Hlola Ubungqina

MASITHI ukwisiqithi esikude nesingenabantu. Njengoko uhamba ngaselunxwemeni ubona ilitye elibhalwe “John 1800.” Ngaba ukungabikho kwabantu kweso siqithi kungakwenza ucinge ukuba lo mbhalo ubekho kuba elo litye belimane libethwa ngumoya namanzi? Akunjalo! Ubuza kube unyanisile xa ugqiba kwelokuba wabhalwa ngumntu othile. Kutheni sisitsho nje? Okokuqala, oonobumba namanani abhalwe ngokucacileyo—enoba abhalwe ngolwimi ongalwaziyo—akasuki nje azivelele. Okwesibini, umbhalo okweli litye uyavakala ukuba uthini, nto leyo ebonisa ukuba kukho umntu onengqondo owawubhalayo.

Kubomi bemihla ngemihla sibona inkcazelo eyahlukahlukeneyo—enye ibhalwe ngeBraille, oonobumba, imifanekiso, iinowuthi zomculo, enye siyiva ithethwa, enye isalathwa ngezandla, enye siyiva kunomathotholo ukanti enye siyifumana kwiinkqubo zekhompyutha. Le nkcazelo idluliselwa ngeendlela ezahlukahlukeneyo, njengamaza omoya okanye iphepha neinki. Enoba idluliselwe njani, abantu basoloko besithi inkcazelo ecacileyo ivela kwingqondo ekrelekrele—ngaphandle kokuba loo nkcazelo ikwiseli. Kaloku abantu abathi ubomi bazivelela, bathi inkcazelo ekwiseli yabakho ngamabonandenzile. Kodwa ngaba kunjalo? Makhe sihlole ubungqina.

Ngaba Inkcazelo Entsonkothileyo Ingasuka Nje Izibhale?

Kumbindi weseli nganye esemzimbeni wakho kukho inkcazelo entsonkothileyo ekuthiwa yideoxyribonucleic acid, i-DNA ngamafutshane. Le nkcazelo ifumaneka kwimolekyuli ende efana neleli ejijekileyo. I-DNA yakho ilawula ukusekwa, ukukhula, ukulondolozwa nokuveliswa kwezigidi ngezigidi zeeseli ezenza umzimba wakho. Ngokuyintloko i-DNA yakhiwa ziinucleotides. Ezi zakhi zibizwa ngokuba zii-A, C, G, okanye T, kuxhomekeke kwichiza elikuzo.a Njengokuba oonobumba bedla ngokusetyenziswa xa kusakhiwa izivakalisi ezahlukahlukeneyo, nazo ezi zakhi zinokudityaniswa ngeendlela ezahlukeneyo ukuze kuveliswe imiyalelo yokwenza ezinye iiseli okanye izinto ezenzeka phakathi kuzo.

Xa iyonke, inkcazelo egcinwa kwi-DNA yakho ibizwa ngokuba yigenome. Enye indlela abalungelelaniswa ngayo oonobumba kwi-DNA kumntu othile iye ingafani neyabanye abantu kuba i-DNA inenkcazelo ephathelele imizila yemfuza—njengombala weliso lakho, ibala lolusu, indlela emile ngayo impumlo yakho, njalo njalo. Ngamafutshane, singathi igenome ifana nethala leencwadi elikhulu eligcine inkcazelo ephathelele indlela elifanele lakhiwe ngayo ilungu ngalinye lomzimba wakho ukuze kuphume wena.

Likhulu kangakanani eli thala? Limalunga neenucleotides eziziibhiliyoni ezintathu ubude. IHuman Genome Project ithi, ukuba ibinokubhalwa phantsi le nkcazelo, ibiya kuzalisa imiqulu engama-200 yeencwadi ezineenombolo zefowuni ezinamaphepha ali-1 000.

Ezi zinto zisikhumbuza umthandazo oxhokonx’ iingcinga owabhalwa kwiminyaka engama-3 000 eyadlulayo. Ufumaneka eBhayibhileni kwiNdumiso 139:16 yaye uthi: “Amehlo akho andibona ndiseyimbumba, yaye zonke iinxalenye zam zazibhalwe phantsi.” Kakade ke, umbhali wala mazwi wayengacingi ngenzululwazi kodwa ngolwimi olulula wasebenzisa umzekelo ochane ngendlela emangalisayo ukuze achaze ubulumko namandla kaThixo angenakuthelekiswa nanto. La mazwi ahluke ngokupheleleyo kweminye imibhalo yeecawa zamandulo eyayizaliswe ziintsomi neenkolelo!

