Identification of genetic and epigenetic similarities of SPHK1/Sphk1 in mammals.
In normal tissues, methylation of CpG islands is generally accepted to be limited to the inactive X-chromosome and imprinting clusters. Gene Sphk1 has shown complex organization, indicated by multiple alternative splicing and tissue-dependent DNA methylation within the limited area (T-DMR) of the CpG island in the rat. Comparisons among human, mouse and rat SPHK1/Sphk1 genomic DNA revealed five coding exons and association of a CpG island at the 5' end in common. We also found two novel subtypes, for a total of eight mRNA subtypes generated through selective usage of untranslated first exons. A 38-bp region at the 5'-end of T-DMR is highly conserved. This restricted area is specifically hypomethylated in the brain. Here, we examine the complex genetic/epigenetic features of the SPHK1/Sphk1 CpG island, and suggest that the T-DMR is the core target for tissue-dependent CpG island methylation.
Imamura
Takuya
T
Laboratory of Cellular Biochemistry, Animal Resource Sciences, Veterinary Medical Sciences, The University of Tokyo, Japan.
Miyauchi-Senda
Nanami
N
Tanaka
Satoshi
S
Shiota
Kunio
K
D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D018899:CpG Islands / Q000235:genetics; D004247:DNA / Q000032:analysis; D019175:DNA Methylation; D019143:Evolution, Molecular; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D000099157:Sphingosine Kinase
D004247:DNA; D017853:Phosphotransferases (Alcohol Group Acceptor); D012333:RNA, Messenger; D000099157:Sphingosine Kinase