 |
|
Study looks at mitochondrial variation in sperm traits and sperm competitive ability
September 20, 2007Study considered an important link in the field of sexual selection, where maternal inheritance of mitochondria may well have its greatest impact on sperm traits and competitive ability but thus far has been largely overlooked
RENO, Nev. -- University of Nevada, Reno researchers Jeanne and David Zeh of the Department of Biology have received a five-year, $650,000 grant from the National Science Foundation to investigate the effects of natural mitochondrial variation on sperm traits and sperm competitive ability.
Researchers have found mitochondrial mutations to be one of the primary causes of low sperm count and poor sperm mobility in humans. However, in the field of sexual selection, where maternal inheritance of mitochondria may well have its greatest impact, female-limited response to selection has been largely overlooked. The Zehs' study promises to fill in some of this knowledge gap in evaluating the importance of maternal inheritance of mitochondria for sexual selection and male adaptation. Mitochondria are the principal energy source of a cell, and convert nutrients into energy as well as performing many other specialized tasks.
The Zehs' study, which will use a neotropical pseudooscorpion Cordylochernes scorpioides as a model system, will encompass whole-genome mitochondrial sequencing, a comprehensive analysis of the physiological and morphological characteristics of sperm that are likely to be important in competitive ability, a large-scale sperm competition experiment designed to identify the target of selection acting on sperm traits, and a replicated, multi-generation experiment in which the evolutionary response to selection on the trait most important in sperm competition will be assessed using both maternally- and paternally-based selection regimes.
Jeanne Zeh, an assistant professor of biology, and David Zeh, an associate professor of biology, both believe that their study will help refine the efforts to understand mitochondrial effects on male fertility.
"The fundamental insight that strict maternal inheritance of mitochondria constrains the ability of males to respond adaptively to selection has led to major advances in the study of human male infertility," said Jeanne Zeh, the principal investigator for the study, noting that other studies have also investigated this phenomenon in laboratory mice and domestic fowl. "However, these studies have not assessed the effects of natural mitochondrial DNA variation on male fertility and sperm competitive ability.
"Clearly, more research is needed, particularly on natural populations not subject to the potentially strong effects of genetic drift associated with domestication."
In addition to their research, the Zehs' study also includes an interesting outreach component. They plan on working with a local AP biology teacher who will serve as a graduate research assistant on the project, and they will hold a series of workshops and seminars for other local high school science teachers and students that will promote the importance for society of basic research in ecology and evolution.
University of Nevada, Reno
The Zehs' study, which will use a neotropical pseudooscorpion Cordylochernes scorpioides as a model system, will encompass whole-genome mitochondrial sequencing, a comprehensive analysis of the physiological and morphological characteristics of sperm that are likely to be important in competitive ability, a large-scale sperm competition experiment designed to identify the target of selection acting on sperm traits, and a replicated, multi-generation experiment in which the evolutionary response to selection on the trait most important in sperm competition will be assessed using both maternally- and paternally-based selection regimes.
Jeanne Zeh, an assistant professor of biology, and David Zeh, an associate professor of biology, both believe that their study will help refine the efforts to understand mitochondrial effects on male fertility.
"The fundamental insight that strict maternal inheritance of mitochondria constrains the ability of males to respond adaptively to selection has led to major advances in the study of human male infertility," said Jeanne Zeh, the principal investigator for the study, noting that other studies have also investigated this phenomenon in laboratory mice and domestic fowl. "However, these studies have not assessed the effects of natural mitochondrial DNA variation on male fertility and sperm competitive ability.
"Clearly, more research is needed, particularly on natural populations not subject to the potentially strong effects of genetic drift associated with domestication."
In addition to their research, the Zehs' study also includes an interesting outreach component. They plan on working with a local AP biology teacher who will serve as a graduate research assistant on the project, and they will hold a series of workshops and seminars for other local high school science teachers and students that will promote the importance for society of basic research in ecology and evolution.
University of Nevada, Reno
Mitochondrial Current Events and Mitochondrial News RSSDNA provides 'smoking gun' in the case of the missing songbirds
It sounds like a tale straight from "CSI": The bully invades a home and does away with the victim, then is ultimately found out with the help of DNA evidence.
Revealing the evolutionary history of threatened sea turtles
It's confirmed: Even though flatback turtles dine on fish, shrimp, and mollusks, they are closely related to primarily herbivorous green sea turtles.
Embryonic heart exhibits impressive regenerative capacity
A new study demonstrates that the embryonic mouse heart has an astounding capacity to regenerate, a phenomenon previously observed only in non-mammalian species.
A link between mitochondria and tumor formation in stem cells
Researchers report on a previously unknown relationship between stem cell potency and the metabolic rate of their mitochondria -a cell's energy makers. Stem cells with more active mitochondria also have a greater capacity to differentiate and are more likely to form tumors.
Making metabolism more inefficient can reduce obesity
In a discovery that counters prevailing thought, a study in mice has found that inactivating a pair of key genes involved in "fat-burning" can actually increase energy expenditure and help lower diet-induced obesity. These unusual findings, appearing this week in the JBC, might lead to some new roads in weight-loss therapy.
Researchers discover that growing up too fast may mean dying young in honey bees
Reactive oxygen species (ROS) occur as a by-product of aerobic metabolism and impair cellular function by damaging proteins, nucleotides and lipids.
