The invention relates to non-integrative lentiviral vectors and their use for the stable transgenesis of both dividing and no-dividing eukaryotic cells. The invention also provides methods for obtaining these vectors, the use of these vectors for the production of recombinant lentiviruses, and the use of these recombinant lentiviruses for obtaining a cell able to stably produce a product of interest.

Certain embodiments are directed to compositions and methods for capture of elements in physical proximity. In certain aspects the methods comprise (a) contacting a target with a functionalized scaffold or capture agent that comprises activatable cross-linking moieties to form a target/scaffold mixture; (b) exposing the target/scaffold mixture to an activator to activate the cross-linking moieties of the dendrimer and form a cross-linked target/scaffold complex; (c) isolating the target/scaffold complexes; and (d) identify portions of the target or targets that are cross linked with the scaffold.

The invention relates to a minimal U6 pol III promoter. The invention also concerns a nucleic acid construct comprising the minimal U6 pol III promoter, a vector comprising the minimal U6 pol III promoter, methods involving the minimal U6 pol III promoter, and uses for the minimal U6 pol III promoter.

Embodiments are directed to N.sub.3-kethoxal reagents and derivatives thereof, and related methods that allow fast and reversible labeling of single-stranded nucleic acids in live cells. By way of example, one aspect is directed to a process for reversible labeling of single-stranded guanine bases in live cells, which results in an effective in vivo method for transcriptome-wide RNA secondary structure mapping and RNA G-quadruplex prediction.

The present disclosure relates to new identified matrix attachment regions (MAR) and chimeric sequences. Also disclosed are nucleotide constructs containing a MAR at a suitable location relative to a protein-coding sequence for optimal expression of the protein.

Embodiments are directed to N.sub.3-kethoxal reagents and derivatives thereof, and related methods that allow fast and reversible labeling of single-stranded nucleic acids in live cells. By way of example, one aspect is directed to a process for reversible labeling of single-stranded guanine bases in live cells, which results in an effective in vivo method for transcriptome-wide RNA secondary structure mapping and RNA G-quadruplex prediction.

A novel ubiquitous chromatin opening element (UCOE) named SRF-UCOE and methods for its use are provided. Compositions including recombinant and synthetic SRF-UCOE nucleic acid molecules, DNA constructs and vectors comprising the SRF-UCOE nucleic acid molecules, host cells comprising the DNA constructs or vectors, and cell culture systems comprising such host cells. SRF-UCOE polynucleotide sequences can be used in DNA constructs or expression cassettes for transformation and expression in cells or organisms of interest. The compositions and methods provided are useful for increasing and/or maintaining expression of a gene of interest. Transgenic cells, tissues, and animals comprising a SRF-UCOE nucleotide sequence are also provided. Methods are provided for increasing and/or maintaining expression of a gene of interest and for treating a subject via gene therapy.

The present disclosure relates to new identified matrix attachment regions (MAR) and chimeric sequences. Also disclosed are nucleotide constructs containing a MAR at a suitable location relative to a protein-coding sequence for optimal expression of the protein.