{"58065":{"#nid":"58065","#data":{"type":"news","title":"Study Documents Use of Hormone Progesterone in Simple Aquatic Animals","body":[{"value":"\u003Cp\u003EA new study shows that humans and tiny aquatic animals known as rotifers have something important in common when it comes to sex.\u003C\/p\u003E\u003Cp\u003EBarely visible without a microscope, rotifers eat algae and serve primarily as food for baby fish. But the females of certain rotifer species can do something quite unusual: they can reproduce asexually by creating clones of themselves, or they can initiate a process that allows sexual reproduction by producing male rotifers. \u003C\/p\u003E\u003Cp\u003EThe chemical mediator for this change from asexual to sexual reproduction turns out to be progesterone \u2013 a simple molecule that also plays a vital role in regulating reproduction and sexual development in humans and many other species. Finding this sex steroid and its receptor in simple rotifers suggests that the progesterone signaling technique dates back hundreds of millions of years. \u003C\/p\u003E\u003Cp\u003E\u201cThis has really important evolutionary implications,\u201d said Julia Kubanek, an associate professor in the School of Biology at the Georgia Institute of Technology and one of the study\u2019s principal authors. \u201cOur study shows that the identical steroid molecule found in humans and rotifers is used for two very different aspects of reproduction.\u201d \u003C\/p\u003E\u003Cp\u003ESponsored by the National Science Foundation, the research was published June 14, 2010, in the early online edition of the journal \u003Cem\u003EProceedings of the National Academy of Sciences\u003C\/em\u003E. The study is believed to be the first to document the use of progesterone in the lineage of simple animals that includes rotifers \u2013 and has been largely unchanged for millions of years. \u003C\/p\u003E\u003Cp\u003EMost animals reproduce sexually, a method that makes a species more adaptable by facilitating the elimination of bad genes and creating potentially beneficial new gene combinations. Very simple organisms, such as bacteria, reproduce through cell division and obtain new genetic material from the environment. \u003C\/p\u003E\u003Cp\u003EThe rotifer species \u003Cem\u003EBrachionus manjavacas \u003C\/em\u003Eis somewhere in between. During most of the year, the rotifer population consists only of females, which reproduce by creating clones of themselves. But when unfavorable environmental conditions threaten \u2013 such as the loss of algae food \u2013 about a third of the rotifer population switches to sexual reproduction, which is the only way the creatures can produce eggs able to survive through a long winter. \u003C\/p\u003E\u003Cp\u003EKubanek and her collaborators wanted to understand what was triggering that change, which begins with the production of male rotifers. The switching appears to depend on a pheromone protein that the rotifers release into the water to indicate that other rotifers are nearby. When the rotifer population grows large enough to create a significant concentration of that protein, females start laying eggs that can develop as males. A population large enough to do that usually doesn\u2019t build up until fall in North America \u2013 when winter and the end of the algae food supply are near. \u003C\/p\u003E\u003Cp\u003E\u201cThe rotifers are pretty good at figuring out when conditions are getting bad and when it\u2019s time to produce males, have sex, make these overwintering eggs and call it a day,\u201d Kubanek said. \u201cThey are really making some fairly sophisticated decisions about when to have sex, and when to go it alone.\u201d \u003C\/p\u003E\u003Cp\u003ETo understand the complex process, the researchers combined several different research techniques to piece the puzzle together. \u003C\/p\u003E\u003Cp\u003EProfessor Terry Snell in Georgia Tech\u2019s School of Biology, along with his students and collaborators at Woods Hole Oceanographic Institution, studied the partially-sequenced genome of the rotifer and located a receptor for a progesterone-like molecule. Then, using a fluorescent probe developed by James La Clair of the Xenobe Research Institute in San Diego, Paige Stout, a Ph.D. student in Georgia Tech\u2019s School of Chemistry and Biochemistry showed that progesterone binds to a receptor in the reproductive systems of female rotifers. \u003C\/p\u003E\u003Cp\u003EThe researchers gained further evidence of progesterone receptor\u2019s presence through the use of affinity chromatography, which used the same probe system to extract the receptor from a mixture of proteins contained in the rotifers. Further, mass spectrometry indicated the presence of progesterone at parts-per-billion levels in rotifer mass. \u003C\/p\u003E\u003Cp\u003EFinally, Snell and School of Biology research scientist Tonya Shearer demonstrated a direct connection between the hormone and the switch to sexual reproduction in the rotifers. They used RNA interference (RNAi) technology to silence the gene controlling the progesterone receptor, which reduced by nearly two-thirds the number of animals switching over to sexual reproduction in response to the progesterone signal. \u003C\/p\u003E\u003Cp\u003E\u201cThis suggests that progesterone is important in this switch from asexual to sexual reproduction,\u201d Stout said. \u201cProgesterone is certainly involved in the process, though there may be more going on in a cascade process that we haven\u2019t yet seen.