Biology Reference
In-Depth Information
Greg Hunt had successfully taken RAPD markers, cut the DNA prod-
ucts from gels, sequenced them, and made specii c primers of high reli-
ability. h ese primers amplii ed markers called sequence tag site mark-
ers. h is greatly improved the quality of the genetic markers we were
using to tag our QTLs. In addition, he produced a marker for the honey
bee gene
Amfor,
which encodes an enzyme that was shown by Yehuda
Ben Shahar, a student of Gene Robinson, to be involved in the onset of
foraging. We thought that we might as well take a look at that region of
the genome because we could easily make a marker. Hybrid virgin
queens derived from a high- and low-strain cross were backcrossed to
either a single high-strain or low-strain drone to produce high- and
low-strain backcross workers. We collected them when they became
foragers and uncovered a complex network of QTLs af ecting the phe-
notypes we measured, including a QTL at or near
Amfor.
We desig-
nated the region around
Amfor pln4.
We had a fourth QTL. h is does
not mean that
Amfor
is responsible for the behavioral dif erences we
observed; that is much more dii cult to coni rm. But it does mean that
Amfor
or something close to it is responsible for some signii cant amount
of the behavioral variation observed.
We also constructed two new QTL maps from the low- and high-
backcross workers. A new kind of DNA marker was used, amplii ed
fragment length polymorphism (AFLP). h is allowed a map to be con-
structed in less than six months. Several new QTLs were located in
both maps for each of the traits. Some had individual ef ects, others
only in interaction with other QTLs. Some QTLs were statistically sig-
nii cant; others were “suggestive,” that is, statistically signii cant if one
was looking only at that one marker, but not meeting the more rigorous
requirements for signii cance when one was looking at many dif erent
(about 400) markers at the same time. Rueppell subsequently con-
structed QTL maps of the age of foraging onset (age of i rst foraging,
AFF) and the responses of bees to sugar, with the same result. Collec-
tively, several new QTLs were identii ed and coni rmed. h e take-home
message from all these studies is that the QTLs we mapped represent
complex interactive networks of genes with broad ef ects on the behav-
ioral traits of our pollen-hoarding syndrome.
