Report 14-04-07

Lab work done.
Continue the reading...

Todo 14-04-07

Digest and ligate.
Read the data for the 3rd lab placement.
Shopping.

两个作者

阿纳托尔·法朗士（Anatole France，1844-1924）
南茜·埃特考夫

我老婆可能会喜欢他们的书

录梦一则

前日偶得一梦，吾乃少梦之人，故记之。
吾梦中之衣冠不可考，然他人著白褂、口罩，度己衣亦同。吾身于某所，内似坑道，洞外有篷，事材料研究。吾业者，借核子炸弹之助，锻金于地下也。其弹形似莫洛托夫鸡尾酒，耗三弹于一功，金成。

Report 13-04-07

PCR products were purified.
All flies in collection bottles were dead.
Submitted the draft.
Almost finished the reading of "Why is sex fun?...", some good ideas, however a big portion is just common knowledge. -- yes, may be every man needs a phallocarp...

Todo 13-04-07

Plan the slides, and poster.
Make model graph for introduction.
Cloning.
Submit the figures and updated report.

Report 12-04-07

Hilary suggested that I should prapare the figures and give the updated version to her tomorrow.
So... Photos scanned, and I will do this tonight.
Moreover, gel extraction kits had arrived. I purified the DNA for Sog_N1_New.

请找出以下推论的问题

我觉得就业根本不难
完全是现在的毕业生挑剔造成的


"我觉得为奴根本不辛苦
完全是以前的奴隶们太挑剔造成的"

News, important

My wife succesfully received the offer from University of Manchester, which means that she will study with me in the future in UK.
Her project is community breast cancer research among the Chinese/Chinese origin in UK.
There will be a big change of my life here, I guess.

有趣的网页，有关拉格朗日插值法的

http://www.cut-the-knot.org/Curriculum/Calculus/LagrangeInterpolation.shtml

Todo 12-04-07

Forgot to write the report yesterday...
The draft of the report is mostly done. I will collect some information from the lab tody, and submit it to my supervisor.

一个笑话

引用如下：

他们贴那种图我就想到神经所的那个笑话，他们花两年教出了一只会数到5的猴子，据说举世无双，请了外国脑外科大夫开了脑袋做预实验，效果大好，簇拥去喝酒了，留下个研究生看猴子，研究生把呼吸机关了，全麻的猴子窒息死了

结合这个视频看，想必会对人生有所启迪。
http://www.tudou.com/programs/view/iz4pdXMAVVA/

Todo 11-04-07

Paper...

Report 10-04-07

The report is half finished.
Work on.

CDs and book

Moonspell - Memorial
Tristania - Widow's Weed
Why is sex fun? The evolution of human sexuality

Arrived today.

Todo 10-04-07

The same as yesterday.

Report 09-04-07

Nothing.... just writing...

"六月新娘"之从来

月前闻吾妻谓六月之新娘必当幸福美满，夫妻恩爱。
今日览万维网始知其源：
此说起于西方之地，盖因欧罗巴之古国罗马，以女神朱诺（Juno）为六月之名（June）。此朱诺女神者，实为古希腊海拉（Hela）女神之罗马异名也，乃司婚产之神。故世人皆以六月婚娶，当受女神之赐，而此说得成。

Darft part 1 2nd report

Abstract

During the development of Drosophila Melanogaster embryo, the product of Decapentaplegic (Dpp) gene plays an essential role in the final organization of dorsal-ventral pattern. It is a homolog of Bone Morphogenetic Proteins 2 and 4 (BMP 2/4) and acts as an extracellular morphogen to form a gradient with the effect of some other regulators including short gastrulation (Sog), twisted gastrulation (Tsg), Dcg1, Viking (Vkg) and Tolloid (Tld). Among these Dpp regulators, Sog and Tsg are products of zygotic genes, and Vkg and Dcg1 belong to the type IV collagens. In our project, we checked the interaction between Tsg, Vkg, Sog and Dpp by GST pull down assay to confirm the result from other researches, and tried to divide the Sog and Dpp proteins into smaller fragments in order to find out the region where the interaction occurs. We also performed in situ hybridization on Dpp and Dcg1 mutated embryos and wild type embryos to compare the expression patterns of Race and U-shaped (Ush) genes which are related to the expression of Dpp. And we found that there are differences between the wild type and mutated embryos.

