Intragenome Diversity of Gene Families Encoding Toxin-like Proteins in Venomous Animals.

Abstract

The evolution of venoms is the story of how toxins arise and of the processes that generate and maintain their diversity. For animal venoms these processes include recruitment for expression in the venom gland, neofunctionalization, paralogous expansions, and functional divergence. The systematic study of these processes requires the reliable identification of the venom components involved in antagonistic interactions. High-throughput sequencing has the potential of uncovering the entire set of toxins in a given organism, yet the existence of non-venom toxin paralogs and the misleading effects of partial census of the molecular diversity of toxins make necessary to collect complementary evidence to distinguish true toxins from their non-venom paralogs. Here, we analyzed the whole genomes of two scorpions, one spider and one snake, aiming at the identification of the full repertoires of genes encoding toxin-like proteins. We classified the entire set of protein-coding genes into paralogous groups and monotypic genes, identified genes encoding toxin-like proteins based on known toxin families, and quantified their expression in both venom-glands and pooled tissues. Our results confirm that genes encoding toxin-like proteins are part of multigene families, and that these families arise by recruitment events from non-toxin genes followed by limited expansions of the toxin-like protein coding genes. We also show that failing to account for sequence similarity with non-toxin proteins has a considerable misleading effect that can be greatly reduced by comparative transcriptomics. Our study overall contributes to the understanding of the evolutionary dynamics of proteins involved in antagonistic interactions.

Issue Section: INTEGRATING PERSPECTIVES ON ANIMAL VENOM DIVERSITY\

Lead author Dr. Ricardo C. Rodríguez de la Vega tells us more about the research and goals behind this work:

What originally interested you in this area of research, be it venoms or intragenome diversity of toxin-like gene families? 

Both. My main scientific interest is how reciprocal selection in antagonistic biotic interactions is recorded at the genome level. The idea here is that recurrent interactions between species generate co-evolutionary dynamics such that, as one species evolves, selective pressures on the other change and vice-versa. This reciprocal selection would naturally ended up changing the genotypes of the interacting species, However, this co-adaptation signal can be difficult, even impossible, to read as multiple other selection pressures and random processes leading to fixation (drift) also shape the genomes. In my view, antagonistic interactions generate evolutionary battlefields with deployed “arms” that may be anything from behavioural to molecular traits. In a simple case where “effector” molecules produced by one organism are delivered into another organism targeting “receptor” molecules reducing its fitness, and insofar as these molecules have simple genetic bases, this can offer a direct link between identifiable genomic features and reciprocally selected multi-organism phenotypic outcomes.

I am convinced that animal venoms provide many parallel examples of such simple and tractable case. Yet, the systematic study of these processes requires, of course, the reliable identification of molecules mediating the antagonistic interaction. Enters thus the problem of identifying the “effectors” of these interactions. In the case of animal venoms, the effectors, aka toxins, are the venom components whose selected function has been shaped by the action they have on ecologically relevant foes. Ribosomally synthesized toxins conform multigene families in venomous animals, understanding how these families arise is of utmost importance to understand the evolution of venom function. Until very recently toxins were thought to mainly originate from recruitment events of proteins with intra-organismal selected function, be it after gene duplication followed by neo- or sub-functionalization, or by re-purposing the original gene once it is expressed in the venom producing organ.

Did you feel that there was something missing from the field that motivated this work?

Yes. The advent of high throughput sequencing and improvements in proteomic protocols have relieved the burden of painstaking characterization of individual toxins directly from the venoms. Indeed, it is possible to identify candidate toxins directly from the genes expressed in the venom producing organs or even in whole genome surveys, by comparing the translated sequences with those in toxin databases such as UniProt’s venom protein annotation program. However, the existence of genes homologous to bona fide toxins but with no selected function in the venom, poses the much real problem of distinguishing between toxin and toxin-like genes in simple similarity searches. Taking advantage of recently available whole genome sequences of several venomous animals, I asked two very simple questions: 1) can we distinguish genes encoding toxins from toxin-like proteins by similarity searches (i.e. annotation transfer)? and 2) what is the relative contribution of toxin and toxin-like encoding genes to their corresponding multi-gene families?

What new insights do we gain as a result of this work?

First, that properly done, similarity searches can distinguish between toxin and toxin-like encoding genes. Second, that for many toxin containing mutligene families, non-toxin homologs outnumber the bona fide toxins, Third, that merging toxin and non-toxin homologs mislead the interpretation of recruitment events and selection regimes.

