Genome Number Size Organism (Mb) Genes 1.新基因的起源与进化 Bacteria Haemophilus influenzae 1,700 基因是怎样产生的? Mycoplasma genitalun 0.58 470 Archaea Archaeoglobus fulgidus 2.2 2,500 研究基因起源的意义: Methanosarcina barkeri 4.8 3,600 Eukaryotes 深入探讨物种的形成和 Saccharomyces cerevisiae 300 (yeast, a fungus) 分子进化、物种进化之 Caenorhabditis elegans 100 20,100 间的关系 (nematode) Arabidopsis thaliana 120 27000 根据基因产生的规律设 (mustard family plant Drosophila melanogaster 165 13,700 计新的生物活性药物 (fruit fly) Oryza sativa(rice) 430 42,000 Zea mays(corn) 2,300 32.000 Mus musculus(house mouse) 2,600 22,000 Ailuropoda melanoleuca 2,400 21,000 (giant panda) Homo sapiens(human) 3,000 <21.000
➢ 基因是怎样产生的？ ➢ 研究基因起源的意义： Mycoplasma genitalun 0.58 470 – 深入探讨物种的形成和 分子进化、物种进化之 间的关系 – 根据基因产生的规律设 计新的生物活性药物 II.新基因的起源与进化
研究一个新基因的起源的两个步骤: √首先,需要了解一个新的基因结构在自然 界的某一生物个体中产生的突变步骤。 √其次,需要知道单一个体的新基因如何扩 散到一个物种的所有个体并固定下来
✓ 首先，需要了解一个新的基因结构在自然 界的某一生物个体中产生的突变步骤。 ✓ 其次，需要知道单一个体的新基因如何扩 散到一个物种的所有个体并固定下来。 ➢ 研究一个新基因的起源的两个步骤 ：
新基因起源研究现状 >1993年,华裔学者龙漫远发现 了第一个年轻的基因--“精卫” TAG TAG 基因( JIngwen约2.My)。 TAG Duplicate copy 2: yande ATG TAG ande Recombination of exons TAA AATAAA “拯救了危机中的达尔文理论” on Adh-derived regon Degenerate yande region The origin of jingwei严
The origin of jingwei ➢ 1993年，华裔学者龙漫远发现 了第一个年轻的基因---“精卫” 基因（jingwei,约2.5 My ）。 新基因起源研究现状 ➢“拯救了危机中的达尔文理论
精卫填海 In an ancient legend from China (San Hai Jing), Jingwei, a daughter of the Emperor Yande(first Chinese emperor 3000 B.C), tragically drowned while swimming in the East China Sea. Jingwei was then reincarnated as a beautiful bird that drops stones and wood into the sea in an attempt to fill it, thus preventing others from drowning. We used the name jingwei"because this gene avoided the usual fate of processed gene(death)and was" reincarnated into a new structure with novel function
精 卫 填 海 In an ancient legend from China (San Hai Jing), Jingwei, a daughter of the Emperor Yande (first Chinese emperor 3000 B.C.), tragically drowned while swimming in the East China Sea. Jingwei was then reincarnated as a beautiful bird that drops stones and wood into the sea in an attempt to fill it, thus preventing others from drowning. We used the name 'jingwei" because this gene avoided the usual fate of processed gene (death) and was "reincarnated" into a new structure with novel function
Table 1 Molecular mechanisms for creating new gene structures Mechanism Process Examples Comments Exon shuffling fucosyltransferase, ing 19% of exons in ectopic recombination of exons and domains have been formed from distinct genes by exon shuffing Gene CGB, Cid, RNASE1B Many duplicates classic model of have probably duplication with evolved new functions di Retroposition PGAM3, Pgk2, PMCHL1 1% of human DNA is new gene duplicates PMCHL2, Sphinx retroposed to new are created in new Transcripton locations 因产生的分 genomic positions Reverse tranccnpton by reverse transcription or other processes Mobile element HLA-DR-1. human DAF Generates 4% of new a mobile element lungerkine mRNA exons in human also known as a mNSC 1 mRNA protein-coding genes transposable element (E, sequence is directly recruited by er TE sequences host genes Lateral gene transfer. acetylneuraminate lysase Most often reported 分子机制 a gene is laterally Organism B Eschenchia coli in prokaryotes and (horzontally) transmitted mutU and muts recently reporte among organisms in plants Gene fusion/fission. Fatty-acid synthesis enzymes Involved in the two adjacent genes formation of.5% fuse into a single gene Fission of prokaryotic genes or a single gene splits into two genes De novo origination Rare for whole a coding region gene origination originates from a might not be rare previously non-coding for partial gene genomIc region origination The origin of new genes: glimpses from the young and old. Nat Rev Genet, 2003, 4: 865
新 基 因 产 生 的 分 子 机 制 The origin of new genes: glimpses from the young and old. Nat Rev Genet,2003, 4: 865