Identification of three mouse mu-opioid receptor (MOR) gene (Oprm1) splice variants containing a newly identified alternatively spliced exon.
The mouse mu-opioid receptor gene, Oprm1, is recognized currently to contain 17 alternatively spliced exons that generate 24 splice variants encoding at least 11 morphine-binding isoforms of the receptor. Here, we identify three new MOR splice variants that contain a previously undescribed exon, exon 18, and provide evidence that they are expressed in two mouse strains. The transcripts containing the newly identified exon 18 encode two new putative mu-opioid receptor isoforms, MOR-1V and MOR-1W. In mouse Oprm1, exon 18 is located between the described exons 10 and 6. Exon 18 appears to be conserved in the rat genome between exons 4 and 7. A BLAST search of the non-redundant GenBank database suggests that human OPRM1 may also contain exon 18. Analysis of mouse brain mRNA by RT-PCR suggests that MOR-1Vii transcripts are expressed in all areas of the brain analyzed, whereas expression of MOR-1Vi transcripts was restricted to thalamus and striatum. MOR-1W transcripts are expressed most highly in the hypothalamus, thalamus and striatum. In summary, we have identified three brain expressed, alternatively spliced mouse MOR splice variants containing a novel exon and encoding new putative MOR isoforms, MOR-1V and MOR-1W.
Doyle
Glenn A
GA
The Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States. e_gad@verizon.net
Rebecca Sheng
X
X
Lin
Sharon S J
SS
Press
Danielle M
DM
Grice
Dorothy E
DE
Buono
Russell J
RJ
Ferraro
Thomas N
TN
Berrettini
Wade H
WH
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D005091:Exons / Q000235:genetics*; D015870:Gene Expression; D008297:Male; D051379:Mice / Q000235:genetics*; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010766:Phosphorylation; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D018076:DNA, Complementary; C404943:Oprm protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; D017450:Receptors, Opioid, mu