 HOLOGRAPHIC ASSOCIATIVE MEMORY USING A MICRO ...RADC-TR-90-256 Final Technical Report August1990 AD-A227 163 HYBRID OPTICAL PROCESSOR Dove Electronics, Inc. J.F. Dove, F.T .S. Yu, C. Eldering...ANM SUSUE & FUNDING NUMBERS C - F19628-87-C-0086 HYBRID OPTICAL PROCESSOR PE - 61102F PR - 2305 &AUThNOA TA - J7 J.F. Dove, F.T.S. Yu, C. Eldering WU

  8. Meta-analysis of cannabinoid ligand binding affinity and receptor distribution: interspecies differences

    PubMed Central

    McPartland, J M; Glass, M; Pertwee, R G

    2007-01-01

    A meta-analysis, unlike a literature review, synthesizes previous studies into new results. Pooled data from 211 studies measured ligand binding affinities at human (Hs) or rat (Rn) cannabinoid receptors CB1 and CB2. Cochrane methods were modified for this non-clinical analysis. Meta-regression detected data heterogeneity arising from methodological factors: use of sectioned tissues, lack of PMSF and choice of radioligand. Native brain tissues exhibited greater affinity (lower nM) than transfected cells, but the trend fell short of significance, as did the trend between centrifugation and filtration methods. Correcting for heterogeneity, mean Ki values for Δ9-tetrahydrocannabinol differed significantly between HsCB1 and RnCB1 (25.1 and 42.6 nM, respectively) but not between HsCB1 and HsCB2 (25.1 and 35.2). Mean Kd values for HsCB1, RnCB1 and HsCB2 of CP55,940 (2.5, 0.98, 0.92) and WIN55,212-2 (16.7, 2.4, 3.7) differed between HsCB1 and RnCB1 and between HsCB1 and HsCB2. SR141716A differed between HsCB1 and RnCB1 (2.9 and 1.0 nM). Anandamide at HsCB1, RnCB1 and HsCB2 (239.2, 87.7, 439.5) fell short of statistical differences due to heterogeneity. We consider these Kd and Ki values to be the most valid estimates in the literature. Sensitivity analyses did not support the numerical validity of cannabidiol, cannabinol, 2-arachidonoyl glycerol and all ligands at RnCB2. Aggregate rank order analysis of CB1 distribution in the brain (pooled from 119 autoradiographic, immunohistochemical and in situ hybridization studies) showed denser HsCB1 expression in cognitive regions (cerebral cortex) compared to RnCB1, which was relatively richer in movement-associated areas (cerebellum, caudate-putamen). Implications of interspecies differences are discussed. PMID:17641667

  9. Asymmetric viability of reciprocal-cross hybrids between crested and marbled newts (Triturus cristatus and T. Marmoratus).

    PubMed

    Arntzen, Jan W; Jehle, Robert; Bardakci, Fevzi; Burke, Terry; Wallis, Graham P

    2009-05-01

    Hybridization between divergent lineages often results in reduced hybrid viability. Here we report findings from a series of independent molecular analyses over several seasons on four life stages of F1 hybrids between the newts Triturus cristatus and T. marmoratus. These two species form a bimodal hybrid zone of broad overlap in France, with F1 hybrids making up about 4% of the adult population. We demonstrate strong asymmetry in the direction of the cross, with one class (cristatus-mothered) making up about 90% of F1 hybrids. By analyzing embryos and hatchlings, we show that this asymmetry is not due to prezygotic effects, as both classes of hybrid embryos are present at similar frequencies, implicating differential selection on the two hybrid classes after hatching. Adult F1 hybrids show a weak Haldane effect overall, with a 72% excess of females. The rarer marmoratus-mothered class, however, consists entirely of males. The absence of females from this class of adult F1 hybrids is best explained by an incompatibility between the cristatus X chromosome and marmoratus cytoplasm. It is thus important to distinguish the two classes of reciprocal-cross hybrids before making general statements about whether Haldane's rule is observed.

  10. Estimated emissions of chlorofluorocarbons, hydrochlorofluorocarbons, and hydrofluorocarbons based on an interspecies correlation method in the Pearl River Delta region, China.

    PubMed

    Wu, Jing; Fang, Xuekun; Martin, Jonathan W; Zhai, Zihan; Su, Shenshen; Hu, Xia; Han, Jiarui; Lu, Sihua; Wang, Chen; Zhang, Jianbo; Hu, Jianxin

    2014-02-01

    Although many studies have been conducted in recent years on the emissions of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs) at the large regional (such as East Asia) and national scales, relatively few studies have been conducted for cities or metropolitan areas. In this study, 192 air samples were collected in the Pearl River Delta (PRD) region of China in November 2010. The atmospheric mixing ratios of six halocarbons were analyzed, including trichlorofluoromethane (CFC-11, CCl3F), dichlorodifluoromethane (CFC-12, CCl2F2), monochlorodifluoromethane (HCFC-22, CHClF2), 1,1-dichloro-1-fluoroethane (HCFC-141b, CH3CCl2F), 1-dichloro-1,1-fluoroethane (HCFC-142b, CH3CClF2), and 1,1,1,2-tetrafluoroethane (HFC-134a, CH2FCF3), and their emissions were estimated based on an interspecies correlation method using HCFC-22 as the reference species. The results showed no significant change in the regional concentration and emission of CFC in the past 10years, suggesting that the continuous regional emission of CFC has had no significant effect on the CFC regional concentration in the PRD region. Concentrations and emissions of HCFCs and HFCs are significantly higher compared to previous research in the PRD region (P<0.05). The largest emission was for HCFC-22, most likely due to its substitution for CFC-12 in the industrial and commercial refrigeration subsector, and the rapid development of the room air-conditioner and extruded polystyrene subsectors. The PRD's ODP-weighted emissions of the target HCFCs provided 9% (7-12%) of the national emissions for the corresponding species. The PRD's GWP-weighted emissions of the target HCFCs and HFC-134a account for 10% (7-12%) and 8% (7-9%), respectively, of the national emissions for the corresponding species, and thus are important contributions to China's total emissions. © 2013 Elsevier B.V. All rights reserved.

  11. Transcriptional Response to Lactic Acid Stress in the Hybrid Yeast Zygosaccharomyces parabailii.

    PubMed

    Ortiz-Merino, Raúl A; Kuanyshev, Nurzhan; Byrne, Kevin P; Varela, Javier A; Morrissey, John P; Porro, Danilo; Wolfe, Kenneth H; Branduardi, Paola

    2018-03-01

    Lactic acid has a wide range of applications starting from its undissociated form, and its production using cell factories requires stress-tolerant microbial hosts. The interspecies hybrid yeast Zygosaccharomyces parabailii has great potential to be exploited as a novel host for lactic acid production, due to high organic acid tolerance at low pH and a fermentative metabolism with a high growth rate. Here we used mRNA sequencing (RNA-seq) to analyze Z. parabailii 's transcriptional response to lactic acid added exogenously, and we explore the biological mechanisms involved in tolerance. Z. parabailii contains two homeologous copies of most genes. Under lactic acid stress, the two genes in each homeolog pair tend to diverge in expression to a significantly greater extent than under control conditions, indicating that stress tolerance is facilitated by interactions between the two gene sets in the hybrid. Lactic acid induces downregulation of genes related to cell wall and plasma membrane functions, possibly altering the rate of diffusion of lactic acid into cells. Genes related to iron transport and redox processes were upregulated, suggesting an important role for respiratory functions and oxidative stress defense. We found differences in the expression profiles of genes putatively regulated by Haa1 and Aft1/Aft2, previously described as lactic acid responsive in Saccharomyces cerevisiae Furthermore, formate dehydrogenase ( FDH ) genes form a lactic acid-responsive gene family that has been specifically amplified in Z. parabailii in comparison to other closely related species. Our study provides a useful starting point for the engineering of Z. parabailii as a host for lactic acid production. IMPORTANCE Hybrid yeasts are important in biotechnology because of their tolerance to harsh industrial conditions. The molecular mechanisms of tolerance can be studied by analyzing differential gene expression under conditions of interest and relating gene expression patterns

  12. Spontaneous heterosis in larval life-history traits of hemiclonal frog hybrids

    PubMed Central

    Hotz, Hansjürg; Semlitsch, Raymond D.; Gutmann, Eva; Guex, Gaston-Denis; Beerli, Peter

    1999-01-01

    European water frog hybrids Rana esculenta (Rana ridibunda × Rana lessonae) reproduce hemiclonally, transmitting only their ridibunda genome to gametes. We compared fitness-related larval life-history traits of natural R. esculenta from Poland with those of the two sympatric parental species and of newly generated F1 hybrids. Compared with either parental species, F1 hybrid offspring had higher survival, higher early growth rates, a more advanced developmental stage by day 49, and earlier metamorphosis, but similar mass at metamorphosis. R. esculenta from natural lineages had trait values intermediate between those of F1 offspring and of the two parental species. The data support earlier observations on natural R. esculenta that had faster larval growth, earlier metamorphosis, and higher resistance to hypoxic conditions compared with either parental species. Observing larval heterosis in F1 hybrids in survival, growth rate, and time to metamorphosis, however, at an even higher degree than in hybrids from natural lineages, demonstrates that heterosis is spontaneous and results from hybridity per se rather than from subsequent interclonal selection; in natural lineages the effects of hybridity and of clonal history are confounded. This is compelling evidence for spontaneous heterosis in hybrid clonals. Results on hemiclonal fish hybrids (Poeciliopsis) showed no spontaneous heterosis; thus, our frog data are not applicable to all hybrid clonals. Our data do show, however, that heterosis is an important potential source for the extensively observed ecological success of hybrid clonals. We suggest that heterosis and interclonal selection together shape fitness of natural R. esculenta lineages. PMID:10051613

  13. Cortisol Release in Response to UVB Exposure in Xiphophorus Fish

    PubMed Central

    Contreras, Adam J.; Boswell, Mikki; Downs, Kevin P.; Pasquali, Amanda; Walter, Ronald B.

    2014-01-01

    Xiphophorus fishes are comprised of 26 known species. Interspecies hybridization between select species has been utilized to produce experimental models to study melanoma development. Xiphophorus melanoma induction protocols utilize ultraviolet light (UVB) to induce DNA damage and associated downstream tumorigenesis. However, the impact of induced stress caused by the UVB treatment of the experimental animals undergoing tumor induction protocols has not been assessed. Stress is an adaptive physiological response to excessive or unpredictable environmental stimuli. The stress response in fishes may be measured by assay of cortisol released into the water. Here, we present results from investigations of stress response during experimental treatment and UVB exposure in X. maculatus Jp 163 B, X. couchianus, and F1 interspecies hybrids produced from the mating X. maculatus Jp 163 B x X. couchianus. Overall, cortisol release rates for males and females after UVB exposure showed no statistical differences. At lower UVB doses (8 and 16 kJ/m2), X. couchianus exhibited 2 fold higher levels of DNA damage then either X. maculatus or the F1 hybrid. However, based on cortisol release rates, none of the fish types tested induced a primary stress response at the UVB lower doses (8 and 16 kJ/m2). In contrast, at a very high UVB dose (32 kJ/m2) both X. maculatus and the F1 hybrid showed a 5 fold increase in cortisol release rate. To determine the effect of pigmentation on UVB induced stress, wild type and albino X. hellerii were exposed to UVB (32 kJ/m2). Albino X. hellerii exhibited 3.7 fold increase in cortisol release while wild type X. hellerii did not exhibit a significant cortisol response to UVB. Overall, the data suggest the rather low UVB doses often employed in tumour induction protocols do not induce a primary stress response in Xiphophorus fishes. PMID:24625568

  14. Application of ISSR markers for verification of F₁ hybrids in mungbean (Vigna radiata).

    PubMed

    Khajudparn, P; Prajongjai, T; Poolsawat, O; Tantasawat, P A

    2012-09-17

    Mungbean improvement via hybridization requires the identification of true F(1) hybrids from controlled crosses before further generations of selfing/crossing and selection. We utilized inter-simple sequence repeat (ISSR) markers for identifying putative F(1) hybrids from six cross combinations whose morphological characteristics were very similar to those of their respective female parents and could not be visually discriminated from the self-pollinated progeny. Based on 10 ISSR primers, polymorphisms were found between female and male parents of all six cross combinations. The highest value of genetic differentiation (21.4%) was found between male and female parents of the SUT3 x M5-1 cross. These 10 ISSR primers gave 2.8-25.0% polymorphism between male and female parents, with a mean of 12.1%, and 0-13.0% polymorphism between F(1) hybrid and female parents, with a mean of 4.8%. F(1) hybrids of all six cross combinations could be differentiated from the self-pollinated progeny of their female parents by using only either ISSR 841 or 857 primers, together with the ISSR 835 primer. We conclude that ISSR markers are useful and efficient for identifying mungbean F(1) hybrids in controlled crosses from different genetic background.

  15. Studies of wolf x coyote hybridization via artificial insemination.

    PubMed

    Mech, L David; Asa, Cheryl S; Callahan, Margaret; Christensen, Bruce W; Smith, Fran; Young, Julie K

    2017-01-01

    Following the production of western gray wolf (Canis lupus) x western coyote (Canis latrans) hybrids via artificial insemination (AI), the present article documents that the hybrids survived in captivity for at least 4 years and successfully bred with each other. It further reports that backcrossing one of the hybrids to a male gray wolf by AI also resulted in the birth of live pups that have survived for at least 10 months. All male hybrids (F1 and F2) produced sperm by about 10 months of age, and sperm quality of the F1 males fell within the fertile range for domestic dogs, but sperm motility and morphology, in particular, were low in F2 males at 10 months but improved in samples taken at 22 months of age. These studies are relevant to a long-standing controversy about the identity of the red wolf (Canis rufus), the existence of a proposed new species (Canis lycaon) of gray wolf, and to the role of hybridization in mammalian evolution.

  16. Studies of wolf x coyote hybridization via artificial insemination

    PubMed Central

    2017-01-01

    Following the production of western gray wolf (Canis lupus) x western coyote (Canis latrans) hybrids via artificial insemination (AI), the present article documents that the hybrids survived in captivity for at least 4 years and successfully bred with each other. It further reports that backcrossing one of the hybrids to a male gray wolf by AI also resulted in the birth of live pups that have survived for at least 10 months. All male hybrids (F1 and F2) produced sperm by about 10 months of age, and sperm quality of the F1 males fell within the fertile range for domestic dogs, but sperm motility and morphology, in particular, were low in F2 males at 10 months but improved in samples taken at 22 months of age. These studies are relevant to a long-standing controversy about the identity of the red wolf (Canis rufus), the existence of a proposed new species (Canis lycaon) of gray wolf, and to the role of hybridization in mammalian evolution. PMID:28863171

  17. Studies of wolf x coyote hybridization via artificial insemination

    USGS Publications Warehouse

    Mech, L. David; Asa, Cheryl S.; Callahan, Margaret; Christensen, Bruce W.; Smith, Fran; Young, Julie K.

    2017-01-01

    Following the production of western gray wolf (Canis lupus) x western coyote (Canis latrans) hybrids via artificial insemination (AI), the present article documents that the hybrids survived in captivity for at least 4 years and successfully bred with each other. It further reports that backcrossing one of the hybrids to a male gray wolf by AI also resulted in the birth of live pups that have survived for at least 10 months. All male hybrids (F1 and F2) produced sperm by about 10 months of age, and sperm quality of the F1 males fell within the fertile range for domestic dogs, but sperm motility and morphology, in particular, were low in F2 males at 10 months but improved in samples taken at 22 months of age. These studies are relevant to a long-standing controversy about the identity of the red wolf (Canis rufus), the existence of a proposed new species (Canis lycaon) of gray wolf, and to the role of hybridization in mammalian evolution.

  18. INTER-SPECIES MODELS FOR ACUTE AQUATIC TOXICITY BASED ON MECHANISM OF ACTION

    EPA Science Inventory

    This presentation will provide interspecies QSARs for acute toxicity to 17 aquatic species, such as fish, snail, tadpole, hydrozoan, crustacean, insect larvae, and bacteria developed using 5,000 toxic effect results for approximately 2400 chemicals.

  19. A Functional Analysis on the Interspecies Interaction between Mouse LFA-1 and Human Intercellular Adhesion Molecule-1 at the Cell Level

    PubMed Central

    Núñez, David; Comas, Laura; Lanuza, Pilar M.; Sánchez-Martinez, Diego; Pérez-Hernández, Marta; Catalán, Elena; Domingo, María Pilar; Velázquez-Campoy, Adrián; Pardo, Julián; Gálvez, Eva M.

    2017-01-01

    The interaction between intercellular adhesion molecules (ICAM) and the integrin leukocyte function-associated antigen-1 (LFA-1) is crucial for the regulation of several physiological and pathophysiological processes like cell-mediated elimination of tumor or virus infected cells, cancer metastasis, or inflammatory and autoimmune processes. Using purified proteins it was reported a species restriction for the interaction of ICAM-1 and LFA-1, being mouse ICAM-1 able to interact with human LFA-1 but not human ICAM-1 with mouse LFA-1. However, in vivo results employing tumor cells transfected with human ICAM-1 suggest that functionally mouse LFA-1 can recognize human ICAM-1. In order to clarify the interspecies cross-reactivity of the ICAM-1/LFA-1 interaction, we have performed functional studies analyzing the ability of human soluble ICAM-1 and human/mouse LFA-1 derived peptides to inhibit cell aggregation and adhesion as well as cell-mediated cytotoxicity in both mouse and human systems. In parallel, the affinity of the interaction between mouse LFA-1-derived peptides and human ICAM-1 was determined by calorimetry assays. According to the results obtained, it seems that human ICAM-1 is able to interact with mouse LFA-1 on intact cells, which should be taking into account when using humanized mice and xenograft models for the study of immune-related processes. PMID:29312326

  20. A Functional Analysis on the Interspecies Interaction between Mouse LFA-1 and Human Intercellular Adhesion Molecule-1 at the Cell Level.

    PubMed

    Núñez, David; Comas, Laura; Lanuza, Pilar M; Sánchez-Martinez, Diego; Pérez-Hernández, Marta; Catalán, Elena; Domingo, María Pilar; Velázquez-Campoy, Adrián; Pardo, Julián; Gálvez, Eva M

    2017-01-01

    The interaction between intercellular adhesion molecules (ICAM) and the integrin leukocyte function-associated antigen-1 (LFA-1) is crucial for the regulation of several physiological and pathophysiological processes like cell-mediated elimination of tumor or virus infected cells, cancer metastasis, or inflammatory and autoimmune processes. Using purified proteins it was reported a species restriction for the interaction of ICAM-1 and LFA-1, being mouse ICAM-1 able to interact with human LFA-1 but not human ICAM-1 with mouse LFA-1. However, in vivo results employing tumor cells transfected with human ICAM-1 suggest that functionally mouse LFA-1 can recognize human ICAM-1. In order to clarify the interspecies cross-reactivity of the ICAM-1/LFA-1 interaction, we have performed functional studies analyzing the ability of human soluble ICAM-1 and human/mouse LFA-1 derived peptides to inhibit cell aggregation and adhesion as well as cell-mediated cytotoxicity in both mouse and human systems. In parallel, the affinity of the interaction between mouse LFA-1-derived peptides and human ICAM-1 was determined by calorimetry assays. According to the results obtained, it seems that human ICAM-1 is able to interact with mouse LFA-1 on intact cells, which should be taking into account when using humanized mice and xenograft models for the study of immune-related processes.

  1. ''1/f noise'' in music: Music from 1/f noise

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

    Voss, R.F.; Clarke, J.

    1978-01-01

    The spectral density of fluctuations in the audio power of many musical selections and of English speech varies approximately as 1/f (f is the frequency) down to a frequency of 5 x 10/sup -4/ Hz. This result implies that the audio-power fluctuations are correlated over all times in the same manner as ''1/f noise'' in electronic components. The frequency fluctuations of music also have a 1/f spectral density at frequencies down to the inverse of the length of the piece of music. The frequency fluctuations of English speech have a quite different behavior, with a single characteristic time of aboutmore » 0.1 s, the average length of a syllable. The observations on music suggest that 1/f noise is a good choice for stochastic composition. Compositions in which the frequency and duration of each note were determined by 1/f noise sources sounded pleasing. Those generated by white-noise sources sounded too random, while those generated by 1/f/sup 2/ noise sounded too correlated.« less

  2. Development of Species Sensitivity Distributions for Wildlife Using Interspecies Toxicity Correlation Models

    EPA Science Inventory

    Species sensitivity distributions (SSD) are cumulative distributions of chemical toxicity of multiple species and have had limited application in wildlife risk assessment because of relatively small datasets of wildlife toxicity values. Interspecies correlation estimation (ICE) m...

  3. PV-Diesel Hybrid SCADA Experiment Network Design

    NASA Technical Reports Server (NTRS)

    Kalu, Alex; Durand, S.; Emrich, Carol; Ventre, G.; Wilson, W.; Acosta, R.

    1999-01-01

    The essential features of an experimental network for renewable power system satellite based supervisory, control and data acquisition (SCADA) are communication links, controllers, diagnostic equipment and a hybrid power system. Required components for implementing the network consist of two satellite ground stations, to satellite modems, two 486 PCs, two telephone receivers, two telephone modems, two analog telephone lines, one digital telephone line, a hybrid-power system equipped with controller and a satellite spacecraft. In the technology verification experiment (TVE) conducted by Savannah State University and Florida Solar Energy Center, the renewable energy hybrid system is the Apex-1000 Mini-Hybrid which is equipped with NGC3188 for user interface and remote control and the NGC2010 for monitoring and basic control tasks. This power system is connected to a satellite modem via a smart interface, RS232. Commands are sent to the power system control unit through a control PC designed as PC1. PC1 is thus connected to a satellite model through RS232. A second PC, designated PC2, the diagnostic PC is connected to both satellite modems via separate analog telephone lines for checking modems'health. PC2 is also connected to PC1 via a telephone line. Due to the unavailability of a second ground station for the ACTS, one ground station is used to serve both the sending and receiving functions in this experiment. Signal is sent from the control PC to the Hybrid system at a frequency f(sub 1), different from f(sub 2), the signal from the hybrid system to the control PC. f(sub l) and f(sub 2) are sufficiently separated to avoid interference.

  4. Assessing hybrid sterility in Oryza glaberrima x O. sativa hybrid progenies by PCR marker analysis and crossing with wide compatibility varieties.

    PubMed

    Heuer, Sigrid; Miézan, Kouamé M

    2003-09-01

    Interspecific crossing of the African indigenous rice Oryza glaberrima with Oryza sativa cultivars is hindered by crossing barriers causing 100% spikelet sterility in F(1) hybrids. Since hybrids are partially female fertile, fertility can be restored by back crossing (BC) to a recurrent male parent. Distinct genetic models on spikelet sterility have been developed predicting, e.g., the existence of a gamete eliminator and/or a pollen killer. Linkage of sterility to the waxy starch synthase gene and the chromogen gene C, both located on chromosome 6, have been demonstrated. We selected a segregating BC(2)F(3) population of semi-sterile O. glaberrima x O. sativa indica hybrid progenies for analyses with PCR markers located at the respective chromosome-6 region. These analyses revealed that semi-sterile plants were heterozygous for a marker (OSR25) located in the waxy promoter, whereas fertile progenies were homozygous for the O. glaberrima allele. Adjacent markers showed no linkage to spikelet sterility. Semi-sterility of hybrid progenies was maintained at least until the F(4) progeny generation, suggesting the existence of a pollen killer in this plant material. Monitoring of reproductive plant development showed that spikelet sterility was at least partially due to an arrest of pollen development at the microspore stage. In order to address the question whether genes responsible for F(1) sterility in intraspecific hybrids ( O. sativa indica x japonica) also cause spikelet sterility in interspecific hybrids, crossings with wide compatibility varieties (WCV) were performed. WCV accessions possess "neutral" S-loci ( S(n)) improving fertility in intraspecific hybrids. This experiment showed that the tested S(n)-loci had no fertility restoring effect in F(1) interspecific hybrids. Pollen development was completely arrested at the microspore stage and grains were never obtained after selfing. This suggests that distinct or additional S-loci are responsible for sterility

  5. Growth, morphology, and developmental instability of rainbow trout, Yellowstone cutthroat trout, and four hybrid generations

    USGS Publications Warehouse

    Ostberg, C.O.; Duda, J.J.; Graham, J.H.; Zhang, S.; Haywood, K. P.; Miller, B.; Lerud, T.L.

    2011-01-01

    Hybridization of cutthroat trout Oncorhynchus clarkii with nonindigenous rainbow trout O. mykiss contributes to the decline of cutthroat trout subspecies throughout their native range. Introgression by rainbow trout can swamp the gene pools of cutthroat trout populations, especially if there is little selection against hybrids. We used rainbow trout, Yellowstone cutthroat trout O. clarkii bouvieri, and rainbow trout × Yellowstone cutthroat trout F1 hybrids as parents to construct seven different line crosses: F1 hybrids (both reciprocal crosses), F2 hybrids, first-generation backcrosses (both rainbow trout and Yellowstone cutthroat trout), and both parental taxa. We compared growth, morphology, and developmental instability among these seven crosses reared at two different temperatures. Growth was related to the proportion of rainbow trout genome present within the crosses. Meristic traits were influenced by maternal, additive, dominant, overdominant, and (probably) epistatic genetic effects. Developmental stability, however, was not disturbed in F1 hybrids, F2 hybrids, or backcrosses. Backcrosses were morphologically similar to their recurrent parent. The lack of developmental instability in hybrids suggests that there are few genetic incompatibilities preventing introgression. Our findings suggest that hybrids are not equal: that is, growth, development, character traits, and morphology differ depending on the genomic contribution from each parental species as well as the hybrid generation.

  6. Mechanistic basis of infertility of mouse intersubspecific hybrids

    PubMed Central

    Bhattacharyya, Tanmoy; Gregorova, Sona; Mihola, Ondrej; Anger, Martin; Sebestova, Jaroslava; Denny, Paul; Simecek, Petr; Forejt, Jiri

    2013-01-01

    According to the Dobzhansky–Muller model, hybrid sterility is a consequence of the independent evolution of related taxa resulting in incompatible genomic interactions of their hybrids. The model implies that the incompatibilities evolve randomly, unless a particular gene or nongenic sequence diverges much faster than the rest of the genome. Here we propose that asynapsis of heterospecific chromosomes in meiotic prophase provides a recurrently evolving trigger for the meiotic arrest of interspecific F1 hybrids. We observed extensive asynapsis of chromosomes and disturbance of the sex body in >95% of pachynemas of Mus m. musculus × Mus m. domesticus sterile F1 males. Asynapsis was not preceded by a failure of double-strand break induction, and the rate of meiotic crossing over was not affected in synapsed chromosomes. DNA double-strand break repair was delayed or failed in unsynapsed autosomes, and misexpression of chromosome X and chromosome Y genes was detected in single pachynemas and by genome-wide expression profiling. Oocytes of F1 hybrid females showed the same kind of synaptic problems but with the incidence reduced to half. Most of the oocytes with pachytene asynapsis were eliminated before birth. We propose the heterospecific pairing of homologous chromosomes as a preexisting condition of asynapsis in interspecific hybrids. The asynapsis may represent a universal mechanistic basis of F1 hybrid sterility manifested by pachytene arrest. It is tempting to speculate that a fast-evolving subset of the noncoding genomic sequence important for chromosome pairing and synapsis may be the culprit. PMID:23329330

  7. Mechanistic basis of infertility of mouse intersubspecific hybrids.

    PubMed

    Bhattacharyya, Tanmoy; Gregorova, Sona; Mihola, Ondrej; Anger, Martin; Sebestova, Jaroslava; Denny, Paul; Simecek, Petr; Forejt, Jiri

    2013-02-05

    According to the Dobzhansky-Muller model, hybrid sterility is a consequence of the independent evolution of related taxa resulting in incompatible genomic interactions of their hybrids. The model implies that the incompatibilities evolve randomly, unless a particular gene or nongenic sequence diverges much faster than the rest of the genome. Here we propose that asynapsis of heterospecific chromosomes in meiotic prophase provides a recurrently evolving trigger for the meiotic arrest of interspecific F1 hybrids. We observed extensive asynapsis of chromosomes and disturbance of the sex body in >95% of pachynemas of Mus m. musculus × Mus m. domesticus sterile F1 males. Asynapsis was not preceded by a failure of double-strand break induction, and the rate of meiotic crossing over was not affected in synapsed chromosomes. DNA double-strand break repair was delayed or failed in unsynapsed autosomes, and misexpression of chromosome X and chromosome Y genes was detected in single pachynemas and by genome-wide expression profiling. Oocytes of F1 hybrid females showed the same kind of synaptic problems but with the incidence reduced to half. Most of the oocytes with pachytene asynapsis were eliminated before birth. We propose the heterospecific pairing of homologous chromosomes as a preexisting condition of asynapsis in interspecific hybrids. The asynapsis may represent a universal mechanistic basis of F1 hybrid sterility manifested by pachytene arrest. It is tempting to speculate that a fast-evolving subset of the noncoding genomic sequence important for chromosome pairing and synapsis may be the culprit.

  8. Description and identification of American Black Duck, Mallard, and hybrid wing plumage

    USGS Publications Warehouse

    Kirby, R.E.; Reed, A.; Dupuis, P.; Obrecht, H.H.; Quist, W.J.

    2000-01-01

    We developed a key to identify wings of hybrids between American Black Ducks (Anas rubripes) and Mallards (A. platyrhynchos). Material for analysis included review of historical descriptions dating from the late 1700's, older museum collections in Europe and North America, wings collected from hunters in North America and Great Britain, birds banded in Canada and the United States, and a flock of propagated hybrids. All first filial generation (F1) American Black Duck x Mallard hybrids were identified correctly with the key. A lower proportion of other hybrid cohorts (i.e., backcrosses of F1, to parental forms (P1), and second and third filial generations (F2, F3, etc.) were identified. We successfully identified a larger portion of male than female hybrids for all hybrid progeny cohorts examined except F1. The new key identified 2.37 times more hybrids in the 1977 U.S. Fish and Wildlife Service Parts Collection Survey (annual determination of the species, age, and sex composition of the waterfowl harvest using detached wings contributed by hunters) than were identified by standard techniques. The proportion of American Black Duck x Mallard hybrids to the American Black Duck parental population (the ratio: hybrids/[hybrids + American Black Ducks]) may therefore be closer to 0.132 than 0.056, the historically reported value. The hybrid key is suggested for use from North Carolina north in the Atlantic Flyway and Arkansas and Tennessee north in the Mississippi Flyway (areas where other members of the Mallard group will not confound assessment). We provide suggestions for further research that would assist identification of wings in parts collection surveys and permit estimation of the proportional representation of Mallard genes in the American Black Duck gene pool.

  9. Description and identification of American Black Duck, Mallard, and hybrid wing plumage

    USGS Publications Warehouse

    Kirby, Ronald E.; Reed, Austin; Dupuis, Pierre; Obrecht, Holliday H.; Quist, Walter J.

    2000-01-01

    We developed a key to identify wings of hybrids between American Black Ducks (Anas rubripes) and Mallards (A. platyrhynchos). Material for analysis included review of historical descriptions dating from the late 1700's, older museum collections in Europe and North America, wings collected from hunters in North America and Great Britain, birds banded in Canada and the United States, and a flock of propagated hybrids. All first filial generation (F1) American Black Duck - Mallard hybrids were identified correctly with the key. A lower proportion of other hybrid cohorts (i.e., backcrosses of F1 to parental forms (P1), and second and third filial generations (F2, F3, etc.) were identified. We successfully identified a larger portion of male than female hybrids for all hybrid progeny cohorts examined except F1. The new key identified 2.37 times more hybrids in the 1977 U.S. Fish and Wildlife Service Parts Collection Survey (annual determination of the species, age, and sex composition of the waterfowl harvest using detached wings contributed by hunters) than were identified by standard techniques. The proportion of American Black Duck - Mallard hybrids to the American Black Duck parental population (the ratio: hybrids/[hybrids + American Black Ducks]) may therefore be closer to 0.132 than 0.056, the historically reported value. The hybrid key is suggested for use from North Carolina north in the Atlantic Flyway and Arkansas and Tennessee north in the Mississippi Flyway (areas where other members of the Mallard group will not confound assessment). We provide suggestions for further research that would assist identification of wings in parts collection surveys and permit estimation of the proportional representation of Mallard genes in the American Black Duck gene pool.

  10. The existence of fertile hybrids of closely related model earthworm species, Eisenia andrei and E. fetida.

    PubMed

    Plytycz, Barbara; Bigaj, Janusz; Osikowski, Artur; Hofman, Sebastian; Falniowski, Andrzej; Panz, Tomasz; Grzmil, Pawel; Vandenbulcke, Franck

    2018-01-01

    Lumbricid earthworms Eisenia andrei (Ea) and E. fetida (Ef) are simultaneous hermaphrodites with reciprocal insemination capable of self-fertilization while the existence of hybridization of these two species was still debatable. During the present investigation fertile hybrids of Ea and Ef were detected. Virgin specimens of Ea and Ef were laboratory crossed (Ea+Ef) and their progeny was doubly identified. 1 -identified by species-specific maternally derived haploid mitochondrial DNA sequences of the COI gene being either 'a' for worms hatched from Ea ova or 'f' for worms hatched from Ef ova. 2 -identified by the diploid maternal/paternal nuclear DNA sequences of 28s rRNA gene being either 'AA' for Ea, 'FF' for Ef, or AF/FA for their hybrids derived either from the 'aA' or 'fF' ova, respectively. Among offspring of Ea+Ef pairs in F1 generation there were mainly aAA and fFF earthworms resulted from the facilitated self-fertilization and some aAF hybrids from aA ova but none fFA hybrids from fF ova. In F2 generation resulting from aAF hybrids mated with aAA a new generations of aAA and aAF hybrids were noticed, while aAF hybrids mated with fFF gave fFF and both aAF and fFA hybrids. Hybrids intercrossed together produced plenty of cocoons but no hatchlings independently whether aAF+aAF or aAF+fFA were mated. These results indicated that Ea and Ef species, easy to maintain in laboratory and commonly used as convenient models in biomedicine and ecotoxicology, may also serve in studies on molecular basis of interspecific barriers and mechanisms of introgression and speciation. Hypothetically, their asymmetrical hybridization can be modified by some external factors.

  11. Augmenting Species Diversity in Water Quality Criteria Derivation using Interspecies Correlation Models

    EPA Science Inventory

    The specific requirements for taxa diversity of the 1985 guidelines have limited the number of ambient water quality criteria (AWQC) developed for aquatic life protection. The EPA developed the Web-based Interspecies Correlation Estimation (Web-ICE) tool to allow extrapolation of...

  12. Demonstration of the Web-based Interspecies Correlation Estimation (Web-ICE) modeling application

    EPA Science Inventory

    The Web-based Interspecies Correlation Estimation (Web-ICE) modeling application is available to the risk assessment community through a user-friendly internet platform (http://epa.gov/ceampubl/fchain/webice/). ICE models are log-linear least square regressions that predict acute...

  13. Interspecies hormonal control of host root morphology by parasitic plants

    PubMed Central

    Melnyk, Charles W.; Wakatake, Takanori; Zhang, Jing; Sakamoto, Yuki; Kiba, Takatoshi; Yoshida, Satoko; Matsunaga, Sachihiro; Sakakibara, Hitoshi

    2017-01-01

    Parasitic plants share a common anatomical feature, the haustorium. Haustoria enable both infection and nutrient transfer, which often leads to growth penalties for host plants and yield reduction in crop species. Haustoria also reciprocally transfer substances, such as RNA and proteins, from parasite to host, but the biological relevance for such movement remains unknown. Here, we studied such interspecies transport by using the hemiparasitic plant Phtheirospermum japonicum during infection of Arabidopsis thaliana. Tracer experiments revealed a rapid and efficient transfer of carboxyfluorescein diacetate (CFDA) from host to parasite upon formation of vascular connections. In addition, Phtheirospermum induced hypertrophy in host roots at the site of infection, a form of enhanced secondary growth that is commonly observed during various parasitic plant–host interactions. The plant hormone cytokinin is important for secondary growth, and we observed increases in cytokinin and its response during infection in both host and parasite. Phtheirospermum-induced host hypertrophy required cytokinin signaling genes (AHK3,4) but not cytokinin biosynthesis genes (IPT1,3,5,7) in the host. Furthermore, expression of a cytokinin-degrading enzyme in Phtheirospermum prevented host hypertrophy. Wild-type hosts with hypertrophy were smaller than ahk3,4 mutant hosts resistant to hypertrophy, suggesting hypertrophy improves the efficiency of parasitism. Taken together, these results demonstrate that the interspecies movement of a parasite-derived hormone modified both host root morphology and fitness. Several microbial and animal plant pathogens use cytokinins during infections, highlighting the central role of this growth hormone during the establishment of plant diseases and revealing a common strategy for parasite infections of plants. PMID:28461500

  14. Interspecies hormonal control of host root morphology by parasitic plants.

    PubMed

    Spallek, Thomas; Melnyk, Charles W; Wakatake, Takanori; Zhang, Jing; Sakamoto, Yuki; Kiba, Takatoshi; Yoshida, Satoko; Matsunaga, Sachihiro; Sakakibara, Hitoshi; Shirasu, Ken

    2017-05-16

    Parasitic plants share a common anatomical feature, the haustorium. Haustoria enable both infection and nutrient transfer, which often leads to growth penalties for host plants and yield reduction in crop species. Haustoria also reciprocally transfer substances, such as RNA and proteins, from parasite to host, but the biological relevance for such movement remains unknown. Here, we studied such interspecies transport by using the hemiparasitic plant Phtheirospermum japonicum during infection of Arabidopsis thaliana Tracer experiments revealed a rapid and efficient transfer of carboxyfluorescein diacetate (CFDA) from host to parasite upon formation of vascular connections. In addition, Phtheirospermum induced hypertrophy in host roots at the site of infection, a form of enhanced secondary growth that is commonly observed during various parasitic plant-host interactions. The plant hormone cytokinin is important for secondary growth, and we observed increases in cytokinin and its response during infection in both host and parasite. Phtheirospermum -induced host hypertrophy required cytokinin signaling genes ( AHK3,4 ) but not cytokinin biosynthesis genes ( IPT1,3,5,7) in the host. Furthermore, expression of a cytokinin-degrading enzyme in Phtheirospermum prevented host hypertrophy. Wild-type hosts with hypertrophy were smaller than ahk3,4 mutant hosts resistant to hypertrophy, suggesting hypertrophy improves the efficiency of parasitism. Taken together, these results demonstrate that the interspecies movement of a parasite-derived hormone modified both host root morphology and fitness. Several microbial and animal plant pathogens use cytokinins during infections, highlighting the central role of this growth hormone during the establishment of plant diseases and revealing a common strategy for parasite infections of plants.

  15. Multi-technique investigation of the binary fraction of A-F type candidate hybrid variable stars discovered by Kepler

    NASA Astrophysics Data System (ADS)

    Lampens, P.; Frémat, Y.; Vermeylen, L.; Sódor, Á.; Skarka, M.; De Cat, P.; Bognár, Zs.; De Nutte, R.; Dumortier, L.; Escorza, A.; Oomen, G. M.; Van de Steene, G.; Kamath, D.; Laverick, M.; Samadi, A.; Triana, S.; Lehmann, H.

    2018-02-01

    our sample of candidate hybrid stars. Based on observations obtained with the Hermes spectrograph, which is supported by the Research Foundation - Flanders (FWO), Belgium, the Research Council of KU Leuven, Belgium, the Fonds National de la Recherche Scientifique (F.R.S.-FNRS), Belgium, the Royal Observatory of Belgium, the Observatoire de Genève, Switzerland, and the Thüringer Landessternwarte Tautenburg, Germany. Tables 2 and 3 are only, and Tables C.1-C.3 are also, available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A17

  16. Applying support vector machine on hybrid fNIRS/EEG signal to classify driver's conditions (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Nguyen, Thien; Ahn, Sangtae; Jang, Hyojung; Jun, Sung C.; Kim, Jae G.

    2016-03-01

    Driver's condition plays a critical role in driving safety. The fact that about 20 percent of automobile accidents occurred due to driver fatigue leads to a demand for developing a method to monitor driver's status. In this study, we acquired brain signals such as oxy- and deoxyhemoglobin and neuronal electrical activity by a hybrid fNIRS/EEG system. Experiments were conducted with 11 subjects under two conditions: Normal condition, when subjects had enough sleep, and sleep deprivation condition, when subject did not sleep previous night. During experiment, subject performed a driving task with a car simulation system for 30 minutes. After experiment, oxy-hemoglobin and deoxy-hemoglobin changes were derived from fNIRS data, while beta and alpha band relative power were calculated from EEG data. Decrement of oxy-hemoglobin, beta band power, and increment of alpha band power were found in sleep deprivation condition compare to normal condition. These features were then applied to classify two conditions by Fisher's linear discriminant analysis (FLDA). The ratio of alpha-beta relative power showed classification accuracy with a range between 62% and 99% depending on a subject. However, utilization of both EEG and fNIRS features increased accuracy in the range between 68% and 100%. The highest increase of accuracy is from 63% using EEG to 99% using both EEG and fNIRS features. In conclusion, the enhancement of classification accuracy is shown by adding a feature from fNIRS to the feature from EEG using FLDA which provides the need of developing a hybrid fNIRS/EEG system.

  17. Species and interspecies radioimmunoassays for rat type C virus p30: interviral comparisons and assay of human tumor extracts

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

    Charman, H.P.; White, M.H.; Rahman, R.

    1976-01-01

    The major internal protein, p30, of rat type C virus (RaLV) was purified and utilized to establish intra- and interspecies radioimmunoassays. Three rat viruses were compared in homologous and heterologous intraspecies assays with no evidence of type specificity. The only heterologous viruses to give inhibition in these species assays were the feline (FeLV) and hamster (HaLV) type C viruses; these reactions were incomplete and required high virus concentrations. An interspecies assay using a goat antiserum prepared after sequentially immunizing with FeLV, RD 114, and woolly monkey virus p30's and labeled RaLV p30 was inhibited by all mammalian type C viruses,more » although preferentially by RaLV, FeLV, and HaLV. Thus, as in a previously reported assay developed with HaLV p30, rat, hamster, and cat p30's seem more closely related to each other than to mouse type C virus p30. High levels of specific antigen were found in all cell lines producing rat virus, whereas embryonic tissues from several rat strains and cell lines considered virus-free based on other tests were negative for p30. Rats bearing tumors containing Moloney murine sarcoma virus (RaLV) did not contain free circulating antibody to RaLV p30. Fifty-one human tumor extracts (including two tumor cell lines) were tested for activity in the RaLV species and 47 in the interspecies assays after Sephadex gel filtration and pooling of material in the 15,000- to 40,000-molecular-weight range. At a sensitivity level of 7 ng/ml (0.7 ng/assay) in the interspecies assay, all human tissues, with one exception, were negative. The one positive result is considered nonspecific based on proteolysis of the labeled antigen. Input tissue protein of the purified tumor extracts averaged 1.9 mg/ml with a range of less than 0.025 to 22 mg/ml. Tissues from NIH Swiss mice processed in the same manner were positive in the interspecies assay but negative in the intraspecies RaLV assay. (auth)« less

  18. The existence of fertile hybrids of closely related model earthworm species, Eisenia andrei and E. fetida

    PubMed Central

    Bigaj, Janusz; Osikowski, Artur; Hofman, Sebastian; Falniowski, Andrzej; Panz, Tomasz; Grzmil, Pawel; Vandenbulcke, Franck

    2018-01-01

    Lumbricid earthworms Eisenia andrei (Ea) and E. fetida (Ef) are simultaneous hermaphrodites with reciprocal insemination capable of self-fertilization while the existence of hybridization of these two species was still debatable. During the present investigation fertile hybrids of Ea and Ef were detected. Virgin specimens of Ea and Ef were laboratory crossed (Ea+Ef) and their progeny was doubly identified. 1 –identified by species-specific maternally derived haploid mitochondrial DNA sequences of the COI gene being either ‘a’ for worms hatched from Ea ova or ‘f’ for worms hatched from Ef ova. 2 –identified by the diploid maternal/paternal nuclear DNA sequences of 28s rRNA gene being either ‘AA’ for Ea, ‘FF’ for Ef, or AF/FA for their hybrids derived either from the ‘aA’ or ‘fF’ ova, respectively. Among offspring of Ea+Ef pairs in F1 generation there were mainly aAA and fFF earthworms resulted from the facilitated self-fertilization and some aAF hybrids from aA ova but none fFA hybrids from fF ova. In F2 generation resulting from aAF hybrids mated with aAA a new generations of aAA and aAF hybrids were noticed, while aAF hybrids mated with fFF gave fFF and both aAF and fFA hybrids. Hybrids intercrossed together produced plenty of cocoons but no hatchlings independently whether aAF+aAF or aAF+fFA were mated. These results indicated that Ea and Ef species, easy to maintain in laboratory and commonly used as convenient models in biomedicine and ecotoxicology, may also serve in studies on molecular basis of interspecific barriers and mechanisms of introgression and speciation. Hypothetically, their asymmetrical hybridization can be modified by some external factors. PMID:29370238

  19. Hybridization increases invasive knotweed success

    PubMed Central

    Parepa, Madalin; Fischer, Markus; Krebs, Christine; Bossdorf, Oliver

    2014-01-01

    Hybridization is one of the fundamental mechanisms by which rapid evolution can occur in exotic species. If hybrids show increased vigour, this could significantly contribute to invasion success. Here, we compared the success of the two invasive knotweeds, Fallopia japonica and F. sachalinensis, and their hybrid, F. × bohemica, in competing against experimental communities of native plants. Using plant material from multiple clones of each taxon collected across a latitudinal gradient in Central Europe, we found that knotweed hybrids performed significantly better in competition with a native community and that they more strongly reduced the growth of the native plants. One of the parental species, F. sachalinensis, regenerated significantly less well from rhizomes, and this difference disappeared if activated carbon was added to the substrate, which suggests allelopathic inhibition of F. sachalinensis regeneration by native plants. We found substantial within-taxon variation in competitive success in all knotweed taxa, but variation was generally greatest in the hybrid. Interestingly, there was also significant variation within the genetically uniform F. japonica, possibly reflecting epigenetic differences. Our study shows that invasive knotweed hybrids are indeed more competitive than their parents and that hybridization increased the invasiveness of the exotic knotweed complex. PMID:24665343

  20. Genetic Components of Heterosis for Seedling Traits in an Elite Rice Hybrid Analyzed Using an Immortalized F2 Population.

    PubMed

    Zhu, Dan; Zhou, Gang; Xu, Caiguo; Zhang, Qifa

    2016-02-20

    Utilization of heterosis has greatly contributed to rice productivity in China and many Asian countries. Superior hybrids usually show heterosis at two stages: canopy development at vegetative stage and panicle development at reproductive stage resulting in heterosis in yield. Although the genetic basis of heterosis in rice has been extensively investigated, all the previous studies focused on yield traits at maturity stage. In this study, we analyzed the genetic basis of heterosis at seedling stage making use of an "immortalized F2" population composed of 105 hybrids produced by intercrossing recombinant inbred lines (RILs) from a cross between Zhenshan 97 and Minghui 63, the parents of Shanyou 63, which is an elite hybrid widely grown in China. Eight seedling traits, seedling height, tiller number, leaf number, root number, maximum root length, root dry weight, shoot dry weight and total dry weight, were investigated using hydroponic culture. We analyzed single-locus and digenic genetic effects at the whole genome level using an ultrahigh-density SNP bin map obtained by population re-sequencing. The analysis revealed large numbers of heterotic effects for seedling traits including dominance, overdominance and digenic dominance (epistasis) in both positive and negative directions. Overdominance effects were prevalent for all the traits, and digenic dominance effects also accounted for a large portion of the genetic effects. The results suggested that cumulative small advantages of the single-locus effects and two-locus interactions, most of which could not be detected statistically, could explain the genetic basis of seedling heterosis of the F1 hybrid. Copyright © 2016 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  1. Interspecies nuclear transfer using fibroblasts from leopard, tiger, and lion ear piece collected postmortem as donor cells and rabbit oocytes as recipients.

    PubMed

    Yelisetti, Uma Mahesh; Komjeti, Suman; Katari, Venu Charan; Sisinthy, Shivaji; Brahmasani, Sambasiva Rao

    2016-06-01

    Skin fibroblast cells were obtained from a small piece of an ear of leopard, lion, and tiger collected postmortem and attempts were made to synchronize the skin fibroblasts at G0/G1 of cell cycle using three different approaches. Efficiency of the approaches was tested following interspecies nuclear transfer with rabbit oocytes as recipient cytoplasm. Fluorescence-activated cell sorting revealed that the proportion of G0/G1 cells increased significantly (P < 0.05) when cells subjected to serum starvation, contact inhibition, and 3 mM sodium butyrate (NaBu) treatment when compared with cycling cells. However, 3 mM NaBu treatment caused alterations in cell morphology and increase in dead cells. Thus, interspecies nuclear transfer was carried out using fibroblast cells subjected to contact inhibition for 72 h, serum starvation for 48 h, and cells treated with 1.0 mM NaBu for 48 h. The fusion rates, the proportion of fused couplets that cleaved to two-cell and developed to blastocyst, were highest in all three species when the donor cells were treated with 1.0 mM NaBu for 48 h. But, the blastocyst percentage of interspecies nuclear embryos (5-6%) was significantly lower when compared with rabbit-rabbit nuclear transfer embryos (22.9%). In conclusion, fibroblast cells of leopard, lion, and tiger were successfully synchronized and used for the development of blastocysts using rabbit oocytes as recipient cytoplasm.

  2. Effects of Inversions on Within- and Between-Species Recombination and Divergence

    PubMed Central

    Stevison, Laurie S.; Hoehn, Kenneth B.; Noor, Mohamed A. F.

    2011-01-01

    Chromosomal inversions disrupt recombination in heterozygotes by both reducing crossing-over within inverted regions and increasing it elsewhere in the genome. The reduction of recombination in inverted regions facilitates the maintenance of hybridizing species, as outlined by various models of chromosomal speciation. We present a comprehensive comparison of the effects of inversions on recombination rates and on nucleotide divergence. Within an inversion differentiating Drosophila pseudoobscura and Drosophila persimilis, we detected one double recombinant among 9,739 progeny from F1 hybrids screened, consistent with published double-crossover frequencies observed within species. Despite similar rates of exchange within and between species, we found no sequence-based evidence of ongoing gene exchange between species within this inversion, but significant exchange was inferred within species. We also observed greater differentiation at regions near inversion breakpoints between species versus within species. Moreover, we observed strong “interchromosomal effect” (higher recombination in inversion heterozygotes between species) with up to 9-fold higher recombination rates along collinear segments of chromosome two in hybrids. Further, we observed that regions most susceptible to changes in recombination rates corresponded to regions with lower recombination rates in homokaryotypes. Finally, we showed that interspecies nucleotide divergence is lower in regions with greater increases in recombination rate, potentially resulting from greater interspecies exchange. Overall, we have identified several similarities and differences between inversions segregating within versus between species in their effects on recombination and divergence. We conclude that these differences are most likely due to lower frequency of heterokaryotypes and to fitness consequences from the accumulation of various incompatibilities between species. Additionally, we have identified possible

  3. Interspecies sexual behaviour between a male Japanese macaque and female sika deer.

    PubMed

    Pelé, Marie; Bonnefoy, Alexandre; Shimada, Masaki; Sueur, Cédric

    2017-04-01

    Interspecies sexual behaviour or 'reproductive interference' has been reported across a wide range of animal taxa. However, most of these occurrences were observed in phylogenetically close species and were mainly discussed in terms of their effect on fitness, hybridization and species survival. The few cases of heterospecific mating in distant species occurred between animals that were bred and maintained in captivity. Only one scientific study has reported this phenomenon, describing sexual harassment of king penguins by an Antarctic fur seal. This is the first article to report mating behaviour between a male Japanese macaque (Macaca fuscata yakui) and female sika deer (Cervus nippon yakushimae) on Yakushima Island, Japan. Although Japanese macaques are known to ride deer, this individual showed clearly sexual behaviour towards several female deer, some of which tried to escape whilst others accepted the mount. This male seems to belong to a group of peripheral males. Although this phenomenon may be explained as copulation learning, this is highly unlikely. The most realistic hypothesis would be that of mate deprivation, which states that males with limited access to females are more likely to display this behaviour. Whatever the cause for this event may be, the observation of highly unusual animal behaviour may be a key to understanding the evolution of heterospecific mating behaviour in the animal kingdom.

  4. Multilocus sequence analysis reveals the genetic diversity of European fruit tree phytoplasmas and supports the existence of inter-species recombination.

    PubMed

    Danet, Jean Luc; Balakishiyeva, Gulnara; Cimerman, Agnès; Sauvion, Nicolas; Marie-Jeanne, Véronique; Labonne, Gérard; Lavina, Amparo; Batlle, Assumpcio; Krizanac, Ivana; Skoric, Dijana; Ermacora, Paolo; Serçe, Cigdem Ulubas; Caglayan, Kadriye; Jarausch, Wolfgang; Foissac, Xavier

    2011-02-01

    The genetic diversity of three temperate fruit tree phytoplasmas 'Candidatus Phytoplasma prunorum', 'Ca. P. mali' and 'Ca. P. pyri' has been established by multilocus sequence analysis. Among the four genetic loci used, the genes imp and aceF distinguished 30 and 24 genotypes, respectively, and showed the highest variability. Percentage of substitution for imp ranged from 50 to 68 % according to species. Percentage of substitution varied between 9 and 12 % for aceF, whereas it was between 5 and 6 % for pnp and secY. In the case of 'Ca P. prunorum' the three most prevalent aceF genotypes were detected in both plants and insect vectors, confirming that the prevalent isolates are propagated by insects. The four isolates known to be hypo-virulent had the same aceF sequence, indicating a possible monophyletic origin. Haplotype network reconstructed by eBURST revealed that among the 34 haplotypes of 'Ca. P. prunorum', the four hypo-virulent isolates also grouped together in the same clade. Genotyping of some Spanish and Azerbaijanese 'Ca. P. pyri' isolates showed that they shared some alleles with 'Ca. P. prunorum', supporting for the first time to our knowledge, the existence of inter-species recombination between these two species.

  5. Multifaceted, cross-generational costs of hybridization in sibling Drosophila species.

    PubMed

    Myers, Erin M; Harwell, Tiffany I; Yale, Elizabeth L; Lamb, Abigail M; Frankino, W Anthony

    2013-01-01

    Maladaptive hybridization, as determined by the pattern and intensity of selection against hybrid individuals, is an important factor contributing to the evolution of prezygotic reproductive isolation. To identify the consequences of hybridization between Drosophila pseudoobscura and D. persimilis, we estimated multiple fitness components for F1 hybrids and backcross progeny and used these to compare the relative fitness of parental species and their hybrids across two generations. We document many sources of intrinsic (developmental) and extrinsic (ecological) selection that dramatically increase the fitness costs of hybridization beyond the well-documented F1 male sterility in this model system. Our results indicate that the cost of hybridization accrues over multiple generations and reinforcement in this system is driven by selection against hybridization above and beyond the cost of hybrid male sterility; we estimate a fitness loss of >95% relative to the parental species across two generations of hybridization. Our findings demonstrate the importance of estimating hybridization costs using multiple fitness measures from multiple generations in an ecologically relevant context; so doing can reveal intense postzygotic selection against hybridization and thus, an enhanced role for reinforcement in the evolution of populations and diversification of species.

  6. Intravenous infusion of PAF affects ovulation, fertilization and preimplantation embryonic development in NZB x NZW F1 hybrid mice.

    PubMed

    Sakellariou, Maria; Drakakis, Peter; Antonopoulou, Smaragdi; Anagnostou, Elli; Loutradis, Dimitris; Patargias, Theoxaris

    2008-03-01

    Platelet Activating Factor (PAF) is a bioactive phospholipid, which exhibits a variety of biological activities and plays a significant role in all aspects of reproduction. In this work, a single intravenous injection of various concentrations of PAF shortly after Human Chorionic Gonadotropin (HCG) administration as well as 24 and 48 h before HCG administration was studied in NZB x NZW F1 hybrid mice. Optimum results were observed when PAF was injected just after the administration of HCG. In this protocol, the concentrations of PAF exhibited bell-shaped response to every stage of development. Any concentration of PAF between 5.5 x 10(-11) and 5.5 x 10(-15)g/g b.w., caused an improved ovulation rate, an increased fertilization rate, an increased rate of cell cycle and an enhanced hatching blastocyst rate (P<0.05 for all stages). Injection of lyso-PAF had no effect in any stage. Our data show that the effect of PAF on early stages of embryo development in vitro is dependent on its way of administration, on the concentrations used as well as on the time PAF is injected.

