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The Signal Monthly newsletter of the W. M. Keck Center for Behavioral Biology

at North Carolina State University November, 2015, vol. 17, no.3  

The Signal Wishes All Its Readers

This issue of The Signal contains the traditional Halloween Story

 

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Shuffling the Genome

by Samuel Widmayer

On October 28th, 2015, Genetics graduate student Chad Hunter successfully defended his doctoral dissertation, highlighting the genetic and environmental drivers of recombination rate variation in Drosophila melanogaster. Recombination is an essential biological process, ensuring proper chromosome segregation during meiosis and generating novel combinations of alleles within a chromosome. Chad emphasized that recombination rate is also an interesting complex molecular trait, varying widely between species, as well as between and within populations of the same species. Advised by Dr. Nadia Singh, Chad sought to understand how recombination rate variation in Drosophila is determined by genetics, environmental factors, and their interaction. Chad first illustrated a series of experiments he conducted exploring the role of environmental variation in shaping recombination rate variation in Drosophila. A previous study had shown that recombination rate varied across females with different genetic backgrounds, as well as across females of the same genetic background, but who were mated to males of different genetic backgrounds. Inspired by this finding, Chad asked whether there was a detectable interaction effect of male and female genetic background on recombination rate variation. To assess recombination rate in this system, Chad used a two-step crossing scheme. First, he crossed ten different strains of wild-type female flies to homozygous double mutants (y and v) to create female double heterozygotes. Second, each of these double heterozygote strains were crossed to wild-type males of the same ten strains. By counting the number of flies that exhibit one mutant phenotype and not the other, Chad was able to assess recombination rate variation in a diallel crossing design with 100 possible male-female combinations. Chad observed a significant effect of female genetic background, but not male genetic background or a male-female interaction, on recombination rate in this panel. Chad also highlighted work in the showing that recombination rate is driven by genetic

background, maternal age, and their interaction. Taken together, this portion of Chad’s defense summarized how the environment, in part, shapes recombination rate variation. Recombination rates vary at the population level, and through artificial selection experiments it has been shown that recombination rate is a heritable trait. However, Drosophila possess none of the few genes already known to affect recombination rate variation in other organisms. Together with Dr. Trudy Mackay and Dr. Wen Huang, Chad began to dissect the genetic architecture of recombination rate by conducting a genome-wide association study in the Drosophila melanogaster Genetic Reference Panel and utilizing a similar two-step crossing scheme as described before. Chad discovered that on Chromosomes (Chr) 3R and X, recombination rate had a broad-sense heritability (H2) of 0.12 and 0.41, respectively. However, the recombination rates on these chromosomes were independent, indicating that recombination rate might be regulated differently in these two locations in the genome. Further, the presence of Wolbachia infection in these flies corresponded to significantly higher recombination rates. The effect of Wolbachia infection status on recombination rate in Drosophila has never been reported before. Chad observed numerous genetic variants on Chr 3R and Chr X significantly associated with recombination rate variation. Additionally, a number of candidate genes with the largest effects on recombination rate variation were not found on Chr 3R or X, indicating a large role of trans-regulation of recombination. In the final portion of his defense, he gave an overview of how the effects of these genes were functionally validated. Chad found that many of these candidate genes carried significant individual effects on recombination rate using a similar two-step crossing scheme, only this time using RNAi-, P-element insertion, or deletion mutants in concert with the other phenotypic markers. Chad also showed through quantitative reverse-transcriptase PCR that many of these candidate genes show allele-specific expression differences in the ovaries of these flies. Congratulations, Dr. Hunter!

