《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)》请在三一文库上搜索。
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: Chromosomes Mitosis Meiosis DNA, 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
2、 Chapter 2-6, p. 25-92 http:/ccms.nut.edu.tw/juang/JRH/Amino.htm www-rohan.sdsu.edu/sepa/genetics.htm http:/ehrweb.aaas.org/ehr/books/2_dominant.html http:/library.thinkquest.org/06aug/00440/superbibliography.html Tarjan I, et al. Early prosthetic treatment of patients with ectodermal dysplasia: A c
3、linical report. J Prosthet Dent 2005;93:419-24 www.genetic-programming.org What you need to know about cancer. Sci Am 1996;289:28-119 Gibbs WW. Untangling the roots of cancer. Sci Am 2003;289:56-65 Bowden JR, et al. DNA microarray technology: insights for oral and maxillofacial surgeons. Br J Oral M
4、axillofac Surg 2004;42:542-5 Kuo WP, et al. Microarrays and clinical dentistry. JADA;2003;134-456-62 Ralf D. The first discovery of DNA. Sci Am 2003;96:320-8 www.estrellamountain.edu/faculty/farabee/biobk/BioBookglossL.html juang.bst.ntu.edu.tw/BCbasics/Amino1.htm http:/ for genetics (1) and (2):,
5、參考資料,Genetics,Chromosomes,Refs. 1, 4,All living cells 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 ma
6、inly of DNA, which consists of four different building blocks 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 interve
7、ning nucleotide sequences. In the chromosomes of eukaryotes, the uncondensed 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
8、from 50 million to 263 million bases. With few exceptions (e.g., red blood cells), 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
9、) to Los Angeles (洛杉磯 - 美國加州),Refs. 1, 4,http:/ 1, 17,During mitosis (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 hi
10、stones or nuclei. In its relaxed state, the DNA can be accessed for transcription, 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
11、 be the carriers of genes,Genetics,Chromosomes,Different stages of DNA condensation 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,Chromosome
12、s,Refs. 1, 17, 18,1. Chromatid. One of the two identical parts of the chromosome 2. Centromere. 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 kary
13、otype The karyotype of the human female contains 23 pairs of homologous chromosomes: 22 pairs of autosomes (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,Chromos
14、omes,Refs. 1, 16,Genetics,Chromosomes,The chromosomes in other living organisms differ,Refs. 1, 4,Genetics,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 unde
15、r various conditions. When a gene is expressed, it makes a transcript (抄本),Genetics,Chromosomes,Refs. 1, 17,Chromosomal 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
16、Partial chromosomal dysplasia (malformation), which are usually the result of a defective crossover,Genetics,Chromosomes,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 t
17、hat sounds like a cat. They have wide-set eyes, a small head and jaw and are mentally retarded. Wolf-Hirschhorn syndrome, which is 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,Chromos
18、omal aberrations (2) Missing or additional chromosomes, called aneuploidy, which are the result of an incomplete chromosomal segregation, many of which are associated with cancer (Duesberg hypothesis). Example: Down syndrome (extra chromosome 21). This is also known as mongolism or trisomy 21. Sympt
19、oms are decreased muscle tone, asymmetrical skull, slanting eyes and mental retardation,Genetics,Chromosomes,Refs. 2, 17,Chromosomal aberrations (2) Klinefelters Syndrome (XXY). Men with Klinefelter syndrome are usually sterile. They tend to have longer arms and legs and tend to be taller than their
20、 peers. Other common symptoms are lack of emotion, fatigue, apathy and an increased tendency to develop psychiatric disorders Turner syndrome (X instead of XX or XY). In Turner syndrome, female sexual characteristics are present but underdeveloped. People with Turner syndrome often have a short stat
21、ure, 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 body, with the exception of ova and spermatozo, and called somatic cells. Cellular division is achieved by mitosis during a part of t
22、he somatic cells life span, called mitotic cycle,Function of mitosis is to create an exact copy of each chromosome and, through division of the original cell, distribute an identical set of chromosomes to each daughter cell,Genetics,Normal cell division - Mitosis,Ref. 1,Ref. 9,Normal Cell Cycle,Ref.
23、 18,Genetics,Normal cell division Stages of Mitosis,Ref. 1,Mitosis is composed of 4 stages: metaphase, prophase, anaphase and telophase In each of these 4 stages, the chromosomes are distributed in a specific arrangement,www.lewport.wnyric.org/jwanamaker/animations.htm,www.educypedia.be/education/bi
24、ologyanimations.htm,In metaphase, chromosomes stain intensely & are arranged almost symmetrically at both sides of equatorial plane of the cell The appearance of a metaphase chromosome resembles the letter “X”,Genetics,Normal cell division Stages of Mitosis,Ref. 1,http:/ cell division takes place, e
25、ach chromosome splits vertically 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,Stages of Mitosis,Genetics,Normal cell division First Meiosis,Line Up,Cross-over (metaphase),Segment
26、 exchange,Ref. 1, 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 Deoxyribonucleic acid (DNA),Chromosomes contain DNA DNA contains the basic code or template that carries all gen
27、etic 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. 11,Genetics,Molecular composition of chromosomes Deoxyribonucleic acid (DNA),Hydrogen Bond,Ref. 1,Ref.
28、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 : Found in the circular chromosome of the mitochondria Maternally inherited Passed from the mother t
29、o 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 RNA (hnRNA) RNA can be found in both the nucleus and cytoplasm of a cell,Genetics,Mol
30、ecular composition of chromosomes Ribonucleic acid (RNA),Ref. 1,mRNA: blueprint of genetic DNA for the coding of proteins tRNA: carries message for DNA to ribosomes in cytoplasm, in which proteins are produced rRNA: transfers amino acids from cytoplasm to mRNA, positioning amino acids in proper sequ
31、ence to form polypeptides and hence proteins hnRNA: 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 transcribed (copied) to messenger RNA in a process similar to DNA replication
32、. 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 read the genetic code from the mRNA, and transfer RNAs (tRNA
33、s) 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 discoverers of DNA - double helix,Genetics,Evolution of chromosome?,Ref. 8,Genetics,Summaries,Knowing: Composition of chromosomes 2. Purpose and procedures of mitosis 3. Purpose and procedures of meiosis 4. DNA, RNA, transcription, translation,
链接地址:https://www.31doc.com/p-3359027.html