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201605May08:29

Stem-​cell plan to save the north­ern white rhi­noc­eros – crazy or not?

Infor­ma­tion
pub­lished 05 May 2016 | mod­i­fied 05 May 2016
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Northern white rhino at Dvur Kralove ZooIn Decem­ber 2015 an inter­na­tional group of sci­en­tists con­vened in Vienna, Aus­tria, to dis­cuss the immi­nent extinc­tion of the north­ern white rhi­noc­eros and the pos­si­bil­ity of bring­ing the species back from the brink of extinc­tion. The dis­cus­sions of this his­toric meet­ing are pub­lished online on 3 May in the inter­na­tional Jour­nal Zoo Biol­ogy. The pub­lic release of this work is designed as part of the ongo­ing effort to raise aware­ness for the extinc­tion cri­sis that rhi­nos and many other species are fac­ing while also reach­ing out to the sci­en­tific com­mu­nity to share and gather information.

The effort to save the north­ern white rhi­noc­eros will need new tech­nolo­gies, new approaches and problem-​solving in order to avert its immi­nent extinction
Joseph Sara­gusty, androl­o­gist from the Leib­niz Insti­tute for Zoo and Wildlife Research (IZW) in Berlin, Germany »

The pro­duc­tive engage­ment of an inter­na­tional mul­ti­dis­ci­pli­nary team of experts will be essen­tial to accom­plish the ambi­tious goal of bring­ing back the north­ern white rhi­noc­eros from its oth­er­wise cer­tain path to extinc­tion,” Sara­gusty added.

In the wild, the north­ern white rhi­nos (Cer­a­totherium simum cot­toni) were poached to extinc­tion. Their slaugh­ter has been dri­ven by the demand for their horn in some coun­tries of East Asia and the Ara­bian Penin­sula. The sub­species is listed as Crit­i­cally Endan­gered accord­ing to the IUCN Red List of Threat­ened Species™, when assessed in 2011.

The dis­cus­sion to save the north­ern white rhi­noc­eros touches on genet­ics and cell biol­ogy, sci­en­tific ethics and the impor­tance of long term strate­gic think­ing and ongo­ing com­mu­ni­ca­tions. A key ele­ment of these dis­cus­sions was the need to main­tain genetic banks of frozen tis­sue, sper­ma­to­zoa and oocytes to use as mate­ri­als in this fight against extinction.

Cry­obanked genetic resources from this unique form of rhi­noc­eros have been saved in San Diego and in Europe”, said Oliver Ryder, geneti­cist for San Diego Zoo Global. “The genetic resources in the form of banked viable cell cul­tures, tis­sues and sper­ma­to­zoa, together with the capa­bil­ity to estab­lish induced pluripo­tent stem cells are the basis for hope that a viable pop­u­la­tion of north­ern white rhi­noc­eros can be produced.”

With some genetic tis­sue from north­ern white rhi­nos avail­able the group is look­ing at advanced repro­duc­tive tech­nolo­gies as the hope for the future of the species.

Rhino preservationFlow dia­gram detail­ing the var­i­ous options dis­cussed dur­ing the “Con­ser­va­tion by Cel­lu­lar Tech­nolo­gies” meet­ing that took place in Vienna in Decem­ber 2015. Detailed are the resources and flow of the process using nat­ural gametes (right side of the dia­gram) or con­structed gametes (left side of the dia­gram), lead­ing even­tu­ally, so we hope, to live birth of a north­ern white rhi­noc­eros (NWR) and later on to a viable and self sus­tain­ing NWR pop­u­la­tion. SWR, south­ern white rhi­noc­eros; KOGR, knock­out gene replace­ment; PM, post mortem; IVF, in vitro fer­til­iza­tion; ICSI, intra­cy­to­plas­mic sperm injec­tion; iPSCs, induced pluripo­tent stem cells; PGCs, pri­mor­dial germ cells; ICM, inner cell mass.
Image credit: Sara­gusty, J., Diecke, S., Drukker, M., Dur­rant, B., Friedrich Ben-​Nun, I., Galli, C., Göritz, F., Hayashi, K., Her­mes, R., Holtze, S., John­son, S., Laz­zari, G., Loi, P., Lor­ing, J. F., Okita, K., Ren­free, M. B., Seet, S., Voracek, T., Ste­jskal, J., Ryder, O. A. and Hilde­brandt, T. B. (2016), Rewind­ing the process of mam­malian extinc­tion. Zoo Biol­ogy. doi:10.1002/zoo.21284.

It was a long way from the idea to the roadmap cre­ated in Vienna. I am glad that we found so many com­pe­tent sup­port­ers in the sci­en­tific com­mu­nity who believe in the appli­ca­tion of advanced cel­lu­lar and repro­duc­tive tech­nolo­gies for the genetic res­cue of the north­ern white rhi­noc­eros. Now we have to demon­strate that this novel strat­egy can make a dif­fer­ence”, said Thomas Hilde­brandt, head of the Repro­duc­tion Man­age­ment depart­ment at IZW.

The last three north­ern white rhi­noc­er­oses reside in Ol Pejeta Con­ser­vancy in Kenya where they were trans­ported from ZOO Dvůr Králové, Czech Repub­lic. “Although we were able to breed the north­ern white rhi­noc­er­oses in our zoo, their health sta­tus does not allow them to breed nat­u­rally any­more. We are now opti­mistic that the cutting-​edge research out­lined in Vienna will give these very last spec­i­mens a chance to see an off­spring of their own kind”, said Jan Ste­jskal, Direc­tor of Inter­na­tional Projects of ZOO Dvůr Králové.

In addi­tion to shar­ing infor­ma­tion about repro­duc­tive tech­nolo­gies the group of experts dis­cussed the ethics of spend­ing resources to save one species. The paper voices the hope that the infor­ma­tion gath­ered through this effort would be applied towards other species fac­ing the threat of extinc­tion in the future.

But not all are in favour

They should not be push­ing this idea that they’re sav­ing a species. If you want to save a [rhino] species, put your money into south­ern white conservation
« Michael Knight, chair of the Inter­na­tional Union for Con­ser­va­tion of Nature’s African Rhino Spe­cial­ist Group

Knight is wor­ried that the effort of the costly ‘Star Trek-​type’ sci­en­tific exper­i­ment will divert money from other rhino con­ser­va­tion efforts. Espe­cially money that could sus­tain the already good results with south­ern white rhi­nos, whose num­bers are swelling thanks to good management.

And isn’t the south­ern white rhino not as equally impor­tant to the ecosys­tem as the north­ern white rhino? In other words it could replace the north­ern white rhino, which more or less already shold be con­sid­ered extinct [Moos].


(Source: Leib­niz Insti­tute for Zoo and Wildlife Research press release, 03.05.2016; Nature news, 03.05.2016)


Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

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