 

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A Bite in the House is Worth Two in the Bush by Megan Fritz

On October 5th, 2015, the W. M. Keck Center for Behavioral Biology hosted Dr. Carolyn McBride of Princeton University. McBride's research integrates techniques from evolutionary biology and neuroscience to elucidate the molecular basis for host specialization in the mosquito, Aedes aegypti. Her seminar was entitled “Molecular insights into the evolution of mosquito preference of human odor”. McBride opened her seminar by discussing the relevance of Ae. aegypti to global health. This mosquito is broadly distributed throughout the tropics, and vectors Dengue, Yellow Fever, and Chikungunya viruses. In many parts of the world Ae. aegypti is 'domesticated', breeding in human dwellings and blood-feeding upon humans. Because of their specialized lifestyle, the bite of this mosquito is particularly efficient at transmitting disease-causing viruses between humans. To shed light on the molecular basis for the specialized feeding behaviors of Ae. aegypti, McBride went to Kenya. She collected Ae. aegypti from indoor and outdoor sites to confirm reports (made 35 years prior) of an ancestral, forest-dwelling population, that existed in close proximity to the human-biting 'domestic' form. She first demonstrated that populations collected outdoors tended to have both the diagnostic coloration patterns and preference for animal hosts (guinea pig and chicken) as those previously reported for the forest-dwelling form. Populations collected indoors tended to prefer humans in host choice assays, indicating they were of the 'domestic' form. While mosquitoes use a variety of cues (warmth, CO2, visual cues, host-specific odors, etc.) to

locate their hosts, it was unknown which of these were responsible for the divergent preferences of the 'domestic' and forest-dwelling Ae. aegypti. McBride assayed a subset of her newly-collected populations, standardizing all cues except for host-specific odors. She demonstrated that strong human preferences still persisted in her 'domestic'

Dr. Carolyn (Lindy) McBride populations, indicating that human odor cues were important for human preference in Ae. aegypti. To identify possible genes involved in human odor recognition, two representative populations - one strongly human-seeking, and one guinea pig-seeking - were crossed, and gene expression levels in the antennae of the most phenotypically divergent F2 progeny were compared. Of 14

differentially expressed genes found in both population-level comparisons and F2 progeny, two

were olfactory receptor genes. One of these olfactory receptors, AaegOR4, was upregulated in human-seeking mosquitoes and recognized sulcatone, a component of human odor. Upon examination of the AaegOR4 coding sequence, seven genetic variants were found across populations. Three were most commonly found in human-seeking populations. When AaegOR4 variants were expressed in empty olfactory neurons of Drosophila melanogaster, McBride showed that these same three alleles were among the most sensitive to sulcatone. When examined together, allele-specific expression and sensitivity to sulcatone accounted for 92% of the variation in differential inheritance of the AaegOR4 allele according to host preference. McBride's research provides compelling evidence for the role of AaegOR4 in determining Ae. aegypti human-seeking behaviors. Perhaps a more thorough understanding of the genetic factors involved in Ae. aegypti host preference will lead to innovations that interrupt vector-borne disease transmission.

 

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Tongue-eating Isopods at the Keck Center by Ashley Chin-Baarstad

Dr. Bronwyn Williams led an exciting social evening discussion on “the curious case of the tongue-eating isopod.” Williams is a recent hire at the North Carolina Museum of Natural Sciences. Starting in January as the Research Curator of Crustaceans, she recently transitioned to the Research Curator of Invertebrates (excluding mollusks). She came from a post-doc at Southern Illinois University, where she worked on crayfish and symbionts, looking at community evolution.

A colleague of Williams’s at the museum, the curator of fishes, shared with her a sample of a fish jaw containing an isopod and she brought that with her in a jar (pictured below). It turned out to be an example of a tongue-eating isopod and sparked Williams’s interest. There are 400 known species in this group of tongue-eating isopods, though this is likely only a fraction of the existing species. While not much is known about this group of isopods, examples often make it onto lists of “weirdest parasites.”

Isopods, Williams explained, are an order of crustaceans with segmented bodies and heads fused to the first shell segment. There are 11,000 known isopod species and they can vary in size, being as small as three-tenths of a millimeter to over a foot long. Most isopods are detritovores or scavengers and free living. Amongst isopods is a group of marine, obligate fish parasites.

