title: Identification of alternate splice variants for murine SmX5.
abstract: We report here the identification of three additional murine SmX5 alternative transcripts, designated SmX5a, b and c. The cDNA of SmX5a possesses intron 1 in its entirety, and SmX5b harbors a part of intron 2. The retained fragment of SmX5c starts at the same position as SmX5b, but the retention extends through the remaining portion of intron 2. The sequence of retained DNA at all the intron-exon boundaries conforms to the "GT-AG" rule. RT-PCR analysis indicates that the three isoforms are stable transcripts, all at low frequency when compared with SmX5. Expression analysis by RT-PCR indicates that SmX5 and its isoforms exist in murine brain, kidney, testis, thymus, liver, spleen and heart. The SmX5a isoform is predominantly expressed in the thymus, while SmX5b and c are expressed in all tissues examined. The presence of alternatively spliced SmX5 isoforms and tissue-specific variation in splicing patterns suggests that SmX5 expression is complex and that the regulation of all four SmX5 mRNA levels may be critical in maintaining proper pre-mRNA splicing machinery in different cell types.
authors.affiliation: Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Cheng
authors.forename: Nanthan D
authors.initials: ND
authors.lastname: Meeker
authors.forename: Cory
authors.initials: C
authors.lastname: Teuscher
authors.forename: Run-Lin
authors.initials: RL
authors.lastname: Ma
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005260:Female; D015870:Gene Expression; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; C108240:Lsm2 protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; D017411:Ribonucleoproteins, Small Nuclear