Sf3b2-flox Mouse

SF3B2, a component of the U2 small nuclear ribonucleoprotein complex, plays a crucial role in RNA splicing. It is involved in regulating the splicing of target genes, which impacts various biological processes. The gene's function is significant in development, cell viability, and disease-related pathways [1,2,3,4,5,6]. Genetic models, such as gene knockout in different organisms, are valuable for studying its function.

Loss-of-function variants in SF3B2 have been identified as a prevalent genetic cause of craniofacial microsomia (CFM). In Xenopus, targeted morpholino knockdown of SF3B2 disrupts cranial neural crest precursor formation and leads to craniofacial cartilage defects [1]. In zebrafish, sf3b2-null mutants exhibit severe deficiencies in craniofacial cartilage and bone progenitors due to elevated apoptosis and reduced proliferation of cranial neural crest cells. RNA sequencing of these mutants reveals widespread disruption of mRNA splicing [9].

In human prostate cancer, SF3B2 is a critical determinant of androgen receptor splice variant-7 (AR-V7) expression, driving aggressive phenotypes, and its inhibition suppresses tumor growth [2]. In multiple sclerosis models, downregulation of SF3B2 preserves retinal ganglion cell survival and axonal integrity, and knockdown suppresses injury-response and necroptosis genes [3].

In addition, in mice, Prmt9 knockout, which affects the methylation of SF3B2, causes alternative splicing of many genes and abnormal synapse development [4]. In colorectal cancer, RNF6 promotes carcinogenesis by transcriptionally activating SF3B2, and targeting the RNF6-SF3B2 axis suppresses tumor growth [5]. In head and neck squamous cell carcinoma, SF3B2 binds to gene regulatory elements and mRNA to modulate transcription and RNA stability, promoting tumor growth [6].

A patient with a loss-of-function variant in SF3B2 presented with Hirschsprung disease and a complex cardiac defect without craniofacial features, expanding the phenotypic spectrum of SF3B2-related diseases [7]. Also, PGC1/PPAR drives cardiomyocyte maturation via SF3B2 [8].

In conclusion, SF3B2 is essential for RNA splicing and significantly impacts various biological processes. Model-based research, especially KO/CKO mouse models and other loss-of-function experiments in different organisms, has revealed its roles in diseases like CFM, prostate cancer, multiple sclerosis, abnormal synapse development, colorectal cancer, head and neck squamous cell carcinoma, Hirschsprung disease, and cardiac development. Understanding SF3B2's function provides insights into disease mechanisms and potential therapeutic targets.