Positional Cloning Animation

  • December 2019
  • PDF

This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA


Overview

Download & View Positional Cloning Animation as PDF for free.

More details

  • Words: 487
  • Pages: 23
Genomics What its genomics?

Genomics Structural Genomics

Functional Genomics Positional cloning

Functional Genomics Techniques How can we measure the pattern of gene expression in a given tissues over time?

„

Northern blots

In situ hybridization

Microarrays and Microchips „

Allow you look at expression of all the potential mRNAs in a cell at the same time

DNA microarrays

•DNAs spotted on slide •025-1 nl •Spots 100 µm diameter •200-150 µm apart

Spots DNAs directly on chip! „

„

Synthesize oligonucleotides on surface of a chip Photolithography

Growing oligonucleptides on a glass surface

Oligonucleotide whole genome arrays „

„

Can use genome sequences to generate oligonucleotide arrays to identify each gene product in a genome. How long must an oligonucleotide be to uniquely identify one human gene?

„

„

„

Sequence of n bases will occur every 4n bases What is the minimum number of bases that will occur about once in the human genome 4n bases such that n results in 4n at least the size of human genome

„

4n = 3.5 X 109

„

n = 16

Affymetrix Inc.

Check out this animation

http://www.bio.davidson.edu/Courses/genomics/chip/chip.html

Statistics 6116 Yeast Genes 96 Intergenic regions + lots of control samples Dr. Patrick O. Brown Stanford

Positional Cloning „

A strategy for cloning genes based solely on map position

Cloning Disease Genes „

Requires knowledge of the protein

„

Sickle cell anemia

„

Huntingtons Chorea

„

Cystic Fibrosis

Map based cloning Involves isolating a marker piece of DNA whose location is known and which is tightlylinked to the gene you are trying to clone

Map based cloning „ „ „ „ „ „ „ „

North America United States Cascade Range Mount Ranier Puget Sound Downtown Seattle Seattle Center Space Needle

Cystic Fibrosis „

„

First human disease gene cloned solely on the basis of position determined by linkage analysis Took 4 years Lap-Chee Tsui, Francis Collins and John Riordan isolated the gene in 1989

Strategy „

„

„

„

Screened a large number of families for RFLP linked to CF Found RFLP called DOCR-917 that was tightly linked to CF Somatic cell hybrids showed that DOCR-917 is on Ch. 7 1985: reported linkage between 7q22 and 7q31.1 (Met andD788) „

– 1.7 Mb apart

How do you know when you have arrived? „ „

Human genes have CpG islands at 5’ ends Important genes are often highly conserved „

„ „

„

(zoo blots)

Gene should be transcribed Gene sequence should be different in normal and diseased individuals CF gene (CFTR) finally isolated from cultured sweat gland cells

Cystic Fibrosis Gene „

„ „ „ „ „

Used probe to isolate cDNA (6000 bp) from diseased and normal individuals Diseased gene had deletion of 3 bp Normal ATC ATC TTT GGT (Ile Ile Phe Gly) Disease D508 ATC AT T GGT (Ile Ile Gly) 68% of all CF caused by D508 Remaining 32% caused by > 190 different mutations

Related Documents

Cloning
May 2020 24
Cloning
August 2019 41
Cloning
May 2020 28
Cloning
May 2020 27
Cloning
April 2020 16