Phenylketonuria (PKU) Animal Model Service
Phenylketonuria (PKU) animal models are indispensable for elucidating the neuropathological mechanisms of hyperphenylalaninemia and providing crucial platforms for evaluating novel therapeutic strategies. To overcome the challenges in PKU animal model development, Protheragen leverages advanced technological platforms to create highly precise models that accelerate the candidate drug development pipeline from discovery to market approval.
Overview of Phenylketonuria (PKU) Animal Models
Animal models of phenylketonuria (PKU), primarily genetically engineered mice with mutations in the Pah gene, faithfully recapitulate the hyperphenylalaninemia and neurobehavioral impairments characteristic of the human disease. These models exhibit key pathological features including elevated blood phenylalanine levels, reduced serotonin and dopamine synthesis, and structural brain abnormalities. They serve as indispensable tools for investigating disease mechanisms related to neurotransmitter deficiencies and cognitive dysfunction, while also providing critical platforms for evaluating therapeutic strategies such as dietary management, enzyme replacement therapies, and novel gene-based interventions aimed at restoring metabolic and neurological function.
Fig.1 Pig models for the study of phenylketonuria (PKU). (Bobrova N A, et al., 2025)
Our Services
At Protheragen, we bridge the gap between research concept and clinical translation by providing genetically precise and phenotypically validated phenylketonuria (PKU) animal models. Our end-to-end service, from custom model generation via advanced gene editing to comprehensive phenotypic and efficacy analyses, is designed to deliver robust, data-driven preclinical studies that accelerate your therapeutic development pipeline.
Animal Models of Phenylketonuria (PKU)
Protheragen leverage a multi-species approach to advance phenylketonuria (PKU) research, providing a comprehensive portfolio of genetically engineered animal models. Our expertise extends beyond standard murine systems to include larger translational models like pigs, which more closely mimic human physiology, as well as high-throughput zebrafish platforms and innovative avian models.
- BTBR-Pahenu2/J Mice
- Pah-R261Q Mice
- B6.BTBR-Pahenu2/MalnJ Mice
- PAH-deficient Pig
- BTBR-Pahenu1/J Mice
- Qdpra Knockout Zebrafish
- B6(Cg)-Pahtm1.1(PAH*R408W)Xiwan/J Mice
- Qdprb1 Knockdown Zebrafish
- PAH P281L Mice
- PAH Knockout Chicken
- PAH-KO Mice
- Other Models
Featured Animal Models
| Model Name | Modeling Method | Detailed Description |
| Pah KO Mice | Knockout | Phenylalanine hydroxylase (PAH), a member of the biopterin-dependent aromatic amino acid hydroxylase family, is encoded by the PAH gene and catalyzes the hydroxylation of phenylalanine (Phe) to tyrosine (Tyr), a key step in Phe catabolism. Deficiency in PAH activity leads to autosomal recessive phenylketonuria (PKU), also known as PAH deficiency. Pah KO mice serve as a PKU disease model, completely lacking Pah mRNA and PAH protein expression, resulting in PKU-associated phenotypes, including impaired Phe metabolism. These mice exhibit progressive depigmentation as Phe concentrations increase and Tyr levels decrease in their blood. By 8 weeks of age, their coat color completely transforms to brown, reflecting the characteristic hypopigmentation phenotype associated with PKU pathology. |
| B6-Pah-R243Q Mice | Knock-in | The B6-Pah-R243Q mouse is a knock-in model that carries a prevalent human pathogenic point mutation (p.R243Q) in the Pah gene, faithfully replicating the hyperphenylalaninemia and metabolic characteristics of classical PKU. |
| Pts-flox Mice | Conditional Knockout | The Pts-flox mouse features critical exons of the Pts gene flanked by loxP sites, serving as a conditional-ready model that enables tissue- or time-specific gene deletion when crossed with Cre-driver lines. |
| Pts-KO Mice | Knockout | The Pts-KO mouse is a constitutive knockout model with a complete disruption of the Pts gene, resulting in severe hyperphenylalaninemia and typically embryonic lethality in the homozygous state, making it essential for studying early developmental mechanisms. |
Case Study-Pah-KO Mouse Model
Model Introduction
This case study details the generation and biochemical characterization of the Pah-KO mouse model for phenylketonuria (PKU). PKU is an inherited metabolic disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene, leading to impaired conversion of phenylalanine (Phe) to tyrosine (Tyr). Our model was engineered to carry a premature stop codon in the Pah gene, creating a genetically accurate platform for studying PKU pathophysiology and therapeutic development.
Methodology
- Animal Model: Pah-KO homozygous (Hom) and heterozygous (Het) mice on a C57BL/6J background.
- Modeling Method: The Pah-KO mouse model was generated by introducing a premature stop codon into the Pah gene exon 1 via gene editing in C57BL/6J fertilized eggs. Founder mice carrying the mutation were expanded, and a specific line was bred to establish heterozygous (Het) and homozygous (Hom) colonies.
- Validation Method: The homozygous knockout status was confirmed by genotyping via tail-biopsy PCR and the absence of Pah protein via Western blot.
- Phenotypic Analysis: Plasma levels of phenylalanine (Phe) and tyrosine (Tyr) were quantified using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).
Phenotypic Analysis & Results
Metabolic analysis confirmed that Hom mice recapitulate the characteristic biochemical profile of human PKU.
- Hyperphenylalaninemia: Plasma Phe levels in Hom mice were significantly elevated compared to Het controls (p < 0.0001), demonstrating the impaired phenylalanine metabolism characteristic of PKU (Fig.2A).
- Tyrosine Deficiency: Concurrently, plasma Tyr levels were significantly reduced in Hom mice compared to Het controls (p < 0.0001), confirming the disruption in the phenylalanine-to-tyrosine conversion pathway (Fig.2B).
- Classic PKU Biochemical Profile: The combination of markedly elevated Phe and reduced Tyr levels establishes this model as faithfully reproducing the core metabolic abnormality of human phenylketonuria.
Fig.2 Analysis of plasma amino acid levels in Pah-KO mice. (A) Blood phenylalanine (Phe) levels in homozygous (Hom) and heterozygous (Het) mice at multiple timepoints. (B) Blood tyrosine (Tyr) levels in Hom and Het mice at multiple timepoints. Data are presented as mean ± SD (Phe and Tyr levels in Hom vs Het mice p < 0.0001, n=7 mice/group).
Conclusion
This case study validates the Pah-KO mouse as a highly relevant model for phenylketonuria (PKU) research. The model demonstrates the hallmark metabolic disturbances of PKU, including severe hyperphenylalaninemia and concomitant tyrosine deficiency. This genetically precise knockout model provides an ideal platform for investigating PKU disease mechanisms and evaluating novel therapeutic approaches, including enzyme replacement therapies, gene therapies, and metabolic interventions.
Contact Us
Focusing on preclinical research, Protheragen utilizes precise animal models to enable pharmacodynamic (PD), pharmacokinetic (PK), and toxicology assessments to support the development and regulatory approval of potential therapies. If you are interested in our animal model development services, please do not hesitate to contact us for more details and quotation information.
Reference
- Bobrova N A, Lyubimova D I, Mishina D M, et al. Experimental Animal Models of Phenylketonuria: Pros and Cons[J]. International Journal of Molecular Sciences, 2025, 26(11): 5262.