BACKGROUND: The honey bee is an important model system for increasing understanding of molecular and neural mechanisms underlying social behaviors relevant to the agricultural industry and basic science. The western honey bee, Apis mellifera, has served as a model species, and its genome sequence has been published. In contrast, the genome of the Asian honey bee, Apis cerana, has not yet been sequenced. A. cerana has been raised in Asian countries for thousands of years and has brought considerable economic benefits to the apicultural industry. A cerana has divergent biological traits compared to A. mellifera and it has played a key role in maintaining biodiversity in eastern and southern Asia. Here we report the first whole genome sequence of A. cerana. RESULTS: Using de novo assembly methods, we produced a 238 Mbp draft of the A. cerana genome and generated 10,651 genes. A.cerana-specific genes were analyzed to better understand the novel characteristics of this honey bee species. Seventy-two percent of the A. cerana-specific genes had more than one GO term, and 1,696 enzymes were categorized into 125 pathways. Genes involved in chemoreception and immunity were carefully identified and compared to those from other sequenced insect models. These included 10 gustatory receptors, 119 odorant receptors, 10 ionotropic receptors, and 160 immune-related genes. CONCLUSIONS: This first report of the whole genome sequence of A. cerana provides resources for comparative sociogenomics, especially in the field of social insect communication. These important tools will contribute to a better understanding of the complex behaviors and natural biology of the Asian honey bee and to anticipate its future evolutionary trajectory.

Three methods of communication were examined in the Middle Island tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae); defence behaviour, acoustic and chemosensory signalling. Previous studies had been limited to basic autecology and anecdotal evidence. This study was undertaken to understand the behaviours of this species to assist in conservation efforts. Defensive behaviours were elicited through repeated stimulation while aggressive behaviours were acquired through male-male battles. Femoro-abdominal stridulation was induced within both situations. Defensive stridulation functioned as alarm behaviour and was often accompanied by a visual display. Agonistic stridulation was executed by the eventual winner of combat. Aggressive battles were a progression of behavioural units of increasing risk on injury until an individual was determined the winner. Acoustic analysis was preformed on stridulations observed in aggressive and defensive behaviours. Stridulation was a broad band signal covering a range well above 16 kHz and possibly into the ultrasound range (>20 kHz). Two different forms of stridulation were identified; click train sound and hiss sound. High speed frame-by-frame analysis of stridulation and scanning electron micrographs of the abdomen and medial femur deciphered the mechanism and found the interaction of the cuticle to be unique among weta. Strikingly, micrographs also revealed two morphologies of abdominal projections; truncated ridges and columnar pegs. Both these points were not previously observed. Y-maze and partition tests were utilized for evidence of chemosensory signalling, while gas chromatography-mass spectrometry identified faecal volatiles in M. iisolata and 4 other weta species in a parallel study. Through partition experiments, evidence exists for a species-specific volatile pheromone and a sex-specific chemo-tactile pheromone. Dimethylsulphide, (CH3)2S, was present in the faeces of all 5 weta species, and may be produced by the individual.

Cilia are finger-like projections that extend from the surface of most cells. These microtubule-based structures serve important mechanical or sensory functions. Motile cilia have been implicated in fluid movement whereas the non-motile primary cilia have been shown to play a role in sensory signal transduction. There exists a dichotomy in the field that primary cilia have only sensory function and motile cilia only have mechanical function. The central question of this thesis project is "what are the structural and functional components of airway motile cilia and are these cilia sensory?" In Chapter 2, the role of Bardet-Biedl Syndrome (BBS) proteins in maintaining the structure and function of airway motile cilia is examined. We found that BBS proteins localize to the cilium and to ciliary-related structures in human airway epithelia. Using mutant mice we found that BBS proteins play an essential role in motile cilia structure and the loss of BBS proteins results in reduced ciliary beat. These proteins have previously been shown to play a role in primary cilia structure and function, and our studies indicate a novel function for BBS proteins. Chapter 3 examines the sensory role of motile cilia. Our data show that bitter taste receptors and components of the bitter taste signal transduction pathway localize to the motile cilia or to the ciliated cells. Ciliated cells also show an increase in intracellular calcium in response to bitter compounds, accompanied by a corresponding increase in cilia beat. The increase in intracellular calcium originates at the ciliated cells and is propagated to adjacent cells. Chapter 4 delves into the possibility that every motile ciliated cell also contains a single, primary cilium. Using immunostaining and Smoothened as a marker for primary cilia, we found that every group of motile cilia contains a single Smoothened-positive cilium. Furthermore, downstream components of the Sonic Hedgehog pathway are also present in ciliated cells. Chapter 6 is a summary chapter including possible explanations for observed outcomes and plans for future experiments. Our results indicate that the divide between primary and motile cilia may not be as great as has been previously thought.

