Mike wrote:
> http://www.plosbiology.org/plosonlin...l.pbio.0020043

Most helpful, Mike. Although this particular effect seems specific to
the scale insects ("Obligate chimerism—the presence of two genetically
distinct cell lineages in every individual at each life stage—is found
in a few families of scale insects, but nowhere else in nature.") it did
lead me to the correct Google search, which turned up this reference:

http://www.actahort.org/books/603/603_70.htm

It seems that this effect occurs because the Pinot cultivars possess 3
instead of 2 copies of one chromosome, which permits one layer of cells
to use one version and another layer to use a different version. Not
only that, but if the two layers of cells are separated and allowed to
develop into grapes, both layers give rise to grapes that are distinct
from Pinot Gris:

http://tinyurl.com/2j3ey

Truth is stranger than fiction yet again!

Mark Lipton