Lecture 38 Flashcards
What is positional cloning?
Isolating genes on the basis of their position on a genetic map; this is how the gene for CF was identified
What is Sanger sequencing?
dideoxyribonucloside triphosphate (ddNTP) lacks a 3’ -OH group, which terminates DNA synthesis; this sequencing is based on the termination of DNA synthesis after a dideoxy nucleotide gets incorporated and terminates extension of the DNA fragment; multiple fragments are produced with different end-points and the fragments are separated by gel-electrophoresis; the sequence obtained is the complement of the original template strand of the target DNA
What is Next Generation sequencing and what are its applications?
Includes illumina sequencing, which allows base cells to be made based on data from DNA sequences, pyrosequencing, which allows the sequencing of a single strand of DNA by synthesizing the complementary strand one base at a time, and third-generation sequencing, which allows sequence determination of single molecules of nucleic acids
How does NextGen sequencing help make metagenomics possible?
Metagenomics involves identification of organisms present in the intestine, sewage, a body of water, dirt, debris filtered from the air, etc; sequencing enables researchers to determine which types of microbes may be present in a microbiome
What is a humanized animal model?
Animal model, like a mouse, carrying functioning human genes, cells, tissues, and/or organs
What are the basic concepts of CRISPR/Cas system of gene editing?
Prokaryotic immune system that confers resistance to foreign genetic elements such as plasmids and phages; spacers recognize and cut these exogenous genetic elements; with the Cas9 protein and appropriate guide RNAs into a cell, the target organism’s genome can be cut at any desired location
What are transgenic animals?
Organisms permanently altered by the addition of a DNA sequence to its genome
What is the function of siRNAs?
Interferes with the expression of specific genes with complementary nucleotide sequences; functions by causing mRNA to be broken down after transcription thus eliminating the resulting protein product
What is site-directed mutagenesis and what is it used for?
Single nucleotide mutation is introduced into DNA; used to study gene function when appropriate restriction sites are not available
What are shRNAs?
Short hairpin RNA; artificial RNA molecule that pairs back on itself and forms a tight hairpin turn; used like siRNA for silencing target gene expression via RNA interference (RNAi)
