Source 1primary paper2025MED
Toolkit/gp64 variant calling methodology
gp64 variant calling methodology
Also known as: sequencing pipeline, variant calling methodology
Taxonomy: Technique Branch / Method. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
we describe a variant calling methodology that allows the detection of the targeted mutations in gp64 even though these mutations are not the dominant sequences... our sequencing pipeline successfully detected indel mutations within gp64 for most of the single-guide RNA (sgRNA) targets
Usefulness & Problems
No literature-backed usefulness or problem-fit explainer has been materialized for this record yet.
Published Workflows
Objective: Assess transient CRISPR-Cas9 disruption of baculovirus gp64 at different gene locations to reduce baculovirus co-production while preserving recombinant protein production and to detect resulting edits by sequencing-based variant calling.
Why it works: The workflow couples transient CRISPR-Cas9 targeting of an essential baculovirus gene with sequencing-based detection of minority edited variants, allowing the authors to assess both production phenotypes and edit outcomes despite incomplete genome disruption.
disruption of gp64, a baculovirus envelope glycoprotein required for entry and cell-to-cell transmissionindel generation within gp64 by CRISPR-Cas9 targetingtransfection-infection assaysingle and multiple sgRNA targetingviral genome isolation from supernatant and cell pellet fractionssequencing-based variant calling
Stages
- 1.gp64 targeting design and assay setup(library_design)
This stage establishes the set of gp64 targeting conditions to evaluate how target location and multiplicity affect baculovirus reduction and protein production.
Selection: Target the AcMNPV gp64 gene at six different locations using single and multiple targeting sites.
- 2.cell-based functional assessment(functional_characterization)
This stage tests whether gp64 targeting achieves the manufacturing-relevant objective of lowering baculovirus co-production without compromising recombinant protein output.
Selection: Assess reduction in baculovirus vector levels together with maintenance or enhancement of foreign protein production.
- 3.viral genome isolation and sequencing readout(sequencing_readout)
This stage confirms that targeted indels occurred in gp64 and addresses the fact that edited genomes may be minority variants.
Selection: Isolate viral genomes from supernatant and cell pellet fractions and detect gp64 indels by sequencing.
- 4.propagation-based variant conservation assessment(confirmatory_validation)
This stage tests whether detected variants persist during propagation, which the authors interpret as evidence that they are not detrimental to viral fitness.
Selection: Evaluate whether variants found in virus stock are conserved upon propagation in cell culture.
Steps
- 1.Target AcMNPV gp64 at six locations in a transfection-infection assayassay framework
Set up single and multiple gp64 targeting conditions for comparative evaluation.
Targeting conditions must be established before phenotypic and sequencing outcomes can be measured.
- 2.Measure baculovirus vector levels and foreign protein production
Determine whether gp64 targeting reduces baculovirus vectors while preserving or improving recombinant protein output.
Functional production outcomes are assessed after targeting to identify whether the engineering objective is met before molecular confirmation.
- 3.Isolate viral genomes from supernatant and cell pellet fractions
Prepare viral genetic material for sequencing-based detection of gp64 edits.
Genome isolation is required before the sequencing pipeline can assess whether targeted indels were generated.
- 4.Detect gp64 indel mutations with the sequencing pipelinevariant detection method
Confirm targeted editing in gp64, including minority edited variants.
This analysis follows genome isolation and is needed because not all genomes are effectively disrupted and edited variants may not be dominant.
- 5.Assess conservation of detected variants after propagation in cell culture
Evaluate whether detected variants persist during propagation as an indicator of compatibility with viral fitness.
Variant conservation can only be tested after variants have first been detected in virus stock.
Taxonomy & Function
Primary hierarchy
Technique Branch
Method: A concrete computational method used to design, rank, or analyze an engineered system.
Target processes
No target processes tagged yet.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
Transient CRISPR-Cas9 targeting of AcMNPV gp64 at six locations reduced baculovirus vector levels while maintaining or enhancing foreign protein production when expression was driven by a p6.9 promoter.
Using a transfection-infection assay (T-I assay), the AcMNPV gp64 gene was targeted at six different locations to evaluate the effects of single and multiple targeting sites, and we demonstrated a reduction in the levels of baculovirus vectors while maintaining or enhancing foreign protein production when protein was driven by a p6.9 promoter.
The paper describes a variant calling methodology that can detect targeted gp64 mutations even when edited genomes are not the dominant sequence population.
we describe a variant calling methodology that allows the detection of the targeted mutations in gp64 even though these mutations are not the dominant sequences
The sequencing pipeline detected indel mutations within gp64 for most sgRNA targets.
our sequencing pipeline successfully detected indel mutations within gp64 for most of the single-guide RNA (sgRNA) targets
A majority of variants found in virus stock were conserved after propagation in cell culture, suggesting those variants were not detrimental to viral fitness.
We also observed that 68.8% of variants found in the virus stock were conserved upon virus propagation in cell culture, thus indicating that they are not detrimental to viral fitness.
variant conservation after propagation 68.8 %
Approval Evidence
1 source3 linked approval claimsfirst-pass slug gp64-variant-calling-methodology
we describe a variant calling methodology that allows the detection of the targeted mutations in gp64 even though these mutations are not the dominant sequences... our sequencing pipeline successfully detected indel mutations within gp64 for most of the single-guide RNA (sgRNA) targets
Source:
method capabilitysupports
The paper describes a variant calling methodology that can detect targeted gp64 mutations even when edited genomes are not the dominant sequence population.
we describe a variant calling methodology that allows the detection of the targeted mutations in gp64 even though these mutations are not the dominant sequences
Source:
sequencing detection resultsupports
The sequencing pipeline detected indel mutations within gp64 for most sgRNA targets.
our sequencing pipeline successfully detected indel mutations within gp64 for most of the single-guide RNA (sgRNA) targets
Source:
variant conservationsupports
A majority of variants found in virus stock were conserved after propagation in cell culture, suggesting those variants were not detrimental to viral fitness.
We also observed that 68.8% of variants found in the virus stock were conserved upon virus propagation in cell culture, thus indicating that they are not detrimental to viral fitness.
Source:
Comparisons
No literature-backed comparison notes have been materialized for this record yet.
Ranked Citations
- 1.