Fxr1, also known as Fragile X mental retardation autosomal 1, is an RNA-binding protein belonging to the Fragile X-related (FXR) family. It is crucial for development and plays significant roles in multiple biological processes such as gene expression regulation. It is involved in pathways related to translation, cell shape regulation, and may be associated with various disease-related pathways [1,2]. Genetic models, especially KO/CKO mouse models, are valuable for studying its functions.

Germline-specific Fxr1 ablation in mice impaired the translation of target mRNAs, causing defective spermatid development and male infertility, indicating its essential role in spermiogenesis [1]. In another aspect, point mutations in Fxr1, similar to those in its homolog FMR1 causing fragile X syndrome, disrupted the Fxr1 network which is necessary for RhoA signaling-induced actomyosin reorganization, affecting cell shape, migration, and synaptic function [2].

In conclusion, Fxr1 is vital for processes like spermiogenesis and actomyosin remodeling. The study of Fxr1 through KO/CKO mouse models has provided insights into its role in male infertility and processes related to cell shape and function, which are relevant in understanding associated diseases.