What are the critical future direction(s) do you anticipate this field moving in?

Having demonstrated that toxins indeed belong to multigene families, but that most of their homologs are unlikely to have a selected function in the context of venom use is in line with more recent evidence of highly dynamic venom composition, not due to recent duplication and pervasive diversifying selection (the standard model of venom evolution), but rather to pervasive and differential gene losses and to the rapid turnover of genes to acquire venom gland expression (assuming these genes have/have had indeed a selected function in the context of venom use).

What did you personally find most interesting, fun, or rewarding about this research?

I found particularly rewarding to be part of what I consider an authentic coming to age volume on venom evolution.

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Article in focus: Thermal acclimation ability varies in temperate and tropical aquatic insects from different elevations

 Sorting insects

Summary:

Thermal acclimation is an animal’s ability to cope with changing temperature. Theory suggests that animals from high latitudes, where temperature varies widely, should have greater acclimation ability than those from tropical latitudes, where temperature is stable year-round. We tested this theory in aquatic insects from the Colorado Rockies (high latitude) and Ecuadorian Andes (low latitude). Our main finding was that Rocky mountain mayflies acclimated to warming temperatures much better than Andean mayflies. This suggests that Andean mayflies, and possibly other tropical mayflies, are more sensitive to warming and maybe more vulnerable to climate change than their Rocky Mountain counterparts.

 Lead author Alisha Shah (Colorado State University) tells us more about this project:

“I have been fascinated by questions related to species distributions. Why is it that some species are found worldwide but others have extremely restricted geographic ranges? Although there can be multiple explanations for this phenomenon, one important idea is that species differ in their thermal tolerances and ability to “acclimate” or adjust to different temperatures. I wanted to test this idea – that widely distributed animals have a better ability to acclimate, but narrowly distributed ones have a reduced ability to acclimate. Aquatic insects from different regions make a great group of animals to experiment with such questions. In fact, temperate aquatic insects tend to have larger home ranges than their tropical cousins. So, I was set to answer an interesting question about species distributions by using aquatic insects as test subjects.

 

(Left Colorado Stonefly: About 4 times the size of a mayfly, stoneflies are predatory insects and can be quite sensitive to pollutants. They are often used as bioindicators of stream health. Right Ecuadorian mayfly: The mayfly, little as it may be, is extremely important to the health of the river ecosystem. It consumes large quantities of algae and is itself a source of food for larger predators like stoneflies.)

“Aquatic insects are quite easy to collect from mountains streams. I collect insects from streams in the Rocky Mountains in Colorado and in the Andes mountains in Ecuador. For this project, I collected mayflies and stoneflies (both very important to stream ecosystems) from various elevations in the Rockies one year and the Andes the following year. For each group, I tested their ability to cope with rising experimental temperatures. First, I tested their normal response, i.e. what was the highest temperature they could handle? Then I put them in a hot water bath for 2 days and again tested their response. Could they now handle even higher temperatures? If they could, it suggested they had an ability to acclimate. If they couldn’t handle higher temperatures, it meant they did not have the ability to acclimate.

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Using a D-frame kicknet, Alisha scrapes and move aside large rocks to capture the insects residing on them (picture: Alisha Shah)

“We found that generally the tropical mayflies were really bad at acclimating. Many of them could not increase their tolerance to high temperatures. This is important because it means mayflies in the tropics may not be able to cope with climate warming as well as temperate ones. Stoneflies had a slightly different response, in that we did not see many differences between the Rocky Mountain and Andes individuals. This tells us that not all aquatic insects will respond the same way to rising temperature. Differences between them may arise because of their body shapes, feeding habits, behavior or maybe even their evolutionary history.

“Working with wild animals in natural systems (i.e. not in a lab) is always challenging. You never know what to expect! For example, in Ecuador, a massive landslide completely changed the course of a stream in which I would typically find a lot of insects. The damage was so great that when I eventually went back to look for insects, there were none there! On another occasion, while collecting insects from a small stream, we were suddenly shocked to find we were surrounded by a group of curious llamas. They must have waded in for a drink. Afraid that we’d be charged at or spat on, we gingerly stepped out of the stream and waited for them to move on.

“This research is only a first step toward understanding patterns of species distribution. It also gives us some idea of how some species will (or won’t) cope with climate change. Coupling this type of field research with a better understanding of the genetic bases of thermal tolerance is one important direction in which this research will move. Another vital piece of information is how entire communities of animals respond to changes in their environmental temperatures. These are all pieces of the puzzle that will ultimately give us the whole picture of how temperature shapes animal distributions and how these might change with global climate warming.

