Background: The genomic fractions of purine (RR) and alternating pyrimidine/purine (YR) stretches of 10 base pairs or more, have been linked to genomic AT content, the formation of different DNA helices, strand-biased gene distribution, DNA structure, and more. Although some of these factors are a consequence of the chemical properties of purines and pyrimidines, a thorough statistical examination of the distributions of YR/RR stretches in sequenced prokaryotic chromosomes has to the best of our knowledge, not been undertaken. The aim of this study is to expand upon previous research by using regression analysis to investigate how AT content, habitat, growth temperature, pathogenicity, phyla, oxygen requirement and halotolerance correlated with the distribution of RR and YR stretches in prokaryotes.
Results: Our results indicate that RR and YR-stretches are differently distributed in prokaryotic phyla. RR stretches are overrepresented in all phyla except for the Actinobacteria and beta-Proteobacteria. In contrast, YR tracts are underrepresented in all phyla except for the beta-Proteobacterial group. YR-stretches are associated with phylum, pathogenicity and habitat, whilst RR-tracts are associated with phylum, AT content, oxygen requirement, growth temperature and halotolerance. All associations described were statistically significant with p < 0.001.
Conclusion: Analysis of chromosomal distributions of RR/YR sequences in prokaryotes reveals a set of associations with environmental factors not observed with mono- and oligonucleotide frequencies. This implies that important information can be found in the distribution of RR/YR stretches that is more difficult to obtain from genomic mono- and oligonucleotide frequencies. The association between pathogenicity and fractions of YR stretches is assumed to be linked to recombination and horizontal transfer.
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http://dx.doi.org/10.1186/1471-2164-10-346 | DOI Listing |
Nat Commun
December 2024
School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China.
The discovery of ferromagnetism in van der Waals (vdW) materials has enriched the understanding of two-dimensional (2D) magnetic orders and opened new avenues for fundamental physics research and next generation spintronics. However, achieving ferromagnetic order at room temperature, along with strong perpendicular magnetic anisotropy, remains a significant challenge. In this work, we report wafer-scale growth of vdW ferromagnet FeGaTe using molecular beam epitaxy.
View Article and Find Full Text PDFNat Commun
December 2024
Engineering Science and Mechanics, Penn State University, University Park, PA, USA.
Incipient ferroelectricity bridges traditional dielectrics and true ferroelectrics, enabling advanced electronic and memory devices. Firstly, we report incipient ferroelectricity in freestanding SrTiO nanomembranes integrated with monolayer MoS to create multifunctional devices, demonstrating stable ferroelectric order at low temperatures for cryogenic memory devices. Our observation includes ultra-fast polarization switching (~10 ns), low switching voltage (<6 V), over 10 years of nonvolatile retention, 100,000 endurance cycles, and 32 conductance states (5-bit memory) in SrTiO-gated MoS transistors at 15 K and up to 100 K.
View Article and Find Full Text PDFEcol Lett
January 2025
Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews, UK.
Given that reproductive physiology is highly sensitive to thermal stress, there is increasing concern about the effects of climate change on animal fertility. Even a slight reduction in fertility can have consequences for population growth and survival, so it is critical to better understand and predict the potential effects of climate change on reproductive traits. We synthesised 1894 effect sizes across 276 studies on 241 species to examine thermal effects on fertility in aquatic animals.
View Article and Find Full Text PDFEcol Lett
January 2025
Department of Entomology and Nematology, University of California, Davis, Davis, California, USA.
Plant-microbe associations are ubiquitous, but parsing contributions of dispersal, host filtering, competition and temperature on microbial community composition is challenging. Floral nectar-inhabiting microbes, which can influence flowering plant health and pollination, offer a tractable system to disentangle community assembly processes. We inoculated a synthetic community of yeasts and bacteria into nectars of 31 plant species while excluding pollinators.
View Article and Find Full Text PDFOpen Vet J
November 2024
Department of Nursing, Technical Institute of Suwaria, Middle Technical University, Baghdad, Iraq.
Background: Ozone (O) is a promising alternative antibacterial agent that has recently been used in meat processing. The understanding of the appropriate functional settings of O for addressing food safety problems is still insufficient.
Aim: The aim of this study was, therefore, to investigate the effects of exposure to O on the bacteriological quality of retail meat inoculated with at refrigeration temperatures.
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