  7. Sexual dimorphism in hybrids rats.

    PubMed

    Garcia-Falgueras, Alicia; Pinos, Helena; Fernández, Rosa; Collado, Paloma; Pasaro, Eduardo; Segovia, Santiago; Guillamon, Antonio

    2006-12-06

    Laboratory rat strains descend from Wistar rats as a consequence of artificial selection. Previously we reported that the medial posterior division of the bed nucleus of the stria terminalis (BSTMP) was sexually dimorphic in Wistar and Long-Evans strains while the medial anterior division (BSTMA) and the locus coeruleus (LC) only showed sex differences in the ancestor Wistar strain. The lateral posterior division (BSTLP) was isomorphic in both strains. The present work studies the number of neurons in the BSTMP, BSTMA, BSTLP and LC of male and female Wistar and Long-Evans rats (F(0)) and their hybrid F(1) and F(2) generations. The BSTMP is sexually dimorphic in the F(0), F(1) and F(2) generations while sex differences in the LC are only seen in F(0) Wistar rats but not in the F(0) Long-Evans or the F(1) and F(2) hybrid generations. Sex differences in the BSTMA are seen in F(0) Wistar but not in F(0) Long-Evans rats and completely disappear in the F(2) generations. The number of neurons in the LC of both males and females decreased in heterozygotic individuals (F(1)) but increased in homozygotic (F(2)). However, the number of neurons in the BSTMP changes significantly over the generations, although the ratio of neurons (female/male) is stable and unaffected in homo- or heterozygosis. Thus, the mechanism that regulates the neuronal female/male ratio would be different from the one that controls the number of neurons. The facts that sex differences in the BSTMP are not affected by homo- or heterozygosis and that they are seen in several mammalian orders suggest the existence of a "fixed" type of brain sex differences in the Mammalia Class.

  8. Predicting the impact of biocorona formation kinetics on interspecies extrapolations of nanoparticle biodistribution modeling.

    PubMed

    Sahneh, Faryad Darabi; Scoglio, Caterina M; Monteiro-Riviere, Nancy A; Riviere, Jim E

    2015-01-01

    To assess the impact of biocorona kinetics on expected tissue distribution of nanoparticles (NPs) across species. The potential fate of NPs in vivo is described through a simple and descriptive pharmacokinetic model using rate processes dependent upon basal metabolic rate coupled to dynamics of protein corona. Mismatch of time scales between interspecies allometric scaling and the kinetics of corona formation is potentially a fundamental issue with interspecies extrapolations of NP biodistribution. The impact of corona evolution on NP biodistribution across two species is maximal when corona transition half-life is close to the geometric mean of NP half-lives of the two species. While engineered NPs can successfully reach target cells in rodent models, the results may be different in humans due to the fact that the longer circulation time allows for further biocorona evolution.

  9. GACD: Integrated Software for Genetic Analysis in Clonal F1 and Double Cross Populations.

    PubMed

    Zhang, Luyan; Meng, Lei; Wu, Wencheng; Wang, Jiankang

    2015-01-01

    Clonal species are common among plants. Clonal F1 progenies are derived from the hybridization between 2 heterozygous clones. In self- and cross-pollinated species, double crosses can be made from 4 inbred lines. A clonal F1 population can be viewed as a double cross population when the linkage phase is determined. The software package GACD (Genetic Analysis of Clonal F1 and Double cross) is freely available public software, capable of building high-density linkage maps and mapping quantitative trait loci (QTL) in clonal F1 and double cross populations. Three functionalities are integrated in GACD version 1.0: binning of redundant markers (BIN); linkage map construction (CDM); and QTL mapping (CDQ). Output of BIN can be directly used as input of CDM. After adding the phenotypic data, the output of CDM can be used as input of CDQ. Thus, GACD acts as a pipeline for genetic analysis. GACD and example datasets are freely available from www.isbreeding.net. © The American Genetic Association. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Automated aural classification used for inter-species discrimination of cetaceans.

    PubMed

    Binder, Carolyn M; Hines, Paul C

    2014-04-01

    Passive acoustic methods are in widespread use to detect and classify cetacean species; however, passive acoustic systems often suffer from large false detection rates resulting from numerous transient sources. To reduce the acoustic analyst workload, automatic recognition methods may be implemented in a two-stage process. First, a general automatic detector is implemented that produces many detections to ensure cetacean presence is noted. Then an automatic classifier is used to significantly reduce the number of false detections and classify the cetacean species. This process requires development of a robust classifier capable of performing inter-species classification. Because human analysts can aurally discriminate species, an automated aural classifier that uses perceptual signal features was tested on a cetacean data set. The classifier successfully discriminated between four species of cetaceans-bowhead, humpback, North Atlantic right, and sperm whales-with 85% accuracy. It also performed well (100% accuracy) for discriminating sperm whale clicks from right whale gunshots. An accuracy of 92% and area under the receiver operating characteristic curve of 0.97 were obtained for the relatively challenging bowhead and humpback recognition case. These results demonstrated that the perceptual features employed by the aural classifier provided powerful discrimination cues for inter-species classification of cetaceans.

  11. Proteomic Analysis of Pachytene Spermatocytes of Sterile Hybrid Male Mice.

    PubMed

    Wang, Lu; Guo, Yueshuai; Liu, Wenjing; Zhao, Weidong; Song, Gendi; Zhou, Tao; Huang, Hefeng; Guo, Xuejiang; Sun, Fei

    2016-09-01

    Incompatibilities in interspecific hybrids, such as reduced hybrid fertility and lethality, are common features resulting from reproductive isolation that lead to speciation. Subspecies crosses of house mice produce offspring in which one sex is infertile or absent, yet the molecular mechanisms of hybrid sterility are poorly understood. In this study, we observed extensive asynapsis of chromosomes and disturbance of the sex body in pachytene spermatocytes of sterile F1 males (PWK/Ph female × C57BL/6J male). We report the high-confidence identification of 4005 proteins in the pachytene spermatocytes of fertile F1 males (PWK/Ph male × C57BL/6J female) and sterile F1 males (PWK/Ph female × C57BL/6J male), of which 215 were upregulated and 381 were downregulated. Bioinformatics analysis of the proteome led to the identification of 43 and 59 proteins known to be essential for male meiosis and spermatogenesis in mice, respectively. Characterization of the proteome of pachytene spermatocytes associated with hybrid male sterility provides an inventory of proteins that is useful for understanding meiosis and the mechanisms of hybrid male infertility. © 2016 by the Society for the Study of Reproduction, Inc.

  12. Genome-scale transcriptional analyses of first-generation interspecific sunflower hybrids reveals broad regulatory compatibility

    PubMed Central

    2013-01-01

    Background Interspecific hybridization creates individuals harboring diverged genomes. The interaction of these genomes can generate successful evolutionary novelty or disadvantageous genomic conflict. Annual sunflowers Helianthus annuus and H. petiolaris have a rich history of hybridization in natural populations. Although first-generation hybrids generally have low fertility, hybrid swarms that include later generation and fully fertile backcross plants have been identified, as well as at least three independently-originated stable hybrid taxa. We examine patterns of transcript accumulation in the earliest stages of hybridization of these species via analyses of transcriptome sequences from laboratory-derived F1 offspring of an inbred H. annuus cultivar and a wild H. petiolaris accession. Results While nearly 14% of the reference transcriptome showed significant accumulation differences between parental accessions, total F1 transcript levels showed little evidence of dominance, as midparent transcript levels were highly predictive of transcript accumulation in F1 plants. Allelic bias in F1 transcript accumulation was detected in 20% of transcripts containing sufficient polymorphism to distinguish parental alleles; however the magnitude of these biases were generally smaller than differences among parental accessions. Conclusions While analyses of allelic bias suggest that cis regulatory differences between H. annuus and H. petiolaris are common, their effect on transcript levels may be more subtle than trans-acting regulatory differences. Overall, these analyses found little evidence of regulatory incompatibility or dominance interactions between parental genomes within F1 hybrid individuals, although it is unclear whether this is a legacy or an enabler of introgression between species. PMID:23701699

  13. Monoterpene emissions from needles of hybrid larch F1 (Larix gmelinii var. japonica × Larix kaempferi) grown under elevated carbon dioxide and ozone

    NASA Astrophysics Data System (ADS)

    Mochizuki, Tomoki; Watanabe, Makoto; Koike, Takayoshi; Tani, Akira

    2017-01-01

    We measured monoterpene emissions from needles of hybrid larch F1 (Larix gmelinii var. japonica × Larix kaempferi) to evaluate the response of monoterpene emission rates and their composition to elevated CO2 (600 μmol mol-1) and O3 (60 nmol mol-1) conditions. The dominant monoterpenes were α-pinene and β-pinene. The emission rate of total monoterpenes significantly decreased under elevated CO2 conditions (P < 0.05). The ratio of carbon emission in the form of monoterpenes to photosynthetically fixed carbon also significantly decreased under elevated CO2 conditions. By contrast, elevated O3 did not significantly affect the emission rate of total monoterpenes. The ratios of α-pinene/β-pinene, limonene/β-pinene, and myrcene/β-pinene were all significantly decreased by O3 exposure (P < 0.05). High reactivity of α-pinene, limonene, and myrcene when combining with O3 may be able to mitigate oxidative damage inside the larch needles. No significant combined effects of elevated CO2 and O3 on individual or total monoterpene emissions were detected.

  14. Detection of Hearing Loss Using 2f2-f1 and 2f1-f2 Distortion-Product Otoacoustic Emissions

    ERIC Educational Resources Information Center

    Fitzgerald, Tracy S.; Prieve, Beth A.

    2005-01-01

    Although many distortion-product otoacoustic emissions (DPOAEs) may be measured in the ear canal in response to 2 pure tone stimuli, the majority of clinical studies have focused exclusively on the DPOAE at the frequency 2f1-f2. This study investigated another DPOAE, 2f2-f1, in an attempt to determine the following: (a) the optimal stimulus…

  15. A diversity study of Saccharomycopsis fibuligera in rice wine starter nuruk, reveals the evolutionary process associated with its interspecies hybrid.

    PubMed

    Farh, Mohamed El-Agamy; Cho, Yunjoo; Lim, Jae Yun; Seo, Jeong-Ah

    2017-05-01

    The amylolytic yeast Saccharomycopsis fibuligera is the predominant yeast in the starter product, nuruk, which is utilized for rice wine production in South Korea. Latest molecular studies explore a recently developed interspecific hybridization among stains of S. fibuligera with a unique genetic feature. However, the origin of the natural hybridization occurrence is still unclear. Thus, to respectively distinguish parental and hybrid strains, specific primer sets were applied on 141 yeast strains isolated from different nuruk samples fermented in different provinces. Sixty-seven strains were defined accordingly as parental species with genome A while 8 strains were defined as hybrid strains. Unexpectedly, another parental species with genome B could not be found among the strain pools yet. Furthermore, it was observed that hybrid strains are phenotypically different from A genome strains; asci containing tetrad ascospores were observed in A genome strains more frequent than in hybrid strains. Nevertheless, hybrid strains were slightly more thermotolerant than A genome strains. Interestingly, all hybrid strains were located only in Jeju province. Based on these sets of data, we speculated that the unique climate of Jeju province might play an evolutionary role in the interspecific hybridization between A genome strains, as well as the unculturable allopatric B genome strains.

  16. ESTIMATION OF AQUATIC SPECIES SENSITIVITY USING INTERSPECIES CORRELATION AND ACUTE TO CHRONIC TOXICITY MODELS

    EPA Science Inventory

    Abstract for presentation

    Estimation of aquatic species sensitivity using interspecies correlation and acute to chronic toxicity models

    Determining species sensitivity of aquatic organisms to contaminants is a critical component of criteria development and ecolog...

  17. Activation of Ftz-F1-Responsive Genes through Ftz/Ftz-F1 Dependent Enhancers

    PubMed Central

    Field, Amanda; Xiang, Jie; Anderson, W. Ray; Graham, Patricia; Pick, Leslie

    2016-01-01

    The orphan nuclear receptor Ftz-F1 is expressed in all somatic nuclei in Drosophila embryos, but mutations result in a pair-rule phenotype. This was explained by the interaction of Ftz-F1 with the homeodomain protein Ftz that is expressed in stripes in the primordia of segments missing in either ftz-f1 or ftz mutants. Ftz-F1 and Ftz were shown to physically interact and coordinately activate the expression of ftz itself and engrailed by synergistic binding to composite Ftz-F1/Ftz binding sites. However, attempts to identify additional target genes on the basis of Ftz-F1/ Ftz binding alone has met with only limited success. To discern rules for Ftz-F1 target site selection in vivo and to identify additional target genes, a microarray analysis was performed comparing wildtype and ftz-f1 mutant embryos. Ftz-F1-responsive genes most highly regulated included engrailed and nine additional genes expressed in patterns dependent on both ftz and ftz-f1. Candidate enhancers for these genes were identified by combining BDTNP Ftz ChIP-chip data with a computational search for Ftz-F1 binding sites. Of eight enhancer reporter genes tested in transgenic embryos, six generated expression patterns similar to the corresponding endogenous gene and expression was lost in ftz mutants. These studies identified a new set of Ftz-F1 targets, all of which are co-regulated by Ftz. Comparative analysis of enhancers containing Ftz/Ftz-F1 binding sites that were or were not bona fide targets in vivo suggested that GAF negatively regulates enhancers that contain Ftz/Ftz-F1 binding sites but are not actually utilized. These targets include other regulatory factors as well as genes involved directly in morphogenesis, providing insight into how pair-rule genes establish the body pattern. PMID:27723822

  18. Acute toxicity prediction to threatened and endangered species using Interspecies Correlation Estimation (ICE) models

    EPA Science Inventory

    Evaluating contaminant sensitivity of threatened and endangered (listed) species and protectiveness of chemical regulations often depends on toxicity data for commonly tested surrogate species. The U.S. EPA’s Internet application Web-ICE is a suite of Interspecies Correlati...

  19. Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice.

    PubMed

    McInnis, Christine M; Bonthuis, Paul J; Rissman, Emilie F; Park, Jin Ho

    2016-04-01

    The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrates steroid-independent male sexual behavior (identified as "maters"), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or "non-maters". A significant proportion of the BXB1 maters was sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior. Copyright

  20. Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice

    PubMed Central

    McInnis, Christine M.; Bonthuis, Paul J.; Rissman, Emilie F.; Park, Jin Ho

    2016-01-01

    The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrate steroid-independent male sexual behavior (identified as “maters”), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or “non-maters.” A significant proportion of the BXB1 maters were sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior

  1. Promoting Interspecies Electron Transfer with Biochar

    PubMed Central

    Chen, Shanshan; Rotaru, Amelia-Elena; Shrestha, Pravin Malla; Malvankar, Nikhil S.; Liu, Fanghua; Fan, Wei; Nevin, Kelly P.; Lovley, Derek R.

    2014-01-01

    Biochar, a charcoal-like product of the incomplete combustion of organic materials, is an increasingly popular soil amendment designed to improve soil fertility. We investigated the possibility that biochar could promote direct interspecies electron transfer (DIET) in a manner similar to that previously reported for granular activated carbon (GAC). Although the biochars investigated were 1000 times less conductive than GAC, they stimulated DIET in co-cultures of Geobacter metallireducens with Geobacter sulfurreducens or Methanosarcina barkeri in which ethanol was the electron donor. Cells were attached to the biochar, yet not in close contact, suggesting that electrons were likely conducted through the biochar, rather than biological electrical connections. The finding that biochar can stimulate DIET may be an important consideration when amending soils with biochar and can help explain why biochar may enhance methane production from organic wastes under anaerobic conditions. PMID:24846283

  2. Analysis of Oxidative Stress and Wound-Inducible Dinor Isoprostanes F1 (Phytoprostanes F1) in Plants1

    PubMed Central

    Imbusch, Ruth; Mueller, Martin J.

    2000-01-01

    Isoprostanes F2 are arachidonate autoxidation products in mammals that have been shown to be induced during several human disorders associated with enhanced free-radical generation. Isoprostanes F2 represent not only extremely reliable markers of oxidative stress in vivo, but they also exert potent biological effects. Therefore, it has been postulated that isoprostanoids are mediators of oxidant injury in vivo. Higher plants, however, do not synthesize arachidonic acid or isoprostanes. Here we show that a series of isoprostane F2 analogs termed phytoprostanes F1 (previously dinor isoprostanes F1) are formed by an analogous pathway from α-linolenate in plants. High-performance liquid chromatography and gas chromatography-mass spectrometry methods using [18O]3phytoprostanes F1 as internal standard have been developed to quantify phytoprostanes F1. In fresh peppermint (Mentha piperita) leaves, phytoprostanes F1 were found in free form (76 ng/g of dry weight) and at about 150-fold higher levels esterified in lipids. It is notable that these levels of phytoprostanes F1 are more than two orders of magnitude higher than the basal levels of isoprostanes F2 in mammalian tissues. Furthermore, wounding, as well as butyl hydroperoxide or cupric acetate stress triggered a dramatic increase of free and esterified phytoprostanes F1. Thus phytoprostanes F1 may represent a sensitive measure of oxidative damage in plants similar to isoprostanes in mammals. However, one of the most exciting issues to be clarified is the possibility that linolenate-derived phytoprostanes F1 exert biological activities in plants and/or animals. PMID:11080305

  3. Feral rice from introgression of weedy rice genes into transgenic herbicide-resistant hybrid-rice progeny.

    PubMed

    Zhang, Jingxu; Kang, Ye; Valverde, Bernal E; Dai, Weimin; Song, Xiaoling; Qiang, Sheng

    2018-06-05

    Pollen-mediated herbicide-resistance transgene flow occurs bidirectionally between transgenic cultivated rice and weedy rice. The potential risk of weedy traits introgressing into hybrid rice is underestimated and poorly understood. Two of each glufosinate-resistant transgenic rice varieties and hybrid rice (F1) and their succeeding generations (F2-F4) were planted for three years in weedy-rice-free field plots adjacent to experimental weedy-rice fields. Weedy-rice-like (feral) plants, both glufosinate-resistant and with red-pericarp seed, were initially found only among the F3 generations of the two glufosinate-resistant transgenic hybrid rice. The composite fitness (an index based on eight productivity and weediness traits) of the feral progeny was significantly higher than that of glufosinate-resistant transgenic hybrid rice (the original female parent of feral progeny) under common monoculture garden conditions. Hybrid rice progeny segregated into individuals of variable height and extended flowering. Hybrid rice F2 generations had higher outcrossing rates by pollen reception (0.96%-1.65%) than their progenitors (0.07%-0.98%). Herbicide-resistant weedy rice can rapidly arise by pollen-mediated gene flow from weedy to transgenic hybrid rice. Their segregating pollen-receptive progeny pose greater agro-ecological risk than transgenic varieties. The safety assessment and management regulations for transgenic hybrid rice should take into account the risk of bidirectional gene flow.

  4. Prion replication without host adaptation during interspecies transmissions.

    PubMed

    Bian, Jifeng; Khaychuk, Vadim; Angers, Rachel C; Fernández-Borges, Natalia; Vidal, Enric; Meyerett-Reid, Crystal; Kim, Sehun; Calvi, Carla L; Bartz, Jason C; Hoover, Edward A; Agrimi, Umberto; Richt, Jürgen A; Castilla, Joaquín; Telling, Glenn C

    2017-01-31

    Adaptation of prions to new species is thought to reflect the capacity of the host-encoded cellular form of the prion protein (PrP C ) to selectively propagate optimized prion conformations from larger ensembles generated in the species of origin. Here we describe an alternate replicative process, termed nonadaptive prion amplification (NAPA), in which dominant conformers bypass this requirement during particular interspecies transmissions. To model susceptibility of horses to prions, we produced transgenic (Tg) mice expressing cognate PrP C Although disease transmission to only a subset of infected TgEq indicated a significant barrier to EqPrP C conversion, the resulting horse prions unexpectedly failed to cause disease upon further passage to TgEq. TgD expressing deer PrP C was similarly refractory to deer prions from diseased TgD infected with mink prions. In both cases, the resulting prions transmitted to mice expressing PrP C from the species of prion origin, demonstrating that transmission barrier eradication of the originating prions was ephemeral and adaptation superficial in TgEq and TgD. Horse prions produced in vitro by protein misfolding cyclic amplification of mouse prions using horse PrP C also failed to infect TgEq but retained tropism for wild-type mice. Concordant patterns of neuropathology and prion deposition in susceptible mice infected with NAPA prions and the corresponding prion of origin confirmed preservation of strain properties. The comparable responses of both prion types to guanidine hydrochloride denaturation indicated this occurs because NAPA precludes selection of novel prion conformations. Our findings provide insights into mechanisms regulating interspecies prion transmission and a framework to reconcile puzzling epidemiological features of certain prion disorders.

  5. Prion replication without host adaptation during interspecies transmissions

    PubMed Central

    Bian, Jifeng; Khaychuk, Vadim; Angers, Rachel C.; Fernández-Borges, Natalia; Meyerett-Reid, Crystal; Kim, Sehun; Calvi, Carla L.; Bartz, Jason C.; Hoover, Edward A.; Agrimi, Umberto; Richt, Jürgen A.; Castilla, Joaquín; Telling, Glenn C.

    2017-01-01

    Adaptation of prions to new species is thought to reflect the capacity of the host-encoded cellular form of the prion protein (PrPC) to selectively propagate optimized prion conformations from larger ensembles generated in the species of origin. Here we describe an alternate replicative process, termed nonadaptive prion amplification (NAPA), in which dominant conformers bypass this requirement during particular interspecies transmissions. To model susceptibility of horses to prions, we produced transgenic (Tg) mice expressing cognate PrPC. Although disease transmission to only a subset of infected TgEq indicated a significant barrier to EqPrPC conversion, the resulting horse prions unexpectedly failed to cause disease upon further passage to TgEq. TgD expressing deer PrPC was similarly refractory to deer prions from diseased TgD infected with mink prions. In both cases, the resulting prions transmitted to mice expressing PrPC from the species of prion origin, demonstrating that transmission barrier eradication of the originating prions was ephemeral and adaptation superficial in TgEq and TgD. Horse prions produced in vitro by protein misfolding cyclic amplification of mouse prions using horse PrPC also failed to infect TgEq but retained tropism for wild-type mice. Concordant patterns of neuropathology and prion deposition in susceptible mice infected with NAPA prions and the corresponding prion of origin confirmed preservation of strain properties. The comparable responses of both prion types to guanidine hydrochloride denaturation indicated this occurs because NAPA precludes selection of novel prion conformations. Our findings provide insights into mechanisms regulating interspecies prion transmission and a framework to reconcile puzzling epidemiological features of certain prion disorders. PMID:28096357

  6. Speciation and reduced hybrid female fertility in house mice.

    PubMed

    Suzuki, Taichi A; Nachman, Michael W

    2015-09-01

    In mammals, intrinsic postzygotic isolation has been well studied in males but has been less studied in females, despite the fact that female gametogenesis and pregnancy provide arenas for hybrid sterility or inviability that are absent in males. Here, we asked whether inviability or sterility is observed in female hybrids of Mus musculus domesticus and M. m. musculus, taxa which hybridize in nature and for which male sterility has been well characterized. We looked for parent-of-origin growth phenotypes by measuring adult body weights in F1 hybrids. We evaluated hybrid female fertility by crossing F1 females to a tester male and comparing multiple reproductive parameters between intrasubspecific controls and intersubspecific hybrids. Hybrid females showed no evidence of parent-of-origin overgrowth or undergrowth, providing no evidence for reduced viability. However, hybrid females had smaller litter sizes, reduced embryo survival, fewer ovulations, and fewer small follicles relative to controls. Significant variation in reproductive parameters was seen among different hybrid genotypes, suggesting that hybrid incompatibilities are polymorphic within subspecies. Differences in reproductive phenotypes in reciprocal genotypes were observed and are consistent with cyto-nuclear incompatibilities or incompatibilities involving genomic imprinting. These findings highlight the potential importance of reduced hybrid female fertility in the early stages of speciation. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  7. High-Resolution Structure and Mechanism of an F/V-Hybrid Rotor Ring in a Na+-coupled ATP Synthase

    PubMed Central

    Matthies, Doreen; Zhou, Wenchang; Klyszejko, Adriana L.; Anselmi, Claudio; Yildiz, Özkan; Brandt, Karsten; Müller, Volker; Faraldo-Gómez, José D.; Meier, Thomas

    2014-01-01

    All rotary ATPases catalyze the interconversion of ATP and ADP-Pi through a mechanism that is coupled to the transmembrane flow of H+ or Na+. Physiologically, however, F/A-type enzymes specialize in ATP synthesis driven by downhill ion diffusion, while eukaryotic V-type ATPases function as ion pumps. To begin to rationalize the molecular basis for this functional differentiation, we solved the crystal structure of the Na+-driven membrane rotor of the Acetobacterium woodii ATP synthase, at 2.1 Å resolution. Unlike known structures, this rotor ring is a 9:1 heteromer of F- and V-type c-subunits, and therefore features a hybrid configuration of ion-binding sites along its circumference. Molecular and kinetic simulations are used to dissect the mechanisms of Na+ recognition and rotation of this c-ring, and to explain the functional implications of the V-type c-subunit. These structural and mechanistic insights indicate an evolutionary path between synthases and pumps involving adaptations in the rotor ring. PMID:25381992

  8. Hybrid male sterility between Drosophila willistoni species is caused by male failure to transfer sperm during copulation.

    PubMed

    Civetta, Alberto; Gaudreau, Chelsea

    2015-05-01

    The biological concept of species stresses the importance of understanding what mechanisms maintain species reproductively isolated from each other. Often such mechanisms are divided into premating and postmating, with the latest being the result of either prezygotic or postzygotic isolation barriers. Drosophila willistoni quechua and Drosophila willistoni willistoni are two subspecies that experience reproductive isolation. When a D. w. quechua female is crossed with a D. w. willistoni male, the hybrid males (F1QW) are unable to father progeny; however, the reciprocal cross produces fertile hybrids. Thus, the mechanism of isolation is unidirectional hybrid male sterility. However, the sterile F1QW males contain large amounts of motile sperm. Here we explore whether pre-copulatory or post-copulatory pre-zygotic mechanisms serve as major deterrents in the ability of F1QW males to father progeny. Comparisons of parental and hybrid males copulation durations showed no significant reduction in copulation duration of F1QW males. Interrupted copulations of the parental species confirmed that sperm transfer occurs before the minimum copulation duration registered for F1QW males. However, we found that when females mate with F1QW males, sperm is not present inside the female storage organs and that the lack of sperm in storage is due to failure to transfer sperm rather than spillage or active sperm dumping by females. Sterility of F1QW hybrid males is primarily driven by their inability to transfer sperm during copulation.

  9. Pentaploid Wheat Hybrids: Applications, Characterisation, and Challenges

    PubMed Central

    Padmanaban, Sriram; Zhang, Peng; Hare, Ray A.; Sutherland, Mark W.; Martin, Anke

    2017-01-01

    Interspecific hybridisation between hexaploid and tetraploid wheat species leads to the development of F1 pentaploid hybrids with unique chromosomal constitutions. Pentaploid hybrids derived from bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum spp. durum Desf.) crosses can improve the genetic background of either parent by transferring traits of interest. The genetic variability derived from bread and durum wheat and transferred into pentaploid hybrids has the potential to improve disease resistance, abiotic tolerance, and grain quality, and to enhance agronomic characters. Nonetheless, pentaploid wheat hybrids have not been fully exploited in breeding programs aimed at improving crops. There are several potential barriers for efficient pentaploid wheat production, such as low pollen compatibility, poor seed set, failed seedling establishment, and frequent sterility in F1 hybrids. However, most of the barriers can be overcome by careful selection of the parental genotypes and by employing the higher ploidy level genotype as the maternal parent. In this review, we summarize the current research on pentaploid wheat hybrids and analyze the advantages and pitfalls of current methods used to assess pentaploid-derived lines. Furthermore, we discuss current and potential applications in commercial breeding programs and future directions for research into pentaploid wheat. PMID:28367153

  10. WEB-BASED INTERSPECIES CORRELATION ESTIMATION (WEB-ICE) FOR ACUTE TOXICITY: USER MANUAL V2

    EPA Science Inventory

    Predictive toxicological models are integral to environmental risk Assessment where data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ...

  11. X Chromosome Control of Meiotic Chromosome Synapsis in Mouse Inter-Subspecific Hybrids

    PubMed Central

    Bhattacharyya, Tanmoy; Reifova, Radka; Gregorova, Sona; Simecek, Petr; Gergelits, Vaclav; Mistrik, Martin; Martincova, Iva; Pialek, Jaroslav; Forejt, Jiri

    2014-01-01

    Hybrid sterility (HS) belongs to reproductive isolation barriers that safeguard the integrity of species in statu nascendi. Although hybrid sterility occurs almost universally among animal and plant species, most of our current knowledge comes from the classical genetic studies on Drosophila interspecific crosses or introgressions. With the house mouse subspecies Mus m. musculus and Mus m. domesticus as a model, new research tools have become available for studies of the molecular mechanisms and genetic networks underlying HS. Here we used QTL analysis and intersubspecific chromosome substitution strains to identify a 4.7 Mb critical region on Chromosome X (Chr X) harboring the Hstx2 HS locus, which causes asymmetrical spermatogenic arrest in reciprocal intersubspecific F1 hybrids. Subsequently, we mapped autosomal loci on Chrs 3, 9 and 13 that can abolish this asymmetry. Combination of immunofluorescent visualization of the proteins of synaptonemal complexes with whole-chromosome DNA FISH on pachytene spreads revealed that heterosubspecific, unlike consubspecific, homologous chromosomes are predisposed to asynapsis in F1 hybrid male and female meiosis. The asynapsis is under the trans- control of Hstx2 and Hst1/Prdm9 hybrid sterility genes in pachynemas of male but not female hybrids. The finding concurred with the fertility of intersubpecific F1 hybrid females homozygous for the Hstx2Mmm allele and resolved the apparent conflict with the dominance theory of Haldane's rule. We propose that meiotic asynapsis in intersubspecific hybrids is a consequence of cis-acting mismatch between homologous chromosomes modulated by the trans-acting Hstx2 and Prdm9 hybrid male sterility genes. PMID:24516397

  12. X chromosome control of meiotic chromosome synapsis in mouse inter-subspecific hybrids.

    PubMed

    Bhattacharyya, Tanmoy; Reifova, Radka; Gregorova, Sona; Simecek, Petr; Gergelits, Vaclav; Mistrik, Martin; Martincova, Iva; Pialek, Jaroslav; Forejt, Jiri

    2014-02-01

    Hybrid sterility (HS) belongs to reproductive isolation barriers that safeguard the integrity of species in statu nascendi. Although hybrid sterility occurs almost universally among animal and plant species, most of our current knowledge comes from the classical genetic studies on Drosophila interspecific crosses or introgressions. With the house mouse subspecies Mus m. musculus and Mus m. domesticus as a model, new research tools have become available for studies of the molecular mechanisms and genetic networks underlying HS. Here we used QTL analysis and intersubspecific chromosome substitution strains to identify a 4.7 Mb critical region on Chromosome X (Chr X) harboring the Hstx2 HS locus, which causes asymmetrical spermatogenic arrest in reciprocal intersubspecific F1 hybrids. Subsequently, we mapped autosomal loci on Chrs 3, 9 and 13 that can abolish this asymmetry. Combination of immunofluorescent visualization of the proteins of synaptonemal complexes with whole-chromosome DNA FISH on pachytene spreads revealed that heterosubspecific, unlike consubspecific, homologous chromosomes are predisposed to asynapsis in F1 hybrid male and female meiosis. The asynapsis is under the trans- control of Hstx2 and Hst1/Prdm9 hybrid sterility genes in pachynemas of male but not female hybrids. The finding concurred with the fertility of intersubpecific F1 hybrid females homozygous for the Hstx2(Mmm) allele and resolved the apparent conflict with the dominance theory of Haldane's rule. We propose that meiotic asynapsis in intersubspecific hybrids is a consequence of cis-acting mismatch between homologous chromosomes modulated by the trans-acting Hstx2 and Prdm9 hybrid male sterility genes.

  13. f1: a code to compute Appell's F1 hypergeometric function

    NASA Astrophysics Data System (ADS)

    Colavecchia, F. D.; Gasaneo, G.

    2004-02-01

    In this work we present the FORTRAN code to compute the hypergeometric function F1( α, β1, β2, γ, x, y) of Appell. The program can compute the F1 function for real values of the variables { x, y}, and complex values of the parameters { α, β1, β2, γ}. The code uses different strategies to calculate the function according to the ideas outlined in [F.D. Colavecchia et al., Comput. Phys. Comm. 138 (1) (2001) 29]. Program summaryTitle of the program: f1 Catalogue identifier: ADSJ Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSJ Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Licensing provisions: none Computers: PC compatibles, SGI Origin2∗ Operating system under which the program has been tested: Linux, IRIX Programming language used: Fortran 90 Memory required to execute with typical data: 4 kbytes No. of bits in a word: 32 No. of bytes in distributed program, including test data, etc.: 52 325 Distribution format: tar gzip file External subprograms used: Numerical Recipes hypgeo [W.H. Press et al., Numerical Recipes in Fortran 77, Cambridge Univ. Press, 1996] or chyp routine of R.C. Forrey [J. Comput. Phys. 137 (1997) 79], rkf45 [L.F. Shampine and H.H. Watts, Rep. SAND76-0585, 1976]. Keywords: Numerical methods, special functions, hypergeometric functions, Appell functions, Gauss function Nature of the physical problem: Computing the Appell F1 function is relevant in atomic collisions and elementary particle physics. It is usually the result of multidimensional integrals involving Coulomb continuum states. Method of solution: The F1 function has a convergent-series definition for | x|<1 and | y|<1, and several analytic continuations for other regions of the variable space. The code tests the values of the variables and selects one of the precedent cases. In the convergence region the program uses the series definition near the origin of coordinates, and a numerical integration of the third-order differential

  14. Interspecies Systems Biology Uncovers Metabolites Affecting C. elegans Gene Expression and Life History Traits

    PubMed Central

    Watson, Emma; MacNeil, Lesley T.; Ritter, Ashlyn D.; Yilmaz, L. Safak; Rosebrock, Adam P.; Caudy, Amy A.; Walhout, Albertha J. M.

    2014-01-01

    SUMMARY Diet greatly influences gene expression and physiology. In mammals, elucidating the effects and mechanisms of individual nutrients is challenging due to the complexity of both the animal and its diet. Here we used an interspecies systems biology approach with Caenorhabditis elegans and two if its bacterial diets, Escherichia coli and Comamonas aquatica, to identify metabolites that affect the animal’s gene expression and physiology. We identify vitamin B12 as the major dilutable metabolite provided by Comamonas aq. that regulates gene expression, accelerates development and reduces fertility, but does not affect lifespan. We find that vitamin B12 has a dual role in the animal: it affects development and fertility via the methionine/S-Adenosylmethionine (SAM) cycle and breaks down the short-chain fatty acid propionic acid preventing its toxic buildup. Our interspecies systems biology approach provides a paradigm for understanding complex interactions between diet and physiology. PMID:24529378

  15. Performance of hybrid progeny formed between genetically modified herbicide-tolerant soybean and its wild ancestor

    PubMed Central

    Guan, Zheng-Jun; Zhang, Peng-Fei; Wei, Wei; Mi, Xiang-Cheng; Kang, Ding-Ming; Liu, Biao

    2015-01-01

    Gene flow from genetically modified (GM) crops to wild relatives might affect the evolutionary dynamics of weedy populations and result in the persistence of escaped genes. To examine the effects of this gene flow, the growth of F1 hybrids that were formed by pollinating wild soybean (Glycine soja) with glyphosate-tolerant GM soybean (G. max) or its non-GM counterpart was examined in a greenhouse. The wild soybean was collected from two geographical populations in China. The performance of the wild soybean and the F2 hybrids was further explored in a field trial. Performance was measured by several vegetative and reproductive growth parameters, including the vegetative growth period, pod number, seed number, above-ground biomass and 100-seed weight. The pod setting percentage was very low in the hybrid plants. Genetically modified hybrid F1 plants had a significantly longer period of vegetative growth, higher biomass and lower 100-seed weight than the non-GM ones. The 100-seed weight of both F1 and F2 hybrids was significantly higher than that of wild soybean in both the greenhouse and the field trial. No difference in plant growth was found between GM and non-GM F2 hybrids in the field trial. The herbicide-resistant gene appeared not to adversely affect the growth of introgressed wild soybeans, suggesting that the escaped transgene could persist in nature in the absence of herbicide use. PMID:26507568

  16. Prdm9 incompatibility controls oligospermia and delayed fertility but no selfish transmission in mouse intersubspecific hybrids.

    PubMed

    Flachs, Petr; Bhattacharyya, Tanmoy; Mihola, Ondřej; Piálek, Jaroslav; Forejt, Jiří; Trachtulec, Zdenek

    2014-01-01

    PR-domain 9 (Prdm9) is the first hybrid sterility gene identified in mammals. The incompatibility between Prdm9 from Mus musculus domesticus (Mmd; the B6 strain) and the Hstx2 region of chromosome (Chr) X from M. m. musculus (Mmm; the PWD strain) participates in the complete meiotic arrest of mouse intersubspecific (PWD×B6)F1 hybrid males. Other studies suggest that also semisterile intersubspecific hybrids are relevant for mouse speciation, but the genes responsible remain unknown. To investigate the causes of this semisterility, we analyzed the role of Prdm9 and Chr X in hybrids resulting from the crosses of PWK, another Mmm-derived inbred strain. We demonstrate that Prdm9 and Chr X control the partial meiotic arrest and reduced sperm count in (PWK×B6)F1 males. Asynapsis of heterosubspecific chromosomes and semisterility were partially suppressed by removal of the B6 allele of Prdm9. Polymorphisms between PWK and PWD on Chr X but not in the Prdm9 region were responsible for the modification of the outcome of Prdm9-Chr X F1 hybrid incompatibility. Furthermore, (PWK×B6)F1 hybrid males displayed delayed fertility dependent on the Prdm9 incompatibility. While the Drosophila hybrid sterility gene Overdrive causes both delayed fertility and increased transmission of its own chromosome to the offspring, the segregation of Chr X and the Prdm9 region from the mouse (PWK×B6)F1 males was normal. Our results indicate extended functional consequences of Prdm9-Chr X intersubspecific incompatibility on the fertility of hybrids and should influence the design of fertility analyses in hybrid zones and of laboratory crosses between Mmm and Mmd strains.

  17. A prototype hybrid 7π quinone-fused 1,3,2-dithiazolyl radical.

    PubMed

    Decken, A; Mailman, A; Passmore, J; Rautiainen, J M; Scherer, W; Scheidt, E-W

    2011-01-28

    Reaction of 1,4-naphthoquinone and SNSMF(6) (M = As, Sb) in SO(2) solution in a 1 : 2 molar ratio led to the naphthoquinone fused 1,3,2-dithiazolylium salts, 3MF(6) quantitatively by multinuclear NMR (87% isolated yield of 3SbF(6)) via the cycloaddition and oxidative dehydrogenation chemistry of SNS(+) with formation of NH(4)SbF(6) and S(8). The product 3SbF(6) was fully characterized by IR, Raman, multinuclear {(1)H, (13)C, (14)N} NMR, elemental analysis, cyclic voltammetry and single crystal X-ray crystallography. The reduction of 3SbF(6) with ferrocene (Cp(2)Fe) in refluxing acetonitrile (CH(3)CN) led to the first isolation of a fused quinone-thiazyl radical, 3˙ in 73% yield. The prototype hybrid quinone-thiazyl radical 3˙ was fully characterized by IR, Raman microscopy, EI-MS, elemental analysis, solution and solid state EPR, magnetic susceptibility (2-370 K) and was found to form π*-π* dimers in the solid state as determined by single crystal X-ray crystallography. Furthermore, the thermal decomposition of 3˙ led to a novel quinone-fused 1,2,3,4-tetrathiine, 10 (x = 2) and the known 1,2,5-thiadiazole, 11. The energetics of the cycloadditon and oxidative dehydrogenation chemistry of SNS(+) and 1,4-naphthoquinone leading to 3SbF(6) were estimated in the gas phase and SO(2) solution by DFT calculations (PBE0/6-311G(d)) and lattice enthalpies obtained by the volume based thermodynamic (VBT) approach in the solid state. The gas phase ion energetics (ionization potential (IP) and electron affinity (EA)) of 3˙ are compared to related 1,3,2- and 1,2,3-dithiazolyl radicals.

  18. Susceptibility of field populations of the fall armyworm (Lepidoptera: Noctuidae) from Florida and Puerto Rico to purified Cry1F protein and corn leaf tissue containing single and pyramided Bt genes

    USDA-ARS?s Scientific Manuscript database

    Larval survival of Cry1F-susceptible (FL), -resistant (PR and Cry1F-RR), and -heterozygous (FL x PR and Cry1F-RS) populations of the fall armyworm, Spodoptera frugiperda (J.E. Smith) to purified Cry1F protein and corn leaf tissue of seven Bacillus thuringiensis (Bt) corn hybrids and five non-Bt corn...

  19. Epistasis modifies the dominance of loci causing hybrid male sterility in the Drosophila pseudoobscura species group

    PubMed Central

    Chang, Audrey S.; Noor, Mohamed A. F.

    2009-01-01

    Speciation, the evolution of reproductive isolation between populations, serves as the driving force for generating biodiversity. Postzygotic barriers to gene flow, such as F1 hybrid sterility and inviability, play important roles in the establishment and maintenance of biological species. F1 hybrid incompatibilities in taxa that obey Haldane's rule, the observation that the heterogametic sex suffers greater hybrid fitness problems than the homogametic sex, are thought to often result from interactions between recessive-acting X-linked loci and dominant-acting autosomal loci. Because they play such prominent roles in producing hybrid incompatibilities, we examine the dominance and nature of epistasis between alleles derived from Drosophila persimilis that confer hybrid male sterility in the genetic background of its sister species, D. pseudoobscura bogotana. We show that epistasis elevates the apparent dominance of individually recessive-acting QTL such that they can contribute to F1 hybrid sterility. These results have important implications for assumptions underlying theoretical models of hybrid incompatibilities and may offer a possible explanation for why, to date identification of dominant-acting autosomal “speciation genes” has been challenging. PMID:19686263

  20. Epistasis modifies the dominance of loci causing hybrid male sterility in the Drosophila pseudoobscura species group.

    PubMed

    Chang, Audrey S; Noor, Mohamed A F

    2010-01-01

    Speciation, the evolution of reproductive isolation between populations, serves as the driving force for generating biodiversity. Postzygotic barriers to gene flow, such as F(1) hybrid sterility and inviability, play important roles in the establishment and maintenance of biological species. F(1) hybrid incompatibilities in taxa that obey Haldane's rule, the observation that the heterogametic sex suffers greater hybrid fitness problems than the homogametic sex, are thought to often result from interactions between recessive-acting X-linked loci and dominant-acting autosomal loci. Because they play such prominent roles in producing hybrid incompatibilities, we examine the dominance and nature of epistasis between alleles derived from Drosophila persimilis that confer hybrid male sterility in the genetic background of its sister species, D. pseudoobscura bogotana. We show that epistasis elevates the apparent dominance of individually recessive-acting QTL such that they can contribute to F(1) hybrid sterility. These results have important implications for assumptions underlying theoretical models of hybrid incompatibilities and may offer a possible explanation for why, to date, identification of dominant-acting autosomal "speciation genes" has been challenging.

  1. General and specific combining ability of F1-hybrid sweet sorghum in Thailand

    USDA-ARS?s Scientific Manuscript database

    Sweet sorghum (Sorghum bicolor (L.) Moench) is a promising biofuel crop that accumulates fermentable sugar in the stalk and can be directly fermented as bioethanol. Currently, most of sweet sorghum cultivars are pure lines. However, developing high-yielding hybrids has many advantages. To date there...

  2. Unilateral incompatibility gene ui1.1 encodes an S-locus F-box protein expressed in pollen of Solanum species.

    PubMed

    Li, Wentao; Chetelat, Roger T

    2015-04-07

    Unilateral interspecific incompatibility (UI) is a postpollination, prezygotic reproductive barrier that prevents hybridization between related species when the female parent is self-incompatible (SI) and the male parent is self-compatible (SC). In tomato and related Solanum species, two genes, ui1.1 and ui6.1, are required for pollen compatibility on pistils of SI species or hybrids. We previously showed that ui6.1 encodes a Cullin1 (CUL1) protein. Here we report that ui1.1 encodes an S-locus F-box (SLF) protein. The ui1.1 gene was mapped to a 0.43-cM, 43.2-Mbp interval at the S-locus on chromosome 1, but positional cloning was hampered by low recombination frequency. We hypothesized that ui1.1 encodes an SLF protein(s) that interacts with CUL1 and Skp1 proteins to form an SCF-type (Skp1, Cullin1, F-box) ubiquitin E3 ligase complex. We identified 23 SLF genes in the S. pennellii genome, of which 19 were also represented in cultivated tomato (S. lycopersicum). Data from recombination events, expression analysis, and sequence annotation highlighted 11 S. pennellii genes as candidates. Genetic transformations demonstrated that one of these, SpSLF-23, is sufficient for ui1.1 function. A survey of cultivated and wild tomato species identified SLF-23 orthologs in each of the SI species, but not in the SC species S. lycopersicum, S. cheesmaniae, and S. galapagense, pollen of which lacks ui1.1 function. These results demonstrate that pollen compatibility in UI is mediated by protein degradation through the ubiquitin-proteasome pathway, a mechanism related to that which controls pollen recognition in SI.

  3. The role of receptor binding specificity in interspecies transmission of influenza viruses

    PubMed Central

    Imai, Masaki; Kawaoka, Yoshihiro

    2017-01-01

    Influenza A virus infection begins with the binding of the hemagglutinin (HA) glycoprotein to sialic acid-containing receptors on the surface of the target cell. Avian influenza viruses, including avian H5N1, H7, and H9N2 viruses, can occasionally cross the species barrier and infect humans; however, these viruses do not spread efficiently from person to person, perhaps, in part, due to differences in the receptor-binding specificities of human and avian influenza viruses. The HAs of avian influenza viruses must adapt to receptors in humans to acquire efficient human-to-human transmissibility. In this review, we discuss the receptor binding specificity of influenza A viruses and its role in interspecies transmission. PMID:22445963

  4. Trichostatin A (TSA) improves the development of rabbit-rabbit intraspecies cloned embryos, but not rabbit-human interspecies cloned embryos.

    PubMed

    Shi, Li-Hong; Miao, Yi-Liang; Ouyang, Ying-Chun; Huang, Jun-Cheng; Lei, Zi-Li; Yang, Ji-Wen; Han, Zhi-Ming; Song, Xiang-Fen; Sun, Qing-Yuan; Chen, Da-Yuan

    2008-03-01

    The interspecies somatic cell nuclear transfer (iSCNT) technique for therapeutic cloning gives great promise for treatment of many human diseases. However, the incomplete nuclear reprogramming and the low blastocyst rate of iSCNT are still big problems. Herein, we observed the effect of TSA on the development of rabbit-rabbit intraspecies and rabbit-human interspecies cloned embryos. After treatment with TSA for 6 hr during activation, we found that the blastocyst rate of rabbit-rabbit cloned embryos was more than two times higher than that of untreated embryos; however, the blastocyst rate of TSA-treated rabbit-human interspecies cloned embryos decreased. We also found evident time-dependent histone deacetylation-reacetylation changes in rabbit-rabbit cloned embryos, but not in rabbit-human cloned embryos from fusion to 6 hr after activation. Our results suggest that TSA-treatment does not improve blastocyst development of rabbit-human iSCNT embryos and that abnormal histone deacetylation-reacetylation changes in iSCNT embryos may account for their poor blastocyst development. (c) 2008 Wiley-Liss, Inc.

  5. Interspecies communication between plant and mouse gut host cells through edible plant derived exosome-like nanoparticles

    PubMed Central

    Mu, Jingyao; Zhuang, Xiaoying; Wang, Qilong; Jiang, Hong; Deng, Zhong-Bin; Wang, Baomei; Zhang, Lifeng; Kakar, Sham; Jun, Yan; Miller, Donald; Zhang, Huang-Ge

    2015-01-01

    Scope Exosomes, small vesicles participating in intercellular communication have been extensively studied recently; however, the role of edible plant derived exosomes in interspecies communication has not been investigated. Here, we investigate the biological effects of edible plant derived exosome-like nanoparticles (EPDEN) on mammalian cells. Methods and results In this study, exosome-like nanoparticles from four edible plants were isolated and characterized. We show that these EPDENs contain proteins, lipids and microRNA. EPDENs are taken up by intestinal macrophages and stem cells. The results generated from EPDEN transfected macrophages indicate that ginger EPDENs preferentially induce the expression of the anti-oxidation gene, heme oxygenase-1 (HO-1) and the anti-inflammatory cytokine, IL-10; whereas grapefruit, ginger, and carrot EPDENs promote activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Furthermore, analysis of the intestines of canonical Wnt reporter mice, i.e., B6.Cg-Tg(BAT-lacZ)3Picc/J mice, revealed that the numbers of β-galactosidase+ (β-Gal) intestinal crypts are increased, suggesting that EPDEN treatment of mice leads to Wnt mediated activation of the Tcf4 transcription machinery in the crypts. Conclusion The data suggest a role for EPDEN mediated interspecies communication by inducing expression of genes for anti-inflammation cytokines, anti-oxidation and activation of Wnt signaling, which are crucial for maintaining intestinal homeostasis. PMID:24842810

  6. 700 F hybrid capacitors cells composed of activated carbon and Li4Ti5O12 microspheres with ultra-long cycle life

    NASA Astrophysics Data System (ADS)

    Ruan, Dianbo; Kim, Myeong-Seong; Yang, Bin; Qin, Jun; Kim, Kwang-Bum; Lee, Sang-Hyun; Liu, Qiuxiang; Tan, Lei; Qiao, Zhijun

    2017-10-01

    To address the large-scale application demands of high energy density, high power density, and long cycle lifetime, 700-F hybrid capacitor pouch cells have been prepared, comprising ∼240-μm-thick activated carbon cathodes, and ∼60-μm-thick Li4Ti5O12 anodes. Microspherical Li4Ti5O12 (M-LTO) synthesized by spray-drying features 200-400 nm primary particles and interconnected nanopore structures. M-LTO half-cells exhibits high specific capacities (175 mAhh g-1), good rate capabilities (148 mAhh g-1 at 20 C), and ultra-long cycling stabilities (90% specific capacity retention after 10,000 cycles). In addition, the obtained hybrid capacitors comprising activated carbon (AC) and M-LTO shows excellent cell performances, achieving a maximum energy density of 51.65 Wh kg-1, a maximum power density of 2466 W kg-1, and ∼92% capacitance retention after 10,000 cycles, thus meeting the demands for large-scale applications such as trolleybuses.

  7. Metagenomic insight into methanogenic reactors promoting direct interspecies electron transfer via granular activated carbon.

    PubMed

    Park, Jeong-Hoon; Park, Jong-Hun; Je Seong, Hoon; Sul, Woo Jun; Jin, Kang-Hyun; Park, Hee-Deung

    2018-07-01

    To provide insight into direct interspecies electron transfer via granular activated carbon (GAC), the effect of GAC supplementation on anaerobic digestion was evaluated. Compared to control samples, the GAC supplementation increased the total amount of methane production and its production rate by 31% and 72%, respectively. 16S rDNA sequencing analysis revealed a shift in the archaeal community composition; the Methanosarcina proportion decreased 17%, while the Methanosaeta proportion increased 5.6%. Metagenomic analyses based on shotgun sequencing demonstrated that the abundance of pilA and omcS genes belonging to Geobacter species decreased 69.4% and 29.4%, respectively. Furthermore, the analyses suggested a carbon dioxide reduction pathway rather than an acetate decarboxylation pathway for methane formation. Taken together, these results suggest that GAC improved methane production performance by shifting the microbial community and altering functional genes associated with direct interspecies electron transfer via conductive materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Hybrid Parallel Contour Trees, Version 1.0

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

    Sewell, Christopher; Fasel, Patricia; Carr, Hamish

    A common operation in scientific visualization is to compute and render a contour of a data set. Given a function of the form f : R^d -> R, a level set is defined as an inverse image f^-1(h) for an isovalue h, and a contour is a single connected component of a level set. The Reeb graph can then be defined to be the result of contracting each contour to a single point, and is well defined for Euclidean spaces or for general manifolds. For simple domains, the graph is guaranteed to be a tree, and is called the contourmore » tree. Analysis can then be performed on the contour tree in order to identify isovalues of particular interest, based on various metrics, and render the corresponding contours, without having to know such isovalues a priori. This code is intended to be the first data-parallel algorithm for computing contour trees. Our implementation will use the portable data-parallel primitives provided by Nvidia’s Thrust library, allowing us to compile our same code for both GPUs and multi-core CPUs. Native OpenMP and purely serial versions of the code will likely also be included. It will also be extended to provide a hybrid data-parallel / distributed algorithm, allowing scaling beyond a single GPU or CPU.« less

  9. Hybrid Systems: Computation and Control.

    DTIC Science & Technology

    1999-02-17

    computer science ; Vol. 1386) ISBN 3 -540-64358- 3 CR Subject Classification (1991): C.l.m, C. 3 , D.2.1,F.3.1, F.1.2, J.2 ISSN 0302-9743 ISBN 3 -540...64358- 3 Springer-Verlag Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material...10632061 06/3142 - 5 4 3 2 1 0 Printed on acid-free paper Preface This volume contains the proceedings of the First International Workshop on Hybrid Systems

  10. Cross-Resistance between Cry1 Proteins in Fall Armyworm (Spodoptera frugiperda) May Affect the Durability of Current Pyramided Bt Maize Hybrids in Brazil

    PubMed Central

    Bernardi, Daniel; Salmeron, Eloisa; Horikoshi, Renato Jun; Bernardi, Oderlei; Dourado, Patrick Marques; Carvalho, Renato Assis; Martinelli, Samuel; Head, Graham P.; Omoto, Celso

    2015-01-01

    Genetically modified plants expressing insecticidal proteins from Bacillus thuringiensis (Bt) offer valuable options for managing insect pests with considerable environmental and economic benefits. Despite the benefits provided by Bt crops, the continuous expression of these insecticidal proteins imposes strong selection for resistance in target pest populations. Bt maize (Zea mays) hybrids have been successful in controlling fall armyworm (Spodoptera frugiperda), the main maize pest in Brazil since 2008; however, field-evolved resistance to the protein Cry1F has recently been reported. Therefore it is important to assess the possibility of cross-resistance between Cry1F and other Cry proteins expressed in Bt maize hybrids. In this study, an F2 screen followed by subsequent selection on MON 89034 maize was used to select an S. frugiperda strain (RR) able to survive on the Bt maize event MON 89034, which expresses the Cry1A.105 and Cry2Ab2 proteins. Field-collected insects from maize expressing the Cry1F protein (event TC1507) represented most of the positive (resistance allele-containing) (iso)families found. The RR strain showed high levels of resistance to Cry1F, which apparently also conferred high levels of cross resistance to Cry1A.105 and Cry1Ab, but had only low-level (10-fold) resistance to Cry2Ab2. Life history studies to investigate fitness costs associated with the resistance in RR strain revealed only small reductions in reproductive rate when compared to susceptible and heterozygous strains, but the RR strain produced 32.2% and 28.4% fewer females from each female relative to the SS and RS (pooled) strains, respectively. Consistent with the lack of significant resistance to Cry2Ab2, MON 89034 maize in combination with appropriate management practices continues to provide effective control of S. frugiperda in Brazil. Nevertheless, the occurrence of Cry1F resistance in S. frugiperda across Brazil, and the cross-resistance to Cry1Ab and Cry1A.105

  11. Cross-Resistance between Cry1 Proteins in Fall Armyworm (Spodoptera frugiperda) May Affect the Durability of Current Pyramided Bt Maize Hybrids in Brazil.

