Colin Brent
Research Interests and Current Projects
The primary focus of my research is to elucidate the mechanisms regulating behavioral and physiological development in eusocial insects, such as ants, honey bees and termites. The colonial organisms have well-developed castes exhibiting characteristic differences in behavior, morphology and reproductive capability. The process of caste differentiation is the result of a highly canalized developmental response to stimuli from nestmates and other environmental sources. My work focuses on the identification of these influential stimuli and delineating the underlying neuroendocrine processes that transduce such information into the behavioral and physiological responses characteristic of individual castes. By elucidating these systems, we can better understand the physiological constraints and the environmental pressures under which social complexity may have evolved.
Endocrinology of Temporal Polyethism: Adult honey bee workers exhibit temporal polyethism, displaying different suites of behaviors depending on their age and social environment. The pattern of these behavioral shifts is under both genetic and hormonal control, and is influenced by earlier developmental events and by colony conditions. Using strains selectively bred to exhibit divergent adult behavioral phenotypes, we are exploring the long-term effects of differential endocrine activity during pupal development, while concurrently trying to isolate the neuronal and genetic bases of their differences.
Biogenic Amine Modulation of Endocrine Activity: There is some evidence that variation in the expression of biogenic amines (serotonin, dopamine, octopamine) and their receptors may play a role in modulating hormone production. Using a variety of assays, we are trying to determine how various amines can influence the biosynthetic and secretory activity of the major endocrine organs regulating caste development.
Role and Regulation of Cuticular Hydrocarbon Expression: Many social insects express semiochemicals encoding caste- and sex-specific information, and these may act as regulators of conspecific development. Using termites as a model organism, we are examining how cuticular hydrocarbon production and expression is hormonally controlled, and whether these serve as pheromones to control nestmate differentiation. This work will establish how colony reproductive dynamics are maintained, thereby enhancing our understanding of the evolution of termite eusociality.
Selected Publications
CS Brent, C Schal, EL Vargo (2007) Effects of Social Stimuli on the endocrine systems of maturing queens of the dampwood termite Zootermopsis angusticollis. Physiological Entomology 32: 26-33.
CS Brent, C Peeters, V Dietmann, R Crewe, EL Vargo (2006) Hormonal correlates of reproductive status in the queenless Ponerine ant, Streblognathus peetersi. Journal of Comparative Physiology A 192: 315-320.
CS Brent, C Schal, EL Vargo (2005) Endocrine changes in maturing primary queens of Zootermopsis angusticollis. Journal of Insect Physiology 51: 1200-1209.
CS Brent, EL Vargo (2003) Changes in Juvenile Hormone in Maturing Virgin Queens of Solenopsis invicta. Journal of Insect Physiology 49: 967-974.
CS Brent, JFA Traniello (2002) The effects of supplemental dietary nitrogen on reproduction in the dampwood termite Zootermopsis angusticollis. Environmental Entomology 31: 313-318.
CS Brent, JFA Traniello (2001) Influence of sex-specific stimuli on ovarian maturation in both primary and secondary reproductives of the dampwood termite Zootermopsis angusticollis. Physiological Entomology 26: 239-247.