Susan C.P. Renn - US grants

[unreadable] DESCRIPTION (provided by applicant): The relationship between sex and behavior is a persistent question from society, as well as the medical and the research communities. Neuroscience research has undeniably demonstrated that the genetic sex of an individual has broad ranging effects on both anatomical brain areas and behaviors. However, a parallel line of research has demonstrated the inaccuracy of predicting phenotype based solely on genome sequence, thus implicating environmental influence. I propose to contrast the mechanisms that underlie genetic and environmental influences on gender biased behaviors using a pair-bonded monogamous animal model of parental care, genus Julidochromis, African cichlid fishes. I take a "systems biology" approach that quantitatively integrates phenotype data from multiple levels including neural gene expression, hormone titers, and behavioral observations. The African Cichlid fishes provide a unique opportunity to observe naturalistic behaviors in which gender-biased behaviors can be reversed by either environmental effects or genetic effects. The behavioral phenotypes, hormone levels, and gene expression profiles can therefore be assessed in these three paradigms 1) conventional gender-role 2) environmental reversal 3) genetic reversal. Within the conventional gender-bias paradigm the males are larger, more aggressive and territorial, while the females provide the egg care and nest maintenance. In this same species, altering the social environment, will reverse gender-biased behaviors, while in a closely related species the gender-biased behaviors are reversed by genetic background. Covariance analysis across multiple levels of phenotype will identify molecular modules that correlate with gender biased behaviors independent of sex. Paradigm 1 will be used as baseline from which to measure and contrast the two reversal phenotypes, and the molecular modules that are recruited in paradigms 2 & 3 will be contrasted in order to evaluate the mechanisms that underlie environmental and genetic influence. The localization of gender-biased neuronal gene expression will indicate neuroanatomical sites for regulation of these behaviors and thus lay the foundation for a model system in which to address the relationship of neural and molecular networks that orchestrate plastic and biased gender-role behavior. PUBLIC HEALTH RELEVANCE The great influence of sex on the brain is undeniable at the level of neuroanatomy, neurochemistry, brain function, and even behavior. The proposed systems level research integrates data from behavioral, physiological and molecular level in order to contrast mechanisms by which genes and the environment influence gender-biased behaviors and identify neuroanatomical sites important for the regulation of these behaviors. I use an animal model (cichlid fish) to study complex social behaviors that are directly relevant to the broad range of normal sex-related differences in human social behaviors as well as psychiatric conditions that show both genetic and environmental components. [unreadable] [unreadable] [unreadable]

In all animals, aggression is a complex social behavior with multiple causes and manifestations. Growing evidence suggests that different mechanisms underlie different forms of aggression. This project examines different forms of aggression in the African cichlid fish Astatotilapia burtoni. Aggression in males of this species is associated with territoriality and is regulated by social factors and testosterone. Previous research has identified brain regions, physiological mechanisms and patterns of gene expression that underlie the variety of aggression levels in males. Laboratory stock females do not care for their young nor do they show stereotypical forms of aggression. However, aggression can be induced in the laboratory through manipulation of the social environment. This form of female aggression, as in males, is associated with elevated testosterone levels. Recent observations of a newly acquired wild stock reveal a "good mother" phenotype that includes defensive aggression to protect free-swimming fry. This new stock will allow a comparison of different hormone levels correlated with different levels of maternal aggression. Furthermore, the availability of genomic tools for this species (a cDNA microarray) will allow the identification of gene expression associated with maternal aggression. The pattern of gene expression can be then compared between natural maternal aggression, induced female aggression and territorial male aggression. This work will answer questions regarding the extent of overlap between the gene sets that regulate each of these forms of aggression and will identify specific subsets of the gene expression pattern that are uniquely associated with male, female, and/or maternal forms of aggression. Through collaboration between the Renn Lab in the biology department and the Jones team in the math department, undergraduates at Reed College will engage in cutting edge genomic research and rigorous statistical analysis of datasets incorporating measures of behavior, physiology and gene expression.

