ScienceDaily
Your source for the latest research news
Follow Facebook Twitter LinkedIn Subscribe RSS Feeds Newsletters
New:
  • Unprecedented Glimpse of Merging Galaxies
  • Chimps Synchronize Their Steps Just Like Humans
  • Secrets of Namibia's Fairy Circles Demystified
  • Black Death Shaped Evolution of Immunity Genes
  • Methane-Eating 'Borgs' Taking Earth's Microbes
  • Pain Relief Without Side Effects and Addiction
  • Accounting For Dark Energy and Dark Matter
  • Meet the First Neanderthal Family
  • Physicists Confirm Hitch in Proton Structure
  • Five Hours' Sleep a Night: Disease Risk
advertisement
Follow all of ScienceDaily's latest research news and top science headlines!
Science News
from research organizations

1

2

Researchers Discover That Sheep Need Retroviruses For Reproduction

Date:
September 11, 2006
Source:
Texas A&M University - Agricultural Communications
Summary:
A team of scientists from Texas A&M University and the University of Glasgow Veterinary School in Scotland has discovered that naturally occurring endogenous retroviruses are required for pregnancy in sheep. In particular, a class of endogenous retroviruses, known as endogenous retroviruses related to Jaagsiekte sheep retrovirus or enJSRVs, are critical during the early phase of pregnancy when the placenta begins to develop.
Share:
FULL STORY

A team of scientists from Texas A&M University and The University of Glasgow Veterinary School in Scotland has discovered that naturally occurring endogenous retroviruses are required for pregnancy in sheep.

advertisement

In particular, a class of endogenous retroviruses, known as endogenous retroviruses related to Jaagsiekte sheep retrovirus or enJSRVs, are critical during the early phase of pregnancy when the placenta begins to develop.

Retroviruses, such as human immunodeficiency virus or HIV, are one class of viruses. They are best known for their ability to cause diseases, said Dr. Thomas Spencer, a reproductive biologist with the Texas Agricultural Experiment Station and Texas A&M University.

Findings published Sept. 11 in the Proceedings of the National Academy of Sciences demonstrate enJSRVs are essential for the development of the placenta in sheep.

Retroviruses are unique for their ability to permanently insert their genetic material into the DNA of host cells, he said. During evolution of mammals, some retroviruses infected the germline (cells of the ovary and testis that have genetic material that are passed to their offspring) of the host, which is then inherited by their children. These retroviruses, known as endogenous retroviruses, are present in the genome of all mammals, including humans. Consequently, endogenous retroviruses can be considered remnants of ancient retroviral infections, Spencer said.

Many scientists believed these endogenous retroviruses were junk DNA, he said.

advertisement

"Indeed, these endogenous retroviruses are usually harmless and generally contain mutations that prevent them from producing infectious retroviruses," he said.

However, several endogenous retroviruses appear to provide protection from infection and are involved in reproduction. For instance, the exogenous Jaagsiekte Sheep Retrovirus or JSRV causes lung tumors in sheep and led to the death of Dolly, the world's first mammal cloned from an adult cell.

The idea that endogenous retroviruses are important for reproduction in mammals has been around for about 30 years, Spencer said. Studies in cultured cells have shown that a protein of a human endogenous retrovirus might have a role in development of the human placenta.

The team blocked expression of the envelope of the enJSRVs using morpholino antisense oligonucleotides, which inhibit translation of specific messenger RNA. When production of the envelope protein was blocked in the early placenta, the growth of the placenta was reduced and a certain cell type, termed giant binucleate cells, did not develop.

The result was that embryos could not implant and the sheep miscarried, Spencer said.

advertisement

Miscarriage is a serious medical problem for all mammals, including humans.

"Our research supports the idea that endogenous retroviruses shaped the evolution of the placenta in mammals and then became indispensable for pregnancy, and thus may be why they are expressed in the placenta of many mammals," he said.

Further, Palmarini said, "The enJSRVs arose from ancient infections of small ruminants during their evolution," said Dr. Massimo Palmarini, a virologist at The University of Glasgow Veterinary School. "This infection was beneficial to the host and was then positively selected for during evolution. In other words, animals with enJSRVs were better equipped than those without. Therefore, enJSRVs became a permanent part of the sheep genome and, in these days, sheep can't do without them."

The research team is trying to determine exactly how enJSRVs function in development of the sheep placenta. Their results should have implications for both human health and animal production.

