Suchergebnisse

10 páginas, 2 tablas y 3 figuras. ; Terpenoids are secondary metabolites produced in most plant tissues and are often considered toxic or repellent to plant enemies. Previous work has typically reported on intra-specific variation in terpene profiles, but the effects of plant sex, an important axis of genetic variation, have been less studied for chemical defences in general, and terpenes in particular. In a prior study, we found strong genetic variation (but not sexual dimorphism) in terpene amounts in leaves of the dioecious shrub Baccharis salicifolia. Here we build on these findings and provide a more in-depth analysis of terpene chemistry on these same plants from an experiment consisting of a common garden with male (N = 19) and female (N = 20) genotypes sourced from a single population. Our goal in the present study was to investigate quantitative and qualitative differences in terpene profiles associated with plant sex and genotypic variation. For this, we quantified leaf mono- and sesquiterpene amount, richness, and diversity (quantitative profile), as well as the composition of compounds (qualitative profile). We found no evidence of sexual dimorphism in monoterpene or sesquiterpene profiles. We did, however, find significant genotypic variation in amount, diversity, and composition of monoterpenes, but no effects on sesquiterpenes. These findings indicated that genotypic variation in terpene profiles largely surpassed variation due to sexual dimorphism for the studied population of this species. ; This research was funded by National Science Foundation grants DEB-1354734, DEB-1457029 and DEB-1120794 to KAM. XM was supported by a Spanish National Research Grant (AGL2015-70748-R), a grant from the Regional Government of Galicia (IN607D 2016/001) and the Ramon y Cajal Research Programme (RYC-2013-13230). ; Peer reviewed

To meet the needs of carbon sequestration and production of raw materials from renewable natural resources for the timber market of the European Union, it is necessary to expand forest plantation areas. The efficiency of short rotation forestry depends primarily on the selection of hybrids and clones, suitable for the local environmental conditions. We postulate that ecogenetic response, ecogenetic plasticity and genotypic variation of different hybrids of poplars (Populus L.) depend both on the type of stressors (spring frosts, summer drought, increased UV-B radiation, warm winters) and peculiarities of the cross-bred species as well as on their genetic preadaptations to native environmental conditions of their origin. The aim of the study was to estimate the ecogenetic plasticity, genotypic variation of adaptive traits and adaptability of Populus hybrids under simulated conditions of the expected climate change. The research was performed with the cultivars and experimental clones of three different intraspecific hybrids of poplars (P. nigra L., P. deltoides Bartr. ex Marsh, and P. trichocarpa Torr. & Gray.) and four interspecific hybrids of poplars (P. deltoides L. × P. nigra, P. deltoides × P. trichocarpa, P. maximowiczii A. Henry × P. trichocarpa, and P. balsamifera L. × P. trichocarpa). Simulated spring frosts and summer drought treatments had a substantial impact on growth of trees, but the hybrid and clone effects were also significant and showed that many hybrids and clones in general retain their features/differences under stressful environmental conditions. A strongly expressed hybrid and clone interactions with simulated frost and drought effects (genotype-environment interaction, G × E) showed different ecogenetic response, plasticity and specific ecological preferences of the clones and hybrids. The sensitivity of hybrids to UV-B radiation varied and depended on the origin of their parental trees and this sensitivity partially reflected their susceptibility also to other stressors. Warm winters adversely effected the growth of some hybrids while others - P. nigra × P. nigra and P. trichocarpa × P. trichocarpa, which parents originated from the southern part of their natural distribution range have increased their growth. This treatment also resulted in reduction of the heritability and genotypic variation of growth traits. Keywords: poplars, clones, genotype-environment interaction, genetic variation, heritability.

To meet the needs of carbon sequestration and production of raw materials from renewable natural resources for the timber market of the European Union, it is necessary to expand forest plantation areas. The efficiency of short rotation forestry depends primarily on the selection of hybrids and clones, suitable for the local environmental conditions. We postulate that ecogenetic response, ecogenetic plasticity and genotypic variation of different hybrids of poplars (Populus L.) depend both on the type of stressors (spring frosts, summer drought, increased UV-B radiation, warm winters) and peculiarities of the cross-bred species as well as on their genetic preadaptations to native environmental conditions of their origin. The aim of the study was to estimate the ecogenetic plasticity, genotypic variation of adaptive traits and adaptability of Populus hybrids under simulated conditions of the expected climate change. The research was performed with the cultivars and experimental clones of three different intraspecific hybrids of poplars (P. nigra L., P. deltoides Bartr. ex Marsh, and P. trichocarpa Torr. & Gray.) and four interspecific hybrids of poplars (P. deltoides L. × P. nigra, P. deltoides × P. trichocarpa, P. maximowiczii A. Henry × P. trichocarpa, and P. balsamifera L. × P. trichocarpa). Simulated spring frosts and summer drought treatments had a substantial impact on growth of trees, but the hybrid and clone effects were also significant and showed that many hybrids and clones in general retain their features/differences under stressful environmental conditions. A strongly expressed hybrid and clone interactions with simulated frost and drought effects (genotype-environment interaction, G × E) showed different ecogenetic response, plasticity and specific ecological preferences of the clones and hybrids. The sensitivity of hybrids to UV-B radiation varied and depended on the origin of their parental trees and this sensitivity partially reflected their susceptibility also to other stressors. Warm winters adversely effected the growth of some hybrids while others - P. nigra × P. nigra and P. trichocarpa × P. trichocarpa, which parents originated from the southern part of their natural distribution range have increased their growth. This treatment also resulted in reduction of the heritability and genotypic variation of growth traits. Keywords: poplars, clones, genotype-environment interaction, genetic variation, heritability.

