{"id":721,"date":"2018-05-02T16:53:45","date_gmt":"2018-05-02T16:53:45","guid":{"rendered":"http:\/\/uni.hi.is\/apalsson\/?p=721"},"modified":"2018-05-02T16:53:45","modified_gmt":"2018-05-02T16:53:45","slug":"icelandic-er-haegt-ad-klona-apa","status":"publish","type":"post","link":"https:\/\/uni.hi.is\/apalsson\/IS\/2018\/05\/02\/icelandic-er-haegt-ad-klona-apa\/","title":{"rendered":"Er h\u00e6gt a\u00f0 kl\u00f3na apa?"},"content":{"rendered":"

N\u00e1tt\u00farleg kl\u00f3nun er vel \u00feekkt,til d\u00e6mis vi\u00f0 knappskot e\u00f0a \u00feegar n\u00fd tr\u00e9 vaxa upp af brotnum greinum e\u00f0a f\u00f6llnu tr\u00e9 (samanber stiklinga). \u00cd marga \u00e1ratugi hafa v\u00edsindamenn unni\u00f0 a\u00f0 \u00fev\u00ed a\u00f0 kl\u00f3na d\u00fdr \u00e1 tilraunastofum. Breski l\u00edffr\u00e6\u00f0ingurinn John Gurdon (f. 1933) var fyrstur til a\u00f0 kl\u00f3na hryggd\u00fdr<\/a> \u00feegar hann kl\u00f3na\u00f0i froska<\/a> upp \u00far mi\u00f0ri s\u00ed\u00f0ustu \u00f6ld. Hann f\u00e9kk N\u00f3belsver\u00f0launin \u00ed l\u00edfe\u00f0lis- og l\u00e6knisfr\u00e6\u00f0i \u00e1ri\u00f0 2012<\/a> fyrir ranns\u00f3knir s\u00ednar. Margir kannast vi\u00f0 kindina Doll\u00fd sem v\u00edsindamenn vi\u00f0 Roslin-ranns\u00f3knast\u00f6\u00f0ina \u00ed Skotlandi kl\u00f3nu\u00f0u 1996. Doll\u00fd og nafnlausu froskarnir hans John Gurdons voru b\u00fanir til me\u00f0 a\u00f0fer\u00f0 sem byggir \u00e1 \u00fev\u00ed a\u00f0 fjarl\u00e6gja kjarna \u00far eggi og hvata samruna l\u00edkamsfrumu vi\u00f0 eggi\u00f0 (e. somatic cell nuclear transfer, skammstafa\u00f0 SCNT, bein \u00fe\u00fd\u00f0ing v\u00e6ri ef til vill l\u00edkamsfrumukjarnaflutningur). \u00cd tilfelli Doll\u00fdjar var nota\u00f0ur kjarni \u00far j\u00fagurfrumu kindar af Finn Dorset-kyni en egg \u00far kind af Scottish Blackface-kyni. Me\u00f0 \u00fev\u00ed a\u00f0 nota sitt hvort fj\u00e1rkyni\u00f0 var au\u00f0velt a\u00f0 greina uppruna afkv\u00e6misins vi\u00f0 f\u00e6\u00f0ingu \u00fat fr\u00e1 \u00fatliti, en uppruni kjarna Doll\u00fdar var einnig sta\u00f0festur me\u00f0 sameindaerf\u00f0afr\u00e6\u00f0i.<\/p>\n

Arnar P\u00e1lsson. \u201eEr h\u00e6gt a\u00f0 kl\u00f3na apa?\u201c V\u00edsindavefurinn<\/i>, 9. apr\u00edl 2018. http:\/\/visindavefur.is\/svar.php?id=75518<\/a><\/p>\n