The team was led by Spencer and Palmarini. Team members are Kathrin Dunlap, Robert Burghardt, Kanako Hayashi and Jennifer Farmer at Texas A&M, and Mariana Varela at The University of Glasgow Veterinary School.

The work of the research team has been funded by the Wellcome Trust in the United Kingdom and the National Institutes of Health in the U.S.

make a difference: sponsored opportunity

Story Source:

Materials provided by Texas A&M University - Agricultural Communications. Note: Content may be edited for style and length.


Cite This Page:

  • MLA
  • APA
  • Chicago
Texas A&M University - Agricultural Communications. "Researchers Discover That Sheep Need Retroviruses For Reproduction." ScienceDaily. ScienceDaily, 11 September 2006. <www.sciencedaily.com/releases/2006/09/060911233630.htm>.
Texas A&M University - Agricultural Communications. (2006, September 11). Researchers Discover That Sheep Need Retroviruses For Reproduction. ScienceDaily. Retrieved October 21, 2022 from www.sciencedaily.com/releases/2006/09/060911233630.htm
Texas A&M University - Agricultural Communications. "Researchers Discover That Sheep Need Retroviruses For Reproduction." ScienceDaily. www.sciencedaily.com/releases/2006/09/060911233630.htm (accessed October 21, 2022).

  • RELATED TOPICS
    • Plants & Animals
      • Veterinary Medicine
      • Mammals
      • Biology
      • Genetics
      • Biotechnology
      • Evolutionary Biology
      • Microbes and More
      • Animals
advertisement

  • RELATED TERMS
    • Domestic sheep
    • Bighorn Sheep
    • Marsupial
    • Tree
    • Dolly the Sheep
    • Placenta
    • Abalone
    • Ranching
advertisement

  Print   Email   Share

advertisement

1

2

3

4

5
Most Popular
this week

PLANTS & ANIMALS
Eating Late Increases Hunger, Decreases Calories Burned, and Changes Fat Tissue
Dogs Can Smell When We're Stressed, Study Suggests
A New Species of Deep-Sea Fish Discovered in the Atacama Trench
EARTH & CLIMATE
Battery Tech Breakthrough Paves Way for Mass Adoption of Affordable Electric Car
Dinosaur-Killing Asteroid Triggered Global Tsunami That Scoured Seafloor Thousands of Miles from Impact Site
Collision May Have Formed the Moon in Mere Hours, Simulations Reveal
FOSSILS & RUINS
Learning About the First Animals on Earth from Life at the Poles
Reign of Papua New Guinea Highland's Megafauna Lasted Long After Humans Arrived
How Fluctuating Oxygen Levels May Have Accelerated Animal Evolution
advertisement

Strange & Offbeat
 

PLANTS & ANIMALS
Chimpanzees Synchronize Their Steps Just Like Humans
Secrets of Namibia's Fairy Circles Demystified: Plants Self-Organize
Tardigrades: Microscopic Creatures' Amazing Durability
EARTH & CLIMATE
Looking to Move to a Galaxy Far, Far Away? Innovative System Evaluates Habitability of Distant Planets
Chimpanzees Synchronize Their Steps Just Like Humans
Methane-Eating 'Borgs' Have Been Assimilating Earth's Microbes
FOSSILS & RUINS
Dinosaur 'Mummies' Might Not Be as Unusual as We Think
Reign of Papua New Guinea Highland's Megafauna Lasted Long After Humans Arrived
Sound Reveals Giant Blue Whales Dance With the Wind to Find Food
Explore More
from ScienceDaily

RELATED STORIES

Widespread Variation of Inherited Retroviruses Among Darwin’s Finches
Oct. 14, 2022 — Vertebrate genomes are repositories for retrovirus code that was deposited into germ line as inherited endogenous retroviruses during evolution. Researchers now provide new findings about retroviral ...
New Inherited Retroviruses Identified in the Koala Genome
June 13, 2022 — Historic virus infections can be traced in vertebrate genomes. For millions of years, these genomes have been repositories for retroviruses that incorporated their code into germline cells and were ...
Ancient Viral Elements Embedded in Human Genome Not from Fossil Retrovirus
May 27, 2022 — Many types of animals, including humans, successfully coexist with retroviruses, and we know that ancient retrovirus viral elements can even be found within our genome. We also know that these ...
New Knowledge About Retrovirus-Host Coevolution
Oct. 9, 2018 — Retroviruses have colonized vertebrate hosts for millions of years by inserting their genes into host genomes, enabling their inheritance through generations as endogenous retroviruses (ERVs). ...
advertisement


