{"id":123188,"date":"2024-11-07T19:21:25","date_gmt":"2024-11-07T12:21:25","guid":{"rendered":"https:\/\/hotvideos24.online\/?p=123188"},"modified":"2024-11-07T19:21:25","modified_gmt":"2024-11-07T12:21:25","slug":"wild-discovery-reveals-that-comb-jellies-can-age-in-reverse-sciencealert","status":"publish","type":"post","link":"https:\/\/hotvideos24.online\/?p=123188","title":{"rendered":"Wild Discovery Reveals That Comb Jellies Can Age in Reverse : ScienceAlert"},"content":{"rendered":"<p> <script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<\/p>\n<div>\n<p>When things get tough in adulthood, it might seem appealing to return to simpler times.<\/p>\n<p>One bizarre marine creature has taken this approach to dire situations quite literally, regressing its physical adult body to a juvenile stage once the stress of starvation or injury has subsided.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>Until now, the immortal jellyfish (<span><a href=\"https:\/\/en.wikipedia.org\/wiki\/Turritopsis_dohrnii\"><em>Turritopsis dohrnii<\/em><\/a>) was the only species thought to be able to <a href=\"https:\/\/www.sciencealert.com\/the-immortal-jellyfish-can-age-in-reverse-and-possibly-live-forever\">wind back the clock<\/a> on jelly-puberty like this, but now it&#8217;s joined by <a href=\"https:\/\/en.wikipedia.org\/wiki\/Mnemiopsis\"><i>Mnemiopsis leidyi<\/i>,<\/a> better known as the sea walnut or the warty comb jelly. <\/span><\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>We already knew comb jellies were pretty special: Their regeneration abilities <a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC8228598\/\">are unmatched<\/a>, they can <a href=\"https:\/\/www.sciencealert.com\/these-freakish-ocean-creatures-can-combine-as-one-when-injured\">fuse together<\/a> to survive major injuries, they <a href=\"https:\/\/www.sciencealert.com\/this-animal-s-butt-appears-when-needed-and-it-could-help-us-understand-how-ours-evolved\">only form a butthole when they actually need it<\/a>, and with total disregard for the usual rules of biology, they can <a href=\"https:\/\/www.pnas.org\/doi\/full\/10.1073\/pnas.2122052119\">reproduce sexually<\/a> in their <a href=\"https:\/\/www.pnas.org\/doi\/full\/10.1073\/pnas.2218317120\">so-called larval stage<\/a>.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p><a href=\"https:\/\/academic.oup.com\/plankt\/article-abstract\/37\/5\/1011\/1552108\">Previous studies<\/a> had also observed <em>M. leidyi <\/em>reducing its size and body mass considerably during starvation as a way of surviving leaner times, but <a href=\"https:\/\/academic.oup.com\/plankt\/article-abstract\/37\/5\/1006\/1554269\">experiments<\/a> ruled out reverse-aging under these conditions.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>Marine biologist Joan Soto-Angel, from the University of Bergen in Norway, was confused when an adult sea walnut he was keeping in a laboratory tank, with its plump gelatinous lobes that define adulthood in this species, suddenly disappeared. In its place pulsed a larva, more walnut-shell-shaped than any adult of its kind.<\/p>\n<figure id=\"attachment_142266\" aria-describedby=\"caption-attachment-142266\" style=\"width: 2954px\" class=\"wp-caption alignnone\"><img decoding=\"async\" src=\"https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672.jpg\" alt=\"diagram shows comb jelly life cycle can go forward and reverse\" width=\"2954\" height=\"2927\" class=\"wp-image-142266 size-full\" srcset=\"https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672.jpg 2954w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672-642x636.jpg 642w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672-419x415.jpg 419w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672-768x761.jpg 768w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672-1536x1522.jpg 1536w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672-2048x2029.jpg 2048w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-1-e1730354866672-600x595.jpg 600w\" sizes=\"auto, (max-width: 2954px) 100vw, 2954px\" loading=\"lazy\"\/><figcaption id=\"caption-attachment-142266\" class=\"wp-caption-text\">The life cycle of the sea walnut comb jelly is not as straightforward as we thought. <span>Illustrations of the different life stages by Nicholas Bezio. (Soto-Angel and Burkhardt, <a href=\"https:\/\/doi.org\/10.1073\/pnas.2411499121\"><em>PNAS<\/em><\/a>, 2024)<\/span><\/figcaption><\/figure>\n<p>He sensed the existing research might not be the full story, and so in collaboration with Michael Sars Center colleague, <span>Pawel Burkhardt, set out to check whether this jelly had somehow <a href=\"https:\/\/www.youtube.com\/watch?v=WlM7nm3TLnY\">pressed rewind<\/a> on aging.<\/span><\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>They kept 65 healthy adult comb jellies isolated in tanks, all of which had completely reabsorbed the tentacles of their youth, another defining feature of their maturity.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>All were starved for 15 days, and then fed once a week with a small amount of <a href=\"https:\/\/en.wikipedia.org\/wiki\/Brachionus\">rotifers,<\/a> a much leaner diet than usual, and as expected, began to quickly shrink.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>When their adult lobes began to &#8216;reabsorb&#8217; into their diminishing bodies, feeding was resumed every second day. And Soto-Angel knew he was onto something.