Selection Committee for the 2016 Academic Awards and Other Honors (Held on May 21, 2016)
Koji Akasaka, Takahiro Asami, Hiroshi Iida, Taisen Iguchi, Shigeru Kuratani, Kenji Tomioka, Toshiya Matsushima
Chairperson Taisen Iguchi
All six applicants for this award met the condition set forth in the selection regulations of being "young researchers conducting active research who are strongly expected to make future progress and development," resulting in a high-standard selection process. As a result of detailed deliberations regarding the applicants' research content, research achievements, and future potential, the following three individuals (in Japanese syllabary order) were decided to be recommended to the Board of Directors.
2016 Zoological Society of Japan Award for Encouragement
Taketoshi Kiya
Associate Professor, Division of Biology, Department of Natural System, Institute of Science and Engineering, Kanazawa University
Research Topic: Elucidation of the neural basis of innate insect behavior using activity-dependent gene expression
Reasons for the Recommendation
Member Tsuyoshi Kiya is conducting research aimed at elucidating the neural mechanisms controlling insect behavior using molecular biology techniques. Particularly noteworthy is his research in identifying the immediate-early genes kakusei and Hr38, which are expressed dependently on neural activity in honeybees and silkmoths, respectively, and developing a method to visualize active neurons using them. Member Kiya has achieved outstanding results using this method, such as identifying the brain regions active during the waggle dance in honeybees and revealing that their neural activity depends on visual experience during foraging flights, as well as comprehensively clarifying the male brain regions responding to female pheromones in silkmoths and Drosophila. Member Kiya's research, which approaches behavioral mechanisms by developing novel experimental techniques, is highly commendable and holds great promise for future development.
Winner Summary
It is a great honor and pleasure to receive this prestigious award. Taking this valuable opportunity, I would like to introduce the research I have conducted thus far and my future direction.
Insects exhibit a variety of fascinating behaviors and many of these behaviors are hard-wired. From childhood, I have been strongly interested in instinctive behaviors of animals and wanted to figure out why animals can behave appropriately without being taught from others. Out of many animals, insects drew my interest most strongly, since they can perform highly ordered behaviors even with such tiny brains. Since I first had the opportunity to address my hard-wired questions as a graduate student, I am luckily pursuing my interest as a researcher.
Aiming to elucidate the neural basis of instinctive behaviors in insects, I focused on immediate early genes (IEGs), whose expression increases in response to neural activity, as markers of neural activity. To date, I have identified two novel IEGs from insect brains that can be reliably used as neural activity markers and have comprehensively mapped active neurons in the brains of insects exhibiting instinctive behaviors, as described below.
- Identification of a brain region related to foraging and dancing behavior in the honeybee, utilizing a novel IEG awakening.
- Identification of a conserved IEGHr38and visualization of neurons activated by sex pheromones and courtship behavior in fly and silkmoth.
Here, I briefly summarize each study.
1. Workers of honeybees (here I studied European honeybees) are able to transmit the location of rich food sources which they found during their foraging trips by exhibiting dance behavior. This behavior is well-known as “dance communication” of honeybees. In dance communication, foragers transmit information of ‘distance’ and ‘direction’ of food sources by ‘waggle duration’ and ‘angle’ of dances. Nestmates follow the dance in the dark hive, decode dance information, and reach the indicated food sources, which are sometimes several kilometers away from the hive. Although this highly sophisticated behavior long drew interest of researchers, the neural mechanism of dance communication was totally unknown. To understand the neural mechanism of dance communication, I thought that it is essential to know the active brain regions and neurons in dancers. To identify active brain regions in dancers, I came to the idea to use IEGs as a neural activity marker. Since no IEG was known in insects, I screened for genes upregulated upon neural activity and identified a novel IEG awakeningfrom honeybee brains. Establishing neural activity mapping methods utilizing awakening, I discovered that a subtype of mushroom body neurons is preferentially active in dancers. Further examinations revealed that the activity is related to foraging experience and visual inputs during foraging. This study for the first time identified an IEG from insect brains and revealed a candidate brain region related to dance communication. What role do these mushroom body neurons play in dance communication? This question remains unsolved. In the future study, I would like to reveal the neural circuit and its working principal that govern dance communication ability of honeybees.
