The transduction of an Escherichia coli gene into mammalian cells is described. A supressor tRNA gene was linked to a simian virus 40 (SV40) vector in vitro and the recombinant was used to transfect rat embryo cells and monkey kidney cells. The hybrid SV40 genome, SV40-su+ III, retained genetic information required for autonomous replication and cellular transformation and had a 1300-base-pair DNA segment in the late gene region (between the restriction endonuclease sits Hpa II at 0.735 and EcoRI at 0/1.0 on the SV40 genetic map) replaced by an 870-base-pair bacterial DNA segment containing the suppressor tRNA gene, su+ III (tRNATyrsu+III). The structure and fate of the SV40-su+III chimera were determined by DNA reassociation kinetic analysis and restriction enzyme cleavage of the total cellular DNA from transformed rat embryo cells and persistently infected monkey cells. Hybridization with radiolabeled probes specific for vector (SV40) or su+III DNA sequences revealed primarily nonintegrated or free hybrid genomes. In cloned lines of both cell types, the bacterial DNA segment was recovered intact, as judged by the length of the segment excised by restriction endonucleases and its ability to hybridize to the radiolabeled bacterial DNA probe and not to the SV40 probe.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC392502 | PMC |
http://dx.doi.org/10.1073/pnas.75.5.2117 | DOI Listing |
Trop Med Health
January 2025
Department of Vector Biology and Control of Diseases, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Background: The Anopheles culicifacies complex is one of the most important malaria vectors in Southeast Asia and Southeastern Iran. Although the sibling species within this complex are morphologically indistinguishable, they differ significantly in their disease transmission potential, blood-feeding behaviour, and other biological traits. Cytogenetic and chromosomal studies have identified five sibling species within this complex: A, B, C, D, and E.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Primate Behavioral Ecology, Institute of Biology, Leipzig University, Leipzig 04103, Germany.
Biological relatedness is a key consideration in studies of behavior, population structure, and trait evolution. Except for parent-offspring dyads, pedigrees capture relatedness imperfectly. The number and length of identical-by-descent DNA segments (IBD) yield the most precise relatedness estimates.
View Article and Find Full Text PDFTalanta
January 2025
School of Life Science, Jiangsu Normal University, Xuzhou, 221116, China.
Sensitive and accurate detection and imaging of different microRNAs (miRNAs) in cancer cells hold great promise for early disease diagnosis. Herein, a DNA tetrahedral scaffold (DTS)-corbelled autonomous-motion (AM) molecular machine based fluorescent sensing platform was designed for simultaneous detection of two types of miRNAs (miRNA-21 and miRNA-155) in HeLa cells. Locking-strand-silenced DNAzymes (P:L duplex) were firstly grafted at the loop of target-analogue-embedded double-stem hairpin substrates (TDHS) of DTS, making the sensor in a "signal off" state due to the closely distance between modified fluorophores (FAM and Cy5) with the corresponding quenchers (BHQ1 and BHQ2).
View Article and Find Full Text PDFWe present a comprehensive genetic investigation of Late Neolithic (LN) and Early Copper Age (ECA) populations living in the Carpathian Basin, leveraging whole genome data from 125 previously unreported individuals. Using population genetics, kinship analyses and the study of networks of identity-by-descent haplotype segment sharing, we elucidate the social and genetic dynamics of these communities between 4800-3900 cal BCE. Despite changes in settlement patterns, burial practices, and material culture, we document a high degree of genetic continuity.
View Article and Find Full Text PDFHortic Res
January 2025
Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, Key Laboratory of Oasis Town and Mountain-basin System Ecology of Xinjiang Production and Construction Corps, College of Life Sciences, Shihezi University, Shihezi 832003, China.
Alfalfa is one of the most economically valuable forage crops in the world. However, molecular cytogenetic studies in alfalfa lag far behind other cash crops and have reached a bottleneck. Here, we developed a novel chromosome identification system by designing 21 oligo probes in specific regions of each chromosome, which can be used as a barcode to simultaneously distinguish all chromosomes in a cell.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!