ISO 5058-1:2021 バイオテクノロジー—ゲノム編集—パート1：用語, 語彙 | ページ 6

3.1.1

遺伝子編集

部位特異的修飾を遺伝子に組み込むための核酸損傷、修復機構、複製および/または組換えを含む ゲノム工学 (3.1.3) の技術

注記1:遺伝子編集は ゲノム編集 (3.1.2) のサブクラスである。

注記 2:さまざまなゲノム編集ツールがあります (3.2 および図 1 を参照)

3.1.2

ゲノム編集

部位特異的修飾をゲノム DNA に組み込むための核酸損傷、修復メカニズム、複製および/または組換えを含む ゲノム工学 (3.1.3) の技法

注記1： 遺伝子編集（3.1.1） はゲノム編集のサブクラスである。

3.1.3

ゲノム工学

ゲノム核酸に意図的な変更を導入するプロセス

注記 1: 遺伝子編集 (3.1.1) および ゲノム編集 (3.1.2) は、ゲノム工学で使用される技術です。

3.1.4

的外れの

オフターゲットゲノム編集

標的とは異なるゲノム位置および/または核酸配列 (3.1.6)

注記 1:対象外の編集は、 意図しない編集の例です (3.3.7) 。

3.1.5

特異性

ゲノム編集標的特異性

編集エージェントまたは編集手順が意図した ターゲットのみに作用する程度 (3.1.6)

注記1:この用語を使用する場合、手順が定義され、意図されたターゲットが定義され、アクションまたは結果が測定および報告され、検出限界が報告されます。

3.1.6

目標

ゲノム編集ターゲット

ゲノム編集（3.1.2） プロセス中に意図的な結合、修飾、および/または切断を受ける核酸配列

注記 1: オフターゲット (3.1.4) 、 Cas ヌクレアーゼ標的部位 (3.2.2.2) 、 メガヌクレアーゼ標的部位 (3.2.3.4) 、 メガタル標的部位 (3.2.4.3) 、 TALEN 標的部位 (3.2. 5.4) および ZFN ターゲット サイト (3.2.6.5) 。

3.2.1.1

修理テンプレート

標的またはその近くで特定の DNA 配列の変化を組み込むように細胞 DNA 修復経路を指示するために使用される核酸配列 (3.1.6)

3.2.1.2

部位特異的 DNA 修飾酵素

特定の配列でDNAを修飾できる酵素

3.2.1.3

部位特異的ヌクレアーゼ

配列特異的ヌクレアーゼ

酵素:特定の配列で核酸ポリマーの隣接するヌクレオチド間のホスホジエステル結合を切断できる

3.2.2.1

Cas nuclease

CRISPR associated nuclease

enzyme that is a component of CRISPR systems that is capable of breaking the phosphodiester bonds between nucleotides

Note 1 to entry: Some but not all Cas nucleases interact with a gRNA (3.2.2.4) . See also crRNA (3.2.2.3) , sgRNA (3.2.2.7) and tracrRNA (3.2.2.9) .

3.2.2.2

Cas nuclease target site

nucleotide sequence comprising the PAM (3.2.2.5) , in most cases, and a region that hybridizes to the target sequence specific guide of a Cas RNP (3.2.2.6)

3.2.2.3

crRNA

CRISPR RNA

polyribonucleotide that includes sequence complementarity to the target (3.1.6) and a sequence that interacts with a Cas protein and optionally tracrRNA (3.2.2.9)

Note 1 to entry: crRNA is a component of g RNA (3.2.2.4) or a complete gRNA, depending on the CRISPR system.

Note 2 to entry: In some CRISPR systems, a portion of the crRNA will base-pair with the tracrRNA (e.g. Cas9). Other CRISPR systems lack tracrRNA (e.g. Cas12a/Cpf1). In systems that do not require tracrRNA, the gRNA is called a “CRISPR RNA” or simply “crRNA”.

3.2.2.4

gRNA

guide RNA

polyribonucleotide containing regions sufficient for productive interaction with a Cas nuclease (3.2.2.1) or variant to direct interaction with the specific target (3.1.6)

Note 1 to entry: See crRNA (3.2.2.3) , tracrRNA (3.2.2.9) and sgRNA (3.2.2.7) .

Note 2 to entry: For Cas9-type proteins, the natural gRNA comprises a crRNA that imparts sequence specificity and the tracrRNA that interacts with and activates the protein. This is sometimes referred to as a “dual guide”. Other Cas proteins can have different gRNA structures.

