PLSC 311 Lecture Notes - Lecture 9: Parthenogenesis, Ovariole, Hymenoptera
Lecture 9: Genetics of the honey bee
Hoe does the system of hyplodiploidy work in honey bees?
- During egg (gamete) formation in the queen’s body each diploid (2n=32) cell of the egg-
forming tissue in her ovaries undergoes meiosis (happing in the egg tubules= ovarioles)
this yields 4 egg cells, each being haploid (n=16)
- During sperm (gamete) formation in the drone each haploid (n=16) cell of the sperm-
forming tissue in the testes will find normal chromosome doubling, but without cell
division at meiosis I (no reduction in chromosome number)
oThus essentially drones produce sperm cells (n=16) by mitosis
oAs a result, when egg and sperm cells unite to form a zygote the chromosome
number of 2n=32 is restored (get a female diploid bee)
-Mutation: change in a gene, that results in an altered trait (know that it can be induced
high temperature, radiation, high UV light)
oHoney bee can find the occurrence of white eyed mutation in honey bees
oNormally the queen worker and drone have black eyes (compound eyes)
Example of inheritance:
Inheritance of the white eyed drone (male)
Queen Ww (black eyed) heterozygous Drone W (black eyed)
2 possible types of gametes produced Sperm cells are all W
W w W W
These will be black-
eyed drones
White eyed drones A female with black
eyes (homozygous
dominant)
A female with black
eyes (heterozygous)
- Queen has to be heterozygous to produce a white eyed drone
oBy parthenogenesis (unfertilized eyes) will become male, so will only get one
gamete either W or w
oHalf will be W and other half will be w
Inheritance of the white eyed females (Q,W)
Queen Ww (black eyed) heterozygous Drone w (white eyed)
2 possible types of gametes produced Sperm cells are all w
W w w w
These will be black-
eyed drones
White eyed drones A female with black
eyes (heterozygous)
A female with white
eyes (homozygous
recessive)
- Drone sperm is use for fertilized eggs to produce females, one gamete from the queen
and one from the drone
- This cross does not happen in nature due to the drone eyes not working in daylight
(don’t have normal pigment in eyes), so cannot catch the queen to mate, so only
happens with AI (To get a white eyed female)
find more resources at oneclass.com
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Document Summary
During egg (gamete) formation in the queen"s body each diploid (2n=32) cell of the egg- forming tissue in her ovaries undergoes meiosis (happing in the egg tubules= ovarioles) this yields 4 egg cells, each being haploid (n=16) Drone sperm is use for fertilized eggs to produce females, one gamete from the queen and one from the drone. This locus is estimated to have ~20 different alleles. Example: xa,xb,x . : j. woyke (poland) found that if he protected these diploid drone individuals from cannibalism, these diploid drones were found to be inferior: smaller testes, produce smaller quantities of sperm as adults. If an individual is heterozygous at the sex allele (example: xa,xe), then this individual is a diploid female (become queen or worker) If the individual is homozygous with a genotype such as xa, xa, then a diploid drone will arise (will be eaten) If hemizygous at this allele (example: xa), then it is simple a normal haploid drone.