    PubMed

    Bernardi, Daniel; Salmeron, Eloisa; Horikoshi, Renato Jun; Bernardi, Oderlei; Dourado, Patrick Marques; Carvalho, Renato Assis; Martinelli, Samuel; Head, Graham P; Omoto, Celso

    2015-01-01

    Genetically modified plants expressing insecticidal proteins from Bacillus thuringiensis (Bt) offer valuable options for managing insect pests with considerable environmental and economic benefits. Despite the benefits provided by Bt crops, the continuous expression of these insecticidal proteins imposes strong selection for resistance in target pest populations. Bt maize (Zea mays) hybrids have been successful in controlling fall armyworm (Spodoptera frugiperda), the main maize pest in Brazil since 2008; however, field-evolved resistance to the protein Cry1F has recently been reported. Therefore it is important to assess the possibility of cross-resistance between Cry1F and other Cry proteins expressed in Bt maize hybrids. In this study, an F2 screen followed by subsequent selection on MON 89034 maize was used to select an S. frugiperda strain (RR) able to survive on the Bt maize event MON 89034, which expresses the Cry1A.105 and Cry2Ab2 proteins. Field-collected insects from maize expressing the Cry1F protein (event TC1507) represented most of the positive (resistance allele-containing) (iso)families found. The RR strain showed high levels of resistance to Cry1F, which apparently also conferred high levels of cross resistance to Cry1A.105 and Cry1Ab, but had only low-level (10-fold) resistance to Cry2Ab2. Life history studies to investigate fitness costs associated with the resistance in RR strain revealed only small reductions in reproductive rate when compared to susceptible and heterozygous strains, but the RR strain produced 32.2% and 28.4% fewer females from each female relative to the SS and RS (pooled) strains, respectively. Consistent with the lack of significant resistance to Cry2Ab2, MON 89034 maize in combination with appropriate management practices continues to provide effective control of S. frugiperda in Brazil. Nevertheless, the occurrence of Cry1F resistance in S. frugiperda across Brazil, and the cross-resistance to Cry1Ab and Cry1A.105

  12. Comparative Transcriptional Profiling and Preliminary Study on Heterosis Mechanism of Super-Hybrid Rice

    PubMed Central

    Song, Gui-Sheng; Zhai, Hong-Li; Peng, Yong-Gang; Zhang, Lei; Wei, Gang; Chen, Xiao-Ying; Xiao, Yu-Guo; Wang, Lili; Wu, Bin; Zhang, Yu; Feng, Xiu-Jing; Gong, Wan-Kui; Liu, Yao; Yin, Zhi-Jie; Wang, Feng; Liu, Guo-Zhen; Xu, Hong-Lin; Wei, Xiao-Li; Zhao, Xiao-Ling; Ouwerkerk, Pieter B.F.; Hankemeier, Thomas; Reijmers, Theo; van der Heijden, Rob; Wang, Mei; van der Greef, Jan; Zhu, Zhen

    2010-01-01

    Heterosis is a biological phenomenon whereby the offspring from two parents show improved and superior performance than either inbred parental lines. Hybrid rice is one of the most successful apotheoses in crops utilizing heterosis. Transcriptional profiling of F1 super-hybrid rice Liangyou-2186 and its parents by serial analysis of gene expression (SAGE) revealed 1183 differentially expressed genes (DGs), among which DGs were found significantly enriched in pathways such as photosynthesis and carbon-fixation, and most of the key genes involved in the carbon-fixation pathway exhibited up-regulated expression in F1 hybrid rice. Moreover, increased catabolic activity of corresponding enzymes and photosynthetic efficiency were also detected, which combined to indicate that carbon fixation is enhanced in F1 hybrid, and might probably be associated with the yield vigor and heterosis in super-hybrid rice. By correlating DGs with yield-related quantitative trait loci (QTL), a potential relationship between differential gene expression and phenotypic changes was also found. In addition, a regulatory network involving circadian-rhythms and light signaling pathways was also found, as previously reported in Arabidopsis, which suggest that such a network might also be related with heterosis in hybrid rice. Altogether, the present study provides another view for understanding the molecular mechanism underlying heterosis in rice. PMID:20729474

  13. Investigation of the 2f1-f2 and 2f2-f1 distortion product otoacoustic emissions using a computational model of the gerbil ear.

    PubMed

    Wen, Haiqi; Bowling, Thomas; Meaud, Julien

    2018-05-19

    In this work, a three-dimensional computational model of the gerbil ear is used to investigate the generation of the 2f 1 -f 2 and 2f 2 -f 1 distortion product otoacoustic emissions (DPOAEs). In order to predict both the distortion and reflection sources, cochlear roughness is modeled by introducing random inhomogeneities in the outer hair cell properties. The model was used to simulate the generation of DPOAEs in response to a two-tone stimulus for various primary stimulus levels and frequency ratios. As in published experiments, the 2f 1 -f 2 DPOAEs are mostly dominated by the distortion component while the 2f 2 -f 1 DPOAEs are dominated by the reflection component; furthermore, the influence of the levels and frequency ratio of the primaries are consistent with measurements. Analysis of the intracochlear response shows that the distortion component has the highest magnitude at all longitudinal locations for the 2f 1 -f 2 distortion product (DP) while the distortion component only dominates close to the DP best place in the case of the 2f 2 -f 1 DP. Decomposition of the intracochlear DPs into forward and reverse waves demonstrates that the 2f 1 -f 2 DP generates reverse waves for both the distortion and reflection components; however, a reverse wave is only generated for the reflection component in the case of the 2f 2 -f 1 DP. As in experiments in the gerbil, the group delay of the reflection component of the DPOAE is between 1× and 2× the forward group delay, which is consistent with the propagation of DP towards the stapes as slow reverse waves. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Molecular evidence for asymmetric hybridization in three closely related sympatric species

    PubMed Central

    Zhang, Ning-Ning; Yu, Jiao-Jun; Wang, Yue-Hua; Gong, Xun

    2018-01-01

    Abstract Natural hybridization is common in plants and results in different evolutionary consequences to hybridizing species. Pre- and post-zygotic reproductive isolating barriers can impede hybridization between closely related species to maintain their species integrity. In Northwest Yunnan, three Ligularia species (Ligularia cyathiceps, L. duciformis and L. yunnanensis) and four types of morphologically intermediate individuals were discovered growing together in an area subject to human disturbance. In this study, we used three low-copy nuclear loci to test the natural hybridization hypothesis and the hybridization direction was ascertained by three chloroplast DNA fragments. The results indicated there were two hybridization groups at the study site, L. cyathiceps × L. duciformis and L. duciformis × L. yunnanensis, and two types of morphologically intermediate individuals were produced by L. cyathiceps and L. duciformis, and another two types were produced by L. duciformis and L. yunnanensis, while no hybrids between L. cyathiceps and L. yunnanensis were observed. Both hybridizing groups showed bidirectional but asymmetric hybridization and the factors influencing the symmetry are discussed. Most hybrids produced by the two hybridization groups seemed to be F1 generation. Hybrids with different morphologies within the same hybridization group showed similar genetic components. The results suggest that although human disturbance may promote natural hybridization among the three Ligularia species bringing them together, hybrids are limited to F1s and therefore species boundaries might be maintained. PMID:29492242

  15. Hybrid External Fixation for Arbeitsgemeinschaft für Osteosynthesefragen (AO) 43-C Tibial Plafond Fractures.

    PubMed

    Abd-Almageed, Emad; Marwan, Yousef; Esmaeel, Ali; Mallur, Amarnath; El-Alfy, Barakat

    2015-01-01

    Arbeitsgemeinschaft für Osteosynthesefragen (AO) type 43-C tibial plafond/pilon fractures represent a challenge for the treating orthopedic surgeon. We assessed the outcomes of using hybrid external fixation for this fracture type. The present prospective cohort study was started in August 2009 and ended by July 2012. Thirty consecutive patients (mean age 37.4 ± 10.7 years) with a type C tibial plafond fracture who had presented to our tertiary care orthopedic hospital were included. Motor vehicle accidents and fall from height were the cause of the fracture in 14 (46.7%) and 13 (43.3%) patients, respectively. A type C3 fracture was present in 25 patients (83.3%), and type C1 and C2 fractures were present in 2 (6.7%) and 3 (10.0%) patients, respectively. Nine fractures (30.0%) were open. Hybrid external fixation was used for all fractures. All fractures were united; clinical healing was achieved by a mean of 18.1 ± 2.2 weeks postoperatively and radiologic healing at a mean of 18.9 ± 1.9 weeks. The fixator was removed at a mean of 20.4 ± 2.0 weeks postoperatively. At a mean follow-up point of 13.4 ± 2.6 months, the mean modified Mazur ankle score was 84.6 ± 10.4. It was not associated with wound classification (p = .256). The most commonly seen complication was ankle osteoarthritis (17 patients; 56.7%); however, it was mild in >50.0% of the affected patients. In conclusion, using hybrid external fixation for type C tibial plafond fractures resulted in good outcomes. However, this should be investigated further in studies with a higher level of evidence. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Sequenced RAPD markers to detect hybridization in the barbary partridge (Alectoris barbara, Phasianidae).

    PubMed

    Barbanera, Filippo; Guerrini, Monica; Bertoncini, Franco; Cappelli, Fabio; Muzzeddu, Marco; Dini, Fernando

    2011-01-01

    In the Alectoris partridges (Phasianidae), hybridization occurs occasionally as a result of the natural breakdown of isolating mechanisms but more frequently as a result of human activity. No genetic record of hybridization is known for the barbary partridge (A. barbara). This species is distributed mostly in North Africa and, in Europe, on the island of Sardinia (Italy) and on Gibraltar. The risk of hybridization between barbary and red-legged partridge (A. rufa: Iberian Peninsula, France, Italy) is high in Sardinia and in Spain. We developed two random amplified polymorphic DNA (RAPD) markers to detect A. barbara × A. rufa hybrid partridges. We tested them on 125 experimental hybrids, sequenced the relative species-specific bands and found that the bands and their corresponding sequences were reliably transmitted through a number of generations (F1, F2, F3, BC1, BC2). Our markers represent a highly valuable tool for the preservation of the A. barbara genome from the pressing threat of A. rufa pollution. © 2010 Blackwell Publishing Ltd.

  17. Three-Dimensional Hierarchical NixCo1-xO/NiyCo2-yP@C Hybrids on Nickel Foam for Excellent Supercapacitors.

    PubMed

    Shao, Yubo; Zhao, Yongqing; Li, Hua; Xu, Cailing

    2016-12-28

    Active materials and special structures of the electrode have decisive influence on the electrochemical properties of supercapacitors. Herein, three-dimensional (3D) hierarchical Ni x Co 1-x O/Ni y Co 2-y P@C (denoted as NiCoOP@C) hybrids have been successfully prepared by a phosphorization treatment of hierarchical Ni x Co 1-x O@C grown on nickel foam. The resulting NiCoOP@C hybrids exhibit an outstanding specific capacitance and cycle performance because they couple the merits of the superior cycling stability of Ni x Co 1-x O, the high specific capacitance of Ni y Co 2-y P, the mechanical stability of carbon layer, and the 3D hierarchical structure. The specific capacitance of 2638 F g -1 can be obtained at the current density of 1 A g -1 , and even at the current density of 20 A g -1 , the NiCoOP@C electrode still possesses a specific capacitance of 1144 F g -1 . After 3000 cycles at 10 A g -1 , 84% of the initial specific capacitance is still remained. In addition, an asymmetric ultracapacitor (ASC) is assembled through using NiCoOP@C hybrids as anode and activated carbon as cathode. The as-prepared ASC obtains a maximum energy density of 39.4 Wh kg -1 at a power density of 394 W kg -1 and still holds 21 Wh kg -1 at 7500 W kg -1 .

  18. Photographic evidence of interspecies mating in geckos of the Lepidodactylus lugubris unisexual-bisexual complex (Squamata: Gekkonidae)

    USGS Publications Warehouse

    Buden, Donald W.; Cianchini, Carlos; Taborosi, Danko; Fisher, Robert N.; Bauer, Aaron; Ineich, Ivan

    2014-01-01

    An interspecies mating between unisexual Lepidodactylus lugubris and a male of the bisexual Lepidodactylus moestus was photographed by Carlos Cianchini on Kosrae [Island], FSM, at 18:15 h on 22 August 2013 (Figure 1). The mating pair was on a window frame inside a house at Pukusruk Wan village (05°21'01" N, 163°00'41" E, elev. 28 m a.s.l.) on the northeastern side of the island. This is the first direct evidence of mating between these two species.

  19. A Synthesis of Hybrid RANS/LES CFD Results for F-16XL Aircraft Aerodynamics

    NASA Technical Reports Server (NTRS)

    Luckring, James M.; Park, Michael A.; Hitzel, Stephan M.; Jirasek, Adam; Lofthouse, Andrew J.; Morton, Scott A.; McDaniel, David R.; Rizzi, Arthur M.

    2015-01-01

    A synthesis is presented of recent numerical predictions for the F-16XL aircraft flow fields and aerodynamics. The computational results were all performed with hybrid RANS/LES formulations, with an emphasis on unsteady flows and subsequent aerodynamics, and results from five computational methods are included. The work was focused on one particular low-speed, high angle-of-attack flight test condition, and comparisons against flight-test data are included. This work represents the third coordinated effort using the F-16XL aircraft, and a unique flight-test data set, to advance our knowledge of slender airframe aerodynamics as well as our capability for predicting these aerodynamics with advanced CFD formulations. The prior efforts were identified as Cranked Arrow Wing Aerodynamics Project International, with the acronyms CAWAPI and CAWAPI-2. All information in this paper is in the public domain.

  20. Cloning of an endangered species (Bos gaurus) using interspecies nuclear transfer.

    PubMed

    Lanza, R P; Cibelli, J B; Diaz, F; Moraes, C T; Farin, P W; Farin, C E; Hammer, C J; West, M D; Damiani, P

    2000-01-01

    Approximately 100 species become extinct a day. Despite increasing interest in using cloning to rescue endangered species, successful interspecies nuclear transfer has not been previously described, and only a few reports of in vitro embryo formation exist. Here we show that interspecies nuclear transfer can be used to clone an endangered species with normal karyotypic and phenotypic development through implantation and the late stages of fetal growth. Somatic cells from a gaur bull (Bos gaurus), a large wild ox on the verge of extinction, (Species Survival Plan < 100 animals) were electrofused with enucleated oocytes from domestic cows. Twelve percent of the reconstructed oocytes developed to the blastocyst stage, and 18% of these embryos developed to the fetal stage when transferred to surrogate mothers. Three of the fetuses were electively removed at days 46 to 54 of gestation, and two continued gestation longer than 180 (ongoing) and 200 days, respectively. Microsatellite marker and cytogenetic analyses confirmed that the nuclear genome of the cloned animals was gaurus in origin. The gaur nuclei were shown to direct normal fetal development, with differentiation into complex tissue and organs, even though the mitochondrial DNA (mtDNA) within all the tissue types evaluated was derived exclusively from the recipient bovine oocytes. These results suggest that somatic cell cloning methods could be used to restore endangered, or even extinct, species and populations.

  1. The responses of crop - wild Brassica hybrids to simulated herbivory and interspecific competition: implications for transgene introgression.

    PubMed

    Sutherland, Jamie P; Justinova, Lenka; Poppy, Guy M

    2006-01-01

    Brassica rapa grows as a wild and weedy species throughout the world and is the most likely recipient of transgenes from GM oilseed rape. For transgene introgression to occur, the critical step which must be realized, is the formation of an F1 hybrid. Concerns exist that hybrid populations could be more vigorous and competitive compared to the parental species. This study examines the effect of simulated herbivory and interspecific competition on the vegetative and reproductive performance of non-transgenic F1 hybrids and their parental lines. Several vegetative and reproductive performance measures were used to determine the effect of simulated herbivory and competition on the Brassica lines, including leaf length and biomass for herbivory and seedling height and biomass for competition. For defoliation experiments, B. rapa showed little response in terms of leaf length but B. napus and the F1 hybrid responded negatively. Brassica rapa showed elevated biomass responses, but B. napus and the hybrid demonstrated negative responses to defoliation. Defoliation at the cotyledon stage had a slight effect upon final biomass with the F1 hybrid performing significantly worse than B. napus, although seed counts were not significantly different. For the series of competition experiments, hybrids seemed to be more similar to B. rapa in terms of early seedling growth and reproductive measures. The underperformance of hybrid plants when challenged by herbivory and competition, could potentially decrease survivorship and explain the rarity of hybrids in field surveys. However, should transgene introgression occur, the dynamics of hybrids could change radically thus increasing the risk of gene flow from a transgenic oilseed rape crop to the wild recipient.

  2. Spicing Up the N Gene: F. O. Holmes and Tobacco mosaic virus Resistance in Capsicum and Nicotiana Plants.

    PubMed

    Scholthof, Karen-Beth G

    2017-02-01

    One of the seminal events in plant pathology was the discovery by Francis O. Holmes that necrotic local lesions induced on certain species of Nicotiana following rub-inoculation of Tobacco mosaic virus (TMV) was due to a specific interaction involving a dominant host gene (N). From this, Holmes had an idea that if the N gene from N. glutinosa was introgressed into susceptible tobacco, the greatly reduced titer of TMV would, by extension, prevent subsequent infection of tomato and pepper plants by field workers whose hands were contaminated with TMV from their use of chewing and smoking tobacco. The ultimate outcome has many surprising twists and turns, including Holmes' failure to obtain fertile crosses of N. glutinosa × N. tabacum after 3 years of intensive work. Progress was made with N. digluta, a rare amphidiploid that was readily crossed with N. tabacum. And, importantly, the first demonstration by Holmes of the utility of interspecies hybridization for virus resistance was made with Capsicum (pepper) species with the identification of the L gene in Tabasco pepper, that he introgressed into commercial bell pepper varieties. Holmes' findings are important as they predate Flor's gene-for-gene hypothesis, show the use of interspecies hybridization for control of plant pathogens, and the use of the local lesion as a bioassay to monitor resistance events in crop plants.

  3. [Production of interspecies hybrid of cranes by artificial insemination with frozen semen].

    PubMed

    Maksudov, G Iu; Panchenko, V G

    2002-01-01

    Studies of artificial insemination of cranes and cryoconservation of their semen have been carried out in the nursery of rare species at the Oka Biosphere Reserve for many years. The criterion of successful cryoconservation of the semen is the obtaining of fertilized eggs after artificial insemination by the thawed semen. An experiment is described on artificial insemination of females of the white-naped crane Grus vipio by the frozen-thawed semen of the Siberian white crane G. leucogeranus after one-year storage of semen in liquid nitrogen. As a result, an interspecific hybrid of cranes was obtained, which confirmed the possibility of producing a bank of cryoconserved crane semen. The use of the white-naped crane females was due to the absence of conspecific males and unavailability of Siberian white crane females. Problems of artificial insemination and cryoconservation of semen of rare crane species are discussed.

  4. 26 CFR 1.860F-1 - Qualified liquidations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Qualified liquidations. 1.860F-1 Section 1.860F-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Real Estate Investment Trusts § 1.860F-1 Qualified liquidations. A plan of...

  5. 26 CFR 1.860F-1 - Qualified liquidations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 9 2011-04-01 2011-04-01 false Qualified liquidations. 1.860F-1 Section 1.860F-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Real Estate Investment Trusts § 1.860F-1 Qualified liquidations. A plan...

  6. 26 CFR 1.860F-1 - Qualified liquidations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 9 2014-04-01 2014-04-01 false Qualified liquidations. 1.860F-1 Section 1.860F-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Real Estate Investment Trusts § 1.860F-1 Qualified liquidations. A plan...

  7. 26 CFR 1.860F-1 - Qualified liquidations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 9 2012-04-01 2012-04-01 false Qualified liquidations. 1.860F-1 Section 1.860F-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Real Estate Investment Trusts § 1.860F-1 Qualified liquidations. A plan...

  8. 26 CFR 1.860F-1 - Qualified liquidations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 9 2013-04-01 2013-04-01 false Qualified liquidations. 1.860F-1 Section 1.860F-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Real Estate Investment Trusts § 1.860F-1 Qualified liquidations. A plan...

  9. The Drosophila Juvenile Hormone Receptor Candidates Methoprene-tolerant (MET) and Germ Cell-expressed (GCE) Utilize a Conserved LIXXL Motif to Bind the FTZ-F1 Nuclear Receptor*

    PubMed Central

    Bernardo, Travis J.; Dubrovsky, Edward B.

    2012-01-01

    Juvenile hormone (JH) has been implicated in many developmental processes in holometabolous insects, but its mechanism of signaling remains controversial. We previously found that in Drosophila Schneider 2 cells, the nuclear receptor FTZ-F1 is required for activation of the E75A gene by JH. Here, we utilized insect two-hybrid assays to show that FTZ-F1 interacts with two JH receptor candidates, the bHLH-PAS paralogs MET and GCE, in a JH-dependent manner. These interactions are severely reduced when helix 12 of the FTZ-F1 activation function 2 (AF2) is removed, implicating AF2 as an interacting site. Through homology modeling, we found that MET and GCE possess a C-terminal α-helix featuring a conserved motif LIXXL that represents a novel nuclear receptor (NR) box. Docking simulations supported by two-hybrid experiments revealed that FTZ-F1·MET and FTZ-F1·GCE heterodimer formation involves a typical NR box-AF2 interaction but does not require the canonical charge clamp residues of FTZ-F1 and relies primarily on hydrophobic contacts, including a unique interaction with helix 4. Moreover, we identified paralog-specific features, including a secondary interaction site found only in MET. Our findings suggest that a novel NR box enables MET and GCE to interact JH-dependently with the AF2 of FTZ-F1. PMID:22249180

  10. Nonleptonic decays of B →(f1(1285 ),f1(1420 ))V in the perturbative QCD approach

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Xiao, Zhen-Jun; Zou, Zhi-Tian

    2016-12-01

    We investigate the branching ratios, the polarization fractions, the direct C P -violating asymmetries, and the relative phases in 20 nonleptonic decay modes of B →f1V within the framework of the perturbative QCD approach at leading order with f1 including two 3P1-axial-vector states f1(1285 ) and f1(1420 ) . Here, B denotes B+, B0, and Bs0 mesons and V stands for the lightest vector mesons ρ , K*, ω , and ϕ , respectively. The Bs0→f1V decays are studied theoretically for the first time in the literature. Together with the angle ϕf1≈(24-2.7+3.2)∘ extracted from the measurement through Bd /s→J /ψ f1(1285 ) modes for the f1(1285 )-f1(1420 ) mixing system, it is of great interest to find phenomenologically some modes such as the tree-dominated B+→f1ρ+ and the penguin-dominated B+,0→f1K*+,0 , Bs0→f1ϕ with large branching ratios around O (10-6) or even O (10-5), which are expected to be measurable at the LHCb and/or the Belle-II experiments in the near future. The good agreement (sharp contrast) of branching ratios and decay pattern for B+→f1ρ+ , B+,0→f1(1285 )K*+,0[B+,0→f1(1420 )K*+,0] decays between QCD factorization and perturbative QCD factorization predictions can help us to distinguish these two rather different factorization approaches via precision measurements, which would also be helpful for us in exploring the annihilation decay mechanism through its important roles for the considered B →f1V decays.

  11. Quorum Sensing Extracellular Death Peptides Enhance the Endoribonucleolytic Activities of Mycobacterium tuberculosis MazF Toxins

    PubMed Central

    Nigam, Akanksha; Kumar, Sathish

    2018-01-01

    ABSTRACT mazEF is a toxin-antitoxin module located on chromosomes of most bacteria. MazF toxins are endoribonucleases antagonized by MazE antitoxins. Previously, we characterized several quorum sensing peptides called "extracellular death factors" (EDFs). When secreted from bacterial cultures, EDFs induce interspecies cell death. EDFs also enhance the endoribonucleolytic activity of Escherichia coli MazF. Mycobacterium tuberculosis carries several mazEF modules. Among them, the endoribonucleolytic activities of MazF proteins mt-1, mt-3, and mt-6 were identified. MazF-mt6 and MazF-mt-3 cleave M. tuberculosis rRNAs. Here we report the in vitro effects of EDFs on the endoribonucleolytic activities of M. tuberculosis MazFs. Escherichia coli EDF (EcEDF) and the three Pseudomonas aeruginosa EDFs (PaEDFs) individually enhance the endoribonucleolytic activities of MazF-mt6 and MazF-mt3 and overcome the inhibitory effect of MazE-mt3 or MazE-mt6 on the endoribonucleolytic activities of the respective toxins. We propose that these EDFs can serve as a basis for a novel class of antibiotics against M. tuberculosis. PMID:29717013

  12. Trade-off between morphological convergence and opportunistic diet behavior in fish hybrid zone

    PubMed Central

    Corse, Emmanuel; Costedoat, Caroline; Pech, Nicolas; Chappaz, Rémi; Grey, Jonathan; Gilles, André

    2009-01-01

    Background The invasive Chondrostoma nasus nasus has colonized part of the distribution area of the protected endemic species Chondrostoma toxostoma toxostoma. This hybrid zone is a complex system where multiple effects such as inter-species competition, bi-directional introgression, strong environmental pressure and so on are combined. Why do sympatric Chondrostoma fish present a unidirectional change in body shape? Is this the result of inter-species interactions and/or a response to environmental effects or the result of trade-offs? Studies focusing on the understanding of a trade-off between multiple parameters are still rare. Although this has previously been done for Cichlid species flock and for Darwin finches, where mouth or beak morphology were coupled to diet and genetic identification, no similar studies have been done for a fish hybrid zone in a river. We tested the correlation between morphology (body and mouth morphology), diet (stable carbon and nitrogen isotopes) and genomic combinations in different allopatric and sympatric populations for a global data set of 1330 specimens. To separate the species interaction effect from the environmental effect in sympatry, we distinguished two data sets: the first one was obtained from a highly regulated part of the river and the second was obtained from specimens coming from the less regulated part. Results The distribution of the hybrid combinations was different in the two part of the sympatric zone, whereas all the specimens presented similar overall changes in body shape and in mouth morphology. Sympatric specimens were also characterized by a larger diet behavior variance than reference populations, characteristic of an opportunistic diet. No correlation was established between the body shape (or mouth deformation) and the stable isotope signature. Conclusion The Durance River is an untamed Mediterranean river despite the presence of numerous dams that split the river from upstream to downstream. The

  13. 26 CFR 1.267(f)-1 - Controlled groups.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 3 2013-04-01 2013-04-01 false Controlled groups. 1.267(f)-1 Section 1.267(f)-1...) INCOME TAXES (CONTINUED) Items Not Deductible § 1.267(f)-1 Controlled groups. (a) In general—(1) Purpose... transactions between members of a controlled group (intercompany sales). The purpose of this section is to...

  14. 26 CFR 1.267(f)-1 - Controlled groups.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 3 2014-04-01 2014-04-01 false Controlled groups. 1.267(f)-1 Section 1.267(f)-1...) INCOME TAXES (CONTINUED) Items Not Deductible § 1.267(f)-1 Controlled groups. (a) In general—(1) Purpose... transactions between members of a controlled group (intercompany sales). The purpose of this section is to...

  15. 26 CFR 1.267(f)-1 - Controlled groups.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 3 2012-04-01 2012-04-01 false Controlled groups. 1.267(f)-1 Section 1.267(f)-1...) INCOME TAXES (CONTINUED) Items Not Deductible § 1.267(f)-1 Controlled groups. (a) In general—(1) Purpose... transactions between members of a controlled group (intercompany sales). The purpose of this section is to...

  16. Hybrid GMR Sensor Detecting 950 pT/sqrt(Hz) at 1 Hz and Room Temperature

    PubMed Central

    Guedes, André; Macedo, Rita; Jaramillo, Gerardo; Freitas, Paulo P.; Horsley, David A.

    2018-01-01

    Advances in the magnetic sensing technology have been driven by the increasing demand for the capability of measuring ultrasensitive magnetic fields. Among other emerging applications, the detection of magnetic fields in the picotesla range is crucial for biomedical applications. In this work Picosense reports a millimeter-scale, low-power hybrid magnetoresistive-piezoelectric magnetometer with subnanotesla sensitivity at low frequency. Through an innovative noise-cancelation mechanism, the 1/f noise in the MR sensors is surpassed by the mechanical modulation of the external magnetic fields in the high frequency regime. A modulation efficiency of 13% was obtained enabling a final device’s sensitivity of ~950 pT/Hz1/2 at 1 Hz. This hybrid device proved to be capable of measuring biomagnetic signals generated in the heart in an unshielded environment. This result paves the way for the development of a portable, contactless, low-cost and low-power magnetocardiography device. PMID:29509677

  17. Multiple Origins of the Pathogenic Yeast Candida orthopsilosis by Separate Hybridizations between Two Parental Species.

    PubMed

    Schröder, Markus S; Martinez de San Vicente, Kontxi; Prandini, Tâmara H R; Hammel, Stephen; Higgins, Desmond G; Bagagli, Eduardo; Wolfe, Kenneth H; Butler, Geraldine

    2016-11-01

    Mating between different species produces hybrids that are usually asexual and stuck as diploids, but can also lead to the formation of new species. Here, we report the genome sequences of 27 isolates of the pathogenic yeast Candida orthopsilosis. We find that most isolates are diploid hybrids, products of mating between two unknown parental species (A and B) that are 5% divergent in sequence. Isolates vary greatly in the extent of homogenization between A and B, making their genomes a mosaic of highly heterozygous regions interspersed with homozygous regions. Separate phylogenetic analyses of SNPs in the A- and B-derived portions of the genome produces almost identical trees of the isolates with four major clades. However, the presence of two mutually exclusive genotype combinations at the mating type locus, and recombinant mitochondrial genomes diagnostic of inter-clade mating, shows that the species C. orthopsilosis does not have a single evolutionary origin but was created at least four times by separate interspecies hybridizations between parents A and B. Older hybrids have lost more heterozygosity. We also identify two isolates with homozygous genomes derived exclusively from parent A, which are pure non-hybrid strains. The parallel emergence of the same hybrid species from multiple independent hybridization events is common in plant evolution, but is much less documented in pathogenic fungi.

  18. 26 CFR 1.691(f)-1 - Cross reference.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Cross reference. 1.691(f)-1 Section 1.691(f)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Income in Respect of Decedents § 1.691(f)-1 Cross reference. See section 753 and the...

  19. 26 CFR 1.415(f)-1 - Aggregating plans.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Aggregating plans. 1.415(f)-1 Section 1.415(f)-1...) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.415(f)-1 Aggregating plans. (a) In general. Except as provided in paragraph (g) of this section (regarding multiemployer plans), and taking...

  20. Identification, cloning, and characterization of a major cat flea salivary allergen (Cte f 1).

    PubMed

    McDermott, M J; Weber, E; Hunter, S; Stedman, K E; Best, E; Frank, G R; Wang, R; Escudero, J; Kuner, J; McCall, C

    2000-05-01

    An 18 kDa protein isolated from saliva of the cat flea, Ctenocephalides felis, elicits a positive intradermal skin test (IDST) in 100 and 80% of experimental and clinical flea allergic dogs, respectively. Using solid-phase enzyme-linked immuno assay (ELISA), this protein detected IgE in 100 and 80% of experimental and clinical flea allergic dogs, respectively. A cDNA (pFSI) encoding a full-length Cte f 1 protein was isolated from a C. felis salivary gland cDNA library, using a combination of PCR and hybridization screening. This cDNA is 658 bp in length, and contains an open reading frame of 528 bp. The open reading frame encodes a protein of 176 amino acids, consisting of an 18 amino acid signal sequence and a 158 amino acid mature protein. The calculated molecular weight and pI of the mature protein are 18106 Da and 9.3, respectively. The protein, named Cte f 1, is the first novel major allergen described for canine flea allergy. Recombinant Cte f 1 (rCte f 1) was expressed in Escherichia coli, Pichia pastoris and baculovirus infected Trichoplusia ni cells. Approximately, 90% of the rCte f 1 expressed in E. coli accumulated in insoluble inclusion bodies, which could be refolded to a soluble mixture of disulfide isomers with partial IgE binding activity. Small quantities of an apparently correctly refolded form of rCte f 1, which had IgE binding activity equal to the native antigen, was isolated from the soluble fraction of E. coli cells. However, P. pastoris and baculovirus infected insect cells expressed and secreted a fully processed, correctly refolded and fully active form of rCte f 1. Mass spectrometry analysis of the active forms of rCte f 1confirmed that eight intact disulfide bonds were present, matching the number observed in the native allergen. The relative ability of rCte f 1 to bind IgE in the serum of flea allergic animals, produced in these three expression systems, matched that of the native allergen. Competition ELISA demonstrated that

  1. A high-resolution cat radiation hybrid and integrated FISH mapping resource for phylogenomic studies across Felidae.

    PubMed

    Davis, Brian W; Raudsepp, Terje; Pearks Wilkerson, Alison J; Agarwala, Richa; Schäffer, Alejandro A; Houck, Marlys; Chowdhary, Bhanu P; Murphy, William J

    2009-04-01

    We describe the construction of a high-resolution radiation hybrid (RH) map of the domestic cat genome, which includes 2662 markers, translating to an estimated average intermarker distance of 939 kilobases (kb). Targeted marker selection utilized the recent feline 1.9x genome assembly, concentrating on regions of low marker density on feline autosomes and the X chromosome, in addition to regions flanking interspecies chromosomal breakpoints. Average gap (breakpoint) size between cat-human ordered conserved segments is less than 900 kb. The map was used for a fine-scale comparison of conserved syntenic blocks with the human and canine genomes. Corroborative fluorescence in situ hybridization (FISH) data were generated using 129 domestic cat BAC clones as probes, providing independent confirmation of the long-range correctness of the map. Cross-species hybridization of BAC probes on divergent felids from the genera Profelis (serval) and Panthera (snow leopard) provides further evidence for karyotypic conservation within felids, and demonstrates the utility of such probes for future studies of chromosome evolution within the cat family and in related carnivores. The integrated map constitutes a comprehensive framework for identifying genes controlling feline phenotypes of interest, and to aid in assembly of a higher coverage feline genome sequence.

  2. A High-Resolution Cat Radiation Hybrid and Integrated FISH Mapping Resource for Phylogenomic Studies across Felidae

    PubMed Central

    Davis, Brian W.; Raudsepp, Terje; Wilkerson, Alison J. Pearks; Agarwala, Richa; Schäffer, Alejandro A.; Houck, Marlys; Ryder, Oliver A.; Chowdhdary, Bhanu P.; Murphy, William J.

    2008-01-01

    We describe the construction of a high-resolution radiation hybrid (RH) map of the domestic cat genome, which includes 2,662 markers, translating to an estimated average intermarker distance of 939 kilobases (Kb). Targeted marker selection utilized the recent feline 1.9x genome assembly, concentrating on regions of low marker density on feline autosomes and the X chromosome, in addition to regions flanking interspecies chromosomal breakpoints. Average gap (breakpoint) size between cat-human ordered conserved segments is less than 900 Kb. The map was used for a fine-scale comparison of conserved syntenic blocks with the human and canine genomes. Corroborative fluorescence in situ hybridization (FISH) data were generated using 129 domestic cat BAC-clones as probes, providing independent confirmation of the long-range correctness of the map. Cross-species hybridization of BAC probes on divergent felids from the genera Profelis (serval) and Panthera (snow leopard) provides further evidence for karyotypic conservation within felids, and demonstrates the utility of such probes for future studies of chromosome evolution within the cat family and in related carnivores. The integrated map constitutes a comprehensive framework for identifying genes controlling feline phenotypes of interest, and to aid in assembly of a higher coverage feline genome sequence. PMID:18951970

  3. Hybrid embryos produced by transferring panda or cat somatic nuclei into rabbit MII oocytes can develop to blastocyst in vitro.

    PubMed

    Wen, Duan-Cheng; Bi, Chun-Ming; Xu, Ying; Yang, Cai-Xia; Zhu, Zi-Yu; Sun, Qing-Yuan; Chen, Da-Yuan

    2005-08-01

    The developmental potential of hybrid embryos produced by transferring panda or cat fibroblasts into nucleated rabbit oocytes was assessed. Both the panda-rabbit and the cat-rabbit hybrid embryos were able to form blastocysts in vitro. However, the rates of attaining the two-cell, four-cell, eight-cell, morula, or blastocyst stages for panda-rabbit hybrids were significantly greater than those of cat-rabbit hybrids (P<0.05). Transferring the rabbit fibroblasts into nucleated rabbit oocytes, 31.0% of the blastocyst rate was obtained, which was significantly higher than that of both the panda-rabbit and the cat-rabbit hybrid embryos (P<0.05). Whether or not the second polar body (PB2) was extruded from the one-cell hybrid embryos (both panda-rabbit and cat-rabbit hybrids) significantly affected their developmental capacity. Embryos without an extruded PB2 showed a higher capacity to develop into blastocysts (panda-rabbit: 19.2%; cat-rabbit: 4.3%), while embryos with extruded PB2 could only develop to the morula stage. The hybrid embryos formed pronucleus-like structures (PN) in 2-4 hr after activation, and the number of PN in one-cell embryos varied from one to five. Tracking of the nucleus in the egg after fusion revealed that the somatic nucleus could approach and aggregate with the oocyte nucleus spontaneously. Chromosome analysis of the panda-rabbit blastocysts showed that the karyotype of the hybrid embryos (2n=86) consisted of chromosomes from both the panda (2n=42) and the rabbit (2n=44). The results demonstrate that (1) it is possible to produce genetic hybrid embryos by interspecies nuclear transfer; (2) the developmental potential of the hybrid embryos is highly correlated to the donor nucleus species; and (3) the hybrid genome is able to support the complete preimplantation embryonic development of the hybrids. Copyright (c) 2005 Wiley-Liss, Inc.

  4. Hybridization of powdery mildew strains gives rise to pathogens on novel agricultural crop species.

    PubMed

    Menardo, Fabrizio; Praz, Coraline R; Wyder, Stefan; Ben-David, Roi; Bourras, Salim; Matsumae, Hiromi; McNally, Kaitlin E; Parlange, Francis; Riba, Andrea; Roffler, Stefan; Schaefer, Luisa K; Shimizu, Kentaro K; Valenti, Luca; Zbinden, Helen; Wicker, Thomas; Keller, Beat

    2016-02-01

    Throughout the history of agriculture, many new crop species (polyploids or artificial hybrids) have been introduced to diversify products or to increase yield. However, little is known about how these new crops influence the evolution of new pathogens and diseases. Triticale is an artificial hybrid of wheat and rye, and it was resistant to the fungal pathogen powdery mildew (Blumeria graminis) until 2001 (refs. 1,2,3). We sequenced and compared the genomes of 46 powdery mildew isolates covering several formae speciales. We found that B. graminis f. sp. triticale, which grows on triticale and wheat, is a hybrid between wheat powdery mildew (B. graminis f. sp. tritici) and mildew specialized on rye (B. graminis f. sp. secalis). Our data show that the hybrid of the two mildews specialized on two different hosts can infect the hybrid plant species originating from those two hosts. We conclude that hybridization between mildews specialized on different species is a mechanism of adaptation to new crops introduced by agriculture.

  5. Using Web-based Interspecies Correlation Estimation (Web-ICE) models as a tool for acute toxicity prediction

    EPA Science Inventory

    In order to assess risk of contaminants to taxa with limited or no toxicity data available, Interspecies Correlation Estimation (ICE) models have been developed by the U.S. Environmental Protection Agency to extrapolate contaminant sensitivity predictions based on data from commo...

  6. Two dominant loci determine resistance to Phomopsis cane lesions in F1 families of hybrid grapevines

    USDA-ARS?s Scientific Manuscript database

    Phomopsis cane and leaf spot, caused by the hemibiotrophic fungus Diaporthe ampelina (syn = Phomopsis viticola), produces lesions on grapevine stems and berries, reducing productivity. Host resistance was studied on three F1 families derived from crosses involving ‘Horizon’, Illinois 547-1, Vitis ci...

  7. Charmless hadronic B →(f1(1285 ),f1(1420 ))P decays in the perturbative QCD approach

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Xiao, Zhen-Jun; Li, Jing-Wu; Zou, Zhi-Tian

    2015-01-01

    We study 20 charmless hadronic B →f1P decays in the perturbative QCD (pQCD) formalism with B denoting Bu, Bd, and Bs mesons; P standing for the light pseudoscalar mesons; and f1 representing axial-vector mesons f1(1285 ) and f1(1420 ) that result from a mixing of quark-flavor f1 q[u/u ¯ +d d ¯ √{2 } ] and f1 s[s s ¯ ] states with the angle ϕf1.The estimations of C P -averaged branching ratios and C P asymmetries of the considered B →f1P decays, in which the Bs→f1P modes are investigated for the first time, are presented in the pQCD approach with ϕf 1˜24 ° from recently measured Bd /s→J /ψ f1(1285 ) decays. It is found that (a) the tree (penguin) dominant B+→f1π+(K+) decays with large branching ratios [O (10-6) ] and large direct C P violations (around 14%-28% in magnitude) simultaneously are believed to be clearly measurable at the LHCb and Belle II experiments; (b) the Bd→f1KS0 and Bs→f1(η ,η') decays with nearly pure penguin contributions and safely negligible tree pollution also have large decay rates in the order of 10-6- 10-5 , which can be confronted with the experimental measurements in the near future; (c) as the alternative channels, the B+→f1(π+,K+) and Bd→f1KS0 decays have the supplementary power in providing more effective constraints on the Cabibbo-Kobayashi-Maskawa weak phases α , γ , and β , correspondingly, which are explicitly analyzed through the large decay rates and the direct and mixing-induced C P asymmetries in the pQCD approach and are expected to be stringently examined by the measurements with high precision; (d) the weak annihilation amplitudes play important roles in the B+→f1(1420 )K+ , Bd→f1(1420 )KS0 , Bs→f1(1420 )η' decays, and so on, which would offer more evidence, once they are confirmed by the experiments, to identify the soft-collinear effective theory and the pQCD approach on the evaluations of annihilation diagrams and to help further understand the annihilation mechanism in the heavy

  8. Successful cloning of coyotes through interspecies somatic cell nuclear transfer using domestic dog oocytes.

    PubMed

    Hwang, Insung; Jeong, Yeon Woo; Kim, Joung Joo; Lee, Hyo Jeong; Kang, Mina; Park, Kang Bae; Park, Jung Hwan; Kim, Yeun Wook; Kim, Woo Tae; Shin, Taeyoung; Hyun, Sang Hwan; Jeung, Eui-Bae; Hwang, Woo Suk

    2013-01-01

    Interspecies somatic cell nuclear transfer (iSCNT) is an emerging assisted reproductive technology (ART) for preserving Nature's diversity. The scarcity of oocytes from some species makes utilisation of readily available oocytes inevitable. In the present study, we describe the successful cloning of coyotes (Canis latrans) through iSCNT using oocytes from domestic dogs (Canis lupus familiaris or dingo). Transfer of 320 interspecies-reconstructed embryos into 22 domestic dog recipients resulted in six pregnancies, from which eight viable offspring were delivered. Fusion rate and cloning efficiency during iSCNT cloning of coyotes were not significantly different from those observed during intraspecies cloning of domestic dogs. Using neonatal fibroblasts as donor cells significantly improved the cloning efficiency compared with cloning using adult fibroblast donor cells (P<0.05). The use of domestic dog oocytes in the cloning of coyotes in the present study holds promise for cloning other endangered species in the Canidae family using similar techniques. However, there are still limitations of the iSCNT technology, as demonstrated by births of morphologically abnormal coyotes and the clones' inheritance of maternal domestic dog mitochondrial DNA.

  9. The chemo-mechanical coupled model for F(1)F(0)-motor.

    PubMed

    Xu, Lizhong; Liu, Fang

    2012-04-01

    F(1)F(0)-motor (ATP synthase) is the universal enzyme in biological energy conversion that is present in the membranes of mitochondria, chloroplasts and bacteria. It uses the energy of the proton gradient across the membrane to synthesize ATP. Previous theory and model about rotation of the ATP synthase is reviewed, then a novel chemo-mechanical coupled model for rotation of the F(1)F(0)-motor is proposed. In the model, more events are considered simultaneously that includes the movement of F(1), the movement of F(0), reactions at F(1) and reactions at F(0). Using the model, the possible substep modes of the rotation for F(1)F(0) are predicted, the dependence of the motor efficiency and its rotation rate on the rigidity of the γ shaft is investigated. We conclude that the γ shaft has a large rotation rate for a limited driving potential because two ends of the γ shaft can rotate alternately for its flexibility. The flexibility also makes the efficiency of F(1)F(0) drop because elastic twisting deformation power is needed during alternate rotation of the γ shaft at two ends. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Polyploidy Enhances F1 Pollen Sterility Loci Interactions That Increase Meiosis Abnormalities and Pollen Sterility in Autotetraploid Rice1[OPEN

    PubMed Central

    Wu, Jinwen; Chen, Lin; Chen, Zhixiong; Wang, Lan; Lu, Yonggen

    2015-01-01

    Intersubspecific autotetraploid rice (Oryza sativa ssp. indica × japonica) hybrids have greater biological and yield potentials than diploid rice. However, the low fertility of intersubspecific autotetraploid hybrids, which is largely caused by high pollen abortion rates, limits their commercial utility. To decipher the cytological and molecular mechanisms underlying allelic interactions in autotetraploid rice, we developed an autotetraploid rice hybrid that was heterozygous (SiSj) at F1 pollen sterility loci (Sa, Sb, and Sc) using near-isogenic lines. Cytological studies showed that the autotetraploid had higher percentages (>30%) of abnormal chromosome behavior and aberrant meiocytes (>50%) during meiosis than did the diploid rice hybrid control. Analysis of gene expression profiles revealed 1,888 genes that were differentially expressed between the autotetraploid and diploid hybrid lines at the meiotic stage, among which 889 and 999 were up- and down-regulated, respectively. Of the 999 down-regulated genes, 940 were associated with the combined effect of polyploidy and pollen sterility loci interactions (IPE). Gene Ontology enrichment analysis identified a prominent functional gene class consisting of seven genes related to photosystem I (Gene Ontology 0009522). Moreover, 55 meiosis-related or meiosis stage-specific genes were associated with IPE in autotetraploid rice, including Os02g0497500, which encodes a DNA repair-recombination protein, and Os02g0490000, which encodes a component of the ubiquitin-proteasome pathway. These results suggest that polyploidy enhances epistatic interactions between alleles of pollen sterility loci, thereby altering the expression profiles of important meiosis-related or meiosis stage-specific genes and resulting in high pollen sterility. PMID:26511913

  11. Genome-scan analysis for quantitative trait loci in an F2 tilapia hybrid.

    PubMed

    Cnaani, A; Zilberman, N; Tinman, S; Hulata, G; Ron, M

    2004-09-01

    We searched for genetic linkage between DNA markers and quantitative trait loci (QTLs) for innate immunity, response to stress, biochemical parameters of blood, and fish size in an F2 population derived from an interspecific tilapia hybrid (Oreochromis mossambicusx O. aureus). A family of 114 fish was scanned for 40 polymorphic microsatellite DNA markers and two polymorphic genes, covering approximately 80% of the tilapia genome. These fish had previously been phenotyped for seven immune-response traits and six blood parameters. Critical values for significance were P <0.05 with the false discovery rate (FDR) controlled at 40%. The genome-scan analysis resulted in 35 significant marker-trait associations, involving 26 markers in 16 linkage groups. In a second experiment, nine markers were re-sampled in a second family of 79 fish of the same species hybrid. Seven markers (GM180, GM553, MHC-I, UNH848, UNH868, UNH898 and UNH925) in five linkage groups (LG 1, 3, 4, 22 and 23) were associated with stress response traits. An additional six markers (GM47, GM552, UNH208, UNH881, UNH952, UNH998) in five linkage groups (LG 4, 16, 19, 20 and 23) were verified for their associations with immune response traits, by linkage to several different traits. The portion of variance explained by each QTL was 11% on average, with a maximum of 29%. The average additive effect of QTLs was 0.2 standard deviation units of stress response traits and fish size, with a maximum of 0.33. In three linkage groups (LG 1, 3 and 23) markers were associated with stress response, body weight and sex determination, confirming the location of QTLs reported by several other studies.

  12. Compact setup for the production of {sup 87}Rb |F = 2, m{sub F} = + 2〉 Bose-Einstein condensates in a hybrid trap

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

    Nolli, Raffaele; Venturelli, Michela; Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk

    We present a compact experimental apparatus for Bose-Einstein condensation of {sup 87}Rb in the |F  =  2, m{sub F} = + 2〉 state. A pre-cooled atomic beam of {sup 87}Rb is obtained by using an unbalanced magneto-optical trap, allowing controlled transfer of trapped atoms from the first vacuum chamber to the science chamber. Here, atoms are transferred to a hybrid trap, as produced by overlapping a magnetic quadrupole trap with a far-detuned optical trap with crossed beam configuration, where forced radiofrequency evaporation is realized. The final evaporation leading to Bose-Einstein condensation is then performed by exponentially lowering the optical trapmore » depth. Control and stabilization systems of the optical trap beams are discussed in detail. The setup reliably produces a pure condensate in the |F = 2, m{sub F} = + 2〉 state in 50 s, which includes 33 s loading of the science magneto-optical trap and 17 s forced evaporation.« less

  13. Engineering three-dimensional hybrid supercapacitors and microsupercapacitors for high-performance integrated energy storage.

    PubMed

    El-Kady, Maher F; Ihns, Melanie; Li, Mengping; Hwang, Jee Youn; Mousavi, Mir F; Chaney, Lindsay; Lech, Andrew T; Kaner, Richard B

    2015-04-07

    Supercapacitors now play an important role in the progress of hybrid and electric vehicles, consumer electronics, and military and space applications. There is a growing demand in developing hybrid supercapacitor systems to overcome the energy density limitations of the current generation of carbon-based supercapacitors. Here, we demonstrate 3D high-performance hybrid supercapacitors and microsupercapacitors based on graphene and MnO2 by rationally designing the electrode microstructure and combining active materials with electrolytes that operate at high voltages. This results in hybrid electrodes with ultrahigh volumetric capacitance of over 1,100 F/cm(3). This corresponds to a specific capacitance of the constituent MnO2 of 1,145 F/g, which is close to the theoretical value of 1,380 F/g. The energy density of the full device varies between 22 and 42 Wh/l depending on the device configuration, which is superior to those of commercially available double-layer supercapacitors, pseudocapacitors, lithium-ion capacitors, and hybrid supercapacitors tested under the same conditions and is comparable to that of lead acid batteries. These hybrid supercapacitors use aqueous electrolytes and are assembled in air without the need for expensive "dry rooms" required for building today's supercapacitors. Furthermore, we demonstrate a simple technique for the fabrication of supercapacitor arrays for high-voltage applications. These arrays can be integrated with solar cells for efficient energy harvesting and storage systems.

  14. Genetic analysis of a hybrid sterility gene that causes both pollen and embryo sac sterility in hybrids between Oryza sativa L. and Oryza longistaminata.

    PubMed

    Chen, H; Zhao, Z; Liu, L; Kong, W; Lin, Y; You, S; Bai, W; Xiao, Y; Zheng, H; Jiang, L; Li, J; Zhou, J; Tao, D; Wan, J

    2017-09-01

    Oryza longistaminata originates from African wild rice and contains valuable traits conferring tolerance to biotic and abiotic stress. However, interspecific crosses between O. longistaminata and Oryza sativa cultivars are hindered by reproductive barriers. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL) using indica variety RD23 as the recipient parent and O. longistaminata as the donor parent. Both pollen and embryo sac semi-sterility were observed in F 1 hybrids between RD23 and NIL. Cytological analysis demonstrated that pollen abortion in F 1 hybrids occurred at the early bi-nucleate stage due to a failure of the first mitosis in microspores. Partial embryo sacs in the F 1 hybrids were defective during the functional megaspore formation stage. Most notably, nearly half of the male or female gametes were aborted in heterozygotes S40 i S40 l , regardless of their genotypes. Thus, S40 was indicated as a one-locus sporophytic sterility gene controlling both male and female fertility in hybrids between RD23 and O. longistaminata. A population of 16 802 plants derived from the hybrid RD23/NIL-S40 was developed to fine-map S40. Finally, the S40 locus was delimited to an 80-kb region on the short arm of chromosome 1 in terms with reference sequences of cv. 93-11. Eight open reading frames (ORFs) were localized in this region. On the basis of gene expression and genomic sequence analysis, ORF5 and ORF8 were identified as candidate genes for the S40 locus. These results are helpful in cloning the S40 gene and marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

  15. [In vitro development and chimeric efficiency of mouse-porcine interspecies chimeric embryos in different culture systems].

    PubMed

    Wang, Ying; Ren, Jilong; Song, Yuran; Hai, Tang; Zhou, Qi; Liu, Zhonghua

    2016-07-25

    With the advancements of stem cells and regenerative medicine, interspecies chimera has become a hot topic and will pave a new way of providing donor sources in organ transplantation. However, the interspecies chimera is confronted with a number of scientific questions and technical obstacles, including selections of appropriate embryonic stage and appropriate culture medium; those factors will deeply influence the developmental balance between donor cells and receptor embryos. Due to its relatively rapid reproductive cycle and similar organ size to human's, porcine is a very potential donor candidate to study these questions. To compare the development and chimeric efficiency of interspecies embryos, we tested and evaluated three different culture systems, PZM-3 (Porcine zygotic medium), culture medium for iPSCs (N2B27) and 3.5 h of N2B27 before PZM-3 (N2B27(3.5 h)), and two different embryonic stages, 8-cell and blastocyst in mouse-porcine chimeric embryos using parthenogenetically activated porcine embryos and mouse induced pluripotent stem cells (miPS). The results showed that, PZM-3 was beneficial for both development of chimeric embryos and miPSCs proliferation in porcine embryos in the 8-cell injection group. After early blastocyst injection, the chimeric efficiency did not appear significantly different among the three culture systems but was lower than 8-cell injection. In summary, the results suggest that 8-cell injection and PZM-3 culture medium are more beneficial to the in vitro development and chimeric efficiency of mouse-porcine chimeric embryos.

  16. Susceptibility of parent and interspecific Fl hybrid pine trees to tip moth damage in a coastal North Carolina planting

    Treesearch

    Maxine T. Highsmith; John Frampton; David 0' Malley; James Richmond; Martesa Webb

    2001-01-01

    Tip moth damage arnong families of parent pine species and their interspecific F1 hybrids was quantitatively assessed in a coastal planting in North Carolina. Three slash pine (Pinus elliotti var. elliotti Engelm.), two loblolly pine (Pinus taeda L.), and four interspecific F1 hybrid pine families were used. The...

  17. The Effect of Parasitism and Interpopulation Hybridization on Aedes albopictus (Diptera: Culicidae) Fitness.

    PubMed

    Tseng, Michelle

    2017-09-01

    Recent research in mosquito population genetics suggests that interpopulation hybridization has likely contributed to the rapid spread of the container-breeding mosquitoes. Here, I used laboratory experiments to investigate whether interpopulation Aedes (Stegomyia) albopictus (Skuse) F1 and F2 hybrids exhibit higher fitness than parental populations, and whether hybrid mosquito performance is related to infection by the coevolved protozoan parasite Ascogregarina taiwanensis (Lien and Levine). Overall, there were significant differences in development time, wing length, and survival between the two parental mosquito populations, but no difference in per capita growth rate r. Hybrid mosquitoes were generally intermediate in phenotype to the parentals, except that F2 females were significantly larger than the midparent average. In addition, As. taiwanensis parasites produced fewest oocysts when they were reared in hosts of hybrid origin. These data suggest that hybridization between previously isolated mosquito populations can result in slight increases in potential mosquito reproductive success, via increased hybrid body size, and via the temporary escape from coevolved parasites. These findings are significant because studies have shown that even slight hybrid vigor can have positive fitness consequences for population persistence. Although this was a laboratory experiment extending only to the F2 generation, many other invasive insects also carry coevolved parasites, and thus the patterns seen in this mosquito system may be broadly relevant. © 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.

  18. Proteomic analysis of muscle between hybrid abalone and parental lines Haliotis gigantea Reeve and Haliotis discus hannai Ino

    PubMed Central

    Di, G; Luo, X; You, W; Zhao, J; Kong, X; Ke, C

    2015-01-01

    To understand the potential molecular mechanism of heterosis, protein expression patterns were compared from hybrids of Haliotis gigantea (G) and Haliotis discus hannai (D) using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight analyses. Expression differences were observed in muscle samples from the four groups with 673±21.0 stained spots for H. discus hannai ♀ × H. discus hannai ♂ (DD), 692±25.6 for H. gigantea ♀ × H. gigantea ♂ (GG), 679±16.2 for H. discus hannai ♀ × H. gigantea ♂ (DG) (F1 hybrid) and 700±19 for H. gigantea ♀ × H. discus hannai ♂ (GD) (F1 hybrid). Different 2-DE image muscle protein spots had a mirrored relationship between purebreds and the F1 hybrid, suggesting that all stained spots in F1 hybrid muscle were on 2-DEs from parents. DD and DG clustered together first, and then clustered with GD, whereas the distance of DD and GG was maximal according to hierarchical cluster analysis. We identified 136 differentially expressed protein spots involved in major biological processes, including energy metabolism and stress response. Most energy metabolism proteins were additive, and stress-induced proteins displayed additivity or over-dominance. In these 136 identified protein spots, hybrid offspring with additivity or over-dominance accounted for 68.38%. Data show that a proteomic approach can provide functional prediction of abalone interspecific hybridization. PMID:25669609

  19. Influence of Taxonomic Relatedness and Chemical Mode of Action in Acute Interspecies Estimation Models for Aquatic species

    EPA Science Inventory

    Ecological risks to aquatic organisms are typically assessed using toxicity data for relatively few species and with limited understanding of relative species sensitivity. We developed a comprehensive set of interspecies correlation estimation (ICE) models for aquatic organisms a...

  20. Interspecies communication between plant and mouse gut host cells through edible plant derived exosome-like nanoparticles.

