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Last class. Separating and visualizing DNA. Experimental design. Working with DNA. Genes/regions of interest in larger pieces of DNA. Isolate gene/region of interest to study it/products. Examples of things you can do with DNA: - - -. First step:. Need DNA “scissors”!. Cloning.
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Last class Separating and visualizing DNA Experimental design
Working with DNA Genes/regions of interest in larger pieces of DNA Isolate gene/region of interest to study it/products Examples of things you can do with DNA: - - - First step: Need DNA “scissors”!
Cloning What is a “vector?” What is “cloning” a gene?
Cloning a DNA piece into a plasmid Plasmid Open plasmid Isolate gene Mix Ligate plasmid
How? Use __________________ to cut gene Use __________________to open plasmid Use __________________to ligate
Restriction Enzymes (REs) Enzyme that cuts DNA Called a “Restriction” enzyme because:
Type II REs Type II REs “cut” inside dsDNA Type II REs cut at specific recognition sites RE site = specific DNA sequence Almost always a palindromic sequence because: No length limits for RE site. Usually 4-8 nucleotides
Type II REs RE1 GCATGCCGTACG RE1 GCCGTA ATGCCG
Reading primary literature Reviews, news, etc. ALWAYS biased! - News: Stem cells will allow us to live forever - Religious right: Billions of dollars wasted on useless, immoral research - Research: Stem cells MIGHT be therapeutic You might want to look at the actual research! Importance of forming your OWN opinions - Elections, democracy and political spin! - Informed decisions!
Reading primary literature Primary means of scientific communication - Build upon existing research - Do not duplicate existing research Sharing of ideas for scientific progress
Organization of a scientific paper Abstract/Summary Introduction Results Discussion Methods & Materials References
The parts of a paper: Establish rationale Abstract/Summary - Brief version of paper - Main question/s addressed - Experimental approach - Main result/s & their significance Introduction - Background and context for the research - Purpose/Hypothesis
The parts of a paper: Present data Results - Data generated by experiments (Graphs, charts, tables, etc.) - Explanations to understand results Methods & Materials - Science should be reproducible! - Allows reader to duplicate results
The parts of a paper: Put in context, future Discussion - Brief summary of results - Significance - Future directions References - Credit for past work - Resource for additional information/reading
How to read primary literature Not easy! - Usually quite jargony - Practice, practice, practice Sequential - Each experiment will build on previous one Active & Critical - Research, not text book! - Conclusions may not be correct!
Textbook VS Primary literature Textbook Literature Assumption Ideas are correct Ideas are wrong! How /Method Unimportant Critical! Prior knowledge Low requirement High requirement! Reading Passive Active!
Building a knowledge base “By utilizing FRET to monitor protein-DNA interactions, we examined assembly of the human holoenzyme.” eLife 2013;2:e00278 Glucose–TOR signalling reprograms the transcriptome and activates meristems Nature 496, 181–186 Read, read, read, read, read.
How to read a paper Main question/s or hypothesis/es of paper Individual figures - Purpose of the experiment - How does data relate to main question/s? Active & Critical - Does the data support conclusions? - Additional experiments? - Future directions - Controversy? Paradoxes?
Example Main hypothesis: Yeast SUB1 (PC4) is required for NHEJ yku REQUIRED for NHEJ BamHI = 5’ overhang
C. elegans life cycle C. elegans Life Stages from George L. Sutphin and Matt Kaeberlein at Univ. of Washington, Seattle.
Molecular mechanisms lin-14, lin-28, lin-29 were all proteins lin-4 = NOT protein! lin-4in intron of another gene!
Molecular mechanisms lin-4 is an RNA! lin-4is a small (~22nt) RNA! How does small RNA regulate level of another protein?
Paper 1 lin-4 & let-7 Only in C. elegans? Found let-7-like sequences in other organisms Small RNAs Universal regulators? Small RNAs How widespread? Roles?
RNAi + + + +
Paper 1 RNA interference mechanism = miRNA mechanism Small RNAs generally regulate genes?
Paper 1 Found let-7-like sequences in other organisms Small RNAs Universal regulators? Small RNAs How widespread? Roles? How might you identify small RNAs?
Your assignment… Download assignment Answer each question about indicated figure Do not go over space limit/Do not change font! Save/Convert to PDF Upload to Turnitin Deadline: 18-Oct-2013 4:00pm
Paper reading ~ Lab report reading! Peer review is nota waste of time! Read lab reports critically ~ Reading paper! Gain: process, not just getting feedback Peer review = Universal career requirement!
Lab report 1 and Peer review Lab report one deadline varies Due before your lab section Peer review deadline is 01/28, 11:59pm Reviews released on 01/29, 12:00am Cannot do reviews after deadline!!!