Einr\u00e6ktun af \u00feessu tagi er ekki skilvirk a\u00f0fer\u00f0. Af 277 eggjum sem fengu kjarna \u00far j\u00fagurfrumu komust 29 \u00f3hult \u00ed gegnum fyrstu frumuskiptingarnar og g\u00e1tu mynda\u00f0 k\u00edmbl\u00f6\u00f0ru. Af 29 k\u00edmbl\u00f6\u00f0rum sem voru fluttar \u00ed leg Scottish Blackface-kinda n\u00e1\u00f0u 13 a\u00f0 bindast legveggnum. A\u00f0eins eitt f\u00f3stur gat af s\u00e9r lifandi lamb (6LL3) sem f\u00e9kk nafni\u00f0 Doll\u00fd. \u00deegar Doll\u00fd var kynnt \u00e1ri\u00f0 1997 h\u00e9ldu sumir a\u00f0 h\u00e6gt v\u00e6ri a\u00f0 kl\u00f3na allar l\u00edfverur. S\u00ed\u00f0an hafa 23 tegundir d\u00fdra hafa veri\u00f0 kl\u00f3na\u00f0ar, til d\u00e6mis sv\u00edn, k\u00fdr, kindur, kettir og hundar. Fram til \u00e1rsins 2017 haf\u00f0i engum tekist a\u00f0 kl\u00f3na apa \u00fer\u00e1tt fyrir margv\u00edslegar tilraunir. Stofnfrumus\u00e9rfr\u00e6\u00f0ingurinn Shoukhrat Mitalipov og f\u00e9lagar hans vi\u00f0 Heilsu- og v\u00edsindah\u00e1sk\u00f3lann \u00ed Oregon ger\u00f0 til d\u00e6mis tilraunir me\u00f0 15.000 egg \u00far \u00f6pum en \u00e1n \u00e1rangurs. \u00d3kleifi \u00fer\u00f6skuldurinn vir\u00f0ist hafa veri\u00f0 m\u00f6rkun kjarnanna. M\u00f6rkun \u00e1 s\u00e9r sta\u00f0 \u00ed \u00feroskaferli frumna \u00feegar \u00fe\u00e6r \u00feroskast \u00e1 \u00e1kve\u00f0na braut, til d\u00e6mis \u00ed forvera taugakerfis e\u00f0a h\u00fa\u00f0ar. Frumurnar s\u00e9rh\u00e6fast s\u00ed\u00f0an til d\u00e6mis \u00ed \u00f3l\u00edkar frumur h\u00fa\u00f0ar e\u00f0a heilans. Kjarnar starfa \u00f3l\u00edkt \u00ed m\u00f6rku\u00f0um e\u00f0a s\u00e9rh\u00e6f\u00f0um frumum og frj\u00f3vga\u00f0ri eggfrumu.<\/p>\n

\n
\u00a0Allar frumur l\u00edkamans hafa sama erf\u00f0aefni. Munurinn \u00e1 frumuger\u00f0um er s\u00e1 a\u00f0 \u00fe\u00e6r nota mismunandi gen<\/a>. \u00deetta er best \u00fatsk\u00fdrt me\u00f0 \u00edmyndu\u00f0u d\u00e6mi, segjum til d\u00e6mis a\u00f0 taugafrumur noti 10.000 gen og lifrarfrumur 8.000, en bara 5.000 \u00feeirra eru sameiginleg. Virkni genanna er st\u00fdrt af n\u00e1kv\u00e6mum kerfum, framlei\u00f0sla tiltekinna pr\u00f3t\u00edna er skr\u00fafu\u00f0 upp e\u00f0a ni\u00f0ur eftir a\u00f0st\u00e6\u00f0um og \u00feegar \u00feroskun vindur fram. St\u00fdringin felst me\u00f0al annars \u00ed \u00fev\u00ed a\u00f0 pakka e\u00f0a afpakka tilteknum sv\u00e6\u00f0um \u00e1 litningum sem gerir frumum kleift a\u00f0 muna. \u00c1kve\u00f0in litningasv\u00e6\u00f0i fruma \u00ed h\u00fa\u00f0 eru p\u00f6kku\u00f0 og allar frumur sem af \u00feeim koma einnig. \u00deannig muna \u00fe\u00e6r a\u00f0 \u00fe\u00e6r eru h\u00fa\u00f0 og framlei\u00f0a r\u00e9tt pr\u00f3t\u00edn en ekki til d\u00e6mis meltingarens\u00edm e\u00f0a taugabo\u00f0efni. \u00c1rangurinn \u00ed kl\u00f3nun veltur \u00e1 \u00fev\u00ed