Efficient derivation and banking of clinical-grade human embryonic stem cell lines in accordance with Japanese regulations

[Introduction] We recently established clinical-grade human embryonic stem cell (hESC) line KthES11 in accordance with current good manufacturing practice standards in Japan. Despite this success, the establishment efficiency was very low at 7.1% in the first period. [Methods] To establish clinical-grade hESC lines, we used xeno-free chemically defined medium StemFit AK03N with the LM-E8 fragments instead of feeder cells. The protocol was then optimized, especially in the early culture phase. [Results] We established five hESC lines (KthES12, KthES13, KthES14, KthES15, and KthES16) with 45.5% efficiency. All five hESC lines showed typical hESC-like morphology, a normal karyotype, pluripotent state, and differentiation potential for all three germ layers. Furthermore, we developed efficient procedures to prepare master cell stocks for clinical-grade hESC lines and an efficient strategy for quality control testing. [Conclusions] Our master cell stocks of hESC lines may contribute to therapeutic applications using human pluripotent stem cells in Japan and other countries

北半球冬季の大気大循環と日本周辺の海面水温が日本の気温に与える影響

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木）　国立極地研究所１階交流アトリウ

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Trends in the Summer Northern Annular Mode and Arctic Sea Ice

The summer Arctic sea ice extent (SIE) during the period 1996-2008 had an accelerating trend of retreat. The difference of SIE between May and September has a significant correlation with the summer Northern Hemisphere Annular Mode (summer NAM). The summer NAM had a significant positive trend during the period 1958-1996, and a weak negative trend during the period 1996-2008. The atmospheric circulation during the recent period had a trend of anticyclonic circulation over the Arctic with easterly wind over the marginal seas. In addition, tropospheric warming was enhanced especially over the Arctic and near the ground surface

Trends in the Summer Northern Annular Mode and Arctic Sea Ice

The summer Arctic sea ice extent (SIE) during the period 1996−2008 had an accelerating trend of retreat. The difference of SIE between May and September has a significant correlation with the summer Northern Hemisphere Annular Mode (summer NAM). The summer NAM had a significant positive trend during the period 1958−1996, and a weak negative trend during the period 1996−2008. The atmospheric circulation during the recent period had a trend of anticyclonic circulation over the Arctic with easterly wind over the marginal seas. In addition, tropospheric warming was enhanced especially over the Arctic and near the ground surface. 1

Recent Breakdown of the Seasonal Linkage between the Winter North Atlantic Oscillation/Northern Annular Mode and Summer Northern Annular Mode

The summer northern annular mode (NAM) and the winter North Atlantic Oscillation (NAO)/winter NAM have a positive correlation from the mid-1960s to the 1980s. Namely, when the winter NAO/NAM is in a positive phase, the following summer NAM tended to be in a positive phase. During the period from the mid-1960s to the 1980s, the NAO/NAM signals extended to the stratosphere in winter. Also, the lower-tropospheric warm anomaly over northern Eurasia in winter associated with the positive phase of NAO/NAM continued into spring. In summer, the annular anomalies in the temperature and 500-hPa height fields appeared, and the high-latitude westerly wind was enhanced following the winter positive NAO/NAM. However, after circa 1990, the seasonal linkage was broken (i.e., the winter-to-summer correlation became insignificant). The stratospheric signal in the winter NAO/NAM became weak and summer signals associated with the winter NAO/NAM almost disappeared. Seasonal evolutions of atmospheric circulation and sea surface temperature (SST) anomalies associated with the winter NAO are examined for an early good-linkage period and a recent poor-linkage period. We discuss the possible causes of the linkage breakdown such as stratospheric ozone, North Atlantic SST, and Atlantic multidecadal oscillation, besides chaotic internal variability in the climate system. Simulations with the Community Earth System Model suggest that the ocean and/or sea ice with interseasonal memories possibly cause the linkage, besides large internal variability through which the linkage can take place by chance