2. Instinctive behaviors of insects are so diverse and all species have their own unique behaviors. As an entomologist, it is a dream to establish a method that is useful to detect active neurons in any insect that one wants to investigate. From silkmoth brain, I identified a highly conserved IEG Hr38and confirmed that Hr38can reliably be used as a neural activity marker in silkmoth, fly, and honeybee. Using Hr38, I revealed the comprehensive neural activity pattern of a male silkmoth stimulated with sex pheromone and a male fly stimulated with females. Hr38is the first conserved IEG in insects to be reported. Since Hr38is conserved among metazoans and in situ Hybridization is applicable to any animals., Hr38 can serve as a neural activity marker when identifying brain regions and neurons active during instinctive behaviors. Utilizing transgenic techniques in silkmoths and flies, I am currently establishing activity-dependent neural tracing methods where neurons activated by specific behaviors can be visualized with GFP and artificially controlled via optogenetics. Using these novel methods, I aim to identify and uncover the functions of new neural circuits underlying instinctive behaviors in insects in future studies.
Finally, I would like to express my deepest gratitude to all of my advisors, collaborators, and family. These works were not at all possible without their help.
Jun Sato
Fukuyama University, Faculty of Life Sciences, Department of Biotechnology, Associate Professor
Research topic: "Elucidation of mammalian molecular phylogeny and the origin of Japanese mammals"
Reasons for the Recommendation
Member Jun Sato has promoted molecular phylogenetic research on mammals, such as the phylogenetic positions of red pandas and pinnipeds (seals, sea lions, walruses), which had been long-standing mysteries, as well as the phylogenetic positions of the Ryukyu Islands' endemic spiny rats, and Japan's endemic field mice and Japanese dormice. At the same/same time, he developed phylogeographical research on mustelids such as sables and Japanese martens, clarifying that geological and ecological factors played major roles in the formation of the Japanese mustelid fauna. Furthermore, by evaluating the genetic uniqueness and diversity of mammals inhabiting the Japanese archipelago—specifically targeting the spiny rats of the Ryukyu Archipelago, the Tsushima marten of Tsushima, the sables of Hokkaido, and the Japanese dormouse—he evaluated the extinction risks of organism populations isolated on islands, thereby contributing to mammalian conservation genetics as well. In addition, Member Jun Sato conducted research on the recombination of the hemoglobin beta-chain gene associated with intersubspecific hybridization of wild mice and research on polymorphisms in mammal coat color-related genes. He also discovered that the umami taste receptor gene in pinnipeds has become a pseudogene, and published interesting results indicating that dietary habits and feeding behavior were involved in this pseudogene formation, thereby contributing to the field of mammalian molecular evolutionary science as well. In addition, anticipating his future development, we determined that Member Jun Sato is a fitting recipient of the Zoological Society of Japan Award for Young Scientists.
Winner Summary
I find the fascination of my research in exploring the information left in genomes regarding the past, present, and future of living organisms. Up to now, using four approaches based on genetic information—molecular phylogenetics, molecular evolution, phylogeography, and conservation genetics—I have conducted research aimed at understanding the origins, environmental adaptation, and extinction risks of mammals.
In molecular phylogenetic studies, phylogenetic estimation using multiple nuclear DNA has revealed the long-standing mystery of the red panda (Red panda), Pinnipedia (seals, sea lions, walruses), Cuban solenodon (Cuban solenodon), spiny rat (Tokudaia), as well as elucidating their phylogenetic placement and origin timing, and clarifying the correlation between the phylogenetic radiation of the family Mustelidae, global environmental change, and Earth history.
In molecular evolutionary studies, wild mice (house mouse, I conducted research on the recombination of the hemoglobin beta-chain gene resulting from intersubspecific hybridization, as well as the evolution of coat color-related genes and taste receptor genes in carnivorous mammals (Carnivora). Particularly in the research on taste receptor genes, I discovered that the umami taste receptor gene in pinnipeds has become a pseudogene, and demonstrated that diet and feeding behavior were involved in the pseudogenization of this gene.
In phylogeographic studies, the sable (sable) or Japanese marten (Martes melampus, we estimated the migration routes and periods of entry into the Japanese archipelago. By combining these results, we recently summarized research on the molecular phylogenetics and phylogeography of 63 Japanese terrestrial mammal species. Through large-scale comparative phylogeographic analysis, we clarified that historical geological changes in the Tsugaru, Tsushima, and Korea Straits, as well as phylogenetic relatedness reflecting differences in niches, have had a major impact on the distribution formation (sympatry and allopatry) of Japanese terrestrial mammals.
