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BMC Biology Dec 2020Zebrafish is a model organism widely used for the understanding of gene function, including the fundamental basis of human disease, enabled by the presence in its genome...
BACKGROUND
Zebrafish is a model organism widely used for the understanding of gene function, including the fundamental basis of human disease, enabled by the presence in its genome of a high number of orthologs to human genes. CRISPR/Cas9 and next-generation gene-editing techniques using cytidine deaminase fused with Cas9 nickase provide fast and efficient tools able to induce sequence-specific single base mutations in various organisms and have also been used to generate genetically modified zebrafish for modeling pathogenic mutations. However, the editing efficiency in zebrafish of currently available base editors is lower than other model organisms, frequently inducing indel formation, which limits the applicability of these tools and calls for the search of more accurate and efficient editors.
RESULTS
Here, we generated a new base editor (zAncBE4max) with a length of 5560 bp following a strategy based on the optimization of codon preference in zebrafish. Our new editor effectively created C-to-T base substitution while maintaining a high product purity at multiple target sites. Moreover, zAncBE4max successfully generated the Twist2 p.E78K mutation in zebrafish, recapitulating pathological features of human ablepharon macrostomia syndrome (AMS).
CONCLUSIONS
Overall, the zAncBE4max system provides a promising tool to perform efficient base editing in zebrafish and enhances its capacity to precisely model human diseases.
Topics: Abnormalities, Multiple; Animals; Base Sequence; Eye Abnormalities; Gene Editing; Humans; Macrostomia; Mutation; Zebrafish
PubMed: 33272268
DOI: 10.1186/s12915-020-00923-z -
Clinical & Experimental Optometry May 2021
Topics: Abnormalities, Multiple; Eye Abnormalities; Humans; Macrostomia
PubMed: 33689605
DOI: 10.1080/08164622.2021.1878839 -
BMC Pulmonary Medicine Aug 2019Ablepharon macrostomia syndrome (AMS) is a rare congenital malformation disorder caused by the autosomal-dominant mutations in gene TWIST2. Patients affected by the...
BACKGROUND
Ablepharon macrostomia syndrome (AMS) is a rare congenital malformation disorder caused by the autosomal-dominant mutations in gene TWIST2. Patients affected by the disease present abnormalities in ectoderm-derived structures mainly consisting in major facial dysmorphic features and rarely in visceral anomalies. The only laryngo-tracheal defect reported is malacia, with no reference to any anatomical stenosis. We describe a unique case of laryngo-tracheal stenosis in a woman, with genetically confirmed AMS currently followed at our Department.
CASE PRESENTATION
A 37-year-old Caucasian woman was admitted to the intensive care unit for acute dyspnea that required orotracheal intubation followed by tracheostomy. The bronchoscopy revealed abnormal tracheal tissue at the level of the cricoid and the first three tracheal rings reducing airway caliber by 80% (grade III according to the Cotton-Meyer classification). Treatment of the stenosis by means of temporary tracheostomy and corticosteroids therapy resulted in airway patency restoration and patient's return to her normal activities. Bronchoscopy at four and five months showed disappearance of the abnormal tissue and a residual anatomical laryngo-tracheal stenosis of about 20% (grade I according to the Cotton-Meyer classification) of the normal airway caliber.
CONCLUSIONS
To our knowledge, this is the first patient affected by AMS presenting with laryngo-tracheal stenosis.
Topics: Abnormalities, Multiple; Adrenal Cortex Hormones; Adult; Dyspnea; Eye Abnormalities; Female; Humans; Intubation, Intratracheal; Macrostomia; Mutation; Trachea; Tracheal Stenosis; Tracheostomy
PubMed: 31462237
DOI: 10.1186/s12890-019-0921-8