What parasites do pt. 3 Flashcards
When are lifecycle changes the most clear
Most noticeable in organisms that have obtain different habitats at different life stages
When do most developmental changes occur
Just before transmission or upon arrival in a new host
How does a a parasite know to develop
The environment is either just about to change or has suddenly changed radically
-parasites actively monitor their environment and regulate their development
What is getting changed within the parastie through all this life cycle changes
Gene expression
How come gene expression changes
During its time in certain cycles it does need to do certain things. It does not need certain genes to be active and take energy so during this time it represses those genes, turns them off
Is phenology important to a parasite
Yes because parasites do not follow developmental timetable
Why do parasites not follow a developmental timetable
Due to transmission and all other event that have to happen within its lifecycle to continue are totally unpredictable
What are developmental signals a parasite follows
Signals originating from both host and parasite
Environmental cues
Example of parasite cues
Trypanosoma brucei changes from long slender to short stumpy due to a high density of slender releasing a signal called stumpy induction factor (SIF). When it reaches a certain threshold the slender turn into stumpy
A state of developmental arrest, to prevent premature development in the larval stages
Hypobiosis
Why does hypobiosis occur
It allows the alteration of the timetable so nonparasitic form does not outpace their ability to enter a host
What happens once a parasite enters a new host
Rapid development occurs
Why does a parasite hold onto premade mRNA
It allows for quick translation to make proteins to be able to quickly adapt to its new home since this place is vastly different from its last
Epigenetics
Changes in phenotype or gene expression caused by mechanism other than alterations in DNA sequence
What has histone acetylation shown to do in epigenetics
Plays a key role in conversion of Plasmodium and Toxoplasma
-It affects if the transcription of the DNA will even get read
