Genetics Chapter 7

vossome's version from 2015-10-19 06:17

Section 1

Question Answer
Transposable ElementsDNA segments that can move location
TE's in Prokaryotes can move to...Another position on the same chromosome, a plasmid, or a phage genome
TE insertion in coding seq affects...Gene Function
TE insertion into promoter region affects...Gene expression pattern
TE Frequency...Is low due to high rates of cell death

Section 2

Question Answer
Insertion Sequences ISSimplest TE in prokaryotes
TransposaseGene for mobilization and insertion of DNA
Inverted Repeats IRIdentical sequences at the terminals in opposite directions
NOTE: Look at Steps of transposition of ISDo it you bitch, now
Prokaryote IS range is...768bp to 5kp
Transposition occurs at...Frequency characteristic for each IS Element

Section 3

Question Answer
Transposons TNSimilar to IS but carry additional genes and are more complex
Two Types of TNsComposite and Noncomposite
Composite TNsCarry genes flanked by IS elements and produce target site duplication
Non-Composite TNsCarry genes but do not have IS elements but centrally coded transposition enzymes
ISL and ISRIS left and IS right found in composite TNs, supply Transposase and IRs
TransposaseCatalyzes insertion of TNs
ResolvasePromotes recombination event with transposition
Conservative TranspositionTn is lost from original position when moving
Replicative Transposition Tn is duplicated so original and new position both have copies
NOTE: Look at Cointegration ModelDo it damnit

Section 4

Question Answer
TEs in EukaryotesTwo types, depend on usage of RNA intermediate
Two types of TEs in EukClass I and Class II
Class I(Retrotransposon) Uses and RNA intermediate. LOOK AT NOTES FOR PROCESS
Class IIDoes not use RNA and moves directly from donor to target
Which TE can excise from donor site?Class II (reverses mutations)

Section 5

Question Answer
Ty Element in YeastClass I, encodes two proteins and contains two repeats
GAGProtein coded by Ty and packages RNA intermediate into virus like particle
POLProtein coded by Ty and responsible for reverse txn and intergration
Long Terminal Repeats LTRContains a promoter and sequences recognized by pol

Section 6

Question Answer
Ac (in Corn)Activator, 4563 bps, Autonomous, Short IRs, Transposase
Dc (in Corn)Dissociation, Made by Ac deletions, No Transposase, Short IRs, Non-autonomous
Dc needs Ac for...Mobilization (does not have transposase)
McClintockStudied purple Indian Corn kernels, First demonstration of TEs

Section 7

Question Answer
Human RetrotransposonsClass I, Two types
Two Types of H TEsLINEs, SINEs
LINEsLong Interspersed Nuclear Elements, Autonomous
SINEsShort Interspersed Nuclear Elements, Non-autonomous, Need LINEs
Difference between Ty and LINEs/SINEsNo LTRs
Insertional MutagenesisWhen LINEs/SINEs inserted into genes cause diseases