    PubMed

    Mu, Jingyao; Zhuang, Xiaoying; Wang, Qilong; Jiang, Hong; Deng, Zhong-Bin; Wang, Baomei; Zhang, Lifeng; Kakar, Sham; Jun, Yan; Miller, Donald; Zhang, Huang-Ge

    2014-07-01

    Exosomes, small vesicles participating in intercellular communication, have been extensively studied recently; however, the role of edible plant derived exosomes in interspecies communication has not been investigated. Here, we investigate the biological effects of edible plant derived exosome-like nanoparticles (EPDENs) on mammalian cells. In this study, exosome-like nanoparticles from four edible plants were isolated and characterized. We show that these EPDENs contain proteins, lipids, and microRNA. EPDENs are taken up by intestinal macrophages and stem cells. The results generated from EPDEN-transfected macrophages indicate that ginger EPDENs preferentially induce the expression of the antioxidation gene, heme oxygenase-1 and the anti-inflammatory cytokine, IL-10; whereas grapefruit, ginger, and carrot EPDENs promote activation of nuclear factor like (erythroid-derived 2). Furthermore, analysis of the intestines of canonical Wnt-reporter mice, i.e. B6.Cg-Tg(BAT-lacZ)3Picc/J mice, revealed that the numbers of β-galactosidase(+) (β-Gal) intestinal crypts are increased, suggesting that EPDEN treatment of mice leads to Wnt-mediated activation of the TCF4 transcription machinery in the crypts. The data suggest a role for EPDEN-mediated interspecies communication by inducing expression of genes for anti-inflammation cytokines, antioxidation, and activation of Wnt signaling, which are crucial for maintaining intestinal homeostasis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Activated graphene as a cathode material for Li-ion hybrid supercapacitors.

    PubMed

    Stoller, Meryl D; Murali, Shanthi; Quarles, Neil; Zhu, Yanwu; Potts, Jeffrey R; Zhu, Xianjun; Ha, Hyung-Wook; Ruoff, Rodney S

    2012-03-14

    Chemically activated graphene ('activated microwave expanded graphite oxide', a-MEGO) was used as a cathode material for Li-ion hybrid supercapacitors. The performance of a-MEGO was first verified with Li-ion electrolyte in a symmetrical supercapacitor cell. Hybrid supercapacitors were then constructed with a-MEGO as the cathode and with either graphite or Li(4)Ti(5)O(12) (LTO) for the anode materials. The results show that the activated graphene material works well in a symmetrical cell with the Li-ion electrolyte with specific capacitances as high as 182 F g(-1). In a full a-MEGO/graphite hybrid cell, specific capacitances as high as 266 F g(-1) for the active materials at operating potentials of 4 V yielded gravimetric energy densities for a packaged cell of 53.2 W h kg(-1).

  2. [Mechanisms of viral emergence and interspecies transmission: the exemple of simian foamy viruses in Central Africa].

    PubMed

    Gessain, Antoine

    2013-12-01

    A large proportion of viral pathogens that have emerged during the last decades in humans are considered to have originated from various animal species. This is well exemplified by several recent epidemics such as those of Nipah, Severe Acute Respiratory Syndrome, Avian flu, Ebola, Monkeypox, and Hantaviruses. After the initial interspecies transmission per se, the viruses can disseminate into the human population through various and distinct mechanisms. Some of them are well characterized and understood, thus allowing a certain level of risk control and prevention. Surprisingly and in contrast, the initial steps that lead to the emergence of several viruses, and of their associated diseases, remain still poorly understood. Epidemiological field studies conducted in certain specific high-risk populations are thus necessary to obtain new insights into the early events of this emergence process. Human infections by simian viruses represent increasing public health concerns. Indeed, by virtue of their genetic andphysiological similarities, non-human primates (NHPs) are considered to be likely the sources of viruses that can infect humans and thus may pose a significant threat to human population. This is well illustrated by retroviruses, which have the ability to cross species, adapt to a new host and sometimes spread within these new species. Sequence comparison and phylogenetic studies have thus clearly showed that the emergence of human immunodeficiency virus type 1 (HIV-1) and HIV-2 in humans have resulted from several independent interspecies transmissions of different SIV types from Chimpanzees and African monkeys (including sooty mangabeys), respectively, probably during the first part of the last century. The situation for Human T cell Lymphotropic virus type 1 (HTLV-1) is, for certain aspects, quite comparable. Indeed, the origin of most HTLV-1 subtypes appears to be linked to interspecies transmission between STLV-1-infected monkeys and humans, followed by

  3. Controlled fabrication of PANI/CNF hybrid films: molecular interaction induced various micromorphologies and electrochemical properties.

    PubMed

    Xu, Guiheng; Xu, Dongdong; Zhang, Jianan; Wang, Kaixi; Chen, Zhimin; Chen, Jiafu; Xu, Qun

    2013-12-01

    In this paper, a facile and efficient method is reported to prepare polyaniline/carbon nanofiber (PANI/CNF) hybrid films by in situ chemical polymerization of aniline. The various morphologies and microstructures of PANI/CNF hybrid films can be controlled by adjusting the concentration of aniline and different acids as the protonation reagent, and the formation mechanism is illustrated in this study. The surface morphologies and chemical structure of the PANI/CNF hybrid films are characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), water contact angle (CA), FT-IR, Raman, and UV-vis spectrophotometers. The different morphology of uniformly coated, twist-tangled, and needle-like PANI built on CNF films are obtained by using HCl, H2SO4, and HClO4 as protonation reagent and the obtained hybrid films are labeled as PANI/CNF-f1, PANI/CNF-f2, and PANI/CNF-f3, respectively. We demonstrated that the different protonation reagent has the determined effect on the surface properties of the obtained hybrid films that can transfer from hydrophilic to hydrophobic. Besides, the various morphologies of PANI play an important role in their electrochemical properties. PANI/CNF-f3 exhibits higher specific capacitance and better stability than that of the PANI/CNF-f1 and PANI/CNF-f2. Considering its unique needle-like structure, this work is a proof of concept that micro-structure and morphology can determine the macro-properties. And this study supplies a facile method to fabricate PANI/CNF hybrid films that can be used as electrode materials in supercapacitors. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Rare Earth 4f Hybridization with the GaN Valence Band

    DTIC Science & Technology

    2012-01-01

    DOS of Ga17GdN18. and Auger-like electrons emitted in a super Coster– Kronig process [52] 4d104fN + hν → [4d94fN+1]∗ → 4d104fN−1 + e−, (2) where...similar, albeit not identical, response for GaN:Er compared to GaN:Gd at the photon energy characteristic for the Er 4d → 4f super Coster– Kronig resonance

  5. Flow Sorting and Sequencing Meadow Fescue Chromosome 4F1[C][W

    PubMed Central

    Kopecký, David; Martis, Mihaela; Číhalíková, Jarmila; Hřibová, Eva; Vrána, Jan; Bartoš, Jan; Kopecká, Jitka; Cattonaro, Federica; Stočes, Štěpán; Novák, Petr; Neumann, Pavel; Macas, Jiří; Šimková, Hana; Studer, Bruno; Asp, Torben; Baird, James H.; Navrátil, Petr; Karafiátová, Miroslava; Kubaláková, Marie; Šafář, Jan; Mayer, Klaus; Doležel, Jaroslav

    2013-01-01

    The analysis of large genomes is hampered by a high proportion of repetitive DNA, which makes the assembly of short sequence reads difficult. This is also the case in meadow fescue (Festuca pratensis), which is known for good abiotic stress resistance and has been used in intergeneric hybridization with ryegrasses (Lolium spp.) to produce Festulolium cultivars. In this work, we describe a new approach to analyze the large genome of meadow fescue, which involves the reduction of sample complexity without compromising information content. This is achieved by dissecting the genome to smaller parts: individual chromosomes and groups of chromosomes. As the first step, we flow sorted chromosome 4F and sequenced it by Illumina with approximately 50× coverage. This provided, to our knowledge, the first insight into the composition of the fescue genome, enabled the construction of the virtual gene order of the chromosome, and facilitated detailed comparative analysis with the sequenced genomes of rice (Oryza sativa), Brachypodium distachyon, sorghum (Sorghum bicolor), and barley (Hordeum vulgare). Using GenomeZipper, we were able to confirm the collinearity of chromosome 4F with barley chromosome 4H and the long arm of chromosome 5H. Several new tandem repeats were identified and physically mapped using fluorescence in situ hybridization. They were found as robust cytogenetic markers for karyotyping of meadow fescue and ryegrass species and their hybrids. The ability to purify chromosome 4F opens the way for more efficient analysis of genomic loci on this chromosome underlying important traits, including freezing tolerance. Our results confirm that next-generation sequencing of flow-sorted chromosomes enables an overview of chromosome structure and evolution at a resolution never achieved before. PMID:24096412

  6. Development of algal interspecies correlation estimation models for chemical hazard assessment.

    PubMed

    Brill, Jessica L; Belanger, Scott E; Chaney, Joel G; Dyer, Scott D; Raimondo, Sandy; Barron, Mace G; Pittinger, Charles A

    2016-09-01

    Web-based Interspecies Correlation Estimation (ICE) is an application developed to predict the acute toxicity of a chemical from 1 species to another taxon. Web-ICE models use the acute toxicity value for a surrogate species to predict effect values for other species, thus potentially filling in data gaps for a variety of environmental assessment purposes. Web-ICE has historically been dominated by aquatic and terrestrial animal prediction models. Web-ICE models for algal species were essentially absent and are addressed in the present study. A compilation of public and private sector-held algal toxicity data were compiled and reviewed for quality based on relevant aspects of individual studies. Interspecies correlations were constructed from the most commonly tested algal genera for a broad spectrum of chemicals. The ICE regressions were developed based on acute 72-h and 96-h endpoint values involving 1647 unique studies on 476 unique chemicals encompassing 40 genera and 70 species of green, blue-green, and diatom algae. Acceptance criteria for algal ICE models were established prior to evaluation of individual models and included a minimum sample size of 3, a statistically significant regression slope, and a slope estimation parameter ≥0.65. A total of 186 ICE models were possible at the genus level, with 21 meeting quality criteria; and 264 ICE models were developed at the species level, with 32 meeting quality criteria. Algal ICE models will have broad utility in screening environmental hazard assessments, data gap filling in certain regulatory scenarios, and as supplemental information to derive species sensitivity distributions. Environ Toxicol Chem 2016;35:2368-2378. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public

  7. Fibonacci-Pell Hybridities

    ERIC Educational Resources Information Center

    Koshy, Thomas; Gao, Zhenguang

    2012-01-01

    We develop a recurrence satisfied by the Fibonacci and Pell families. We then use it to find explicit formulae and generating functions for the hybrids "F[subscript n]P[subscript n]", "L[subscript n]P[subscript n]", "F[subscript n]Q[subscript n]" and "L[subscript n]Q[subscript n]", where "F[subscript n]", "L[subscript n]", "P[subscript n]" and…

  8. Engineering three-dimensional hybrid supercapacitors and microsupercapacitors for high-performance integrated energy storage

    PubMed Central

    El-Kady, Maher F.; Ihns, Melanie; Li, Mengping; Hwang, Jee Youn; Mousavi, Mir F.; Chaney, Lindsay; Lech, Andrew T.; Kaner, Richard B.

    2015-01-01

    Supercapacitors now play an important role in the progress of hybrid and electric vehicles, consumer electronics, and military and space applications. There is a growing demand in developing hybrid supercapacitor systems to overcome the energy density limitations of the current generation of carbon-based supercapacitors. Here, we demonstrate 3D high-performance hybrid supercapacitors and microsupercapacitors based on graphene and MnO2 by rationally designing the electrode microstructure and combining active materials with electrolytes that operate at high voltages. This results in hybrid electrodes with ultrahigh volumetric capacitance of over 1,100 F/cm3. This corresponds to a specific capacitance of the constituent MnO2 of 1,145 F/g, which is close to the theoretical value of 1,380 F/g. The energy density of the full device varies between 22 and 42 Wh/l depending on the device configuration, which is superior to those of commercially available double-layer supercapacitors, pseudocapacitors, lithium-ion capacitors, and hybrid supercapacitors tested under the same conditions and is comparable to that of lead acid batteries. These hybrid supercapacitors use aqueous electrolytes and are assembled in air without the need for expensive “dry rooms” required for building today’s supercapacitors. Furthermore, we demonstrate a simple technique for the fabrication of supercapacitor arrays for high-voltage applications. These arrays can be integrated with solar cells for efficient energy harvesting and storage systems. PMID:25831542

  9. Safety of oxytetracycline (Terramycin TM-100F) administered in feed to hybrid striped bass, walleyes, and yellow perch

    USGS Publications Warehouse

    Gaikowski, M.P.; Wolf, J.C.; Schleis, S.M.; Gingerich, W.H.

    2003-01-01

    Oxytetracycline (Terramycin TM-100F, a medicated premix containing oxytetracycline at 220 g/kg) is approved in the United States to control certain systemic bacterial diseases of salmon and catfish when fed at a rate of 55-82.5 mg per kilogram of bodyweight per day for 10 d. Although oxytetracycline may also control certain systemic bacterial infections in coolwater or scaled warmwater fish, no safety data for such species are available. Our objective was to determine the safety of oxytetracycline administered in feed at nominal doses of 0, 82.5, 248, or 413 mg??kg-1??d-1 to yellow perch Perca flavescens and hybrid striped bass (striped bass Morone saxatilis x white bass M. chrysops) for 10 d and to walleye Sander vitreus (formerly Stizostedion vitreum) for 20 d. Yellow perch and hybrid striped bass consumed 50% to 100% of the diet, whereas walleye feed consumption was occasionally less than 50% of the diet. Feed or fecal material was present in the gastrointestinal tract of all necropsied walleyes except for one control fish. The single growth effect was that hybrid striped bass offered a nominal dose of 413 mg??kg-1??d-1 were significantly smaller than untreated controls. Oxytetracycline-related histopathological findings were limited to walleyes and were of low severity. The histopathological findings included decreased hematopoietic-lymphopoietic (H&L) tissue in the anterior kidneys, diffuse hyperplasia of the gill filament epithelium, and a decreased prevalence of fish with eosinophilic droplets in their renal tubular epithelial cells. Although the incidence of decreased H&L tissue tended to increase in proportion to oxytetracycline dose, this finding was statistically significant only for fish that received a nominal dose of 413 mg??kg-1??d-1. Given the pathogenicity of the types of bacteria that are controlled by oxytetracycline treatment and the long history of its use in major aquaculture species, the relative risk of the minor oxytetracycline

  10. Probing the 5 f electrons in Am-I by hybrid density functional theory

    NASA Astrophysics Data System (ADS)

    Atta-Fynn, Raymond; Ray, Asok K.

    2009-11-01

    The ground states of the actinides and their compounds continue to be matters of considerable controversies. Experimentally, Americium-I (Am-I) is a non-magnetic dhcp metal whereas theoretically an anti-ferromagnetic ground state is predicted. We show that hybrid density functional theory, which admixes a fraction, λ, of exact Hartree-Fock (HF) exchange with approximate DFT exchange, can correctly reproduce the ground state properties of Am. In particular, for λ=0.40, we obtain a non-magnetic ground state with equilibrium atomic volume, bulk modulus, 5 f electron population, and the density of electronic states all in good agreement with experimental data. We argue that the exact HF exchange corrects the overestimation of the approximate DFT exchange interaction.

  11. A Hybrid of Deep Network and Hidden Markov Model for MCI Identification with Resting-State fMRI.

    PubMed

    Suk, Heung-Il; Lee, Seong-Whan; Shen, Dinggang

    2015-10-01

    In this paper, we propose a novel method for modelling functional dynamics in resting-state fMRI (rs-fMRI) for Mild Cognitive Impairment (MCI) identification. Specifically, we devise a hybrid architecture by combining Deep Auto-Encoder (DAE) and Hidden Markov Model (HMM). The roles of DAE and HMM are, respectively, to discover hierarchical non-linear relations among features, by which we transform the original features into a lower dimension space, and to model dynamic characteristics inherent in rs-fMRI, i.e. , internal state changes. By building a generative model with HMMs for each class individually, we estimate the data likelihood of a test subject as MCI or normal healthy control, based on which we identify the clinical label. In our experiments, we achieved the maximal accuracy of 81.08% with the proposed method, outperforming state-of-the-art methods in the literature.

  12. A Hybrid of Deep Network and Hidden Markov Model for MCI Identification with Resting-State fMRI

    PubMed Central

    Suk, Heung-Il; Lee, Seong-Whan; Shen, Dinggang

    2015-01-01

    In this paper, we propose a novel method for modelling functional dynamics in resting-state fMRI (rs-fMRI) for Mild Cognitive Impairment (MCI) identification. Specifically, we devise a hybrid architecture by combining Deep Auto-Encoder (DAE) and Hidden Markov Model (HMM). The roles of DAE and HMM are, respectively, to discover hierarchical non-linear relations among features, by which we transform the original features into a lower dimension space, and to model dynamic characteristics inherent in rs-fMRI, i.e., internal state changes. By building a generative model with HMMs for each class individually, we estimate the data likelihood of a test subject as MCI or normal healthy control, based on which we identify the clinical label. In our experiments, we achieved the maximal accuracy of 81.08% with the proposed method, outperforming state-of-the-art methods in the literature. PMID:27054199

  13. Dynamic nucleolar activity in wheat × Aegilops hybrids: evidence of C-genome dominance.

    PubMed

    Mirzaghaderi, Ghader; Abdolmalaki, Zinat; Zohouri, Mohsen; Moradi, Zeinab; Mason, Annaliese S

    2017-08-01

    NOR loci of C-subgenome are dominant in wheat × Aegilops interspecific hybrids, which may have evolutionary implications for wheat group genome dynamics and evolution. After interspecific hybridisation, some genes are often expressed from only one of the progenitor species, shaping subsequent allopolyploid genome evolution processes. A well-known example is nucleolar dominance, i.e. the formation of cell nucleoli from chromosomes of only one parental species. We studied nucleolar organizing regions (NORs) in diploid Aegilops markgrafii (syn: Ae. caudata; CC), Ae. umbellulata (UU), allotetraploids Aegilops cylindrica (C c C c D c D c ) and Ae. triuncialis (C t C t U t U t ), synthetic interspecific F 1 hybrids between these two allotetraploids and bread wheat (Triticum aestivum, AABBDD) and in F 3 generation hybrids with genome composition AABBDDC t C t U t U t using silver staining and fluorescence in situ hybridization (FISH). In Ae. markgrafii (CC), NORs of both 1C and 5C or only 5C chromosome pairs were active in different individual cells, while only NORs on 1U chromosomes were active in Ae. umbellulata (UU). Although all 35S rDNA loci of the C t subgenome (located on 1C t and 5C t ) were active in Ae. triuncialis, only one pair (occupying either 1C c or 5C c ) was active in Ae. cylindrica, depending on the genotype studied. These C-genome expression patterns were transmitted to the F 1 and F 3 generations. Wheat chromosome NOR activity was variable in Ae. triuncialis × T. aestivum F 1 seeds, but silenced by the F 3 generation. No effect of maternal or paternal cross direction was observed. These results indicate that C-subgenome NOR loci are dominant in wheat × Aegilops interspecific hybrids, which may have evolutionary implications for wheat group genome dynamics and allopolyploid evolution.

  14. Artificial plasma cusp generated by upper hybrid instabilities in HF heating experiments at HAARP

    NASA Astrophysics Data System (ADS)

    Kuo, Spencer; Snyder, Arnold

    2013-05-01

    High Frequency Active Auroral Research Program digisonde was operated in a fast mode to record ionospheric modifications by the HF heating wave. With the O mode heater of 3.2 MHz turned on for 2 min, significant virtual height spread was observed in the heater off ionograms, acquired beginning the moment the heater turned off. Moreover, there is a noticeable bump in the virtual height spread of the ionogram trace that appears next to the plasma frequency (~ 2.88 MHz) of the upper hybrid resonance layer of the HF heating wave. The enhanced spread and the bump disappear in the subsequent heater off ionograms recorded 1 min later. The height distribution of the ionosphere in the spread situation indicates that both electron density and temperature increases exceed 10% over a large altitude region (> 30 km) from below to above the upper hybrid resonance layer. This "mini cusp" (bump) is similar to the cusp occurring in daytime ionograms at the F1-F2 layer transition, indicating that there is a small ledge in the density profile reminiscent of F1-F2 layer transitions. Two parametric processes exciting upper hybrid waves as the sidebands by the HF heating waves are studied. Field-aligned purely growing mode and lower hybrid wave are the respective decay modes. The excited upper hybrid and lower hybrid waves introduce the anomalous electron heating which results in the ionization enhancement and localized density ledge. The large-scale density irregularities formed in the heat flow, together with the density irregularities formed through the parametric instability, give rise to the enhanced virtual height spread. The results of upper hybrid instability analysis are also applied to explain the descending feature in the development of the artificial ionization layers observed in electron cyclotron harmonic resonance heating experiments.

  15. Constitutive heterochromatin in chromosomes of duck hybrids and goose hybrids.

    PubMed

    Wójcik, E; Smalec, E

    2017-01-01

    Constitutive heterochromatin is a highly condensed fraction of chromatin in chromosomes. It is characterized by a high degree of polymorphism. Heterochromatin is located in the centromeric, telomeric, and interstitial parts of chromosomes. We used the CBG ( C: banding using B: arium hydroxide by G: iemsa) staining technique to identify heterochromatin in chromosomes. Analysis of karyotypes of F1 hybrids resulting from intergeneric hybridization of ducks (A. platyrhynchos × C. moschata) and interspecific crosses of geese (A. anser × A. cygnoides) were used to compare the karyotypes of 2 species of duck and 2 species of geese, as well as to compare the hybrids with the parent species. The localization of C-bands and their size were determined. In the duck hybrid, greater amounts of heterochromatin were noted in the homologous chromosomes from the duck A. platyrhynchos than in the chromosomes from the duck C. moschata. In the goose hybrid more heterochromatin was observed in the homologous chromosomes from the goose A. cygnoides than in the chromosomes from the goose A. anser. Comparison of chromosomes from the duck hybrid with chromosomes of the ducks A. platyrhynchos and C. moschata revealed nearly twice as much constitutive heterochromatin in the chromosomes of the hybrid. When chromosomes from the goose hybrid were compared with those of the geese A. anser and A. cygnoides, differences in the average content of heterochromatin were observed on only a few chromosomes. © 2016 Poultry Science Association Inc.

  16. Parameters to Maximize 2f2-f1 Distortion Product Otoacoustic Emission Levels

    ERIC Educational Resources Information Center

    Horn, Jennifer H.; Pratt, Shiela R.; Durrant, John D.

    2008-01-01

    Purpose: Past research has established parameters for the 2f1-f2 distortion product otoacoustic emissions (DPOAEs) that enhance response levels (e.g., L1 - L2 = 10 dB; f2/f1 = 1.22; L1, L2 = 65, 55 dB SPL). These same parameters do not optimize 2f2-f1 DPOAEs. Therefore, this study was conducted to evaluate more completely those parameters that…

  17. Genetic investigation of natural hybridization between rainbow and coastal cutthroat trout in the copper River Delta, Alaska

    USGS Publications Warehouse

    Williams, I.; Reeves, G.H.; Graziano, S.L.; Nielsen, J.L.

    2007-01-01

    Molecular genetic methods were used to quantify natural hybridization between rainbow trout Oncorhynchus mykiss or steelhead (anadromous rainbow trout) and coastal cutthroat trout O. clarkii clarkii collected in the Copper River delta, Southeast Alaska. Eleven locations were sampled to determine the extent of hybridization and the distribution of hybrids. Four diagnostic nuclear microsatellite loci and four species-specific simple sequence repeat markers were used in combination with restriction fragment length polymorphism analyses of NADH dehydrogenase 5/6 (ND5/6) mitochondrial DNA (mtDNA) to investigate the genetic structure of trout from both species and identify putative interspecific hybrids. Hybrids were found in 7 of the 11 streams sampled in the Copper River delta, the extent of hybridization across all streams varying from 0% to 58%. Hybrid trout distribution appeared to be nonrandom, most individuals of mixed taxonomic ancestry being detected in streams containing rainbow trout rather than in streams containing coastal cutthroat trout. Genotypic disequilibrium was observed among microsatellite loci in populations with high levels of hybridization. We found no significant correlation between unique stream channel process groups and the number of hybrid fish sampled. Eighty-eight percent of fish identified as first-generation hybrids (F1) in two populations contained coastal cutthroat trout mtDNA, suggesting directionality in hybridization. However, dominance of coastal cutthroat trout mtDNA was not observed at a third location containing F1 hybrids, indicating that interspecific mating behavior varied among locations. Backcrossed individuals were found in drainages lacking F1 hybrids and in populations previously thought to contain a single species. The extent and distribution of backcrossed individuals suggested that at least some hybrids are reproductively viable and backcrossed hybrid offspring move throughout the system.

  18. INTERSPECIES CORRELATION ESTIMATION (ICE) FOR ACUTE TOXICITY TO AQUATIC ORGANISMS AND WILDLIFE. II. USER MANUAL AND SOFTWARE

    EPA Science Inventory

    Asfaw, Amha, Mark R. Ellersieck and Foster L. Mayer. 2003. Interspecies Correlation Estimations (ICE) for Acute Toxicity to Aquatic Organisms and Wildlife. II. User Manual and Software. EPA/600/R-03/106. U.S. Environmental Protection Agency, National Health and Environmental Effe...

  19. M2-F1 cockpit

    NASA Technical Reports Server (NTRS)

    1963-01-01

    This photo shows the cockpit configuration of the M2-F1 wingless lifting body. With a top speed of about 120 knots, the M2-F1 had a simple instrument panel. Besides the panel itself, the ribs of the wooden shell (left) and the control stick (center) are also visible. The wingless, lifting body aircraft design was initially conceived as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne to prove it could fly safely and to train pilots before they were towed behind a C-47

  20. Comparison of Species Sensitivity Distributions Derived from Interspecies Correlation Models to Distributions used to Derive Water Quality Criteria

    EPA Science Inventory

    Species sensitivity distributions (SSD) require a large number of measured toxicity values to define a chemical’s toxicity to multiple species. This investigation comprehensively evaluated the accuracy of SSDs generated from toxicity values predicted from interspecies correlation...

  1. Preparation of layered graphene and tungsten oxide hybrids for enhanced performance supercapacitors.

    PubMed

    Xing, Ling-Li; Huang, Ke-Jing; Fang, Lin-Xia

    2016-11-01

    Tungsten oxide (WO 3 ), which was originally poor in capacitive performance, is made into an excellent electrode material for supercapacitors by dispersing it on graphene (Gr). The obtained Gr-WO 3 hybrids are characterized by X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy and scanning electron microscopy techniques, and evaluated as electrode materials for high-performance supercapacitors by cyclic voltammetry, galvanostatic charge-discharge curves and electrochemical impedance spectroscopy. A great improvement in specific capacitance is achieved with the present hybrids, from 255 F g -1 for WO 3 nanoparticles to 580 F g -1 for Gr-WO 3 hybrids (scanned at 1 A g -1 in 2 M KOH over a potential window of 0 to 0.45 V). The Gr-WO 3 hybrid exhibits an excellent high rate capability and good cycling stability with more than 92% capacitance retention over 1000 cycles at a current density of 5 A g -1 . The enhancement in supercapacitor performance of Gr-WO 3 is not only attributed to its unique nanostructure with large specific surface area, but also its excellent electro-conductivity, which facilitates efficient charge transport and promotes electrolyte diffusion. As a whole, this work indicates that Gr-WO 3 hybrids are a promising electrode material for high-performance supercapacitors.

  2. Potential for direct interspecies electron transfer in methanogenic wastewater digester aggregates.

    PubMed

    Morita, Masahiko; Malvankar, Nikhil S; Franks, Ashley E; Summers, Zarath M; Giloteaux, Ludovic; Rotaru, Amelia E; Rotaru, Camelia; Lovley, Derek R

    2011-01-01

    Mechanisms for electron transfer within microbial aggregates derived from an upflow anaerobic sludge blanket reactor converting brewery waste to methane were investigated in order to better understand the function of methanogenic consortia. The aggregates were electrically conductive, with conductivities 3-fold higher than the conductivities previously reported for dual-species aggregates of Geobacter species in which the two species appeared to exchange electrons via interspecies electron transfer. The temperature dependence response of the aggregate conductance was characteristic of the organic metallic-like conductance previously described for the conductive pili of Geobacter sulfurreducens and was inconsistent with electron conduction through minerals. Studies in which aggregates were incubated with high concentrations of potential electron donors demonstrated that the aggregates had no significant capacity for conversion of hydrogen to methane. The aggregates converted formate to methane but at rates too low to account for the rates at which that the aggregates syntrophically metabolized ethanol, an important component of the reactor influent. Geobacter species comprised 25% of 16S rRNA gene sequences recovered from the aggregates, suggesting that Geobacter species may have contributed to some but probably not all of the aggregate conductivity. Microorganisms most closely related to the acetate-utilizing Methanosaeta concilii accounted for more than 90% of the sequences that could be assigned to methane producers, consistent with the poor capacity for hydrogen and formate utilization. These results demonstrate for the first time that methanogenic wastewater aggregates can be electrically conductive and suggest that direct interspecies electron transfer could be an important mechanism for electron exchange in some methanogenic systems.

  3. [Features of interaction bacterial strains Micrococcus luteus LBK1 from plants varieties/hybrids cucumber and sweet pepper and with fungus Fusarium oxysporum Scelecht].

    PubMed

    Parfeniuk, A; Sterlikova, O; Beznosko, I; Krut', V

    2014-01-01

    The article presents the results of studying the impact of bacterial strain M. luteus LBK1, stimulating the growth and development of plant varieties/hybrids of cucumber and sweet pepper on the intensity of sporulation of the fungus F. oxysporum Scelecht--fusariose rot pathogen.

  4. Inheritance and variability of tolerance to Verticillium dahliae Kleb amoung geographically remote F1-F2 hybrids of Gossypium hirsutum L.

    USDA-ARS?s Scientific Manuscript database

    One of the most important problems for cotton breeding in Uzbekistan is development of Verticillium dahliae tolerant varieties. One approach is to utilize ecologically remote intraspecific and interspecific hybridization with local commercial cultivars. To this end, we have conducted genetically b...

  5. The Contribution of the Y Chromosome to Hybrid Male Sterility in House Mice

    PubMed Central

    Campbell, Polly; Good, Jeffrey M.; Dean, Matthew D.; Tucker, Priscilla K.; Nachman, Michael W.

    2012-01-01

    Hybrid sterility in the heterogametic sex is a common feature of speciation in animals. In house mice, the contribution of the Mus musculus musculus X chromosome to hybrid male sterility is large. It is not known, however, whether F1 male sterility is caused by X–Y or X-autosome incompatibilities or a combination of both. We investigated the contribution of the M. musculus domesticus Y chromosome to hybrid male sterility in a cross between wild-derived strains in which males with a M. m. musculus X chromosome and M. m. domesticus Y chromosome are partially sterile, while males from the reciprocal cross are reproductively normal. We used eight X introgression lines to combine different X chromosome genotypes with different Y chromosomes on an F1 autosomal background, and we measured a suite of male reproductive traits. Reproductive deficits were observed in most F1 males, regardless of Y chromosome genotype. Nonetheless, we found evidence for a negative interaction between the M. m. domesticus Y and an interval on the M. m. musculus X that resulted in abnormal sperm morphology. Therefore, although F1 male sterility appears to be caused mainly by X-autosome incompatibilities, X–Y incompatibilities contribute to some aspects of sterility. PMID:22595240

  6. The contribution of the Y chromosome to hybrid male sterility in house mice.

    PubMed

    Campbell, Polly; Good, Jeffrey M; Dean, Matthew D; Tucker, Priscilla K; Nachman, Michael W

    2012-08-01

    Hybrid sterility in the heterogametic sex is a common feature of speciation in animals. In house mice, the contribution of the Mus musculus musculus X chromosome to hybrid male sterility is large. It is not known, however, whether F1 male sterility is caused by X-Y or X-autosome incompatibilities or a combination of both. We investigated the contribution of the M. musculus domesticus Y chromosome to hybrid male sterility in a cross between wild-derived strains in which males with a M. m. musculus X chromosome and M. m. domesticus Y chromosome are partially sterile, while males from the reciprocal cross are reproductively normal. We used eight X introgression lines to combine different X chromosome genotypes with different Y chromosomes on an F1 autosomal background, and we measured a suite of male reproductive traits. Reproductive deficits were observed in most F1 males, regardless of Y chromosome genotype. Nonetheless, we found evidence for a negative interaction between the M. m. domesticus Y and an interval on the M. m. musculus X that resulted in abnormal sperm morphology. Therefore, although F1 male sterility appears to be caused mainly by X-autosome incompatibilities, X-Y incompatibilities contribute to some aspects of sterility.

  7. Hybridization between Yellowstone cutthroat trout and rainbow trout alters the expression of muscle growth-related genes and their relationships with growth patterns

    USGS Publications Warehouse

    Ostberg, Carl O.; Chase, Dorothy M.; Hauser, Lorenz

    2015-01-01

    Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss) and cutthroat trout (O. clarkii) produce viable hybrids in the wild, and introgressive hybridization with introduced rainbow trout is a major conservation concern for native cutthroat trout. The two species differ in body shape, which is likely an evolutionary adaptation to their native environments, and their hybrids tend to show intermediate morphology. The characterization of gene expression patterns may provide insights on the genetic basis of hybrid and parental morphologies, as well as on the ecological performance of hybrids in the wild. Here, we evaluated the expression of eight growth-related genes (MSTN-1a, MSTN-1b, MyoD1a, MyoD1b, MRF-4, IGF-1, IGF-2, and CAST-L) and the relationship of these genes with growth traits (length, weight, and condition factor) in six line crosses: both parental species, both reciprocal F1 hybrids, and both first-generation backcrosses (F1 x rainbow trout and F1 x cutthroat trout). Four of these genes were differentially expressed among rainbow, cutthroat, and their hybrids. Transcript abundance was significantly correlated with growth traits across the parent species, but not across hybrids. Our findings suggest that rainbow and cutthroat trout exhibit differences in muscle growth regulation, that transcriptional networks may be modified by hybridization, and that hybridization disrupts intrinsic relationships between gene expression and growth patterns that may be functionally important for phenotypic adaptations.

  8. Bulk plasma fragmentation in a C4F8 inductively coupled plasma: A hybrid modeling study

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Xia; Zhang, Yu-Ru; Gao, Fei; Wang, You-Nian; Bogaerts, Annemie

    2015-06-01

    A hybrid model is used to investigate the fragmentation of C4F8 inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. CxFy (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C4F8 inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C4F8 reaction set used in the model. The C4F8 plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.

  9. Two non-allelic nuclear genes restore fertility in a gametophytic pattern and enhance abiotic stress tolerance in the hybrid rice plant.

    PubMed

    Huang, Wenchao; Hu, Jun; Yu, Changchun; Huang, Qi; Wan, Lei; Wang, Lili; Qin, Xiaojian; Ji, Yanxiao; Zhu, Renshan; Li, Shaoqing; Zhu, Yingguo

    2012-03-01

    In indica rice, the HongLian (HL)-type combination of cytoplasmic male sterility (CMS) and fertility restoration (Rf) is widely used for the production of commercial hybrid seeds in China, Laos, Vietnam and other Southeast Asian countries. Generally, any member of the gametophytic fertility restoration system, 50% of the pollen in hybrid F(1) plants displays recovered sterility. In this study, however, a HL-type hybrid variety named HongLian You6 had approximately 75% normal (viable) pollen rather than the expected 50%. To resolve this discrepancy, several fertility segregation populations, including F(2) and BC(1)F(1) derived from the HL-CMS line Yuetai A crossed with the restorer line 9311, were constructed and subjected to genetic analysis. A gametophytic restoration model was discovered to involve two non-allelic nuclear restorer genes, Rf5 and Rf6. The Rf5 had been previously identified using a positional clone strategy. The Rf6 gene represents a new restorer gene locus, which was mapped to the short arm of chromosome 8. The hybrid F(1) plants containing one restorer gene, either Rf5 or Rf6, displayed 50% normal pollen grains with I(2)-KI solution; however, those with both Rf5 and Rf6 displayed 75% normal pollens. We also established that the hybrid F(1) plants including both non-allelic restorer genes exhibited an increased stable seed setting when subjected to stress versus the F(1) plants with only one restorer gene. Finally, we discuss the breeding scheme for the plant gametophytic CMS/Rf system.

  10. The Aryl Hydrocarbon Receptor Binds to E2F1 and Inhibits E2F1-induced Apoptosis

    PubMed Central

    Marlowe, Jennifer L.; Fan, Yunxia; Chang, Xiaoqing; Peng, Li; Knudsen, Erik S.; Xia, Ying

    2008-01-01

    Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr−/− fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, γH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of E2F1 expression. In contrast, ligand-dependent AHR activation protects these cells from etoposide-induced cell death. In cells expressing both proteins, AHR and E2F1 interact independently of the retinoblastoma protein (RB), because AHR and E2F1 coimmunoprecipitate from extracts of RB-negative cells. Additionally, chromatin immunoprecipitation assays indicate that AHR and E2F1 bind to the Apaf1 promoter at a region containing a consensus E2F1 binding site but no AHR binding sites. AHR activation represses Apaf1 and TAp73 mRNA induction by a constitutively active CHK2 expression vector. Furthermore, AHR overexpression blocks the transcriptional induction of Apaf1 and p73 and the accumulation of sub-G0/G1 cells resulting from ectopic overexpression of E2F1. These results point to a proproliferative, antiapoptotic function of the Ah receptor that likely plays a role in tumor progression. PMID:18524851

  11. Canine distemper outbreak in raccoons suggests pathogen interspecies transmission amongst alien and native carnivores in urban areas from Germany.

    PubMed

    Rentería-Solís, Zaida; Förster, Christine; Aue, Angelika; Wittstatt, Ulrich; Wibbelt, Gudrun; König, Matthias

    2014-11-07

    From December 2012 to May 2013, an outbreak occurred among urban wild carnivores from Berlin. We collected 97 free-ranging raccoons from the city area. PCR assays, histopathology and immunohistochemistry confirmed canine distemper virus (CDV) infection in 74 raccoons. Phylogenetic analysis of haemagglutinin gene fragments (1767 nucleotides) of CDV isolated from four raccoons showed close relation to CDV isolates from foxes from Germany and a domestic dog from Hungary; all belonging to the "Europe" lineage of CDV. These study results suggest an inter-species transmission of CDV as the origin for the outbreak among the raccoon population. Implications for domestic pets and suggested interspecies transmission between urban wildlife and raccoons are discussed. This is the first major outbreak of CDV amongst free-ranging raccoons in Europe. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Multiple cis-regulatory elements are involved in the complex regulation of the sieve element-specific MtSEO-F1 promoter from Medicago truncatula.

    PubMed

    Bucsenez, M; Rüping, B; Behrens, S; Twyman, R M; Noll, G A; Prüfer, D

    2012-09-01

    The sieve element occlusion (SEO) gene family includes several members that are expressed specifically in immature sieve elements (SEs) in the developing phloem of dicotyledonous plants. To determine how this restricted expression profile is achieved, we analysed the SE-specific Medicago truncatula SEO-F1 promoter (PMtSEO-F1) by constructing deletion, substitution and hybrid constructs and testing them in transgenic tobacco plants using green fluorescent protein as a reporter. This revealed four promoter regions, each containing cis-regulatory elements that activate transcription in SEs. One of these segments also contained sufficient information to suppress PMtSEO-F1 transcription in the phloem companion cells (CCs). Subsequent in silico analysis revealed several candidate cis-regulatory elements that PMtSEO-F1 shares with other SEO promoters. These putative sieve element boxes (PSE boxes) are promising candidates for cis-regulatory elements controlling the SE-specific expression of PMtSEO-F1. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Cytogenetic and morphologic approaches of hybrids from experimental crosses between Triatoma lenti Sherlock & Serafim, 1967 and T. sherlocki Papa et al., 2002 (Hemiptera: Reduviidae).

    PubMed

    Mendonça, Vagner José; Alevi, Kaio Cesar Chaboli; Medeiros, Lívia Maria de Oliveira; Nascimento, Juliana Damieli; de Azeredo-Oliveira, Maria Tercília Vilela; da Rosa, João Aristeu

    2014-08-01

    The reproductive capacity between Triatoma lenti and Triatoma sherlocki was observed in order to verify the fertility and viability of the offspring. Cytogenetic, morphological and morphometric approaches were used to analyze the differences that were inherited. Experimental crosses were performed in both directions. The fertility rate of the eggs in crosses involving T. sherlocki females was 65% and 90% in F1 and F2 offspring, respectively. In reciprocal crosses, it was 7% and 25% in F1 and F2 offspring, respectively. The cytogenetic analyses of the male meiotic process of the hybrids were performed using lacto-acetic orcein, C-banding and Feulgen techniques. The male F1 offspring presented normal chromosome behavior, a finding that was similar to those reported in parental species. However, cytogenetic analysis of F2 offspring showed errors in chromosome pairing. This post-zygotic isolation, which prevents hybrids in nature, may represent the collapse of the hybrid. This phenomenon is due to a genetic dysregulation that occurs in the chromosomes of F1. The results were similar in the hybrids from both crosses. Morphological features, such as color and size of connexive and the presence of red-orange rings on the femora, were similar to T. sherlocki, while wins size was similar to T. lenti in F1 offspring. The eggshells showed characteristics that were similar to species of origin, whereas the median process of the pygophore resulted in intermediate characteristics in the F1 and a segregating pattern in F2 offspring. Geometric morphometric techniques used on the wings showed that both F1 and F2 offspring were similar to T. lenti. These studies on the reproductive capacity between T. lenti and T. sherlocki confirm that both species are evolutionarily closed; hence, they are included in the brasiliensis subcomplex. The extremely reduced fertility observed in the F2 hybrids confirmed the specific status of the species that were analyzed. Copyright © 2014 The Authors

  14. CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity.

    PubMed

    Huang, Fei; Li, Zhen; Yan, Aihua; Zhao, Hui; Liang, Huagen; Gao, Qingyu; Qiang, Yinghuai

    2017-01-06

    Novel semiconductor photocatalysts have been the research focus and received much attention in recent years. The key issues for novel semiconductor photocatalysts are to effectively harvest solar energy and enhance the separation efficiency of the electron-hole pairs. In this work, novel Nb 3 O 7 F/CNTs hybrid nanocomposites with enhanced photocatalytic activity have been successfully synthesized by a facile hydrothermal plus etching technique. The important finding is that appropriate pH values lead to the formation of Nb 3 O 7 F nanocrystal directly. A general strategy to introdue interaction between Nb 3 O 7 F and CNTs markedly enhances the photocatalytic activity of Nb 3 O 7 F. Comparatively, Nb 3 O 7 F/CNTs nanocomposites exhibit higher photodegradation efficiency and faster photodegradation rate in the solution of methylene blue (MB) under visible-light irradiation. The higher photocatalytic activity may be attributed to more exposed active sites, higher carrier migration and narrower bandgap because of good synergistic effect. The results here may inspire more engineering, new design and facile fabrication of novel photocatalysts with highly photocatalytic activity.

  15. CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

    PubMed Central

    Huang, Fei; Li, Zhen; Yan, Aihua; Zhao, Hui; Liang, Huagen; Gao, Qingyu; Qiang, Yinghuai

    2017-01-01

    Novel semiconductor photocatalysts have been the research focus and received much attention in recent years. The key issues for novel semiconductor photocatalysts are to effectively harvest solar energy and enhance the separation efficiency of the electron-hole pairs. In this work, novel Nb3O7F/CNTs hybrid nanocomposites with enhanced photocatalytic activity have been successfully synthesized by a facile hydrothermal plus etching technique. The important finding is that appropriate pH values lead to the formation of Nb3O7F nanocrystal directly. A general strategy to introdue interaction between Nb3O7F and CNTs markedly enhances the photocatalytic activity of Nb3O7F. Comparatively, Nb3O7F/CNTs nanocomposites exhibit higher photodegradation efficiency and faster photodegradation rate in the solution of methylene blue (MB) under visible-light irradiation. The higher photocatalytic activity may be attributed to more exposed active sites, higher carrier migration and narrower bandgap because of good synergistic effect. The results here may inspire more engineering, new design and facile fabrication of novel photocatalysts with highly photocatalytic activity. PMID:28059123

  16. A modeling approach to direct interspecies electron transfer process in anaerobic transformation of ethanol to methane.

    PubMed

    Liu, Yiwen; Zhang, Yaobin; Zhao, Zhiqiang; Ngo, Huu Hao; Guo, Wenshan; Zhou, Junliang; Peng, Lai; Ni, Bing-Jie

    2017-01-01

    Recent studies have shown that direct interspecies electron transfer (DIET) plays an important part in contributing to methane production from anaerobic digestion. However, so far anaerobic digestion models that have been proposed only consider two pathways for methane production, namely, acetoclastic methanogenesis and hydrogenotrophic methanogenesis, via indirect interspecies hydrogen transfer, which lacks an effective way for incorporating DIET into this paradigm. In this work, a new mathematical model is specifically developed to describe DIET process in anaerobic digestion through introducing extracellular electron transfer as a new pathway for methane production, taking anaerobic transformation of ethanol to methane as an example. The developed model was able to successfully predict experimental data on methane dynamics under different experimental conditions, supporting the validity of the developed model. Modeling predictions clearly demonstrated that DIET plays an important role in contributing to overall methane production (up to 33 %) and conductive material (i.e., carbon cloth) addition would significantly promote DIET through increasing ethanol conversion rate and methane production rate. The model developed in this work will potentially enhance our current understanding on syntrophic metabolism via DIET.

  17. The removal efficiency of constructed wetlands filled with the zeolite-slag hybrid substrate for the rural landfill leachate treatment.

    PubMed

    He, Hailing; Duan, Zhiwei; Wang, Zhenqing; Yue, Bo

    2017-07-01

    The removal efficiencies of two horizontal subsurface flow constructed wetlands (HSSF CWs, down-flow (F1) and up-flow (F2)) filled with the zeolite-slag hybrid substrate for the rural landfill leachate treatment were investigated. The adsorption experiment was conducted to evaluate the potential of zeolite and slag as the wetland substrate. The effects of distance variations along the longitudinal profile of wetland bed on pollutant removal were assessed by sampling at four locations (inlet, outlet, 0.55 m, and 1.10 m from the inlet). During the operation time, the influent and effluent concentrations of chemical oxygen demand (COD), ammonia nitrogen (NH 3 -N), total nitrogen (TN), heavy metals, and polycyclic aromatic hydrocarbon (PAH) were measured. The results showed that the constructed wetlands were capable of removing COD, 20.5-48.2% (F1) and 18.6-61.2% (F2); NH 3 -N, 84.0-99.9% (F1) and 93.5-99.2% (F2); TN, 80.3-92.1% (F1) and 80.3-91.2% (F2); and heavy metals, about 90% (F1 and F2). The zeolite-slag hybrid substrate performed excellent removal efficiency for the nitrogen and heavy metals. The inlet area was the most active region of leachate removal. The up-flow constructed wetland (F2) has a higher removal efficiency for the PAH compounds. The significant removal efficiency illustrated that the rural landfill leachate can be treated using the horizontal subsurface flow constructed wetland filled with the zeolite-slag hybrid substrate.

  18. Structural and electronic properties of U{sub n}O{sub m} (n=1-3,m=1-3n) clusters: A theoretical study using screened hybrid density functional theory

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

    Yang, Yu; Liu, Haitao; Zhang, Ping, E-mail: zhang-ping@iapcm.ac.cn

    The structural and electronic properties of small uranium oxide clusters U{sub n}O{sub m} (n=1-3, m=1-3n) are systematically studied within the screened hybrid density functional theory. It is found that the formation of U–O–U bondings and isolated U–O bonds are energetically more stable than U–U bondings. As a result, no uranium cores are observed. Through fragmentation studies, we find that the U{sub n}O{sub m} clusters with the m/n ratio between 2 and 2.5 are very stable, hinting that UO{sub 2+x} hyperoxides are energetically stable. Electronically, we find that the O-2p states always distribute in the deep energy range, and the U-5fmore » states always distribute at the two sides of the Fermi level. The U-6d states mainly hybridize with the U-5f states in U-rich clusters, while hybridizing with O-2p states in O-rich clusters. Our work is the first one on the screened hybrid density functional theory level studying the atomic and electronic properties of the actinide oxide clusters.« less

  19. Exogenous selection rather than cytonuclear incompatibilities shapes asymmetrical fitness of reciprocal Arabidopsis hybrids.

    PubMed

    Muir, Graham; Ruiz-Duarte, Paola; Hohmann, Nora; Mable, Barbara K; Novikova, Polina; Schmickl, Roswitha; Guggisberg, Alessia; Koch, Marcus A

    2015-04-01

    Reciprocal crosses between species often display an asymmetry in the fitness of F1 hybrids. This pattern, referred to as isolation asymmetry or Darwin's corollary to Haldane's rule, is a general feature of reproductive isolation in plants, yet factors determining its magnitude and direction remain unclear. We evaluated reciprocal species crosses between two naturally hybridizing diploid species of Arabidopsis to assess the degree of isolation asymmetry at different postmating life stages. We found that pollen from Arabidopsis arenosa will usually fertilize ovules from Arabidopsis lyrata; the reverse receptivity being less complete. Maternal A. lyrata parents set more F1 hybrid seed, but germinate at lower frequency, reversing the asymmetry. As predicted by theory, A. lyrata (the maternal parent with lower seed viability in crosses) exhibited accelerated chloroplast evolution, indicating that cytonuclear incompatibilities may play a role in reproductive isolation. However, this direction of asymmetrical reproductive isolation is not replicated in natural suture zones, where delayed hybrid breakdown of fertility at later developmental stages, or later-acting selection against A. arenosa maternal hybrids (unrelated to hybrid fertility, e.g., substrate adaptation) may be responsible for an excess of A. lyrata maternal hybrids. Exogenous selection rather than cytonuclear incompatibilities thus shapes the asymmetrical postmating isolation in nature.

  20. Meiotic Sex Chromosome Inactivation Is Disrupted in Sterile Hybrid Male House Mice

    PubMed Central

    Campbell, Polly; Good, Jeffrey M.; Nachman, Michael W.

    2013-01-01

    In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid male sterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis. PMID:23307891

  1. Meiotic sex chromosome inactivation is disrupted in sterile hybrid male house mice.

    PubMed

    Campbell, Polly; Good, Jeffrey M; Nachman, Michael W

    2013-03-01

    In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid male sterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis.

  2. Flexible graphene/carbon nanotube hybrid papers chemical-reduction-tailored by gallic acid for high-performance electrochemical capacitive energy storages

    NASA Astrophysics Data System (ADS)

    Yao, Lu; Zhou, Chao; Hu, Nantao; Hu, Jing; Hong, Min; Zhang, Liying; Zhang, Yafei

    2018-03-01

    Mechanically robust graphene papers with both high gravimetric and volumetric capacitances are desired for high-performance energy storages. However, it's still a challenge to tailor the structure of graphene papers in order to meet this requirement. In this work, a kind of chemical-reduction-tailored mechanically-robust reduced graphene oxide/carbon nanotube hybrid paper has been reported for high-performance electrochemical capacitive energy storages. Gallic acid (GA), as an excellent reducing agent, was used to reduce graphene oxide. Through vacuum filtration of gallic acid reduced graphene oxide (GA-rGO) and carboxylic multiwalled carbon nanotubes (MWCNTs) aqueous suspensions, mechanically robust GA-rGO/MWCNTs hybrid papers were obtained. The resultant hybrid papers showed high gravimetric capacitance of 337.6 F g-1 (0.5 A g-1) and volumetric capacitance of 151.2 F cm-3 (0.25 A cm-3). In addition, the assembled symmetric device based on the hybrid papers exhibited high gravimetric capacitance of 291.6 F g-1 (0.5 A g-1) and volumetric capacitance of 136.6 F cm-3 (0.25 A cm-3). Meanwhile, it exhibited excellent rate capability and cycling stability. Above all, this chemical reduction tailoring technique and the resultant high-performance GA-rGO/MWCNTs hybrid papers give an insight for designing high-performance electrodes and hold a great potential in the field of energy storages.

  3. Expression of the Retrotransposon Helena Reveals a Complex Pattern of TE Deregulation in Drosophila Hybrids

    PubMed Central

    Romero-Soriano, Valèria; Garcia Guerreiro, Maria Pilar

    2016-01-01

    Transposable elements (TEs), repeated mobile sequences, are ubiquitous in the eukaryotic kingdom. Their mobilizing capacity confers on them a high mutagenic potential, which must be strongly regulated to guarantee genome stability. In the Drosophila germline, a small RNA-mediated silencing system, the piRNA (Piwi-interacting RNA) pathway, is the main responsible TE regulating mechanism, but some stressful conditions can destabilize it. For instance, during interspecific hybridization, genomic stress caused by the shock of two different genomes can lead, in both animals and plants, to higher transposition rates. A recent study in D. buzatii—D. koepferae hybrids detected mobilization of 28 TEs, yet little is known about the molecular mechanisms explaining this transposition release. We have characterized one of the mobilized TEs, the retrotransposon Helena, and used quantitative expression to assess whether its high transposition rates in hybrids are preceded by increased expression. We have also localized Helena expression in the gonads to see if cellular expression patterns have changed in the hybrids. To give more insight into changes in TE regulation in hybrids, we analysed Helena-specific piRNA populations of hybrids and parental species. Helena expression is not globally altered in somatic tissues, but male and female gonads have different patterns of deregulation. In testes, Helena is repressed in F1, increasing then its expression up to parental values. This is linked with a mislocation of Helena transcripts along with an increase of their specific piRNA levels. Ovaries have additive levels of Helena expression, but the ping-pong cycle efficiency seems to be reduced in F1 hybrids. This could be at the origin of new Helena insertions in hybrids, which would be transmitted to F1 hybrid female progeny. PMID:26812285

  4. Vegetative and adaptive traits predict different outcomes for restoration using hybrids

    Treesearch

    Philip A. Crystal; Nathanael I. Lichti; Keith E. Woeste; Douglass F. Jacobs

    2016-01-01

    Hybridization has been implicated as a driver of speciation, extinction, and invasiveness, but can also provide resistant breeding stock following epidemics. However, evaluating the appropriateness of hybrids for use in restoration programs is difficult. Past the F1 generation, the proportion of a progenitor’s genome can vary widely, as can the combinations of parental...

  5. Genetic origin and composition of a natural hybrid poplar Populus × jrtyschensis from two distantly related species.

    PubMed

    Jiang, Dechun; Feng, Jianju; Dong, Miao; Wu, Guili; Mao, Kangshan; Liu, Jianquan

    2016-04-18

    The factors that contribute to and maintain hybrid zones between distinct species are highly variable, depending on hybrid origins, frequencies and fitness. In this study, we aimed to examine genetic origins, compositions and possible maintenance of Populus × jrtyschensis, an assumed natural hybrid between two distantly related species. This hybrid poplar occurs mainly on the floodplains along the river valleys between the overlapping distributions of the two putative parents. We collected 566 individuals from 45 typical populations of P. × jrtyschensis, P. nigra and P. laurifolia. We genotyped them based on the sequence variations of one maternally inherited chloroplast DNA (cpDNA) fragment and genetic polymorphisms at 20 SSR loci. We further sequenced eight nuclear genes for 168 individuals from 31 populations. Two groups of cpDNA haplotypes characteristic of P. nigra and P. laurifolia respectively were both recovered for P. × jrtyschensis. Genetic structures and coalescent tests of two sets of nuclear population genetic data suggested that P. × jrtyschensis originated from hybridizations between the two assumed parental species. All examined populations of P. × jrtyschensis comprise mainly F1 hybrids from interspecific hybridizations between P. nigra and P. laurifolia. In the habitats of P. × jrtyschensis, there are lower concentrations of soil nitrogen than in the habitats occupied by the other two species. Our extensive examination of the genetic composition of P. × jrtyschensis suggested that it is typical of F1-dominated hybrid zones. This finding plus the low concentration of soil nitrogen in the floodplain soils support the F1-dominated bounded hybrid superiority hypothesis of hybrid zone maintenance for this particular hybrid poplar.