Lenziwa Ngubani Eli “Thala”?

Ukuba sikholelwa ukuba kukho umntu owawabhala elityeni amagama athi “John 1800,” ngaba asifanele sicinge njalo nangenkcazelo entsonkothe nangakumbi nenenjongo ecacileyo efumaneka kwi-DNA? Ngaphezu koko, inkcazelo iyafana nenye kungakhathaliseki ukuba ifumaneka phi yaye idluliselwa njani. Isazinzulu sekhompyutha nenkcazelo uDonald E. Johnson wathi, inkolelo yokuba inkcazelo entsonkothileyo ingazivelela ize isebenze ngendlela emangalisayo ayivumelani nemithetho yezenzululwazi. Yaye licacile elokuba ukuze ukwazi ukubhala inkcazelo entsonkothe kakhulu kufuneka nawe ube ngumntu okrelekrele ngeyona ndlela. Umntwana angakwazi ukubhala amagama athi “John 1800.” Kodwa yingqondo ekrelekrele ngaphezu kweyabantu enokukwazi ukubhala inkcazelo engobomi. Iphephancwadi iNature lithi, ngaphezu koko, okukhona sifunda into entsha “kokukhona sibona indlela obuntsonkothe ngayo ubomi.”

Ukuthi inkcazelo entsonkothileyo efumaneka kwi-DNA yabakho ngamabonandenzile, akukho ngqiqweni yaye kuyaphikisana namava abanawo ngobomi abantu.b Inkolelo enjalo ifuna ukholo olungaphaya koluqhelekileyo.

Kwimigudu yabo yokungqina ukuba akukho Thixo, abantu abathi izinto zazivelela baye ngamaxesha athile bafikelela kwizigqibo eziye zafunyaniswa zibubuxoki kamva. Ngokomzekelo, bathi ama-98 ekhulwini enkcazelo ekwi-DNA yethu yinkunkuma nje engenamsebenzi—efana nethala elineebhiliyoni zamagama angancedi nganto.

Ngaba Ngokwenene Yinkunkuma?

Izazi ngebhayoloji zazikade zisithi awukho omnye umsebenzi we-DNA ngaphandle kokunceda ekuvelisweni kweeprotini. Noko ke, ekuhambeni kwexesha kwaye kwacaca ukuba ziinxalenye zayo ezi-2 ekhulwini kuphela ezincedisa ekuvelisweni kweprotini. Yintoni ke ngoko eyenziwa ngamanye ama-98 ekhulwini e-DNA? UJohn S. Mattick ongunjingalwazi webhayoloji kwiYunivesithi yaseQueensland eBrisbane, eOstreliya uthi, le DNA ekwakungaziwa ukuba yeyokwenza ntoni “kwasuka kwacingwa ukuba yinkunkuma nje engenamsebenzi.”

Isazinzulu ekuthiwa seza negama elithi “i-DNA ‘eyinkunkuma’” nguSusumu Ohno owayesithi izinto zazivelela. Kwiphepha lakhe elalisithi “So Much ‘Junk’ DNA in Our Genome,” wabhala wathi inxalenye eseleyo ye-DNA “iziintsalela zamalinge aphanzileyo endalo. Umhlaba uzele ngamaxhwayela ezinto ezingasekhoyo namhlanje; ngaba ke ngoko thina sifanele simangaliswe kukubona i-DNA yethu izaliswe ziintsalela zemizila yemfuza engasekhoyo?”

