《病理学含口腔病理学.ppt》由会员分享，可在线阅读，更多相关《病理学含口腔病理学.ppt（45页珍藏版）》请在三一办公上搜索。
1、病理學(含口腔病理學),陳玉昆副教授:高雄醫學大學 口腔病理科 07-31211012755 yukkwakmu.edu.tw,Genetics(2),基因學(2),Understanding:ChromosomesMitosisMeiosisDNA,RNA,protein(transcription,translation),學 習 目 標,Oral Pathology for the Dental Hygienist.Olga AC Ibsen,Joan Anderson Phelan,4th edition,2004,p.216-45 陳嘉芬 現代遺傳學 Chapter 2-6,p.25
2、-92http:/ccms.nut.edu.tw/juang/JRH/Amino.htmwww-rohan.sdsu.edu/sepa/genetics.htmhttp:/ehrweb.aaas.org/ehr/books/2_dominant.htmlhttp:/library.thinkquest.org/06aug/00440/superbibliography.htmlTarjan I,et al.Early prosthetic treatment of patients with ectodermal dysplasia:A clinical report.J Prosthet D
3、ent 2005;93:419-24www.genetic-programming.org What you need to know about cancer.Sci Am 1996;289:28-119Gibbs WW.Untangling the roots of cancer.Sci Am 2003;289:56-65Bowden JR,et al.DNA microarray technology:insights for oral and maxillofacial surgeons.Br J Oral Maxillofac Surg 2004;42:542-5Kuo WP,et
4、al.Microarrays and clinical dentistry.JADA;2003;134-456-62Ralf D.The first discovery of DNA.Sci Am 2003;96:320-8www.estrellamountain.edu/faculty/farabee/biobk/BioBookglossL.htmljuang.bst.ntu.edu.tw/BCbasics/A http:/,References for genetics(1)and(2):,參考資料,Genetics,Chromosomes,Refs.1,4,All living cell
5、s contain information which tells them how to develop.This information is contained in chromosomes,inside the cell nucleus,encoded in genes.,Genetics,Chromosomes,What is a chromosome?Chromosomes:Tightly coiled microscopic structures made up mainly of DNA,which consists of four different building blo
6、cks called bases(A,T,C,G).The four bases are repeated millions of times to form each chromosome,Refs.1,4,A chromosome is,minimally,a very long,continuous piece of DNA,which contains many genes,regulatory elements and other intervening nucleotide sequences.In the chromosomes of eukaryotes,the unconde
7、nsed DNA exists in a quasi-ordered structure inside the nucleus,where it wraps around histones(structural proteins),and where this composite material is called chromatin,Genetics,Chromosomes,Human chromosomes range in length from 50 million to 263 million bases.With few exceptions(e.g.,red blood cel
8、ls),each of the trillions of cells in the human body contains a complete set of chromosomes-the genome.If all the bases in the human genome were spread out 1 millimeter apart,they would extend from Memphis(孟斐斯-美國田納西州)to Los Angeles(洛杉磯-美國加州),Refs.1,4,http:/,Genetics,Chromosomes,Refs.1,17,During mito
9、sis(nuclear division),the chromosomes are condensed and called metaphasic chromosomes.This is the only natural context in which DNA is visible with an optical microscope,Genetics,Chromosomes,Refs.1,17,Prokaryotes do not possess histones or nuclei.In its relaxed state,the DNA can be accessed for tran
10、scription,regulation,and replication Chromosomes were first observed by Karl Wilhelm von Ngeli in 1842 and their behavior later described in detail by Walther Flemming in 1882.In 1910,Thomas Hunt Morgan proved chromosomes to be the carriers of genes,Genetics,Chromosomes,Different stages of DNA conde
11、nsation Single DNA strand Chromatin strand(DNA with histones)(3)Condensed chromatin during interphase with centromere(4)Condensed chromatin during prophase(5)Chromosome during metaphase,Refs.1,17,Genetics,Chromosomes,Refs.1,17,18,1.Chromatid.One of the two identical parts of the chromosome 2.Centrom
12、ere.The point where the two chromatids touch,and where the microtubules attach 3.Short arm 4.Long arm,Genetics,Chromosomes,Refs.1,4,The complete set of chromosomes in the cells of an organism is its karyotypeThe karyotype of the human female contains 23 pairs of homologous chromosomes:22 pairs of au
13、tosomes(any chromosome that is not a sex chromosome)1 pair of X chromosomes The karyotype of the human male contains:the same 22 pairs of autosomes one X chromosome one Y chromosome,Genetics,Chromosomes,Refs.1,16,Genetics,Chromosomes,The chromosomes in other living organisms differ,Refs.1,4,Genetics
14、,Chromosomes,Refs.1,17,Chromosomes in different species,Genetics,Chromosomes,Refs.1,4,Gene-expression profiling is screening large numbers of genes to see whether or not they are active under various conditions.When a gene is expressed,it makes a transcript(抄本),Genetics,Chromosomes,Refs.1,17,Chromos
15、omal aberrations(1)The malfunction of either the chromosomal segregation or the crossover can lead to severe diseases.They can be divided into two classes:Chromosomal aberration or Partial chromosomal dysplasia(malformation),which are usually the result of a defective crossover,Genetics,Chromosomes,
16、Ref.17,Chromosomal aberrations(1)Examples are:Cri du chat syndrome,which is caused by the deletion of part of the short arm of chromosome 5.Victims make high-pitched cries that sounds like a cat.They have wide-set eyes,a small head and jaw and are mentally retarded.Wolf-Hirschhorn syndrome,which is
