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<div>Hi Leon, </div>
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<div>I have about a dozen female X. laevis that are >27 years old, still being used occasionally for oocytes. They were part of a NASA breeding project in John Gerhart’s lab to produce “flight-quality” eggs for the space shuttle, therefore their birthday was
around 1988. It is possible John can provide a more accurate birthdate. Some of them were tattooed via liquid-nitrogen branding, but the pigmentless numbers faded with time. However, due to their gigantic size (and consequent difficulty for staff to handle
for squeezing eggs), these frogs have long been isolated from our smaller, younger females. I cannot guarantee that a few other large, old frogs might not have joined them in the old ladies’ tank over time, but I’m confident most of them share the above history. </div>
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<div>They have been across the country twice: as young adults (therefore >2 years old already) from NASA Ames Research Center (via Berkeley) to my lab at Wesleyan in CT in ~1990, and then back to the W. coast (Portland) in 1993. Are you interested in booking
them passage for a third trip back East? Or do you need particular tissues/eggs/oocytes shipped? I would be delighted to have an excuse to free up their tank, but so far haven’t found the heart to pull their plug.</div>
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<div>FWIW, last year one of them was found at ovariectomy to have become 100% atretic (all fat body, no recognizable ovary, otherwise perfectly healthy). The others still produce eggs copiously, and a physiologist here at OHSU likes their oocytes for membrane
channel expression studies.</div>
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<div>Mike Danilchik</div>
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<span style="font-weight:bold">From: </span><<a href="mailto:xenopus-bounces@lists.mbl.edu">xenopus-bounces@lists.mbl.edu</a>> on behalf of Leon Peshkin <<a href="mailto:peshkin@gmail.com">peshkin@gmail.com</a>><br>
<span style="font-weight:bold">Date: </span>Monday, May 15, 2017 at 11:38 AM<br>
<span style="font-weight:bold">To: </span>"<a href="mailto:xenopus@lists.mbl.edu">xenopus@lists.mbl.edu</a>" <<a href="mailto:xenopus@lists.mbl.edu">xenopus@lists.mbl.edu</a>><br>
<span style="font-weight:bold">Subject: </span>[Xenopus] old Xenopus animals<br>
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<div>Dear Xenopus Community,<br>
we are interested in obtaining old animals to try using Xenopus in a project related to biology of aging. Ideally X. laevis, but any Xenopus should do.<br>
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People tend to only keep around younger animals for obvious reasons but perhaps someone knows of a lab where older animals of recorded age are kept around ?<br>
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<div> Also any reliable information on natural life-span in Xenopus<br>
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<div>with a large sample size would be very helpful. <br>
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any information related to this would be greatly appreciated. <br>
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-Leon Peshkin <br>
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