如果能夠通過基因調(diào)控使蠶吐出各種顏色的蠶絲,，那么我們還需要給絲綢染色干什么呢,。
這是日本東京大學(xué)的科學(xué)及們的目標(biāo)，他們希望能夠通過基因工程讓蠶吐出指定顏色的蠶絲,。他們的結(jié)果發(fā)表在最新的《Proceedings of the National Academy of Sciences of the United States》上,。
文章的第一作者，東京大學(xué)的Takashi Sakudoh說：“對蠶的色素傳輸系統(tǒng)的了解,，使得我們有可能通過基因調(diào)控來控制蠶絲的顏色和色素比例,。”
自然界中，蠶繭的顏色有白色,、黃色,、稻草色,、橙紅色、粉紅色和綠色,。絲綢的顏色來自于桑蠶吃桑樹葉時對自然色素的吸收,。
日本的科學(xué)家們發(fā)現(xiàn)吐白色絲的蠶的Y基因產(chǎn)生了變異。DNA的片斷被刪除了,。而Y基因會使桑蠶能夠吸收桑樹葉中的類胡蘿卜素——一種黃色的化學(xué)物質(zhì),。
科學(xué)家們發(fā)現(xiàn)這些變異的蠶會產(chǎn)生沒有功能的類胡蘿卜素捆綁蛋白（CBP）——一種已知會輔助色素吸收的蛋白。
因此,，研究人員通過基因工程技術(shù)把原始的Y基因引入變異的蠶,，這些蠶會產(chǎn)生有功能的CBP，于是就吐出了黃色的蠶絲,。并且在多輪雜交后,，蠶絲的黃色會更加地鮮艷。
日本科學(xué)家的初步研究結(jié)果掌握了黃色蠶絲的控制方法,，相信隨著研究的深入,，當(dāng)人們掌握了控制多種顏色的方法后，我們的絲綢就不再需要染色了,。
原文鏈接：http://www.physorg.com/news97810726.html
劉樂譯自：physorg.com
原始出處:
Published online before print March 19, 2007, 10.1073/pnas.0701331104
PNAS | March 27, 2007 | vol. 104 | no. 13 | 5668-5673
Wnt/-catenin/CBP signaling maintains long-term murine embryonic stem cell pluripotency
Tomoyuki Miyabayashi*,, Jia-Ling Teo,, Masashi Yamamoto*, Michael McMillan,, Cu Nguyen,, and Michael Kahn,,,¶
*Central R&D Laboratories, Asahi Kasei Corporation, Shizuoka 416-8501, Japan; Institute for Chemical Genomics, 600 Broadway, Suite 580, Seattle, WA 98122; and ¶Department of Pharmacology, University of Washington, Seattle, WA 98195
Communicated by Edwin G. Krebs, University of Washington School of Medicine, Seattle, WA, February 14, 2007 (received for review October 23, 2006)
Abstract
Embryonic stem cells (ESCs) represent an important research tool and a potential resource for regenerative medicine. Generally, ESCs are cocultured with a supportive feeder cell layer of murine embryonic fibroblasts, which maintain the ESCs' capacity for self-renewal and block spontaneous differentiation. These cumbersome conditions, as well as the risk of xenobiotic contamination of human ESCs grown on murine embryonic fibroblasts, make it a priority to develop chemically defined methods that can be safely used for the expansion of ESCs. Using a high-throughput, cell-based assay, we identified the small molecule IQ-1 that allows for the Wnt/-catenin-driven long-term expansion of mouse ESCs and prevents spontaneous differentiation. We demonstrate that IQ-1, by targeting the PR72/130 subunit of the serine/threonine phosphatase PP2A, prevents -catenin from switching coactivator usage from CBP to p300. The increase in -catenin/CBP-mediated transcription at the expense of -catenin/p300-mediated transcription is critical for the maintenance of murine stem cell pluripotency.
p300 | PP2A | Wnt signaling | Nkd | small molecule