  6. Widespread interspecies homologous recombination reveals reticulate evolution within the genus Streptomyces.

    PubMed

    Cheng, Kun; Rong, Xiaoying; Huang, Ying

    2016-09-01

    Homologous recombination is increasingly being recognized as a driving force in microbial evolution. However, recombination in streptomycetes, a rich source of diverse secondary metabolites, particularly among different species, remains minimally investigated. In this study, the largest sample of Streptomyces species to date, consisting of 142 type strains spanning the genus, with available sequences of 16S rRNA, atpD, gyrB, recA, rpoB and trpB genes, were collected and subjected to a comprehensive population genetic analysis to generate an overall estimate of the level of Streptomyces interspecies genetic exchange and its effect on the evolution of this genus. The results indicate frequent homologous recombination among Streptomyces species, which occurred three times more frequently and was nearly 14 times more important than point mutation in nucleotide sequence divergence (ρ/θw=3.10, r/m=13.74). As a result, a facilitating effect on the evolutionary process and confusion in phylogenetic relationships were observed, as well as a number of specific transfer events of the six gene fragments. A resultant phylogenetic network depicted extensive horizontal genetic exchange which decays clonality in streptomycetes. Moreover, seven evolutionary lineage groups were identified in the present sample in the Structure analysis, generally consistent with morphological and physiological data, and the contribution of recombination was detected to be varied among them. Our analyses demonstrated a reticulate evolution within Streptomyces due to the high level of interspecies gene exchange, which greatly challenges the traditional tree-shaped phylogeny in this genus and may advance our evolutionary understanding of a genuine Streptomyces species. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. A biomimetic nano hybrid coating based on the lotus effect and its anti-biofouling behaviors

    NASA Astrophysics Data System (ADS)

    Li, Jiang; Wang, Guoqing; Meng, Qinghua; Ding, Chunhua; Jiang, Hong; Fang, Yongzeng

    2014-10-01

    To develop an environmentally friendly anti-biofouling coating in virtue of bionics, a block copolymer containing fluorine (Coplm_F) of low surface energy was prepared by copolymerization. The Ag-loaded mesoporous silica (Ag@SBA) acting as a controlled-release antifoulant was prepared from the mesoporous silica (SBA-15). The nano hybrid coating (Ag@SBA/Coplm_F) composing of the Coplm_F and Ag@SBA was to biomimetically simulate the lotus microstructure. The concentration of fluorine element on surface was analyzed by the energy dispersive spectroscopy (EDS) and found rising to 1.45% after hybridation, which could be explained by the driving effect of SBA-15 via the hydrogen bond. This nanoscale morphology of the hybrid coating was measured and found highly semblable to the microstructure of the lotus surface. The contact angle was determined as 151° which confirmed the superhydrophobicity and lotus effect. The adhesion behaviors of Pseudomonas fluorescens, Diatoms, and Chlorella on the surface of the nano hybrid coating (Ag@SBA/Coplm_F) were studied and good effects of anti-biofouling were observed.

  8. Meat quality parameters of descendants by grading hybridization of Boer goat and Guanzhong Dairy goat.

    PubMed

    Ding, W; Kou, L; Cao, B; Wei, Y

    2010-03-01

    Chemical composition, cholesterol levels, fatty acid profile, meat taste, and quality parameters were evaluated in 48 buck kids from goats of the Guanzhong Dairy breed (Group G) and their crosses (Group F1: 1/2 Boermale symbolx1/2 Guanzhong Dairyfemale symbol; Group F2: 3/4 Boermale symbolx1/4 Guanzhong Dairyfemale symbol; Group F3: 7/8 Boermale symbolx1/8 Guanzhong Dairyfemale symbol) at different ages of slaughter (6, 8 and 10 months). Results indicated that grading hybridization (P<0.05) affected meat nutritive value. The muscle of hybrid goats had lower crude fat and cholesterol, higher crude protein, and greater proportion of C18:2 and C18:3 than that of Group G at each age. Group F1 goats had better (P<0.05) desirable fatty acid (DFA) and polyunsaturated fatty acid (PUFA) to saturated fatty acid (SFA) ratios and greater (C18:0+C18:1/C16:0) ratios (P<0.01) than those of the other genotypes. Furthermore, the muscles of hybrid goats were tenderer and juicier compared to Group G. In all four groups, cholesterol levels increased (P<0.01), muscle color became redder (P<0.05) and tenderness decreased (P<0.05) with increasing age. The low level of lipids and cholesterol, good meat quality, and the higher ratio of unsaturated to SFA in Group F1 indicate better quality for human consumption. Copyright 2009. Published by Elsevier Ltd.

  9. Nicotine Enhances Interspecies Relationship between Streptococcus mutans and Candida albicans.

    PubMed

    Liu, Shiyu; Qiu, Wei; Zhang, Keke; Zhou, Xuedong; Ren, Biao; He, Jinzhi; Xu, Xin; Cheng, Lei; Li, Mingyun

    2017-01-01

    Streptococcus mutans and Candida albicans are common microorganisms in the human oral cavity. The synergistic relationship between these two species has been deeply explored in many studies. In the present study, the effect of alkaloid nicotine on the interspecies between S. mutans and C. albicans is explored. We developed a dual-species biofilm model and studied biofilm biomass, biofilm structure, synthesis of extracellular polysaccharides (EPS), and expression of glucosyltransferases (Gtfs). Biofilm formation and bacterial and fungal cell numbers in dual-species biofilms increased in the presence of nicotine. More C. albicans cells were present in the dual-species biofilms in the nicotine-treated groups as determined by scanning electron microscopy. The synthesis of EPS was increased by 1 mg/ml of nicotine as detected by confocal laser scanning microscopy. The result of qRT-PCR showed gtfs expression was upregulated when 1 mg/ml of nicotine was used. We speculate that nicotine promoted the growth of S. mutans , and more S. mutans cells attracted more C. albicans cells due to the interaction between two species. Since S. mutans and C. albicans are putative pathogens for dental caries, the enhancement of the synergistic relationship by nicotine may contribute to caries development in smokers.

  10. Functional synergy between DP-1 and E2F-1 in the cell cycle-regulating transcription factor DRTF1/E2F.

    PubMed Central

    Bandara, L R; Buck, V M; Zamanian, M; Johnston, L H; La Thangue, N B

    1993-01-01

    It is widely believed that the cellular transcription factor DRTF1/E2F integrates cell cycle events with the transcription apparatus because during cell cycle progression in mammalian cells it interacts with molecules that are important regulators of cellular proliferation, such as the retinoblastoma tumour suppressor gene product (pRb), p107, cyclins and cyclin-dependent kinases. Thus, pRb, which negatively regulates early cell cycle progression and is frequently mutated in tumour cells, and the Rb-related protein p107, bind to and repress the transcriptional activity of DRTF1/E2F. Viral oncoproteins, such as adenovirus E1a and SV40 large T antigen, overcome such repression by sequestering pRb and p107 and in so doing are likely to activate genes regulated by DRTF1/E2F, such as cdc2, c-myc and DHFR. Two sequence-specific DNA binding proteins, E2F-1 and DP-1, which bind to the E2F site, contain a small region of similarity. The functional relationship between them has, however, been unclear. We report here that DP-1 and E2F-1 exist in a DNA binding complex in vivo and that they bind efficiently and preferentially as a heterodimer to the E2F site. Moreover, studies in yeast and Drosophila cells indicate that DP-1 and E2F-1 interact synergistically in E2F site-dependent transcriptional activation. Images PMID:8223441

  11. Hybrid incompatibilities in the parasitic wasp genus Nasonia: negative effects of hemizygosity and the identification of transmission ratio distortion loci

    PubMed Central

    Koevoets, T; Niehuis, O; van de Zande, L; Beukeboom, L W

    2012-01-01

    The occurrence of hybrid incompatibilities forms an important stage during the evolution of reproductive isolation. In early stages of speciation, males and females often respond differently to hybridization. Haldane's rule states that the heterogametic sex suffers more from hybridization than the homogametic sex. Although haplodiploid reproduction (haploid males, diploid females) does not involve sex chromosomes, sex-specific incompatibilities are predicted to be prevalent in haplodiploid species. Here, we evaluate the effect of sex/ploidy level on hybrid incompatibilities and locate genomic regions that cause increased mortality rates in hybrid males of the haplodiploid wasps Nasonia vitripennis and Nasonia longicornis. Our data show that diploid F1 hybrid females suffer less from hybridization than haploid F2 hybrid males. The latter not only suffer from an increased mortality rate, but also from behavioural and spermatogenic sterility. Genetic mapping in recombinant F2 male hybrids revealed that the observed hybrid mortality is most likely due to a disruption of cytonuclear interactions. As these sex-specific hybrid incompatibilities follow predictions based on Haldane's rule, our data accentuate the need to broaden the view of Haldane's rule to include species with haplodiploid sex determination, consistent with Haldane's original definition. PMID:21878985

  12. Hybrid incompatibilities in the parasitic wasp genus Nasonia: negative effects of hemizygosity and the identification of transmission ratio distortion loci.

    PubMed

    Koevoets, T; Niehuis, O; van de Zande, L; Beukeboom, L W

    2012-03-01

    The occurrence of hybrid incompatibilities forms an important stage during the evolution of reproductive isolation. In early stages of speciation, males and females often respond differently to hybridization. Haldane's rule states that the heterogametic sex suffers more from hybridization than the homogametic sex. Although haplodiploid reproduction (haploid males, diploid females) does not involve sex chromosomes, sex-specific incompatibilities are predicted to be prevalent in haplodiploid species. Here, we evaluate the effect of sex/ploidy level on hybrid incompatibilities and locate genomic regions that cause increased mortality rates in hybrid males of the haplodiploid wasps Nasonia vitripennis and Nasonia longicornis. Our data show that diploid F(1) hybrid females suffer less from hybridization than haploid F(2) hybrid males. The latter not only suffer from an increased mortality rate, but also from behavioural and spermatogenic sterility. Genetic mapping in recombinant F(2) male hybrids revealed that the observed hybrid mortality is most likely due to a disruption of cytonuclear interactions. As these sex-specific hybrid incompatibilities follow predictions based on Haldane's rule, our data accentuate the need to broaden the view of Haldane's rule to include species with haplodiploid sex determination, consistent with Haldane's original definition.

  13. Ephemeral association between gene CG5762 and hybrid male sterility in Drosophila sibling species.

    PubMed

    Ma, Daina; Michalak, Pawel

    2011-10-01

    Interspecies divergence in regulatory pathways may result in hybrid male sterility (HMS) when dominance and epistatic interactions between alleles that are functional within one genome are disrupted in hybrid genomes. The identification of genes contributing to HMS and other hybrid dysfunctions is essential for understanding the origin of new species (speciation). Previously, we identified a panel of male-specific loci misexpressed in sterile male hybrids of Drosophila simulans and D. mauritiana relative to parental species. In the current work, we attempt to dissect the genetic associations between HMS and one of the genes, CG5762, a Drosophila-unique locus characterized by rapid sequence divergence within the genus, presumably driven by positive natural selection. CG5762 is underexpressed in sterile backcross males compared with their fertile brothers. In CG5762 heterozygotes, the D. mauritiana allele is consistently overexpressed on both the D. simulans and D. mauritiana backcross genomic background, suggesting a cis-acting regulation factor. There is a significant association between heterozygosity and HMS in hybrid males from early but not later backcross generations. Microsatellite markers spanning CG5762 fail to associate with HMS. These observations lead to a conclusion that CG5762 is not a causative factor of HMS. Although genetic linkage between CG5762 and a neighboring causative introgression cannot be ruled out, it seems that the pattern is most consistent with CG5762 participating in epistatic interactions that are disrupted in flies with HMS.

  14. Flexible and freestanding supercapacitor based on nanostructured poly(m-aminophenol)/carbon nanofiber hybrid mats with high energy and power densities

    NASA Astrophysics Data System (ADS)

    Choudhury, Arup; Dey, Baban; Sinha Mahapatra, Susanta; Kim, Doo-Won; Yang, Kap-Seung; Yang, Duck-Joo

    2018-04-01

    Nanostructured poly(m-aminophenol) (PmAP) coated freestanding carbon nanofiber (CNF) mats were fabricated through simple in situ rapid-mixing polymerization of m-aminophenol in the presence of a CNF mat for flexible solid-state supercapacitors. The surface compositions, morphology and pore structure of the hybrid mats were characterized by using various techniques, e.g., FTIR, Raman, XRD, FE-SEM, TEM, and N2 absorption. The results show that the PmAP nanoparticles were homogeneously deposited on CNF surfaces and formed a thin flexible hybrid mat, which were directly used to made electrodes for electrochemical analysis without using any binders or conductive additives. The electrochemical performances of the hybrid mats were easily tailored by varying the PmAP loading on a hybrid electrode. The PmAP/CNF-10 hybrid electrode with a relatively low PmAP loading (> 42 wt%) showed a high specific capacitance of 325.8 F g-1 and a volumetric capacitance of 273.6 F cm-3 at a current density of 0.5 A g-1, together with a specific capacitance retention of 196.2 F g-1 at 20 A g-1. The PmAP/CNF-10 hybrid electrode showed good cycling stability with 88.2% capacitance retention after 5000 cycles. A maximum energy density of 45.2 Wh kg-1 and power density of 20.4 kW kg-1 were achieved for the PmAP/CNF-10 hybrid electrode. This facile and cost-effective synthesis of a flexible binder-free PmAP/CNF hybrid mat with excellent capacitive performances encourages its possible commercial exploitation.

  15. Syntrophic anaerobic photosynthesis via direct interspecies electron transfer

    PubMed Central

    Ha, Phuc T.; Lindemann, Stephen R.; Shi, Liang; Dohnalkova, Alice C.; Fredrickson, James K.; Madigan, Michael T.; Beyenal, Haluk

    2017-01-01

    Microbial phototrophs, key primary producers on Earth, use H2O, H2, H2S and other reduced inorganic compounds as electron donors. Here we describe a form of metabolism linking anoxygenic photosynthesis to anaerobic respiration that we call ‘syntrophic anaerobic photosynthesis'. We show that photoautotrophy in the green sulfur bacterium Prosthecochloris aestaurii can be driven by either electrons from a solid electrode or acetate oxidation via direct interspecies electron transfer from a heterotrophic partner bacterium, Geobacter sulfurreducens. Photosynthetic growth of P. aestuarii using reductant provided by either an electrode or syntrophy is robust and light-dependent. In contrast, P. aestuarii does not grow in co-culture with a G. sulfurreducens mutant lacking a trans-outer membrane porin-cytochrome protein complex required for direct intercellular electron transfer. Syntrophic anaerobic photosynthesis is therefore a carbon cycling process that could take place in anoxic environments. This process could be exploited for biotechnological applications, such as waste treatment and bioenergy production, using engineered phototrophic microbial communities. PMID:28067226

  16. An alternative pluripotent state confers interspecies chimaeric competency

    PubMed Central

    Wu, Jun; Okamura, Daiji; Li, Mo; Suzuki, Keiichiro; Luo, Chongyuan; Ma, Li; He, Yupeng; Li, Zhongwei; Benner, Chris; Tamura, Isao; Krause, Marie N.; Nery, Joseph R.; Du, Tingting; Zhang, Zhuzhu; Hishida, Tomoaki; Takahashi, Yuta; Aizawa, Emi; Kim, Na Young; Lajara, Jeronimo; Guillen, Pedro; Campistol, Josep M.; Esteban, Concepcion Rodriguez; Ross, Pablo J.; Saghatelian, Alan; Ren, Bing; Ecker, Joseph R.; Belmonte, Juan Carlos Izpisua

    2017-01-01

    Pluripotency, the ability to generate any cell type of the body, is an evanescent attribute of embryonic cells. Transitory pluripotent cells can be captured at different time points during embryogenesis and maintained as embryonic stem cells or epiblast stem cells in culture. Since ontogenesis is a dynamic process in both space and time, it seems counterintuitive that these two temporal states represent the full spectrum of organismal pluripotency. Here we show that by modulating culture parameters, a stem-cell type with unique spatial characteristics and distinct molecular and functional features, designated as region-selective pluripotent stem cells (rsPSCs), can be efficiently obtained from mouse embryos and primate pluripotent stem cells, including humans. The ease of culturing and editing the genome of human rsPSCs offers advantages for regenerative medicine applications. The unique ability of human rsPSCs to generate post-implantation interspecies chimaeric embryos may facilitate our understanding of early human development and evolution. PMID:25945737

  17. Nuclear and mitochondrial DNA analysis reveals that hybridization between Fasciola hepatica and Fasciola gigantica occurred in China.

    PubMed

    Ichikawa-Seki, Madoka; Peng, Mao; Hayashi, Kei; Shoriki, Takuya; Mohanta, Uday Kumar; Shibahara, Toshiyuki; Itagaki, Tadashi

    2017-02-01

    The well-known pathogens of fasciolosis, Fasciola hepatica (Fh) and Fasciola Gigantica (Fg), possess abundant mature sperms in their seminal vesicles, and thus, they reproduce bisexually. On the other hand, aspermic Fasciola flukes reported from Asian countries, which have no sperm in their seminal vesicles, probably reproduce parthenogenetically. The aim of this study was to reveal the origin of aspermic Fasciola flukes. The nuclear single copy markers, phosphoenolpyruvate carboxykinase and DNA polymerase delta, were employed for analysis of Fasciola species from China. The hybrid origin of aspermic Fasciola flukes was strongly suggested by the presence of the Fh/Fg type, which includes DNA fragments of both F. hepatica and F. gigantica. China can be regarded as the cradle of the interspecific hybridization because F. hepatica and F. gigantica were detected in the northern and southern parts of China, respectively, and hybrids flukes were distributed between the habitats of the two species. The Chinese origin was supported by the fact that a larger number of mitochondrial NADH dehydrogenase subunit 1 (nad1) haplotypes was detected in Chinese aspermic Fasciola populations than in aspermic populations from the neighbouring countries. Hereafter, 'aspermic' Fasciola flukes should be termed as 'hybrid' Fasciola flukes.

  18. Comparative studies of C3 and C4 Atriplex hybrids in the genomics era: physiological assessments

    PubMed Central

    Oakley, Jason C.; Sultmanis, Stefanie; Stinson, Corey R.; Sage, Tammy L.; Sage, Rowan F.

    2014-01-01

    We crossed the C3 species Atriplex prostrata with the C4 species Atriplex rosea to produce F1 and F2 hybrids. All hybrids exhibited C3-like δ13C values, and had reduced rates of net CO2 assimilation compared with A. prostrata. The activities of the major C4 cycle enzymes PEP carboxylase, NAD-malic enzyme, and pyruvate-Pi dikinase in the hybrids were at most 36% of the C4 values. These results demonstrate the C4 metabolic cycle was disrupted in the hybrids. Photosynthetic CO2 compensation points (Г) of the hybrids were generally midway between the C3 and C4 values, and in most hybrids were accompanied by low, C3-like activities in one or more of the major C4 cycle enzymes. This supports the possibility that most hybrids use a photorespiratory glycine shuttle to concentrate CO2 into the bundle sheath cells. One hybrid exhibited a C4-like Г of 4 µmol mol–1, indicating engagement of a C4 metabolic cycle. Consistently, this hybrid had elevated activities of all measured C4 cycle enzymes relative to the C3 parent; however, C3-like carbon isotope ratios indicate the low Г is mainly due to a photorespiratory glycine shuttle. The anatomy of the hybrids resembled that of C3-C4 intermediate species using a glycine shuttle to concentrate CO2 in the bundle sheath, and is further evidence that this physiology is the predominant, default condition of the F2 hybrids. Progeny of these hybrids should further segregate C3 and C4 traits and in doing so assist in the discovery of C4 genes using high-throughput methods of the genomics era. PMID:24675672

  19. Epitaxial growth of lithium fluoride on the (1 1 1) surface of CaF 2

    NASA Astrophysics Data System (ADS)

    Klumpp, St; Dabringhaus, H.

    1999-08-01

    Growth of lithium fluoride by molecular beam epitaxy on the (1 1 1) surface of calcium fluoride crystals was studied by TEM and LEED for crystal temperatures from 400 to 773 K and impinging lithium fluoride fluxes from 3×10 11 to 3×10 14 cm -2 s -1. Growth starts, usually, at the <1 1 0> steps on the (1 1 1) surface of CaF 2. For larger step distances and at later growth stages also growth on the terraces between the steps is found. Preferably, longish, roof-like crystallites are formed, which can be interpreted by growth of LiF(2 0 1¯)[0 1 0] parallel to CaF 2(1 1 1)[ 1¯ 0 1]. To a lesser extent square crystallites, i.e. growth with LiF(0 0 1), and, rarely, three-folded pyramidal crystallites, i.e. growth with LiF(1 1 1) parallel to CaF 2(1 1 1), are observed. While the pyramidal crystallites show strict epitaxial orientation with LiF[ 1¯ 0 1]‖CaF 2[ 1¯ 0 1] and LiF[ 1¯ 0 1]‖CaF 2[11], only about 80% of the square crystallites exhibit an epitaxial alignment, where LiF[1 0 0]‖CaF 2[ 1¯ 0 1] is preferred to LiF[1 1 0]‖CaF 2[ 1¯ 0 1]. The epitaxial relationships are discussed on the basis of theoretically calculated adsorption positions of the lithium fluoride monomer and dimer on the terrace and at the steps of the CaF 2(1 1 1) surface.

  20. Reproductive isolation in hybrid mice due to spermatogenesis defects at three meiotic stages.

    PubMed

    Oka, Ayako; Mita, Akihiko; Takada, Yuki; Koseki, Haruhiko; Shiroishi, Toshihiko

    2010-09-01

    Early in the process of speciation, reproductive failures occur in hybrid animals between genetically diverged populations. The sterile hybrid animals are often males in mammals and they exhibit spermatogenic disruptions, resulting in decreased number and/or malformation of mature sperms. Despite the generality of this phenomenon, comparative study of phenotypes in hybrid males from various crosses has not been done, and therefore the comprehensive genetic basis of the disruption is still elusive. In this study, we characterized the spermatogenic phenotype especially during meiosis in four different cases of reproductive isolation: B6-ChrX(MSM), PGN-ChrX(MSM), (B6 × Mus musculus musculus-NJL/Ms) F(1), and (B6 × Mus spretus) F(1). The first two are consomic strains, both bearing the X chromosome of M. m. molossinus; in B6-ChrX(MSM), the genetic background is the laboratory strain C57BL/6J (predominantly M. m. domesticus), while in PGN-ChrX(MSM) the background is the PGN2/Ms strain purely derived from wild M. m. domesticus. The last two cases are F(1) hybrids between mouse subspecies or species. Each of the hybrid males exhibited cell-cycle arrest and/or apoptosis at either one or two of three distinct meiotic stages: premeiotic stage, zygotene-to-pachytene stage of prophase I, and metaphase I. This study shows that the sterility in hybrid males is caused by spermatogenic disruptions at multiple stages, suggesting that the responsible genes function in different cellular processes. Furthermore, the stages with disruptions are not correlated with the genetic distance between the respective parental strains.

  1. Genetic analysis of hybridization and introgression between wild mongoose and brown lemurs.

    PubMed

    Pastorini, Jennifer; Zaramody, Alphonse; Curtis, Deborah J; Nievergelt, Caroline M; Mundy, Nicholas I

    2009-02-05

    Hybrid zones generally represent areas of secondary contact after speciation. The nature of the interaction between genes of individuals in a hybrid zone is of interest in the study of evolutionary processes. In this study, data from nuclear microsatellites and mitochondrial DNA sequences were used to genetically characterize hybridization between wild mongoose lemurs (Eulemur mongoz) and brown lemurs (E. fulvus) at Anjamena in west Madagascar. Two segments of mtDNA have been sequenced and 12 microsatellite loci screened in 162 brown lemurs and mongoose lemurs. Among the mongoose lemur population at Anjamena, we identified two F1 hybrids (one also having the mtDNA haplotype of E. fulvus) and six other individuals with putative introgressed alleles in their genotype. Principal component analysis groups both hybrids as intermediate between E. mongoz and E. fulvus and admixture analyses revealed an admixed genotype for both animals. Paternity testing proved one F1 hybrid to be fertile. Of the eight brown lemurs genotyped, all have either putative introgressed microsatellite alleles and/or the mtDNA haplotype of E. mongoz. Introgression is bidirectional for the two species, with an indication that it is more frequent in brown lemurs than in mongoose lemurs. We conclude that this hybridization occurs because mongoose lemurs have expanded their range relatively recently. Introgressive hybridization may play an important role in the unique lemur radiation, as has already been shown in other rapidly evolving animals.

  2. Synthesis, characterization, and pharmacological studies of ferrocene-1H-1,2,3-triazole hybrids

    NASA Astrophysics Data System (ADS)

    Haque, Ashanul; Hsieh, Ming-Fa; Hassan, Syed Imran; Haque Faizi, Md. Serajul; Saha, Anannya; Dege, Necmi; Rather, Jahangir Ahmad; Khan, Muhammad S.

    2017-10-01

    A series of ferrocene-1H-1,2,3-triazole hybrids namely 1-(4-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (1), 1-(4,4‧-dinitro-2-biphenyl)-4-ferrocenyl-1H-1,2,3-triazole (2), 1-(3-chloro-4-fluorophenyl)-4-ferrocenyl-1H-1,2,3-triazole (3), 1-(4-bromophenyl)-4-ferrocenyl-1H-1,2,3-triazole (4) and 1-(2-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (5) were designed and synthesized by copper-catalyzed azide alkyne cycloaddition (CuAAC) reaction. All the new hybrids were characterized by microanalyses, NMR (1H and 13C), UV-vis, IR, ESI-MS and electrochemical techniques. Crystal structure of the compound (3) was solved by single crystal X-ray diffraction method. The structural (single crystal) and spectroscopic (UV-Vis. and IR) properties of the compound 3 have been analyzed and compared by complementary quantum modeling. Hybrids 1-5 exhibited low toxicity and demonstrated neuroprotective effect.

  3. Clinical perspectives of hybrid proton-fluorine magnetic resonance imaging and spectroscopy.

    PubMed

    Wolters, Martijn; Mohades, Seyede G; Hackeng, Tilman M; Post, Mark J; Kooi, Marianne E; Backes, Walter H

    2013-05-01

    The number of applications of fluorine 19 (19F) magnetic resonance (MR) imaging and spectroscopy in biomedical and clinical research is steadily growing. The 100% natural abundance of fluorine and its relatively high sensitivity for MR (83% to that of protons) make it an interesting nucleus for a wide range of MR applications. Fluorinated contrast media have a number of advantages over the conventionally used gadolinium-based or iron-based contrast agents. The absence of an endogenous fluorine background intensity in the human body facilitates reliable quantification of fluorinated contrast medium or drugs. Anatomy can be visualized separately with proton MR imaging, creating the application of hybrid hydrogen 1 (1H)/19F MR imaging. The availability of 2 channels (ie, the 1H and 19F channels) enables dual-targeted molecular imaging. Recently, novel developments have emerged on fluorine-based contrast media in preclinical studies and imaging techniques. The developments in fluorine MR seem promising for clinical applications, with contributions in therapy monitoring, assessment of lung function, angiography, and molecular imaging. This review outlines the translation from recent advances in preclinical MR imaging and spectroscopy to future perspectives of clinical hybrid 1H/19/F MR imaging applications.

  4. Inter-species competition-facilitation in stochastic riparian vegetation dynamics.

    PubMed

    Tealdi, Stefano; Camporeale, Carlo; Ridolfi, Luca

    2013-02-07

    Riparian vegetation is a highly dynamic community that lives on river banks and which depends to a great extent on the fluvial hydrology. The stochasticity of the discharge and erosion/deposition processes in fact play a key role in determining the distribution of vegetation along a riparian transect. These abiotic processes interact with biotic competition/facilitation mechanisms, such as plant competition for light, water, and nutrients. In this work, we focus on the dynamics of plants characterized by three components: (1) stochastic forcing due to river discharges, (2) competition for resources, and (3) inter-species facilitation due to the interplay between vegetation and fluid dynamics processes. A minimalist stochastic bio-hydrological model is proposed for the dynamics of the biomass of two vegetation species: one species is assumed dominant and slow-growing, the other is subdominant, but fast-growing. The stochastic model is solved analytically and the probability density function of the plant biomasses is obtained as a function of both the hydrologic and biologic parameters. The impact of the competition/facilitation processes on the distribution of vegetation species along the riparian transect is investigated and remarkable effects are observed. Finally, a good qualitative agreement is found between the model results and field data. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Validation and Application of Pharmacokinetic Models for Interspecies Extrapolations in Toxicity Risk Assessments of Volatile Organics

    DTIC Science & Technology

    1988-08-30

    Ai _.. ;:: -- I. OVERALL OBJECTIVE AND STATEMENT OF WORK The overall objective of the proposed project is to investigate the scientific basis...development and inter-species correlations with toxicity. A second series of tissue disposition experiments will be conducted to determine what ...elimination of halocarbons is hepatic metabolism. If metabolism plays a significant role in the disposition and subsequent neurobehavioral effects of

  6. Hierarchical porous carbon/MnO2 hybrids as supercapacitor electrodes.

    PubMed

    Lee, Min Eui; Yun, Young Soo; Jin, Hyoung-Joon

    2014-12-01

    Hybrid electrodes of hierarchical porous carbon (HPC) and manganese oxide (MnO2) were synthesized using a fast surface redox reaction of potassium permanganate under facile immersion methods. The HPC/MnO2 hybrids had a number of micropores and macropores and the MnO2 nanoparticles acted as a pseudocapacitive material. The synergistic effects of electric double-layer capacitor (EDLC)-induced capacitance and pseudocapacitance brought about a better electrochemical performance of the HPC/MnO2 hybrid electrodes compared to that obtained with a single component. The hybrids showed a specific capacitance of 228 F g(-1) and good cycle stability over 1000 cycles.

  7. Enhanced supercapacitance of activated vertical graphene nanosheets in hybrid electrolyte

    NASA Astrophysics Data System (ADS)

    Ghosh, Subrata; Sahoo, Gopinath; Polaki, S. R.; Krishna, Nanda Gopala; Kamruddin, M.; Mathews, Tom

    2017-12-01

    Supercapacitors are becoming the workhorse for emerging energy storage applications due to their higher power density and superior cycle life compared to conventional batteries. The performance of supercapacitors depends on the electrode material, type of electrolyte, and interaction between them. Owing to the beneficial interconnected porous structure with multiple conducting channels, vertical graphene nanosheets (VGN) have proved to be leading supercapacitor electrode materials. Herein, we demonstrate a novel approach based on the combination of surface activation and a new organo-aqueous hybrid electrolyte, tetraethylammonium tetrafluoroborate in H2SO4, to achieve significant enhancement in supercapacitor performance of VGN. As-synthesized VGN exhibits an excellent supercapacitance of 0.64 mF/cm2 in H2SO4. However, identification of a novel electrolyte for performance enhancement is the subject of current research. The present manuscript demonstrates the potential of the hybrid electrolyte in enhancing the areal capacitance (1.99 mF/cm2) with excellent retention (only 5.4% loss after 5000 cycles) and Coulombic efficiency (93.1%). In addition, a five-fold enhancement in the capacitance of VGNs (0.64 to 3.31 mF/cm2) with a reduced internal resistance is achieved by the combination of KOH activation and the hybrid electrolyte.

  8. Production of rhesus monkey cloned embryos expressing monomeric red fluorescent protein by interspecies somatic cell nuclear transfer

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

    Zhu, Hai-Ying; Kang, Jin-Dan; Li, Suo

    2014-02-21

    Highlights: • Rhesus monkey cells were electroporated with a plasmid containing mRFP1, and an mRFP1-expressing cell line was generated. • For the first time, mRFP1-expressing rhesus monkey cells were used as donor cells for iSCNT. • The effect of VPA on the development of embryos cloned using iSCNT was determined. - Abstract: Interspecies somatic cell nuclear transfer (iSCNT) is a promising method to clone endangered animals from which oocytes are difficult to obtain. Monomeric red fluorescent protein 1 (mRFP1) is an excellent selection marker for transgenically modified cloned embryos during somatic cell nuclear transfer (SCNT). In this study, mRFP-expressing rhesusmore » monkey cells or porcine cells were transferred into enucleated porcine oocytes to generate iSCNT and SCNT embryos, respectively. The development of these embryos was studied in vitro. The percentage of embryos that underwent cleavage did not significantly differ between iSCNT and SCNT embryos (P > 0.05; 71.53% vs. 80.30%). However, significantly fewer iSCNT embryos than SCNT embryos reached the blastocyst stage (2.04% vs. 10.19%, P < 0.05). Valproic acid was used in an attempt to increase the percentage of iSCNT embryos that developed to the blastocyst stage. However, the percentages of embryos that underwent cleavage and reached the blastocyst stage were similar between untreated iSCNT embryos and iSCNT embryos treated with 2 mM valproic acid for 24 h (72.12% vs. 70.83% and 2.67% vs. 2.35%, respectively). These data suggest that porcine-rhesus monkey interspecies embryos can be generated that efficiently express mRFP1. However, a significantly lower proportion of iSCNT embryos than SCNT embryos reach the blastocyst stage. Valproic acid does not increase the percentage of porcine-rhesus monkey iSCNT embryos that reach the blastocyst stage. The mechanisms underling nuclear reprogramming and epigenetic modifications in iSCNT need to be investigated further.« less

  9. Identification of putative methanol dehydrogenase (moxF) structural genes in methylotrophs and cloning of moxF genes from methylococcus capsulatus bath and Methylomonas albus BG8

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

    Stephens, R.L.; Haygood, M.G.; Lidstrom, M.E.

    An open-reading-frame fragment of a Methylobacterium sp. strain AM1 gene (moxF) encoding a portion of the methanol dehydrogenase structural protein has been used as a hybridization probe to detect similar sequences in a variety of methylotrophic bacteria. This hybridization was used to isolate clones containing putative moxF genes from two obligate methanotrophic bacteria, Methylococcus capsulatus Bath and Methylomonas albus BG8. The identity of these genes was confirmed in two ways. A T7 expression vector was used to produce methanol dehydrogenase protein in Escherichia coli from the cloned genes,a and in each case the protein was identified by immunoblotting with antiserummore » against the Methylomonas albus methanol dehydrogenase. In addition, a moxF mutant of Methylobacterium strain AM1 was complemented to a methanol-positive phenotype that partially restored methanol dehydrogenase activity, using broad-host-range plasmids containing the moxF genes from each methanotroph. The partial complementation of a moxF mutant in a facultative serine pathway methanol utilizer by moxF genes from type I and type X obligate methane utilizers suggests broad functional conservation of the methanol oxidation system among gram-negative methylotrophs.« less

  10. Eco-geographically divergent diploids, Caucasian clover (Trifolium ambiguum) and western clover (T. occidentale), retain most requirements for hybridization

    PubMed Central

    Williams, Warren M.; Verry, Isabelle M.; Ansari, Helal A.; Hussain, S. Wajid; Ullah, Ihsan; Williamson, Michelle L.; Ellison, Nicholas W.

    2011-01-01

    Background and Aims DNA sequence similarities and hybridization patterns in Trifolium (clovers) section Trifoliastrum suggest that rapid radiation from a common ancestral source led to this complex of diverse species distributed across Europe, western Asia and North Africa. Two of the most geographically and ecologically divergent of these species are the rhizomatous T. ambiguum from high altitudes in eastern Europe and western Asia and the stoloniferous T. occidentale from sea level in western Europe. Attempts were made to hybridize these species to ascertain whether, despite this separation, gene flow could be achieved, indicating the retention of the genetic factors necessary for hybridization. Methods Three F1 hybrids formed after embryo rescue were described, characterized by conventional and molecular cytogenetics, subjected to fertility tests and progeny generations were developed. Results and Conclusions Partially fertile hybrids between Trifolium ambiguum and T. occidentale were obtained for the first time. The F1 hybrids produced seeds after open-pollination, and also produced triploid progeny in backcrosses to T. occidentale from the functioning of unreduced gametes in the hybrids. These plants were fertile and produced progeny with T. occidentale and with T. repens. Meiotic chromosome pairing in the F1 showed six to eight bivalents per pollen mother cell, indicating pairing between the parental genomes. A chromosome-doubled form of one hybrid, produced using colchicine, showed some multivalents, indicative of interspecific chromosome pairing. The hybrid plants were robust and combined phenotypic characteristics of both species, having stolons, thick roots and a few rhizomes. Results show that despite separation by the entire breadth of Europe, the speciation process is incomplete, and these taxa have partially retained most of the genetic compatibilities needed for hybridization (possibly except for endosperm development, which was not tested). The

  11. High-performance Cu nanoparticles/three-dimensional graphene/Ni foam hybrid for catalytic and sensing applications

    NASA Astrophysics Data System (ADS)

    Zhu, Long; Guo, Xinli; Liu, Yuanyuan; Chen, Zhongtao; Zhang, Weijie; Yin, Kuibo; Li, Long; Zhang, Yao; Wang, Zengmei; Sun, Litao; Zhao, Yuhong

    2018-04-01

    A novel hybrid of Cu nanoparticles/three-dimensional graphene/Ni foam (Cu NPs/3DGr/NiF) was prepared by chemical vapor deposition, followed by a galvanic displacement reaction in Ni- and Cu-ion-containing salt solution through a one-step reaction. The as-prepared Cu NPs/3DGr/NiF hybrid is uniform, stable, recyclable and exhibits an extraordinarily high catalytic efficiency for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with a reduction rate constant K = 0.056 15 s-1, required time ˜30 s and excellent sensing properties for the non-enzymatic amperometric hydrogen peroxide (H2O2) with a linear range ˜50 μM-9.65 mM, response time ˜3 s, detection limit ˜1 μM. The results indicate that the as-prepared Cu NPs/3DGr/NiF hybrid can be used to replace expensive noble metals in catalysis and sensing applications.

  12. M2-F1 simulator cockpit

    NASA Technical Reports Server (NTRS)

    1963-01-01

    This early simulator of the M2-F1 lifting body was used for pilot training, to test landing techniques before the first ground tow attempts, and to test new control configurations after the first tow attempts and wind-tunnel tests. The M2-F1 simulator was limited in some ways by its analog simulator. It had only limited visual display for the pilot, as well. The wingless, lifting body aircraft design was initially conceived as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne

  13. Shoal Bass hybridization below Morgan Falls Dam.

    USGS Publications Warehouse

    Taylor, Andrew T.; Tringali, Michael D.; O'Rourke, Patrick M.; Long, James M.

    2018-01-01

    The shoal bass (Micropterus cataractae) is a sportfish endemic to the Apalachicola-Chattahoochee-Flint Basin of the southeastern United States. Introgression with several non-native congeners poses a pertinent threat to shoal bass conservation, particularly in the altered habitats of the Chattahoochee River. Our primary objective was to characterize hybridization in shoal bass populations near Atlanta, Georgia, including a population inhabiting Big Creek and another in the main stem Chattahoochee River below Morgan Falls Dam (MFD). A secondary objective was to examine the accuracy of phenotypic identifications below MFD based on a simplified suite of characters examined in the field. Fish were genotyped with 16 microsatellite DNA markers, and results demonstrated that at least four black bass species were involved in introgressive hybridization. Of 62 fish genotyped from Big Creek, 27% were pure shoal bass and 65% represented either F1 hybrids of shoal bass x smallmouth bass (M. dolomieu) or unidirectional backcrosses towards shoal bass. Of 29 fish genotyped below MFD and downstream at Cochran Shoals, 45% were pure shoal bass. Six hybrid shoal bass included both F1 hybrids and backcrosses with non-natives including Alabama bass (M. henshalli), spotted bass (M. punctulatus), and smallmouth bass. Shoal bass alleles comprised only 21% of the overall genomic composition in Big Creek and 31% below MFD (when combined with Cochran Shoals). Phenotypic identification below MFD resulted in an overall correct classification rate of 86% when discerning pure shoal bass from all other non-natives and hybrids. Results suggest that although these two shoal bass populations feature some of the highest introgression rates documented, only a fleeting opportunity may exist to conserve pure shoal bass in both populations. Continued supplemental stocking of pure shoal bass below MFD appears warranted to thwart increased admixture among multiple black bass taxa, and a similar stocking

  14. M2-F1 in flight

    NASA Technical Reports Server (NTRS)

    1965-01-01

    The M2-F1 Lifting Body is seen here under tow, high above Rogers Dry Lake near the Flight Research Center (later redesignated the Dryden Flight Research Center), Edwards, California. R. Dale Reed effectively advocated the project with the support of NASA research pilot Milt Thompson. Together, they gained the support of Flight Research Center Director Paul Bikle. After a six-month feasibility study, Bikle gave approval in the fall of 1962 for the M2-F1 to be built. The wingless, lifting body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Flight Research Center management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. These initial tests produced enough flight data about the M2-F1 to proceed with flights behind a NASA C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL

  15. Hybrid origin of Asian aspermic Fasciola flukes is confirmed by analyzing two single-copy genes, pepck and pold

    PubMed Central

    HAYASHI, Kei; ICHIKAWA-SEKI, Madoka; MOHANTA, Uday Kumar; SHORIKI, Takuya; CHAICHANASAK, Pannigan; ITAGAKI, Tadashi

    2017-01-01

    Nuclear gene markers, phosphoenolpyruvate carboxykinase (pepck) and DNA polymerase delta (pold), have been developed for precise discrimination of Fasciola flukes instead of internal transcribed spacer 1. In this study, these two genes of 730 Fasciola flukes from eight Asian countries were analyzed. The results were compared with their mitochondrial NADH dehydrogenase subunit 1 (nad1) lineages for obtaining a definitive evidence of the hybrid origin of aspermic Fasciola flukes. All the flukes categorized into the aspermic nad1 lineages possessed both the fragment patterns of F. hepatica and F. gigantica (mixed types) in pepck and/or pold. These findings provide clear evidence for the hybrid origin of aspermic Fasciola lineages and suggest that “aspermic Fasciola flukes” should hereafter be called “hybrid Fasciola flukes”. PMID:29187710

  16. Use of comparative genomics approaches to characterize interspecies differences in response to environmental chemicals: Challenges, opportunities, and research needs

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

    Burgess-Herbert, Sarah L., E-mail: sarah.burgess@alum.mit.edu; Euling, Susan Y.

    A critical challenge for environmental chemical risk assessment is the characterization and reduction of uncertainties introduced when extrapolating inferences from one species to another. The purpose of this article is to explore the challenges, opportunities, and research needs surrounding the issue of how genomics data and computational and systems level approaches can be applied to inform differences in response to environmental chemical exposure across species. We propose that the data, tools, and evolutionary framework of comparative genomics be adapted to inform interspecies differences in chemical mechanisms of action. We compare and contrast existing approaches, from disciplines as varied as evolutionarymore » biology, systems biology, mathematics, and computer science, that can be used, modified, and combined in new ways to discover and characterize interspecies differences in chemical mechanism of action which, in turn, can be explored for application to risk assessment. We consider how genetic, protein, pathway, and network information can be interrogated from an evolutionary biology perspective to effectively characterize variations in biological processes of toxicological relevance among organisms. We conclude that comparative genomics approaches show promise for characterizing interspecies differences in mechanisms of action, and further, for improving our understanding of the uncertainties inherent in extrapolating inferences across species in both ecological and human health risk assessment. To achieve long-term relevance and consistent use in environmental chemical risk assessment, improved bioinformatics tools, computational methods robust to data gaps, and quantitative approaches for conducting extrapolations across species are critically needed. Specific areas ripe for research to address these needs are recommended.« less

  17. Synthesis of clonality and polyploidy in vertebrate animals by hybridization between two sexual species.

    PubMed

    Choleva, Lukáš; Janko, Karel; De Gelas, Koen; Bohlen, Jörg; Šlechtová, Věra; Rábová, Marie; Ráb, Petr

    2012-07-01

    Because most clonal vertebrates have hybrid genomic constitutions, tight linkages are assumed among hybridization, clonality, and polyploidy. However, predictions about how these processes mechanistically relate during the switch from sexual to clonal reproduction have not been validated. Therefore, we performed a crossing experiment to test the hypothesis that interspecific hybridization per se initiated clonal diploid and triploid spined loaches (Cobitis) and their gynogenetic reproduction. We reared two F1 families resulting from the crossing of 14 pairs of two sexual species, and found their diploid hybrid constitution and a 1:1 sex ratio. While males were infertile, females produced unreduced nonrecombinant eggs (100%). Synthetic triploid females and males (96.3%) resulted in each of nine backcrossed families from eggs of synthesized diploid F1s fertilized by haploid sperm from sexual males. Five individuals (3.7%) from one backcross family were genetically identical to the somatic cells of the mother and originated via gynogenesis; the sperm of the sexual male only triggered clonal development of the egg. Our reconstruction of the evolutionary route from sexuality to clonality and polyploidy in these fish shows that clonality and gynogenesis may have been directly triggered by interspecific hybridization and that polyploidy is a consequence, not a cause, of clonality. © 2012 The Author(s).

  18. Misregulation of spermatogenesis genes in Drosophila hybrids is lineage-specific and driven by the combined effects of sterility and fast male regulatory divergence.

    PubMed

    Gomes, S; Civetta, A

    2014-09-01

    Hybrid male sterility is a common outcome of crosses between different species. Gene expression studies have found that a number of spermatogenesis genes are differentially expressed in sterile hybrid males, compared with parental species. Late-stage sperm development genes are particularly likely to be misexpressed, with fewer early-stage genes affected. Thus, a link has been posited between misexpression and sterility. A more recent alternative explanation for hybrid gene misexpression has been that it is independent of sterility and driven by divergent evolution of male-specific regulatory elements between species (faster male hypothesis). The faster male hypothesis predicts that misregulation of spermatogenesis genes should be independent of sterility and approximately the same in both hybrids, whereas sterility should only affect gene expression in sterile hybrids. To test the faster male hypothesis vs. the effect of sterility on gene misexpression, we analyse spermatogenesis gene expression in different species pairs of the Drosophila phylogeny, where hybrid male sterility occurs in only one direction of the interspecies cross (i.e. unidirectional sterility). We find significant differences among genes in misexpression with effects that are lineage-specific and caused by sterility or fast male regulatory divergence. © 2014 The Authors. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  19. Arginine-Ornithine Antiporter ArcD Controls Arginine Metabolism and Interspecies Biofilm Development of Streptococcus gordonii*♦

    PubMed Central

    Sakanaka, Akito; Kuboniwa, Masae; Takeuchi, Hiroki; Hashino, Ei; Amano, Atsuo

    2015-01-01

    Arginine is utilized by the oral inhabitant Streptococcus gordonii as a substrate of the arginine deiminase system (ADS), eventually producing ATP and NH3, the latter of which is responsible for microbial resistance to pH stress. S. gordonii expresses a putative arginine-ornithine antiporter (ArcD) whose function has not been investigated despite relevance to the ADS and potential influence on inter-bacterial communication with periodontal pathogens that utilize amino acids as a main energy source. Here, we generated an S. gordonii ΔarcD mutant to explore the role of ArcD in physiological homeostasis and bacterial cross-feeding. First, we confirmed that S. gordonii ArcD plays crucial roles for mediating arginine uptake and promoting bacterial growth, particularly under arginine-limited conditions. Next, metabolomic profiling and transcriptional analysis of the ΔarcD mutant revealed that deletion of this gene caused intracellular accumulation of ornithine leading to malfunction of the ADS and suppression of de novo arginine biosynthesis. The mutant strain also showed increased susceptibility to low pH stress due to reduced production of ammonia. Finally, accumulation of Fusobacterium nucleatum was found to be significantly decreased in biofilm formed by the ΔarcD mutant as compared with the wild-type strain, although ornithine supplementation restored fusobacterium biovolume in dual-species biofilms with the ΔarcD mutant and also enhanced single species biofilm development by F. nucleatum. Our results are the first direct evidence showing that S. gordonii ArcD modulates not only alkali and energy production but also interspecies interaction with F. nucleatum, thus initiating a middle stage of periodontopathic biofilm formation, by metabolic cross-feeding. PMID:26085091

  20. Common Coupled Fixed Point Theorems for Two Hybrid Pairs of Mappings under φ-ψ Contraction

    PubMed Central

    Handa, Amrish

    2014-01-01

    We introduce the concept of (EA) property and occasional w-compatibility for hybrid pair F : X × X → 2X and f : X → X. We also introduce common (EA) property for two hybrid pairs F, G : X → 2X and f, g : X → X. We establish some common coupled fixed point theorems for two hybrid pairs of mappings under φ-ψ contraction on noncomplete metric spaces. An example is also given to validate our results. We improve, extend and generalize several known results. The results of this paper generalize the common fixed point theorems for hybrid pairs of mappings and essentially contain fixed point theorems for hybrid pair of mappings. PMID:27340688

  1. Convergent evolution of Darwin's finches caused by introgressive hybridization and selection.

    PubMed

    Grant, Peter R; Grant, B Rosemary; Markert, Jeffrey A; Keller, Lukas F; Petren, K

    2004-07-01

    Between 1973 and 2003 mean morphological features of the cactus finch, Geospiza scandens, and the medium ground finch, G. fortis, populations on the Galápagos island of Daphne Major were subject to fluctuating directional selection. An increase in bluntness or robustness in the beak of G. scandens after 1990 can only partly be explained by selection. We use 16 microsatellite loci to test predictions of the previously proposed hypothesis that introgressive hybridization contributed to the trend, resulting in genes flowing predominantly from G. fortis to G. scandens. To identify F1 hybrids and backcrosses we use pedigrees where known, supplemented by the results of assignment tests based on 14 autosomal loci when parents were not known. We analyze changes in morphology and allelic composition in the two populations over a period of 15-20 years. With samples that included F1 hybrids and backcrosses, the G. scandens population became more similar to the G. fortis population both genetically and morphologically. Gene flow between species was estimated to be three times greater from G. fortis to G. scandens than in the opposite direction, resulting in a 20% reduction in the genetic difference between the species. Nevertheless, removing identified F1 hybrids and backcrosses from the total sample and reanalyzing the traits did not eliminate the convergence. The two species also converged in beak shape by 22.2% and in body size by 45.5%. A combination of introgressive hybridization and selection jointly provide the best explanation of convergence in morphology and genetic constitution under the changed ecological conditions following a major El Niño event in 1983. The study illustrates how species without postmating barriers to gene exchange can alternate between convergence and divergence when environmental conditions oscillate.

  2. Human and Rat ABC Transporter Efflux of Bisphenol A and Bisphenol A Glucuronide: Interspecies Comparison and Implications for Pharmacokinetic Assessment

    EPA Science Inventory

    Significant interspecies differences exist between human and rodent with respect to absorption, distribution, and excretion of bisphenol A (BPA) and its primary metabolite, BPA-glucuronide (BPA-G). ATP-Binding Cassette (ABC) transporter enzymes play important roles in these physi...

  3. Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

    PubMed Central

    Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

    2015-01-01

    The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

  4. Probing hybrid modified gravity by stellar motion around Galactic Center

    NASA Astrophysics Data System (ADS)

    Borka, D.; Capozziello, S.; Jovanović, P.; Borka Jovanović, V.

    2016-06-01

    We consider possible signatures for the so called hybrid gravity within the Galactic Central Parsec. This modified theory of gravity consists of a superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed à la Palatiniand can be easily reduced to an equivalent scalar-tensor theory. Such an approach is introduced in order to cure the shortcomings related to f(R) gravity, in general formulated either in metric or in metric-affine frameworks. Hybrid gravity allows to disentangle the further gravitational degrees of freedom with respect to those of standard General Relativity. The present analysis is based on the S2 star orbital precession around the massive compact dark object at the Galactic Center where the simulated orbits in hybrid modified gravity are compared with astronomical observations. These simulations result with constraints on the range of hybrid gravity interaction parameter ϕ0, showing that in the case of S2 star it is between -0.0009 and -0.0002. At the same time, we are also able to obtain the constraints on the effective mass parameter mϕ, and found that it is between -0.0034 and -0.0025 AU-1 for S2 star. Furthermore, the hybrid gravity potential induces precession of S2 star orbit in the same direction as General Relativity. In previous papers, we considered other types of extended gravities, like metric power law f(R)∝Rn gravity, inducing Yukawa and Sanders-like gravitational potentials, but it seems that hybrid gravity is the best among these models to explain different gravitational phenomena at different astronomical scales.

  5. Impacts of trout predation on fitness of sympatric sticklebacks and their hybrids.

    PubMed Central

    Vamosi, Steven M; Schluter, Dolph

    2002-01-01

    Predation may be a significant factor in the divergence of sympatric species although its role has been largely overlooked. This study examines the consequences of predation on the fitness of a pair of lacustrine stickleback species (Gasterosteus aculeatus complex) and their F(1) hybrids. Benthic sticklebacks are found in the littoral zone of lakes associated with vegetation and bare sediments, whereas limnetic sticklebacks spend most of their lives in the pelagic zone. The cutthroat trout (Oncorhynchus clarki) is a major predator of sticklebacks and the only other fish species native to lakes containing both benthic and limnetic species. In pond experiments we found that the addition of these predators primarily impacted the survival of limnetics. By contrast, benthic survival was unaffected by trout addition. The result was that relative survival of benthics and limnetics was reversed in the presence of trout. The presence of trout had no effect on the rank order of parent species growth rates, with benthics always growing faster than limnetics. F(1) hybrids survived poorly relative to benthics and limnetics and their growth rates were intermediate regardless of treatment. The results implicate predation by trout in the divergence of the species but not through increased vulnerability of F(1) hybrids. PMID:12028775

  6. Behavioral and spermatogenic hybrid male breakdown in Nasonia.

    PubMed

    Clark, M E; O'Hara, F P; Chawla, A; Werren, J H

    2010-03-01

    Several reproductive barriers exist within the Nasonia species complex, including allopatry, premating behavioral isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioral sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviors, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared with wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviorally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than nonfunctional sperm, is different from most described cases of hybrid male sterility, and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioral sterility, and indicate that Wolbachia-induced hybrid incompatibility has arisen early in species divergence, relative to behavioral sterility and spermatogenic infertility.

  7. Behavioural and spermatogenic hybrid male breakdown in Nasonia

    PubMed Central

    Clark, Michael E.; O’Hara, F. Patrick; Chawla, Ankur; Werren, John H.

    2010-01-01

    Several reproductive barriers exists within the Nasonia species complex, including allopatry, premating behavioural isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioural sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviours, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared to wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviourally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than non-functional sperm, is different from most described cases of hybrid male sterility and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioural sterility, and indicated that Wolbachia induced hybrid incompatibility has arisen early in species divergence, relative to behavioural sterility and spermatogenic infertility. PMID:20087395

  8. Direct Interspecies Electron Transfer in Anaerobic Digestion: A Review.

    PubMed

    Dubé, Charles-David; Guiot, Serge R

    2015-01-01

    Direct interspecies electrons transfer (DIET) is a syntrophic metabolism in which free electrons flow from one cell to another without being shuttled by reduced molecules such as molecular hydrogen or formate. As more and more microorganisms show a capacity for electron exchange, either to export or import them, it becomes obvious that DIET is a syntrophic metabolism that is much more present in nature than previously thought. This article reviews literature related to DIET, specifically in reference to anaerobic digestion. Anaerobic granular sludge, a biofilm, is a specialized microenvironment where syntrophic bacterial and archaeal organisms grow together in close proximity. Exoelectrogenic bacteria degrading organic substrates or intermediates need an electron sink and electrotrophic methanogens represent perfect partners to assimilate those electrons and produce methane. The granule extracellular polymeric substances by making the biofilm matrix more conductive, play a role as electrons carrier in DIET.

  9. Mandible shape in hybrid mice.

    PubMed

    Renaud, Sabrina; Alibert, Paul; Auffray, Jean-Christophe

    2009-09-01

    Hybridisation between closely related species is frequently seen as retarding evolutionary divergence and can also promote it by creating novel phenotypes due to new genetic combinations and developmental interactions. We therefore investigated how hybridisation affects the shape of the mouse mandible, a well-known feature in evo-devo studies. Parental groups corresponded to two strains of the European mouse sub-species Mus musculus domesticus and Mus musculus musculus. Parents and hybrids were bred in controlled conditions. The mandibles of F(1) hybrids are mostly intermediate between parental phenotypes as expected for a complex multigenic character. Nevertheless, a transgressive effect as well as an increased phenotypic variance characterise the hybrids. This suggests that hybridisation between the two subspecies could lead to a higher phenotypic variance due to complex interactions among the parental genomes including non-additive genetic effects. The major direction of variance is conserved, however, among hybrids and parent groups. Hybridisation may thus play a role in the production of original transgressive phenotypes occurring following pre-existing patterns of variance.

  10. Cornus × elwinortonii and Cornus × rutgersensis (Cornaceae), new names for two artificially produced hybrids of big-bracted dogwoods

    PubMed Central

    Mattera, Robert; Molnar, Thomas; Struwe, Lena

    2015-01-01

    Abstract Big-bracted dogwoods (Cornus sp.) are well-known plants in North America and eastern Asia where they occur as wild, generally spring-flowering understory trees. They are also popular ornamental landscape plants, and many economically important cultivars are propagated and sold across North America, Europe, and Asia. Starting in the late 1960s, Elwin Orton of Rutgers University in New Jersey (USA) utilized three geographically disjunct species of dogwoods, Cornus florida (eastern North America), Cornus nuttallii (western North America), and Cornus kousa (East Asia), in an extensive interspecific hybridization program. He was successful in developing the first-ever interspecific F1 hybrids of these species, several of which have become staple items in the ornamental nursery trade due to their enhanced ornamental qualities and resistance to diseases. The original F1 plants are still alive at Rutgers University. While they have been available for decades in horticultural commerce, the interspecific hybrid crosses were never formally described and their scientific hybrid names were never published. For the Cornus kousa × Cornus florida hybrids, the name Cornus ‘rutgersensis’ has been used on occasion in the horticultural trade, but without proper citation and description. Here, it is formally named Cornus × rutgersensis Mattera, T. Molnar, & Struwe, hybr. nov. For the Cornus kousa × Cornus nuttallii hybrids, no previous name has been used, and it is hereby named Cornus × elwinortonii Mattera, T. Molnar, & Struwe, hybr. nov. The need for providing scientific names for commonly used horticultural hybrids is discussed. Holotype material for both hybrid names was collected from the original F1 hybrids for full documentation, typification, and description. The comparative intermediate development of leaves, inflorescence structures, and fruit types of the hybrids and their parents is discussed and illustrated. Etymology, phenology, and cultivation aspects of

  11. Preferred site occupation of 3 d atoms in NixF e4 -xN (x =1 and 3) films revealed by x-ray absorption spectroscopy and magnetic circular dichroism

    NASA Astrophysics Data System (ADS)

    Takata, Fumiya; Ito, Keita; Takeda, Yukiharu; Saitoh, Yuji; Takanashi, Koki; Kimura, Akio; Suemasu, Takashi

    2018-02-01

    X-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism measurements were performed at the Ni and Fe L2 ,3 absorption edges for N ixF e4 -xN (x =1 and 3) epitaxial films. Spectral line-shape analysis and element-specific magnetic moment evaluations are presented. Shoulders at approximately 2 eV above the Ni L2 ,3 main peaks in the XAS spectrum of N i3FeN were interpreted to originate from hybridization of orbitals between Ni 3 d at face-centered (II) sites and N 2 p at body-centered sites, while such features were missing in NiF e3N film. Similar shoulders were observed at Fe L2 ,3 edges in both films. These results indicate that the orbitals of Ni atoms did not hybridize with those of N atoms in the NiF e3N film. Hence, Ni atoms preferentially occupied corner (I) sites, where the hybridization was weak because of the relatively long distance between Ni at I sites and N atoms. The relatively large magnetic moment deduced from sum-rule analysis of NiF e3N also showed a good agreement with the presence of Ni atoms at I sites.

