A new imprinted gene cloned by a methylation-sensitive genome scanning method.
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ABSTRACT:
SUBMITTER: Hatada I
PROVIDER: S-EPMC310518 | biostudies-other | 1993 Dec
REPOSITORIES: biostudies-other
Publications
A new imprinted gene cloned by a methylation-sensitive genome scanning method.
Hatada I I Sugama T T Mukai T T
Nucleic acids research 19931201 24
We cloned a new imprinted gene by searching for parental-origin-specific CpG methylations using methylation-sensitive two-dimensional genome scanning method. This gene encodes a putative 51 kDa protein with significant similarity to U2 small nuclear ribonucleoprotein auxiliary factor small subunits, an essential mammalian splicing factor, and is located on mouse chromosome 11, of which maternal duplication/paternal deficiency results in a small body. ...[more]
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Project description:DNA methylation is a major epigenetic modification in the mammalian genome that regulates crucial aspects of gene function. Mammalian cloning by somatic cell nuclear transfer (SCNT) often results in gestational or neonatal failure with only a small proportion of manipulated embryos producing live births. Many of the embryos that survive to term later succumb to a variety of abnormalities that are likely due to inappropriate epigenetic reprogramming. Aberrant methylation patterns of imprinted genes in cloned cattle and mice have been elucidated, but few reports have analyzed the cloned pig genome. Four surviving cloned sows that were created by ear fibroblast nuclear transfer, each with a different life span and multiple organ defects, such as heart defects and bone growth delay, were used as epigenetic study materials. First, we identified four putative differential methylation regions (DMR) of imprinted genes in the wild-type pig genome, including two maternally imprinted loci (INS and IGF2) and two paternally imprinted loci (H19 and IGF2R). Aberrant DNA methylation, either hypermethylation or hypomethylation, commonly appeared in H19 (45% of imprinted loci hypermethylated vs. 30% hypomethylated), IGF2 (40% vs. 0%), INS (50% vs. 5%), and IGF2R (15% vs. 45%) in multiple tissues from these four cloned sows compared with wild-type pigs. Our data suggest that aberrant epigenetic modifications occur frequently in the genome of cloned swine. Even with successful production of cloned swine that avoid prenatal or postnatal death, the perturbation of methylation in imprinted genes still exists, which may be one of reason for their adult pathologies and short life. Understanding the aberrant pattern of gene imprinting would permit improvements in future cloning techniques.
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