RNA is remarkably versatile It can sense the
“RNA is remarkably versatile. It can sense the levels of various compounds inside a cell and switch genes on and off to adjust these concentrations, for example. ”
+ effector - effector L L AT Readthrough AAT T Termination L L ASD SD Translation ON low temperature ASD SD Translation OFF RNA itself can play as a chemical or temperature sensor to determine whether the coded information should be executed SD Translation OFF high temperature ASD SD Translation ON 李承維
Does Mill’s experimental condition correctly reflects the early history of earth atmosphere?
In 2008, however, lightning began to look promising once again. Cleaves and his colleagues suspected that the failed experiments were flawed because the sparks might have produced nitrogen compounds that destroyed any newly formed amino acids. When they added buffering chemicals that could take up these nitrogen compounds, the experiments generated hundreds of times more amino acids than scientists had previously found. What is the experimental detail?
A reassessment of prebiotic organic synthesis in neutral planetary atmosphores Cleaves HJ, Chalmers JH, Lazcano A, Miller SL, Bada JL. Orig Life Evol Biosph. 2008 Apr; 38(2): 105 -15
Stanley Miller and origin of life (1953) Harold Clayton Urey (1893 – 1981) whose pioneering work on isotopes earned him the Nobel Prize in Chemistry in 1934
S. L. Miller, Science 117, 528 (1953). S. L. Miller, “A production of organic compounds under possible primitive earth condition”. Ph. D Thesis, University of Chicago (1954). The Miller–Urey experiment or Urey–Miller experiment?
Miller die on 20 May 2007 Miller’s original notebooks and a few boxes were kept at Mandeville Special Collections, Geisel Library University of California, San Diego
3 May 2008 eruption of the Chaiten volcano, Chile Science 322: 404; 2008
“Probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed, ” Darwin: On the Origin of Species (1859)
Jasper Nance Valter Jacinto Dohduhdah jennyhsu 47 Do we really share one same ancestor? Romain Guy
Jasper Nance Valter Jacinto Dohduhdah jennyhsu 47 DNA synthesis (replication) DNA RNA synthesis (transcription) RNA Protein synthesis (translation) protein Amino acids Yes, we do share one same ancestor! 高慧芸 Romain Guy
生命形式由簡而繁的演化 (evolution) • 遺傳資訊的變異(variation in population) • 變異的生物特徵可以遺傳 (inheritance) • 天擇 (natural selection)
Michael Strock mutant normal … GGC TGT GGC TAG … CCG ACA CCG ATC DNA transcription … GGC UGU GGC UAG transcription RNA translation … Gly - Cys - Gly Stop … GGC TAT GGC TAG … CCG ATA CCG ATC … GGC UAU GGC UAG translation Protein … Gly - Tyr - Gly Stop
血紅素基因單一密碼的改變造成血紅素蛋白單一 胺基酸的改變進而影響了紅血球的構形 (鐮刀狀貧血) DNA CAC GTG GAC TGA GGA CTC Sequence GTG CAC CTG Amino acid Valine Histidine Leucine sequence ACT CCT GAG Threo nine Proline Glutamic acid Nomal DNA CAC GTG GAC TGA GGA CAC CTC Sequence GTG CAC CTG Amino acid sequence Valine Histidine Leucine ACT CCT GTG GAG Threo nine Proline Valine Glutamic acid Mutant E. M. Unit, Royal Free Hospital School of Medicine/Wellcome Trust Photo Library
Natural selection on human gene mutation Sickle-cell anemia: hemoglobin B gene (HBB) Aa heterozygoes partially protected against malaria But aa homozygotes suffer adverse health effects Heterozygote advantage -- but only where malaria is present See: anthro. palomar. edu/synthetic/synth_4. htm
氧:厭氧生物的第一號殺手! 找地方躲起來! 消滅清除它! 自由基: superoxide dismutase — aerobes and aerotolerant anaerobes 過氧化物:catalase (nearly all organisms), peroxidase (in some) 聰明地利用它!