hversu vel gengur a\u00f0 endurstilla kjarna gjafafrumunnar. Tilraunir til a\u00f0 kl\u00f3na apa hafa mistekist og \u00fe\u00e1 er spurningin hvort \u00fea\u00f0 s\u00e9 vegna \u00feess a\u00f0 a\u00f0fer\u00f0ir okkar eru \u00f3fullkomnar e\u00f0a vegna \u00feess a\u00f0 kl\u00f3nun virkar ekki fyrir \u00feennan h\u00f3p d\u00fdra sem vi\u00f0 tilheyrum einnig. \u00cd jan\u00faar 2018 birtist grein \u00ed v\u00edsindat\u00edmaritinu Cell<\/cite> eftir Qiang Sun og samstarfsmenn hans vi\u00f0 Taugal\u00edffr\u00e6\u00f0istofnunina \u00ed Shanghai sem s\u00fdndi hvernig h\u00e6gt er a\u00f0 kl\u00f3na makak\u00ed-sm\u00e1apa me\u00f0 kjarnaflutningsa\u00f0fer\u00f0inni. Sun og f\u00e9lagar komust fyrir hindranir sem reyndust \u00f3yfirst\u00edganlegar fyrir alla a\u00f0ra. N\u00fdjungarnar voru tvennskonar. \u00cd fyrsta lagi a\u00f0 nota tiltekin efni og RNA<\/a>-bo\u00f0 til a\u00f0 endurforrita erf\u00f0aefni frumunnar. Um var a\u00f0 r\u00e6\u00f0a efni sem hafa \u00e1hrif \u00e1 litni\u00f0 og mRNA fyrir ens\u00edm<\/a> sem breytir a\u00f0gengi a\u00f0 erf\u00f0aefninu. \u00cd \u00f6\u00f0ru lagi notu\u00f0u \u00feeir f\u00f3sturfrumur \u00far \u00f6punum en ekki frumur \u00far fullor\u00f0num d\u00fdrum e\u00f0a ungvi\u00f0i. Doll\u00fd var til d\u00e6mis kl\u00f3nu\u00f0 \u00far frumum \u00far j\u00fagri fullor\u00f0ins d\u00fdrs, m\u00f6gulega stofnfrumu. F\u00f3sturfrumur er m\u00e1ttugri en venjulegar frumur. H\u00fa\u00f0fruma getur bara af s\u00e9r h\u00fa\u00f0frumur, ekki heilan l\u00edkama. \u00deetta seinna atri\u00f0i \u00fe\u00fd\u00f0ir a\u00f0 kl\u00f3nun fullor\u00f0ins apa hefur ekki tekist heldur a\u00f0eins kl\u00f3nun \u00e1 f\u00f3stri.<\/div>\n<\/div>\n

\u00cd tilrauninni var unni\u00f0 me\u00f0 r\u00famlega hundra\u00f0 egg sem kjarnar h\u00f6f\u00f0u veri\u00f0 fjarl\u00e6g\u00f0ir \u00far. Kjarnalaus egg voru l\u00e1tin renna saman vi\u00f0 stakar \u00feekjufrumur \u00far f\u00f3stri sem gaf 109 k\u00edmbl\u00f6\u00f0rur (f\u00f3stur me\u00f0 um 200-300 frumur). E\u00f0lilegur frumuklasi fannst \u00ed 79 k\u00edmbla\u00f0ranna og voru \u00feau f\u00f3stur sett i sta\u00f0g\u00f6ngum\u00e6\u00f0ur (21 talsins). A\u00f0eins sex f\u00f3stur leiddu til e\u00f0lilegrar me\u00f0g\u00f6ngu og einungis tveir apar (Hua Hua og Zhong Zhong) f\u00e6ddust. \u00deeir komu \u00ed heiminn eftir 135 og 137 daga sem er e\u00f0lileg me\u00f0ganga fyrir makak\u00ed-sm\u00e1apana. Kl\u00f3nun \u00far frumum fullor\u00f0ins apa t\u00f3kst n\u00e6stum. Sun og f\u00e9lagar reyndu einnig a\u00f0 nota