“Research in other countries is an incredible opportunity to delve into a different culture, to celebrate and appreciate our similarities and differences. Ecuador has become a home to me, and getting to know its stunning landscape and beautiful people has been a reward. I also find rivers and streams even more mysterious than before, and each research project seems to open up doors for new questions and insights into aquatic ecosystems. This, to me, is the most fun part of research – it doesn’t really ever end!”

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Alisha: “The Páramo region is found at the highest elevations in the Andes. It is often treeless and covered by high elevation grasses and yucca. We were incredibly lucky to see a female spectacled bear wandering around one of our field sites. Due to road construction, deforestation, and other forms of disruptive human activities, large apex predators like pumas and bears are slowly disappearing from the Ecuadorian highlands.” (picture: Alisha Shah)

Original article: https://doi.org/10.1093/icb/icx101

Alisha Shah ​is a Ph.D. candidate, advised by Dr. Cameron K. Ghalambor and Dr. W. Chris Funk, in the Biology department at Colorado State University.

http://alishashah.weebly.com/about.html

Twitter: @alishas2484

Article in Focus: Defining the Degree of Seasonality and its Significance for Future Research

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Summary:

A fundamental issue facing biologists interested in organisms’ adaptations to their environment is accurately evaluating seasonality. Seasonality involves a whole suite of cyclic factors organisms must deal with, and accurately modeling these seasonal dynamics remains a major challenge for researchers. With the major aim of advancing researchers ability to use a direct measure of seasonality, Lisovski et al. quantified seasonality based on the amplitude of the annual change and predictability of temperature, precipitation, and terrestrial primary productivity over years. Besides illustrating the variation of these measures across the globe, the authors are convinced that their results can be used to directly link seasonal dynamics of the environment with biological processes such as evolutionary adaptations and investigate why organisms respond to climate change in the way they do.

Lead author Dr. Simeon Lisovski told us more about his study:

“A major aim of this work was to illustrate the strength and predictability of seasonality across all terrestrial habitats to provide an overview that may stimulate ideas, concepts and hypotheses, as well as to provide results for further analysis to all researchers interested in seasonal dynamics.

“To me, working with data on a global scale is a major challenge. Certainly the handling of the massive amount of data, the development of code to process all data in the same way, and the processing power required for the analysis is one part of the challenge, but also the perspective one needs to develop to look at the data and draw the right conclusions. The analyses of large scale environmental patterns may allow investigations and links to equally large-scale biological processes such as differences in life-history strategies between temperate and arctic organisms, but may not be suitable for smaller scale analysis.

“With more and more environmental data available and better computational capacities we can start understanding global patterns such as seasonality much better and in more detail. We’ve learned that simplifications may be helpful for some questions, but are often too simple and rather biased (e.g. latitudinal trend in seasonality, which does exist, but depending on what variable you look at it deviates strongly across longitudes and most importantly between the southern and northern hemisphere). I hope that the on-going development will soon allow us to work on large- as well as small scales and that we can then better understand how these scales differ in the influence on biological (e.g. evolutionary) processes.

“I just love to use these large datasets and analyze them in novel (and already established) ways that identify hypothesized patterns or identify new patterns that quite often puzzle me and which I then try to understand (not often successfully).”

Original article: https://doi.org/10.1093/icb/icx040

Simeon Lisovski is a post-doctoral researcher at the Swiss Ornithological Institute. He is mainly interested in bird migration and how the environment and changes therein, such as habitat destruction and shift in phenology, as well as biological interactions, such as host-pathogen interactions, affects migration strategies of individuals, populations and entire flyways. Since this work required formal description and quantifications of seasonal dynamics, he became also interested in this analysis of global remote sensing datasets. Simeon finished his PhD on host-pathogen interactions and seasonal influences on birds at Deakin University in Australia in 2016. Afterwards, he joined the lab of John Wingfield and Marilyn Ramenofsky at the University of California in Davis before he moved to Switzerland in 2017 (email contact: Simeon.Lisovski@gmail.com).

