Ube3a KO Mice

Catalog Number: C001611

Strain Name: C57BL/6NCya-Ube3aem1/Cya

Genetic Background: C57BL/6NCya

Reproduction: Positive Female Mice x Wild-type Male Mice

 

Strain Description

The UBE3A gene encodes ubiquitin-protein ligase E3A, a critical enzyme in the ubiquitin-proteasome degradation system responsible for catalyzing substrate ubiquitination and regulating proteasomal clearance. This process is indispensable for maintaining proteostasis, particularly in neurons, where UBE3A governs synaptic plasticity, neural signaling, and neurodevelopment by modulating the levels of specific substrates. As an imprinted gene, UBE3A exhibits parent-of-origin-specific expression in brain neurons. The paternal allele is epigenetically silenced via cis-acting repression by a long noncoding antisense transcript (UBE3A-ATS) [1]. Consequently, only the maternal UBE3A allele is functionally active in neuronal populations. Loss of maternal UBE3A function disrupts ubiquitin-mediated proteolysis, leading to aberrant accumulation of neurodevelopmental regulators and subsequent dysregulation of synaptic maturation and circuit formation. These molecular deficits underlie the pathogenesis of Angelman syndrome (AS), a severe neurogenetic disorder. Patients with Angelman Syndrome commonly exhibit severe motor and intellectual developmental delays, ataxia, hypotonia, epilepsy, speech impairment, and distinctive facial features [2].

Currently, there is no curative treatment for Angelman Syndrome. Management primarily focuses on comprehensive rehabilitation aimed at alleviating symptoms and improving quality of life. Therapeutic development is centered on long-acting, precisely targeted, and safe approaches. Some therapies have entered clinical trial stages, mainly including: gene therapy (UBE3A gene supplementation via viral vectors), paternal UBE3A gene reactivation (utilizing ASOs, Targeted Gene Editing, etc., to target silencing long noncoding RNAs and unsilencing the gene), pathway intervention (such as OV101 to modulate neuronal over-inhibition), and symptomatic treatment (such as optimizing anti-epileptic drugs) [3-4].

Mice and humans share a high degree of similarity in the UBE3A gene region, and paternal imprinting of the Ube3a gene also exists in mice [5-6]. Studies have shown that knocking out the maternal Ube3a allele in mice also leads to phenotypes similar to human Angelman Syndrome (AS), including motor deficits, cognitive impairment, epilepsy susceptibility, sleep disturbances, and anxiety-like behaviors. Therefore, these mice are widely used in disease research, gene therapy evaluation, drug screening, and early intervention studies [5-6]. The Ube3a KO mouse is a gene knockout (KO) model, generated using gene editing technology to knock out the protein-coding sequence of the Ube3a gene (the homologous gene of human UBE3A gene) in mice. Preliminary behavioral data indicate that this model exhibits anxiety-like/compulsive behaviors, abnormal stress responses, and is accompanied by decreased spontaneous activity, shortened movement distance, and reduced average motility, among other motor function and behavioral abnormalities. It can be used for research on the pathogenesis of Angelman Syndrome (AS) and the development of related therapies.

Strain Strategy

The Ube3a gene in mice consists of 13 exons, with the start codon located in exon 3 and the stop codon in exon 13. This strain was created by knocking out the exon 6 using gene editing technology.


Application

  • Research on the pathogenic mechanisms and therapeutic drugs of Angelman Syndrome (AS);
  • Other neurological system studies.

Validation data

1. RT-qPCR

Figure 1. Gene expression in brain tissues of 3-week-old heterozygous male Ube3a KO mice and wild-type (WT) mice (n=3)*. The results show that compared to WT, the cerebellum, cerebral cortex, and hippocampus of maternally inherited heterozygous Ube3a KO mice achieved over 90% knockout efficiency, consistent with the characteristics of an imprinted gene.


*Note: The Ube3a KO mice used for validation data in this specification were generated by crossing heterozygous female Ube3a KO mice with wild-type male mice to obtain heterozygous male Ube3a KO mice. These heterozygous male mice mimic the primary pathogenic mechanism of human Angelman syndrome, namely paternal allele silencing and maternal allele expression deficiency in brain neurons.

2. Marble Burying

Figure 2. Marble Burying scores of 8-week-old heterozygous male Ube3a KO mice and wild-type (WT) mice (n=8). The results show that the Marble Burying scores of Ube3a KO heterozygous mice were significantly lower than those of WT mice, indicating that Ube3a KO mice exhibit lower anxiety-like or compulsive behavior and reduced activity.

3. Nest building

Figure 3. Nest building scores of 8-week-old heterozygous male Ube3a KO mice and wild-type (WT) mice (n=8). The results show that compared to WT mice, Ube3a KO mice exhibited a significant decline in nest-building behavior and demonstrated reduced activity.

4. Open Field

Figure 4. Open Field test of 9-week-old heterozygous male Ube3a KO mice and wild-type (WT) mice (n=8). The results show that compared to WT mice, Ube3a KO mice exhibited a significant decline in activity, total distance, and mean velocity, demonstrating reduced overall activity. Some Ube3a KO mice also displayed obvious stress abnormalities, such as jumping and agitation when the cage was opened, similar to seizure-like behavior.

5. Rotarod Test

Figure 5. Rotarod test results of 8-week-old heterozygous male Ube3a KO mice and wild-type (WT) mice (n=8). The results show that, compared to WT mice, Ube3a KO mice exhibited no significant differences in speed and latency to fall.


References
[1]Krzeski JC, Judson MC, Philpot BD. Neuronal UBE3A substrates hold therapeutic potential for Angelman syndrome. Curr Opin Neurobiol. 2024 Oct;88:102899.
[2]Buiting K, Williams C, Horsthemke B. Angelman syndrome - insights into a rare neurogenetic disorder. Nat Rev Neurol. 2016 Oct;12(10):584-93.
[3]Elgersma Y, Sonzogni M. UBE3A reinstatement as a disease-modifying therapy for Angelman syndrome. Dev Med Child Neurol. 2021 Jul;63(7):802-807.
[4]Keary CJ, McDougle CJ. Current and emerging treatment options for Angelman syndrome. Expert Rev Neurother. 2023 Jul-Dec;23(9):835-844.
[5]Jiang YH, Armstrong D, Albrecht U, Atkins CM, Noebels JL, Eichele G, Sweatt JD, Beaudet AL. Mutation of the Angelman ubiquitin ligase in mice causes increased cytoplasmic p53 and deficits of contextual learning and long-term potentiation. Neuron. 1998 Oct;21(4):799-811.
[6]Rotaru DC, Mientjes EJ, Elgersma Y. Angelman Syndrome: From Mouse Models to Therapy. Neuroscience. 2020 Oct 1;445:172-189.