Biology Reference
In-Depth Information
female, one must inherit two dif erent forms (alleles) of the
csd
gene; one
must be heterozygous. Individuals that have two copies of the same allele
are homozygous; haploid individuals have just one copy, are hemizygous,
and are ef ectively homozygous. Homozygous and hemizygous individu-
als develop into males (Figure 4.1). Diploid
B. hebetor
males are sterile.
With the development of instrumental insemination technology in
the late 1940s and early 1950s came the ability to control the mating of
honey bee queens. Early honey bee geneticists wanted to use the inbred-
hybrid method of breeding that was so successful in the production of
hybrid corn. Maternal lines of honey bees were inbred for a few genera-
Queen
Drone 1
Drone 2
X
1
X
2
X
1
X
3
X
1
X
1
X
2
X
1
X
1
X
3
X
2
X
3
Diploid
Males
Figure 4.1.
Diagram of sex determination in the honey bee. Solid lines represent
egg gametes; dashed lines represent sperm. h e queen mated with two males,
one having a sex allele identical to one of hers, the other dif erent. Only the
chromosome containing the
csd
locus is represented. Half the of spring derived
from drone 1 are homozygous and develop into diploid males. Normal females
have two dif erent alleles, and normal males have just one set of chromosomes.
From Laidlaw, H. H. and R. E. Page. 1997.
Queen Rearing and Bee Breeding,
Fig. 93. Wicwas Press.