  12. Pressure and temperature dependence of the Ce valence and c -f hybridization gap in Ce T2In5(T =Co ,Rh ,Ir ) heavy-fermion superconductors

    NASA Astrophysics Data System (ADS)

    Yamaoka, H.; Yamamoto, Y.; Schwier, E. F.; Honda, F.; Zekko, Y.; Ohta, Y.; Lin, J.-F.; Nakatake, M.; Iwasawa, H.; Arita, M.; Shimada, K.; Hiraoka, N.; Ishii, H.; Tsuei, K.-D.; Mizuki, J.

    2015-12-01

    Pressure- and temperature-induced changes in the Ce valence and c -f hybridization of the Ce115 superconductors have been studied systematically. Resonant x-ray-emission spectroscopy indicated that the increase of the Ce valence with pressure was significant for CeCoIn5, and moderate for CeIr (In0.925Cd0.075)5 . We found no abrupt change of the Ce valence in the Kondo regime for CeIr (In0.925Cd0.075)5 , which suggests that valence fluctuations are unlikely to mediate the superconductivity in this material. X-ray-diffraction results were consistent with the pressure-induced change in the Ce valence. High-resolution photoelectron spectroscopy revealed a temperature-dependent reduction of the spectral intensity at the Fermi level, indicating enhanced c -f hybridization on cooling.

  13. Live Animal Markets in Minnesota: A Potential Source for Emergence of Novel Influenza A Viruses and Interspecies Transmission

    PubMed Central

    Choi, Mary J.; Torremorell, Montserrat; Bender, Jeff B.; Smith, Kirk; Boxrud, David; Ertl, Jon R.; Yang, My; Suwannakarn, Kamol; Her, Duachi; Nguyen, Jennifer; Uyeki, Timothy M.; Levine, Min; Lindstrom, Stephen; Katz, Jacqueline M.; Jhung, Michael; Vetter, Sara; Wong, Karen K.; Sreevatsan, Srinand; Lynfield, Ruth

    2015-01-01

    Background. Live animal markets have been implicated in transmission of influenza A viruses (IAVs) from animals to people. We sought to characterize IAVs at 2 live animal markets in Minnesota to assess potential routes of occupational exposure and risk for interspecies transmission. Methods. We implemented surveillance for IAVs among employees, swine, and environment (air and surfaces) during a 12-week period (October 2012–January 2013) at 2 markets epidemiologically associated with persons with swine-origin IAV (variant) infections. Real-time reverse transcription polymerase chain reaction (rRT-PCR), viral culture, and whole-genome sequencing were performed on respiratory and environmental specimens, and serology on sera from employees at beginning and end of surveillance. Results. Nasal swabs from 11 of 17 (65%) employees tested positive for IAVs by rRT-PCR; 7 employees tested positive on multiple occasions and 1 employee reported influenza-like illness. Eleven of 15 (73%) employees had baseline hemagglutination inhibition antibody titers ≥40 to swine-origin IAVs, but only 1 demonstrated a 4-fold titer increase to both swine-origin and pandemic A/Mexico/4108/2009 IAVs. IAVs were isolated from swine (72/84), air (30/45), and pen railings (5/21). Whole-genome sequencing of 122 IAVs isolated from swine and environmental specimens revealed multiple strains and subtype codetections. Multiple gene segment exchanges among and within subtypes were observed, resulting in new genetic constellations and reassortant viruses. Genetic sequence similarities of 99%–100% among IAVs of 1 market customer and swine indicated interspecies transmission. Conclusions. At markets where swine and persons are in close contact, swine-origin IAVs are prevalent and potentially provide conditions for novel IAV emergence. PMID:26223994

  14. Live Animal Markets in Minnesota: A Potential Source for Emergence of Novel Influenza A Viruses and Interspecies Transmission.

    PubMed

    Choi, Mary J; Torremorell, Montserrat; Bender, Jeff B; Smith, Kirk; Boxrud, David; Ertl, Jon R; Yang, My; Suwannakarn, Kamol; Her, Duachi; Nguyen, Jennifer; Uyeki, Timothy M; Levine, Min; Lindstrom, Stephen; Katz, Jacqueline M; Jhung, Michael; Vetter, Sara; Wong, Karen K; Sreevatsan, Srinand; Lynfield, Ruth

    2015-11-01

    Live animal markets have been implicated in transmission of influenza A viruses (IAVs) from animals to people. We sought to characterize IAVs at 2 live animal markets in Minnesota to assess potential routes of occupational exposure and risk for interspecies transmission. We implemented surveillance for IAVs among employees, swine, and environment (air and surfaces) during a 12-week period (October 2012-January 2013) at 2 markets epidemiologically associated with persons with swine-origin IAV (variant) infections. Real-time reverse transcription polymerase chain reaction (rRT-PCR), viral culture, and whole-genome sequencing were performed on respiratory and environmental specimens, and serology on sera from employees at beginning and end of surveillance. Nasal swabs from 11 of 17 (65%) employees tested positive for IAVs by rRT-PCR; 7 employees tested positive on multiple occasions and 1 employee reported influenza-like illness. Eleven of 15 (73%) employees had baseline hemagglutination inhibition antibody titers ≥40 to swine-origin IAVs, but only 1 demonstrated a 4-fold titer increase to both swine-origin and pandemic A/Mexico/4108/2009 IAVs. IAVs were isolated from swine (72/84), air (30/45), and pen railings (5/21). Whole-genome sequencing of 122 IAVs isolated from swine and environmental specimens revealed multiple strains and subtype codetections. Multiple gene segment exchanges among and within subtypes were observed, resulting in new genetic constellations and reassortant viruses. Genetic sequence similarities of 99%-100% among IAVs of 1 market customer and swine indicated interspecies transmission. At markets where swine and persons are in close contact, swine-origin IAVs are prevalent and potentially provide conditions for novel IAV emergence. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Comparative expression analysis of POU4F1, POU4F2 and ISL1 in developing mouse cochleovestibular ganglion neurons

    PubMed Central

    Deng, Min; Yang, Hua; Xie, Xiaoling; Liang, Guoqing; Gan, Lin

    2014-01-01

    POU-homeodomain and LIM-homeodomain transcription factors are expressed in developing projection neurons within retina, inner ear, dorsal root ganglion, and trigeminal ganglion, and play synergistic roles in their differentiation and survival. Here, using immunohistochemistry, we present a comparative analysis of the spatiotemporal expression pattern of POU4F1, POU4F2, and ISL1 during the development of cochleovestibular ganglion (CVG) neurons in mouse inner ear. At early stages, when otic neurons are first detected in the otic epithelium (OE) and migrate into periotic mesenchyme to form the CVG, POU4F1 and ISL1 are co-expressed in a majority of the delaminated CVG neurons, which are marked by NEUROD1 expression, but POU4F1 is absent in the otic epithelium. The onset of POU4F2 expression starts after that of POU4F1 and ISL1, and is observed in the NEUROD1-negative, post-mitotic CVG neurons. When the CVG neurons innervate the vestibular and cochlear sensory organs, the expression of POU4F1, POU4F2, and ISL1 continues in both vestibular and spiral ganglion cells. Later in development, POU4F1 expression becomes down-regulated in a majority of spiral ganglion (SG) neurons and more neurons express POU4F2 expression while ISL1 expression is maintained. The differential as well as overlapping expression of POU4F1, POU4F2, and ISL1 combined with previous studies suggests possible functional interaction and regulatory relationship of these transcription factors in the development of inner ear neurons. PMID:24709358

  16. Near-term hybrid vehicle program, phase 1. Appendix D: Sensitivity analysis resport

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Parametric analyses, using a hybrid vehicle synthesis and economics program (HYVELD) are described investigating the sensitivity of hybrid vehicle cost, fuel usage, utility, and marketability to changes in travel statistics, energy costs, vehicle lifetime and maintenance, owner use patterns, internal combustion engine (ICE) reference vehicle fuel economy, and drive-line component costs and type. The lowest initial cost of the hybrid vehicle would be $1200 to $1500 higher than that of the conventional vehicle. For nominal energy costs ($1.00/gal for gasoline and 4.2 cents/kWh for electricity), the ownership cost of the hybrid vehicle is projected to be 0.5 to 1.0 cents/mi less than the conventional ICE vehicle. To attain this ownership cost differential, the lifetime of the hybrid vehicle must be extended to 12 years and its maintenance cost reduced by 25 percent compared with the conventional vehicle. The ownership cost advantage of the hybrid vehicle increases rapidly as the price of fuel increases from $1 to $2/gal.

  17. M2-F1 in flight

    NASA Technical Reports Server (NTRS)

    1964-01-01

    The M2-F1 Lifting Body is seen here under tow by an unseen C-47 at the NASA Flight Research Center (later redesignated the Dryden Flight Research Center), Edwards, California. The low-cost vehicle was the first piloted lifting body to be test flown. The lifting-body concept originated in the mid-1950s at the National Advisory Committee for Aeronautics' Ames Aeronautical Laboratory, Mountain View California. By February 1962, a series of possible shapes had been developed, and R. Dale Reed was working to gain support for a research vehicle. The wingless, lifting body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. These initial tests produced enough flight data about the M2-F1 to proceed with flights behind a NASA C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at

  18. Comparison of fumonisin contamination using HPLC and ELISA methods in bt and near-isogenic maize hybrids infested with European corn borer or western bean cutworm.

    PubMed

    Bowers, Erin; Hellmich, Richard; Munkvold, Gary

    2014-07-09

    Field trials were conducted from 2007 to 2010 to compare grain fumonisin levels among non-Bt maize hybrids and Bt hybrids with transgenic protection against manual infestations of European corn borer (ECB) and Western bean cutworm (WBC). HPLC and ELISA were used to measure fumonisin levels. Results of the methods were highly correlated, but ELISA estimates were higher. Bt hybrids experienced less insect injury, Fusarium ear rot, and fumonisin contamination compared to non-Bt hybrids. WBC infestation increased fumonisin content compared to natural infestation in non-Bt and hybrids expressing Cry1Ab protein in five of eight possible comparisons; in Cry1F hybrids, WBC did not impact fumonisins. These results indicate that WBC is capable of increasing fumonisin levels in maize. Under WBC infestation, Cry1F mitigated this risk more consistently than Cry1Ab or non-Bt hybrids. Transgenically expressed Bt proteins active against multiple lepidopteran pests can provide broad, consistent reductions in the risk of fumonisin contamination.

  19. A single major QTL controls expression of larval Cry1F resistance trait in Ostrinia nubilalis (Lepidoptera: Crambidae) and is independent of midgut receptor genes

    USDA-ARS?s Scientific Manuscript database

    European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is an introduced crop pest in North America that causes major damage to corn, and reduces yield of food, feed, and biofuel materials. Transgenic hybrid corn expressing the Bacillus thuringiensis (Bt) toxin Cry1F is highly lethal to O...

  20. Hierarchically porous carbon/polyaniline hybrid for use in supercapacitors.

    PubMed

    Joo, Min Jae; Yun, Young Soo; Jin, Hyoung-Joon

    2014-12-01

    A hierarchically porous carbon (HPC)/polyaniline (PANI) hybrid electrode was prepared by the polymerization of PANI on the surface of the HPC via rapid-mixing polymerization. The surface morphologies and chemical composition of the HPC/PANI hybrid electrode were characterized using transmission electron microscopy and X-ray photoelectron spectroscopy (XPS), respectively. The surface morphologies and XPS results for the HPC, PANI and HPC/PANI hybrids indicate that PANI is coated on the surface of HPC in the HPC/PANI hybrids which have two different nitrogen groups as a benzenoid amine (-NH-) peak and positively charged nitrogen (N+) peak. The electrochemical performances of the HPC/PANI hybrids were analyzed by performing cyclic voltammetry and galvanostatic charge-discharge tests. The HPC/PANI hybrids showed a better specific capacitance (222 F/g) than HPC (111 F/g) because of effect of pseudocapacitor behavior. In addition, good cycle stabilities were maintained over 1000 cycles.

  1. Analysis of influenza A viruses of subtype H1 from wild birds, turkeys and pigs in Germany reveals interspecies transmission events.

    PubMed

    Starick, Elke; Fereidouni, Sasan R; Lange, Elke; Grund, Christian; Vahlenkamp, Thomas; Beer, Martin; Harder, Timm C

    2011-07-01

    Despite considerable host species barriers, interspecies transmissions of influenza A viruses between wild birds, poultry and pigs have been demonstrated repeatedly. In particular, viruses of the subtypes H1 and H3 were transmitted between pigs and poultry, predominantly turkeys, in regions with a high population density of both species. The recovery of a swine influenza H1N1 virus from a turkey flock in Germany in 2009 prompted us to investigate molecularly the subtype H1 viruses recently detected in wild birds, pigs and poultry. The goal of this study was to investigate the relationship between H1N1 viruses originating from wild and domestic animals of Germany and to identify potential trans-species transmission or reassortment events. Hemagglutinin and neuraminidase gene or full-length genome sequences were generated from selected, current H1N1 viruses from wild birds, pigs and turkeys. Phylogenetic analyses were combined with genotyping and analyses of the deduced amino acid sequences with respect to biologically active sites. Antigenic relationships were assessed by hemagglutination inhibition reactions. Phylogenetic analysis of the hemagglutinin sequences showed that viruses from distinct H1 subgroups co-circulate among domestic animals and wild birds. In addition, these viruses comprised different genotypes and were distinguishable antigenically. An H1N1 virus isolated from a turkey farm in northern Germany in 2009 showed the highest similarity with the avian-like porcine H1N1 influenza viruses circulating in Europe since the late 1970s. The data demonstrate the genetic and antigenic heterogeneity of H1 viruses currently circulating in domestic and wild animals in Germany and points to turkeys as a possible bridge between avian and mammalian hosts. © 2011 Blackwell Publishing Ltd.

  2. Solvothermal indium fluoride chemistry: Syntheses and crystal structures of K{sub 5}In{sub 3}F{sub 14}, beta-(NH{sub 4}){sub 3}InF{sub 6} and [NH{sub 4}]{sub 3}[C{sub 6}H{sub 21}N{sub 4}]{sub 2}[In{sub 4}F{sub 21}

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

    Jayasundera, Anil C.A.; Goff, Richard J.; Li Yang

    2010-02-15

    The solvothermal syntheses and crystal structures of three indium fluorides are presented. K{sub 5}In{sub 3}F{sub 14} (1) and beta-(NH{sub 4}){sub 3}InF{sub 6} (2) are variants on known inorganic structure types chiolite and cryolite, respectively, with the latter exhibiting a complex and apparently novel structural distortion. [NH{sub 4}]{sub 3}[C{sub 6}H{sub 21}N{sub 4}]{sub 2}[In{sub 4}F{sub 21}] (3) represents a new hybrid composition displaying a unique trimeric metal fluoride building unit. - Graphical abstract: Solvothermal synthesis has been used to prepare three indium fluorides, including a novel hybrid material containing a unique [In{sub 3}F{sub 15}] trimer templated by tren.

  3. Drosophila Females Undergo Genome Expansion after Interspecific Hybridization

    PubMed Central

    Romero-Soriano, Valèria; Burlet, Nelly; Vela, Doris; Fontdevila, Antonio; Vieira, Cristina; García Guerreiro, María Pilar

    2016-01-01

    Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent. PMID:26872773

  4. X-y interactions underlie sperm head abnormality in hybrid male house mice.

    PubMed

    Campbell, Polly; Nachman, Michael W

    2014-04-01

    The genetic basis of hybrid male sterility in house mice is complex, highly polygenic, and strongly X linked. Previous work suggested that there might be interactions between the Mus musculus musculus X and the M. m. domesticus Y with a large negative effect on sperm head morphology in hybrid males with an F1 autosomal background. To test this, we introgressed the M. m. domesticus Y onto a M. m. musculus background and measured the change in sperm morphology, testis weight, and sperm count across early backcross generations and in 11th generation backcross males in which the opportunity for X-autosome incompatibilities is effectively eliminated. We found that abnormality in sperm morphology persists in M. m. domesticus Y introgression males, and that this phenotype is rescued by M. m. domesticus introgressions on the X chromosome. In contrast, the severe reductions in testis weight and sperm count that characterize F1 males were eliminated after one generation of backcrossing. These results indicate that X-Y incompatibilities contribute specifically to sperm morphology. In contrast, X-autosome incompatibilities contribute to low testis weight, low sperm count, and sperm morphology. Restoration of normal testis weight and sperm count in first generation backcross males suggests that a small number of complex incompatibilities between loci on the M. m. musculus X and the M. m. domesticus autosomes underlie F1 male sterility. Together, these results provide insight into the genetic architecture of F1 male sterility and help to explain genome-wide patterns of introgression across the house mouse hybrid zone.

  5. Syntrophic anaerobic photosynthesis via direct interspecies electron transfer

    DOE PAGES

    Ha, Phuc T.; Lindemann, Stephen R.; Shi, Liang; ...

    2017-01-09

    Microbial phototrophs, key primary producers on Earth, use H 2O, H 2, H 2S and other reduced inorganic compounds as electron donors. Here we describe a form of metabolism linking anoxygenic photosynthesis to anaerobic respiration that we call ‘syntrophic anaerobic photosynthesis’. We show that photoautotrophy in the green sulfur bacterium Prosthecochloris aestaurii can be driven by either electrons from a solid electrode or acetate oxidation via direct interspecies electron transfer from a heterotrophic partner bacterium, Geobacter sulfurreducens. Photosynthetic growth of P. aestuarii using reductant provided by either an electrode or syntrophy is robust and light-dependent. In contrast, P. aestuarii doesmore » not grow in co-culture with a G. sulfurreducens mutant lacking a trans-outer membrane porin-cytochrome protein complex required for direct intercellular electron transfer. Syntrophic anaerobic photosynthesis is therefore a carbon cycling process that could take place in anoxic environments. Lastly, this process could be exploited for biotechnological applications, such as waste treatment and bioenergy production, using engineered phototrophic microbial communities.« less

  6. Intra- and interspecies gene expression models for predicting drug response in canine osteosarcoma.

    PubMed

    Fowles, Jared S; Brown, Kristen C; Hess, Ann M; Duval, Dawn L; Gustafson, Daniel L

    2016-02-19

    Genomics-based predictors of drug response have the potential to improve outcomes associated with cancer therapy. Osteosarcoma (OS), the most common primary bone cancer in dogs, is commonly treated with adjuvant doxorubicin or carboplatin following amputation of the affected limb. We evaluated the use of gene-expression based models built in an intra- or interspecies manner to predict chemosensitivity and treatment outcome in canine OS. Models were built and evaluated using microarray gene expression and drug sensitivity data from human and canine cancer cell lines, and canine OS tumor datasets. The "COXEN" method was utilized to filter gene signatures between human and dog datasets based on strong co-expression patterns. Models were built using linear discriminant analysis via the misclassification penalized posterior algorithm. The best doxorubicin model involved genes identified in human lines that were co-expressed and trained on canine OS tumor data, which accurately predicted clinical outcome in 73 % of dogs (p = 0.0262, binomial). The best carboplatin model utilized canine lines for gene identification and model training, with canine OS tumor data for co-expression. Dogs whose treatment matched our predictions had significantly better clinical outcomes than those that didn't (p = 0.0006, Log Rank), and this predictor significantly associated with longer disease free intervals in a Cox multivariate analysis (hazard ratio = 0.3102, p = 0.0124). Our data show that intra- and interspecies gene expression models can successfully predict response in canine OS, which may improve outcome in dogs and serve as pre-clinical validation for similar methods in human cancer research.

  7. Inheritance of brewing-relevant phenotypes in constructed Saccharomyces cerevisiae × Saccharomyces eubayanus hybrids.

    PubMed

    Krogerus, Kristoffer; Seppänen-Laakso, Tuulikki; Castillo, Sandra; Gibson, Brian

    2017-04-21

    Interspecific hybridization has proven to be a potentially valuable technique for generating de novo lager yeast strains that possess diverse and improved traits compared to their parent strains. To further enhance the value of hybridization for strain development, it would be desirable to combine phenotypic traits from more than two parent strains, as well as remove unwanted traits from hybrids. One such trait, that has limited the industrial use of de novo lager yeast hybrids, is their inherent tendency to produce phenolic off-flavours; an undesirable trait inherited from the Saccharomyces eubayanus parent. Trait removal and the addition of traits from a third strain could be achieved through sporulation and meiotic recombination or further mating. However, interspecies hybrids tend to be sterile, which impedes this opportunity. Here we generated a set of five hybrids from three different parent strains, two of which contained DNA from all three parent strains. These hybrids were constructed with fertile allotetraploid intermediates, which were capable of efficient sporulation. We used these eight brewing strains to examine two brewing-relevant phenotypes: stress tolerance and phenolic off-flavour formation. Lipidomics and multivariate analysis revealed links between several lipid species and the ability to ferment in low temperatures and high ethanol concentrations. Unsaturated fatty acids, such as oleic acid, and ergosterol were shown to positively influence growth at high ethanol concentrations. The ability to produce phenolic off-flavours was also successfully removed from one of the hybrids, Hybrid T2, through meiotic segregation. The potential application of these strains in industrial fermentations was demonstrated in wort fermentations, which revealed that the meiotic segregant Hybrid T2 not only didn't produce any phenolic off-flavours, but also reached the highest ethanol concentration and consumed the most maltotriose. Our study demonstrates the

  8. Imaging Prostate Cancer Microenvironment by Collagen Hybridization

    DTIC Science & Technology

    2016-12-01

    2: Evaluation of 18F-DCFPyL labelling and tracking of PSMA+ CAR T cells Title: PSMA Directed Imaging of Prostate Cancer Focus on Androgen Receptor ... receptors to treat cancer Title: Plasmid Selection and Characterisation Time Commitments: 1.20 calendar months Supporting Agency: Cancer Targeting...AWARD NUMBER: W81XWH-12-1-0556 TITLE: Imaging Prostate Cancer Microenvironment by Collagen Hybridization PRINCIPAL INVESTIGATOR: Martin

  9. Congenital hypopituitarism due to POU1F1 gene mutation.

    PubMed

    Lee, Ni-Chung; Tsai, Wen-Yu; Peng, Shinn-Forng; Tung, Yi-Ching; Chien, Yin-Hsiu; Hwu, Wuh-Liang

    2011-01-01

    POU1F1 (Pit-1; Gene ID 5449) is an anterior pituitary transcriptional factor, and POU1F1 mutation is known to cause anterior pituitary hypoplasia, growth hormone and prolactin deficiency and various degree of hypothyroidism. We report here a patient who presented with growth failure and central hypothyroidism since early infancy. However, treatment with thyroxine gave no effect and he subsequently developed calf muscle pseudohypertrophy (Kocher-Debre-Semelaigne syndrome), elevation of creatinine kinase, dilated cardiomyopathy and pericardial effusion. Final diagnosis was made by combined pituitary function test and sequencing analysis that revealed POU1F1 gene C.698T > C (p.F233S) mutation. The rarity of the disease can result in delayed diagnosis and treatment. Copyright © 2011 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.

  10. A novel male sterility-fertility restoration system in plants for hybrid seed production

    PubMed Central

    Singh, Surendra Pratap; Singh, Sudhir P.; Pandey, Tripti; Singh, Ram Rakshpal; Sawant, Samir V.

    2015-01-01

    Hybrid seeds are used for stimulated crop production, as they harness heterosis. The achievement of complete male-sterility in the female-parent and the restored-fertility in F1-hybrids are the major bottlenecks in the commercial hybrid seed production. Here, we report a male sterility–fertility restoration system by engineering the inmost nutritive anther wall layer tapetum of female and male parents. In the female parent, high–level, and stringent expression of Arabidopsis autophagy–related gene BECLIN1 was achieved in the tapetum, which altered the tapetal degeneration program, leading to male sterility. This works on our previously demonstrated expression cassette based on functional complementation of TATA-box mutant (TGTA) promoter and TATA-binding protein mutant3 (TBPm3), with modification by conjugating Long Hypocotyle in Far-Red1 fragment (HFR1NT131) with TBPm3 (HFR1NT131-TBPm3) to exercise regulatory control over it. In the male parent, tapetum–specific Constitutive photo-morphogenesis1 (COP1) was expressed. The F1 obtained by crossing these engineered parents showed decreased BECLIN1 expression, which was further completely abolished when COP1-mutant (COP1L105A) was used as a male parent, leading to normal tapetal development and restored fertility. The system works on COP1-HFR1 interaction and COP1–mediated degradation of TBPm3 pool (HFR1NT131-TBPm3). The system can be deployed for hybrid seed production in agricultural crops. PMID:26073981

  11. A novel male sterility-fertility restoration system in plants for hybrid seed production.

    PubMed

    Singh, Surendra Pratap; Singh, Sudhir P; Pandey, Tripti; Singh, Ram Rakshpal; Sawant, Samir V

    2015-06-15

    Hybrid seeds are used for stimulated crop production, as they harness heterosis. The achievement of complete male-sterility in the female-parent and the restored-fertility in F1-hybrids are the major bottlenecks in the commercial hybrid seed production. Here, we report a male sterility-fertility restoration system by engineering the in most nutritive anther wall layer tapetum of female and male parents. In the female parent, high-level, and stringent expression of Arabidopsis autophagy-related gene BECLIN1 was achieved in the tapetum, which altered the tapetal degeneration program, leading to male sterility. This works on our previously demonstrated expression cassette based on functional complementation of TATA-box mutant (TGTA) promoter and TATA-binding protein mutant3 (TBPm3), with modification by conjugating Long Hypocotyle in Far-Red1 fragment (HFR1(NT131)) with TBPm3 (HFR1(NT131)-TBPm3) to exercise regulatory control over it. In the male parent, tapetum-specific Constitutive photo-morphogenesis1 (COP1) was expressed. The F1 obtained by crossing these engineered parents showed decreased BECLIN1 expression, which was further completely abolished when COP1-mutant (COP1(L105A)) was used as a male parent, leading to normal tapetal development and restored fertility. The system works on COP1-HFR1 interaction and COP1-mediated degradation of TBPm3 pool (HFR1(NT131)-TBPm3). The system can be deployed for hybrid seed production in agricultural crops.

  12. Simple Y-autosomal incompatibilities cause hybrid male sterility in reciprocal crosses between Drosophila virilis and D. americana.

    PubMed

    Sweigart, Andrea L

    2010-03-01

    Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F(1) hybrid males are perfectly fertile. Second, later generation (backcross and F(2)) hybrid male sterility between D. virilis and D. americana is not polygenic. In fact, I identified only three genetically independent incompatibilities that cause hybrid male sterility. Remarkably, each of these incompatibilities involves the Y chromosome. In one direction of the cross, the D. americana Y is incompatible with recessive D. virilis alleles at loci on chromosomes 2 and 5. In the other direction, the D. virilis Y chromosome causes hybrid male sterility in combination with recessive D. americana alleles at a single QTL on chromosome 5. Finally, in contrast with findings from other Drosophila species pairs, the X chromosome has only a modest effect on hybrid male sterility between D. virilis and D. americana.

  13. Simple Y-Autosomal Incompatibilities Cause Hybrid Male Sterility in Reciprocal Crosses Between Drosophila virilis and D. americana

    PubMed Central

    Sweigart, Andrea L.

    2010-01-01

    Postzygotic reproductive isolation evolves when hybrid incompatibilities accumulate between diverging populations. Here, I examine the genetic basis of hybrid male sterility between two species of Drosophila, Drosophila virilis and D. americana. From these analyses, I reach several conclusions. First, neither species carries any autosomal dominant hybrid male sterility alleles: reciprocal F1 hybrid males are perfectly fertile. Second, later generation (backcross and F2) hybrid male sterility between D. virilis and D. americana is not polygenic. In fact, I identified only three genetically independent incompatibilities that cause hybrid male sterility. Remarkably, each of these incompatibilities involves the Y chromosome. In one direction of the cross, the D. americana Y is incompatible with recessive D. virilis alleles at loci on chromosomes 2 and 5. In the other direction, the D. virilis Y chromosome causes hybrid male sterility in combination with recessive D. americana alleles at a single QTL on chromosome 5. Finally, in contrast with findings from other Drosophila species pairs, the X chromosome has only a modest effect on hybrid male sterility between D. virilis and D. americana. PMID:20048051

  14. Performance of hybrids between weedy rice and insect-resistant transgenic rice under field experiments: implication for environmental biosafety assessment.

    PubMed

    Cao, Qian-Jin; Xia, Hui; Yang, Xiao; Lu, Bao-Rong

    2009-12-01

    Transgene escape from genetically modified (GM) rice into weedy rice via gene flow may cause undesired environmental consequences. Estimating the field performance of crop-weed hybrids will facilitate our understanding of potential introgression of crop genes (including transgenes) into weedy rice populations, allowing for effective biosafety assessment. Comparative studies of three weedy rice strains and their hybrids with two GM rice lines containing different insect-resistance transgenes (CpTI or Bt/CpTI) indicated an enhanced relative performance of the crop-weed hybrids, with taller plants, more tillers, panicles, and spikelets per plant, as well as higher 1 000-seed weight, compared with the weedy rice parents, although the hybrids produced less filled seeds per plant than their weedy parents. Seeds from the F(1) hybrids had higher germination rates and produced more seedlings than the weedy parents, which correlated positively with 1 000-seed weight. The crop-weed hybrids demonstrated a generally enhanced relative performance than their weedy rice parents in our field experiments. These findings indicate that transgenes from GM rice can persist to and introgress into weedy rice populations through recurrent crop-to-weed gene flow with the aid of slightly increased relative fitness in F(1) hybrids.

  15. Hybrid NiS/CoO mesoporous nanosheet arrays on Ni foam for high-rate supercapacitors

    NASA Astrophysics Data System (ADS)

    Wu, Jianghong; Ouyang, Canbin; Dou, Shuo; Wang, Shuangyin

    2015-08-01

    A new hybrid of NiS/CoO porous nanosheets was synthesized on Ni foam by one-step electrodeposition method and used as an electrode for high-performance pseudocapacitance. The as-synthesized NiS/CoO porous nanosheets hybrid shows a high specific capacitance of 1054 F g-1 at a high current density of 6 A g-1, a good rate capability even at high current density (760 F g-1 at 20 A g-1) and a good long-term cycling stability (91.7% of the maximum specific capacitance after 3000 cycles). These excellent properties can be mainly attributed to the unique hierarchical porous structure with large surface area and interspaces which facilitate charge transfer and redox reaction. The enhancement in the interface contact between active material and substrate results in excellent conductivity of the electrode and a strong synergistic effect of NiS and CoO as individual constituents contributed to high capacitance of the hybrid electrode.

  16. Hybrid NiS/CoO mesoporous nanosheet arrays on Ni foam for high-rate supercapacitors.

    PubMed

    Wu, Jianghong; Ouyang, Canbin; Dou, Shuo; Wang, Shuangyin

    2015-08-14

    A new hybrid of NiS/CoO porous nanosheets was synthesized on Ni foam by one-step electrodeposition method and used as an electrode for high-performance pseudocapacitance. The as-synthesized NiS/CoO porous nanosheets hybrid shows a high specific capacitance of 1054 F g(-1) at a high current density of 6 A g(-1), a good rate capability even at high current density (760 F g(-1) at 20 A g(-1)) and a good long-term cycling stability (91.7% of the maximum specific capacitance after 3000 cycles). These excellent properties can be mainly attributed to the unique hierarchical porous structure with large surface area and interspaces which facilitate charge transfer and redox reaction. The enhancement in the interface contact between active material and substrate results in excellent conductivity of the electrode and a strong synergistic effect of NiS and CoO as individual constituents contributed to high capacitance of the hybrid electrode.

  17. Hybrid Propulsion Technology Program, phase 1. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The study program was contracted to evaluate concepts of hybrid propulsion, select the most optimum, and prepare a conceptual design package. Further, this study required preparation of a technology definition package to identify hybrid propulsion enabling technologies and planning to acquire that technology in Phase 2 and demonstrate that technology in Phase 3. Researchers evaluated two design philosophies for Hybrid Rocket Booster (HRB) selection. The first is an ASRM modified hybrid wherein as many components/designs as possible were used from the present Advanced Solid Rocket Motor (ASRM) design. The second was an entirely new hybrid optimized booster using ASRM criteria as a point of departure, i.e., diameter, thrust time curve, launch facilities, and external tank attach points. Researchers selected the new design based on the logic of optimizing a hybrid booster to provide NASA with a next generation vehicle in lieu of an interim advancement over the ASRM. The enabling technologies for hybrid propulsion are applicable to either and vehicle design may be selected at a downstream point (Phase 3) at NASA's discretion. The completion of these studies resulted in ranking the various concepts of boosters from the RSRM to a turbopump fed (TF) hybrid. The scoring resulting from the Figure of Merit (FOM) scoring system clearly shows a natural growth path where the turbopump fed solid liquid staged combustion hybrid provides maximized payload and the highest safety, reliability, and low life cycle costing.

  18. 1/f noise: diffusive systems and music

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

    Voss, R.F.

    1975-11-01

    Measurements of the 1/f voltage noise in continuous metal films are reported. At room temperature, samples of pure metals and bismuth (with a carrier density smaller by 10/sup 5/) of similar volume had comparable noise. The results suggest that the noise arises from equilibrium temperature fluctuations modulating the resistance. Spatial correlation of the noise implied that the fluctuations obey a diffusion equation. The empirical inclusion of an explicit 1/f region and appropriate normalization lead to excellent agreement with the measured noise. If the fluctuations are assumed to be spatially correlated, the diffusion equation can yield an extended 1/f region inmore » the power spectrum. The temperature response of a sample to delta and step function power inputs is shown to have the same shape as the autocorrelation function for uncorrelated and correlated temperature fluctuations, respectively. The spectrum obtained from the cosine transform of the measured step function response is in excellent agreement with the measured 1/f voltage noise spectrum. Spatially correlated equilibrium temperature fluctuations are not the dominant source of 1/f noise in semiconductors and metal films. However, the agreement between the low-frequency spectrum of fluctuations in the mean-square Johnson noise voltage and the resistance fluctuation spectrum measured in the presence of a current demonstrates that in these systems the 1/f noise is also due to equilibrium resistance fluctuations. Loudness fluctuations in music and speech and pitch fluctuations in music also show the 1/f behavior. 1/f noise sources, consequently, are demonstrated to be the natural choice for stochastic composition. 26 figures, 1 table. (auth)« less

  19. Eating For Two: How Metabolism Establishes Interspecies Interactions in the Gut

    PubMed Central

    Fischbach, Michael A.; Sonnenburg, Justin L.

    2011-01-01

    In bacterial communities, ‘tight economic times’ are the norm. Of the many challenges bacteria face in making a living, perhaps none are more important than generating energy, maintaining redox balance, and acquiring carbon and nitrogen to synthesize primary metabolites. The ability of bacteria to meet these challenges depends heavily on the rest of their community. Indeed, the most fundamental way in which bacteria communicate is by importing the substrates for metabolism and exporting metabolic end products. As an illustration of this principle, we will travel down a carbohydrate catabolic pathway common to many species of Bacteroides, highlighting the interspecies interactions established (often inevitably) at its key steps. We also discuss the metabolic considerations in maintaining the stability of host-associated microbial communities. PMID:22018234

  20. Unidirectional hybrid male sterility from crosses between species A and species B of the taxon Anopheles (Cellia) culicifacies Giles.

    PubMed

    Miles, S J

    1981-02-01

    Crosses between species A females and species B males of the taxon Anopheles culicifacies give F1 males with undeveloped testes, reduced vasa deferentia, and apparently normal accessory glands. F1 males from the reciprocal cross, and F1 hybrid females from both reciprocal crosses are fertile, though their fertility is less than that of either parental species

  1. Fibroblast cell line establishment, cryopreservation and interspecies embryos reconstruction in red panda ( Ailurus fulgens).

    PubMed

    Tao, Yong; Liu, Jianming; Zhang, Yunhai; Zhang, Meiling; Fang, Junshun; Han, Wei; Zhang, Zhizhong; Liu, Ya; Ding, Jianping; Zhang, Xiaorong

    2009-05-01

    In evolution, the red panda (Ailurus fulgens) plays a pivotal role in the higher level phylogeny of arctoides carnivore mammals. The red panda inhabits certain Asian countries only and its numbers are decreasing. Therefore, the development of feasible ways to preserve this species is necessary. Genetic resource cryopreservation and somatic cell nuclear transfer (SCNT) have been used extensively to rescue this endangered species. The present study describes the establishment, for the first time, of a red panda ear fibroblast cell line, which was then cryopreserved, thawed and cultured. Through micromanipulation, interspecies embryos were reconstructed using the cryopreserved-thawed fibroblasts of the red panda as the donor and rabbit oocytes as recipients. A total of 194 enucleated rabbit oocytes were reconstructed with red panda ear fibroblasts; enucleated oocytes were activated without fusion as the control. The results show that the fibroblast cell line was established successfully by tissue culture and then cryopreserved in liquid nitrogen. Supplementation with 20% fetal bovine serum and 8% dimethyl sulphoxide in basic medium facilitated the cryopreservation. The interspecies embryos were successfully reconstructed. The cleavage, morulae and blastocyst rates after in vitro culture were 71, 47 and 23% (31/194), respectively. This study indicated that a somatic cell line could be established and cryopreserved from red panda and that rabbit cytoplast supports mitotic cleavage of the red panda karyoplasts and is capable of reprogramming the nucleus to achieve blastocysts.

  2. Reproductive isolation and hybridization in sympatric populations of three Dactylorhiza species (Orchidaceae) with different ploidy levels

    PubMed Central

    De hert, Koen; Jacquemyn, Hans; Van Glabeke, Sabine; Roldán-Ruiz, Isabel; Vandepitte, Katrien; Leus, Leen; Honnay, Olivier

    2012-01-01

    Background and Aims The potential for gene exchange between species with different ploidy levels has long been recognized, but only a few studies have tested this hypothesis in situ and most of them focused on not more than two co-occurring species. In this study, we examined hybridization patterns in two sites containing three species of the genus Dactylorhiza (diploid D. incarnata and D. fuchsii and their allotetraploid derivative D. praetermissa). Methods To compare the strength of reproductive barriers between diploid species, and between diploid and tetraploid species, crossing experiments were combined with morphometric and molecular analyses using amplified fragment length polymorphism markers, whereas flow cytometric analyses were used to verify the hybrid origin of putative hybrids. Key Results In both sites, extensive hybridization was observed, indicating that gene flow between species is possible within the investigated populations. Bayesian assignment analyses indicated that the majority of hybrids were F1 hybrids, but in some cases triple hybrids (hybrids with three species as parents) were observed, suggesting secondary gene flow. Crossing experiments showed that only crosses between pure species yielded a high percentage of viable seeds. When hybrids were involved as either pollen-receptor or pollen-donor, almost no viable seeds were formed, indicating strong post-zygotic reproductive isolation and high sterility. Conclusions Strong post-mating reproductive barriers prevent local breakdown of species boundaries in Dactylorhiza despite frequent hybridization between parental species. However, the presence of triple hybrids indicates that in some cases hybridization may extend the F1 generation. PMID:22186278

  3. Development of f2/f1 ratio functions in humans

    NASA Astrophysics Data System (ADS)

    Vento, Barbara A.; Durrant, John D.; Sabo, Diane L.; Boston, J. Robert

    2004-05-01

    Otoacoustic emissions (OAEs) presumably represent active processes within the cochlea fundamental to frequency-selectivity in peripheral auditory function. Maturation of the cochlear amplifier, vis-a-vis frequency encoding or selectivity, has yet to be fully characterized in humans. The purpose of this study was to further investigate the maturation of features of the f2/f1 frequency ratio (Distortion Product OAE amplitude X f2/f1 ratio) presumed to reflect cochlear frequency selectivity. A cross-sectional, multivariate study was completed comparing three age groups: pre-term infants, term infants and young adult subjects. Frequency ratio functions were analyzed at three f2 frequencies-2000, 4000 and 6000 Hz. An analysis included an estimation of the optimal ratio (OR) and a bandwidth-like measure (Q3). Analysis revealed significant interactions of age x frequency x gender for optimal ratio and a significant interaction of age x frequency for Q3. Consistent and statistically significant differences for both OR and Q3 were found in female subjects and when f2=2 or 6 kHz. This supports research by others [Abdala, J. Acoust. Soc. Am. 114, 3239-3250 (2003)] suggesting that the development of cochlear active mechanisms may still be somewhat in flux at least through term birth Furthermore, OAEs appear to demonstrate gender differences in the course of such maturational changes.

  4. Genetic Architecture of Male Sterility and Segregation Distortion in Drosophila pseudoobscura Bogota–USA Hybrids

    PubMed Central

    Phadnis, Nitin

    2011-01-01

    Understanding the genetic basis of reproductive isolation between recently diverged species is a central problem in evolutionary genetics. Here, I present analyses of the genetic architecture underlying hybrid male sterility and segregation distortion between the Bogota and USA subspecies of Drosophila pseudoobscura. Previously, a single gene, Overdrive (Ovd), was shown to be necessary but not sufficient for both male sterility and segregation distortion in F1 hybrids between these subspecies, requiring several interacting partner loci for full manifestation of hybrid phenomena. I map these partner loci separately on the Bogota X chromosome and USA autosomes using a combination of different mapping strategies. I find that hybrid sterility involves a single hybrid incompatibility of at least seven interacting partner genes that includes three large-effect loci. Segregation distortion involves three loci on the Bogota X chromosome and one locus on the autosomes. The genetic bases of hybrid sterility and segregation distortion are at least partially—but not completely—overlapping. My results lay the foundation for fine-mapping experiments to identify the complete set of genes that interact with Overdrive. While individual genes that cause hybrid sterility or inviability have been identified in a few cases, my analysis provides a comprehensive look at the genetic architecture of all components of a hybrid incompatibility underlying F1 hybrid sterility. Such an analysis would likely be unfeasible for most species pairs due to their divergence time and emphasizes the importance of young species pairs such as the D. pseudoobscura subspecies studied here. PMID:21900263

  5. Genetic architecture of male sterility and segregation distortion in Drosophila pseudoobscura Bogota-USA hybrids.

    PubMed

    Phadnis, Nitin

    2011-11-01

    Understanding the genetic basis of reproductive isolation between recently diverged species is a central problem in evolutionary genetics. Here, I present analyses of the genetic architecture underlying hybrid male sterility and segregation distortion between the Bogota and USA subspecies of Drosophila pseudoobscura. Previously, a single gene, Overdrive (Ovd), was shown to be necessary but not sufficient for both male sterility and segregation distortion in F(1) hybrids between these subspecies, requiring several interacting partner loci for full manifestation of hybrid phenomena. I map these partner loci separately on the Bogota X chromosome and USA autosomes using a combination of different mapping strategies. I find that hybrid sterility involves a single hybrid incompatibility of at least seven interacting partner genes that includes three large-effect loci. Segregation distortion involves three loci on the Bogota X chromosome and one locus on the autosomes. The genetic bases of hybrid sterility and segregation distortion are at least partially--but not completely--overlapping. My results lay the foundation for fine-mapping experiments to identify the complete set of genes that interact with Overdrive. While individual genes that cause hybrid sterility or inviability have been identified in a few cases, my analysis provides a comprehensive look at the genetic architecture of all components of a hybrid incompatibility underlying F(1) hybrid sterility. Such an analysis would likely be unfeasible for most species pairs due to their divergence time and emphasizes the importance of young species pairs such as the D. pseudoobscura subspecies studied here.

  6. Transposable Element Misregulation Is Linked to the Divergence between Parental piRNA Pathways in Drosophila Hybrids

    PubMed Central

    Romero-Soriano, Valèria; Modolo, Laurent; Lopez-Maestre, Hélène; Mugat, Bruno; Pessia, Eugénie; Chambeyron, Séverine; Vieira, Cristina

    2017-01-01

    Abstract Interspecific hybridization is a genomic stress condition that leads to the activation of transposable elements (TEs) in both animals and plants. In hybrids between Drosophila buzzatii and Drosophila koepferae, mobilization of at least 28 TEs has been described. However, the molecular mechanisms underlying this TE release remain poorly understood. To give insight on the causes of this TE activation, we performed a TE transcriptomic analysis in ovaries (notorious for playing a major role in TE silencing) of parental species and their F1 and backcrossed (BC) hybrids. We find that 15.2% and 10.6% of the expressed TEs are deregulated in F1 and BC1 ovaries, respectively, with a bias toward overexpression in both cases. Although differences between parental piRNA (Piwi-interacting RNA) populations explain only partially these results, we demonstrate that piRNA pathway proteins have divergent sequences and are differentially expressed between parental species. Thus, a functional divergence of the piRNA pathway between parental species, together with some differences between their piRNA pools, might be at the origin of hybrid instabilities and ultimately cause TE misregulation in ovaries. These analyses were complemented with the study of F1 testes, where TEs tend to be less expressed than in D. buzzatii. This can be explained by an increase in piRNA production, which probably acts as a defence mechanism against TE instability in the male germline. Hence, we describe a differential impact of interspecific hybridization in testes and ovaries, which reveals that TE expression and regulation are sex-biased. PMID:28854624

  7. Inter-species protein trafficking endows dodder (Cuscuta pentagona) with a host-specific herbicide-tolerant trait.

    PubMed

    Jiang, Linjian; Qu, Feng; Li, Zhaohu; Doohan, Douglas

    2013-06-01

    · Besides photosynthates, dodder (Cuscuta spp.) acquires phloem-mobile proteins from host; however, whether this could mediate inter-species phenotype transfer was not demonstrated. Specifically, we test whether phosphinothricin acetyl transferase (PAT) that confers host plant glufosinate herbicide tolerance traffics and functions inter-specifically. · Dodder tendrils excised from hosts can grow in vitro for weeks or resume in vivo by parasitizing new hosts. The level of PAT in in vivo and in vitro dodder tendrils was quantified by enzyme-linked immunosorbent assay. The glufosinate sensitivity was examined by dipping the distal end of in vivo and in vitro tendrils, growing on or excised from LibertyLink (LL; PAT-transgenic and glufosinate tolerant) and conventional (CN; glufosinate sensitive) soybean hosts, into glufosinate solutions for 5 s. After in vitro tendrils excised from LL hosts reparasitized new CN and LL hosts, the PAT level and the glufosinate sensitivity were also examined. · When growing on LL host, dodder tolerated glufosinate and contained PAT at a level of 0.3% of that encountered in LL soybean leaf. After PAT was largely degraded in dodders, they became glufosinate sensitive. PAT mRNA was not detected by reverse transcription PCR in dodders. · In conclusion, the results indicated that PAT inter-species trafficking confers dodder glufosinate tolerance. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  8. CYTOLOGICAL CHARACTERIZATION OF PREMEIOTIC VERSUS POSTMEIOTIC DEFECTS PRODUCING HYBRID MALE STERILITY AMONG SIBLING SPECIES OF THE DROSOPHILA MELANOGASTER COMPLEX.

    PubMed

    Kulathinal, Rob; Singh, Rama S

    1998-08-01

    In accordance with Haldane's rule, hybridizations between species of the Drosophila simulans clade produce fertile females but sterile males. In this study, a comprehensive characterization was undertaken on the six types of F 1 males that were the result of the crosses between D. simulans, D. sechellia, and D. mauritiana. With the use of light and electron microscopy, it was shown that while each particular hybrid genotype exhibited a specific sterility phenotype, these phenotypes fell into two distinct classes. The two hybrid genotypes that possessed D. mauritiana X-chromosomes contained spermatogenic defects that caused arrests in premeiotic spermatogenic stages. The other four F 1 hybrids possessed postmeiotic spermatogenic defects. Nonsynchronous cell divisions, underdeveloped mitochondrial derivative-axonemal associations, and microtubule abnormalities were common to all of these hybrids. Each particular postmeiotically defective hybrid genotype demonstrated characteristically distinct profiles in sperm bundle number in addition to characteristic spermiogenic arrests in the furthest developed spermatids. These results in species hybrids contrast with the absence of significant differences in spermatogenic characters between species of this clade. In addition, by utilizing an attached-X cross, we investigated the influence of maternal effects and cytoplasmic factors on the sterility of D. simulans F 1 hybrids and found none. However, we discovered a strain of D. simulans (2119) that caused a large shift in sterility from postmeiotic to premeiotic when crossed to D. sechellia. This suggests that D. simulans is polymorphic for genes involving premeiotic and postmeiotic sterility and that the two types of sterilities between species may have a simple genetic basis. © 1998 The Society for the Study of Evolution.

  9. Hybrid Monoterpenoid Indole Alkaloids Obtained as Artifacts from Rauvolfia tetraphylla.

    PubMed

    Gao, Yuan; Zhou, Dong-Sheng; Hai, Ping; Li, Yan; Wang, Fei

    2015-10-01

    Five new hybrid monoterpenoid indole alkaloids bearing an unusual 2,2-dimethyl-4-oxopiperidin-6-yl moiety, namely rauvotetraphyllines F-H (1, 3, 4), 17-epi-rauvotetraphylline F (2) and 21-epi-rauvotetraphylline H (5), were isolated from the aerial parts of Rauvolfia tetraphylla. Their structures were established by extensive spectroscopic analysis. The new alkaloids were evaluated for their cytotoxicity in vitro against five human cancer cell lines.

  10. Efficient engineering of marker-free synthetic allotetraploids of Saccharomyces.

    PubMed

    Alexander, William G; Peris, David; Pfannenstiel, Brandon T; Opulente, Dana A; Kuang, Meihua; Hittinger, Chris Todd

    2016-04-01

    Saccharomyces interspecies hybrids are critical biocatalysts in the fermented beverage industry, including in the production of lager beers, Belgian ales, ciders, and cold-fermented wines. Current methods for making synthetic interspecies hybrids are cumbersome and/or require genome modifications. We have developed a simple, robust, and efficient method for generating allotetraploid strains of prototrophic Saccharomyces without sporulation or nuclear genome manipulation. S. cerevisiae×S. eubayanus, S. cerevisiae×S. kudriavzevii, and S. cerevisiae×S. uvarum designer hybrid strains were created as synthetic lager, Belgian, and cider strains, respectively. The ploidy and hybrid nature of the strains were confirmed using flow cytometry and PCR-RFLP analysis, respectively. This method provides an efficient means for producing novel synthetic hybrids for beverage and biofuel production, as well as for constructing tetraploids to be used for basic research in evolutionary genetics and genome stability. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. 26 CFR 1.514(f)-1 - Definition of business lease.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Definition of business lease. 1.514(f)-1 Section 1.514(f)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Taxation of Business Income of Certain Exempt Organizations...

  12. Inter-species chimeras of leukaemia inhibitory factor define a major human receptor-binding determinant.

    PubMed Central

    Owczarek, C M; Layton, M J; Metcalf, D; Lock, P; Willson, T A; Gough, N M; Nicola, N A

    1993-01-01

    Human leukaemia inhibitory factor (hLIF) binds to both human and mouse LIF receptors (LIF-R), while mouse LIF (mLIF) binds only to mouse LIF-R. Moreover, hLIF binds with higher affinity to the mLIF-R than does mLIF. In order to define the regions of the hLIF molecule responsible for species-specific interaction with the hLIF-R and for the unusual high-affinity binding to the mLIF-R, a series of 15 mouse/human LIF hybrids has been generated. Perhaps surprisingly, both of these properties mapped to the same region of the hLIF molecule. The predominant contribution was from residues in the loop linking the third and fourth helices, with lesser contributions from residues in the third helix and the loop connecting the second and third helices in the predicted three-dimensional structure. Since all chimeras retained full biological activity and receptor-binding activity on mouse cells, and there was little variation in the specific biological activity of the purified proteins, it can be concluded that the overall secondary and tertiary structures of each chimera were intact. This observation also implied that the primary binding sites on mLIF and hLIF for the mLIF-R were unaltered by inter-species domain swapping. Consequently, the site on the hLIF molecule that confers species-specific binding to the hLIF-R and higher affinity binding to the mLIF-R, must constitute an additional interaction site to that used by both mLIF and hLIF to bind to the mLIF-R. These studies define a maximum of 15 amino acid differences between hLIF and mLIF that are responsible for the different properties of these proteins. Images PMID:8253075

  13. The DBP Phenotype Gc-1f/Gc-1f Is Associated with Reduced Risk of Cancer. The Tromsø Study

    PubMed Central

    Jorde, Rolf; Schirmer, Henrik; Wilsgaard, Tom; Bøgeberg Mathiesen, Ellisiv; Njølstad, Inger; Løchen, Maja-Lisa; Joakimsen, Ragnar Martin; Grimnes, Guri

    2015-01-01

    Background and Objective In addition to its role as a transport protein, the vitamin D binding protein (DBP) may also affect lipid metabolism, inflammation and carcinogenesis. There are three common variants of the DBP, Gc1s (1s), Gc1f (1f), Gc2 (2) that result in six common phenotypes (1s/1s, 1s/1f, 1s/2, 1f/1f, 1f/2, and 2/2). These phenotypes can be identified by genotyping for the two single nucleotide polymorphisms rs7041 and rs4588 in the GC gene. The DBP variants have different binding coefficients for the vitamin D metabolites, and accordingly there may be important relations between DBP phenotypes and health. Methods DNA was prepared from subjects who participated in the fourth survey of the Tromsø Study in 1994-1995 and who were registered with the endpoints myocardial infarction (MI), type 2 diabetes (T2DM), cancer or death as well as a randomly selected control group. The endpoint registers were complete up to 2010- 2013. Genotyping was performed for rs7041 and rs4588 and serum 25-hydroxyvitamin D (25(OH)D) was measured. Results Genotyping for rs7041 and rs4588 was performed successfully in 11 704 subjects. Among these, 1660 were registered with incident MI, 958 with T2DM, 2410 with cancer and 4318 had died. Subjects with the DBP phenotype 1f/1f had 23 – 26 % reduced risk of incident cancer compared to the 1s/1s and 2/2 phenotypes (P < 0.02, Cox regression with gender as covariate). Differences in serum 25(OH)D levels could not explain the apparent cancer protective effect of the DBP variant 1f. In addition to cancer and 25(OH)D, there were significant associations between DBP phenotype and body height, hip circumference and serum calcium. Conclusion There are important biological differences between the common DBP phenotypes. If the relation between the DBP variant 1f and cancer is confirmed in other studies, determination of DBP phenotype may have clinical importance. PMID:25993554

  14. Polyploidy Enhances F1 Pollen Sterility Loci Interactions That Increase Meiosis Abnormalities and Pollen Sterility in Autotetraploid Rice.

    PubMed

    Wu, Jinwen; Shahid, Muhammad Qasim; Chen, Lin; Chen, Zhixiong; Wang, Lan; Liu, Xiangdong; Lu, Yonggen

    2015-12-01

    Intersubspecific autotetraploid rice (Oryza sativa ssp. indica × japonica) hybrids have greater biological and yield potentials than diploid rice. However, the low fertility of intersubspecific autotetraploid hybrids, which is largely caused by high pollen abortion rates, limits their commercial utility. To decipher the cytological and molecular mechanisms underlying allelic interactions in autotetraploid rice, we developed an autotetraploid rice hybrid that was heterozygous (S(i)S(j)) at F1 pollen sterility loci (Sa, Sb, and Sc) using near-isogenic lines. Cytological studies showed that the autotetraploid had higher percentages (>30%) of abnormal chromosome behavior and aberrant meiocytes (>50%) during meiosis than did the diploid rice hybrid control. Analysis of gene expression profiles revealed 1,888 genes that were differentially expressed between the autotetraploid and diploid hybrid lines at the meiotic stage, among which 889 and 999 were up- and down-regulated, respectively. Of the 999 down-regulated genes, 940 were associated with the combined effect of polyploidy and pollen sterility loci interactions (IPE). Gene Ontology enrichment analysis identified a prominent functional gene class consisting of seven genes related to photosystem I (Gene Ontology 0009522). Moreover, 55 meiosis-related or meiosis stage-specific genes were associated with IPE in autotetraploid rice, including Os02g0497500, which encodes a DNA repair-recombination protein, and Os02g0490000, which encodes a component of the ubiquitin-proteasome pathway. These results suggest that polyploidy enhances epistatic interactions between alleles of pollen sterility loci, thereby altering the expression profiles of important meiosis-related or meiosis stage-specific genes and resulting in high pollen sterility. © 2015 American Society of Plant Biologists. All Rights Reserved.

