Since emerging in Brazil in 1985, wheat blast has spread throughout South America and recently appeared in Bangladesh and Zambia. Here we show that two wheat resistance genes, Rwt3 and Rwt4, acting as host-specificity barriers against non-Triticum blast pathotypes encode a nucleotide-binding leucine-rich repeat immune receptor and a tandem kinase, respectively. Molecular isolation of these genes will enable study of the molecular interaction between pathogen effector and host resistance genes.
Abstract Phylogenomic analysis of large genome-wide sequence data sets can resolve phylogenetic tree topologies for large species groups, help test the accuracy of and improve resolution for earlier multilocus studies and reveal the level of agreement or concordance within partitions of the genome for various tree topologies. Here we used a target-capture approach to sequence 1,088 single-copy exons for more than 200 labrid fishes together with more than 100 outgroup taxa to generate a new data-rich phylogeny for the family Labridae. Our time-calibrated phylogenetic analysis of exon-capture data pushes the root node age of the family Labridae back into the Cretaceous to about 79 Ma years ago. The monotypic Centrogenys vaigiensis, and the order Uranoscopiformes (stargazers) are identified as the sister lineages of Labridae. The phylogenetic relationships among major labrid subfamilies and within these clades were largely congruent with prior analyses of select mitochondrial and nuclear datasets. However, the position of the tribe Cirrhilabrini (fairy and flame wrasses) showed discordance, resolving either as the sister to a crown julidine clade or alternatively sister to a group formed by the labrines, cheilines and scarines. Exploration of this pattern using multiple approaches leads to slightly higher support for this latter hypothesis, highlighting the importance of genome-level data sets for resolving short internodes at key phylogenetic positions in large, economically important groups of coral reef fishes. More broadly, we demonstrate how accounting for sources of biological variability from incomplete lineage sorting and exploring systematic error at conflicting nodes can aid in evaluating alternative phylogenetic hypotheses.
Species- and genetic diversity can change in parallel, resulting in a species-genetic diversity correlation (SGDC) and raising the question if the same drivers influence both biological levels of diversity. The SGDC can be either positive or negative, depending on whether the species diversity and the genetic diversity of the measured species respond in the same or opposite way to drivers. Using a traditional species diversity approach together with ultra-conserved elements and high throughput sequencing, we evaluated the SGDCs in benthic macrofauna communities in the Baltic Sea, a geologically young brackish water sea characterised by its steep salinity gradient and low species richness. Assessing SGDCs from six focal marine invertebrate species from different taxonomic groups and with differing life histories and ecological functions on both a spatial and temporal scale gives a more comprehensive insight into the community dynamics of this young ecosystem and the extrinsic factors that might drive the SGDCs.
This short video illustrates, on a molecular level, how myBaits hybridization works. Increase samples per sequencing run and reduce analysis effort.
North American minnows of the Shiner Clade, within the family Leuciscidae, represent one of the most taxonomically complex clades of the order Cypriniformes due to the large number of taxa coupled with conserved morphologies. Species within this clade were moved between genera and subgenera until the community decided to lump many of the unclassified taxa with similar morphologies into one genus, Notropis , which has held up to 325 species. Despite phylogentic studies that began to re-elevate some genera merged into Notropis , such as Cyprinella , Luxilus , Lythrurus , and Pteronotropis , the large genus Notropis remained as a taxonomic repository for many shiners of uncertain placement. Recent molecular advances in sequencing technologies have provided the opportunity to re-examine the Shiner Clade using phylogenomic markers. Using a fish probe kit, we sequenced 90 specimens in 87 species representing 16 genera included in the Shiner Clade, with a resulting dataset of 1,004 loci and 286,455 base pairs. Despite the large dataset, only 32,349 bp (11.29%) were phylogenetically informative. In our maximum likelihood tree, 78% of nodes are 100% bootstrap supported demonstrating the utility of the phylogenomic markers at lower taxonomic levels. Unsurprisingly, species within Notropis as well as Hudsonius , Luxilus , and Alburnops are not resolved as monophyletic groups. Cyprinella is monophyletic if Cyprinella callistia is excluded, and Pteronotropis is monophyletic if it includes Hudsonius cummingsae . Taxonomic changes we propose are: restriction of species included in Alburnops and Notropis , elevation of the subgenus Hydrophlox , expansion of species included in Miniellus , movement of Hudsonius cummingsae to Pteronotropis , and resurrection of the genera Coccotis and Paranotropis . We additionally had two specimens of three species, Notropis atherinoides, Ericymba amplamala , and Pimephales vigilax and found signficant differences between the localities (1,086, 1,424, and 845 nucleotides respectively).
Abstract For 175 years, an unremarkable bass, the Grape-eye Seabass (Hemilutjanus macrophthalmos), has been known from coastal waters in the Eastern Pacific. To date, its phylogenetic placement and classification have been ignored. A preliminary osteological examination of Hemilutjanus hinted that it may have affinities with the Acropomatiformes. To test this hypothesis, we conducted a phylogenetic analysis using UCE and Sanger sequence data to study the placement of Hemilutjanus and the limits and relationships of the Acropomatiformes. We show that Hemilutjanus is a malakichthyid, and our results corroborate earlier studies that have resolved a polyphyletic Polyprionidae; accordingly, we describe Stereolepididae, new family, for Stereolepis. With these revisions, the Acropomatiformes is now composed of the: Acropomatidae; Banjosidae; Bathyclupeidae; Champsodontidae; Creediidae; Dinolestidae; Epigonidae; Glaucosomatidae; Hemerocoetidae; Howellidae; Lateolabracidae; Malakichthyidae; Ostracoberycidae; Pempheridae; Pentacerotidae; Polyprionidae; Scombropidae; Stereolepididae, new family; Symphysanodontidae; Synagropidae; and Schuettea. Finally, using our new hypothesis, we demonstrate that acropomatiforms repeatedly evolved bioluminescence and transitioned between shallow waters and the deep sea.
Ann Arbor, MI 48103
(d/b/a Daicel Arbor Biosciences)
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