Note 3 to entry: sgRNA for Cas9 proteins are non-naturally occurring polyribonucleotides where the crRNA and tracrRNA are fused with an artificial linker.

Note 4 to entry: In some cases, chemical modifications of the polyribonucleotide are used, such as modifications to the phosphodiester linkages, bases or sugar moieties. These can include substitution of DNA (2′-deoxy) or 2′-methoxy nucleotides for RNA nucleotides, etc.

3.2.2.5

PAM

protospacer adjacent motif

short nucleotide motif in the targeted region of nucleic acid required for guided Cas nuclease (3.2.2.1) or variant binding

Note 1 to entry: PAMs are distinct from, but in close proximity to, nucleic acid sequence targeted by g RNA (3.2.2.4) .

3.2.2.6

RNP

ribonucleoprotein

complex comprising protein bound to RNA

Note 1 to entry: In the context of CRISPR-based genome editing (3.1.2) , RNP refers to the complex of Cas protein(s) and g RNA (3.2.2.4) .

3.2.2.7

sgRNA

single-guide RNA

fusion of crRNA (3.2.2.3) and tracrRNA (3.2.2.9)

Note 1 to entry: See g RNA (3.2.2.4) .

3.2.2.8

target strand

CRISPR target strand

single-stranded nucleic acid sequence that is complementary to the g RNA (3.2.2.4) of a Cas protein or variant

3.2.2.9

tracrRNA

trans-activating CRISPR RNA

polyribonucleotide that base-pairs with the crRNA (3.2.2.3) and interacts with a Cas nuclease (3.2.2.1) to enable sequence-specific interaction of the target (3.1.6)

Note 1 to entry: tracrRNA is an optional component of g RNA (3.2.2.4) .

3.2.3.1

meganuclease

variant of the LAGLIDADG subtype of homing endonucleases engineered to recognize a 15 to 40 base pair DNA target (3.1.6) different from the site recognized by the parent endonuclease

Note 1 to entry: The LAGLIDADG consensus sequence represents an alpha helix that serves as a dimerization interface and key component in the DNA cleavage site in this family of meganucleases.

3.2.3.2

meganuclease linker

natural or artificially derived polypeptide sequence that links two LAGLIDADG domains to one another to form a single polypeptide chain

Note 1 to entry: The LAGLIDADG consensus sequence represents an alpha helix that serves as a dimerization interface and key component in the DNA cleavage site in this family of meganucleases (3.2.3.1) .

3.2.3.3

meganuclease single chain

meganuclease (3.2.3.1) composed of two LAGLIDADG domains joined by either a natural or artificially derived polypeptide linker in order to be expressed as a single polypeptide chain

Note 1 to entry: The LAGLIDADG consensus sequence represents an alpha helix that serves as a dimerization interface and key component in the DNA cleavage site in this family of meganucleases.

3.2.3.4

meganuclease target site

DNA sequence recognized by meganucleases (3.2.3.1)

Note 1 to entry: Meganuclease target sites are 15 to 40 base pair DNA sequence consisting of two equal length half sites separated by a 4 base pair middle sequence (also known as “central 4”). Cleavage occurs at the junction of the half sites and the middle site on each DNA strand leaving a 4 nucleotide 3′ overhang.

3.2.4.1

megaTAL

artificial chimeric nucleases composed of an array of transcription activator-like (TAL) effector (TALE)^[1] DNA binding domains, a megaTAL linker (3.2.4.2) and a meganuclease (3.2.3.1)

3.2.4.2

megaTAL linker

amino acid sequence that links an array of TAL DNA binding domains and a meganuclease (3.2.3.1)

3.2.4.3

megaTAL target site

intended DNA binding site of a megaTAL (3.2.4.1) , encompassing the DNA sequence targeted by both the TAL array and the meganuclease (3.2.3.1)

3.2.5.1

RVDs

repeat variable diresidue

two amino acid sequence in TAL repeats that imparts DNA binding specificity

3.2.5.2

TALEN

transcription activator-like effector nuclease

artificial nuclease composed of an endodeoxyribonuclease fused to DNA-binding domains of TALEs^[1] that cleave DNA at a defined distance from TALE recognition sequences

Note 1 to entry: A TALEN can refer to a pair of TALE-FokI fusion proteins that dimerize on opposite strands of DNA adjacent to a target (3.1.6) for cleavage.

