Two MSCs lead cell-based therapy

EST and cDNA analysis in iPS cells and their parental cells

Recent advance of large sequencing technique enables allele-specific gene expression. If iPS cells represent ICM cells, such allele-specific gene expression pattern may be traced back from somatic cell type to ICM cell type.

Allele-specific methylation in the non-inprinted gene

K18 gene is methylated in an allele-specific manner in U937 myelomonocytic cells. Unimprinted genes may also have allele-specific methylation. This allele-specificity may not depend on parental sex.

Discussion
1. Allele specific methylation is maintained during hundreds of cell division or passage. This allele-specific methylation is probably maintained from the generation of the cell line. This indicates that maintenance of methylation is extremely precise.

2. De novo methylase activity is not present at all in the U-937 cells.
De novo methyltransferase activity is obviously present in ES cells. When the hK18 gene is transfected into ES cells, the enhancer of the gene gets methylated. Interestingly, ratio of methylation to non-methylation of the ETS site in exogenously transfected K18 gene is almost the same as that in the endogenous K18 gene.

3. Maintenance methylase activity is present or maybe strong in the cells.

4. Difference in methylation is thought to happen after each division. If these methylation status occurs during long range of cell cultures, pattern of methylation should be the same. However, methylation pattern is random in each cell. Furthermore, maintenance methylase made some mistakes in cells, or the amount of methylation gradually decreases.

5. I do not know what made allele-specific methylation, though.

農民のような力強さ

堀田先生が、昔、遺伝研の助教に対する面接でおっしゃった言葉だそうです。

Drosophilaの科学は、貴族である。完成され、美しい。でも、ほころびやすい。マウスは、農民の一揆のようだ。どろくさいが、次世代の力強さを備える。その次は分からない。

うううむ。当時の科学を分かりやすくしてくれているんだどうが、今でも通じる。実際に面接を受けた方に、ビールを飲んでいるときに聴いた。酔っていたのだろうか。感動してしまった。

アロ認証

造語です。研究室の者は、受精にこの言葉をあてている。精子と卵子の出会いにかかる現象に、この言葉をあてている。よく考えてみると生体において、アロ認識は分子レベルでも細胞レベルでも、至極当然の現象である。改めて、「アロ認識」と言われると新鮮な気分に聞こえる。