Inkolelo yobukho be-DNA “eyinkunkuma” ibe naliphi igalelo kwizifundo zemizila yemfuza? Isazi sebhayoloji uWojciech Makalowski uthi, iimbono ezinjalo “zabangela ukuba abaphandi babe madolw’ anzima ukuphanda ngenxalenye ye-DNA engasetyenziswayo xa kuveliswa iiprotini,” ngaphandle nje kwebathwana lezazinzulu “ezazibek’ esichengeni sokugculelwa ngokuphanda ngalo mbandela untunu-ntunu. Kungenxa yazo le nto uluvo lokuba kukho inxalenye ye-DNA eyinkunkuma . . . lwaqalisa ukutshintsha ebutsheni beminyaka yee-1990.” Uthi, ngoku izazinzulu ziyakubona ukubaluleka koko kwakukade kubizwa ngokuba yinkunkuma.

UMattick uthi, uluvo lwe-DNA eyinkunkuma lungumzekelo obalaseleyo wendlela izazinzulu edla “ngokukuthintela ngayo ukuhlolisiswa kwazo zonke izibakala.” Uthi: “Ukungayiqondi kakuhle indima ephunyezwa yi-DNA kusenokuba yeyona mpazamo inkulu yakhe yenziwa kwibhayoloji.” Kuyacaca ukuba inyaniso engokwenzululwazi ifanele ixhaswe bubungqina, kungekhona izimvo zabantu abaninzi. Sekunjalo, yintoni eboniswa bubungqina bakutshanje ngendima edlalwa yile nxalenye ye-DNA bekukade kucingwa ukuba yinkunkuma?

Oko Kwenziwa Yile “Nkunkuma”

Umzi-mveliso owenza iimoto usebenzisa oomatshini ukuze wenze iinxalenye zemoto. Ezi nxalenye sinokuzifanisa neprotini ekwiseli. Kwakhona, lo mzi-mveliso kufuneka ube nobunye ubuxhakaxhaka bokudibanisa ezi nxalenye zemoto kunye nobunye obulawula oomatshini. Kwenzeka into efanayo nakwizinto ezenzeka ngaphakathi kwiseli. Abaphandi bathi koko kanye okwenziwa yile DNA bekukade kusithiwa awukho umsebenzi wayo. Uninzi lwayo luqulethe imiyalelo yokwenziwa kweemolekyuli ezintsonkothileyo ezibizwa ngokuba yi-RNA (ribonucleic acid), ezidlala indima ephambili ekukhuleni kweseli nasekusebenzeni kwayo.c Kwiphephancwadi iNature, isazi sebhayoloji uJoshua Plotkin uthi: “Ubukho bezi molekyuli bubodwa nje bubonisa indlela . . . oluluncinane ngayo ulwazi lwethu.”

Kwakhona, umzi-mveliso osebenza kakuhle ufanele ube nenkqubo yonxibelelwano esebenza kakuhle. Kwenzeka into efanayo nakwiseli. UTony Pawson, isazi ngeeseli kwiYunivesithi yaseToronto eOntario, uthi: “Unxibelelwano ngaphakathi kwiseli lwenziwa ngeendlela ezininzi ezintsonkothileyo,” nto leyo esenza sibone ukuba yonke le nto “intsonkothe ngakumbi” kunokuba bekucingwa. Kunjengokuba esinye isazi ngemizila yemfuza seYunivesithi yasePrinceton sakha sathi, “asikaziqondi nangoku izinto ezilawula oko kwenzeka ngaphakathi kwiseli kunye nendlela ezisebenzisana ngayo iiseli ezahlukahlukeneyo.”

Nto nganye efundwayo ngeseli ingqina ukuba ilungelelaniswe yaye intsonkothe ngendlela engathethekiyo. Kutheni ke ngoko abantu abaninzi besemi ngelithi ubomi nezona ndlela zokunxibelelana zintsonkothileyo kwezakha zabonwa ngabantu, zabakho ngamabonandenzile?

[Imibhalo esemazantsi]

[Ibhokisi ekwiphepha 5]

INDE KANGAKANANI I-DNA YAKHO?

Xa yoluliwe, i-DNA ekwiseli yomzimba wakho enye imalunga neemitha ezimbini ubude. Ukuba ubunokukhupha i-DNA ekwizigidi ngezigidi zeeseli ezisemzimbeni wakho wonke uze uyidibanise, ubude bayo bebuya kuwuphinda phantse izihlandlo ezingama-670 umgama wokusuka emhlabeni uye elangeni uze uphinde ubuye. Bekuya kukuthatha iiyure ezili-185 ukuhamba loo mgama ngesantya selitha.