The Opsins and Nuclear Receptors of the Honey Bee

The studies presented here illustrate the value of the recently sequenced honey bee genuine for the expansion of our knowledge of insect evolution and physiology. In the first study, a novel lineage of insect opsins is described based on the identification of a novel opsin gene, pteropsin, in the honey bee. This novel lineage of insect opsins is more closely related to the vertebrate visual opsins than to invertebrate opsins. The detailed mapping of the tissue distribution of the complete set of honey bee opsins suggested a non-visual role for pteropsin and provided molecular confirmation for the previously characterized spectral sensitivities of honey-bees to UV, blue, and long wavelengths. Chapter 2 represents the first genome-based overview of the nuclear receptors of Apis mellifera. I found a striking conservation in the number of nuclear receptor genes between the honey bee and Drosophila, suggesting the prevalence of an essential set of nuclear receptors and their functional conservation across the Insecta. A novelty uncovered by my annotation is the presence in the honey bee genome of a third insect nuclear receptor gene homologous to human PNR, which I have named AmPNRlike. Nuclear receptors function as key regulators of neuronal structure. In the third chapter, I have explored the role of nuclear receptors as candidate regulators of neuronal plasticity in the insect mushroom bodies. The brains of older bees exhibit an expansion of the neuropil of the mushroom bodies relative to younger workers. Nuclear receptors transduce 20-hydroxyecdysone and juvenile hormone signals to regulate insect development through a coordinated transcriptional cascade. My experiments revealed that the transcriptional cascade characteristic of metamorphosis is active in adult honey bee mushroom bodies and can be induced by 20-hydroxycedysone. I have therefore established the presence of endocrine signaling through nuclear receptors in the adult mushroom bodies. Chapter 3 concludes with a model that places nuclear receptor activation in the mushroom bodies in the context of adult brain plasticity.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Entomology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Velarde Montecinos, Rodrigo Ariel

Contributors dc:contributor

• Fahrbach, Susan E.
• Robinson, Gene E.

• Biology, Entomology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3300925

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86462