l\u00edkamsfrumur fullor\u00f0ins apa, \u00far \u00feekjufrumum eggb\u00fas. Svipa\u00f0ur fj\u00f6ldi eggja var nota\u00f0ur og \u00e1rangurinn samb\u00e6rilegur vi\u00f0 hina tilraunina. Tveir apar gengu fulla me\u00f0g\u00f6ngu og f\u00e6ddust lifandi, en d\u00f3u b\u00e1\u00f0ir innan tveggja daga. \u00c1\u00f0ur h\u00f6f\u00f0u sl\u00edk f\u00f3stur komist 2\/3 me\u00f0g\u00f6ngunnar, a\u00f0 80 degi um \u00fea\u00f0 bil. Hvers vegna voru \u00feessar tilraunir ger\u00f0ar? \u00cd kj\u00f6lfar kl\u00f3nunar Doll\u00fdjar var umr\u00e6\u00f0a um hvort e\u00f0lilegt v\u00e6ri a\u00f0 nota kl\u00f3nun til a\u00f0 fj\u00f6lga f\u00f3lki (e. reproductive cloning). \u00cd flestum vestr\u00e6num r\u00edkjum var sl\u00edk kl\u00f3nun b\u00f6nnu\u00f0 me\u00f0 l\u00f6gum e\u00f0a regluger\u00f0um. Engu a\u00f0 s\u00ed\u00f0ur er n\u00fa r\u00e6tt hvort r\u00e9ttl\u00e6tanlegt s\u00e9 a\u00f0 nota kl\u00f3nun til a\u00f0 l\u00e6kna sj\u00fakd\u00f3ma, til d\u00e6mis lei\u00f0r\u00e9tta erf\u00f0agalla \u00ed f\u00f3stri e\u00f0a afkv\u00e6mi pars. Sl\u00edkt vir\u00f0ist ekki vaka fyrir ranns\u00f3knarh\u00f3p Sun og f\u00e9laga \u00ed Shanghai. Yfirl\u00fdst markmi\u00f0 tilraunanna er a\u00f0 \u00fatb\u00faa l\u00edkan fyrir l\u00edffr\u00e6\u00f0i taugasj\u00fakd\u00f3ma eins og Alzheimer<\/a> og Parkinson<\/a>, sem ekki er h\u00e6gt a\u00f0 herma eftir \u00ed m\u00fasum. \u00deeir vilja nota kl\u00f3nun til a\u00f0 geta bori\u00f0 saman apa me\u00f0 og \u00e1n alvarlegra st\u00f6kkbreytinga<\/a> til d\u00e6mis sem orsaka Alzheimer. Ef tveir apar eru n\u00e1kv\u00e6mlega eins erf\u00f0afr\u00e6\u00f0ilega, nema hva\u00f0 annar er me\u00f0 galla\u00f0 gen, v\u00e6ri m\u00f6gulega au\u00f0veldara a\u00f0 rannsaka l\u00edffr\u00e6\u00f0i sj\u00fakd\u00f3msins. Annmarkar \u00e1 ranns\u00f3knar\u00e1\u00e6tlun \u00feeirra eru l\u00edtil s\u00fdnast\u00e6r\u00f0 og m\u00f6gulega \u00e1hrif erf\u00f0aumhverfis. Einnig er m\u00f6gulegt a\u00f0 kl\u00f3nunin sj\u00e1lf hafi aukaverkanir. S\u00fdnast\u00e6r\u00f0 er mikilv\u00e6g \u00ed v\u00edsindum. Samanbur\u00f0ur \u00e1 tveimur d\u00fdrum er \u00f3fulln\u00e6gjandi, krafa er um st\u00f3r \u00fe\u00fd\u00f0i og a\u00f0 h\u00e6gt s\u00e9 a\u00f0 endurtaka ranns\u00f3knina. \u00dea\u00f0 \u00feyrfti mikinn fj\u00f6lda apynja til a\u00f0 gefa eggin og ganga me\u00f0 f\u00f3strin og s\u00ed\u00f0an heila heimavist sem aparnir \u00feyrftu a\u00f0 b\u00faa \u00ed. Jafnvel \u00fe\u00f3tt b\u00fain ver\u00f0i til nokkur p\u00f6r af \u00f6pum, me\u00f0 e\u00f0a \u00e1n tiltekinnar