The distribution of DNA sequences homologous with three mer genes was determined in unselected and mercury-resistant water and sediment isolates. The maximum proportions of unselected bacterial isolates containing DNA hybridizing with the 358merA, 358merB, and 501merR probes, derived from gram-negative organisms, were 93.8, 21, and 100%, respectively. Up to 53.3% of mercury chloride-resistant isolates and 54% of methylmercury hydroxide-resistant isolates did not contain DNA homologous with 358merA or 358merB, respectively. Hybridizations performed at high and low stringencies demonstrated that divergence of the merA gene accounted for many of the mercury-resistant but probe-negative isolates. Sixteen mercury-resistant Bacillus spp. isolated from the least contaminated site all contained DNA homologous with 258merA, originally from a gram-positive organism, but only four hybridized weakly with 358merA. The results demonstrate the wide distribution of mercury resistance genes but, because of the diversity of genetic determinants, highlight the importance of using multiple detection techniques and gene probes derived from a variety of origins for such studies.
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http://dx.doi.org/10.1128/aem.57.6.1581-1589.1991 | DOI Listing |
PLoS One
January 2025
Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Italy.
Nematodes are abundant and ubiquitous animals which are poorly known at intraspecific level. This work represents the first attempt to fill the gap on basic knowledge of genetic variability and differentiation in Protostrongylus oryctolagi, a nematode parasite of lagomorphs. 68 cox1 sequences were obtained from brown hares collected in five locations in Northern and Central Italy, highlighting the presence of a high amount of genetic variation inside this species.
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January 2025
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Ciudad de México, México.
Tequila bats (genus Leptonycteris) have gained attention for their critical role in pollinating different plant species, especially Agave spp. and columnar cacti. Leptonycteris nivalis is the largest nectar-feeding bat in the Americas, and the females exhibit migratory behavior during the breeding season.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA.
Background: Biorepositories play an integral role in the advancement of our understanding of neurodegenerative diseases and improving human health outcomes. Research efforts are accelerated when access to high-quality clinical specimens is made available from a large, diverse participant group. Indiana University is home to three important neurodegenerative disease-focused biorepositories including the NIA-funded National Centralized Repository for Alzheimer's Disease and Related Dementias (NCRAD), the NINDS-funded Biospecimen Exchange for Neurological Disorders (BioSEND), and the Michael J.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA.
Background: The burden of Alzheimer's disease and related dementias is growing fast in Africa. The Recruitment and Retention for Alzheimer's Disease Diversity Genetic Cohorts in the Alzheimer's Disease Sequencing Project (READD-ADSP) has commenced recruitment of 5000 African participants (AD and cognitively unimpaired individuals) to generate genomic and biomarker data to better characterize AD genetic architecture in Africa. Participating countries, part of the African Dementia Consortium (AfDC) include Nigeria, Ghana, Benin, Cameroon, Uganda, Kenya, Ethiopia, Tanzania, and Mozambique.
View Article and Find Full Text PDFBackground: Aggregated TDP-43 is found as the main component of pathological inclusions in amyotrophic lateral sclerosis (ALS), limbic-predominant age-related TDP-43 encephalopathy (LATE), in 50% of patients with frontotemporal dementia (FTD), and is present as co-pathology in other neurodegenerative diseases, including Alzheimer's disease (AD). Biofluid or imaging biomarkers of TDP-43 pathology are currently unavailable. Direct detection of TDP-43 aggregates holds promise for unraveling the pathobiology of disease and for enabling precision medicine approach via improved diagnosis, patient stratification and assessment of therapeutic efficacy in clinical trials in AD and related diseases.
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