7 research outputs found
Pediatric hyperlipidemia
This issue of eMedRef provides information to clinicians on the pathophysiology, diagnosis, and therapeutics of pediatric hyperlipidemia
Gene discovery in EST sequences from the wheat leaf rust fungus Puccinia triticina sexual spores, asexual spores and haustoria, compared to other rust and corn smut fungi
© 2011 Xu et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.DOI: 10.1186/1471-2164-12-161Background.Rust fungi are biotrophic basidiomycete plant pathogens that cause major diseases on plants and trees world-wide, affecting agriculture and forestry. Their biotrophic nature precludes many established molecular genetic manipulations and lines of research. The generation of genomic resources for these microbes is leading to novel insights into biology such as interactions with the hosts and guiding directions for breakthrough research in plant pathology. Results. To support gene discovery and gene model verification in the genome of the wheat leaf rust fungus, Puccinia triticina (Pt), we have generated Expressed Sequence Tags (ESTs) by sampling several life cycle stages. We focused on several spore stages and isolated haustorial structures from infected wheat, generating 17,684 ESTs. We produced sequences from both the sexual (pycniospores, aeciospores and teliospores) and asexual (germinated urediniospores) stages of the life cycle. From pycniospores and aeciospores, produced by infecting the alternate host, meadow rue (Thalictrum speciosissimum), 4,869 and 1,292 reads were generated, respectively. We generated 3,703 ESTs from teliospores produced on the senescent primary wheat host. Finally, we generated 6,817 reads from haustoria isolated from infected wheat as well as 1,003 sequences from germinated urediniospores. Along with 25,558 previously generated ESTs, we compiled a database of 13,328 non-redundant sequences (4,506 singlets and 8,822 contigs). Fungal genes were predicted using the EST version of the self-training GeneMarkS algorithm. To refine the EST database, we compared EST sequences by BLASTN to a set of 454 pyrosequencing-generated contigs and Sanger BAC-end sequences derived both from the Pt genome, and to ESTs and genome reads from wheat. A collection of 6,308 fungal genes was identified and compared to sequences of the cereal rusts, Puccinia graminis f. sp. tritici (Pgt) and stripe rust, P. striiformis f. sp. tritici (Pst), and poplar leaf rust Melampsora species, and the corn smut fungus, Ustilago maydis (Um). While extensive homologies were found, many genes appeared novel and species-specific; over 40% of genes did not match any known sequence in existing databases. Focusing on spore stages, direct comparison to Um identified potential functional homologs, possibly allowing heterologous functional analysis in that model fungus. Many potentially secreted protein genes were identified by similarity searches against genes and proteins of Pgt and Melampsora spp., revealing apparent orthologs. Conclusions. The current set of Pt unigenes contributes to gene discovery in this major cereal pathogen and will be invaluable for gene model verification in the genome sequence
Comparative Analysis Highlights Variable Genome Content of Wheat Rusts and Divergence of the Mating Loci
Three members of the
Puccinia
genus,
Puccinia
triticina
(
Pt
),
P
.
striiformis
f.sp.
tritici
(
Pst
), and
P
.
graminis
f.sp.
tritici
(
Pgt
), cause the most common and often most significant foliar diseases of wheat. While similar in biology and life cycle, each species is uniquely adapted and specialized. The genomes of
Pt
and
Pst
were sequenced and compared to that of
Pgt
to identify common and distinguishing gene content, to determine gene variation among wheat rust pathogens, other rust fungi, and basidiomycetes, and to identify genes of significance for infection.
Pt
had the largest genome of the three, estimated at 135 Mb with expansion due to mobile elements and repeats encompassing 50.9% of contig bases; in comparison, repeats occupy 31.5% for
Pst
and 36.5% for
Pgt
. We find all three genomes are highly heterozygous, with
Pst
[5.97 single nucleotide polymorphisms (SNPs)/kb] nearly twice the level detected in
Pt
(2.57 SNPs/kb) and that previously reported for
Pgt
. Of 1358 predicted effectors in
Pt
, 784 were found expressed across diverse life cycle stages including the sexual stage. Comparison to related fungi highlighted the expansion of gene families involved in transcriptional regulation and nucleotide binding, protein modification, and carbohydrate degradation enzymes. Two allelic homeodomain pairs, HD1 and HD2, were identified in each dikaryotic
Puccinia
species along with three pheromone receptor (
STE3
) mating-type genes, two of which are likely representing allelic specificities. The HD proteins were active in a heterologous
Ustilago maydis
mating assay and host-induced gene silencing (HIGS) of the HD and
STE3
alleles reduced wheat host infection
Observation of WWW Production in pp Collisions at √s = 13 TeV with the ATLAS Detector
This Letter reports the observation of
W
W
W
production and a measurement of its cross section using
139
fb
−
1
of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from
W
W
W
production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive
W
W
W
production cross section is measured to be
820
±
100
(
stat
)
±
80
(
syst
)
fb
, approximately 2.6 standard deviations from the predicted cross section of
511
±
18
fb
calculated at next-to-leading-order QCD and leading-order electroweak accuracy