  15. Reconstruction of the Strawberry, Fragaria × ananassa, Using Native Genotypes of F. virginiana and F. chiloensis

    USDA-ARS?s Scientific Manuscript database

    The germplasm base of strawberries is restricted. The major cultivated strawberry species, Fragaria ananassa, originated about 250 years ago when South American F. chiloensis subsp. chiloensis forma chiloensis and North American F. virginiana subsp. virginiana accidentally hybridized in European ga...

  16. Coherent and conventional gravidynamic quantum 1/f noise

    NASA Astrophysics Data System (ADS)

    Handel, Peter H.; George, Thomas F.

    2008-04-01

    Quantum 1/f noise is a fundamental fluctuation of currents, physical cross sections or process rates, caused by infrared coupling of the current carriers to very low frequency (soft) quanta, also known as infraquanta. The latter are soft gravitons in the gravidynamic case with the coupling constant g= pGM2/Nch considered here -- soft photons in the electrodynamic case and soft transversal piezo-phonons in the lattice-dynamical case. Here p=3.14 and F=psi. Quantum 1/f noise is a new aspect of quantum mechanics expressed mainly through the coherent quantum 1/f effect 2g/pf derived here for large systems, and mainly through the conventional quantum 1/f effect for small systems or individual particles. Both effects are present in general, and their effects are superposed in a first approximation with the help of a coherence (weight) parameter s" that will be derived elsewhere for the gravitational case. The spectral density of fractional fluctuations S(dj/j,f) for j=e(hk/2pm)|F|2 is S(F2,f)/<|F|2> = S(j,f)/2 = [4ps"/(1+s")]GM2/pfNch = 4.4 10E9 M2/(pfNgram2). Here s" = 2N'GM/c2=N'rs, where N' is the number of particles of mass M per unit length of the current, rs their Schwarzschild radius, and s" is our coherence (weight) parameter giving the ratio of coherent to conventional quantum 1/f contributions.

  17. Biochemical identification of mallard-black duck hybrids through a breeding program and in nature

    USGS Publications Warehouse

    Morgan, R.P.; Meritt, D.W.; Block, S.B.; Cole, M.

    1978-01-01

    From 1974 to 1976, a breeding program was used to produce black duck-mallard hybrids for the evaluation of inheritance patterns of serum proteins and esterases. In addition to the initial crosses, a series of matings in 1975 and 1976 were designed to evaluate inheritance patterns in hybrid matings with either black duck or mallards. At the F1 level, hybrids were easily distinguished. However, mallard or black duck crosses with hybrids were detectable as hybrids in only 11.5 - 22.6% of the progeny using serum proteins, and 22.6 - 38.8% using serum esterases. Concurrent with the breeding program, a field survey indicated hybrid frequencies ranging from 4% to 28%.

  18. Enhanced UV photoresponse of KrF-laser-synthesized single-wall carbon nanotubes/n-silicon hybrid photovoltaic devices.

    PubMed

    Le Borgne, V; Gautier, L A; Castrucci, P; Del Gobbo, S; De Crescenzi, M; El Khakani, M A

    2012-06-01

    We report on the KrF-laser ablation synthesis, purification and photocurrent generation properties of single-wall carbon nanotubes (SWCNTs). The thermally purified SWCNTs are integrated into hybrid photovoltaic (PV) devices by spin-coating them onto n-Si substrates. These novel SWCNTs/n-Si hybrid devices are shown to generate significant photocurrent (PC) over the entire 250-1050 nm light spectrum with external quantum efficiencies (EQE) reaching up to ~23%. Our SWCNTs/n-Si hybrid devices are not only photoactive in the traditional spectral range of Si solar cells, but generate also significant PC in the UV domain (below 400 nm). This wider spectral response is believed to be the result of PC generation from both the SWCNTs themselves and the tremendous number of local p-n junctions created at the nanotubes/Si interface. To assess the prevalence of these two contributions, the EQE spectra and J-V characteristics of these hybrid devices were investigated in both planar and top-down configurations, as a function of SWCNTs' film thickness. A sizable increase in EQE in the near UV with respect to the silicon is observed in both configurations, with a more pronounced UV photoresponse in the planar mode, confirming thereby the role of SWCNTs in the photogeneration process. The PC generation is found to reach its maximum for an optimal the SWCNT film thickness, which is shown to correspond to the best trade-off between lowest electrical resistance and highest optical transparency. Finally, by analyzing the J-V characteristics of our SWCNTs/n-Si devices with an equivalent circuit model, we were able to point out the contribution of the various electrical components involved in the photogeneration process. The SWCNTs-based devices demonstrated here open up the prospect for their use in highly effective photovoltaics and/or UV-light sensors.

  19. 26 CFR 1.514(f)-1 - Definition of business lease.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Definition of business lease. 1.514(f)-1 Section... TAX (CONTINUED) INCOME TAXES (CONTINUED) Taxation of Business Income of Certain Exempt Organizations § 1.514(f)-1 Definition of business lease. (a) In general. The term business lease means any lease...

  20. 26 CFR 1.514(f)-1 - Definition of business lease.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 7 2013-04-01 2013-04-01 false Definition of business lease. 1.514(f)-1 Section... TAX (CONTINUED) INCOME TAXES (CONTINUED) Taxation of Business Income of Certain Exempt Organizations § 1.514(f)-1 Definition of business lease. (a) In general. The term business lease means any lease...

  1. 26 CFR 1.514(f)-1 - Definition of business lease.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 7 2012-04-01 2012-04-01 false Definition of business lease. 1.514(f)-1 Section... TAX (CONTINUED) INCOME TAXES (CONTINUED) Taxation of Business Income of Certain Exempt Organizations § 1.514(f)-1 Definition of business lease. (a) In general. The term business lease means any lease...

  2. Use of repetitive DNA sequences to distinguish Mus musculus and Mus caroli cells by in situ hybridization.

    PubMed

    Siracusa, L D; Chapman, V M; Bennett, K L; Hastie, N D; Pietras, D F; Rossant, J

    1983-02-01

    Mammalian chimaeras have proved useful for investigating early steps in embryonic development. However, a complete clonal analysis of cell lineages has been limited by the lack of a marker which is ubiquitous and can distinguish parental cell types in situ. We have developed a cell marker system which fulfils these criteria. Chimaeric mice were successfully produced from two mouse species which possess sufficient genetic differences to allow unequivocal identification of parental cell types. DNA-DNA in situ hybridization with cloned, species-specific sequences was performed to distinguish the parental cell types. We have identified a cloned, Mus musculus satellite DNA sequence which shows hybridization differences between Mus musculus and Mus caroli DNA. This clone was used a a probe in in situ hybridizations to bone marrow chromosomes from Mus musculus, Mus caroli, and an interspecific F1 hybrid. The clone could qualitatively distinguish Mus musculus from Mus caroli chromosomes after in situ hybridization, even when they were derived from the same F1 hybrid cell. Quantitation of this hybridization to interphase nuclei from bone marrow spreads indicates that the probe can successfully distinguish Mus musculus from Mus caroli cells and can determine the percentage contribution of Mus musculus in mixtures of bone marrow cells of these species and in chimaeric bone marrow cell preparations.

  3. A breeding strategy to harness flavor diversity of Saccharomyces interspecific hybrids and minimize hydrogen sulfide production.

    PubMed

    Bizaj, Etjen; Cordente, Antonio G; Bellon, Jennifer R; Raspor, Peter; Curtin, Chris D; Pretorius, Isak S

    2012-06-01

    Industrial food-grade yeast strains are selected for traits that enhance their application in quality production processes. Wine yeasts are required to survive in the harsh environment of fermenting grape must, while at the same time contributing to wine quality by producing desirable aromas and flavors. For this reason, there are hundreds of wine yeasts available, exhibiting characteristics that make them suitable for different fermentation conditions and winemaking practices. As wine styles evolve and technical winemaking requirements change, however, it becomes necessary to improve existing strains. This becomes a laborious and costly process when the targets for improvement involve flavor compound production. Here, we demonstrate a new approach harnessing preexisting industrial yeast strains that carry desirable flavor phenotypes - low hydrogen sulfide (H(2) S) production and high ester production. A low-H(2) S Saccharomyces cerevisiae strain previously generated by chemical mutagenesis was hybridized independently with two ester-producing natural interspecies hybrids of S. cerevisiae and Saccharomyces kudriavzevii. Deficiencies in sporulation frequency and spore viability were overcome through use of complementary selectable traits, allowing successful isolation of several novel hybrids exhibiting both desired traits in a single round of selection. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  4. Inheritance patterns of enzymes and serum proteins of mallard-black duck hybrids

    USGS Publications Warehouse

    Morgan, R.P.; Meritt, D.W.; Block, S.B.; Cole, M.

    1984-01-01

    From 1974 to 1976, a breeding program was used to produce hybrids of black ducks and mallards for the evaluation of inheritance patterns of serum proteins and serum, liver and muscle enzymes. In addition to the crosses designed to produce hybrids, a series of matings in 1975 and 1976 were designed to evaluate inheritance patterns of a hybrid with either a black duck or mallard. At the F1 level, hybrids were easily distinguished using serum proteins. However, once a hybrid was crossed back to either a mallard or black duck, only 12-23% of the progeny were distinguishable from black ducks or mallards using serum proteins and 23-39% using esterases. Muscle, serum and liver enzymes were similar between the two species.

  5. Inheritance patterns of enzymes and serum proteins of mallard-black duck hybrids

    USGS Publications Warehouse

    Morgan, R.P.; Meritt, D.W.; Block, S.B.; Cole, M.A.; Sulkin, S.T.; Lee, F.B.; Henny, C.J.

    1984-01-01

    From 1974 to 1976, a breeding program was used to produce hybrids of black ducks and mallards for the evaluation of inheritance patterns of serum proteins and serum, liver and muscle enzymes. In addition to the crosses designed to produce hybrids, a series of matings in 1975 and 1976 were designed to evaluate inheritance patterns of a hybrid with either a black duck or mallard. At the F1 level, hybrids were easily distinguished using serum proteins. However, once a hybrid was crossed back to either a mallard or black duck, only 12?23% of the progeny were distinguishable from black ducks or mallards using serum proteins and 23?39% using esterases. Muscle, serum and liver enzymes were similar between the two species.

  6. Fitness of Crop-Wild Hybrid Sunflower under Competitive Conditions: Implications for Crop-to-Wild Introgression

    PubMed Central

    Mercer, Kristin L.; Emry, D. Jason; Snow, Allison A.; Kost, Matthew A.; Pace, Brian A.; Alexander, Helen M.

    2014-01-01

    Understanding the likelihood and extent of introgression of novel alleles in hybrid zones requires comparison of lifetime fitness of parents and hybrid progeny. However, fitness differences among cross types can vary depending on biotic conditions, thereby influencing introgression patterns. Based on past work, we predicted that increased competition would enhance introgression between cultivated and wild sunflower (Helianthus annuus) by reducing fitness advantages of wild plants. To test this prediction, we established a factorial field experiment in Kansas, USA where we monitored the fitness of four cross types (Wild, F1, F2, and BCw hybrids) under different levels of interspecific and intraspecific competition. Intraspecific manipulations consisted both of density of competitors and of frequency of crop-wild hybrids. We recorded emergence of overwintered seeds, survival to reproduction, and numbers of seeds produced per reproductive plant. We also calculated two compound fitness measures: seeds produced per emerged seedling and seeds produced per planted seed. Cross type and intraspecific competition affected emergence and survival to reproduction, respectively. Further, cross type interacted with competitive treatments to influence all other fitness traits. More intense competition treatments, especially related to density of intraspecific competitors, repeatedly reduced the fitness advantage of wild plants when considering seeds produced per reproductive plant and per emerged seedling, and F2 plants often became indistinguishable from the wilds. Wild fitness remained superior when seedling emergence was also considered as part of fitness, but the fitness of F2 hybrids relative to wild plants more than quadrupled with the addition of interspecific competitors and high densities of intraspecific competitors. Meanwhile, contrary to prediction, lower hybrid frequency reduced wild fitness advantage. These results emphasize the importance of taking a full life cycle

  7. Fitness of crop-wild hybrid sunflower under competitive conditions: implications for crop-to-wild introgression.

    PubMed

    Mercer, Kristin L; Emry, D Jason; Snow, Allison A; Kost, Matthew A; Pace, Brian A; Alexander, Helen M

    2014-01-01

    Understanding the likelihood and extent of introgression of novel alleles in hybrid zones requires comparison of lifetime fitness of parents and hybrid progeny. However, fitness differences among cross types can vary depending on biotic conditions, thereby influencing introgression patterns. Based on past work, we predicted that increased competition would enhance introgression between cultivated and wild sunflower (Helianthus annuus) by reducing fitness advantages of wild plants. To test this prediction, we established a factorial field experiment in Kansas, USA where we monitored the fitness of four cross types (Wild, F1, F2, and BCw hybrids) under different levels of interspecific and intraspecific competition. Intraspecific manipulations consisted both of density of competitors and of frequency of crop-wild hybrids. We recorded emergence of overwintered seeds, survival to reproduction, and numbers of seeds produced per reproductive plant. We also calculated two compound fitness measures: seeds produced per emerged seedling and seeds produced per planted seed. Cross type and intraspecific competition affected emergence and survival to reproduction, respectively. Further, cross type interacted with competitive treatments to influence all other fitness traits. More intense competition treatments, especially related to density of intraspecific competitors, repeatedly reduced the fitness advantage of wild plants when considering seeds produced per reproductive plant and per emerged seedling, and F2 plants often became indistinguishable from the wilds. Wild fitness remained superior when seedling emergence was also considered as part of fitness, but the fitness of F2 hybrids relative to wild plants more than quadrupled with the addition of interspecific competitors and high densities of intraspecific competitors. Meanwhile, contrary to prediction, lower hybrid frequency reduced wild fitness advantage. These results emphasize the importance of taking a full life cycle

  8. Synthesis and characterization of carbon coated LiCo1/3Ni1/3Mn1/3O2 and bio-mass derived graphene like porous carbon electrodes for aqueous Li-ion hybrid supercapacitor

    NASA Astrophysics Data System (ADS)

    Ramkumar, B.; Yuvaraj, S.; Surendran, S.; Pandi, K.; Ramasamy, Hari Vignesh; Lee, Y. S.; Kalai Selvan, R.

    2018-01-01

    For the fabrication of aqueous Li-ion hybrid supercapacitor, carbon coated LiCo1/3Ni1/3Mn1/3O2 (or LiCo1/3Ni1/3Mn1/3O2@C composite) is synthesized by polymeric precursor method with subsequent thermal decomposition procedures for carbon coating. Graphene like porous carbon is obtained by chemical activation from the biomass of Agave Americana. The XRD analysis reveals that LiCo1/3Ni1/3Mn1/3O2 is having a hexagonal layered structure and activated carbon exists in both amorphous and graphitic nature. The TEM image infers that LiCo1/3Ni1/3Mn1/3O2 particles having the non-uniform shape with sub-micron size and the LiCo1/3Ni1/3Mn1/3O2 particles are embedded into amorphous carbon cloud in the composite. The activated carbon shows the specific surface area of 1219 m2 g-1. Finally, the fabricated aqueous LiCo1/3Ni1/3Mn1/3O2@C‖AC hybrid supercapacitor delivers the specific capacitance of 56 F g-1 with good capacity retention even after 5000 cycles.

  9. Interspecies differences in metabolism of arsenic by cultured primary hepatocytes

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

    Drobna, Zuzana; Walton, Felecia S.; Harmon, Anne W.

    2010-05-15

    Biomethylation is the major pathway for the metabolism of inorganic arsenic (iAs) in many mammalian species, including the human. However, significant interspecies differences have been reported in the rate of in vivo metabolism of iAs and in yields of iAs metabolites found in urine. Liver is considered the primary site for the methylation of iAs and arsenic (+3 oxidation state) methyltransferase (As3mt) is the key enzyme in this pathway. Thus, the As3mt-catalyzed methylation of iAs in the liver determines in part the rate and the pattern of iAs metabolism in various species. We examined kinetics and concentration-response patterns for iAsmore » methylation by cultured primary hepatocytes derived from human, rat, mice, dog, rabbit, and rhesus monkey. Hepatocytes were exposed to [{sup 73}As]arsenite (iAs{sup III}; 0.3, 0.9, 3.0, 9.0 or 30 nmol As/mg protein) for 24 h and radiolabeled metabolites were analyzed in cells and culture media. Hepatocytes from all six species methylated iAs{sup III} to methylarsenic (MAs) and dimethylarsenic (DMAs). Notably, dog, rat and monkey hepatocytes were considerably more efficient methylators of iAs{sup III} than mouse, rabbit or human hepatocytes. The low efficiency of mouse, rabbit and human hepatocytes to methylate iAs{sup III} was associated with inhibition of DMAs production by moderate concentrations of iAs{sup III} and with retention of iAs and MAs in cells. No significant correlations were found between the rate of iAs methylation and the thioredoxin reductase activity or glutathione concentration, two factors that modulate the activity of recombinant As3mt. No associations between the rates of iAs methylation and As3mt protein structures were found for the six species examined. Immunoblot analyses indicate that the superior arsenic methylation capacities of dog, rat and monkey hepatocytes examined in this study may be associated with a higher As3mt expression. However, factors other than As3mt expression may also

  10. Phylodynamics of HIV-1 subtype F1 in Angola, Brazil and Romania.

    PubMed

    Bello, Gonzalo; Afonso, Joana Morais; Morgado, Mariza G

    2012-07-01

    The HIV-1 subtype F1 is exceptionally prevalent in Angola, Brazil and Romania. The epidemiological context in which the spread of HIV occurred was highly variable from one country to another, mainly due to the existence of a long-term civil war in Angola and the contamination of a large number of children in Romania. Here we apply phylogenetic and Bayesian coalescent-based methods to reconstruct the phylodynamic patterns of HIV-1 subtype F1 in such different epidemiological settings. The phylogenetic analyses of HIV-1 subtype F1 pol sequences sampled worldwide confirmed that most sequences from Angola, Brazil and Romania segregated in country-specific monophyletic groups, while most subtype F1 sequences from Romanian children branched as a monophyletic sub-cluster (Romania-CH) nested within sequences from adults. The inferred time of the most recent common ancestor of the different subtype F1 clades were as follow: Angola=1983 (1978-1989), Brazil=1977 (1972-1981), Romania adults=1980 (1973-1987), and Romania-CH=1985 (1978-1989). All subtype F1 clades showed a demographic history best explained by a model of logistic population growth. Although the expansion phase of subtype F1 epidemic in Angola (mid 1980s to early 2000s) overlaps with the civil war period (1975-2002), the mean estimated growth rate of the Angolan F1 clade (0.49 year(-1)) was not exceptionally high, but quite similar to that estimated for the Brazilian (0.69 year(-1)) and Romanian adult (0.36 year(-1)) subtype F1 clades. The Romania-CH subtype F1 lineage, by contrast, displayed a short and explosive dissemination phase, with a median growth rate (2.47 year(-1)) much higher than that estimated for adult populations. This result supports the idea that the AIDS epidemic that affected the Romanian children was mainly caused by the spread of the HIV through highly efficient parenteral transmission networks, unlike adult populations where HIV is predominantly transmitted through sexual route. Copyright

  11. Small RNAs as important regulators for the hybrid vigour of super-hybrid rice.

    PubMed

    Zhang, Lei; Peng, Yonggang; Wei, Xiaoli; Dai, Yan; Yuan, Dawei; Lu, Yufei; Pan, Yangyang; Zhu, Zhen

    2014-11-01

    Heterosis is an important biological phenomenon; however, the role of small RNA (sRNA) in heterosis of hybrid rice remains poorly described. Here, we performed sRNA profiling of F1 super-hybrid rice LYP9 and its parents using high-throughput sequencing technology, and identified 355 distinct mature microRNAs and trans-acting small interfering RNAs, 69 of which were differentially expressed sRNAs (DES) between the hybrid and the mid-parental value. Among these, 34 DES were predicted to target 176 transcripts, of which 112 encoded 94 transcription factors. Further analysis showed that 67.6% of DES expression levels were negatively correlated with their target mRNAs either in flag leaves or panicles. The target genes of DES were significantly enriched in some important biological processes, including the auxin signalling pathway, in which existed a regulatory network mediated by DES and their targets, closely associated with plant growth and development. Overall, 20.8% of DES and their target genes were significantly enriched in quantitative trait loci of small intervals related to important rice agronomic traits including growth vigour, grain yield, and plant architecture, suggesting that the interaction between sRNAs and their targets contributes to the heterotic phenotypes of hybrid rice. Our findings revealed that sRNAs might play important roles in hybrid vigour of super-hybrid rice by regulating their target genes, especially in controlling the auxin signalling pathway. The above finding provides a novel insight into the molecular mechanism of heterosis. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  12. 40 CFR Figure F-1 to Subpart F of... - Designation Testing Checklist

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... tests must be performed:§ 53.62 - Full Wind Tunnel § 53.63 - Inlet Aspiration § 53.64 - Static... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Designation Testing Checklist F Figure F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

  13. 40 CFR Figure F-1 to Subpart F of... - Designation Testing Checklist

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... tests must be performed:§ 53.62 - Full Wind Tunnel § 53.63 - Inlet Aspiration § 53.64 - Static... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Designation Testing Checklist F Figure F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

  14. 40 CFR Figure F-1 to Subpart F of... - Designation Testing Checklist

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... tests must be performed:§ 53.62 - Full Wind Tunnel § 53.63 - Inlet Aspiration § 53.64 - Static... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Designation Testing Checklist F Figure F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

  15. 40 CFR Figure F-1 to Subpart F of... - Designation Testing Checklist

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... tests must be performed:§ 53.62 - Full Wind Tunnel § 53.63 - Inlet Aspiration § 53.64 - Static... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Designation Testing Checklist F Figure F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

  16. 40 CFR Figure F-1 to Subpart F of... - Designation Testing Checklist

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... tests must be performed:§ 53.62 - Full Wind Tunnel § 53.63 - Inlet Aspiration § 53.64 - Static... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Designation Testing Checklist F Figure F-1 to Subpart F of Part 53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

  17. Free-standing 3D polyaniline-CNT/Ni-fiber hybrid electrodes for high-performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Fang, Yuzhu; Liu, Hong; Wu, Xiaoming; Lu, Yong

    2012-04-01

    Free-standing 3D macroscopic polyaniline (PANi)-carbon nanotube (CNT)-nickel fiber hybrids have been developed, and they deliver high specific capacitance (725 F g-1 at 0.5 A g-1) and high energy density at high rates (~22 W h kg-1 at 2000 W kg-1, based on total electrode mass) with good cyclability.Free-standing 3D macroscopic polyaniline (PANi)-carbon nanotube (CNT)-nickel fiber hybrids have been developed, and they deliver high specific capacitance (725 F g-1 at 0.5 A g-1) and high energy density at high rates (~22 W h kg-1 at 2000 W kg-1, based on total electrode mass) with good cyclability. Electronic supplementary information (ESI) available: Experimental details on preparation, characterization, and electrochemical testing; Fig. S1-S8, Schemes S1 and S2. See DOI: 10.1039/c2nr30252g

  18. Induction of a glucocorticoid-sensitive F1-anti-parental mechanism that affects engraftment during graft-versus-host disease.

    PubMed

    You-Ten, K E; Seemayer, T A; Wisse, B; Bertley, F M; Lapp, W S

    1995-07-01

    Studies have shown that graft-vs-host disease (GVHD) in animal models induces persistent elevated levels of circulating adrenal glucocorticoids. In this report, we investigated the effects of endogenous glucocorticoids on the outcome of GVHD by adrenalectomizing (ADX) unirradiated (C57BL/6 x A)F1 (B6AF1) mice before GVHD induction. GVHD was induced by injection of 20 x 10(6) A strain parental lymphoid cells into B6AF1 mice. Our results demonstrated that non-ADX recipient mice experienced features characteristic of GVHD on day 13, which became progressively more severe by days 18 to 21. The GVHD features included severe immunosuppression, reversal in the host splenic CD4+/CD8+ ratio, histopathologic lesions in different tissues, and high parental cell chimerism in the spleens and lymph nodes. In contrast, ADX F1 recipient mice experienced GVHD features on day 13 similar to their non-ADX counterparts; however, ADX animals recovered rapidly from GVHD by days 18 to 21. Flow cytometry showed that, although a relatively high frequency of parental cells was detected in the spleens and lymph nodes of ADX mice on day 13, nearly all of the parental cells in the peripheral lymphoid organs disappeared on days 18 to 21, the time of recovery from GVHD. The marked reduction of parental cells and recovery from GVHD were prevented by treating ADX F1 mice with either exogenous glucocorticoid, anti-asialoGM1, or anti-CD8, but not anti-NK1.1 Ab. These results suggest that a dramatic recovery from GVHD was induced by a cell-mediated, steroid-sensitive F1-anti-parental mechanism. The F1-anti-parental phenomenon described herein is different from classical hybrid resistance.

  19. An Interspecies Signaling System Mediated by Fusaric Acid Has Parallel Effects on Antifungal Metabolite Production by Pseudomonas protegens Strain Pf-5 and Antibiosis of Fusarium spp.

    PubMed Central

    Quecine, Maria Carolina; Kidarsa, Teresa A.; Goebel, Neal C.; Shaffer, Brenda T.; Henkels, Marcella D.; Zabriskie, T. Mark

    2015-01-01

    Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogens Fusarium verticillioides and Fusarium oxysporum f. sp. pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by many Fusarium species, including F. verticillioides, inhibited the production of DAPG by Pseudomonas spp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis of F. verticillioides by Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressed F. verticillioides due to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression of Fusarium spp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism. PMID:26655755

  20. Genetic characterization of hybridization and introgression between anadromous rainbow trout (oncorhynchus mykiss irideus) and coastal cutthroat trout (o. clarki clarki)

    USGS Publications Warehouse

    Young, W.P.; Ostberg, C.O.; Keim, P.; Thorgaard, G.H.

    2001-01-01

    Interspecific hybridization represents a dynamic evolutionary phenomenon and major conservation problem in salmonid fishes. In this study we used amplified fragment length polymorphisms (AFLP) and mitochondrial DNA (mtDNA) markers to describe the extent and characterize the pattern of hybridization and introgression between coastal rainbow trout (Oncorhynchus mykiss irideus) and coastal cutthroat trout (O. clarki clarki). Hybrid individuals were initially identified using principle coordinate analysis of 133 polymorphic AFLP markers. Subsequent analysis using 23 diagnostic AFLP markers revealed the presence of F1, rainbow trout backcross, cutthroat trout backcross and later-generation hybrids. mtDNA analysis demonstrated equal numbers of F1 hybrids with rainbow and cutthroat trout mtDNA indicating reciprocal mating of the parental types. In contrast, rainbow and cutthroat trout backcross hybrids always exhibited the mtDNA from the recurrent parent, indicating a male hybrid mating with a pure female. This study illustrates the usefulness of the AFLP technique for generating large numbers of species diagnostic markers. The pattern of hybridization raises many questions concerning the existence and action of reproductive isolating mechanisms between these two species. Our findings are consistent with the hypothesis that introgression between anadromous populations of coastal rainbow and coastal cutthroat trout is limited by an environment-dependent reduction in hybrid fitness.

  1. Allelotype analysis of chemically induced squamous cell carcinomas in F(1) hybrids of two inbred mouse strains with different susceptibility to tumor progression.

    PubMed

    Stern, M C; Benavides, F; Klingelberger, E A; Conti, C J

    2000-07-01

    Loss of heterozygosity (LOH) at specific chromosomal loci is generally considered indirect evidence for the presence of putative suppressor genes. Allelotyping of tumors using polymorphic markers distributed throughout the entire genome allows the analysis of specific allelic losses. In the field of chemical carcinogenesis, the outbred SENCAR mouse has been commonly used to analyze the multistage nature of skin tumor development. In the study reported here we generated F(1) hybrids between two inbred strains (SENCARB/Pt and SSIN/Sprd) derived from the SENCAR stock that differ in their susceptibility to tumor progression. We typed 24 7, 12-dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate-induced squamous cell carcinomas for LOH using 56 microsatellite markers distributed among all autosomal chromosomes. The highest percentage of LOH, 78%, was found on chromosome 7, but there was no preferential loss of one particular allele, indicating that the putative suppressor genes found in this area are not involved in genetic susceptibility. High levels of LOH were also found on chromosomes 16 (39%), 6 (29%), 4 (25%), 9 (25%), 14 (22%), 10 (20%) and 19 (20%), but with no preferential loss of the alleles of one strain. The chromosomal regions with LOH on mouse chromosomes 4, 6, 7, 9, 10, 14, 16 and 19 correspond to regions in the human genome where LOH has been reported and have been suggested to harbor tumor suppressor genes.

  2. Genotype, soil type, and locale effects on reciprocal transplant vigor, endophyte growth, and microbial functional diversity of a narrow sagebrush hybrid zone in Salt Creek Canyon, Utah

    USGS Publications Warehouse

    Miglia, K.J.; McArthur, E.D.; Redman, R.S.; Rodriguez, R.J.; Zak, J.C.; Freeman, D.C.

    2007-01-01

    When addressing the nature of ecological adaptation and environmental factors limiting population ranges and contributing to speciation, it is important to consider not only the plant's genotype and its response to the environment, but also any close interactions that it has with other organisms, specifically, symbiotic microorganisms. To investigate this, soils and seedlings were reciprocally transplanted into common gardens of the big sagebrush hybrid zone in Salt Creek Canyon, Utah, to determine location and edaphic effects on the fitness of parental and hybrid plants. Endophytic symbionts and functional microbial diversity of indigenous and transplanted soils and sagebrush plants were also examined. Strong selection occurred against the parental genotypes in the middle hybrid zone garden in middle hybrid zone soil; F1 hybrids had the highest fitness under these conditions. Neither of the parental genotypes had superior fitness in their indigenous soils and habitats; rather F1 hybrids with the nonindigenous maternal parent were superiorly fit. Significant garden-by-soil type interactions indicate adaptation of both plant and soil microorganisms to their indigenous soils and habitats, most notably in the middle hybrid zone garden in middle hybrid zone soil. Contrasting performances of F1 hybrids suggest asymmetrical gene flow with mountain, rather than basin, big sagebrush acting as the maternal parent. We showed that the microbial community impacted the performance of parental and hybrid plants in different soils, likely limiting the ranges of the different genotypes.

  3. Genetic loci with parent-of-origin effects cause hybrid seed lethality in crosses between Mimulus species.

    PubMed

    Garner, Austin G; Kenney, Amanda M; Fishman, Lila; Sweigart, Andrea L

    2016-07-01

    In flowering plants, F1 hybrid seed lethality is a common outcome of crosses between closely related diploid species, but the genetic basis of this early-acting and potentially widespread form of postzygotic reproductive isolation is largely unknown. We intercrossed two closely related species of monkeyflower, Mimulus guttatus and Mimulus tilingii, to characterize the mechanisms and strength of postzygotic reproductive isolation. Then, using a reciprocal backcross design, we performed high-resolution genetic mapping to determine the genetic architecture of hybrid seed lethality and directly test for loci with parent-of-origin effects. We found that F1 hybrid seed lethality is an exceptionally strong isolating barrier between Mimulus species, with reciprocal crosses producing < 1% viable seeds. This form of postzygotic reproductive isolation appears to be highly polygenic, indicating that multiple incompatibility loci have accumulated rapidly between these closely related Mimulus species. It is also primarily caused by genetic loci with parent-of-origin effects, suggesting a possible role for imprinted genes in the evolution of Mimulus hybrid seed lethality. Our findings suggest that divergence in loci with parent-of-origin effects, which is probably driven by genomic coevolution within lineages, might be an important source of hybrid incompatibilities between flowering plant species. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  4. Transposable Element Misregulation Is Linked to the Divergence between Parental piRNA Pathways in Drosophila Hybrids.

    PubMed

    Romero-Soriano, Valèria; Modolo, Laurent; Lopez-Maestre, Hélène; Mugat, Bruno; Pessia, Eugénie; Chambeyron, Séverine; Vieira, Cristina; Garcia Guerreiro, Maria Pilar

    2017-06-01

    Interspecific hybridization is a genomic stress condition that leads to the activation of transposable elements (TEs) in both animals and plants. In hybrids between Drosophila buzzatii and Drosophila koepferae, mobilization of at least 28 TEs has been described. However, the molecular mechanisms underlying this TE release remain poorly understood. To give insight on the causes of this TE activation, we performed a TE transcriptomic analysis in ovaries (notorious for playing a major role in TE silencing) of parental species and their F1 and backcrossed (BC) hybrids. We find that 15.2% and 10.6% of the expressed TEs are deregulated in F1 and BC1 ovaries, respectively, with a bias toward overexpression in both cases. Although differences between parental piRNA (Piwi-interacting RNA) populations explain only partially these results, we demonstrate that piRNA pathway proteins have divergent sequences and are differentially expressed between parental species. Thus, a functional divergence of the piRNA pathway between parental species, together with some differences between their piRNA pools, might be at the origin of hybrid instabilities and ultimately cause TE misregulation in ovaries. These analyses were complemented with the study of F1 testes, where TEs tend to be less expressed than in D. buzzatii. This can be explained by an increase in piRNA production, which probably acts as a defence mechanism against TE instability in the male germline. Hence, we describe a differential impact of interspecific hybridization in testes and ovaries, which reveals that TE expression and regulation are sex-biased. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  5. Nonadditive protein accumulation patterns in Maize (Zea mays L.) hybrids during embryo development.

    PubMed

    Marcon, Caroline; Schützenmeister, André; Schütz, Wolfgang; Madlung, Johannes; Piepho, Hans-Peter; Hochholdinger, Frank

    2010-12-03

    Heterosis describes the superior performance of heterozygous F(1)-hybrid plants compared to their homozygous parental inbred lines. In the present study, heterosis was detected for length, weight, and the time point of seminal root primordia initiation in maize (Zea mays L.) embryos of the reciprocal F(1)-hybrids UH005xUH250 and UH250xUH005. A two-dimensional gel electrophoresis (2-DE) proteome survey of the most abundant proteins of the reciprocal hybrids and their parental inbred lines 25 and 35 days after pollination revealed that 141 of 597 detected proteins (24%) exhibited nonadditive accumulation in at least one hybrid. Approximately 44% of all nonadditively accumulated proteins displayed an expression pattern that was not distinguishable from the low parent value. Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) analyses and subsequent functional classification of the 141 proteins revealed that development, protein metabolism, redox-regulation, glycolysis, and amino acid metabolism were the most prominent functional classes among nonadditively accumulated proteins. In 35-day-old embryos of the hybrid UH250xUH005, a significant up-regulation of enzymes related to glucose metabolism which often exceeded the best parent values was observed. A comparison of nonadditive protein accumulation between rice and maize embryo data sets revealed a significant overlap of nonadditively accumulated proteins suggesting conserved organ- or tissue-specific regulatory mechanisms in monocots related to heterosis.

  6. Defect Structures of La1 - y Sr y F3 - y , La1 - y Ba y F3 - y , and Nd1 - y Ca y F3 - y ( y = 0.05, 0.10) Nonstoichiometric Tysonite Phases

    NASA Astrophysics Data System (ADS)

    Chernaya, T. S.; Verin, I. A.; Khrykina, O. N.; Bolotina, N. B.

    2018-01-01

    Characteristic features of defect structures of La1 - y Sr y F3 - y , La1 - y Ba y F3 - y , and Nd1 - y Ca y F3 - y ( y = 0.05, 0.10) nonstoichiometric phases of different compositions are determined from X-ray diffraction data. Interest in subtle details of their structure is determined by the possibility of ion transport over fluorine vacancies and by a strong compositional dependence of the ionic conductivity. The La0.95Sr0.05F2.95, La0.95Ba0.05F2.95, and Nd0.95Ca0.05F2.95 phases, as well as the La0.9Ba0.1F2.9 phase, crystallize as β-LaF3 (sp. gr. P3̅c1, Z = 6). The La0.9Sr0.1F2.9 and Nd0.9Ca0.1F2.9 phases lose their superstructure and are described by a cell whose volume is three times smaller (sp. gr. P63/ mmc, Z = 2). Defects of crystal structure R1 - y M y F3 - y are not exhausted by vacancies in fluorine positions. All crystals with a "large" cell are twinned according to the merohedral twin law. The majority of atomic positions in models with a "small" cell are split by group symmetry elements and are occupied statistically.

  7. Molecular Evidence for Natural Hybridization between Cotoneaster dielsianus and C. glaucophyllus

    PubMed Central

    Li, Mingwan; Chen, Sufang; Zhou, Renchao; Fan, Qiang; Li, Feifei; Liao, Wenbo

    2017-01-01

    Hybridization accompanied by polyploidization and apomixis has been demonstrated as a driving force in the evolution and speciation of many plants. A good example to study the evolutionary process of hybridization associated with polyploidy and apomixis is the genus Cotoneaster (Rosaceae), which includes approximately 150 species, most of which are polyploid apomicts. In this study, we investigated all Cotoneaster taxa distributed in a small region of Malipo, Yunnan, China. Based on the morphological characteristics, four Cotoneaster taxa were identified and sampled: C. dielsianus, C. glaucophyllus, C. franchetii, and a putative hybrid. Flow cytometry analyses showed that C. glaucophyllus was diploid, while the other three taxa were tetraploid. A total of five low-copy nuclear genes and six chloroplast regions were sequenced to validate the status of the putative hybrid. Sequence analyses showed that C. dielsianus and C. glaucophyllus are distantly related and they could be well separated using totally 50 fixed nucleotide substitutions and four fixed indels at the 11 investigated genes. All individuals of the putative hybrid harbored identical sequences: they showed chromatogram additivity for all fixed differences between C. dielsianus and C. glaucophyllus at the five nuclear genes, and were identical with C. glaucophyllus at the six chloroplast regions. Haplotype analysis revealed that C. dielsianus possessed nine haplotypes for the 11 genes, while C. glaucophyllus had ten, and there were no shared haplotypes between the two species. The putative hybrid harbored two haplotypes for each nuclear gene: one shared with C. dielsianus and the other with C. glaucophyllus. They possessed the same chloroplast haplotype with C. glaucophyllus. Our study provided convincing evidence for natural hybridization between C. dielsianus and C. glaucophyllus, and revealed that all hybrid individuals were derivatives of one initial F1 via apomixes. C. glaucophyllus served as the

  8. Phylogenomic evidence for ancient hybridization in the genomes of living cats (Felidae)

    PubMed Central

    Li, Gang; Davis, Brian W.; Eizirik, Eduardo; Murphy, William J.

    2016-01-01

    Inter-species hybridization has been recently recognized as potentially common in wild animals, but the extent to which it shapes modern genomes is still poorly understood. Distinguishing historical hybridization events from other processes leading to phylogenetic discordance among different markers requires a well-resolved species tree that considers all modes of inheritance and overcomes systematic problems due to rapid lineage diversification by sampling large genomic character sets. Here, we assessed genome-wide phylogenetic variation across a diverse mammalian family, Felidae (cats). We combined genotypes from a genome-wide SNP array with additional autosomal, X- and Y-linked variants to sample ∼150 kb of nuclear sequence, in addition to complete mitochondrial genomes generated using light-coverage Illumina sequencing. We present the first robust felid time tree that accounts for unique maternal, paternal, and biparental evolutionary histories. Signatures of phylogenetic discordance were abundant in the genomes of modern cats, in many cases indicating hybridization as the most likely cause. Comparison of big cat whole-genome sequences revealed a substantial reduction of X-linked divergence times across several large recombination cold spots, which were highly enriched for signatures of selection-driven post-divergence hybridization between the ancestors of the snow leopard and lion lineages. These results highlight the mosaic origin of modern felid genomes and the influence of sex chromosomes and sex-biased dispersal in post-speciation gene flow. A complete resolution of the tree of life will require comprehensive genomic sampling of biparental and sex-limited genetic variation to identify and control for phylogenetic conflict caused by ancient admixture and sex-biased differences in genomic transmission. PMID:26518481

  9. Hybrid parallelization of the XTOR-2F code for the simulation of two-fluid MHD instabilities in tokamaks

    NASA Astrophysics Data System (ADS)

    Marx, Alain; Lütjens, Hinrich

    2017-03-01

    A hybrid MPI/OpenMP parallel version of the XTOR-2F code [Lütjens and Luciani, J. Comput. Phys. 229 (2010) 8130] solving the two-fluid MHD equations in full tokamak geometry by means of an iterative Newton-Krylov matrix-free method has been developed. The present work shows that the code has been parallelized significantly despite the numerical profile of the problem solved by XTOR-2F, i.e. a discretization with pseudo-spectral representations in all angular directions, the stiffness of the two-fluid stability problem in tokamaks, and the use of a direct LU decomposition to invert the physical pre-conditioner at every Krylov iteration of the solver. The execution time of the parallelized version is an order of magnitude smaller than the sequential one for low resolution cases, with an increasing speedup when the discretization mesh is refined. Moreover, it allows to perform simulations with higher resolutions, previously forbidden because of memory limitations.

  10. Genome instability in Novel Lolium multiflorum x L. arundinaceum hybrids

    USDA-ARS?s Scientific Manuscript database

    We have identified a method whereby Lolium multiflorum (Lm) or L. arundinaceum (Fa) genomes are preferentially eliminated through a mitotic loss behavior in interspecific Lm x Fa F1 hybrids,generating either dihaploid Lm lines or Fa lines. The genome instability has been visualized phenotypically an...

  11. Mitochondrial Genome Variation after Hybridization and Differences in the First and Second Generation Hybrids of Bream Fishes

    PubMed Central

    Zhang, Wei-Zhuo; Xiong, Xue-Mei; Zhang, Xiu-Jie; Wan, Shi-Ming; Guan, Ning-Nan; Nie, Chun-Hong; Zhao, Bo-Wen; Hsiao, Chung-Der; Wang, Wei-Min; Gao, Ze-Xia

    2016-01-01

    Hybridization plays an important role in fish breeding. Bream fishes contribute a lot to aquaculture in China due to their economically valuable characteristics and the present study included five bream species, Megalobrama amblycephala, Megalobrama skolkovii, Megalobrama pellegrini, Megalobrama terminalis and Parabramis pekinensis. As maternal inheritance of mitochondrial genome (mitogenome) involves species specific regulation, we aimed to investigate in which way the inheritance of mitogenome is affected by hybridization in these fish species. With complete mitogenomes of 7 hybrid groups of bream species being firstly reported in the present study, a comparative analysis of 17 mitogenomes was conducted, including representatives of these 5 bream species, 6 first generation hybrids and 6 second generation hybrids. The results showed that these 17 mitogenomes shared the same gene arrangement, and had similar gene size and base composition. According to the phylogenetic analyses, all mitogenomes of the hybrids were consistent with a maternal inheritance. However, a certain number of variable sites were detected in all F1 hybrid groups compared to their female parents, especially in the group of M. terminalis (♀) × M. amblycephala (♂) (MT×MA), with a total of 86 variable sites between MT×MA and its female parent. Among the mitogenomes genes, the protein-coding gene nd5 displayed the highest variability. The number of variation sites was found to be related to phylogenetic relationship of the parents: the closer they are, the lower amount of variation sites their hybrids have. The second generation hybrids showed less mitogenome variation than that of first generation hybrids. The non-synonymous and synonymous substitution rates (dN/dS) were calculated between all the hybrids with their own female parents and the results indicated that most PCGs were under negative selection. PMID:27391325

  12. Development of PEGylated peptide probes conjugated with (18)F-labeled BODIPY for PET/optical imaging of MT1-MMP activity.

    PubMed

    Kondo, Naoya; Temma, Takashi; Deguchi, Jun; Sano, Kohei; Ono, Masahiro; Saji, Hideo

    2015-12-28

    Since the processing activity of the matrix metalloproteinase MT1-MMP regulates various cellular functions such as motility, invasion, growth, differentiation and apoptosis, precise in vivo evaluation of MT1-MMP activity in cancers can provide beneficial information for both basic and clinical studies. For this purpose, we designed a cleavable Positron Emission Tomography (PET)/optical imaging probe consisting of BODIPY650/665 and polyethylene glycol (PEG) conjugated to opposite ends of MT1-MMP substrate peptides. We used in vitro and in vivo fluorescence experiments to select suitable substrate peptide sequences and PEG sizes for the MT1-MMP probes and obtained an optimized structure referred to here as MBP-2k. Radiofluorinated MBP-2k ([(18)F]MBP-2k) was then successfully synthesized via an (18)F-(19)F isotopic exchange reaction in BODIPY650/665. After intravenous injection into mice with xenografted tumors, [(18)F]MBP-2k showed significantly higher accumulation in HT1080 tumors with high MT1-MMP activity than in A549 tumors that have low MT1-MMP activity. Moreover, PET images showed better contrast in HT1080 tumors. These results show that [(18)F]MBP-2k can be used as a hybrid PET/optical imaging agent and is a promising probe for non-invasive monitoring of MT1-MMP activity in cancers. This probe may also efficiently combine targeted tumor imaging with image-guided surgery that could be beneficial for patients in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Distant hybridization leads to different ploidy fishes.

    PubMed

    Liu, ShaoJun

    2010-04-01

    Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combination of this method with gynogenesis or androgenesis lead to different ploidy fishes with genetic variation, including fertile tetraploid hybrids, sterile triploid hybrids, fertile diploid hybrids, fertile diploid gynogenetic fish, and their derived progenies. The formations of the different ploidy fishes depend on the genetic relationship between the parents. In this study, several types of distant hybridization, including red crucian carp (Carassius auratus red var.) (2n=100, abbreviated as RCC) (female) x common carp (Cyprinus carpio L.) (2n=100, abbreviated as CC) (male), and RCC (2n=100) (female) x blunt snout bream (Megalobrama amblycephala) (2n=48, abbreviated as BSB) (male) are described. In the distant hybridization of RCC (female) x CC (male), bisexual fertile F(3)-F(18) allotetraploid hybrids (4n=200, abbreviated as 4nAT) were formed. The diploid hybrid eggs and diploid sperm generated by the females and males of 4nAT developed into diploid gynogenetic hybrids and diploid androgenetic hybrids, respectively, by gynogenesis and androgenesis, without treatment for doubling the chromosome. Improved tetraploid hybrids and improved diploid fishes with genetic variation were derived from the gynogenetic hybrid line. The improved diploid fishes included the high-body RCC and high-body goldfish. The formation of the tetraploid hybrids was related to the occurrence of unreduced gametes generated from the diploid hybrids, which involved in premeiotic endoreduplication, endomitosis, or fusion of germ cells. The sterile triploid hybrids (3n=150) were produced on a large scale by crossing the males of tetraploid hybrids with females of diploid fish (2n=100). In another distant hybridization of RCC (female) x BSB (male), different ploidy fishes were

  14. RECEPTOR AFFINITY AND PHOSPHODIESTERASES 4B AND 10A ACTIVITY OF OCTAHYDRO- AND 6,7-DIMETHOXY-3,4-DIHYDRO- ISOQUINOLIN-2(1H)-YL-ALKYL DERIVATIVES OF IMIDAZO- AND PYRIMIDINO[2,1-f]PURINES.

    PubMed

    Zagórska, Agnieszka; Gryzło, Beata; Satała, Grzegorz; Bojarski, Andrzej J; Głuch-Lutwin, Monika; Mordyl, Barbara; Kazek, Grzegorz; Pawłowski, Maciej

    2016-01-01

    A series of octahydro- and 6,7-dimethoxy-3,4-dihydro- isoquinolin-2(1H)-yl-alkyl derivatives of imidazo- and pyrimidino[2,1-f]purines were synthesized and biologically evaluated in in vitro competition binding experiments for serotonin 5-HT(1A), 5-HT(6), 5-HT(7), and dopamine D2 receptors and inhibitory potencies for phosphodiesterases - PDE4B1 and PDE10A. The structure-activity relationships allowed to determine the structural features responsible for receptor and enzyme activity. Compound 5 (8-(4-(6,7-dimethoxy-3,4-dihydroiso- quinolin-2(1H)butyl)1,3-dimethyl-H-imidazo[2,1-f]purine-2,4(3H,8H)-dione) could be regarded as promising structure for further modification and detailed mechanistic study for obtained hybrid ligands.

  15. Hybrid wireless-over-fiber transmission system based on multiple injection-locked FP LDs.

    PubMed

    Li, Chung-Yi; Lu, Hai-Han; Chu, Chien-An; Ying, Cheng-Ling; Lu, Ting-Chien; Peng, Peng-Chun

    2015-07-27

    A hybrid wireless-over-fiber (WoF) transmission system based on multiple injection-locked Fabry-Perot laser diodes (FP LDs) is proposed and experimentally demonstrated. Unlike the traditional hybrid WoF transmission systems that require multiple distributed feedback (DFB) LDs to support different kinds of services, the proposed system employs multiple injection-locked FP LDs to provide different kinds of applications. Such a hybrid WoF transmission system delivers downstream intensity-modulated 20-GHz microwave (MW)/60-GHz millimeter-wave (MMW)/550-MHz cable television (CATV) signals and upstream phase-remodulated 20-GHz MW signal. Excellent bit error rate (BER), carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple-beat (CTB) are observed over a 40-km single-mode fiber (SMF) and a 4-m radio frequency (RF) wireless transport. Such a hybrid WoF transmission system has practical applications for fiber-wireless convergence to provide broadband integrated services, including telecommunication, data communication, and CATV services.

  16. Routine intraoperative completion angiography after coronary artery bypass grafting and 1-stop hybrid revascularization results from a fully integrated hybrid catheterization laboratory/operating room.

    PubMed

    Zhao, David X; Leacche, Marzia; Balaguer, Jorge M; Boudoulas, Konstantinos D; Damp, Julie A; Greelish, James P; Byrne, John G; Ahmad, Rashid M; Ball, Stephen K; Cleator, John H; Deegan, Robert J; Eagle, Susan S; Fong, Pete P; Fredi, Joseph L; Hoff, Steven J; Jennings, Henry S; McPherson, John A; Piana, Robert N; Pretorius, Mias; Robbins, Mark A; Slosky, David A; Thompson, Annemarie

    2009-01-20

    This study sought to report our experience with a routine completion angiogram after coronary artery bypass surgery (CABG) and simultaneous (1-stop) percutaneous coronary intervention (PCI) at the time of CABG performed in the hybrid catheterization laboratory/operating room. The value of a routine completion angiogram after CABG and 1-stop hybrid CABG/PCI remains unresolved. Between April 2005 and July 2007, 366 consecutive patients underwent CABG surgery, with (n = 112) or without (n = 254) concomitant 1-stop PCI (hybrid), all with completion angiography before chest closure. Among the 112 1-stop hybrid CABG/PCI patients, 67 (60%) underwent a planned hybrid procedure based on pre-operative assessment, whereas 45 (40%) underwent open-chest PCI (unplanned hybrid) based on intraoperative findings. Among the 796 CABG grafts (345 left internal mammary artery, 12 right internal mammary artery/radial, and 439 veins), 97 (12%) angiographic defects were identified. Defects were repaired with either a minor adjustment of the graft (n = 22, 2.8%), with intraoperative open-chest PCI (unplanned hybrid, n = 48, 6%) or with traditional surgical revision (n = 27, 3.4%). Hybrid patients had clinical outcomes similar to standard CABG patients. Routine completion angiography detected 12% of grafts with important angiographic defects. One-stop hybrid coronary revascularization is reasonable, safe, and feasible. Combining the tools of the catheterization laboratory and operating room greatly enhances the options available to the surgeon and cardiologist for patients with complex coronary artery disease.

  17. Immune-Enhancing Effect of Nanometric Lactobacillus plantarum nF1 (nLp-nF1) in a Mouse Model of Cyclophosphamide-Induced Immunosuppression.

    PubMed

    Choi, Dae-Woon; Jung, Sun Young; Kang, Jisu; Nam, Young-Do; Lim, Seong-Il; Kim, Ki Tae; Shin, Hee Soon

    2018-02-28

    Nanometric Lactobacillus plantarum nF1 (nLp-nF1) is a biogenics consisting of dead L. plantarum cells pretreated with heat and a nanodispersion process. In this study, we investigated the immune-enhancing effects of nLp-nF1 in vivo and in vitro. To evaluate the immunostimulatory effects of nLp-nF1, mice immunosuppressed by cyclophosphamide (CPP) treatment were administered with nLp-nF1. As expected, CPP restricted the immune response of mice, whereas oral administration of nLp-nF1 significantly increased the total IgG in the serum, and cytokine production (interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α)) in bone marrow cells. Furthermore, nLp-nF1 enhanced the production of splenic cytokines such as IL-12, TNF-α, and interferon gamma (IFN-γ). In vitro, nLp-nF1 stimulated the immune response by enhancing the production of cytokines such as IL-12, TNF-α, and IFN-γ. Moreover, nLp-nF1 given a food additive enhanced the immune responses when combined with various food materials in vitro. These results suggest that nLp-nF1 could be used to strengthen the immune system and recover normal immunity in people with a weak immune system, such as children, the elderly, and patients.

  18. Experimental Crossing of Two Distinct Species of Leopard Geckos, Eublepharis angramainyu and E. macularius: Viability, Fertility and Phenotypic Variation of the Hybrids

    PubMed Central

    Jančúchová-Lásková, Jitka; Landová, Eva; Frynta, Daniel

    2015-01-01

    Hybridization between distinct species of animals and subsequent genetic introgression plays a considerable role in the speciation process and the emergence of adaptive characters. Fitness of between-species hybrids usually sharply decreases with the divergence time of the concerned species and the divergence depth, which still allows for a successful crossing differs among principal clades of vertebrates. Recently, a review of hybridization events among distinct lizard species revealed that lizards belong to vertebrates with a highly developed ability to hybridize. In spite of this, reliable reports of experimental hybridizations between genetically fairly divergent species are only exceptional. Here, we show the results of the crossing of two distinct allopatric species of eyelid geckos possessing temperature sex determination and lacking sex chromosomes: Eublepharis macularius distributed in Pakistan/Afghanistan area and E. angramainyu, which inhabits Mesopotamia and adjacent areas. We demonstrated that F1 hybrids were viable and fertile, and the introgression of E. angramainyu genes into the E. macularius genome can be enabled via a backcrossing. The examined hybrids (except those of the F2 generation) displayed neither malformations nor a reduced survival. Analyses of morphometric and coloration traits confirmed phenotypic distinctness of both parental species and their F1 hybrids. These findings contrast with long-term geographic and an evolutionary separation of the studied species. Thus, the occurrence of fertile hybrids of comparably divergent species, such as E. angramainyu and E. macularius, may also be expected in other taxa of squamates. This would violate the current estimates of species diversity in lizards. PMID:26633648

  19. General mechanism for the 1 /f noise

    NASA Astrophysics Data System (ADS)

    Yadav, Avinash Chand; Ramaswamy, Ramakrishna; Dhar, Deepak

    2017-08-01

    We consider the response of a memoryless nonlinear device that acts instantaneously, converting an input signal ξ (t ) into an output η (t ) at the same time t . For input Gaussian noise with power-spectrum 1 /fα , the nonlinearity can modify the spectral index of the output to give a spectrum that varies as 1 /fα ' with α'≠α . We show that the value of α' depends on the nonlinear transformation and can be tuned continuously. This provides a general mechanism for the ubiquitous 1 /f noise found in nature.

  20. Maternal inheritance of the chloroplast genome in Eucalyptus globulus and interspecific hybrids.

    PubMed

    Mckinnon, A E; Vaillancourt, R E; Tilyard, P A; Potts, B M

    2001-10-01

    The utility of chloroplast DNA (cpDNA) in Eucalyptus, either as a molecular marker for genetic studies or as a potential vehicle for genetic manipulation, is based on knowledge of its mode of inheritance. Chloroplast inheritance in angiosperms can vary among and within species, and anomalous inheritance has been reported in some interspecific-hybrid combinations. In Eucalyptus, abnormalities of pollen-tube growth occur in a number of interspecific-hybrid combinations, and this might increase the likelihood of anomalous chloroplast transmission. We used a rapid PCR technique to determine chloroplast heritability in 425 progeny of Eucalyptus, comprising 194 progeny of the premier pulpwood species E. globulus and 231 interspecific hybrids between E. globulus and E. nitens (F1, F2, and backcrosses). At this sampling intensity, no pollen-mediated transmission of cpDNA was found in any of the 40 families tested. The results are discussed with reference to chloroplast engineering and the use of cpDNA as a seed-specific marker in phylogeographic studies of Eucalyptus.