Funding: Research Executive Agency to SH (https://erc.europa.eu/); European Union's Horizon 2020 research andinnovation program under the Marie Sklodowska-Curie grant agreement No"GA655978"; University of Tübingen (EKUT), Ministry for Science and Art Baden-Württemberg via the RiSC, infrastructural funding from the Deutsche Forschungsgemeinschaft (DFG), Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections (SH); Chief Scientists Office (Reference: SIRN10) (MTGH). ; Gene tandem amplifications are thought to drive bacterial evolution, but they are transient in the absence of selection, making their investigation challenging. Here, we analyze genomic sequences of Staphylococcus aureus USA300 isolates from the same geographical area to identify variations in gene copy number, which we confirm by long-read sequencing. We find several hotspots of variation, including the csa1 cluster encoding lipoproteins known to be immunogenic. We also show that the csa1 locus expands and contracts during bacterial growth in vitro and during systemic infection of mice, and recombination creates rapid heterogeneity in initially clonal cultures. Furthermore, csa1 copy number variants differ in their immunostimulatory capacity, revealing a mechanism by which gene copy number variation can modulate the host immune response. ; Publisher PDF ; Peer reviewed

Kappa casein (ĸ-cn) gene as one of the four casein genes commonly has two variant alleles. B allele is positively correlated with milk proteins, so potentially be used as MAS to improve milk protein content. This study aimed to identify genetic variation of the ĸ-casein gene in Holstein-Friesian (HF) from several dairy regions in West Java. Blood samples were taken through jugular vein of lactating heifers and cows, from intensive managements under the Local Government Dairy Breeding Station - Cikole (BBPT Cikole-SP) (82 hds), Embryo Transfer Station (BET) (50 hds), and Eco Farm of Animal Science Faculty of Bogor Agricultural University (EcoFarm) (20 hds); as well as from semi-intensive managements of small dairy farmers under the supervision of the North Lembang Cooperative Unit (KPSBU Lembang) in two villages of Cilumber (98 hds) and Pasar Kemis (92 hds). Blood samples were also taken via cocsigalis vein of AI (active and non active) HF bulls at the two National AI Stations in Lembang (25 hds) and Singosari (32 hds). Identification of genetic variation was by applying PCR-RFLP method. Three genotypes were identified, namely AA, AB, and BB, resulting two alleles of A and B. Results entirely showed that the frequencies of the BB HF female were very low, with the range of 0%-6% (vs AA genotype= 10%-54% and AB genotype= 46%-85%), despite of the relatively high frequency of the B allele over the A allele (23%-48% vs. 52%-77%). The low frequency of the observed BB females might be due to the limited AI active BB bulls used for services by the two national AI stations (0%-4%).

8 páginas, 1 figura, 4 tablas. ; A collection of 121 common bean (Phaseolus vulgaris L.) landraces from Spain and Portugal (Iberian Peninsula) was evaluated in six environments (three locations and 2 years). Significant differences among landraces were found for period of flowering, pod maturity and pod morphology (weight, length, width/thickness and curvature). Wide variation among landraces was revealed by the range of variation observed. Environmental effects were not significant although year × location and landrace × year × location interactions were significant for all traits studied except for pod curvature. Poor consistent expression across the different environments for most of the traits studied was expressed by the low values of constancy (C) with the exception of width/thickness indicating that pod shape (round or flat) was expressed regularly across different environments. Principal component analysis enhanced differences among environments affecting the performance of the bean landraces evaluated. Analysis by environment showed that 51 landraces were adapted to specific environments and only four of them had broad geographical adaptability with similar performance under different conditions. These results could be a starting point for selection of new inbred lines adapted to distinct environments with potential for the improvement of current snap bean cultivars. ; This research was supported by the Project AGF-93-0756- C02-01 from the Government of Spain. The authors thank two grants to P. A. Casquero from the Governments of Spain and Galicia (Spain) and a grant from the Spanish Government to A. M. González ; Peer reviewed

Bitter substances are identified by protein receptors located on surface of taste cell membranes. Mutational polymorphism of the bitter taste receptor (TAS2R38) is a significant determinant in phenylthiocarbamide (PTC) threshold perception. This research's objectives were to find TAS2R38 polymorphisms in Iraqi people and investigate any correlations between genotype and the PTC taste sensitivity. Bitterness sensitivity was determined by assessing the capacity to differentiate and the responsiveness to a representative strip of PTC. Cheek cells samples were collected for DNA extraction, PCR amplification and genotyping. PCR was performed to amplify the short region of the TAS2R38 gene containing the initial polymorphisms of interest (145G > C, rs713598). Amplified samples were digested by the restriction enzyme (HaeIII) to study the genetic variations in TAS2R38 which is involved in PTC bitter sensitivity.
This particular study included a total of 32 different cohorts. The phenotypic frequency of PTC strong-tasters and non-tasters was identical at 34.375% which was a greater value than the frequency of weak-tasters (31.25%). While genotypic data analysis showed that weak-tasters had a genotypic frequency of 45.16% which was higher than the genotypic frequencies of strong-taters (22.58%) and non-tasters (32.26%) respectively. In addition to this, 87.1% of the projected phenotypic and genotypic frequencies were in agreement with one another.
Even though more detailed statistical analysis with a bigger group is needed. The results of this study suggest that allelic variation in the single locus TAS2R38 rs713598 works as a crucial genetic marker for bitterness sensitivity and has vital roles in the bitter tasting ability among Iraqi population.