Maternal Programming of Body Weight in Syrian Hamsters

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Food hoarding and intake are monitored using individual ‘borrows’ consisting of a home cage with tunnels running up a food source in 90 min tests. (Copyright © Jeremy M. Brozek)

Synopsis

Maternal programming of offspring energy balance has been viewed as an adaptation in which the gestational environment prepares the offspring to thrive and reproduce in that same postnatal environment. Programming might have the opposite effect, however, when gestational and postnatal environments are mismatched. Gestational programming would represent a trade-off if the mother can maximize fitness in one possible energetic future but cannot maximize fitness in another. The vast majority of research concerns rats, mice, or sheep, and dams are typically food restricted by 30–70% of ad libitum intake resulting in low birth weight and adult obesity in offspring. Few previous studies have used a lower level of food restriction, and no experiments, to the best of our knowledge, were designed to determine whether the effects of gestational restriction have postgestational effects independent of the effects that occurred during gestation. In the present experiment, Syrian hamsters were either restricted to 90% of their ad libitum food intake or fed ad libitum during pregnancy. All litters were cross-fostered at birth and all were fed ad libitumduring lactation. Half of the litters from ad libitum-fed pregnant dams were fostered to dams that had been food restricted during pregnancy and half of the litters from food-restricted pregnant dams were fostered to ad libitum-fed dams. The latter group allowed us to test the hypothesis that the effects of having a gestationally food-restricted mother affects offspring characteristics independent of the prenatal programming. First, we found significant increases in the postnatal body weight of the offspring of ad libitum-fed mothers fostered to food-restricted dams, supporting the hypothesis that the effects of gestational restriction carry over to postnatal maternal ability (e.g., milk yield, milk content, or parental behavior). Second, the carry-over effects of gestational food restriction on offspring postnatal body weight were significant in male but not female offspring. This occurred even though this group had significantly lower food intake than offspring of ad libitum-fed mothers with ad libitum-fed foster mothers. In addition, and contrary to expectation, gestational food restriction had no significant effect on adult baseline food hoarding or food hoarding in response to food restriction. These results suggest that even mild energetic challenges during gestation can have postgestational effects on maternal ability, and the effects on offspring are sex-specific.

 Issue Section:  Evolutionary Tradeoffs: Molecular and Neuroendocrine Approaches

Lead author Dr. Jeremy Brozek tells us more about the research and goals behind this work:

“Syrian hamsters present several unique challenges to research on maternal programming. They are native only to a small area of northern Syria and southern Turkey, and very little is known about their biology in the wild. Also, a normal behavior for Syrian hamsters is predation of offspring within the first five days after birth. This well documented behavior influences the sample sizes associated with laboratory studies using hamster offspring.”

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Syrian hamsters have cheek pouches that extend almost to their hips, aiding in their prodigious hoarding behavior. (Copyright © Jeremy M. Brozek)

“We found that food restricting a mom during gestation must influence the mother’s ability to care for their offspring while the offspring grow and develop after birth because of carry-over effects. These carry-over effects will influence an individual’s ability to survive and reproduce in the wild. This pattern would not have been observed without swapping offspring between mothers that were treated differently during gestation. Therefore, conclusions about the influence of gestational food intake on offspring development may not be clear without using parental fostering in experimental designs.”

 

“One of the most interesting aspects of this research was that my hypothesis about hoarding behavior was not supported. I thought that any influence on body weight in Syrian hamsters should have been through food motivation because motivation is more sensitive than food intake in response to changes in food/energy availability. This was the first study on Syrian hamsters that I know of which attempted to connect maternal energy balance during gestation with adult offspring motivation for food. So, I think that more studies are warranted before shelving my hypothesis.”

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Here is food hoard that a hamster gathered in 90 minutes. All behavior is monitored under red lights. (Copyright © Jeremy M. Brozek)

“Future studies on Syrian hamsters need to uncover the mechanisms that links maternal energy balance to changes in offspring growth and weight gain. In a broader context, much of the literature on maternal programming is focused on health and disease in translational research. I think that the direction of future studies should be to confirm that the underlying mechanisms associated with programming occur in wild populations and look for influences on survival and reproduction. Can these developmental changes influence allele frequencies over time, and thus play a role in the evolution of populations?”

To learn more about Dr. Jeremy Brozek’s work, check out his Researchgate profile. This work was completed in the lab of Dr. Jill Schneider.

 

Integrating Ecological and Evolutionary Context in the Study of Maternal Stress

Michael J. Sheriff, Ph.D.

George A. Bartholomew Award Winner:

Michael Sheriff (Penn State University)

Each year the Division of Comparative Physiology and Biochemistry recognizes a young investigator for distinguished contributions to comparative physiology and biochemistry or to related fields of functional and integrative biology. The George A. Bartholomew Award offers the awardee a fantastic opportunity to communicate this research via a large lecture at this year’s SICB conference. In 2017 Dr. Sheriff was received this award, resulting in  a synopsis for the Special Issue: Bartholomew Award Lecture. Here we interview Dr. Sheriff about his recently published work.