17、caused by partial deletion of the short arm of chromosome 4.It is characterized by severe growth retardation and mental defect.,Genetics,Chromosomes,Refs.2,17,Chromosomal aberrations(2)Missing or additional chromosomes,called aneuploidy,which are the result of an incomplete chromosomal segregation,m
18、any of which are associated with cancer(Duesberg hypothesis).Example:Down syndrome(extra chromosome 21).This is also known as mongolism or trisomy 21.Symptoms are decreased muscle tone,asymmetrical skull,slanting eyes and mental retardation,Genetics,Chromosomes,Refs.2,17,Chromosomal aberrations(2)Kl
19、inefelters Syndrome(XXY).Men with Klinefelter syndrome are usually sterile.They tend to have longer arms and legs and tend to be taller than their peers.Other common symptoms are lack of emotion,fatigue,apathy and an increased tendency to develop psychiatric disordersTurner syndrome(X instead of XX
20、or XY).In Turner syndrome,female sexual characteristics are present but underdeveloped.People with Turner syndrome often have a short stature,low hairline,abnormal eye features and bone development and a caved-in appearance to the chest,Genetics,Normal cell division-Mitosis,Ref.1,All cells in the bo
21、dy,with the exception of ova andspermatozo,and called somatic cells.Cellular divisionis achieved by mitosis during a part of the somatic cells life span,called mitotic cycle,Function of mitosis is to create an exact copy of eachchromosome and,through division of the original cell,distribute an ident
22、ical set of chromosomes toeach daughter cell,Genetics,Normal cell division-Mitosis,Ref.1,Ref.9,Normal Cell Cycle,Ref.18,Genetics,Normal cell division Stages of Mitosis,Ref.1,Mitosis is composed of 4 stages:metaphase,prophase,anaphase and telophaseIn each of these 4 stages,the chromosomes are distrib
23、uted in a specific arrangement,www.lewport.wnyric.org/jwanamaker/animations.htm,www.educypedia.be/education/biologyanimations.htm,In metaphase,chromosomes stain intensely&arearranged almost symmetrically at both sides of equatorial plane of the cellThe appearance of a metaphase chromosome resemblest
24、he letter“X”,Genetics,Normal cell division Stages of Mitosis,Ref.1,http:/,When cell division takes place,each chromosome splitsvertically at the centromere,and 46 chromatids(which now become chromosomes)form one daughter cell,while the other 46 chromatids form a second daughter cell,Ref.18,Genetics,
25、Stages of Mitosis,Genetics,Normal cell division First Meiosis,Line Up,Cross-over(metaphase),Segmentexchange,Ref.1,Genetics,Normal cell division Second Meiosis,Ref.1,Genetics,Ref.18,Mitosis vs Meiosis,Genetics,Mitosis vs Meiosis,Ref.18,Genetics,Ref.2,Genetics,Molecular composition of chromosomes Deox
26、yribonucleic acid(DNA),Chromosomes contain DNA DNA contains the basic code or template that carries all genetic information The basic unit of DNA is called a nucleotide A nucleotide is formed by a N-containing base,5-carbon sugar(deoxyribose),and a phosphate,Genetics,Deoxyribonucleic acid(DNA),Ref.1
27、1,Genetics,Molecular composition of chromosomes Deoxyribonucleic acid(DNA),Hydrogen Bond,Ref.1,Ref.11,Genetics,Double helical structure of DNA showing the bases,sugar,and phosphate connect with each other,Genetics,Molecular composition of chromosomes Deoxyribonucleic acid(DNA),Mitochondrial DNA:Foun
28、d in the circular chromosome of the mitochondria Maternally inherited Passed from the mother to all her offspring regardless of sex,Genetics,Molecular composition of chromosomes Ribonucleic acid(RNA),Ref.1,There are 4 types of RNA:Messenger RNA(mRNA)Transfer RNA(tRNA)Ribosomal RNA(rRNA)Heterogenous
29、RNA(hnRNA)RNA can be found in both the nucleus and cytoplasm of a cell,Genetics,Molecular composition of chromosomes Ribonucleic acid(RNA),Ref.1,mRNA:blueprint of genetic DNA for the coding of proteinstRNA:carries message for DNA to ribosomes in cytoplasm,in which proteins are producedrRNA:transfers
30、 amino acids from cytoplasm to mRNA,positioning amino acids in proper sequence to form polypeptides and hence proteinshnRNA:found within nucleus(precursor of mRNA),Genetics,Transcription of DNA to RNA to protein,When genes are expressed,the genetic information(base sequence)on DNA is first transcrib
31、ed(copied)to messenger RNA in a process similar to DNA replication.mRNA then leave the nucleus&enter the cytoplasm,where triplets of bases(codons)forming the genetic code specify the particular amino acids that make up an individual protein.This process,called translation,is accomplished by that rea
32、d the genetic code from the mRNA,and transfer RNAs(tRNAs)that transport amino acids to the ribosomes for attachment to the growing protein.,Ref.4,Genetics,Ref.1,Transcription of DNA to RNA to protein,Ref.12,Transcription of DNA to RNA to protein,Genetics,Ref.18,Transcription of DNA to RNA to protein,Genetics,Ref.13,1st discoverersof DNA-double helix,Genetics,Evolution ofchromosome?,Ref.8,Genetics,Summaries,Knowing:Composition of chromosomes2.Purpose and procedures of mitosis3.Purpose and procedures of meiosis4.DNA,RNA,transcription,translation,