Gene duplication and the subsequent evolution of the duplicates is an important source of genetic and functional novelty in all three domains of life. As the African cichlid fishes have undergone rapid, recent and repeated speciation events, they constitute an ideal model with which to test long-standing hypotheses about the role of gene duplication in evolutionary expansion, speciation and adaptation to the environment. This project will employ modern genomic techniques using genomic hybridization to identify duplicated genes. Gene duplicate number, gene duplication rate and retention of gene duplicates from specific functional categories will be investigated for an association with enhanced speciation as well as ecological diversification. Sequence analysis of duplicated genes across this group of fishes will address the degree to which natural selection is responsible for the evolution of gene duplicates.

In addition to the significant contribution to genomic resources for the cichlid research community, this project also advances a broad range of studies concerning the evolution of duplicated genes and their contribution to diversity and adaptation. The project, conducted at Reed College, will strengthen the genomics/bioinformatics program, capitalizing upon the PIs interdisciplinary collaborations. The cutting edge techniques and manipulation of large datasets will provide a rigorous training through the formation of an interdisciplinary research team involving undergraduate students of mathematics and biology. Furthermore, the research will be directly linked with the PIs teaching in Comparative Functional Genomics and will be incorporated into outreach teaching modules on animal diversity and genome evolution.

This project provides scholarships to able and financially needy students majoring in chemistry, physics, biology, mathematics, and interdisciplinary fields. The project emphasizes supporting students through formal and informal interactions with faculty and among students, seminars, and an opportunity for dedicated funds for their thesis research project, covering supplies and/or travel, when they become seniors.

Intellectual Merit: The academic programs into which the students go are strong, and there are academic support activities. The project targets attrition between the first and second year of college, and it provides incentives for students to declare and remain in a STEM major. The project builds on a successful scholarship project that is just being completed.

Broader Impact: The project is increasing the number and diversity of students who complete a STEM major and go on to work in the field or to further education.

President Obama's BRAIN Initiative (BRAIN; Brain Research through Advancing Innovative Neurotechnologies) is directed at supporting projects that seek to advance understanding of normal brain function. A workshop to identify areas where faculty and students from primarily undergraduate institutions (PUI) can make unique contributions to the BRAIN Initiative will be held on October 14-17, 2015 in Chicago, IL. The central goal of the workshop is to enhance PUI involvement in the research challenges described in the Brain Initiative. Consonant with advancing the goals of the BRAIN Initiative, the workshop will focus on developing ways to further NSF's mission to prepare a scientifically literate workforce.

A diverse group of twenty-four researchers from PUIs throughout the United States will be invited to participate in discussions of research, neurotechnology, computational approaches, and interdisciplinary training of undergraduates. The workshop will be held in Chicago, Illinois 3 days before the annual Society for Neuroscience (SFN) conference, also scheduled to be held in Chicago. Workshop participants will produce a report of their discussions, conclusions and recommendations aimed at increasing the participation of PUI faculty and their undergraduate research students in the BRAIN Initiative. The report will be made available to the public on the NSF website (http://www.nsf.gov/bio/pubs/reports/index.jsp ), and distributed to the scientific community through the Faculty for Undergraduate Neuroscience website (http://www.funfaculty.org/drupal/ ). The workshop outcomes will also be compiled into a self-running presentation for dissemination at local PUI consortia, academic conferences, and national meetings. It is anticipated that outcomes of the discussion at the workshop will be disseminated through conversations with researchers attending the SFN annual meeting.