Williams came prepared with handouts, one of six picture examples of tongue-eating isopods and one with the known global distribution of species and a proposed model of the lifecycle and development. The tongue-eating isopods are protandrous hermaphrodites, starting life in the water column with undetermined sex. Using a chemical cue from the desired host fish, they shoot up, hoping to land in the gills. Once there, they molt into a male. When another male arrives in the gills, the first or larger isopod will move into the mouth and become female.

Despite their name, they do not actually eat the tongue. They latch into the base of the tongue with their hook-like legs and suck the blood. Like leeches, they produce an anti-coagulant. Eventually the fish’s tongue atrophies and falls off. The isopod becomes the functional equivalent of

the tongue. It is unknown how much the isopod is depending on mucus versus blood for survival.

In examples that have been seen, the female appears to fill up the buccal cavity of the fish and have reduced eyes. This is the final host and stage for the isopod, whose lifespan is unknown. If something were to happen to the female, one of the two to five males often found in the gills would replace her. After a male mates with the female, the female will brood the young in her pouch and release the young from the mouth of the fish.

As a “benevolent” parasite, the isopod is interested in the fish’s survival. Although the host is kept alive, fish do show reduced fitness when being parasitized. Some fish have developed a mechanism to sterilize the male isopods. The isopod parasitizes every family of bony fishes, even piranhas. An interesting trend is that host specificity increases towards the tropics. So, when there are more host choices, the isopod appears to be more choosy.

Very little research has been done on these tongue-eating isopods. There has been some phylogenetic work using rRNA. It appears that this group is made of several genera and that this life history evolved once (is monophyletic). Overall, among parasitic isopods, there appears to be a march towards specialized parasitism, from more general positions on fish species and genera to more specificity in hosts and location on hosts.

Williams and her colleagues at the museum are interested in studying these isopods and would love to have more examples. So, if you are ever fishing and find one, Williams would welcome samples.

Fish jaw with a tongue-eating isopod attached

 

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THE LATE DR. LEONARDO

by Robert Anholt “And then he told me that he doesn't treat MONGRELS! Can you believe that!” “I can understand your aggravation, Mrs. Myrtle,” Dr. Valentine replied, “He is, shall we say, somewhat eccentric and perhaps not always tactful, but I assure you that he is a highly respected, first-rate veterinary surgeon.” “There was no need for him to be so abrasive and rude.” Mrs. Myrtle insisted. “Besides Tiffy is not a mongrel; she is a registered pure-bred Dachshund!” “And a very nice one, indeed,” Dr. Valentine said soothingly, “and the good news is, Mrs. Myrtle, that she will be absolutely fine after a few shots of penicillin. It's simply a common form of laryngitis. Nothing to worry about. Please take her down, Janice.” Janice lifted the little Dachshund from the table and handed her to Mrs. Myrtle. Dr. Valentine had become dependent on his capable assistant for lifting and restraining animals ever since the unfortunate accident a year earlier, which had severed his right hand. No one knew the details of his tragedy and he refused to discuss it. “He really sounds like a monster.” Janice remarked after Mrs. Myrtle had left. “Did you really mean that? About him being such a great veterinary surgeon and all that stuff?” “Indeed, Janice, indeed,” Valentine said. “We can not always judge a person's professional capabilities from superficial flaws in his personality. Dr. Leonardo, beyond doubt, is one of the most talented veterinarians in our state, perhaps even in the country or, for that matter, in the world. Unfortunately, he has chosen to become a somewhat unconventional recluse practicing an unusual branch of veterinary medicine for which there is, at least in our district, very little demand. Of course, his abrupt and arrogant demeanor does not help his popularity. Yet, as a professional I have the greatest respect for him.” Dr. Leonardo’s clinic provided a stark contrast to the hustle and bustle of Dr. Valentine's well-organized veterinary hospital. It had been several years since his small waiting room had seen its last patient. The pages of a New York Times had turned yellow and an issue of Vogue magazine laid open on the little table at the page its reader had perused three years earlier. Dr. Leonardo’s examination room was

