The present application relates to a method of recombinantly engineering a Leishmania cell that involves homologous recombination of DNA fragments. Further provided herein are Leishmania cells recombinantly engineered using the method provided herein. Also provided herein are methods of making a polypeptide using a Leishmania cell described herein and polypeptides produced by the methods provided herein.

Described is an assay termed Programmable Enzyme-Assisted Selective Exponential Amplification (PASEA) that concurrently amplifies both wild type and mutant alleles while selectively cleaving the former. With time, the rare mutant alleles dominate, and are readily detectable by direct detection, Sanger sequencing, and other readily available methods. Also described are point-of-care assays and microfluidic devices for performing PASEA.

The present application relates to the identification of novel DNA methyltransferases including CHG methylation in algal species. The present application relates to algal mutants permitting the expression of exogenous genes by alleviating the epigenetic mechanisms of CHG and CHH methylation of exogenous DNA and mono- and tri-methylation of lysine 9 of histone 3 (H3K9). This is achieved by mutating or attenuating the methyltransferase (MTase) genes in algae. The present application also relates to methods for efficiently expressing exogenous genes in algal species.

A method of modifying a gene encoding or processed into a non-coding RNA molecule having no RNA silencing activity in a plant cell is disclosed. The method comprising introducing into the plant cell a DNA editing agent conferring a silencing specificity of the non-coding RNA molecule towards a target RNA of interest. A method of modifying a gene encoding or processed into a RNA silencing molecule in a plant cell is also disclosed. The method comprising introducing into the plant cell a DNA editing agent which redirects the silencing specificity of the non-coding RNA molecule towards a target RNA of interest. Plant cells, plant seeds, plants, and methods of generating plants are also disclosed.

The present disclosure provides engineered Class 1 Type I CRISPR-Cas (Cascade) systems that comprise multi-protein effector complexes, nucleoprotein complexes comprising Type I CRISPR-Cas subunit proteins and nucleic acid guides, polynucleotides encoding Type I CRISPR-Cas subunit proteins, and guide polynucleotides. Also, disclosed are methods for making and using the engineered Class 1 Type I CRISPR-Cas systems of the present invention.

Information is stored in existing DNA through an iterative process of creating a break in dsDNA and adding new DNA by repairing the break with a homologous repair template. The order and sequence of DNA sequences added to the breaks in the dsDNA can encode binary data. By using a context-dependent encoding scheme, three unique homologous repair templates can encode an unbounded number of bits. When the existing DNA is in a cell, the changes are heritably passed to subsequent generations of the cell. Synthesis of the homologous repair templates may be under the control of a promoter and operator. Intra- or extra-cellular signals may regulate the synthesis of homologous repair templates.

A log of molecular events experienced by a cell and timing indicators for those events are stored in existing polynucleotides through a process of creating a double strand break (“DSB”) in a polynucleotide and inserting a new polynucleotide sequence by repairing the DSB with homology directed repair (“HDR”). The presence, order, and number of new polynucleotide sequences provides a log of events and timing of those events. Cellular mechanisms for creating the DSB and/or repairing with HDR are regulated by intra- or extra-cellular signals. When the log is created in the DNA of a cell, the changes may be heritably passed to subsequent generations of the cell. A correlation between the cellular signals and sequence of inserted HDR templates allows for identification of events and the timing experienced by the cell.

A molecular state machine is implemented in a cell by designing the cell to use specific homology directed repair (“HDR”) templates for repairing double strand breaks in polynucleotides based on a current “state” of the cell. The state may be established by the presence of a molecule in the cell or by the availability of specific cut sites in the polynucleotides of the cell. Different HDR templates or different nucleases may be available for performing HDR based on the state. When the state is changed, the same signal or event will result in a different HDR template being incorporated into the existing polynucleotides of the cell. Signals that are internal or external to the cell may be used to change the state of the cell. The cell may create a log of molecular events, store binary data, or perform other synthetic biology/molecular computing functions based on state.

The present invention relates to the field of molecular biology and cell biology. More specifically, the present invention relates to a CRISPR-CAS system for a yeast host cell.

The invention provides methods and means for specifically altering the DNA sequence in a genome, in particular for genome editing by deleting or replacing a sequence of interest. Advantageously, the invention uses two non-identical sequences naturally occurring in a genome as target sites two which DNA-recombining enzymes are generated. The invention is in particular useful for medicine, in particular to repair a mutation in a genome or to delete predefined genetic material from cells or tissue and to cure diseases. An advantage of the invention is that it allows precise site directed altering of DNA without engaging host DNA repair pathways and thereby works without inducing random insertions and deletions (in-dels).