cAMP is a second messenger in a variety of chemosensory receptors, including taste buds and glucose-sensitive pancreatic beta-cells. cAMP is modulated during taste transduction, yet the significance of cAMP changes and the taste cell types in which they occur (Type I glial-like; Type II Receptor; Type III Presynaptic) remain unclear. I developed techniques to image real-time changes in intracellular cAMP in taste cells using genetically-encoded cAMP reporters. This FRET-based reporter permits one to measure single-cell cAMP levels with excellent spatial and temporal resolution (Zaccolo & Pozzan 2002, Science 295:1711). Using a biolistic approach I have transfected rat fungiform taste buds with cAMP reporter plasmids. Focal application of bitter tastant to living fungiform tastebuds in situ produced a decrease in [cAMP]i within individual taste receptor cells. These results are qualitatively similar to previous biochemical measurements from homogenized taste tissue (Yan et al. 2001, Am J Physiol Cell Physiol 280:C742) but are now allowing us to examine the cAMP response in individual, identified cells. I next explored the effect of elevating cAMP on calcium levels, using Fura-2 imaging of isolated mouse vallate taste buds. Elevating [cAMP]i in taste buds evoked calcium responses in presynaptic/Type III taste cells, which do not express GAD1. cAMP induced responses were generated by calcium influx. Using pharmacological antagonists, I determined that the calcium influx triggered by cAMP is through L-type calcium channels, whereas influx following depolarization is primarily through P/Q-type calcium channels. Consistent with these data, single cell RT-PCR showed that the L-type subunit (alpha 1C) was expressed primarily in GAD-negative Presynaptic cells, while the P/Q-type (alpha 1A) was expressed in all Presynaptic cells. Thus, cAMP may modulate the function of synapses in some taste cells. Finally, we have developed a mouse strain expressing a cAMP reporter in a tissue-specific and tetracycline-inducible manner. We crossed this mouse with another strain expressing tet-activator in beta cells of the pancreas. Such islets responded to increasing concentrations of glucose (5.5 to 35mM) with an increase in cAMP levels. The half maximum of 9mM glucose for the cAMP response corresponds well with reported glucose concentrations that elicit insulin release from whole islets. Stimulating pancreatic islets with glucose is known to drive calcium influx into beta-cells. When we simultaneously imaged both second messengers, we found that cAMP changes precede and are independent of calcium changes. In conclusion, these studies have outlined novel potential functions for cAMP signaling in the transduction of both primary tastant and plasma glucose information. In addition, the flexibility of the tet-system will enable cAMP reporter expression in numerous cell types, including those which mediate gustatory transduction.

In Syrian hamsters, sexual preference requires integration of chemosensory and steroid cues. Although data suggest that separate pathways within the brain process these two signals, the functional significance of this separation is not well understood. Within the medial amygdala, the anterior region (MEa) receives input from the olfactory bulbs, whereas the posterodorsal region (MEpd) is sensitive to steroid hormones. Lesions of either the MEa or MEpd eliminated preference to investigate female over male odors. Importantly, males with MEpd lesions displayed decreased attraction toward female odors, suggesting a decrease in sexual motivation. In contrast, males with MEa lesions displayed high levels of investigation of both female and male odors, suggesting an inability to categorize the relevance of the odor stimuli. These results suggest that both the MEa and MEpd are critical for the expression of opposite-sex odor preference, although they appear to mediate distinct aspects of this behavior.

Antipredator defenses are ubiquitous in aquatic ecosystems. In the widely studied Chaoborus-Daphnia predator-prey system, Daphnia elicit a variety of phenotypically plastic responses to Chaoborus including: morphological, life history, and behavioral responses. While these inducible defenses benefit the prey, metal contaminants have been shown to interfere with chemosensory functions, thereby inhibiting antipredator defenses and decreasing survivorship. However, in lakes with a history of metal contamination, such as Kelly Lake in Sudbury, Ontario, there is evidence to suggest that Daphnia may have adapted to high, ambient copper concentrations. Using seven distinct Daphnia clones that were hatched from resting eggs from Kelly Lake, we examined morphological and life history traits when clones were exposed to either a nominal concentration of copper, kairomone, or a combination of both. As expected, clones displayed a variety of inducible responses in both kairomone-control and kairomone-copper treatments, which was attributed to genetic variability. Expected trade-offs in life history traits were not always observed, suggesting that inducible traits may be coupled. Furthermore, in contradiction to life history theory, one clone exhibited both increased somatic growth and increased reproductive output, indicating that clones likely adopted adaptive strategies to stressors rather than elicitng trade-offs in traditional traits. Our results indicate that environmentally relevant copper concentrations do not inhibit the induction of antipredator defenses in Daphnia from Kelly Lake, and we conclude that Kelly Lake Daphnia have developed an adaptive tolerance to copper. Adaptation to copper contamination may have implications for resilience in natural Kelly Lake populations. / Thesis (Master, Biology) -- Queen's University, 2012-04-03 19:33:59.137

Bakgrund: Många patienter i palliativ vård rapporterar en minskad, eller förändrad, förmåga att känna smak och lukt. Smak-och luktförändringar (SoL-förändringar) kan innebära lidanden för den enskilde patienten, men kan även påverka näringsintag samt få negativa följder i det dagliga livet. Syfte: Syftet var att rapportera om cancerpatienters erfarenheter av smak- och luktförändringar och påverkan och hantering av dessa i det dagliga livet när de är i palliativ fas. Metod: Kvantitativ data samlades in från åtta deltagare, under tre mättillfällen per deltagare, via ett frågeformulär. Kvalitativ data beståendes av kommentarer till frågorna, redovisades som citat. Resultat: Det var fem huvudfynd som framkom i resultatet. Ett övergripande tema som kunde urskiljas var sårbarheten och lidandet i samband med SoL-förändringar.  Vidare framkom att SoL-förändringar rapporterades av samtliga deltagare, dock inte vid alla mättillfällen. En definitionssvårighet av SoL-förändringar uppmärksammades också bland svaren. Ytterligare var aptitnedsättningar lågt rapporterade bland deltagarna. Detta stod i kontrast till illamående som rapporterades av samtliga deltagare. Diskussion: Sårbarheten och lidandet som uppkom i samband med Sol-förändringar kunde ge en negativ påverkan på det dagliga livet. Drivkraften att tillgodogöra sig föda för sin överlevnad återges med insikten att det ofta inte är för njutningens skull som måltider intas.  Resultatet visade på vikten av att SoL-förändringar uppmärksammas inom den palliativa sjukvården.

Animal chemosensation involves several families of G protein-coupled receptors (GPCRs) and, though some of these families are well characterized in vertebrates and nematode worms, receptors have not been identified for most metazoan lineages. In this dissertation, I use a combination of bioinformatics approaches to identify candidate chemosensory receptors in three invertebrates that occupy key positions in the metazoan phylogeny. In the sea urchin Strongylocentrotus purpuratus, I uncovered 192 candidate chemosensory receptors many of which are expressed in sensory structures including pedicellariae and tube feet. In the cephalochordate Branchiostoma floridae, my survey uncovered 50 full-length and 11 partial odorant receptors (OR). No ORs were identified in the urochordate Ciona intestinalis. By exposing conserved amino acid motifs and testing the ability of those motifs to discriminate between ORs and non-OR GPCRs, I identified three OR-specific amino acid motifs that are common in cephalochordate, fish and mammalian ORs and are found in less than 1% of non-ORs from the rhodopsin-like GPCR family. To further investigate the antiquity of vertebrate ORs, I used the OR-specific motifs as probes to search for orthologs among the protein predictions from 12 invertebrates. My search uncovered a novel group of genes in the cnidarian Nematostella vectensis. Phylogenetic analysis that included representatives from the major subgroups of rhodopsin-like GPCRs showed that the cnidarian genes, the cephalochordate and vertebrate ORs, and a subset of genes S. purpuratus from my initial survey, form a monophyletic clade. The taxonomic distribution of these genes indicates that the formation of this clade began at least 700 million years ago, prior to the divergence of cnidarians and bilaterians. Furthermore, my phylogenetic analyses show that three of the four major subgroups of rhodopsin-like GPCRs existed in the ancestor of cnidarians and bilaterians. The utility of the new genes I describe here is that they can be used to identify candidate olfactory cells and organs in cnidarians, echinoderms and cephalochordates that can be tested for function. These genes also provide the raw material for surveys of other metazoans as their genomes become available. My sequence level comparison between chordates, echinoderms and cnidarians exposed several conserved amino acid positions that may be useful for understanding receptor mediated signal transduction. ORs and other rhodopsin-like GPCRs have roles in cell migration, axon guidance and neurite growth; therefore duplication and divergence in the rhodopsin-like gene family may have played a key role in the evolution of cell type diversity (including the emergence of complex nervous systems) and in the evolution of metazoan body plan diversity. / Graduate

Three methods of communication were examined in the Middle Island tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae); defence behaviour, acoustic and chemosensory signalling. Previous studies had been limited to basic autecology and anecdotal evidence. This study was undertaken to understand the behaviours of this species to assist in conservation efforts. Defensive behaviours were elicited through repeated stimulation while aggressive behaviours were acquired through male-male battles. Femoro-abdominal stridulation was induced within both situations. Defensive stridulation functioned as alarm behaviour and was often accompanied by a visual display. Agonistic stridulation was executed by the eventual winner of combat. Aggressive battles were a progression of behavioural units of increasing risk on injury until an individual was determined the winner. Acoustic analysis was preformed on stridulations observed in aggressive and defensive behaviours. Stridulation was a broad band signal covering a range well above 16 kHz and possibly into the ultrasound range (>20 kHz). Two different forms of stridulation were identified; click train sound and hiss sound. High speed frame-by-frame analysis of stridulation and scanning electron micrographs of the abdomen and medial femur deciphered the mechanism and found the interaction of the cuticle to be unique among weta. Strikingly, micrographs also revealed two morphologies of abdominal projections; truncated ridges and columnar pegs. Both these points were not previously observed. Y-maze and partition tests were utilized for evidence of chemosensory signalling, while gas chromatography-mass spectrometry identified faecal volatiles in M. iisolata and 4 other weta species in a parallel study. Through partition experiments, evidence exists for a species-specific volatile pheromone and a sex-specific chemo-tactile pheromone. Dimethylsulphide, (CH3)2S, was present in the faeces of all 5 weta species, and may be produced by the individual.

Philosophiae Doctor - PhD / Tsetse flies are the biological vectors of human and animal trypanosomiasis and hence representant medical and veterinary importance. The sense of smell plays a significant role in tsetse and its ecological interaction, such as finding blood meal source, resting, and larvicidal sites and for mating. Tsetse olfactory behaviour can be exploited for their management; however, olfactory studies in tsetse flies are still fragmentary. Here in my PhD thesis, using scanning electron microscopy, electrophysiology, behaviour, bioinformatics and molecular biology techniques, I have investigated tsetse flies (Glossina fuscipes fuscipes) olfaction using behaviourally well studied odorants, tsetse repellent by comparing with attractant odour. Insect olfaction is mediated by olfactory sensory neurons (OSNs), located in olfactory sensilla, which are cuticular structures exposed to the environment through pore and create a platform for chemical communication.