gathering dust and spider webs. Needless to say, he did not employ a veterinary assistant. How could such a brilliant veterinarian, as judged from Dr. Valentine’s description, be near the brink of bankruptcy? The reason was the “unusual branch of veterinary medicine”, to which Valentine had referred. Dr. Leonardo specialized in the treatment of exotic animals and, as a matter of principle, refused to treat ordinary, run-of-the-mill dogs or cats. After Dr. Leonardo had obtained his veterinary license he had gone to Central Africa, where he completed his doctoral dissertation on arthritic hock degeneration in wildebeests. His work was considered a classic by the Veterinary Association of Central Africa, which had awarded him the coveted Golden Aardvark Medal. He had remained in Africa for twenty years and written several important articles on topics such as nasal amputation for the treatment of rhinitis in the white rhinoceros, the risk of whiplash in short-necked giraffes, and the benefits of spot removal from hyenas. However, his numerous publications had failed to elicit the worldwide recognition and admiration they deserved. Disillusioned and demoralized, Dr. Leonardo, D.V.M., Ph.D. had returned to the United States and established a modest veterinary clinic in a small, rural community in Nebraska. But he had made one unshakable resolution: he would never lower himself to the treatment of ordinary diseases of mundane pets and farm animals; he, the Great Leonardo, the Grand Veterinary Guru of Central Africa, would henceforth treat only rare disorders in exotic animals. That fateful January night, as ice and snow flurries decorated the bleak Nebraska winter landscape, Dr. Leonardo received what would be his last telephone call. “Leonardo's Veterinary Clinic,” he answered. “Dr. Leonardo?” a female voice enquired. “Thank God you’re in! My name is Susan Stubble and I have an emergency! Nellie appears to be not well, doctor. Would it be possible for you to come and see her?” “I am, sorry, ma’am,” Dr. Leonardo replied, “I treat only exotic animals. For cats, dogs, and other ordinary pets you should call Dr. Valentine. I’ll give you his number.” “We already called Dr. Valentine, but he said that he was short-handed tonight,” Mrs. Stubble replied. “Besides, Nellie is quite exotic. She is our pet crocodile.” The patient’s description immediately sparked Dr. Leonardo’s interest! A pet crocodile! It was the professional opportunity he had waited for! Not just an angora cat or a Shar Pei dog, for which he had

 

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occasionally made exceptions in times of extreme financial distress, but a true, live, honest-to-goodness exotic animal! One that was sick, one that needed HIS immediate medical attention! “I’ll be right over, Mrs. Stubble,” he said. “Whatever you do, don’t move the patient and keep her warm.” After these words of sound advice, he donned his heavy fur coat, stepped into his cotton-lined boots, put on his wool hat and warm leather gloves and braced himself for a long trip through the icy winter frost. That evening a cold, eerie glow shrouded the landscape. The bright pale moon and the shimmering stars were the only witnesses to Dr. Leonardo’s trip as his small truck plodded on snow tires through the frost-covered country roads, on its way to the isolated farmhouse of George and Susan Stubble. The old brick farmhouse stood at the end of a long, deserted prairie road. While Dr. Leonardo’s truck pulled into the slick and windy yard, Susan Stubble watched his arrival from behind her window. As the vet stepped out of his sputtering, exhausted vehicle, she opened the front door and welcomed him exuberantly. “O, Doctor, we are so glad you are here! We are worried about Nellie! She has never behaved like this! I can’t remember the last time this happened. Can you, George?” “Well,” George replied, “something similar happened about a year ago, dear, when Dr. Valentine came out. Remember, when Nellie.....” “But she wasn't as bad then as she is now, George,” Mrs. Stubble interrupted. “O, Doctor, bless you for coming out in this horrible weather!” “Let’s discuss the patient, Mrs. Stubble,” Dr. Leonardo prodded. He had taken an immediate dislike to the short, heavy woman with the rosy cheeks, and to her sickly-looking tall, skinny husband with his metal-framed bifocals. “What’s wrong with Nellie and how did you get a pet crocodile in the first place?” “George found her on his trip to Brazil, didn’t you, George? He was in the forestry service in South America for almost eight years, weren’t you, George? He found Nellie when she was still in the egg, near the banks of one of the Amazon tributaries, didn’t you, George? He never thought the egg would actually hatch, did you, George? And, then, right after he had brought it home, right here in Nebraska, right here in this house, the shell cracked and out came Nellie! O, Doctor, you should have seen her! She was so cute, she fit in the palm of your hand. The loveliest little thing you’ve ever seen, wasn’t she,

