bio 207 lecture 8.docx

2 Pages
82 Views
Unlock Document

Department
Biology (Biological Sciences)
Course
BIOL107
Professor
Lesley Harrington
Semester
Fall

Description
BIOL207 B01 Lec08 2014-01-22 CHAPTER 4 (cont’d) A. Mutation Classification (cont’d); a. point mutation (substitute one base for another) b. insertion or deletion (indel); c. effect on gene function (Muller moprhs) i. amorph = null = no wt protein function; complete loss of functions; if there is a stop codon at the start of the gene and it is not made, that would be a null ii. hypomorph = partial loss of wt function; partial loss of function; perhaps the catalytic site has changed so it is not as strong as it was before; not a complete loss of function, but some functions iii. hypermorph= more of the wt function than in wt; more of the mutant function is present than the wildtype; you make a darker purple flower than the typical purple flower; can be a mutation in the catalytic site making the purple proteins faster; this gene has more of the function than the wildtype; VERY RARE iv. neomorph = a new function that is different from wt; not more, not less, it’s just a whole new function; changing the purple flower to a pink flower, a new function, a function that’s different from the widltype v. antimorph = a new function that works in opposition to wt d. loss-of-function (amorph, hypomorph) vs. gain-of-function (hypermorph, neomorph, antimorph); antimorph looks like an amorph, but it works against the wildtype; antimorph is a loss of a wildtype function but antimorph can gain a new function; wildtype protein is still made but there is a mutation that givesANOTHER GENE a different function as well; look phenotypically null, but it’s working in opposition, maybe it degrades the substrate; VERY RARE!; haven’t lost the wildtype function but gained a new function working against the wildtype function; e. amorph, hypomorph tend to be recessive because wt alleles tend to be haplosufficient; wildtype alleles tend to be haplosufficient’most amorphs and hypomorphs are recessive f. hypermorph, neomorph, antimorph tend to be dominant; dominant/ new functions/ opposition functions tend to be dominant; g. Loss of function tends to be recessive, gain of function tends to be dominant; B. Mutant screening: Salvation of Doug http://bio.research.ucsc.edu/people/sullivan/savedoug.html a. learn about almost any biological process by identifying mutants that disrupt that process; randomly pick and mutate genes then observe the effects b. mutagenize (chemical, physical, biological) thousands of individuals; mutagenize gametes/ adults (e.g. fruit flies), we wonder what we can find via a mutant screen; we can expose them to radiation/ feed them radioactive food; we have a wildtype fly and each + one of the flies’wildtype cells is AA. Then we mutate it toAA , but this does not mean that every single cell will be mutated; mutagenisis occurs on a cell by cell basis; we get thousands of base pairs changed when we walk outside or are exposed to radiation in an airplane; most of the mutations that occur are a loss of function (recessive) and the wildtype function (dominant) will usually make up for these mutations c. Where do we have to start to look for changes in p
More Less

Related notes for BIOL107

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit