Science Current Events | Science News | Brightsurf.com
 

Monogamy and the Immune System

August 31, 2012
In the foothills of the Santa Cruz Mountains two closely related species of mice share a habitat and a genetic lineage, but have very different social lives. The California mouse (Peromyscus californicus) is characterized by a lifetime of monogamy; the deer mouse (Peromyscus maniculatus) is sexually promiscuous.

Researchers at the University of California Berkeley recently showed how these differences in sexual behavior impact the bacteria hosted by each species as well as the diversity of the genes that control immunity. The results were published in the May 2012 edition of PLoS One.

Monogamy is a fairly rare trait in mammals, possessed by only five percent of species. Rarely do two related, but socially distinguishable, species live side-by-side. This makes these two species of mice interesting subjects for Matthew MacManes, a National Institutes of Health-sponsored post-doctoral fellow at UC Berkeley.

Through a series of analyses, MacManes and researchers from the Lacey Lab examined the differences between these two species on the microscopic and molecular levels. They discovered that the lifestyles of the two mice had a direct impact on the bacterial communities that reside within the female reproductive tract. Furthermore, these differences correlate with enhanced diversifying selection on genes related to immunity against bacterial diseases.

Bacteria live on every part of our bodies and have distinctive ecologies. The first step of MacManes project involved testing the bacterial communities that resided in the vaginas of both species of mice - the most relevant area for a study about monogamous and promiscuous mating systems.

Next, MacManes performed a genetic analysis on the variety of DNA present, revealing hundreds of different types of bacteria present in each species. He found that the promiscuous deer mouse had twice the bacterial diversity as the monogamous California mouse. Since many bacteria cause sexually transmitted infections (like chlamydia or gonorrhea), he used the diversity of bacteria as a proxy for risk of disease. Results of the study were published in Naturwissenschaften in October 2011.

But this wasn't the end of the exploration.

"The obvious next question was, does the bacterial diversity in the promiscuous mice translate into something about the immune system, or how the immune system functions?" MacManes asked.

MacManes hypothesized that selective pressures caused by generation after generation of bacterial warfare had fortified the genomes of the promiscuous deer mouse against the array of bacteria it hosts.

To find out, he sequenced genes related to immune function of the two mice species and compared each species' versions of one important immunity gene, MHC-DQa. Some forms of genes (alleles) are better at recognizing different pathogens than others. If an individual has only a single common allele, it may only recognize a limited set of bacterial pathogens. In contrast, if an individual has two different alleles it may recognize a more diverse set of bacterial pathogens, and thus be more protected against infection.

Based on a comparison of the two species' genotypes he confirmed that the promiscuous mice had much more diversity in the genes related to their immune system.

"The promiscuous mice, by virtue of their sexual system, are in contact with more individuals and are exposed to a lot more bacteria," MacManes said. "They need a more robust immune system to fend off all of the bugs that they're exposed to."

The results, published in PLoS One, match findings in humans and other species with differential mating habits. They show that differences in social behavior can lead to changes in the selection pressures and gene-level evolutionary changes in a species.

Motivated by this result, MacManes began work on a project that looked to understand the genetics of a far more complex behavior-whether to stay at home with relatives, or to disperse to a new burrow.

Scientists have been sequencing and exploring the genome for more than a decade. For much of this time, studies have been limited to the most common and well-known species: humans, lab-mice, and fruit flies. But in recent years, as the cost of sequencing has dropped and the methods of exploring genomic information have improved, researchers have begun to analyze other less traditional organisms.

MacManes project was one of the first studies to use next-generation gene sequencing and high performance computers to assess the influence of behavior on genes in a non-model species.

"This is a field that people have always been interested in, but the tools hadn't existed yet for people to really understand how complex the mechanisms were," MacManes said.

Next-generation sequencing determines the order of the nucleotide bases in a molecule of DNA by breaking the double helix into short fragments and rapidly analyzing thousands of chunks at a time. Once hundreds of millions of genetic snippets have been read out by a DNA sequencer, they must be assembled into a single genome, or mapped to a reference genome, and compared to other genetic sequences to be useful.

"The sequencing is something that you can do in any molecular biology lab-that's easy," MacManes said. "But when you try to do an analysis of the data, you get back something like several billion base pairs of data. How to actually analyze the data is the real issue."

As a National Science Foundation (NSF) graduate research fellow, MacManes learned that researchers could access NSF supercomputers through the Extreme Science and Engineering Discovery Environment (XSEDE) to analyze datasets too big for their university laboratory clusters. Once he had his sequences, MacManes turned to the Texas Advanced Computing Center (TACC) at The University of Texas at Austin, a lead partner in XSEDE and home to the Ranger supercomputer.

"When we first started using Ranger, it was a breakthrough moment for us," he said. "We had the data set, but we didn't have any way to do anything with it. Ranger was really our first real chance at analyzing this data. "

The alignment and analysis that MacManes accomplished on Ranger in a few weeks would have taken years with his local resources. It organized the data so MacManes could find insights about the relationship between genes and behavior.

"The ability to isolate and compare genetic differences related to social behavior using advanced computing is a fascinating application of emerging technologies," said Jennifer Verodolin, a researcher specializing in social rodents at the National Evolutionary Synthesis Center in Durham, North Carolina. "We often see individual and population-level social and mating differences within the same species. While ecological factors are linked to this variation, these sophisticated new tools will now allow us to see the genetic signature of how natural selection has shaped behavior."

Mating systems, and social systems more broadly, are important to basic evolutionary biology, MacManes asserted. "The things an animal does, the way it behaves, and who it interacts with, are important to natural selection. These factors can cause immunogenes to evolve at a much faster rate, or slower in the case of monogamous mice. That connection is important and probably under-recognized."

Monogamy and promiscuity are only one of a variety of social behaviors that are thought to influence gene expression. MacManes' current research involves analyzing gene expression in the hippocampus brain region of tuco tucos (a sort of South American gopher) who live together in social groups and others who live independently. He is hoping to find what differentiates the social animals from the loners and what impact this change in their behavior has on their genetic profile.

"Now that we have these new sequencing technologies, people are going to be really interested in looking at the mechanisms that underlie these behaviors," MacManes said. "How might genes control what we do, and how we behave? We're going to see an explosion in these studies where people start to understand the very basic genetic mechanism for all sorts of behaviors that we know are out there."

Texas Advanced Computing Center


Related Immune System Current Events and Immune System News Articles


Mammary gland is shaped by adaptive immune system during development
In experiments with mouse tissue, UC San Francisco researchers have discovered that the adaptive immune system, generally associated with fighting bacterial and viral infections, plays an active role in guiding the normal development of mammary glands, the only organs--in female humans as well as mice--that develop predominately after birth, beginning at puberty.

HIV particles do not cause AIDS, our own immune cells do
Researchers from the Gladstone Institutes have revealed that HIV does not cause AIDS by the virus's direct effect on the host's immune cells, but rather through the cells' lethal influence on one another.

Blood vessel cells help tumours evade the immune system
A study by researchers at Sweden's Karolinska Institutet is the first to suggest that cells in the tumour blood vessels contribute to a local environment that protects the cancer cells from tumour-killing immune cells.

Compound found in red wine causes conflicting changes in dogs' immune systems
Resveratrol, a compound found commonly in grape skins and red wine, has been shown to have several potentially beneficial effects on health, including cardiovascular health, stroke prevention and cancer treatments.

Researchers identify signature of microbiomes associated with schizophrenia
In the most comprehensive study to date, researchers at the George Washington University have identified a potential link between microbes (viruses, bacteria and fungi) in the throat and schizophrenia.

Study provides hope for some human stem cell therapies
An international team of scientists headed by biologists at UC San Diego has discovered that an important class of stem cells known as human "induced pluripotent stem cells," or iPSCs, which are derived from an individual's own cells, can be differentiated into various types of functional cells with different fates of immune rejection.

Breastfeeding may expose infants to toxic chemicals
A widely used class of industrial chemicals linked with cancer and interference with immune function--perfluorinated alkylate substances, or PFASs--appears to build up in infants by 20%-30% for each month they're breastfed, according to a new study co-authored by experts from Harvard T.H. Chan School of Public Health.

Harvard's Wyss Institute improves its sepsis therapeutic device
Last year, a Wyss Institute team of scientists described the development of a new device to treat sepsis that works by mimicking our spleen. It cleanses pathogens and toxins from blood circulating through a dialysis-like circuit.

A paradigm shift in multidrug resistance
Bacteria are pretty wily creatures. Take for example, an organism such as Salmonella, which which are killed by antibiotics in lab tests, but can become highly resistant in the body.

In uveitis, bacteria in gut may instruct immune cells to attack the eye
The inflammatory eye disorder autoimmune uveitis occurs when a person's immune system goes awry, attacking proteins in the eye.
More Immune System Current Events and Immune System News Articles

The Immune System, 4th Edition

The Immune System, 4th Edition
by Peter Parham (Author)


The Immune System, Fourth Edition emphasizes the human immune system and presents immunological concepts in a coherent, concise, and contemporary account of how the immune system works. Written for undergraduate, medical, veterinary, dental, and pharmacy students, it makes generous use of medical examples to illustrate points. This classroom-proven textbook offers clear writing, full-color illustrations, and section and chapter summaries that make the book accessible and easily understandable to students. The Fourth Edition is a major revision that brings the content up-to-date and improves clarity. Based on user feedback, there is now increased continuity and connectivity between chapters.

The Immune System Recovery Plan: A Doctor's 4-Step Program to Treat Autoimmune Disease

The Immune System Recovery Plan: A Doctor's 4-Step Program to Treat Autoimmune Disease
by Susan Blum (Author), Mark Hyman (Foreword), Michele Bender (Foreword)


One of the most sought-after experts in the field of functional medicine shares her proven four-step program to treat, reverse, and prevent autoimmune conditions and repair your immune system.

• Are you constantly exhausted?

• Do you frequently feel sick?

• Are you hot when others are cold, or cold when everyone else is warm?

• Do you have trouble thinking clearly, aka “brain fog”?

• Do you often feel irritable?

• Are you experiencing hair loss, dry skin, or unexplained weight fluctuation?

• Do your joints ache or swell but you don’t know why?

• Do you have an overall sense of not feeling your best, but it has been going on so long it’s actually normal to you?

IF you answered yes to any...

The Immune System, 3rd Edition

The Immune System, 3rd Edition
by Peter Parham (Author)


The Immune System, Third Edition emphasizes the human immune system and synthesizes immunological concepts into a comprehensible, up-to-date, and reader-friendly account of how the immune system works.  Written for undergraduate, medical, veterinary, dental, and pharmacy students in immunology courses, it makes generous use of medical examples to illustrate points.  The Third Edition has been extensively revised and updated and includes two new chapters on innate and adaptive immunity, which explore the physical, cellular, and molecular principles underlying these responses to infection.  It also features enhanced coverage of aspects of innate immunity such as the complement system, Toll-like receptors, defensins, and C-reactive protein; the role of dendritic cells in initiating...

How the Immune System Works, Includes Desktop Edition

How the Immune System Works, Includes Desktop Edition
by Lauren M. Sompayrac (Author)


How the Immune System Works is not a comprehensive textbook. It's the book thousands of students have used to help them understand what's in their big, thick, immunology texts. In this book, Dr. Sompayrac cuts through the jargon and details to reveal, in simple language, the essence of this complex subject. Fifteen easy to follow lectures, featuring the uniquely popular humorous style and engaging analogies developed by Dr Sompayrac, provide an introduction to the 'bigger picture', followed by practical discussion on how each of the components interacts with one another. Now featuring full-color diagrams, this book has been rigorously updated for its fourth edition to reflect today's immunology teaching and includes updated discussion of B and T cell memory, T cell activation, vaccines,...

Immune System: The Ultimate Immune System Guide - How To Build An Unbreakable Natural Immune System (Autoimmune, Pain Management, Diet Therapy, Anti Inflammatory, ... Clean Eating, Healthy Habits, Healing)

Immune System: The Ultimate Immune System Guide - How To Build An Unbreakable Natural Immune System (Autoimmune, Pain Management, Diet Therapy, Anti Inflammatory, ... Clean Eating, Healthy Habits, Healing)


Boost Your Immune System Immediately!
Are You Often Getting Sick?

Millions of people are always ill through bad habits and poor choices. Many people realize how they should feel and act, yet are unable to break away from their ingrained routine. They often feel as if they are in a constant battle with sickness, not only does this affect their body in it's ability to function to it's best capacity but often spills over into others areas of their lives. Your immune system is your greatest line of defense against disease, without a strong immune system you are opening yourself up to an entire list of debilitating illness.

Create An Unstoppable Immune System!

If you are suffering from constant battles with disease and infection, it's that you don't...

The Immune System

The Immune System
by Peter Parham (Author)


The Immune System, Second Edition has been designed for use in immunology courses for undergraduate, medical, dental, and pharmacy students. This class-tested and successful textbook synthesizes the established facts of immunology into a comprehensible, coherent, and up-to-date account of how the immune system works, rather than presenting immunology as a chronology of experiments and discoveries. Emphasizing the human immune system the text has been designed to break down the barriers which often divide basic and clinical immunology. The reader-friendly text, section and chapter summaries, and full-color illustrations make the book accessible and easily understandable to students. The Immune System is adapted from Immunobiology by Janeway, Travers & Walport.

Super Immunity: The Essential Nutrition Guide for Boosting Your Body's Defenses to Live Longer, Stronger, and Disease Free

Super Immunity: The Essential Nutrition Guide for Boosting Your Body's Defenses to Live Longer, Stronger, and Disease Free
by Joel Fuhrman (Author)


In Super Immunity, world-renowned health expert and New York Times bestselling author of Eat to Live Dr. Joel Fuhrman offers a nutritional guide to help you live longer, stronger, and disease free.Dr. Fuhrman doesn’t believe the secret to staying healthy lies in medical care—rather, the solution is to change the way we eat. With more than 85 plant-based recipes, a two-week menu plan, and lists of super foods that boost immunity, Dr. Fuhrman’s proven strategies combine the latest data from clinical tests, nutritional research, and results from thousands of patients .Fans of Alejandro Junger’s Clean, Mark Hyman’s Ultraprevention, and T. Colin Campbell’s The China Study will appreciate Dr. Fuhrman’s practical plan to prevent and reverse disease—no shots, drugs or sick days...

The Autoimmune Solution: Prevent and Reverse the Full Spectrum of Inflammatory Symptoms and Diseases

The Autoimmune Solution: Prevent and Reverse the Full Spectrum of Inflammatory Symptoms and Diseases
by Amy Myers (Author)


Over 90 percent of the population suffers from inflammation or an autoimmune disorder. Until now, conventional medicine has said there is no cure. Minor irritations like rashes and runny noses are ignored, while chronic and debilitating diseases like Crohn's and rheumatoid arthritis are handled with a cocktail of toxic treatments that fail to address their root cause. But it doesn't have to be this way.In The Autoimmune Solution, Dr. Amy Myers, a renowned leader in functional medicine, offers her medically proven approach to prevent a wide range of inflammatory-related symptoms and diseases, including allergies, obesity, asthma, cardiovascular disease, fibromyalgia, lupus, IBS, chronic headaches, and Hashimoto's thyroiditis.

Basic Immunology: Functions and Disorders of the Immune System, 4e

Basic Immunology: Functions and Disorders of the Immune System, 4e
by Abul K. Abbas MBBS (Author), Andrew H. H. Lichtman MD PhD (Author), Shiv Pillai MBBS PhD (Author)


Understand all the essential concepts in immunology with Basic Immunology: Functions and Disorders of the Immune System! This concise, focused text provides you with an up-to-date, accessible introduction to the workings of the human immune system. Efficiently master the immunology information you need through clinically focused content, logically organized by mechanism. Apply what you've learned to real-world situations by referencing the appendix of clinical cases. Enhance your learning with the help of numerous full-color illustrations and useful tables, as well as summary boxes, review questions, and a glossary of immunology terms.Study immunology anywhere! Online access to www.StudentConsult.com opens the door to an enhanced e-book and ancillary components!Visualize complex...

The Immune System Cure: Optimize Your Immune System in 30 Days-The Natural Way!

The Immune System Cure: Optimize Your Immune System in 30 Days-The Natural Way!
by Lorna Vanderheaghe (Author)


What causes one person to catch a cold or flu and another to avoid it? Why do serious outbreaks of infectious diseases leave some individuals untouched? What allows someone to be incapacitated by allergies? The answer lies within nature itself-our immune system. The Immune System Cure provides simple techniques for supercharging your immune system to resist and prevent disease. Through diet, exercise, stress reduction and nutritional supplements, including plant sterols and sterolins, you can harness the power of your immune system in just 30 days and help it combat: Antibiotic-resistant bacteria Fibromyalgia Allergies Hepatitis C Tuberculosis Cancer Rheumatoid arthritis and other autoimmune diseases Chronic fatigue syndrome and more Now you can maintain a healthy natural resistance to...

© 2015 BrightSurf.com