Conditional Rat Model Generation FREE Custom Cre Rats with Purchase

Compared with constitutively expressed gene mutations, conditional models provide greater temporal and regional control of gene expression. Here below are the three commonly used methods to generate conditional rat models:

• Developing Conditional Rats Using Cre-Lox Recombination

  The Cre/lox recombination system enables the generation of tissue-specific or inducible knockouts with a high level of control over the spatial and temporal expression of genes. However, considering that Cre rats need to be crossed with LoxP rats for one to two generations to obtain conditional gene-editing animals alongside the fact that Cre enzymes have inefficiencies and probability of leakage - the breeding approach may affect the progress of scientific research. To address these potential drawbacks, virus-induced overexpression/knockout (KO)/knock-in (KI) /point mutation of rat models came into being.

• Developing Conditional Rats Using Viral Vector Expression Systems

  Currently, there are three main viral vector expression systems in use, namely adenovirus, lentivirus, and adeno-associated virus (AAV). These viral systems have their own advantages and disadvantages:

  

  Based on the comparison of the above three viral vector expression systems for the generation of conditional gene expression animal models, it may be concluded that AAV vector-mediated tissue-specific expression has a better effect than the other two viral systems.

• Combining AAV with Cre/LoxP for Generation of Conditional Models

  In recent years, Cre-LoxP animals have matured in the study of the spatial specificity of genes, and there are even cases where the transferred promoters are expressed in multiple tissues simultaneously. For tissue-specific Cre expression models, the expression of Cre in other areas would interfere with the accuracy of research results. This problem can be solved with the fixed-point injection of AAV, which demonstrates a very strong regional specificity, into the target tissues.

  To make better use of the gene-editing mice on hand, the AAV injection protocol can be divided into two types:

  1) If you have LoxP rats already, you can inject with AAV packaging tissue-specific Cre;

  2) Conversely, if you have Cre rats, the virus can be injected with the target gene or other elements connected to the LoxP site.

  In general, a tissue-specific promoter for Cre recombinase with AAV Packaging is more commonly used.

• Mouse and Rat Breeding

  Cyagen’s breeding service provides reliable, economical, and efficient breeding colonies of mice/rats to support your research needs; allowing you to focus more on your research goals and less on animal care, breeding and colony management issues.

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• Cryopreservation

  Cyagen can back up your live animal colony by our embryo and sperm cryopreservation services, which can not only protect your valuable strains but also reduce your cost in the long run. We also can produce live animals for you in eight to twelve weeks once your cryopreserved stock is preserved at Cyagen.

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• Phenotype Analysis Services

  Our phenotyping services include surgical model construction alongside analytics capabilities for blood, tissue histology and morphology, pathology, genomic and proteomic expression, behavioral and metabolic analysis, and more.

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• BAC Modification (Recombineering)

  We can fulfill all your BAC modification needs with rapid turnaround and unbeatable prices. We can place reporters behind regulatory sequences on the BAC, introduce point mutations into genes of interest, transfer regions of the BAC onto a plasmid, and add drug-selection or visualization markers to the BAC backbone. We guarantee the successful modification of your BAC, or your money back.

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  Please contact us if you need additional information.

• TurboKnockout^® - Proprietary Method for Accelerated Generation of Precise Mouse Models

  Cyagen’s Proprietary Method for Accelerated Generation of Precise Mouse Models

  Our proprietary TurboKnockout^® gene targeting method can provide you with conditional knockout, reporter knockin and humanization mouse models as fast as 6-8 months. This proprietary gene targeting method is enabled by two innovations:

  • ● Eliminates the unpredictability of germline transmission (GLT)with our super competent ESC line that generates 100% ESC-derived founder mice rather than chimeras.
  • ● Self-removing selection cassette circumvents the need to breed to Flp deleter mice

  These innovations eliminate at least two generations of breeding, shortening production time by 4-6 months as compared to the industry standard

   

  Highlights of TurboKnockout^® Gene Targeting

  TurboKnockout^® gene targeting: 6-8 months

  • Targeting Vector
    Construction

    2 months

  • Gene Targeting
    in ES Cells

    2-3 months

  • Founder Het
    Generation

    2-3 months

  Traditional gene targeting: 10-14 months

  • Targeting Vector
    Construction

    2 months

  • Gene Targeting
    in ES Cells

    2-3 months

  • Chimera
    Generation

    2-3 months

  • F1 Het
    Generation

    2-3 months

  • Removal of
    Selection Cassette

    2-3 months

   

  Highlights of TurboKnockout^® Gene Targeting

  • ● No patent risk: Technology of choice for drug development projects
  • ● Success rate: 100% guaranteed germline transmission (GLT)
  • ● Turnaround time: Founders as fast as 6-8 months
  • ● Large fragment knockin size: Knockin (KI) fragment size up to 200 kb
  • ● Limitless loxP: No size limitations for your floxed region
  • ● 100% Money-Back Guarantee on TurboKnockout^® projects

   

  Capabilities

  

   

  Donor Strains Mouse: C57BL/6, BALB/c
• Cyagen CRISPR-Pro Technology - Capabilities for Mouse & Rat Models

  Engineered nuclease-mediated genome editing (especially CRISPR/Cas9) is an emerging technology which can serve as an alternative to the conventional, ES cell homologous recombination-based knockout (KO) animal generation. These methods have enabled the generation of custom mouse and rat models with genetic knockouts, point mutations, and large fragment knockins (LFKIs).

  Cyagen’s CRISPR-based Rapid Knockout services use accelerated methodology that provides conventional knockout, reporter knockin, and humanization founder animals in as fast as 3 months.

   

  Capabilities

  

   

  Donor Strain Information:

  • ● Mouse strains: C57BL/6, FVB
  • ● Rat strains: Sprague-Dawley (SD), Long Evans
  • Note: Other strains available upon request.
• Transgenic Capabilities for Animal Models

  Items	Regular Transgenic	PiggyBac Transgenic	Rosa26 Targeted Transgenic
  Integration	Random, multicopy integration	Random, single copy per integration site	Single copy transgene targeted to Rosa26 safe harbor locus
  Vector construction	Plasmid or BAC	Plasmid or BAC	CRISPR or TurboKnockout®
  Expression pattern	Variable	More consistent	Most consistent
  Endogenous effects	Can disrupt endogenous genes	Less likely to disrupt endogenous genes	Safe harbor locus
  Donor Strain Information	Mouse strains: C57BL/6, FVB Rat strains: Sprague-Dawley (SD), Long Evans Note: Other strains available upon request.

  PiggyBac transgenic services can deliver single-copy transgenic animals with more consistent expression of your transgene. This proprietary transgenic method has the following advantages over other transgenic approaches:

  ◆ Single-copy integration: Avoids potential gene silencing from multiple copies
  ◆ Defined region of integration: No loss of transgene sequence (TTAA, transcription unit)
  ◆ Reliability: More consistent expression pattern compared to plasmid based transgenics
  ◆ Economical: Cost and turnaround time comparable to plasmid based transgenics