Diverse Cre recombinase expression pattern in Albumin-Cre driver rats.

Rats (Rattus norvegicus) have been widely utilized as model animals due to their physiological characteristics, making them suitable for surgical and long-term studies. They have played a crucial role in biomedical research, complementing studies conducted in mice. The advent of genome editing technologies has facilitated the generation of genetically modified rat strains, advancing studies in experimental animals.

CRISPR Diagnostics for Quantification and Rapid Diagnosis of Myotonic Dystrophy Type 1 Repeat Expansion Disorders.

Repeat expansion disorders, exemplified by myotonic dystrophy type 1 (DM1), present challenges in diagnostic quantification because of the variability and complexity of repeat lengths. Traditional diagnostic methods, including PCR and Southern blotting, exhibit limitations in sensitivity and specificity, necessitating the development of innovative approaches for precise and rapid diagnosis. Here, we introduce a CRISPR-based diagnostic method, REPLICA (peat-rimed ocating of nherited disease by s3), for the quantification and rapid diagnosis of DM1.

Genome editing using type I-E CRISPR-Cas3 in mice and rat zygotes.

The type I CRISPR system has recently emerged as a promising tool, especially for large-scale genomic modification, but its application to generate model animals by editing zygotes had not been established. In this study, we demonstrate genome editing in zygotes using the type I-E CRISPR-Cas3 system, which efficiently generates deletions of several thousand base pairs at targeted loci in mice with 40%-70% editing efficiency without off-target mutations. To overcome the difficulties associated with detecting the variable deletions, we used a newly long-read sequencing-based multiplex genotyping approach.

A novel Kit mutant rat enables hematopoietic stem cell engraftment without irradiation.

Hematopoietic stem cell (HSC) transplantation is extensively studied in mouse models, but their limited scale presents challenges for effective engraftment and comprehensive evaluations. Rats, owing to their larger size and anatomical similarity to humans, offer a promising alternative. In this study, we establish a rat model with the Kit mutation, mirroring Kit mice often used in KIT signaling and HSC research.

Thioredoxin deficiency increases oxidative stress and causes bilateral symmetrical degeneration in rat midbrain.

Thioredoxin, encoded by Txn1, acts as a critical antioxidant in the defense against oxidative stress by regulating the dithiol/disulfide balance of interacting proteins. The role of thioredoxin in the central nervous system (CNS) is largely unknown. A phenotype-driven study of N-ethyl-N-nitrosourea-mutated rats with wild-running seizures revealed the importance of Txn1 mutations in CNS degeneration.

A high-quality severe combined immunodeficiency (SCID) rat bioresource.

Immunodeficient animals are valuable models for the engraftment of exogenous tissues; they are widely used in many fields, including the creation of humanized animal models, as well as regenerative medicine and oncology. Compared with mice, laboratory rats have a larger body size and can more easily undergo transplantation of various tissues and organs. Considering the absence of high-quality resources of immunodeficient rats, we used the CRISPR/Cas9 genome editing system to knock out the interleukin-2 receptor gamma chain gene (Il2rg) in F344/Jcl rats-alone or together with recombination activating gene 2 (Rag2)-to create a high-quality bioresource that researchers can freely use: severe combined immunodeficiency (SCID) rats.

Novel animal model of combined generalized and focal epilepsy.

Thioredoxin, encoded by Txn1, is a critical antioxidant that protects against oxidative damage by regulating the dithiol/disulfide balance of interacting proteins. We recently discovered the Adem rat, an epileptic rat harboring the Txn1-F54L mutation, characterized by wild running and vacuolar degeneration in the midbrain. This study aimed to characterize the classification of epilepsy in Adem rats.

Dorsal telencephalon-specific Nprl2- and Nprl3-knockout mice: novel mouse models for GATORopathy.

The most frequent genetic cause of focal epilepsies is variations in the GAP activity toward RAGs 1 complex genes DEP domain containing 5 (DEPDC5), nitrogen permease regulator 2-like protein (NPRL2) and nitrogen permease regulator 3-like protein (NPRL3). Because these variations are frequent and associated with a broad spectrum of focal epilepsies, a unique pathology categorized as GATORopathy can be conceptualized. Animal models recapitulating the clinical features of patients are essential to decipher GATORopathy.

[DEPDC5, a new key to understand various epilepsies].

Epilepsy is one of the most frequent neurological disorders characterized by spontaneous and recurrent seizures. Most seizures last for the lifetime and the patients require long term therapies. However, about 30% of the patients are refractory to antiepileptic drugs.

Depdc5 knockdown causes mTOR-dependent motor hyperactivity in zebrafish.

Objective: was identified as a major genetic cause of focal epilepsy with deleterious mutations found in a wide range of inherited forms of focal epilepsy, associated with malformation of cortical development in certain cases. Identification of frameshift, truncation, and deletion mutations implicates haploinsufficiency of in the etiology of focal epilepsy. DEPDC5 is a component of the GATOR1 complex, acting as a negative regulator of mTOR signaling.

Novel GABRG2 mutations cause familial febrile seizures.

Objective: To identify the genetic cause in a large family with febrile seizures (FS) and temporal lobe epilepsy (TLE) and subsequently search for additional mutations in a cohort of 107 families with FS, with or without epilepsy.

