title: Alternatively spliced products lacking exon 12 dominate the expression of fragile X mental retardation 1 gene in human tissues.
abstract: Fragile X mental retardation 1 gene (FMR1) expression is associated with fragile X syndrome (FXS) and exhibits several splicing products. However, the proportion of spliced isoforms that are expressed in different tissues remains unclear. In the present study, long-chain reverse transcription-polymerase chain reaction with a T cloning-sequencing method was conducted in order to analyze the entire coding region of the FMR1 gene in human tissues. In particular, FXS-associated tissues were analyzed, including the brain and testis. Twenty alternatively spliced isoforms were observed among 271 recombinants, including six novel ones. The isoform that consisted of the entire FMR1 coding region (ISO1) accounted for a small proportion of all isoforms. Isoforms lacking exon 12 were the most abundant. In particular, spliced isoforms ISO7 and ISO17 were the most abundant. However, their relative abundance varied between the peripheral blood cells, and the testis and brain tissues. Bioinformatic analyses suggested that exon 12 may be the sole exon undergoing positive selection. The results of the present study suggested that the mechanisms underlying alternative splicing (AS) of the FMR1 gene may be more complex. Furthermore, the functions of alternatively spliced products lacking exon 12 require further investigation. The results of the present study provide novel insights into the association between AS and the structure and function of the FMR1 gene.
authors.affiliation: Department of Pathology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian 350004, P.R. China.
authors.forename: Xianguo
authors.initials: X
authors.lastname: Fu
authors.affiliation: Department of Clinical Genetics and Experimental Medicine, Fuzhou General Hospital/Clinical College of Fujian Medical University, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Dezhu
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Department of Clinical Genetics and Experimental Medicine, Fuzhou General Hospital/Clinical College of Fujian Medical University, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Liao
authors.affiliation: Department of Clinical Genetics and Experimental Medicine, Fuzhou General Hospital/Clinical College of Fujian Medical University, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Qingqin
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Clinical Genetics and Experimental Medicine, Fuzhou General Hospital/Clinical College of Fujian Medical University, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Clinical Genetics and Experimental Medicine, Fuzhou General Hospital/Clinical College of Fujian Medical University, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Duo
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Clinical Genetics and Experimental Medicine, Fuzhou General Hospital/Clinical College of Fujian Medical University, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Aizhen
authors.initials: A
authors.lastname: Yan
authors.affiliation: Department of Clinical Genetics and Experimental Medicine, Fuzhou General Hospital/Clinical College of Fujian Medical University, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Fenghua
authors.initials: F
authors.lastname: Lan
mesh_terms: D017398:Alternative Splicing; D019143:Evolution, Molecular; D005091:Exons; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D005600:Fragile X Syndrome / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D020033:Protein Isoforms / Q000235:genetics
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; D020033:Protein Isoforms