Population Structure and Genetic Diversity of Two-Rowed Barley Accessions from Kazakhstan Based on SNP Genotyping Data

The genetic relationship and population structure of two-rowed barley accessions from Kazakhstan were assessed using single-nucleotide polymorphism (SNP) markers. Two different approaches were employed in the analysis: (1) the accessions from Kazakhstan were compared with barley samples from six different regions around the world using 1955 polymorphic SNPs, and (2) 94 accessions collected from six breeding programs from Kazakhstan were studied using 5636 polymorphic SNPs using a 9K Illumina Infinium assay. In the first approach, the neighbor-joining tree showed that the majority of the accessions from Kazakhstan were grouped in a separate subcluster with a common ancestral node; there was a sister subcluster that comprised mainly barley samples that originated in Europe. The Pearson’s correlation analysis suggested that Kazakh accessions were genetically close to samples from Africa and Europe. In the second approach, the application of the STRUCTURE package using 5636 polymorphic SNPs suggested that Kazakh barley samples consisted of five subclusters in three major clusters. The principal coordinate analysis plot showed that, among six breeding origins in Kazakhstan, the Krasnovodopad (KV) and Karaganda (KA) samples were the most distant groups. The assessment of the pedigrees in the KV and KA samples showed that the hybridization schemes in these breeding stations heavily used accessions from Ethiopia and Ukraine, respectively. The comparative analysis of the KV and KA samples allowed us to identify 214 SNPs with opposite allele frequencies that were tightly linked to 60 genes/gene blocks associated with plant adaptation traits, such as the heading date and plant height. The identified SNP markers can be efficiently used in studies of barley adaptation and deployed in breeding projects to develop new competitive cultivars.

Phylogenetic Methods Inconsistently Predict the Direction of HIV Transmission Among Heterosexual Pairs in the HPTN 052 Cohort

BackgroundWe evaluated use of phylogenetic methods to predict the direction of human immunodeficiency virus (HIV) transmission.MethodsFor 33 pairs of HIV-infected patients (hereafter, “index patients”) and their partners who acquired genetically linked HIV infection during the study, samples were collected from partners and index patients close to the time when the partner seroconverted (hereafter, “SC samples”); for 31 pairs, samples collected from the index patient at an earlier time point (hereafter, “early index samples”) were also available. Phylogenies were inferred using env next-generation sequences (1 tree per pair/subtype). The direction of transmission (DoT) predicted from each tree was classified as correct or incorrect on the basis of which sequences (those from the index patient or the partner) were closest to the root. DoT was also assessed using maximum parsimony to infer ancestral node states for 100 bootstrap trees.ResultsDoT was predicted correctly for both single-pair and subtype-specific trees in 22 pairs (67%) by using SC samples and in 23 pairs (74%) by using early index samples. DoT was predicted incorrectly for 4 pairs (15%) by using SC or early index samples. In the bootstrap analysis, DoT was predicted correctly for 18 pairs (55%) by using SC samples and for 24 pairs (73%) by using early index samples. DoT was predicted incorrectly for 7 pairs (21%) by using SC samples and for 4 pairs (13%) by using early index samples.ConclusionsPhylogenetic methods based solely on the tree topology of HIV env sequences, particularly without consideration of phylogenetic uncertainty, may be insufficient for determining DoT.

NETWORK ANALYSIS ON THE IN SILICO ASSIGNED Y CHROMOSOME HAPLOGROUPS IN WESTERN BALKAN POPULATIONS

The region of Western Balkans has been inhabited since the Paleolithic era and was the route of the spread of farming from the Middle East to Europe during the Neolithic era. In the present study, Y-STR data from European populations have been used to construct median-joining networks. The study was performed using Whit Athey’s Haplogroup Predictor, Y Utility and Network 4 software packages to predict Y haplogroups, construct networks, perform clustering of closely related Y chromosomes and calculate time estimates between individual nodes. The results of the study imply that geographically close populations cluster together at both Balkan and European levels. It was observed that an elevated number of study populations and individual haplogroups increases the possibility that individuals of different ethnic background cluster within the same or neighboring clades of network. Subsequent time estimates, performed based on the mutation frequency between the ancestral node and its descendant nodes, revealed that I2a haplogroup within the Western Balkan region has the most compact clustering (age, estimated at 3109 years), followed by Hg E1b1b which has the second most compact clustering (4896 years). The obtained results are nonetheless in accordance with previously published research investigating the frequency of Y haplogroups based on Y-SNP variant frequencies, indicating that Western Balkan countries are mainly represented by I2a subclade (average for six countries 32.3%), followed by E1b1b and R1a (average for six countries of 21.5% and 17%, respectively).

Estudio computacional de las relaciones evolutivas de los receptores ionotrópicos NMDA, AMPA y kainato en cuatro especies de primates

<p><strong></strong><strong>Objective.</strong> To identify the influence of changes on the secondary structure and evolutionary relationship of NMDA, AMPA and kainate receptors in <em>Homo sapiens</em>,<em> Pan troglodytes</em>, <em>Pongo pygmaeus</em> and <em>Macaca mulatta</em>. <strong>Materials and methods.</strong> We identified 91 sequences for NMDA, AMPA and kainate receptors and analyzed with software for predicting secondary structure, phosphorylation sites, multiple alignments, selection of protein evolution models and phylogenetic prediction. <strong>Results.</strong> We found that subunits GLUR5, NR2A, NR2C and NR3A showed structural changes in the C-terminal region and formation or loss of phosphorylation sites in this zone. Additionally the phylogenetic prediction suggests that the NMDA NR2 subunits are the closest to the ancestral node that gives rise to the other subunits. <strong>Conclusions.</strong> Changes in structure and phosphorylation sites in GLUR5, NR2A, NR2C and NR3A subunits suggest variations in the interaction of the C-terminal region with kinase proteins and with proteins with PDZ domains, which could affect the trafficking and anchoring of the subunits. On the other hand, the phylogenetic prediction suggests that the changes that occurred in the NR2 subunits gave rise to the other subunits of glutamate ionotropic receptors, primarily because the NMDA and particularly the NR2D subunits are the most closely related to the ancestral node that possibly gave rise to the iGluRs.</p> <p><strong>Key words: </strong>glutamate ionotropic receptors, iGluRs, NMDA, NR1, NR2A, NR2C, NR3A, AMPA, GluR5.</p><br />