(A) Combustion H 2 ½ O 2 (B) Biological Oxidation H 2 Separate into H+ and electrons 2 H+ 2 e- Explosive Release of Heat Energy 李承維 H 2 O ½ O 2 + 2 H+ + 2 e李承維 H 2 O
無所不在的原核生物:細菌 Volker Brinkmann Spherical cells e. g. Streptococcus Rod-shaped cells e. g. Escherichia coli Spiral cells e. g. Treponema pallidum
F L F F: food vacuole L L: lysosome 李承維 柔軟的外套: 吞噬作用(phagocytosis)
Symbiosis Within a Modern Cell Chlorella, the green, photosynthetic, single-celled algae living symbiotically within the cytoplasm of the Paramecium. Antonio Guillén
1. Duplication of the original system, and 2. Establishment of control over multiple copies. Duplication 李承維 Differentiation
團藻 (Volvox)
Unicellular ancestor of animals joanna 8555 Divergence of animal and plant lineage Acquisition of multicellularity eucaryotic common ancestor cell Unicellular ancestor of plants Acquisition of chloroplasts 高慧芸 Jim Hammer 在這裡還有那一類的多細胞生物沒有被提到?
See you next time!
作品 作者/來源 授權條件 臺灣大學動物所 李承維 NASA http: //commons. wikimedia. org/wiki/File: SLMILLER. JPG 2010/09/07 visited NASA http: //commons. wikimedia. org/wiki/File: Harold_Urey. jpg 2010/09/17 visited Adam P. Johnson et al, The Miller Volcanic Spark Discharge Experiment, Science 322: 404; 2008 “Probably all the organic beings which………. ” Darwin the Origin of Species Jasper Nance http: //commons. wikimedia. org/wiki/File: Spirogyra_cell. jpg 2010/09/17 visited
作品 作者/來源 授權條件 Max Westby http: //www. flickr. com/photos/max_westby/54275159/ 2010/09/17 visited Dohduhdah http: //commons. wikimedia. org/wiki/File: Mushroom. IMG_6515. JPG 2010/09/17 visited jennyhsu 47 http: //www. flickr. com/photos/jennyhsu 47/3500534128/ 2010/09/17 visited Romain Guy http: //www. flickr. com/photos/romainguy/230420772/ 2010/09/17 visited 臺灣大學動物所 高慧芸 Michael Strock http: //commons. wikimedia. org/wiki/File: DNA_Overview. p ng 2010/09/17 visited
作品 授權條件 作者/來源 E. M. Unit, Royal Free Hospital School of Medicine/Wellcome Trust Photo Library http: //0 rz. tw/14 scf 2010/10/27 visited National Human Genome Research Institute http: //commons. wikimedia. org/wiki/File: Sicklecells 4. jpg 2010/09/17 visited http: //www. ncbi. nlm. nih. gov/bookshelf/br. fcgi? book=dbio &part=A 1971 2010/10/27 visited 臺灣大學動物所 高慧芸 Rick Jan Kluitenberg http: //commons. wikimedia. org/wiki/File: SIKKEL. JPG 2010/09/17 visited Mariana Ruiz Villarreal http: //commons. wikimedia. org/wiki/File: Average_prokaryo te_cell-_en. svg 2010/09/07 visited
作品 作者/來源 授權條件 臺灣大學動物所 李承維 Mariana Ruiz Villarreal http: //commons. wikimedia. org/wiki/File: Average_prokaryo te_cell-_en. svg 2010/09/07 visited 臺灣大學動物所 李承維 CDC/Janice Carr http: //commons. wikimedia. org/wiki/File: Streptococcus_pne umoniae. jpg 2010/09/28 visited Volker Brinkmann http: //commons. wikimedia. org/wiki/File: Salmonella_typhi murium. png 2010/09/28 visited
作品 作者/來源 授權條件 CDC/ Dr. David Cox http: //commons. wikimedia. org/wiki/File: Treponema. Pallidu m. jpg 2010/09/28 visited Mariana Ruiz http: //commons. wikimedia. org/wiki/File: Animal_cell_struc ture_en. svg 2010/09/17 visited 長庚大學 周成功 臺灣大學動物所 李承維 長庚大學 周成功
作品 作者/來源 授權條件 Antonio Guillén http: //www. flickr. com/photos/microagua/3309071169/ 2010/09/17 visited 臺灣大學動物所 李承維 http: //commons. wikimedia. org/wiki/File: Alga_volvox. png 2010/09/17 visited 長庚大學 周成功 http: //www. youtube. com/watch? v=bk. Vh. LJLG 7 ug 2010/10/27 visited 臺灣大學動物所 高慧芸
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