title: The expression of PLP/DM-20 mRNA is restricted to the oligodendrocyte-lineage cells in the adult rat spinal cord.
abstract: Proteolipid protein (PLP) is the major component of myelin; its gene encodes two major splicing variants: PLP and DM-20. Compared with PLP, DM-20 lacks the amino acids encoded by exon IIIb. The expression of PLP/DM-20 in cells outside the oligodendrocyte-lineage is unclear. To address this issue, we analyzed the detailed expression pattern of PLP/DM-20 mRNA in the adult rat spinal cord by in situ hybridization (ISH) with a cRNA probe complementary to DM-20 mRNA, which has been used to detect both PLP and DM-20 both mRNA. ISH did not label the cells expressing NeuN nor glial fibrillary acidic protein but detected those expressing Olig2, indicating that PLP/DM-20 mRNA are expressed only in oligodendrocyte-lineage cells. This cell population was expected to contain NG2-expressing oligodendrocyte precursor cells (OPCs), because some exhibited the expression of glutathione S-transferase pi isoform in the nucleus. A recent publication showed that OPCs express PLP but not DM-20 mRNA. However, no OPCs were detected. We performed ISH with a cRNA probe that specifically recognizes PLP mRNA to successfully detect some OPCs. Additionally, OPCs were detected by ISH with a cRNA probe complementary to DM-20 mRNA that was digested via alkaline hydrolysis prior to ISH. These findings collectively demonstrate that PLP and DM-20 mRNA expression is restricted to oligodendrocyte-lineage cells, and imply that the undigested cRNA probe complementary to the full-length DM-20 mRNA sequence only recognizes DM-20 mRNA and not the PLP counterpart when applied to ISH without denaturation/digestion methods.
authors.affiliation: Department of Stem Cell Biology and Histology, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.|Faculty of Medicine, Tohoku University, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Takeda
authors.affiliation: Department of Stem Cell Biology and Histology, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Dezawa
authors.affiliation: Department of Stem Cell Biology and Histology, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan. Masaaki.Kitada@gmail.com.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kitada
mesh_terms: D000818:Animals; D019070:Cell Lineage / Q000235:genetics; D017403:In Situ Hybridization; D008297:Male; D018991:Myelin Proteolipid Protein / Q000235:genetics*; D009836:Oligodendroglia / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000166:cytology*
chemical_list: D018991:Myelin Proteolipid Protein; C489071:Plp1 protein, rat; D012333:RNA, Messenger
keywords: DM-20; Immunohistochemistry; In situ hybridization; Oligodendrocyte differentiation; Oligodendrocyte precursor cells; Proteolipid protein