SD
  • SD
    • Home Page
    • Top Science News
    • Latest News
  • Home
    • Home Page
    • Top Science News
    • Latest News
  • Health
    • View all the latest top news in the health sciences,
      or browse the topics below:
      Health & Medicine
      • Allergy
      • Alternative Medicine
      • Birth Control
      • Cancer
      • Diabetes
      • Diseases
      • Heart Disease
      • HIV and AIDS
      • Obesity
      • Stem Cells
      • ... more topics
      Mind & Brain
      • ADD and ADHD
      • Addiction
      • Alzheimer's
      • Autism
      • Depression
      • Headaches
      • Intelligence
      • Psychology
      • Relationships
      • Schizophrenia
      • ... more topics
      Living Well
      • Parenting
      • Pregnancy
      • Sexual Health
      • Skin Care
      • Men's Health
      • Women's Health
      • Nutrition
      • Diet and Weight Loss
      • Fitness
      • Healthy Aging
      • ... more topics
  • Tech
    • View all the latest top news in the physical sciences & technology,
      or browse the topics below:
      Matter & Energy
      • Aviation
      • Chemistry
      • Electronics
      • Fossil Fuels
      • Nanotechnology
      • Physics
      • Quantum Physics
      • Solar Energy
      • Technology
      • Wind Energy
      • ... more topics
      Space & Time
      • Astronomy
      • Black Holes
      • Dark Matter
      • Extrasolar Planets
      • Mars
      • Moon
      • Solar System
      • Space Telescopes
      • Stars
      • Sun
      • ... more topics
      Computers & Math
      • Artificial Intelligence
      • Communications
      • Computer Science
      • Hacking
      • Mathematics
      • Quantum Computers
      • Robotics
      • Software
      • Video Games
      • Virtual Reality
      • ... more topics
  • Enviro
    • View all the latest top news in the environmental sciences,
      or browse the topics below:
      Plants & Animals
      • Agriculture and Food
      • Animals
      • Biology
      • Biotechnology
      • Endangered Animals
      • Extinction
      • Genetically Modified
      • Microbes and More
      • New Species
      • Zoology
      • ... more topics
      Earth & Climate
      • Climate
      • Earthquakes
      • Environment
      • Geography
      • Geology
      • Global Warming
      • Hurricanes
      • Ozone Holes
      • Pollution
      • Weather
      • ... more topics
      Fossils & Ruins
      • Ancient Civilizations
      • Anthropology
      • Archaeology
      • Dinosaurs
      • Early Humans
      • Early Mammals
      • Evolution
      • Lost Treasures
      • Origin of Life
      • Paleontology
      • ... more topics
  • Society
    • View all the latest top news in the social sciences & education,
      or browse the topics below:
      Science & Society
      • Arts & Culture
      • Consumerism
      • Economics
      • Political Science
      • Privacy Issues
      • Public Health
      • Racial Disparity
      • Religion
      • Sports
      • World Development
      • ... more topics
      Business & Industry
      • Biotechnology & Bioengineering
      • Computers & Internet
      • Energy & Resources
      • Engineering
      • Medical Technology
      • Pharmaceuticals
      • Transportation
      • ... more topics
      Education & Learning
      • Animal Learning & Intelligence
      • Creativity
      • Educational Psychology
      • Educational Technology
      • Infant & Preschool Learning
      • Learning Disorders
      • STEM Education
      • ... more topics
  • Quirky
    • Top News
    • Human Quirks
    • Odd Creatures
    • Bizarre Things
    • Weird World
Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

  • Email Newsletters
  • RSS Feeds
Follow Us

Keep up to date with the latest news from ScienceDaily via social networks:

  • Facebook
  • Twitter
  • LinkedIn
Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?

  • Leave Feedback
  • Contact Us
About This Site  |  Staff  |  Reviews  |  Contribute  |  Advertise  |  Privacy Policy  |  Editorial Policy  |  Terms of Use
Copyright 1995-2022 ScienceDaily or by other parties, where indicated. All rights controlled by their respective owners.
Content on this website is for information only. It is not intended to provide medical or other professional advice.
Views expressed here do not necessarily reflect those of ScienceDaily, its staff, its contributors, or its partners.
Financial support for ScienceDaily comes from advertisements and referral programs, where indicated.
— CCPA: Do Not Sell My Information — GDPR: Privacy Settings —