Biology Reference
In-Depth Information
producing diploid female progeny. The behavior appears to be caused by alter-
native splicing of a gene homologous to the
gemini
transcription factor of
Drosophila
. It appears that this switch can allow rapid worker ovary activation in
Cape honey bees, turning the altruistic worker genome into a parasite.
Krieger and Ross (2002)
identified a single major gene (
Gp-9
, encoding a
pheromone-binding protein) that may affect fire ant (
Solenopsis invicta
) workers'
ability to recognize queens and regulate their numbers. Some fire ant colonies
have multiple egg-laying queens (polygyne form), whereas others have single
queens (monogyne social form). Apparently, colony-queen number is associated
with an allele of the
Gp-9
gene.
Lucas and Sokolowski (2009)
studied the ant
Pheidole pallidula
and showed
that the differences in major and minor workers are due to the ant
foraging
gene, which encodes a cGMP-dependent protein kinase. Majors, which are
larger and defend the nest, have higher protein levels in five cells in the anterior
face of the ant brain, whereas minors do not. Minors are involved in foraging
and manipulating the level of the protein increases defense and reduces forag-
ing behavior.
The descriptions mentioned above are a small sample of the wealth of infor-
mation being obtained on the genetics of behavior in social insects. The com-
plete genome sequences of bees and ants will allow even more detailed analysis
of behaviors in the future.
11.11 Conclusions
Great advances have been made in understanding the behavior of insects
using the many new molecular tools, especially those based on whole-genome
sequencing. The ability to sequence the genomes of multiple inbred lines of
D. melanogaster
, for example, has provided exceptional opportunities to dissect
the genetic bases of behavior. Statistical methods have advanced, and methods
to evaluate groups of insects by recording their behavior and analyzing the data
with computer programs provide new opportunities, as well, to obtain high-
throughput data (
Buchen 2009, Walsh 2009
).
However, the report by
Vanin et al. (2012)
indicating that circadian behavior
of
D. melanogaster
is different under natural conditions (populations contained
in cages outdoors) than in the laboratory indicates great care must be taken to
develop appropriate experimental methods in order to obtain a realistic under-
standing of an insect's behavior. Another example of the importance of experi-
mental methods is the design of “choice tests.”
Martel and Boivin (2011)
discuss