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>Fifteen of these jellies also had lobes surgically removed at the start of the experiment, adding a further stressor that the previous experiments hadn&#8217;t captured.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p><span>&#8220;Over several weeks, they not only reshaped their morphological features, but also had a completely different feeding behavior, typical of a cydippid larva,&#8221; Soto-Angel <a href=\"https:\/\/www.uib.no\/en\/michaelsarscentre\/173833\/young-again-study-shows-comb-jellies-can-age-reverse\">says<\/a>. <\/span><\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p><span>&#8220;Witnessing how they slowly transition to a typical cydippid larva, as if they were going back in time, was simply fascinating.&#8221;<\/span><\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p>The experiment showed the jellyfish could revert to a youthful form when stressed only by starvation, but this was far less common than in the lobectomy group: Only seven of the 50 starved jellies fully reverted, while six out of the fifteen injured animals were the jelly equivalent of &#8217;17 again&#8217;.<\/p>\n<figure id=\"attachment_142269\" aria-describedby=\"caption-attachment-142269\" style=\"width: 4112px\" class=\"wp-caption alignnone\"><img decoding=\"async\" src=\"https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2.jpg\" alt=\"time series photos of 2 starved and one lobectomized sea jelly. the lobectomized jelly reverts to larva by day 15. the other two revert by day 41 and 43 respectively.\" width=\"4112\" height=\"2927\" class=\"wp-image-142269 size-full\" srcset=\"https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2.jpg 4112w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2-642x457.jpg 642w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2-583x415.jpg 583w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2-768x547.jpg 768w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2-1536x1093.jpg 1536w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2-2048x1458.jpg 2048w, https:\/\/www.sciencealert.com\/images\/2024\/10\/pnas.2411499121fig02-2-600x427.jpg 600w\" sizes=\"auto, (max-width: 4112px) 100vw, 4112px\" loading=\"lazy\"\/><figcaption id=\"caption-attachment-142269\" class=\"wp-caption-text\">Individual trajectories and morphological changes during reverse development for three <em>M. leidyi<\/em> specimens. Scale bar: 5 mm for Day 0; all others 2 mm. (Soto-Angel and Burkhardt, <a href=\"https:\/\/doi.org\/10.1073\/pnas.2411499121\"><em>PNAS<\/em><\/a>, 2024)<\/figcaption><\/figure>\n<p>This also means many of the juvenile jellies in experiments and records might not have been as youthful as they seemed.<\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p><span>&#8220;It will be interesting to reveal the molecular mechanism driving reverse development, and what happens to the animal&#8217;s nerve net during this process,&#8221; <a href=\"https:\/\/www.uib.no\/en\/michaelsarscentre\/173833\/young-again-study-shows-comb-jellies-can-age-reverse\">says<\/a> collaborator Pawel Burkhardt, who is leading investigations into the <a href=\"https:\/\/www.uib.no\/en\/michaelsarscentre\/114773\/burkhardt-group\">evolutionary origins of neurons<\/a>. <\/span><\/p>\n<p><!-- START single\/mrec --><br \/>\n<!-- END single\/mrec --><\/p>\n<p><span>&#8220;The fact that we have found a new species that uses this peculiar &#8216;time-travel machine&#8217; raises fascinating questions about how spread this capacity is across the animal tree of life,&#8221; Soto-Angel <a href=\"https:\/\/www.uib.no\/en\/michaelsarscentre\/173833\/young-again-study-shows-comb-jellies-can-age-reverse\">says<\/a>.<\/span><\/p>\n<p>This research was published in <a href=\"https:\/\/doi.org\/10.1073\/pnas.2411499121\"><em>Proceedings of the National Academy of Sciences<\/em><\/a>.<\/p>\n<\/p><\/div>\n<p><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<br \/><div data-type=\"_mgwidget\" data-widget-id=\"1660802\">\r\n<\/div>\r\n<script>(function(w,q){w[q]=w[q]||[];w[q].push([\"_mgc.load\"])})(window,\"_mgq\");\r\n<\/script>\r\n<br \/>\n<br \/><a href=\"https:\/\/www.sciencealert.com\/wild-discovery-reveals-that-comb-jellies-can-age-in-reverse\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>When things get tough in adulthood, it might seem appealing to return to simpler times. One bizarre marine creature has taken this approach to dire situations quite literally, regressing its &hellip; <a href=\"https:\/\/hotvideos24.online\/?p=123188\" class=\"more-link\">Read More<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8628],"tags":[],"class_list":["post-123188","post","type-post","status-publish","format-standard","hentry","category-science","entry"],"_links":{"self":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/123188","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=123188"}],"version-history":[{"count":0,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/123188\/revisions"}],"wp:attachment":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=123188"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=123188"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=123188"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}