Maternal care has evolved in many animals, yet most research on the underlying neural mechanisms has been carried out only in mammals. This project capitalizes on that rich body of research to study maternal mouth-brooding in the cichlid fish Astatotilapia burtoni. This species offers an independently-evolved instance of robust maternal care. Here, the neural circuits regulating maternal behavior must interact intimately with the neural circuits regulating feeding to allow voluntary starvation in order not to eat the young despite significant loss of body mass. The proposed experiments will be conducted at Reed College & Louisiana State University, providing research and exchange opportunities between undergraduates at a top liberal arts institution and both undergraduate and graduate students from an EPSCoR institution (LSU). Understanding the degree to which mechanisms and brain regions for feeding have been co-opted for maternal care will inform our general understanding of the evolution of this important adaptive social behavior. In addition to addressing the evolution of maternal care, this research may impact human health research related to metabolic and feeding disorders as it may uncover novel mechanisms that allow decoupling of these circuits.

This collaborative research project aims to understand the molecular and physiological mechanisms that underlie the behavioral switch from self-promoting behavior to offspring-promoting behavior that is required for robust maternal care. Astatotilapia burtoni has been a long standing model for sociogenomics and integrative animal behavior. Using immunohistochemistry, researchers and their students will quantify immediate-early gene expression in specific neuronal types across the "maternal brain" as well as assay cell types for changes in size or number. Using transriptomic approaches, they will quantify gene expression differences in candidate brain nuclei as well as peripheral signaling systems. Finally, in vivo neural recordings from neurons in the preoptic area will be used to determine physiological sensitivity to egg/fry versus food-related stimuli during different stages of maternal care. Fully describing the cichlid maternal brain as it interacts with feeding regulation is the long term collaborative agenda of the two researchers and allows them to capitalize on the synergy of simultaneously describing gene expression and functional studies. Students from Reed College and Louisiana State University will be involved in all aspects of this research. This project includes a math-biology collaboration to have students develop R scripts to interrogate similarity and differences between different gene expression networks in the different brain regions and different female groups. All resulting scripts and algorithms will be hosted online, disseminated through publication and presented by students at scientific conferences.

PROJECT SUMMARY Twentieth-century Danish physiologist August Krogh wrote that, ?for such a large number of problems there will be some animal of choice, or a few such animals, on which it can be most conveniently studied.? Formalized as ?Krogh's Principle? by biochemist Hans Krebs nearly 50 years later, this approach has become a guiding tenant for many scientific fields such as comparative physiology, neuroethology, and functional genomics. Investigations in such distantly-related model organisms provide great value to biomedical research specifically because they possess unique features that allow unprecedented insight to functions and dysfunctions that occur in humans. We invoke Krogh's principle to advance the mouth-brooding cichlid fish Astatotilapia burtoni as an innovative animal model for the study of metabolic regulation and dysregulation. In humans, the inappropriate decoupling of feeding behavior and metabolic rate is clearly maladaptive, severely compromising patient quality of life and even survival outcome without medical intervention. A. burtoni females undergo self induced starvation for as long as 30 days while brooding their young in their mouths - a prerequisite of reproduction - and yet recover to resume feeding and reenter the reproductive cycle after their young have achieved independence. In contrast to the human state, these fish provide an animal model in which the underlying mechanisms have been shaped by natural selection and can be conveniently studied. The synergistic aims of this proposal span physiological, gene regulatory networks, protein-expression, tissue histology, regulatory neural circuit analysis, and pharmacology to establish Astatotilapia burtoni as an animal model suited to the study of anorexia and, more broadly, appetite/metabolic regulation. Following metabolic measures and histology, neural and peripheral circuits are anatomically defined and functionally addressed through expression of activity markers, autoradiography, and pharmacology. Finally, we use a hypothesis-driven approach to test candidate neural and peripheral mechanisms with qPCR to complement a discovery-based Tag-Seq analysis of neural transcriptomes from identified brain nuclei in the feeding circuit, thereby identifying conserved and novel mechanisms of feeding regulation and lean tissue catabolism. Mechanisms of appetite regulation appear to be largely conserved between the teleost and mammalian lineages, allowing for many direct comparisons. However, sufficient phylogenetic distance and difference in selective pressures predict mechanistic adaptations in A. burtoni that are not present in mammals. These similarities and differences can inform both novel therapeutic approaches to devastating human disorders.