In conservation genetics research, we are studying the effects of forest fragmentation caused by artificial structures on the genetic diversity of wildlife populations, as well as researching extinction risks using island mammals as models. It is said that extinctions have occurred most frequently on islands so far, and one suspected factor is the decrease in genetic diversity due to the reduction of island populations into small populations. Therefore, evaluating the genetic uniqueness and diversity of insular populations is important for gaining insights into extinction risk. So far, Ryukyu spiny rats and Tsushima martens (Tsushima marten) and others, we have clarified the high phylogenetic uniqueness of island lineages through multi-locus molecular phylogenetic analyses. In addition, we revealed that the Tsushima marten and Hokkaido sable exhibit significantly lower genetic diversity compared to mainland and Eurasian continental populations, respectively. Currently, taking advantage of Fukuyama University's geographical location, we are conducting research on the genetic diversity of insular biological populations using the wood mouse populations on the islands of the Seto Inland Sea as a model. Among these findings, we discovered that the genetic diversity of mitochondrial DNA shows a positive correlation with island area. This suggests that a reduction in population size has caused a decline in the genetic diversity of island populations.
Against the background of the research based on the above four pillars, I am currently conducting dietary analysis of mammals using the DNA barcoding method. The purpose is to obtain insights into the environmental adaptation of mammals and to identify the ecological factors that significantly influenced the determination of distributional sympatry and allopatry as described above. In addition, I believe this will provide ecologically important insights for conservation biology, as it can contribute to elucidating food webs in ecosystems. Furthermore, elucidating dietary habits is of great interest from the perspective of correlation with polymorphisms in the aforementioned bitter taste receptor genes. In both the oral and poster presentations, I would like to introduce my mammalian research focusing on the above four pillars.
Masato Nikaido
Associate Professor, Department of Life Science and Technology, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology
Research topic: Elucidation of the molecular mechanisms involved in the acquisition of vertebrate diversity
Reasons for the Recommendation
Member Masato Nikaido has consistently explored vertebrate phylogenetic relationships and adaptive evolution mechanisms at the DNA level. His achievements have prompted revisions in textbooks and illustrated encyclopedias, thereby becoming widely known to the public. First, based on insertion patterns of short interspersed nuclear elements (SINEs), Member Nikaido discovered that hippopotamuses are the extant species most closely related to whales, and subsequently reported a series of important findings regarding the phylogenetic positions of many mammals. Furthermore, focusing on East African cichlids, Member Nikaido demonstrated that pheromone receptor genes underwent strong natural selection in the past. In view of his series of research achievements clarifying the genetic background of biodiversity, as well as expectations for future developments, we have determined that Member Masato Nikaido is a worthy recipient of the Zoological Society of Japan Encouragement Award.
Winner Summary
Since beginning my research in 1997, I have focused on the adaptive evolution of animals. In particular, the mechanisms of morphological diversification in higher vertebrates through adaptive evolution are of primary interest to me, as the Earth is filled with creatures that are fascinating in terms of their appearance (phenotypes). The goal of my research is to link these fascinating phenotypes to genotypes by applying Darwin's theory of natural selection at the DNA level.
Around 2000, I published several important papers on the molecular phylogeny of mammals: 1. the phylogenetic position of hippopotamuses (Nikaido et al. 1999), 2. the monophyly of toothed whales (Nikaido et al. 2001), and 3. the phylogenetic relationship of bats within mammals (Nikaido et al. 2000). These studies attracted the attention of many biologists, including paleontologists, and have been widely cited in scientific journals. In particular, my discovery of the close relationship between hippopotamuses and whales challenged two traditional hypotheses: “the monophyly of the order Artiodactyla” and “the monophyly of mesonychians and whales.” Today, both of these hypotheses have been revised, and the new order “Cetartiodactyla” has been proposed based on my findings. Around 2007, I shifted my research focus to the evolution of coelacanths and cichlids (groups that are also very important in the field of evolutionary biology as textbook examples of a living fossil and adaptive radiation, respectively). For both animals, I participated in whole-genome sequencing and comparative genomics projects (Nikaido et al. 2013; Brawand et al. 2014). Based on comparative genomics, I discovered a genetically distinct coelacanth population off the northern coast of Tanzania (Nikaido et al. 2011). The coelacanth genome project also shed light on the evolutionary mechanisms of the water-to-land transition in vertebrates at the DNA level. Comparative genome analyses, including pheromone receptor genes (Nikaido et al. 2014), revealed that a considerable amount of standing genetic variation (ancestral polymorphisms) exists in cichlid genomes, which could drive adaptive radiation.
Currently, I focus on the genomic region responsible for the parallel evolution of adaptive morphology (such as lip thickness) in cichlids. Specifically, I performed a comprehensive QTL mapping analysis using more than 400 hybrid individuals, which led to the identification of the candidate gene (genomic region) responsible for lip thickness. I hope this study (along with my previous research) will become a landmark paper for understanding phenotypic evolution from the genotype. Let's enjoy evolution.