st\u00f6kkbreytingar, \u00fe\u00e1 \u00feroskast hver \u00feeirra \u00e1 sinn h\u00e1tt og alls \u00f3v\u00edst a\u00f0 h\u00e6gt s\u00e9 a\u00f0 \u00fatb\u00faa \u00feeim n\u00e6gilega svipa\u00f0 umhverfi. Anna\u00f0 vandam\u00e1l er a\u00f0 st\u00f6kkbreytingin sem rannsaka \u00e1 getur haft framandi \u00e1hrif \u00ed apanum, \u00fea\u00f0 er a\u00f0 segja \u00ed erf\u00f0aumhverfi tegundarinnar e\u00f0a jafnvel einstaklingi sem h\u00fan var sett \u00ed. Rhesusapar, \u00e6ttingjar makak\u00edsm\u00e1apanna, eru til d\u00e6mis me\u00f0 \u00fatg\u00e1fur gena sem valda sj\u00fakd\u00f3mum \u00ed manninum en rhesusaparnir s\u00fdna engin einkenni sj\u00fakd\u00f3msins \u00fe\u00f3tt \u00feeir s\u00e9u allir \u201est\u00f6kkbreyttir\u201c. \u00c1st\u00e6\u00f0an er s\u00fa a\u00f0 samhengi st\u00f6kkbreytinga skiptir m\u00e1li, b\u00e6\u00f0i erf\u00f0afr\u00e6\u00f0ilegt samhengi og einnig umhverfislegt, sem er l\u00edka f\u00e9lagsumhverfi. Allt \u00feetta \u00e1 vi\u00f0 um erf\u00f0asj\u00fakd\u00f3ma mannsins eins og sl\u00edmseigjusj\u00fakd\u00f3m<\/a> (Cystic fibrosis), krabbamein og Alzheimer. Almenn gagnr\u00fdni er a\u00f0 l\u00edfverur sem myndast me\u00f0 kl\u00f3nun eru erf\u00f0afr\u00e6\u00f0ilega eldri en venjulegar l\u00edfverur. Kl\u00f3nun byggir \u00e1 a\u00f0 \u201eeldri\u201c frumur s\u00e9 nota\u00f0ar \u00ed n\u00e6stu kynsl\u00f3\u00f0. L\u00edkamsfrumur skipta s\u00e9r oftar en stofnfrumur<\/a> kynfruma. \u00cd hverri skiptingu eru l\u00edkur \u00e1 st\u00f6kkbreytingum og me\u00f0 fleiri skiptingum aukast l\u00edkurnar, samanber krabbamein. Fruma \u00far j\u00fagri \u201ekl\u00f3nm\u00f3\u00f0ur\u201c Doll\u00fdjar var kannski b\u00fain a\u00f0 skipta s\u00e9r 20 sinnum en kynfrumur eins og egg mun sjaldnar. \u00dear af lei\u00f0andi er h\u00e6tta \u00e1 a\u00f0 kl\u00f3nar ver\u00f0i erf\u00f0afr\u00e6\u00f0ilega gamlir. \u00dea\u00f0 felst m\u00f3ts\u00f6gn \u00ed \u00fev\u00ed a\u00f0 kl\u00f3na erf\u00f0afr\u00e6\u00f0ilega fullkomnar verur me\u00f0 a\u00f0fer\u00f0 sem tryggir a\u00f0 \u00fe\u00e6r ver\u00f0i \u00f3fullkomnar. Fr\u00e1 v\u00edsindalegu sj\u00f3narmi\u00f0i er samt forvitnilegt a\u00f0 rannsaka mynstur st\u00f6kkbreytinga \u00ed kl\u00f3nu\u00f0um l\u00edfverum, til d\u00e6mis a\u00f0 kanna hvort l\u00edkur \u00e1 krabbameinum aukist. Einnig er forvitnilegt a\u00f0 rannsaka endurforritun kjarnanna, hversu vel h\u00fan tekst og hvort a\u00f0 fr\u00e1vikin hafi \u00e1hrif \u00e1 \u00f3l\u00edka vefi e\u00f0a l\u00edff\u00e6rakerfi.<\/p>\n

Samantekt<\/strong><\/p>\n