Embryo DNA, isolated from ungerminated seeds of Lupinus angustifolius L., contains an exceptionally high amount of guanine-cytosine-rich satellite DNA. The thermal denaturation curve of total embryo DNA is biphasic with an inflexion point at 62% denaturation, indicating the presence of satellite DNA. The satellite fraction could be separated from the mainband DNA by three successive preparative CsCl-gradient centrifugations. The densities of the DNA fractions are 1.7045 g cm(-3) and 1.6925 g cm(-3), respectively. The percentages of guanine-cytosine calculated from these densities are comparable to the percentages of GC calculated from the melting temperatures. Finally, ressociation studies prove that foldback DNA and highly repeated sequences are much more frequent in the satellite DNA fraction than in the mainband DNA.
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http://dx.doi.org/10.1007/BF00392722 | DOI Listing |
Genet Mol Biol
January 2025
Instituto Nacional de Pesquisas da Amazônia, Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva (PPG GCBEv), Manaus, AM, Brazil.
Centromochlus heckelii has the lowest diploid chromosome number (2n = 46) and the only described heteromorphic sex chromosome system in Auchenipteridae. This study presents a population of C. heckelii from the Central Amazon basin with subtle variations in the karyotype composition and a variant W chromosome with distinct morphology and increased C-positive heterochromatin content.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
College of Chemistry and Chemical Engineering, Jishou University, Jishou, Hunan 416000, P. R. China.
Detecting β-lactoglobulin (β-Lg) with high sensitivity and selectivity is an urgent requirement due to nearly 80% of milk anaphylaxis, such as respiratory tract, skin urticaria, and gastrointestinal disorders, being caused by β-Lg. An ultrasensitive β-Lg electrochemical aptasensor utilizing core-satellite gold nanoparticle@silver nanocluster (AuNPs@AgNCs) nanohybrids as electrocatalysts was developed. First, β-Lg aptamer was anchored on gold electrodes and AuNPs to obtain high selectivity.
View Article and Find Full Text PDFDiagnostic delays prevent most Chagas disease patients from receiving timely therapy during the acute phase when treatment is effective. qPCR-based diagnostic methods provide high sensitivity during this phase but require specialized equipment and complex protocols. More simple and cost-effective tools are urgently needed to optimize early Chagas disease diagnosis in low-income endemic regions.
View Article and Find Full Text PDFGenes (Basel)
January 2025
Laboratório de Citogenética de Insetos, Departamento de Biologia Geral, Universidade Federal de Viçosa, Campus Universitário, Viçosa 36570-900, Minas Gerais, Brazil.
Background/objectives: A striking feature of the karyotypes of stingless bees is the large amount of heterochromatin present in most species. Cytogenomic studies performed in some Meliponini species have suggested that evolutionary events related to the diversification and amplification of satellite DNA families in the heterochromatin may reflect the structuring of phylogenetic clades in this tribe. In this study, we performed a genomic analysis in to characterize different satDNA families in its genome.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Experimental Biology, Genetics Area, University of Jaén, Campus Las Lagunillas s/n, 23071, Jaén, Spain.
Acanthocephalan parasites are often overlooked in many areas of research, and satellitome and cytogenetic analyzes are no exception. The species of the genus Acanthocephalus are known for their very small chromosomes with ambiguous morphology, which makes karyotyping difficult. In this study, we performed the first satellitome analysis of three Acanthocephalus species to identify species- and chromosome-specific satellites that could serve as cytogenetic markers.
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