To learn more about the George A. Bartholomew Award click here.

Abstract

Maternal stress can prenatally influence offspring phenotypes and there are an increasing number of ecological studies that are bringing to bear biomedical findings to natural systems. This is resulting in a shift from the perspective that maternal stress is unanimously costly, to one in which maternal stress may be beneficial to offspring. However, this adaptive perspective is in its infancy with much progress to still be made in understanding the role of maternal stress in natural systems. Our aim is to emphasize the importance of the ecological and evolutionary context within which adaptive hypotheses of maternal stress can be evaluated. We present five primary research areas where we think future research can make substantial progress: (1) understanding maternal and offspring control mechanisms that modulate exposure between maternal stress and subsequent offspring phenotype response; (2) understanding the dynamic nature of the interaction between mothers and their environment; (3) integrating offspring phenotypic responses and measuring both maternal and offspring fitness outcomes under real-life (either free-living or semi-natural) conditions; (4) empirically testing these fitness outcomes across relevant spatial and temporal environmental contexts (both pre- and post-natal environments); (5) examining the role of maternal stress effects in human-altered environments—i.e., do they limit or enhance fitness. To make progress, it is critical to understand the role of maternal stress in an ecological context and to do that, we must integrate across physiology, behavior, genetics, and evolution.

What originally interested you in this area of research? 

“Research into the impacts of maternal stress on offspring originated and is still led by the biomedical community, who’s outlook is that maternal stress is bad for babies. It is with this assumption that I began my work in maternal stress, and what the consequences of predator-induced maternal stress may be on the population cycle of snowshoe hares. However, being part of an exceptionally strong ecology and evolutionary department at the University of British Columbia I really started to question what would be the adaptive significance of maternal stress. If it was truly negative, then it should be selected against, yet we see the effects of maternal stress on offspring across many diverse taxa. Thus, I really became interested in understanding the adaptive role maternal stress plays in ecological and evolutionary processes.”

Did you feel that there was something missing from the field that motivated this work?

“It was the lack of recognition that maternal stress could play an adaptive role in ecological processes that originally interested me in this work. I feel that we are now at a point that we can push the field of maternal stress effects even further and this paper is really about doing just that – about providing novel insights and direction for future studies.”

What new insights do we gain as a result of this work?

“Broadly this paper provides insights into novel aspects of research where we think the field needs to progress: 1) understanding the mechanisms that control offspring exposure to maternal stress; 2) understanding the dynamic nature of the interactions between mothers and their environment, which ultimately drives the level of stress experienced by mothers; 3) actually comparing fitness outcomes of both mothers and offspring (control and stress- exposed) across relevant, real-life environmental contexts; 4) examining the role of maternal stress effects in human-alter environments.”

What did you personally find most interesting, fun, or rewarding about this paper?

“This paper was a large collaborative effort with many brilliant scientists. I asked each of them to come up with a few areas of research where they felt the field needed to progress, which we then discussed, digested, and broke down or combined into broad categories. I found the entire process extremely rewarding, particularly the ability to brainstorm and have insight into how each of us thinks about this field.”

What sort of advice to you have for future George A. Bartholomew Award winners?

“Enjoy the moment and write the follow-up paper! I found this award along with the invited paper provided a fantastic opportunity to gather an amazing group of people together to work on something I find very interesting.”

Article in focus: Group Living and Male Dispersal Predict the Core Gut Microbiome in Wild Baboons

Summary:
Although variation in the mammalian gut microbiome is likely to be important for host health, biologists don’t know much about what causes variation between individuals, especially the role of host social environment (who they hang out with in their immediate group, and contact with other groups, for example). This study used microbiome samples from 78 wild yellow baboons (Papio cynocephalus) living in two social groups to test how host social context, including group living, social interactions within groups, and transfer between social groups (e.g., dispersal) predict inter-individual variation in gut microbial alpha and beta diversity. The authors also tested whether social effects differed for the main gut microbes which are likely to play more important roles, relative to rarer microbes. They found that microbial communities differed between social groups both in terms of “core” microbes, and rarer microbes. Within social groups, close grooming partners had more similar core microbiomes, but not non-core microbiomes, than individuals who rarely groomed each other, even controlling for kinship and diet similarity between grooming partners. This study suggests that social context is important in determining variation in individual gut microbiome! 
Lead author Dr. Laura Greineisen tells us more about the research and goals behind this work:

“Research in the Archie Lab focuses on the evolution of social behavior in wild mammals. Past studies in the lab have looked at the role of social behavior in transmission of gastrointestinal parasites. We wanted to test if similar forces were at work in the transmission of commensal or potentially beneficial gut microbiota.

