Lecture 8 Flashcards
Who wrote the paper?
Weaver
What does the paper investigate?
Maternal effects and other forms of environmental programming that are sustained over the lifespan of the animal
What maternal effect was the focus?
How attentive the mother was to the offspring
What effect was shown by the attentiveness of the mother?
More attentive mother = less fearful offspring
Less attentive mother = more fearful offspring
How was stress/fear measured?
HPA axis
Stress causes CRF release, which causes release of glutocoritcoid. glutocorticoid then affect metabolism and the immune system. But exist in negative feedback loop, suppressing CRF release.
What effect will an attentive mother have on HPA axis in later life?
Serotonin release due to attentive mother increases NGFI-A, the transcription factor for the glutocorticoid receptor (GR), increasing GR levels which persists into later life
Which promoter has increased use in attentive mother offspring?
Promoter of exon 7
What was shown by sodium bisulphite analysis?
Difference in methylation of CG dinucleotides in promoter of exon 7, in particular at the 5’ end of the NGFI-A binding site. With higher methylation shown in offspring of low attentive mothers
How was behaviour of the mother shown to be driving this methylation difference?
Swapping offspring from high attentive to low attentive mother caused increase in methylation almost up to level of offspring with low attentive from birth
How does maternal effect correlate with histone acetylation and the interaction between NGFI-A and the promoter?
Attentive behaviour increases histone acetylation and the amount of interaction between NGFI-A and the promoter in exon 7
How does the NGFI-A act to increase acetylation levels?
Its recruits CBP, a histone acetyltransferase
What effect does this acetylation have?
Open chromatin - allows more NGFI-A to bind and maybe allow demethylation (??)
How can GR expression be increased in offspring of non-attentive mothers?
Trichostatin