George? We love her to death, Doctor, don’t we, George? She is now four years old and we think that she’s VERY SICK, don’t we, George? You see, Doctor, normally she moves around and eats her food immediately. We feed her twice a week, don’t we, George? Chicken. And she always eats her chicken right away. But the last two days she has not moved at all and hasn’t touched her food. O, Doctor, could it be that she is.....” Mrs. Stubble burst into tears, putting her arms around the neck of her taciturn husband, who had supported her account with nods at the appropriate moments. “Please, pull yourself together, Mrs. Stubble,” Dr. Leonardo said without the slightest sympathy. “Where is the patient, anyway?” “This way, Doctor.” Susan Stubble led him through a long, cold corridor to a bolted wooden door. She opened the padlock, undid the chain and slid the bolt sideways. As the door creaked open, an unhealthy, musty stench greeted the Stubbles and their visitor. George flicked a light switch and Dr. Leonardo found himself in a small room containing an old metal bed with a torn, soiled mattress and a broken wooden table. The room had no windows and was not heated. Dried white and black reptilian excrements covered the carpet. Two large, brown chickens paraded nervously around the table. “You see, Doctor,” Mrs. Stubble said, pointing at the chickens, ”she hasn’t eaten in days.” “But where is she, Mrs. Stubble?” Dr. Leonardo asked somewhat perplexed by the unconventional scenery. “She is usually under the bed, Doctor. It’s her favorite spot, isn’t it, George?” “That’s right,” George concurred, “and she hasn’t moved in days. I poked her with a broomstick and no response whatsoever.” After this brief, emphatic statement he fell silent like a confident prosecuting attorney resting his case. Dr. Leonardo squatted down and, choosing a relatively unsoiled spot, placed his hands on the frozen carpet. He bent down to look underneath the bed and saw an approximately eight-foot-long crocodile, its scaled green tail neatly curled up underneath the mattress. The creature was immobile. “We’ll have to get her out from underneath the bed, Mrs. Stubble,” Dr. Leonardo informed his worried client. George obligingly took a broomstick and poked at Nellie under the bed. Dr. Leonardo watched as the end of the stick dented the pliable reptilian skin. There was no response. The two chickens cackled and fluttered around the room.

 

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“O, Doctor, is she alive?” Susan asked with panic in her voice. “Please, be quiet, Mrs. Stubble.” he said with irritation. “Mr. Stubble, let’s move the bed.” Each man took hold of one end of the bed. They lifted it and carried it across the room, exposing Nellie in all her glory. She lay pressed against the wall. Her tail was curled up against the corner of the room and her long snout rested flat on the ground. Dr. Leonardo opened his case and took out a stethoscope. With a flamboyant gesture of artistic professionalism he swung the instrument around his neck, placed the earpieces into his ears and pressed the end of the stethoscope against Nellie’s skin, behind her front paws. The earnest expression on his face made it clear to his observers that he needed absolute concentration and George and Susan Stubble stood immobile and breathless. After a few minutes of intense listening, he moved the end of the stethoscope to the center of Nellie’s back behind her snout. “A very unusual case,” he announced gravely as he took the earpieces out and let the stethoscope dangle around his neck. His cryptic statement was designed to hide the fact that he could hear no sound in his stethoscope, and that he was at a loss about how to proceed. “Is she alive, Doctor?” Susan asked timidly, but with a glimmer of hope. “Whether she is permanently dormant or only temporarily in remiss is indeed a critical concern,” Dr. Leonardo enlightened Nellie’s owners. “I shall have to examine the patient’s epiglottis and the coloration of her larynx.” “Does that mean that there is hope, Doctor?” Susan asked with suppressed jubilation. “O, wouldn’t that be wonderful, George? It would be such a relief!” “Please, Mrs. Stubble, do not distract my attention with your idle chatter,” Dr. Leonardo said sternly like a schoolmaster reprimanding an unruly pupil. “Mr. Stubble, please, help me slide the patient to the center of the room.” George grabbed Nellie’s tail and pulled while Dr. Leonardo bent over and pushed with his hands