  1. SU-F-J-172: Hybrid MR/CT Compatible Phantom for MR-Only Based Radiotherapy

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

    Kim, M; Lee, S; Song, K

    2016-06-15

    Purpose: Development of hybrid MR/CT compatible phantom was introduced to fully establish MR image only radiation treatment and this suggested technique using in-house developed hybrid MR/CT compatible phantom image would utilize to generate radiation treatment planning and perform dose calculation without multi-modal registration process or generation of pseudo CT. Methods: Fundamental characteristics for “hybrid MR/CT compatible phantom” was established: Relaxation times equivalent to human tissue, dielectric properties, homogeneous relaxation times, sufficient strength to fabricate a torso, ease of handling, a wide variety of density material for calibration, chemical and physical stability over an extended time. For this requirements, chemical componentmore » in each tested plug which would be tissue equivalent to human tissue on MR and CT image and production of phantom body and plug was performed. Chemical component has described below: Agaros, GdCl{sub 3}, NaN{sub 3}, NaCl, K{sub 2}Co{sub 3}, deionized-distilled water. Various mixture of chemical component to simulate human tissue on both MR and CT image was tested by measuring T1, T2 relaxation time and signal intensity (SI) on MR image and Hounsfield unit (HU) on CT and each value was compared. The hybrid MR/CT compatible phantom with 14 plugs was designed and has made. Total height and external diameter was decided by internal size of 32 channel MR head-coil. Results: Tissue-equivalent chemical component materials and hybrid MR/CT compatible phantom was developed. The range of T1, T2 relaxation time and SI on MR image, HU on CT was acquired and could be adjusted to correspond to simulated human tissue. Conclusion: Current result shows its possibility for MR-only based radiotherapy and the best mixing rate of chemical component for tissue-equivalent image on MR and CT was founded. However, additional technical issues remain to be overcome. Conversion of SI on MR image into HU and dose calculation

  2. Chemical disorder and 207Pb hyperfine fields in the magnetoelectric multiferroic Pb (F e1 /2S b1 /2 ) O3 and its solid solution with Pb (F e1 /2N b1 /2) O3

    NASA Astrophysics Data System (ADS)

    Zagorodniy, Yu. O.; Kuzian, R. O.; Kondakova, I. V.; Maryško, M.; Chlan, V.; Štěpánková, H.; Olekhnovich, N. M.; Pushkarev, A. V.; Radyush, Yu. V.; Raevski, I. P.; Zalar, B.; Laguta, V. V.; Stephanovich, V. A.

    2018-01-01

    We report on the results of magnetic susceptibility, electron paramagnetic resonance, and 207Pb nuclear magnetic resonance (NMR) studies of the magnetoelectric multiferroic Pb (F e1 /2S b1 /2 ) O3 (PFS) ceramic, as well as its solid solution with Pb (F e1 /2N b1 /2) O3 (PFN) of different degrees of the 1:1 ordering of magnetic F e3 + and nonmagnetic S b5 + ions. The ordering has been studied by x-ray diffraction (XRD) and NMR methods. In particular, two spectral lines, originating from the ordered and disordered regions, respectively, are resolved in the 207Pb NMR spectra. This demonstrates the presence of spatially heterogeneous ordering where ordered regions are embedded into a disordered matrix. Combining XRD and NMR data, we have determined both the long-range order parameter s and the volume fraction of ordered regions s' for all investigated samples. The values vary in the range s =0 -0.93 and s'=0 -1 . We have found that the 207Pb Fermi contact interaction strongly depends on the disorder in the Fe/Sb positions: whereas it reaches 7.08 MHz in the ordered lattice, it is almost zero in the disordered environment. These results are further supported by the studies of PFS-PFN solid solutions. The analysis of experimental data in terms of density functional theory reveals a noticeably higher hybridization between Pb 6s and Fe 3d orbitals in the ordered case. The ordering of magnetic and nonmagnetic ions has a strong impact on the magnetic properties of PFS, leading to a transformation of the long-range ordered antiferromagnetic phase in chemically ordered samples to the spin glass state already in partially (s =0.35 ) disordered specimens. In our opinion, the difference in the magnetic properties of PFN and PFS is related to the fact that PFN is completely disordered, in contrast to PFS, which is only partially disordered, with small ordered regions existing in the disordered matrix that prevent the percolation of the nearest-neighbor Fe-Fe exchange interaction

  3. Overcoming inter-subspecific hybrid sterility in rice by developing indica-compatible japonica lines

    PubMed Central

    Guo, Jie; Xu, Xiaomei; Li, Wentao; Zhu, Wenyin; Zhu, Haitao; Liu, Ziqiang; Luan, Xin; Dai, Ziju; Liu, Guifu; Zhang, Zemin; Zeng, Ruizhen; Tang, Guang; Fu, Xuelin; Wang, Shaokui; Zhang, Guiquan

    2016-01-01

    Rice (Oryza sativa L.) is an important staple crop. The exploitation of the great heterosis that exists in the inter-subspecific crosses between the indica and japonica rice has long been considered as a promising way to increase the yield potential. However, the male and female sterility frequently occurred in the inter-subspecific hybrids hampered the utilization of the heterosis. Here we report that the inter-subspecific hybrid sterility in rice is mainly affected by the genes at Sb, Sc, Sd and Se loci for F1 male sterility and the gene at S5 locus for F1 female sterility. The indica-compatible japonica lines (ICJLs) developed by pyramiding the indica allele (S-i) at Sb, Sc, Sd and Se loci and the neutral allele (S-n) at S5 locus in japonica genetic background through marker-assisted selection are compatible with indica rice in pollen fertility and in spikelet fertility. These results showed a great promise of overcoming the inter-subspecific hybrid sterility and exploiting the heterosis by developing ICJLs. PMID:27246799

  4. Overcoming inter-subspecific hybrid sterility in rice by developing indica-compatible japonica lines.

    PubMed

    Guo, Jie; Xu, Xiaomei; Li, Wentao; Zhu, Wenyin; Zhu, Haitao; Liu, Ziqiang; Luan, Xin; Dai, Ziju; Liu, Guifu; Zhang, Zemin; Zeng, Ruizhen; Tang, Guang; Fu, Xuelin; Wang, Shaokui; Zhang, Guiquan

    2016-06-01

    Rice (Oryza sativa L.) is an important staple crop. The exploitation of the great heterosis that exists in the inter-subspecific crosses between the indica and japonica rice has long been considered as a promising way to increase the yield potential. However, the male and female sterility frequently occurred in the inter-subspecific hybrids hampered the utilization of the heterosis. Here we report that the inter-subspecific hybrid sterility in rice is mainly affected by the genes at Sb, Sc, Sd and Se loci for F1 male sterility and the gene at S5 locus for F1 female sterility. The indica-compatible japonica lines (ICJLs) developed by pyramiding the indica allele (S-i) at Sb, Sc, Sd and Se loci and the neutral allele (S-n) at S5 locus in japonica genetic background through marker-assisted selection are compatible with indica rice in pollen fertility and in spikelet fertility. These results showed a great promise of overcoming the inter-subspecific hybrid sterility and exploiting the heterosis by developing ICJLs.

  5. Microsatellite loci for distinguishing spotted owls (Strix occidentalis), barred owls (Strix varia), and their hybrids

    USGS Publications Warehouse

    Funk, W. Chris; Mullins, Thomas D.; Forsman, Eric D.; Haig, Susan M.

    2007-01-01

    We identified four diagnostic microsatellite loci that distinguish spotted owls (Strix occidentalis), barred owls (Strix varia), F1 hybrids and backcrosses. Thirty-four out of 52 loci tested (65.4%) successfully amplified, and four of these loci (11.8%) had allele sizes that did not overlap between spotted and barred owls. The probability of correctly identifying a backcross with these four loci is 0.875. Genotyping potential hybrid owls with these markers revealed that field identifications were often wrong. Given the difficulty of identifying hybrids in the field, these markers will be useful for hybrid identification, law enforcement and spotted owl conservation.

  6. Fine mapping of S37, a locus responsible for pollen and embryo sac sterility in hybrids between Oryza sativa L. and O. glaberrima Steud.

    PubMed

    Shen, Yumin; Zhao, Zhigang; Ma, Hongyang; Bian, Xiaofeng; Yu, Yang; Yu, Xiaowen; Chen, Haiyuan; Liu, Linglong; Zhang, Wenwei; Jiang, Ling; Zhou, Jiawu; Tao, Dayun; Wan, Jianmin

    2015-11-01

    Hybrid sterility locus S37 between Oryza glaberrima and Oryza sativa results in both pollen and embryo sac sterility. Interspecific crossing between African cultivated rice Oryza glaberrima and Oryza sativa cultivars is hindered by hybrid sterility. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL)-S37 using Dianjingyou1 (DJY1) as the recipient parent and an African cultivated rice variety as the donor parent. Empty pollen and embryo sac sterility were observed in F1 hybrids between DJY1 and NIL-S37. Cytological analyses showed that pollen abortion in the F1 hybrids occurred at the late binucleate stage due to a failure of starch accumulation in pollen grains. In addition, partial abortion of the embryo sac in the F1 hybrid was observed during function megaspore developing into mature embryo sac. Molecular analysis revealed that the semi-sterility was largely caused by the abortion of male and female gametophytes carrying the S37 allele from DJY1. A population of 25,600 plants derived from the hybrid DJY1/NIL-S37 was developed to fine map S37. Based on the physical location of molecular markers, S37 locus was finally delimited to a region of 205 kb on the short arm of chromosome 1 in terms of reference sequences of cv. Nipponbare. Interestingly, an about 97-kb DNA segment was deleted in the NIL-S37 based on BAC clone information of O. glaberrima. Fifty-four open reading frames (ORF) were predicted in this 205-kb region of DJY1, whereas only 31 ORFs were in that of NIL-S37. These results are valuable for cloning of S37 gene and further breaking reproductive isolation between Oryza glaberrima and Oryza sativa cultivars, as well as marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

  7. On the origin of POU5F1

    PubMed Central

    2013-01-01

    Background Pluripotency is a fundamental property of early mammalian development but it is currently unclear to what extent its cellular mechanisms are conserved in vertebrates or metazoans. POU5F1 and POU2 are the two principle members constituting the class V POU domain family of transcription factors, thought to have a conserved role in the regulation of pluripotency in vertebrates as well as germ cell maintenance and neural patterning. They have undergone a complex pattern of evolution which is poorly understood and controversial. Results By analyzing the sequences of POU5F1, POU2 and their flanking genes, we provide strong indirect evidence that POU5F1 originated at least as early as a common ancestor of gnathostomes but became extinct in a common ancestor of teleost fishes, while both POU5F1 and POU2 survived in the sarcopterygian lineage leading to tetrapods. Less divergent forms of POU5F1 and POU2 appear to have persisted among cartilaginous fishes. Conclusions Our study resolves the controversial evolutionary relationship between teleost pou2 and tetrapod POU2 and POU5F1, and shows that class V POU transcription factors have existed at least since the common ancestor of gnathostome vertebrates. It provides a framework for elucidating the basis for the lineage-specific extinctions of POU2 and POU5F1. PMID:23659605

  8. Recent Transmission of a Novel Alphacoronavirus, Bat Coronavirus HKU10, from Leschenault's Rousettes to Pomona Leaf-Nosed Bats: First Evidence of Interspecies Transmission of Coronavirus between Bats of Different Suborders

    PubMed Central

    Lau, Susanna K. P.; Li, Kenneth S. M.; Tsang, Alan K. L.; Shek, Chung-Tong; Wang, Ming; Choi, Garnet K. Y.; Guo, Rongtong; Wong, Beatrice H. L.; Poon, Rosana W. S.; Lam, Carol S. F.; Wang, Sylvia Y. H.; Fan, Rachel Y. Y.; Chan, Kwok-Hung; Zheng, Bo-Jian

    2012-01-01

    Although coronaviruses are known to infect various animals by adapting to new hosts, interspecies transmission events are still poorly understood. During a surveillance study from 2005 to 2010, a novel alphacoronavirus, BatCoV HKU10, was detected in two very different bat species, Ro-BatCoV HKU10 in Leschenault's rousettes (Rousettus leschenaulti) (fruit bats in the suborder Megachiroptera) in Guangdong and Hi-BatCoV HKU10 in Pomona leaf-nosed bats (Hipposideros pomona) (insectivorous bats in the suborder Microchiroptera) in Hong Kong. Although infected bats appeared to be healthy, Pomona leaf-nosed bats carrying Hi-BatCoV HKU10 had lower body weights than uninfected bats. To investigate possible interspecies transmission between the two bat species, the complete genomes of two Ro-BatCoV HKU10 and six Hi-BatCoV HKU10 strains were sequenced. Genome and phylogenetic analyses showed that Ro-BatCoV HKU10 and Hi-BatCoV HKU10 represented a novel alphacoronavirus species, sharing highly similar genomes except in the genes encoding spike proteins, which had only 60.5% amino acid identities. Evolution of the spike protein was also rapid in Hi-BatCoV HKU10 strains from 2005 to 2006 but stabilized thereafter. Molecular-clock analysis dated the most recent common ancestor of all BatCoV HKU10 strains to 1959 (highest posterior density regions at 95% [HPDs], 1886 to 2002) and that of Hi-BatCoV HKU10 to 1986 (HPDs, 1956 to 2004). The data suggested recent interspecies transmission from Leschenault's rousettes to Pomona leaf-nosed bats in southern China. Notably, the rapid adaptive genetic change in BatCoV HKU10 spike protein by ∼40% amino acid divergence after recent interspecies transmission was even greater than the ∼20% amino acid divergence between spike proteins of severe acute respiratory syndrome-related Rhinolophus bat coronavirus (SARSr-CoV) in bats and civets. This study provided the first evidence for interspecies transmission of coronavirus between bats of

  9. Transpiration Response and Growth in Pearl Millet Parental Lines and Hybrids Bred for Contrasting Rainfall Environments

    PubMed Central

    Medina, Susan; Gupta, S. K.; Vadez, Vincent

    2017-01-01

    Under conditions of high vapor pressure deficit (VPD) and soil drying, restricting transpiration is an important avenue to gain efficiency in water use. The question we raise in this article is whether breeding for agro-ecological environments that differ for the rainfall have selected for traits that control plant water use. These are measured in pearl millet materials bred for zones varying in rainfall (8 combinations of parent and F1-hybrids, 18 F1-hybrids and then 40 F1-hybrids). In all cases, we found an agro-ecological variation in the slope of the transpiration response to increasing VPD, and parental line variation in the transpiration response to soil drying within hybrids/parent combinations. The hybrids adapted to lower rainfall had higher transpiration response curves than those from the highest rainfall zones, but showed no variation in how transpiration responded to soil drying. The genotypes bred for lower rainfall zones showed lower leaf area, dry matter, thicker leaves, root development, and exudation, than the ones bred for high rainfall zone when grown in the low VPD environment of the greenhouse, but there was no difference in their root length neither on the root/shoot index in these genotypes. By contrast, when grown under high VPD conditions outdoors, the lower rainfall hybrids had the highest leaf, tiller, and biomass development. Finally, under soil drying the genotypes from the lower rainfall accumulated less biomass than the ones from higher rainfall zone, and so did the parental lines compared to the hybrids. These differences in the transpiration response and growth clearly showed that breeding for different agro-ecological zones also bred for different genotype strategies in relation to traits related to plant water use. Highlights: • Variation in transpiration response reflected breeding for agro-ecological zones • Different growth strategies depended on the environmental conditions • Different ideotypes reflected rainfall

  10. Transpiration Response and Growth in Pearl Millet Parental Lines and Hybrids Bred for Contrasting Rainfall Environments.

    PubMed

    Medina, Susan; Gupta, S K; Vadez, Vincent

    2017-01-01

    Under conditions of high vapor pressure deficit (VPD) and soil drying, restricting transpiration is an important avenue to gain efficiency in water use. The question we raise in this article is whether breeding for agro-ecological environments that differ for the rainfall have selected for traits that control plant water use. These are measured in pearl millet materials bred for zones varying in rainfall (8 combinations of parent and F 1 -hybrids, 18 F 1 -hybrids and then 40 F 1 -hybrids). In all cases, we found an agro-ecological variation in the slope of the transpiration response to increasing VPD, and parental line variation in the transpiration response to soil drying within hybrids/parent combinations. The hybrids adapted to lower rainfall had higher transpiration response curves than those from the highest rainfall zones, but showed no variation in how transpiration responded to soil drying. The genotypes bred for lower rainfall zones showed lower leaf area, dry matter, thicker leaves, root development, and exudation, than the ones bred for high rainfall zone when grown in the low VPD environment of the greenhouse, but there was no difference in their root length neither on the root/shoot index in these genotypes. By contrast, when grown under high VPD conditions outdoors, the lower rainfall hybrids had the highest leaf, tiller, and biomass development. Finally, under soil drying the genotypes from the lower rainfall accumulated less biomass than the ones from higher rainfall zone, and so did the parental lines compared to the hybrids. These differences in the transpiration response and growth clearly showed that breeding for different agro-ecological zones also bred for different genotype strategies in relation to traits related to plant water use. Highlights : • Variation in transpiration response reflected breeding for agro-ecological zones • Different growth strategies depended on the environmental conditions • Different ideotypes reflected

  11. How to Build a Hybrid Neurofeedback Platform Combining EEG and fMRI

    PubMed Central

    Mano, Marsel; Lécuyer, Anatole; Bannier, Elise; Perronnet, Lorraine; Noorzadeh, Saman; Barillot, Christian

    2017-01-01

    Multimodal neurofeedback estimates brain activity using information acquired with more than one neurosignal measurement technology. In this paper we describe how to set up and use a hybrid platform based on simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), then we illustrate how to use it for conducting bimodal neurofeedback experiments. The paper is intended for those willing to build a multimodal neurofeedback system, to guide them through the different steps of the design, setup, and experimental applications, and help them choose a suitable hardware and software configuration. Furthermore, it reports practical information from bimodal neurofeedback experiments conducted in our lab. The platform presented here has a modular parallel processing architecture that promotes real-time signal processing performance and simple future addition and/or replacement of processing modules. Various unimodal and bimodal neurofeedback experiments conducted in our lab showed high performance and accuracy. Currently, the platform is able to provide neurofeedback based on electroencephalography and functional magnetic resonance imaging, but the architecture and the working principles described here are valid for any other combination of two or more real-time brain activity measurement technologies. PMID:28377691

  12. Conservation of the Red Kite Milvus milvus (Aves: Accipitriformes) Is Not Affected by the Establishment of a Broad Hybrid Zone with the Black Kite Milvus migrans migrans in Central Europe

    PubMed Central

    Matušík, Hynek; Pfeiffer, Thomas; Nachtigall, Winfried; Bizos, Jiří; Šimčíková, Daniela; Literák, Ivan

    2016-01-01

    Among Accipitriformes sensu stricto, only a few species have been reported to form hybrid zones; these include the red kite Milvus milvus and black kite Milvus migrans migrans. M. milvus is endemic to the western Palearctic and has an estimated total population of 20–24,000 breeding pairs. The species was in decline until the 1970s due to persecution and has declined again since the 1990s due to ingestion of rodenticide-treated baits, illegal poisoning and changes in agricultural practices, particularly in its core range. Whereas F1 M. milvus × M. migr. migrans hybrid offspring have been found, F2 and F3 hybrids have only rarely been reported, with low nesting success rates of F1 hybrids and partial hybrid sterility likely playing a role. Here, we analyzed the mitochondrial (CO1 and CytB) and nuclear (Myc) DNA loci of 184 M. milvus, 124 M. migr. migrans and 3 F1 hybrid individuals collected across central Europe. In agreement with previous studies, we found low heterozygosity in M. milvus regardless of locus. We found that populations of both examined species were characterized by a high gene flow within populations, with all of the major haplotypes distributed across the entire examined area. Few haplotypes displayed statistically significant aggregation in one region over another. We did not find mitochondrial DNA of one species in individuals with the plumage of the other species, except in F1 hybrids, which agrees with Haldane´s Rule. It remains to be investigated by genomic methods whether occasional gene flow occurs through the paternal line, as the examined Myc gene displayed only marginal divergence between M. milvus and M. migr. migrans. The central European population of M. milvus is clearly subject to free intraspecific gene flow, which has direct implications when considering the origin of individuals in M. milvus re-introduction programs. PMID:27463515

  13. Hybrid chemistry. Part 4: Discovery of etravirine-VRX-480773 hybrids as potent HIV-1 non-nucleoside reverse transcriptase inhibitors.

    PubMed

    Wan, Zheng-Yong; Tao, Yuan; Wang, Ya-Feng; Mao, Tian-Qi; Yin, Hong; Chen, Fen-Er; Piao, Hu-Ri; De Clercq, Erik; Daelemans, Dirk; Pannecouque, Christophe

    2015-08-01

    A novel series of etravirine-VRX-480773 hybrids were designed using structure-guided molecular hybridization strategy and fusing the pharmacophore templates of etravirine and VRX-480773. The anti-HIV-1 activity and cytotoxicity was evaluated in MT-4 cell cultures. The most active hybrid compound in this series, N-(2-chlorophenyl)-2-((4-(4-cyano-2,6-dimethylphenoxy)pyrimidin-2-yl)thio)acetamide 3d (EC50=0.24 , SI>1225), was more potent than delavirdine (EC50=0.66 μM, SI>67) in the anti-HIV-1 in vitro cellular assay. Studies of structure-activity relationships established a correlation between anti-HIV activity and the substitution pattern of the acetanilide group. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Preparation of an amide group-connected graphene-polyaniline nanofiber hybrid and its application in supercapacitors.

    PubMed

    Jianhua, Liu; Junwei, An; Yecheng, Zhou; Yuxiao, Ma; Mengliu, Li; Mei, Yu; Songmei, Li

    2012-06-27

    Polyaniline (PANI) nanofiber is grafted onto graphene to obtain a novel graphene-polyaniline (GP) hybrid. Graphene is activated using SOCl2 and reacts with PANI to form an amide group that intimately connects graphene and PANI. The existence of the amide group and its anchoring effect in the GP hybrid are confirmed and characterized by SEM, TEM, FT-IR, Raman, XPS and quantum chemistry analyses. Electrochemical tests reveal that the GP hybrid has high capacitance performances of 579.8 and 361.9 F g(-1) at current densities of 0.3 and 1 A g(-1). These values indicate superiority to materials interacted by van der Waals force. Long-term charge/discharge tests at high current densities show that the GP hybrid preserves 96% of its initial capacitance, demonstrating good electrochemical stability. The improved electrochemical performance suggests promising application of the GP hybrid in high-performance supercapacitors.

  15. The Fusobacterium nucleatum Outer Membrane Protein RadD Is an Arginine-Inhibitable Adhesin Required for Inter-Species Adherence and the Structured Architecture of Multi-Species Biofilm

    PubMed Central

    Kaplan, Christopher W.; Lux, Renate; Haake, Susan Kinder; Shi, Wenyuan

    2009-01-01

    Summary A defining characteristic of the suspected periodontal pathogen Fusobacterium nucleatum is its ability to adhere to a plethora of oral bacteria. This distinguishing feature is suggested to play an important role in oral biofilm formation and pathogenesis, with fusobacteria proposed to serve as central “bridging organisms” in the architecture of the oral biofilm bringing together species which would not interact otherwise. Previous studies indicate that these bacterial interactions are mediated by galactose- or arginine-inhibitable adhesins although genetic evidence for the role and nature of these proposed adhesins remains elusive. To characterize these adhesins at the molecular level, the genetically transformable F. nucleatum strain ATCC 23726 was screened for adherence properties, and arginine inhibitable adhesion was evident, while galactose-inhibitable adhesion was not detected. Six potential arginine binding proteins were isolated from the membrane fraction of F. nucleatum ATCC 23726 and identified via mass spectroscopy as members of the outer membrane family of proteins in F. nucleatum. Inactivation of the genes encoding these six candidates for arginine-inhibitable adhesion and two additional homologues revealed that only a mutant derivative carrying an insertion in Fn1526 (now designated as radD) demonstrated significantly decreased co-aggregation with representatives of the Gram-positive “early oral colonizers”. Lack of the 350 kDa outer membrane protein encoded by radD resulted in the failure to form the extensive structured biofilm observed with the parent strain when grown in the presence of Streptococcus sanguinis ATCC 10556. These findings indicate that radD is responsible for arginine-inhibitable adherence of F. nucleatum and provides definitive molecular evidence that F. nucleatum adhesins play a vital role in inter-species adherence and multispecies biofilm formation. PMID:19007407

  16. Evolution in situ: hybrid origin and establishment of willows (Salix L.) on alpine glacier forefields

    PubMed Central

    Gramlich, S; Sagmeister, P; Dullinger, S; Hadacek, F; Hörandl, E

    2016-01-01

    Little attention has been paid to the evolutionary consequences of the colonizing dynamics and succession processes following glacier retreat. Here we studied hybrid populations that have recently formed and established on glacier forefields of the European Alps owing to secondary contact of a lowland colonizer with a subalpine species. We analyzed the composition of two hybrid populations between Salix purpurea and Salix helvetica with nine microsatellite markers by using Bayesian methods (structure and NewHybrids), and simulations. We also studied niche differentiation between the hybrids and the parental species based on indicator values, soil pH and water retention potential measurements. Allelic structure of hybrids confirms the assumed parentage and in situ origin of the crosses on two independent sites within the last decades. Both hybrid populations comprised F1 and later generation hybrids (F2 and backcrosses), confirming hybrid fertility. The parental species showed significant differences in niche characteristics for temperature, soil pH, nutrients and moisture. Remarkably, the hybrids exhibited a higher tolerance to cold temperatures, nutrient-poor and acidic soils than either parent. Our results show that willow hybrids originated after glacier retreat and have established persistent populations within a few decades. One factor contributing to hybrid establishment in sympatry with their parents is their ability to occupy more extreme niches than either parental species within a mosaic-like pattern of microhabitats on the forefield. Introgression and/or transgressive segregation may have resulted in novel genotypes that are able to expand the ecological spectrum of either parent. PMID:26980342

  17. A Role for CHH Methylation in the Parent-of-Origin Effect on Altered Circadian Rhythms and Biomass Heterosis in Arabidopsis Intraspecific Hybrids[W][OPEN

    PubMed Central

    Ng, Danny W.-K.; Miller, Marisa; Yu, Helen H.; Huang, Tien-Yu; Kim, Eun-Deok; Lu, Jie; Xie, Qiguang; McClung, C. Robertson; Chen, Z. Jeffrey

    2014-01-01

    Hybrid plants and animals often show increased levels of growth and fitness, a phenomenon known as hybrid vigor or heterosis. Circadian rhythms optimize physiology and metabolism in plants and animals. In plant hybrids and polyploids, expression changes of the genes within the circadian regulatory network, such as CIRCADIAN CLOCK ASSOCIATED1 (CCA1), lead to heterosis. However, the relationship between allelic CCA1 expression and heterosis has remained elusive. Here, we show a parent-of-origin effect on altered circadian rhythms and heterosis in Arabidopsis thaliana F1 hybrids. This parent-of-origin effect on biomass heterosis correlates with altered CCA1 expression amplitudes, which are associated with methylation levels of CHH (where H = A, T, or C) sites in the promoter region. The direction of rhythmic expression and hybrid vigor is reversed in reciprocal F1 crosses involving mutants that are defective in the RNA-directed DNA methylation pathway (argonaute4 and nuclear RNA polymerase D1a) but not in the maintenance methylation pathway (methyltransferase1 and decrease in DNA methylation1). This parent-of-origin effect on circadian regulation and heterosis is established during early embryogenesis and maintained throughout growth and development. PMID:24894042

  18. Molecular evidence for interspecies transmission of H3N2pM/H3N2v influenza A viruses at an Ohio agricultural fair, July 2012

    PubMed Central

    Bowman, Andrew S; Sreevatsan, Srinand; Killian, Mary L; Page, Shannon L; Nelson, Sarah W; Nolting, Jacqueline M; Cardona, Carol; Slemons, Richard D

    2012-01-01

    Evidence accumulating in 2011–2012 indicates that there is significant intra- and inter-species transmission of influenza A viruses at agricultural fairs, which has renewed interest in this unique human/swine interface. Six human cases of influenza A (H3N2) variant (H3N2v) virus infections were epidemiologically linked to swine exposure at fairs in the United States in 2011. In 2012, the number of H3N2v cases in the Midwest had exceeded 300 from early July to September, 2012. Prospective influenza A virus surveillance among pigs at Ohio fairs resulted in the detection of H3N2pM (H3N2 influenza A viruses containing the matrix (M) gene from the influenza A (H1N1) pdm09 virus). These H3N2pM viruses were temporally and spatially linked to several human H3N2v cases. Complete genomic analyses of these H3N2pM isolates demonstrated >99% nucleotide similarity to the H3N2v isolates recovered from human cases. Actions to mitigate the bidirectional interspecies transmission of influenza A virus between people and animals at agricultural fairs may be warranted. PMID:26038404

  19. Impact of velocity space distribution on hybrid kinetic-magnetohydrodynamic simulation of the (1,1) mode

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

    Kim, Charlson C.

    2008-07-15

    Numeric studies of the impact of the velocity space distribution on the stabilization of (1,1) internal kink mode and excitation of the fishbone mode are performed with a hybrid kinetic-magnetohydrodynamic model. These simulations demonstrate an extension of the physics capabilities of NIMROD[C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004)], a three-dimensional extended magnetohydrodynamic (MHD) code, to include the kinetic effects of an energetic minority ion species. Kinetic effects are captured by a modification of the usual MHD momentum equation to include a pressure tensor calculated from the {delta}f particle-in-cell method [S. E. Parker and W. W. Lee,more » Phys. Fluids B 5, 77 (1993)]. The particles are advanced in the self-consistent NIMROD fields. We outline the implementation and present simulation results of energetic minority ion stabilization of the (1,1) internal kink mode and excitation of the fishbone mode. A benchmark of the linear growth rate and real frequency is shown to agree well with another code. The impact of the details of the velocity space distribution is examined; particularly extending the velocity space cutoff of the simulation particles. Modestly increasing the cutoff strongly impacts the (1,1) mode. Numeric experiments are performed to study the impact of passing versus trapped particles. Observations of these numeric experiments suggest that assumptions of energetic particle effects should be re-examined.« less

  20. Integrated whole-body PET/MR imaging with 18F-FDG, 18F-FDOPA, and 18F-fluorodopamine in paragangliomas, in comparison to PET/CT: NIH first clinical experience with a single-injection, dual-modality imaging protocol

    PubMed Central

    Blanchet, Elise M.; Millo, Corina; Martucci, Victoria; Maass-Moreno, Roberto; Bluemke, David A.; Pacak, Karel

    2017-01-01

    Purpose Paragangliomas (PGLs) are tumors that can metastasize and recur; therefore, lifelong imaging follow-up is required. Hybrid positron emission tomography (PET)/computed tomography (/CT) is an essential tool to image PGLs. Novel hybrid PET/magnetic resonance (/MR) scanners are currently being studied in clinical oncology. We studied the feasibility of simultaneous whole-body PET/MR imaging to evaluate patients with PGLs. Methods Fifty-three PGLs or PGL-related lesions from eight patients were evaluated. All patients underwent a single-injection, dual-modality imaging protocol consisting of a PET/CT and subsequent PET/MR scan. Four patients were evaluated with 18F-fluorodeoxyglucose (18F-FDG), two with 18F-fluorodihydroxyphenylalanine (18F-FDOPA), and two with 18F-fluorodopamine (18F-FDA). PET/MR data were acquired using a hybrid whole-body 3-Tesla integrated PET/MR scanner. PET and MR data (DIXON images for attenuation correction and T2-weighted sequences for anatomic allocation) were acquired simultaneously. Imaging workflow and imaging times were documented. PET/MR and PET/CT data were visually assessed (blindly) in regards to image quality, lesion detection, and anatomic allocation and delineation of the PET findings. Results With hybrid PET/MR, we obtained high quality images in an acceptable acquisition time (median: 31 min, range: 25–40 min) with good patient compliance. A total of 53 lesions, located in the head-and-neck area (6), mediastinum (2), abdomen and pelvis (13), lungs (2), liver (4), and bone (26) were evaluated. 51 lesions were detected with PET/MR and confirmed by PET/CT. Two bone lesions (L4 body (8 mm) and sacrum (6 mm)) were not detectable on an 18F-FDA scan PET/MR, likely due to washout of the 18F-FDA. Co-registered MR tended to be superior to co-registered CT for head-and-neck, abdomen, pelvis, and liver lesions for anatomic allocation and delineation. Conclusions Clinical PGL evaluation with hybrid PET/MR is feasible with high image

  1. High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites

    NASA Astrophysics Data System (ADS)

    Li, Zijiong; Zhou, Zhihua; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng

    2013-11-01

    In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g-1 at a scan rate of 5 mV.s-1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors.

  2. Interspecies chimeric complementation for the generation of functional human tissues and organs in large animal hosts.

    PubMed

    Wu, Jun; Izpisua Belmonte, Juan Carlos

    2016-06-01

    The past decade's rapid progress in human pluripotent stem cell (hPSC) research has generated hope for meeting the rising demand of organ donation, which remains the only effective cure for end-stage organ failure, a major cause of death worldwide. Despite the potential, generation of transplantable organs from hPSCs using in vitro differentiation is far-fetched. An in vivo interspecies chimeric complementation strategy relying on chimeric-competent hPSCs and zygote genome editing provides an auspicious alternative for providing unlimited organ source for transplantation.

  3. Bighorn sheep × domestic sheep hybrids survive Mannheimia haemolytica challenge in the absence of vaccination.

    PubMed

    Subramaniam, R; Shanthalingam, S; Bavananthasivam, J; Kugadas, A; Raghavan, B; Batra, S A; Herndon, C N; Rodriguez, J; Tibary, A; Nelson, D; Potter, K A; Foreyt, W J; Srikumaran, S

    2014-06-04

    Bighorn sheep (BHS, Ovis canadensis) are much more susceptible than domestic sheep (DS, Ovis aries) to pneumonia caused by leukotoxin (Lkt)-producing members of the Family Pasteurellaceae, particularly Mannheimia haemolytica and Bibersteinia trehalosi. Leukotoxin is widely accepted as the critical virulence factor of these bacteria since Lkt-negative mutants do not cause death of BHS. Typically, DS carry Lkt-positive M. haemolytica and/or B. trehalosi as commensal bacteria in their nasopharynx. In contrast, most BHS do not carry Lkt-positive M. haemolytica or B. trehalosi, or carry Lkt-negative strains in their nasopharynx. In previous studies, we demonstrated that unimmunized DS resist M. haemolytica challenge while BHS succumb to it. We hypothesized that Lkt-neutralizing antibodies, induced by Lkt-positive M. haemolytica and/or B. trehalosi innately carried by DS in their nasopharynx, render them less susceptible to infection by these bacteria. In this study we developed BHS×DS F1 hybrids by artificial insemination of domestic ewes with BHS semen. F1 hybrids were fertile, and produced F2 hybrids and back-crosses. The F1, F2, and back-crosses were raised together with domestic ewes. All these animals acquired Lkt-positive M. haemolytica and/or B. trehalosi, and developed high titers of Lkt-neutralizing antibodies in the absence of vaccination. Furthermore, all of these animals resisted challenge with lethal dose of M. haemolytica. These results suggest that lack of previous exposure to Lkt is at least partially responsible for fatal pneumonia in BHS when they acquire Lkt-positive M. haemolytica and/or B. trehalosi from DS when the two species commingle. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Hybrid metric-Palatini stars

    NASA Astrophysics Data System (ADS)

    Danilǎ, Bogdan; Harko, Tiberiu; Lobo, Francisco S. N.; Mak, M. K.

    2017-02-01

    We consider the internal structure and the physical properties of specific classes of neutron, quark and Bose-Einstein condensate stars in the recently proposed hybrid metric-Palatini gravity theory, which is a combination of the metric and Palatini f (R ) formalisms. It turns out that the theory is very successful in accounting for the observed phenomenology, since it unifies local constraints at the Solar System level and the late-time cosmic acceleration, even if the scalar field is very light. In this paper, we derive the equilibrium equations for a spherically symmetric configuration (mass continuity and Tolman-Oppenheimer-Volkoff) in the framework of the scalar-tensor representation of the hybrid metric-Palatini theory, and we investigate their solutions numerically for different equations of state of neutron and quark matter, by adopting for the scalar field potential a Higgs-type form. It turns out that the scalar-tensor definition of the potential can be represented as an Clairaut differential equation, and provides an explicit form for f (R ) given by f (R )˜R +Λeff, where Λeff is an effective cosmological constant. Furthermore, stellar models, described by the stiff fluid, radiation-like, bag model and the Bose-Einstein condensate equations of state are explicitly constructed in both general relativity and hybrid metric-Palatini gravity, thus allowing an in-depth comparison between the predictions of these two gravitational theories. As a general result it turns out that for all the considered equations of state, hybrid gravity stars are more massive than their general relativistic counterparts. Furthermore, two classes of stellar models corresponding to two particular choices of the functional form of the scalar field (constant value, and logarithmic form, respectively) are also investigated. Interestingly enough, in the case of a constant scalar field the equation of state of the matter takes the form of the bag model equation of state describing

  5. Development of Two Isogenic Sweet Corn Hybrids Differing for Glycinebetaine Content 1

    PubMed Central

    Rhodes, David; Rich, Patrick J.; Brunk, Dennis G.; Ju, Grace C.; Rhodes, Judith C.; Pauly, Michael H.; Hansen, Leon A.

    1989-01-01

    A hybrid of sweet corn, Zea mays L. (`1720'; Rogers Brothers Seed Co.), was found to be comprised of glycinebetaine-positive and glycinebetaine-deficient individuals in a 1:1 mixture. This phenomenon was traced to segregation for a single, nuclear, dominant gene determining leaf glycinebetaine content within the female inbred parent of this hybrid. Selection for homozygous recessive (glycinebetaine-deficient) and homozygous dominant (glycinebetaine-positive) genotypes of the female inbred parent enabled production of two isogenic versions of hybrid `1720' differing with respect to a single copy of the dominant allele, by mating these female parent selections with the common homozygous recessive (glycinebetaine-deficient) male parent. These two isogenic hybrids are shown to differ by a factor of 300- to 400-fold in glycinebetaine titer of young expanding leaves of salinized plants, but exhibit no striking differences in the levels of free amino acids or the level of N-methylnicotinic acid (nicotinic acid betaine; trigonelline). The only significant difference between the two hybrids in terms of amino acid composition was found to be in the level of alanine under nonsalinized conditions. The betaine-deficient hybrid exhibited a 14% lower alanine level than the betaine-positive hybrid. Betaine deficiency was not associated with altered stress-induced accumulation of amino acids such as proline, serine, and asparagine plus aspartate, attesting to the high specificity of the genetic difference between these isogenic hybrids with respect to betaine accumulation. This germplasm offers unique opportunities to test whether a single dominant allele determining stress-induced betaine accumulation capacity influences stress resistance in maize. PMID:16667120

  6. Characterization of Hybrid Toluate and Benzoate Dioxygenases

    PubMed Central

    Ge, Yong; Eltis, Lindsay D.

    2003-01-01

    Toluate dioxygenase of Pseudomonas putida mt-2 (TADOmt2) and benzoate dioxygenase of Acinetobacter calcoaceticus ADP1 (BADOADP1) catalyze the 1,2-dihydroxylation of different ranges of benzoates. The catalytic component of these enzymes is an oxygenase consisting of two subunits. To investigate the structural determinants of substrate specificity in these ring-hydroxylating dioxygenases, hybrid oxygenases consisting of the α subunit of one enzyme and the β subunit of the other were prepared, and their respective specificities were compared to those of the parent enzymes. Reconstituted BADOADP1 utilized four of the seven tested benzoates in the following order of apparent specificity: benzoate > 3-methylbenzoate > 3-chlorobenzoate > 2-methylbenzoate. This is a significantly narrower apparent specificity than for TADOmt2 (3-methylbenzoate > benzoate ∼ 3-chlorobenzoate > 4-methylbenzoate ∼ 4-chlorobenzoate ≫ 2-methylbenzoate ∼ 2-chlorobenzoate [Y. Ge, F. H. Vaillancourt, N. Y. Agar, and L. D. Eltis, J. Bacteriol. 184:4096-4103, 2002]). The apparent substrate specificity of the αBβT hybrid oxygenase for these benzoates corresponded to that of BADOADP1, the parent from which the α subunit originated. In contrast, the apparent substrate specificity of the αTβB hybrid oxygenase differed slightly from that of TADOmt2 (3-chlorobenzoate > 3-methylbenzoate > benzoate ∼ 4-methylbenzoate > 4-chlorobenzoate > 2-methylbenzoate > 2-chlorobenzoate). Moreover, the αTβB hybrid catalyzed the 1,6-dihydroxylation of 2-methylbenzoate, not the 1,2-dihydroxylation catalyzed by the TADOmt2 parent. Finally, the turnover of this ortho-substituted benzoate was much better coupled to O2 utilization in the hybrid than in the parent. Overall, these results support the notion that the α subunit harbors the principal determinants of specificity in ring-hydroxylating dioxygenases. However, they also demonstrate that the β subunit contributes significantly to the enzyme

  7. Genomic heterozygosity and hybrid breakdown in cotton (Gossypium): different traits, different effects.

    PubMed

    Dai, Baosheng; Guo, Huanle; Huang, Cong; Zhang, Xianlong; Lin, Zhongxu

    2016-04-12

    Hybrid breakdown has been well documented in various species. Relationships between genomic heterozygosity and traits-fitness have been extensively explored especially in the natural populations. But correlations between genomic heterozygosity and vegetative and reproductive traits in cotton interspecific populations have not been studied. In the current study, two reciprocal F2 populations were developed using Gossypium hirsutum cv. Emian 22 and G. barbadense acc. 3-79 as parents to study hybrid breakdown in cotton. A total of 125 simple sequence repeat (SSR) markers were used to genotype the two F2 interspecific populations. To guarantee mutual independence among the genotyped markers, the 125 SSR markers were checked by the linkage disequilibrium analysis. To our knowledge, this is a novel approach to evaluate the individual genomic heterozygosity. After marker checking, 83 common loci were used to assess the extent of genomic heterozygosity. Hybrid breakdown was found extensively in the two interspecific F2 populations particularly on the reproductive traits because of the infertility and the bare seeds. And then, the relationships between the genomic heterozygosity and the vegetative reproductive traits were investigated. The only relationships between hybrid breakdown and heterozygosity were observed in the (Emian22 × 3-79) F2 population for seed index (SI) and boll number per plant (BN). The maternal cytoplasmic environment may have a significant effect on genomic heterozygosity and on correlations between heterozygosity and reproductive traits. A novel approach was used to evaluate genomic heterozygosity in cotton; and hybrid breakdown was observed in reproductive traits in cotton. These findings may offer new insight into hybrid breakdown in allotetraploid cotton interspecific hybrids, and may be useful for the development of interspecific hybrids for cotton genetic improvement.

  8. An Interspecies Signaling System Mediated by Fusaric Acid Has Parallel Effects on Antifungal Metabolite Production by Pseudomonas protegens Strain Pf-5 and Antibiosis of Fusarium spp.

    PubMed

    Quecine, Maria Carolina; Kidarsa, Teresa A; Goebel, Neal C; Shaffer, Brenda T; Henkels, Marcella D; Zabriskie, T Mark; Loper, Joyce E

    2015-12-11

    Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogens Fusarium verticillioides and Fusarium oxysporum f. sp. pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by many Fusarium species, including F. verticillioides, inhibited the production of DAPG by Pseudomonas spp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis of F. verticillioides by Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressed F. verticillioides due to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression of Fusarium spp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. Neo-sex chromosome inheritance across species in Silene hybrids.

    PubMed

    Weingartner, L A; Delph, L F

    2014-07-01

    Neo-sex chromosomes, which form through the major restructuring of ancestral sex chromosome systems, have evolved in various taxa. Such restructuring often consists of the fusion of an autosome to an existing sex chromosome, resulting in novel sex chromosome formations (e.g. X1X2Y or XY1Y2.). Comparative studies are often made between restructured sex chromosome systems of closely related species, and here we evaluate the consequences of variable sex chromosome systems to hybrids. If neo-sex chromosomes are improperly inherited across species, this could lead to aberrant development and reproductive isolation. In this study, we examine the fate of neo-sex chromosomes in hybrids of the flowering plants Silene diclinis and Silene latifolia. Silene diclinis has a neo-sex chromosome system (XY1Y2) that is thought to have evolved from an ancestral XY system that is still present in S. latifolia. These species do not hybridize naturally, and improper sex chromosome inheritance could contribute to reproductive isolation. We investigated whether this major restructuring of sex chromosomes prevents their proper inheritance in a variety of hybrid crosses, including some F2 - and later-generation hybrids, with sex chromosome-linked, species-specific, polymorphic markers and chromosome squashes. We discovered that despite the differences in sex chromosomes that exist between these two species, proper segregation had occurred in hybrids that made it to flowering, including later-generation hybrids, indicating that neo-sex chromosome formation alone does not result in complete reproductive isolation between these two species. Additionally, hybrids with aberrant sex expression (e.g. neuter, hermaphrodite) also inherited the restructured sex chromosomes properly, highlighting that issues with sexual development in hybrids can be caused by intrinsic genetic incompatibility rather than improper sex chromosome inheritance. © 2014 The Authors. Journal of Evolutionary Biology © 2014

  10. Interspecies Somatic Cell Nuclear Transfer: Advancements and Problems

    PubMed Central

    Lagutina, Irina; Fulka, Helena; Lazzari, Giovanna

    2013-01-01

    Abstract Embryologists working with livestock species were the pioneers in the field of reprogramming by somatic cell nuclear transfer (SCNT). Without the “Dolly experiment,” the field of cellular reprogramming would have been slow and induced plutipotent cells (iPSCs) would not have been conceived. The major drive of the work in mammalian cloning was the interest of the breeding industry to propagate superior genotypes. Soon it was realized that the properties of oocytes could be used also to clone endangered mammalian species or to reprogram the genomes of unrelated species through what is known as interspecies (i) SCNT, using easily available oocytes of livestock species. iSCNT for cloning animals works only for species that can interbreed, and experiments with taxonomically distant species have not been successful in obtaining live births or deriving embryonic stem cell (ESC) lines to be used for regenerative medicine. There are controversial reports in the literature, but in most cases these experiments have underlined some of the cellular and molecular mechanisms that are incomplete during cell nucleus reprogramming, including the failure to organize nucleoli, silence somatic cell genes, activate the embryonic genome, and resume mitochondrial replication and function, thus indicating nucleus–cytoplasmic incompatibility. PMID:24033141

  11. Analysis of nuclear export using photoactivatable GFP fusion proteins and interspecies heterokaryons.

    PubMed

    Nakrieko, Kerry-Ann; Ivanova, Iordanka A; Dagnino, Lina

    2010-01-01

    In this chapter, we review protocols for the analysis of nucleocytoplasmic shuttling of transcription factors and nuclear proteins, using two different approaches. The first involves the use of photoactivatable forms of the protein of interest by fusion to photoactivatable green fluorescent protein to follow its movement out of the nucleus by live-cell confocal microscopy. This methodology allows for the kinetic characterization of protein movements as well as measurement of steady-state levels. In a second procedure to assess the ability of a nuclear protein to move into and out of the nucleus, we describe the use of interspecies heterokaryon assays, which provide a measurement of steady-state distribution. These technologies are directly applicable to the analysis of nucleocytoplasmic movements not only of transcription factors, but also other nuclear proteins.

  12. Contribution of extracellular ATP on the cell-surface F1F0-ATP synthase-mediated intracellular triacylglycerol accumulation.

    PubMed

    Kita, Toshiyuki; Arakaki, Naokatu

    2015-01-01

    Cell-surface F1F0-ATP synthase was involved in the cell signaling mediating various biological functions. Recently, we found that cell-surface F1F0-ATP synthase plays a role on intracellular triacylglycerol accumulation in adipocytes, and yet, the underlying mechanisms remained largely unknown. In this study, we investigated the role of extracellular ATP on the intracellular triacylglycerol accumulation. We demonstrated that significant amounts of ATP were produced extracellularly by cultured 3T3-L1 adipocytes and that the antibodies against α and β subunits of F1F0-ATP synthase inhibited the extracellular ATP production. Piceatannol, a F1F0-ATP synthase inhibitor, and apyrase, an enzyme which degrades extracellular ATP, suppressed triacylglycerol accumulation. The selective P2Y1 receptor antagonist MRS2500 significantly inhibited triacylglycerol accumulation, whereas the selective P2X receptor antagonist NF279 has less effect. The present results indicate that cell-surface F1F0-ATP synthase on adipocytes is functional in extracellular ATP production and that the extracellular ATP produced contributes, at least in part, to the cell-surface F1F0-ATP synthase-mediated intracellular triacylglycerol accumulation in adipocytes through P2Y1 receptor.

  13. Chaperones of F[subscript 1]-ATPase

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

    Ludlam, Anthony; Brunzelle, Joseph; Pribyl, Thomas

    2009-09-25

    Mitochondrial F{sub 1}-ATPase contains a hexamer of alternating {alpha} and {beta} subunits. The assembly of this structure requires two specialized chaperones, Atp11p and Atp12p, that bind transiently to {beta} and {alpha}. In the absence of Atp11p and Atp12p, the hexamer is not formed, and {alpha} and {beta} precipitate as large insoluble aggregates. An early model for the mechanism of chaperone-mediated F{sub 1} assembly (Wang, Z. G., Sheluho, D., Gatti, D. L., and Ackerman, S. H. (2000) EMBO J. 19, 1486--1493) hypothesized that the chaperones themselves look very much like the {alpha} and {beta} subunits, and proposed an exchange of Atp11pmore » for {alpha} and of Atp12p for {beta}; the driving force for the exchange was expected to be a higher affinity of {alpha} and {beta} for each other than for the respective chaperone partners. One important feature of this model was the prediction that as long as Atp11p is bound to {beta} and Atp12p is bound to {alpha}, the two F{sub 1} subunits cannot interact at either the catalytic site or the noncatalytic site interface. Here we present the structures of Atp11p from Candida glabrata and Atp12p from Paracoccus denitrificans, and we show that some features of the Wang model are correct, namely that binding of the chaperones to {alpha} and {beta} prevents further interactions between these F1 subunits. However, Atp11p and Atp12p do not resemble {alpha} or {beta}, and it is instead the F{sub 1} {gamma} subunit that initiates the release of the chaperones from {alpha} and {beta} and their further assembly into the mature complex.« less

  14. Reproductive isolation and the expansion of an invasive hybrid swarm

    USGS Publications Warehouse

    Blum, Michael J.; Walters, David M.; Burkhead, Noel M.; Freeman, Byron J.; Porter, Brady A.

    2010-01-01

    Biological invasions involving hybridization proceed according to prezygotic and postzygotic reproductive isolating mechanisms. Yet few comparisons of reproductive isolation have been carried out to understand how different mechanisms prevent or promote invasions involving hybridization. Here we present a study of prezygotic and postzygotic isolation between non-native red shiner (Cyprinella lutrensis) and native blacktail shiner (C. venusta stigmatura) from the Coosa River basin (USA) to better understand the formation and expansion of invasive hybrid swarms. We conducted spawning trials to measure mating preferences and raised broods from crosses to assay hybrid viability through early juvenile development. Females of both species were more responsive to conspecific mates, although blacktail shiner females responded more often to heterospecific mates than did red shiner females. Fecundity of red shiner females was also higher than blacktail shiner females. Heterospecific crosses resulted in lower fertilization and egg hatching rates, but we found no other evidence of inviability. Rather, we found comparatively low larval mortality of F1 hybrids, which is suggestive of heterosis. These findings support prior inferences of assortative mating from genetic descriptions of hybridization, and that the invasion in the Coosa River is likely proceeding due to interspecific competition and intrinsic hybrid viability.

  15. QCD sum-rules analysis of vector (1-) heavy quarkonium meson-hybrid mixing

    NASA Astrophysics Data System (ADS)

    Palameta, A.; Ho, J.; Harnett, D.; Steele, T. G.

    2018-02-01

    We use QCD Laplace sum rules to study meson-hybrid mixing in vector (1-) heavy quarkonium. We compute the QCD cross-correlator between a heavy meson current and a heavy hybrid current within the operator product expansion. In addition to leading-order perturbation theory, we include four- and six-dimensional gluon condensate contributions as well as a six-dimensional quark condensate contribution. We construct several single and multiresonance models that take known hadron masses as inputs. We investigate which resonances couple to both currents and so exhibit meson-hybrid mixing. Compared to single resonance models that include only the ground state, we find that models that also include excited states lead to significantly improved agreement between QCD and experiment. In the charmonium sector, we find that meson-hybrid mixing is consistent with a two-resonance model consisting of the J /ψ and a 4.3 GeV resonance. In the bottomonium sector, we find evidence for meson-hybrid mixing in the ϒ (1 S ) , ϒ (2 S ), ϒ (3 S ), and ϒ (4 S ).

  16. 17 CFR 270.18f-1 - Exemption from certain requirements of section 18(f)(1) (of the Act) for registered open-end...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... requirements of section 18(f)(1) (of the Act) for registered open-end investment companies which have the right... EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.18f-1 Exemption from certain requirements of section 18(f)(1) (of the Act) for registered open-end investment companies...

  17. Three-dimensional structures of graphene/polyaniline hybrid films constructed by steamed water for high-performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhang, Liling; Huang, Da; Hu, Nantao; Yang, Chao; Li, Ming; Wei, Hao; Yang, Zhi; Su, Yanjie; Zhang, Yafei

    2017-02-01

    A novel three-dimensional (3D) structure of reduced graphene oxide/polyaniline (rGO/PANI) hybrid films has been demonstrated for high-performance supercapacitors. Steamed water in closed vessels with high pressure and moderately high temperature is applied to facilely construct this structure. The as-designed rGO/PANI hybrid films exhibit a highest gravimetric specific capacitance of 1182 F g-1 at 1 A g-1 in the three-electrode test. The assembled symmetric device based on this structure shows both a high capacitance of 808 F g-1 at 1 A g-1 and a high gravimetric energy density (28.06 Wh kg-1 at a power density of 0.25 kW kg-1). Above all, this novel 3D structure constructed by steamed water regulation techniques shows excellent capacitance performance and holds a great promise for high-performance energy storage applications.

  18. Using ToF-SIMS and EIS to evaluate green pretreatment reagent: Corrosion protection of aluminum alloy by silica/zirconium/cerium hybrid coating

    NASA Astrophysics Data System (ADS)

    Chang, Chun-Chao; Wang, Chiung-Chi; Wu, Chia-Wei; Liu, Shou-Ching; Mai, Fu-Der

    2008-12-01

    Increasing environmental concern has led to the restrictive use of chromate conversion coatings to protect Al-alloys from corrosion. Our research is under way to find environmentally compliant substitute coating such as Si/Zr/Ce hybrid coating. The corrosion protection effect of green pretreatment reagent consisted of Si-containing base solution, Ce- and Zr-containing sealing solutions on the corrosion protection of Al-alloys was studied with a 3.5% NaCl aqueous testing solution. The correlation between the corrosion resistance measured by electrochemical impedance spectroscopy (EIS) and surface chemical composition of the hybrid coating measured by time-of-flight secondary ion mass spectroscopy (ToF-SIMS) was studied. The proposed green pretreatment reagent was found improve the corrosion protection of Al-alloys, presumably due to the formation of protective oxide film acting as an oxygen barrier.

  19. 1.31-1.55-µm Hybrid integrated optoelectronic receiver using low-loss quasi-monolithic integration technology

    NASA Astrophysics Data System (ADS)

    Luo, Yang; Huang, Yongqing; Ren, Xiaomin; Duan, Xiaofeng; Wang, Qi

    2014-01-01

    In order to integrate photonic devices with electronic devices to realize the low-loss hybrid integrated devices. A wide spectral hybrid integrated optoelectronic receiver was fabricated by using quasi-monolithic integration technology (QMIT) in this paper. It consisted of a 8.5 GHz InGaAs photodetector and a 1.25 Gbps mature transimpedance pre-amplifier (TIA) complementrary metal oxide semiconductor (CMOS) chip. The Au layer was deposited on a designed Si platform to form planar waveguide electrode which replaced a part of bonding wire, so it reduced the parasitic parameters of the optoelectronic receiver, and then enhanced high-speed response characteristics and the stability of the hybrid integrated receiver. Finally, a 3 Gbps clear open eye diagram of the hybrid integrated optoelectronic receiver was obtained.

  20. Comprehensive mollusk acute toxicity database improves the use of Interspecies Correlation Estimation (ICE) models to predict toxicity of untested freshwater and endangered mussel species

    EPA Science Inventory

    Interspecies correlation estimation (ICE) models extrapolate acute toxicity data from surrogate test species to untested taxa. A suite of ICE models developed from a comprehensive database is available on the US Environmental Protection Agency’s web-based application, Web-I...