Introduction

As kind of insect, Drosophila Melanogaster undergoes germ layer differentiation named gastrulation and forms endoderm, mesoderm and ectoderm during embryo development. This differentiation process rises from the different spatial positions of the cells in the embryo and is mostly controlled by morphogens. (Ashe and Briscoe, 2006)
During the early stages of embryo Drosophila Melanogaster development, the product of spätzle gene acts as a morphogen to establish the dorsal-ventral pattern (Morisato and Anderson, 1994). Then, the control is taken away by other morphogens. In previous studies, it has been reported that two homologs of Bone Morphogenetic Proteins 2 and 4 (BMP 2/4), Decapentaplegic (Dpp) and Screw (Scw) which are members of TGF-β superfamily, are the control factors for the formation of dorsoal ectoderm in Drosophila Melanogaster. Further researches indicated that Dpp plays the main role since all dorsal cells assume ventral lateral fates and the mutant phenotype of the zygotically required genes appears the most severely with the lack of Dpp (Arora and Nusslein-volhard, 1992; Ferguson and Anderson, 1992a). Experiments also showed that after the dorsal-ventral (DV) axes is patterned, the effect of the morphogenetic Dpp depends on the local concentration level. In detail, high Dpp level leads to the fate of being amnioserosa whilst lower levels make the cell become dorsal ectoderm tissue (Shimmi and O'Connor, 2003). The Dpp/Scw functions by binding to a receptor complex which is supposed to be composed of type I and type II transmembrane serine/threonine kinases (Hogan, 1996; Nakayama et al., 2000). It has been elucidated that in Drosophila, the type I receptor Thick veins (Tkv) interact with the Dpp molecule and the type II receptor Punt (Put) to form a heteromeric complex. The active Put within this complex phosphorylate the Tkv consequently and thus activates the associated type I kinases which will phosphorylate the cytoplasmic protein Mothers against Dpp (Mad). The Mad which belongs to the Smad superfamily then function inside of the cell and lead to the differentiation and in this way the signal of Dpp is transduced. Moreover, in the signal transduction of Scw, it seems that another type I receptor Saxophone (Sax) takes the place of Tkv in Dpp signal transduction. However experiment also showed that high level of Tkv is able to compensate the loss of Sax, and indicates that these two morphogens shares a similar intracellular pathway. (Affolter et al., 2001)
Based on the knowledge above, the regulation of dorsal ectoderm and amnioserosa formation by BMP signalling pathway is suggested to be achieved by the gradient distribution of Dpp. This hypothesis is confirmed by the visualization of Dpp distribution in wild type and mutant Drosophila embryos (Ferguson and Wang, 2005; Shimmi et al., 2005). The work done by the Shimmi group also revealed the fact that the Dpp and Scw may function effectively by forming a Dpp-Scw heterodimer which is able to induce a 10 to 100 fold phosphorylated Mad accumulation than Dpp or Scw homodimer in the cells exposed to these materials (Shimmi et al., 2005).
An interesting and indispensable phenomenon of the gradient of Dpp is that it is not smoothly distributed. It has been shown that Dpp distribution has a peak level at the 8-10 dorsalmost cells which will later form the amnioserosa, and there is a sharp fall of Dpp level at the edge of the dorsalmost cells where cells on the different sides of the confine receive high and very low BMP signal (Shimmi and O'Connor, 2003). This step gradient ensures the normal development of amnioserosa and dorsal epidermis.
According to the model of morphogen distribution which concerns the Dpp/Scw heterodimer alone, this phenomenon is unable to be explained. In the classical model, specified cell produces the morphogen and the morphogen diffuses to the tissue around either via extracellular or intracellular pathway. Thus a morphogen concentration gradient which peaks at the secreting cell and smoothly deduced along with the increasing distance to the secreting cell (Ashe and Briscoe, 2006). In this way, the formation of this step gradient of Dpp should be created by another mechanism with some other factors.
So far we have already known that Dpp signalling activity is regulated by the products of two zygotic genes short gastrulation (Sog) and twisted gastrulation (Tsg), two type IV collagens Viking (Vkg) and Dcg1, and at last a protease Tolloid (Tld) (Ashe, 2005). It is known that Sog gene is a homologue of Xenopus Chordin (Chd) gene which produces antagonist of BMPs both structural and functional. (FERGUSON and ANDERSON, 1992b; Piccolo et al., 1996). And later studies have discovered that Tsg is also a secreted protein which acts as extracellular antagonists of BMP (Chang et al., 2001; Ross et al., 2001). These works gave the evidence that Sog and Tsg bind to BMP directly and inhibit the interaction between BMP and its receptor (Tkv and Put) to form a Tsg-Sog-Dpp-Scw complex in order to block the signal transduction (Ashe, 2005). However, this inhibition will not destroy the BMP itself, and the formed complex can be divided into the original single molecular as well.