around her opposite flank. The massive reptile slid across the carpet like a stiff surfboard without showing any signs of life. Dr. Leonardo found himself in a quandary. Should he, after waiting all these years for a sick exotic animal, admit that he had no clue of what was wrong with Nellie? Should He, the Great Leonardo, Recipient of the Golden Aardvark Medal, confess that he could not determine whether the animal was dead or alive? Would that not make him the laughing stock of the entire veterinary community? At least, he would have to decide whether the creature was deceased or simply lethargic. Certainly it showed no signs of life, but there were no signs of decay, either. Perhaps the color of the larynx would give him a clue as to whether his patient was decomposing or simply hibernating. He rummaged in his bag and found a small flashlight. Holding it in his left hand, he knelt in front of the animal, pried open her snout, placing his left hand with the flashlight on her lower jaw and pushing the upper jaw upward with his right hand. He needed all his force to open Nellie’s muscular, sinewy upper jaw. With sweat on his brow and his right hand quivering from the effort, he finally gazed into the crocodile’s enormous mouth. He placed his left knee on the lower jaw to free his left hand and with his flashlight illuminated his patient’s inner depths. In the dimly lit room, it was difficult for him to observe the epiglottis with his little flashlight. He moved his head forward between the reptile’s jaws as far as he could. At that moment Susan Stubble noticed an alarming development. Nellie’s eyelid slowly opened, revealing a cold-blooded angry crocodile eye. The eyeball rolled down and forward in its socket fixing its glare on the space between its open jaws. “Dr. Leonardo....” Susan said with agitation, “Dr. Leonardo.....” But the doctor was sick and tired of her unsolicited interruptions and put her firmly in her place with these ill-fated words: “Be patient, Mrs. Stubble, I’ll be finished in a snap!”

 

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Honeybee Transgenesis and Genome Editing

by Hongmei Li-Byarlay

On May 31st, 2015, I arrived at the Heinrich Heine University of Düsseldorf, Germany to attend a 2-week workshop of honeybee evolutionary genetics and embryonic technologies. The purpose of this training was to provide a solid foundation of knowledge on honeybee embryonic injections, special techniques on transgenesis of honeybees using the Piggyback transposon system, and applications in honeybee genome manipulation. The course had a format of integrating lectures and field experiments given by Dr. Martin Beye, Dr. Christina Vleurinck, and Dr. Marianne Otte. Main topics covered in the lectures were the development of honeybee (Apis mellifera) embryos and theory of genome editing using CRISPR/Cas9 or Piggybac transposons, and related molecular tools. The practical aspects of insect genetic technology were divided into two main themes: delivery of technologies and gene editing. Because injection is the preferred method to deliver insect transgenes into germ lines, I spent a few days to learn everything about embryo microinjection. The procedure was demonstrated by Dr. Christina Vleurinck, who provided useful tips about different aspects of injection procedures, including sample preparation and collection before injection, handling embryo samples, and post-injection procedures. I also spent time preparing my own single-guided RNA by PCRs. The second week I was able to inject test constructs of my interest, and collected larvae for further genotyping analysis. I enjoyed long but productive days during the workshop, and interactions with other working staff, learning tips on experiments, RNA design, and suggestions on the development of my future research. Of course, outstanding German beer and tasty food was the additional bonus of this workshop.