Methods: The cohort consisted of 1 large family with FS and TLE, 64 smaller French families recruited through a national French campaign, and 43 Italian families. Molecular analyses consisted of whole-exome sequencing and mutational screening.

Depdc5 knockout rat: A novel model of mTORopathy.

DEP-domain containing 5 (DEPDC5), encoding a repressor of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway, has recently emerged as a major gene mutated in familial focal epilepsies and focal cortical dysplasia. Here we established a global knockout rat using TALEN technology to investigate in vivo the impact of Depdc5-deficiency. Homozygous Depdc5(-/-) embryos died from embryonic day 14.

Familial focal epilepsy with focal cortical dysplasia due to DEPDC5 mutations.

Objective: The DEPDC5 (DEP domain-containing protein 5) gene, encoding a repressor of the mTORC1 signaling pathway, has recently emerged as a major gene mutated in familial focal epilepsies. We aimed to further extend the role of DEPDC5 to focal cortical dysplasias (FCDs).

Methods: Seven patients from 4 families with DEPDC5 mutations and focal epilepsy associated with FCD were recruited and investigated at the clinical, neuroimaging, and histopathological levels.

Glutamatergic neuron-targeted loss of LGI1 epilepsy gene results in seizures.

Leucin-rich, glioma inactivated 1 (LGI1) is a secreted protein linked to human seizures of both genetic and autoimmune aetiology. Mutations in the LGI1 gene are responsible for autosomal dominant temporal lobe epilepsy with auditory features, whereas LGI1 autoantibodies are involved in limbic encephalitis, an acquired epileptic disorder associated with cognitive impairment. We and others previously reported that Lgi1-deficient mice have early-onset spontaneous seizures leading to premature death at 2-3 weeks of age.

DEPDC5 mutations in families presenting as autosomal dominant nocturnal frontal lobe epilepsy.

Objective: To study the prevalence of DEPDC5 mutations in a series of 30 small European families with a phenotype compatible with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE).

Methods: Thirty unrelated families referred with ADNFLE were recruited in France, Italy, Germany, Belgium, and Norway. Whole-exome sequencing was performed in 10 probands and direct sequencing of the DEPDC5 coding sequence in 20 probands.

Evaluation of seizure foci and genes in the Lgi1(L385R/+) mutant rat.

Mutations in the leucine-rich, glioma inactivated 1 (LGI1) gene have been identified in patients with autosomal dominant lateral temporal lobe epilepsy (ADLTE). We previously reported that Lgi1 mutant rats, carrying a missense mutation (L385R) generated by gene-driven N-ethyl-N-nitrosourea (ENU) mutagenesis, showed generalized tonic-clonic seizures (GTCS) in response to acoustic stimuli. In the present study, we assessed clinically relevant features of Lgi1 heterozygous mutant rats (Lgi1(L385R/+)) as an animal model of ADLTE.

Mutations of DEPDC5 cause autosomal dominant focal epilepsies.

The main familial focal epilepsies are autosomal dominant nocturnal frontal lobe epilepsy, familial temporal lobe epilepsy and familial focal epilepsy with variable foci. A frameshift mutation in the DEPDC5 gene (encoding DEP domain-containing protein 5) was identified in a family with focal epilepsy with variable foci by linkage analysis and exome sequencing. Subsequent pyrosequencing of DEPDC5 in a cohort of 15 additional families with focal epilepsies identified 4 nonsense mutations and 1 missense mutation.

Generation and characterization of severe combined immunodeficiency rats.

Severe combined immunodeficiency (SCID) mice, the most widely used animal model of DNA-PKcs (Prkdc) deficiency, have contributed enormously to our understanding of immunodeficiency, lymphocyte development, and DNA-repair mechanisms, and they are ideal hosts for allogeneic and xenogeneic tissue transplantation. Here, we use zinc-finger nucleases to generate rats that lack either the Prkdc gene (SCID) or the Prkdc and Il2rg genes (referred to as F344-scid gamma [FSG] rats). SCID rats show several phenotypic differences from SCID mice, including growth retardation, premature senescence, and a more severe immunodeficiency without "leaky" phenotypes.

A rat model for LGI1-related epilepsies.

Mutations of the leucine-rich glioma-inactivated 1 (LGI1) gene cause an autosomal dominant partial epilepsy with auditory features also known as autosomal-dominant lateral temporal lobe epilepsy. LGI1 is also the main antigen present in sera and cerebrospinal fluids of patients with limbic encephalitis and seizures, highlighting its importance in a spectrum of epileptic disorders. LGI1 encodes a neuronal secreted protein, whose brain function is still poorly understood.

Kcna1-mutant rats dominantly display myokymia, neuromyotonia and spontaneous epileptic seizures.

Mutations in the KCNA1 gene, which encodes for the α subunit of the voltage-gated potassium channel Kv1.1, cause episodic ataxia type 1 (EA1). EA1 is a dominant human neurological disorder characterized by variable phenotypes of brief episodes of ataxia, myokymia, neuromyotonia, and associated epilepsy.

Protective effect of humus extract against Trypanosoma brucei infection in mice.

Humic substances are formed during the decomposition of organic matter in humus, and are found in many natural environments in which organic materials and microorganisms are present. Oral administration of humus extract to mice successfully induced effective protection against experimental challenge by the two subspecies, Trypanosoma brucei brucei and T. brucei gambiense.