> Ok. I suppose then, if someone were to cross, say, N. RAFFlesiana
> (lowland) with N. VILLosa (highland), the N.vill * N.raff might
> (?should?) enjoy highland conditions more than N.raff * N.vill?
> I would think these sort of traits influence metabolism more
> than the way the hybrid looks. Am I on the mark here?
Interesting idea. This could be true, although many metabolic
enzymes are encoded by nuclear DNA and therefore would come from both
parents. It would presumably depend on which of these were the most
sensitive to temperature.
> > In the second example, DNA can be packaged or chemically
> > modified differently in the maternal or paternal gametes. This
> > is called imprinting, and at least in mice, can lead to expression
> > of only the genes inherited from one parent. In the third example, the
> > egg is loaded with proteins and RNAs needed for early development in
> > the mother. These maternally provided components can, in principle,
> > lead to differences in the organism.
>
> Hmm, these two sort of sound like the same thing, almost... Chemical
> modifiers would be proteins... It's just the timing of the effect
> that's different, right?
They are not really the same. In imprinting, the DNA that comes
from one parent is modified in the developing gametes in that parent, but
the effect is on expression of genes in the offspring. In the case of
maternal affect, the proteins and RNAs are produced in the mother and
required for early development. These can affect how the offspring
develop, but do not selectively influence the expression of maternal or
paternal genes.
Wayne Forrester