Extinct may not be forever for some species of Galapagos tortoises
Yale scientists report that genetic traces of extinct species of Galapagos tortoises exist in descendants now living in the wild, a finding that could spur breeding programs to restore the species, The report appears in Proceedings of the National Academy of Sciences.
Cutting calories could limit muscle wasting in later years
Chemical concoctions can smooth over wrinkles and hide those pesky grays, but what about the signs of aging that aren't so easy to fix, such as losing muscle mass? Cutting calories early could help, say University of Florida researchers who studied the phenomenon in rats.
Trichoplax genome sequenced -- 'rosetta stone' for understanding evolution
Yale molecular and evolutionary biologists in collaboration with Department of Energy scientists produced the full genome sequence of Trichoplax, one of nature's most primitive multicellular organisms, providing a new insight into the evolution of all higher animals.
Study: DNA barcoding in danger of 'ringing up' wrong species
DNA barcoding is a movement to catalog all life on earth by a simple standardized genetic tag, similar to stores labeling products with unique barcodes. The effort promises foolproof food inspection, improved border security, and better defenses against disease-causing insects, among many other applications.
More Mitochondrial Current Events and Mitochondrial News Articles
 | Drug-Induced Mitochondrial Dysfunction This is the definitive, one-stop resource on preclinical drug evaluation for potential mitochondrial toxicity, addressing the issue upfront in the drug development process. It discusses mitochondrial impairment to organs, skeletal muscle, and nervous systems and details methodologies used to assess mitochondria function. It covers both in vitro and in vivo methods for analysis and includes the... |
 | Mitochondrial Pharmacology and Toxicology 2006 by Antonio J. M. Moreno This book examines recent developments in mitochondrial medicine, pharmacology and... |
 | Mitochondrial Medicine by Salvatore DiMauro, Michio Hirano, Eric A. Schon Mitochondrial dysfunction is increasingly being recognized as the basis of a wide variety of human diseases. Providing an authoritative update on our current knowledge of mitochondrial medicine, this text draws together world authorities from various fields to present general therapeutic strategies, as well as the treatments presently available in different specialties - thus making it essential... |
 | Human Mitochondrial DNA and the Evolution of Homo sapiens (Nucleic Acids and Molecular Biology) Mitochondrial DNA is one of the most explored genetic systems because of what it can tell us about the human past. This volume takes a unique perspective, presenting the disparate strands that must be tied together to exploit this system. From molecular biology to anthropology, statistics to ancient DNA, this first volume of three presents the global picture of human mitochondrial DNA variation.... |
 | Mitochondrial Medicine: Mitochondrial Metabolism, Diseases, Diagnosis and Therapy Mitochondrial Medicine is a relatively new area where several disciplines from basic science to clinical medicine converge. Mitochondrial medicine deals with diseases that are related to mitochondrial dysfunction due to a number of causes from free radical damage to genetic mutation. A primary feature of mitochondrial dysfunction is impaired cellular bioenergetics. This book is based upon... |
 | The Official Parent's Sourcebook on Mitochondrial Myopathies: A Revised and Updated Directory for the Internet Age by Icon Health Publications This book has been created for parents who have decided to make education and research an integral part of the treatment process. Although it also gives information useful to doctors, caregivers and other health professionals, it tells parents where and how to look for information covering virtually all topics related to mitochondrial myopathies (also Chronic Progressive External Ophthalmoplegia... |
 | Mitochondrial Function and Biogenesis (Topics in Current Genetics) Mitochondria are complex organelles, possessing a double-membrane and even their own genome, the mtDNA. They play a pivotal role in cellular metabolism, respiration, and production of ATP essential for the normal function of all human organ systems. It is not surprising, therefore, that genetic defects of mitochondrial functions cause a wide spectrum of human diseases. This book provides the... |
 | The Mitochondrial Free Radical Theory of Aging (Molecular Biology Intelligence Unit 9) (Molecular Biology Intelligence Unit) (Molecular Biology Intelligence Unit) by Aubrey D.N.J. de Grey Book Description AVAILABLE IN SOFT COVER AT $69, FEBRUARY, 2002, 1SBN # 1-58706-155-4. The vast complexity of organismal degeneration with age has too often intimidated gerontologists into over-cautious interpretation of their results. As a result, theories of mammalian aging have been too open and preliminary to underpin the design of medical interventions. This book breaks new ground in the... |
 | Genetics of Mitochondrial Diseases (Oxford Monographs on Medical Genetics, No. 47) Molecular genetics has revolutionised our understanding of human disease and nowhere is this more apparent than the group of diseases caused by mitochondrial dysfunction. The concept of mitochondrial diseases dates back only as far as the 1960s, and they were given little credence until mutations in mitochondrial DNA were found in the late 1980s. This international, edited book summarises the... |
 | Detection of Mitochondrial Diseases (Developments in Molecular and Cellular Biochemistry) In October 1995, the 1st Colloquium on Mitochondria and Myopathies in Halle/Saale was organized in Halle/Saale by the editors of this focused issue. The meeting took up what might be called an East German tradition: from 1976 to 1990 Andreas Schmidt organized seven clinically orientated Colloquia on Myology in Jena, and from 1974 to 1990 a series of twelve Colloquia on Mitochondria focused... |
| © 2008 BrightSurf.com |