3.2.5.3

TALEN linker

polypeptide sequence that links an array of TAL DNA binding domains and an endodeoxyribonuclease, typically FokI

3.2.5.4

TALEN target site

DNA sequence recognized by TALENs (3.2.5.2)

Note 1 to entry: Typical TALEN target sites are recognized by a pair of TALENs and contain a central spacer region flanked by upstream and downstream sequences that are each recognized by one TALEN. This pair is designed in such a way that two TALEN nuclease domains dimerize to cleave DNA within the spacer region.

3.2.6.1

zinc finger

Cys2His2 zinc finger

DNA binding domain that folds via coordination of zinc into a compact structure consisting of two beta strands and one alpha-helix (β β α)

Note 1 to entry: Zinc finger DNA binding domains typically contain 28 amino acids.

3.2.6.2

ZFN

zinc finger nuclease

chimeric protein consisting of an array of zinc fingers (3.2.6.1) linked to a DNA cleavage domain

Note 1 to entry: FokI is prevalently used as the DNA cleavage domain bound to a zinc finger.

Note 2 to entry: Binding of two ZFNs to a pair of appropriately spaced DNA target sites enables nuclease domain dimerization and DNA cleavage between the targets.

3.2.6.3

ZFN linker

polypeptide sequence that links an array of zinc finger (3.2.6.1) binding domains and a DNA cleavage domain

Note 1 to entry: FokI is prevalently used as the DNA cleavage domain bound to a zinc finger.

3.2.6.4

ZFN recognition helix

seven residue positions within a zinc finger (3.2.6.1) that are most directly responsible for its DNA binding preference

Note 1 to entry: The seven residues comprise the first six residues of the alpha helix, along with the residue immediately preceding the N-terminal of the helix. They are typically referred to as positions +1 to +6 (within the alpha helix) and position (−1) (immediately preceding the helix).

3.2.6.5

ZFN target site

DNA sequence recognized by a pair of ZFNs (3.2.6.2)

Note 1 to entry: Typical ZFN target sites contain a central spacer region flanked by DNA sequences that are each recognized by an array of zinc fingers (3.2.6.1) oriented such that the ZFN nuclease domains dimerize and cleave within the spacer.

3.2.6.6

ZFP

zinc finger protein

DNA binding protein consisting of a tandem array of multiple zinc fingers (3.2.6.1)

3.3.1

edit

DNA edit

RNA edit

epigenome edit

DNA, RNA or epigenome edit

modification to nucleic acid sequence resulting from the application of genome editing (3.1.2) components

Note 1 to entry: Genome editing components can include a nuclease and repair template (3.2.1.1) .

3.3.2

HDR

homology-directed repair

mechanism of recombinational DNA repair^[2] where repair is templated by a polynucleotide with regions corresponding to sequences flanking the target (3.1.6)

Note 1 to entry: Repair templates (3.2.1.1) can be exogenously introduced to achieve sequence changes in genome editing (3.1.2) approaches.

3.3.3

indel

InDel mutation

sequence change caused by the insertion and/or deletion of nucleotides

3.3.4

intended edit

designed modification to a target (3.1.6) resulting from the application of genome editing (3.1.2) components

Note 1 to entry: See edit (3.3.1) .

Note 2 to entry: Genome editing components can include a nuclease and repair template (3.2.1.1) .

3.3.5

MMEJ

microhomology-mediated end joining repair

mechanism of DNA end-joining repair^[3] where the DNA ends are rejoined to each other using short regions of homology flanking the initiating double-stranded break to align the ends for repair

Note 1 to entry: MMEJ repair of DNA breaks in genome editing (3.1.2) approaches can result in deletion between pairs of microhomology regions.

Note 2 to entry: Short regions of homology for MMEJ are typically 2 to 25 base pairs.

3.3.6

NHEJ

non-homologous end joining

mechanism of DNA end-joining repair^[3] in which DNA ends are joined in a homology-independent manner

Note 1 to entry: NHEJ repair of DNA breaks in genome editing (3.1.2) workflows can result in indel (3.3.3) formation.

3.3.7

unintended edit

modification to nucleic acid at an off-target (3.1.4) resulting from the application of genome editing (3.1.2) components

Note 1 to entry: See edit (3.3.1) .

Note 2 to entry: Genome editing components can include a nuclease and repair template (3.2.1.1) .