References

Affolter, M., T. Marty, M.A. Vigano, and A.J. ska. 2001. Nuclear interpretation of Dpp signaling in Drosophila. EMBO J. 20:3298-3305.
Arora, K., and C. Nusslein-volhard. 1992. Altered mitotic domains reveal fate map chages in Drosophila embryos mutant for zygotic dorsoventral patterning genes. Development. 114:1003-1024.
Ashe, H.L. 2005. BMP Signalling: Synergy and Feedback Create a Step Gradient. Current Biology. 15:375-377.
Ashe, H.L., and J. Briscoe. 2006. The interpretation of morphogen gradients. Development. 133:385-394.
Chang, C., D.A. Holtzman, S. Chau, T. Chickering, E.A. Woolf, L.M. Holmgren, J. Bodorova, D.P. Gearing, W.E. Holmes, and A.H. Brivanlou. 2001. Twisted gastrulation can function as a BMP antagonist. Nature. 410:483-487.
Ferguson, C., and Y.C. Wang. 2005. Spatial bistability of Dpp-receptor interactions during Drosophila dorsal-ventral patterning. Nature. 283:583-583.
Ferguson, E.L., and K.V. Anderson. 1992a. decapentaplegic Acts As a Morphogen to Organize Dorsal-Ventral Pattern in the Drosophila Embryo. Cell. 71:451-461.
FERGUSON, E.L., and K.V. ANDERSON. 1992b. Localized enhancement and repression of the activity of the TGF-β family member, decapentaplegic, is necessary for dorsal-ventral pattern formation in the Drosophila embryo. 113:583-597.
Hogan, B.L. 1996. Bone morphogenetic proteins in development. Current Opinion in Genetics & Development. 6:432-438.
Morisato, D., and K.V. Anderson. 1994. The spätzle gene encodes a component of the extracellular signaling pathway establishing the dorsal-ventral pattern of the Drosophila embryo. Cell. 76:677-688.
Nakayama, T., Y. Cui, and J.L. Christian. 2000. Regulation of BMP/Dpp signaling during embryonic development. Cell Mol Life Sci. . 57:943-956.
Piccolo, S., Y. Sasai, B. Lu, and E.M.D. Robertis. 1996. Dorsoventral Patterning in Xenopus: Inhibition of Ventral Signals by Direct Binding of Chordin to BMP-4. Cell. 86:589–598.
Ross, J.J., O. Shimmi, P. Vilmos, A. Petryk, H. Kim, K. Gaudenz, S. Hermanson, S.C. Ekker, M.B. O'Connor, and J.L. Marsh. 2001. Twisted gastrulation is a conserved extracellular BMP antagonist. Nature. 410:479-483.
Shimmi, O., and M.B. O'Connor. 2003. Physical properties of Tld, Sog, Tsg and Dpp protein interactions are predicted to help create a sharp boundary in Bmp signals during dorsoventral patterning of the Drosophila embryo. Development. 130:4673-4682.
Shimmi, O., D. Umulis, H. Othmer, and M.B. O'Connor. 2005. Facilitated transport of a Dpp/Scw heterodimer by Sog/Tsg leads to robust patterning of the Drosophila blastoderm embryo. Cell. 120:873-886.

Todo 09-04-07

Paper work...

在线听音乐的站

www.musicovery.com
www.last.fm

仁者乐山，智者乐水

权力，经济，军队
平衡
宗教 折中与妥协

Todo 08-04-07

I should perform another GST pull down, however I am realy bothered.
So today I will just stay in my room and do paper reading and writing - even this is more boring...