\u201d \u003C\/p\u003E\u003Cp\u003EBeyond explaining how chemical signaling mechanisms crucial to both rotifers and humans evolved over time, the research can also help researchers understand the interplay between the environment, metabolism, hormones and behaviors. \u003C\/p\u003E\u003Cp\u003E\u201cWe can learn things from working with rotifers that touch upon human biology, including \u2013 in this case \u2013 the universality of steroids in reproduction and how steroids are used differently in different animals,\u201d Kubanek said. \u201cWhen we experiment with rotifers in the lab, we can manipulate their behavior, physiology and metabolic pathways to determine how these steroids are made and used.\u201d \u003C\/p\u003E\u003Cp\u003EThough the researchers were looking for progesterone in the rotifers, finding the same molecule that is essential to humans still came as a surprise. \u003C\/p\u003E\u003Cp\u003E\u201cIt\u2019s a very complex system for such a simple organism,\u201d said Stout, whose primary research focuses on complex potential pharmaceutical compounds produced by marine organisms such as seaweeds. \u201cThough we were certainly looking for it, I was surprised to see progesterone and not some derivative of it.\u201d \u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis research was supported by National Science Foundation grant BE\/GenEn MCB-0412674. Any opinions, findings, conclusions or recommendations expressed in this article are those of the researchers and do not necessarily reflect the views of the National Science Foundation.\u003C\/em\u003E \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003EGeorgia Institute of Technology\u003Cbr \/\u003E75 Fifth Street, N.W., Suite 314\u003Cbr \/\u003EAtlanta, Georgia 30308 USA\u003C\/strong\u003E \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: John Toon (404-894-6986)(\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E) or Abby Vogel Robinson (404-385-3364)(\u003Ca href=\u0022mailto:abby@innovate.gatech.edu\u0022\u003Eabby@innovate.gatech.edu\u003C\/a\u003E). \u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E: John Toon \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EA new study shows that humans and tiny aquatic animals known as rotifers have something important in common when it comes to sex. Both use the hormone progesterone for chemical signalling.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Study shows that humans and rotifers both use the same hormone."}],"uid":"27303","created_gmt":"2010-06-14 00:00:00","changed_gmt":"2016-10-08 03:06:47","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2010-06-14T00:00:00-04:00","iso_date":"2010-06-14T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"58066":{"id":"58066","type":"image","title":"Female rotifer","body":null,"created":"1449176194","gmt_created":"2015-12-03 20:56:34","changed":"1475894510","gmt_changed":"2016-10-08 02:41:50","alt":"Female rotifer","file":{"fid":"190755","name":"txe40165.jpg","image_path":"\/sites\/default\/files\/images\/txe40165_0.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/txe40165_0.jpg","mime":"image\/jpeg","size":175417,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/txe40165_0.jpg?itok=_fCjh6P4"}},"58067":{"id":"58067","type":"image","title":"Microscope study of rotifers","body":null,"created":"1449176194","gmt_created":"2015-12-03 20:56:34","changed":"1475894510","gmt_changed":"2016-10-08 02:41:50","alt":"Microscope study of rotifers","file":{"fid":"190756","name":"tpf40165.jpg","image_path":"\/sites\/default\/files\/images\/tpf40165_0.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/tpf40165_0.jpg","mime":"image\/jpeg","size":985754,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/tpf40165_0.jpg?itok=AmpcLCPe"}},"58068":{"id":"58068","type":"image","title":"Researcher with microscope","body":null,"created":"1449176194","gmt_created":"2015-12-03 20:56:34","changed":"1475894510","gmt_changed":"2016-10-08 02:41:50","alt":"Researcher with microscope","file":{"fid":"190757","name":"ttx40165.jpg","image_path":"\/sites\/default\/files\/images\/ttx40165_0.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/ttx40165_0.jpg","mime":"image\/jpeg","size":932118,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/ttx40165_0.jpg?itok=1Pzu7NP5"}}},"media_ids":["58066","58067","58068"],"related_links":[{"url":"http:\/\/www.biology.gatech.edu\/","title":"School of Biology"},{"url":"http:\/\/www.biology.gatech.edu\/people\/index.php?id=julia-kubanek","title":"Julia Kubanek"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"146","name":"Life Sciences and Biology"},{"id":"135","name":"Research"}],"keywords":[{"id":"2398","name":"hormone"},{"id":"9869","name":"progesterone"},{"id":"9871","name":"reproduction"},{"id":"170997","name":"signalling"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}