Biology Reference
In-Depth Information
Table 4.1
Mating combinations and specialist genotypes
Queen
gametes
Drone gametes
P1
h
P2
h
P1
h
P2
l
P1
l
P2
h
P1
l
P2
l
P1
h
P2
h
P1
h
P1
h
P2
h
P2
h
P1
h
P1
h
P2
l
P2
h
P1
l
P1
h
P2
h
P2
h
P1
l
P1
h
P2
l
P2
h
P1
h
P2
l
P1
h
P1
h
P2
h
P2
l
P1
h
P1
h
P2
l
P2
l
P1
l
P1
h
P2
h
P2
l
P1
l
P1
h
P2
l
P2
l
P1
l
P2
h
P1
h
P1
l
P2
h
P2
h
P1
h
P1
l
P2
l
P2
h
P1
l
P1
l
P2
h
P2
h
P1
l
P1
l
P2
l
P2
h
P1
l
P2
l
P1
h
P1
l
P2
h
P2
l
P1
h
P1
l
P2
l
P2
l
P1
l
P1
l
P2
h
P2
l
P1
l
P1
l
P2
l
P2
l
Note:
h e queen is a heterozygote for both loci and can produce four possible
gametes with respect to these two loci. Male genotypes are haploid. Combinations for
of spring from mating the heterozygous queen with all possible male genotypes are
shown. Shaded boxes show the extreme specialist genotypes. h ere is no single mating
that will produce progeny with both specialist genotypes.
genotype, and genetic variation will be maintained in the population.
Multiple mating is also favored because it increases the variance in
the genotypes and results in more of the specialist classes in a colony
(Table 4.1).
4.4.1.2 Genetic Evidence for the Model
Ge ne tic mapping of pollen- and
nectar-foraging behavior has revealed major quantitative trait loci as-
sociated with the amount of pollen stored in the comb and pollen- and
nectar-foraging behavior (Chapter 6). A quantitative trait locus (QTL)
is a gene responsible for a quantitative trait. A quantitative trait is one
that requires a measurement to show the phenotypic variation. For ex-
ample, eye color in humans is a qualitative trait. It is classii ed as brown,
blue, or green. However, height is quantitative; one must measure it to
show the distribution of variation. We mapped QTLs for the amount of
pollen stored in the comb (pollen hoarding) and found two major QTLs
initially and a third in a subsequent map. h ese QTLs represented re-
gions on a chromosome where more than one gene af ecting the pollen-
hoarding trait could reside. We subsequently constructed genomic
maps for the individual traits of pollen and nectar foraging. h ey
mapped to the same QTLs, demonstrating pleiotropy (when a gene has
ef ects on more than one trait). Altogether we mapped three major