This experience was made possible through a Vandenbergh Travel Award from the Keck Center. I greatly appreciate the Keck Center and Army Research Lab for enabling me to attend this fruitful workshop. Now that I have learned the necessary skills for honeybee genome editing, I can apply them to my current project and test novel hypotheses.  

Seminars

On November 4, 3:30 pm, Dr. Thomas E. Finger from the Rocky Mountain Smell and Taste Center and the Department of Cell and Developmental Biology at the University of Colorado, Aurora, CO will present the Allen Distinguished Microscopy lecture, titled “3D Reconstructions of Taste Buds Ultrastructure Show Chemical Synapses Lacking Synaptic Vesicles.” The seminar will be in 3503 Thomas Hall. On November 12, 3:30 pm, Dr. Harold Zakon from the Department of Neuroscience at the University of Texas at Austin will present a seminar titled “Electric Fish in the Genomic Age: Testing for Parallel Molecular Evolution.” The seminar will be in 101 David Clark Laboratories. At 7:00 pm, Dr. Zakon will present a Science Café talk in the North Carolina Museum of Natural Sciences, Daily Planet Theater, Nature Research Center, 121 West Jones Street, Raleigh, NC 27601. The title is "The Amazing World of Electric Fish!" On December 7, 1:30 pm, Dr. Nancy A. Moran from the Department of Integrative Biology at the University of Texas at Austin will present a seminar, titled “Bugs in the Bees (the Gut Microbiota of Social Bees).” The seminar will be in 3503 Thomas Hall.

 

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Publications

The following publications from the W. M. Keck Center for Behavioral Biology have appeared in print: Ponnusamy, L., Schal, C., Wesson, D. M., Arellano, C. and Apperson, C. S. (2015) Oviposition responses of Aedes mosquitoes to bacterial isolates from attractive bamboo infusions. Parasit. Vectors 8: 486. Jensen, K., Schal ,C. and Silverman, J. (2015) Suboptimal nutrient balancing despite dietary choice in glucose-averse German cockroaches, Blattella germanica. J. Insect Physiol. 81: 42-47. Barberán, A., Dunn, R. R., Reich, B. J., Pacifici, K., Laber, E. B., Menninger, H. L., Morton, J. M., Henley, J. B., Leff, J. W., Miller, S. L. and Fierer, N. (2015) The ecology of microscopic life in household dust. Proc. Biol. Sci. 7: 282. Sørenson, P., de los Campos, G., Morgante, F., Mackay, T. F. C. and Sorensen, D. (2015) Genetic control of environmental variation of two quantitative traits of Drosophila melanogaster revealed by whole-genome sequencing. Genetics 201: 487-497. Morozova, T. V., Huang, W., Pray, V. A., Whitham, T., Anholt, R. R. H. and Mackay, T. F. C. (2015) Poly-morphisms in early neurodevelopmental genes affect natural variation in alcohol sensitivity in adult Drosophila. BMC Genomics 16: 865.

Of note…

Trudy Mackay delivered the John A. Lynch lecture at the College of Science at Notre Dame University, South Bend, IN. She also gave a seminar in the Department of Genetics and Biochemistry at Clemson University (Clemson, SC). Heather Patisaul gave a talk at the Kansas University Medical College, entitled “Brain chemistry: Endocrine disruption of neuroendocrine pathways and behaviors.” She also gave a talk at the National Toxicology Program at the National Institute for Environmental Health Sciences, entitled Genes, environment, brain and behavior: Endocrine disruption of the developing brain.”

The W. M. Keck Center for Behavioral Biology gratefully acknowledges support from our sponsor BASF. Inc.

Visit our website: http://keck.sciences.ncsu.edu

To contribute to The Signal, to be placed on our mailing list or for information about the W. M. Keck Center for Behavioral Biology, contact Dr. Robert Anholt, Department of Biological Sciences, Box 7614, North Carolina State University, Raleigh, NC 27695-7614, tel. (919) 515-1173, anholt@ncsu.edu.