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Photo: Catherine Markham

“This study is the first to show that the length of time an immigrant animal has been a member of his current social group predicts how similar his gut microbes are to other group members. It suggests that as animals move, they may acquire local gut microbes. We know that there are health costs when animals or humans travel to new places; humans get traveler’s diarrhea, for example. Our work suggests that picking up the local gut microbes could help immigrating non-human animals (or traveling humans) adapt to local foods, diseases, and environmental conditions more quickly.

“One challenge I ran into was data processing. This study was the first time I had analyzed high throughput sequencing data on the thousands of taxa in the microbiome—it’s a ton of data. I had to learn how to run code in the command line and how to conduct statistical analyses in R. Fortunately, Josh Livermore (second author) was a patient teacher. A cool aspect of studying microbiomes is the broad array of skills required to collect and interpret the data; scientists with backgrounds in animal behavior and ecology must also learn techniques from computational biology.

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Photo: Susan Alberts

“Host-associated microbial communities are studied in a wide range of social animals. An important question to answer next is if microbes that are socially transmitted affect an animal’s health and well-being; i.e., does it matter if you share more bacteria with your friends? I think a broader critical question in this field is, how do animals acquire their gut microbes? We know that diet, host genetics, and illness affect the number and types of microbes in an animal’s gut. However, recent work has shown that animals living in different environments have different gut bacteria, suggesting that the environment is an unappreciated, but important, sculptor of the gut microbiome.

“A particularly rewarding aspect of this research is that I collected the fecal samples for this project during my first summer of grad school and the paper was published in Integrative & Comparative Biology the same week that I defended my dissertation. So, I think of this research as the bookends of my PhD!”

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Waiting for a fecal sample (Photo credit: Liz Miller).

 

Article details:

Integrative and Comparative Biology, Volume 57, Issue 4, 1 October 2017, Pages 770–785, https://doi.org/10.1093/icb/icx046
Published: 29 September 2017

With a little help from my friends: microbial partners in integrative and comparative biology

Our current (October) issue features eleven articles as part of a symposium focusing on the role that host-associated microbes play in animal biology, entitled “With a little help from my friends: microbial partners in integrative and comparative biology”.

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Symposium co-organiser (and author of the article “An Introductory “How-to” Guide for Incorporating Microbiome Research into Integrative and Comparative Biology”, pp 674-681) Dr. Kevin Kohl (University of Pittsburgh) explains the motivations behind the symposium, where he sees the field of microbiome research going, and what he enjoyed most about putting this issue section together:

“In 2012, Dr. Margaret McFall-Ngai gave the plenary symposium at a SICB meeting (which can be seen below). In her talk she highlighted the fact that animals live in a microbial world, and so we must consider these interactions when thinking about animal biology. However, these interactions hadn’t been recognized by the society as a whole. It is my hope that this symposium and the resulting papers help to call attention to the great work that’s being done on host-microbe interactions in integrative and comparative biology, and I hope it causes more researchers to consider aspects of microbial communities in their study systems.

“I think that the numerous talks at the symposium (and articles in this issue) really highlighted that host-microbe interactions can strongly impact many aspects of host biology. We saw that microbes play many roles such as detoxification of diets, helping animals utilize novel energy sources, training animals’ immune systems to help them fend off later pathogens, etc. These findings really support the idea that microbial associations could strongly impact the evolution of their animal hosts.

“The field of host-microbe interactions in integrative and comparative biology could still gain from more research on the functions and impacts of these microbial communities for their hosts, though there is already a bit of exciting work being done. Another area of future research could be to start uncovering the mechanisms of the shifts we see in microbial community structure, as well as the mechanistic underpinnings of how microbes impact the physiology of their hosts. It will be interesting to see whether these mechanisms are similar or different across different animal groups.

“I really enjoyed seeing the directions that people are taking host-microbe research, such as interactions with aspects of nutrition, disease ecology, behavior, etc. Something I was very pleased to see was how many researchers are using creative ways to study the actual function of microbial communities and their impacts on hosts. We also had a lunchtime workshop where we offered an ‘introduction in incorporating the microbiome into integrative and comparative biology’. We had over 45 participants, and I hope to see more researchers incorporating the microbiome into their systems!”