Kunzwisisa Kusiyanisa muAlleles
Kana iwe wakanga uri kuverenga pamusoro pemararamiro emuviri, unogona kunge wakawana mazwi "homozygous" kana "heterozygous"? Asi izvi zvinorevei? Uye ndezvipi zvinobudirira zveku "homozygous" kana kuti "heterozygous" kune rimwe gene?
Chii Chinonzi Gene ?
Tisati tatsanangura homozygous uye heterozygous, tinofanira kutanga tifunga nezvemajini. Rimwe nerimwe remasero ako rine marefu akawanda eDNA (deoxyribonucleic acid).
Izvi ndezvokufananidzira izvo iwe unowana kubva kune umwe neumwe wevabereki vako.
DNA inoumbwa nenyaya dzakasiyana-siyana dzinonzi nucleotides. Kune marudzi mana akasiyana-siyana eucleuclea muDNA: adenine (A), guanine (G), cytosine (C), uye thymine (T). Mukati memusero, DNA inowanzowanikwa yakaiswa mumakromosomes (inowanikwa mune mapoka maviri akasiyana).
Zvinyorwa zvikamu zvakanyatsonaka zvikamu zveDNA zvine chinangwa chakasiyana. Izvi zvikamu zvinoshandiswa nemamwe magetsi mukati memusero kuita mapuroteni chaiwo. Mapuroteni ndiwo matombo ekuvakwa anoshandiswa mumabasa akawanda anokosha mukati memuviri, kusanganisira sangano rekusimbisa, kushandiswa kwemasero, kushandiswa kwemakemikari kushandiswa, uye kutakura. Sero rinoita mapuroteni (kunze kwechivako chacho, amino acids) nokuverenga kuwirirana kweiucleotidi inowanika muDNA. Sero rinoshandisa rudzi rweshanduro yekushandisa kushandisa ruzivo muDNA yekuvaka mapuroteni chaiwo ane zvivakwa zvakasiyana nemabasa.
Majini chaiwo mumuviri anozadzisa mabasa akasiyana. Semuenzaniso, hemoglobin ipuroteni yakaoma yakaoma inoshanda kutakura okisijeni muropa. Majini akasiyana-siyana (akawanikwa muDNA) anoshandiswa nesero kuti iite mapuroteni chaiwo anodiwa nokuda kwechinangwa ichi.
Unotora DNA kubva kuvabereki vako.
Kunyanya kutaura, hafu yeDNA yako inobva kuna amai vako, uye imwe hafu kubva kuna baba vako. Kune majini mazhinji, iwe unotora imwe kopi kubva kuna amai vako uye imwe kubva kuna baba vako. (Zvisinei, kune chimwe chinhu chinosanganisira maviri echromosomes anonzi sex chromosomes. Nemhaka yekuti maitiro echromosomes zvebonde anobata sei, varume vanongowana imwe kopi yemamwe majini.)
Kusiyana muGenesis
Iti genetic code yevanhu yakafanana zvakafanana: Zvikamu zvinopfuura 99 kubva muzana zveyucleotide iyo chikamu chemajini zvakafanana kune vanhu vose. Zvisinei, kune zvimwe zvakasiyana-siyana mukuenzanirana kweiucleotides mune mamwe mazita ejeni. Semuenzaniso, kumwe kushandiswa kwegene kunotanga nekuenzanisa A T TGCT, uye imwe shanduko inogona kutanga A C TGCT pane. Izvi zvakasiyana-siyana zvemajini zvinonzi alleles.
Dzimwe nguva kuchinja uku hakuiti misiyano mumapuroteni ekupedzisira, asi dzimwe nguva vanoita. Zvinogona kukonzera musiyano muduku muprotini inoita kuti iite zvishoma zvakasiyana.
Munhu anonzi ari homozygous yejeni kana ane maviri akafanana makopi ejeni. Muchiitiko chedu, izvi zvingadai zviri mapepi maviri ehurukuro yegene kutanga "A T TGCT" kana ma kopi maviri ehurukuro inotangira "A C TGCT." Heterozygous zvinoreva kuti munhu ane shanduko mbiri dzakasiyana dzejeni (rakagarwa nhaka kubva kune mumwe mubereki, uye mumwe kubva kune mumwe mubereki).
Muchiitiko chedu, heterozygote yaizova nehumwe huwandu hwegene hunotangira "A C TGCT" uyewo imwe shanduro yegene inotanga " T TGCT."
Dzease Mutations
Zvakawanda zvezviitiko izvi hazvisi basa guru, uye zvinongobatsira pakusiyana kwevanhu. Zvisinei, zvimwe zviitiko zvakasiyana-siyana zvinogona kutungamirira kune zvirwere zvevanhu. Izvi ndizvo zvinowanzoreva vanhu pavanotaura nezve "homozygous" uye "heterozygous": rudzi rwemhando yakasiyana-siyana inogona kukonzera chirwere.
Imwe muenzaniso ndeyekuresa cell cell anemia . Muchikwereti cheseinemia anemia, kune kuchinja mune imwe nucleotide inokonzera shanduko mu nucleotide yegene (inonzi β-globin gene).
Izvi zvinokonzera shanduko inokosha mukugadzirisa kwehemoglobin. Nemhaka yeizvi, masero matsvuku eropa akatakura hemoglobin anotanga kuputsa asati asvika. Izvi zvinogona kutungamirira kumatambudziko akaita seanemia nekuperevedza kwefema.
Kazhinji kutaura, pane mitatu mitatu yakasiyana:
- Mumwe munhu ane homozygous yezvinodiwa β-globin gene (ine mavara maviri akaenzana)
- Mumwe munhu anonzi heterozygous (ane chimiro chakasvibirira uye imwe isina kukodzera)
- Mumwe munhu ane homozygous nokuda kwechirwere chesab-globin gene (ine makopi maviri asina kukodzera)
Vanhu vane heterozygous yejeni rejeni gene vane imwe maitiro asina kukanganiswa ejeni (kubva kune mumwe mubereki) uye imwe iyo yakagadziriswa yejeni (kubva kune mumwe mubereki). Vanhu ava havanzwisisi zviratidzo zve sickle cell anemia. Zvisinei, vanhu vane homozygous for the abnormal β-globin gene vanowana zviratidzo zve sickle cell anemia.
Unoita Heterozygotes Unogona Kuwana Matachiona Evanhu Here?
Hungu, asi kwete nguva dzose. Izvo zvinoenderana nerudzi rwechirwere. Mune dzimwe mhando dzehutachiona hwehutachiona , munhu anonzi heterozygous anenge ava nechokwadi kuti awane chirwere chacho.
Mune zvirwere zvinokonzerwa nezvinonzi zvinodhaka zvemajeni, munhu anoda kopi imwe chete yakaipa yejeni kuti iine matambudziko. Imwe muenzaniso ndeye chirwere chepfungwa cheHertington's disease . Munhu ane rimwe chete rinokonzerwa nejeni (rakagara nhaka kubva kumubereki mumwe nomumwe) achange achinyatsotora chirwere ichi se heterozygote. (A homozygote uyo anogamuchira mapepa maviri asingazivikanwi echirwere kubva kuvabereki vose aizotaridzirwa, asi izvi hazvisati zvanyanya kufanana nezvirwere zvinowanzoita zvirwere.)
Kunyange zvakadaro, nokuda kwezvirwere zvakanyanya, sairle cell anemia, heterozygotes haigoni kuwana chirwere chacho. (Zvisinei, dzimwe nguva vangave vane dzimwe shanduko dzisinganzwisisiki, zvichienderana nehosha.)
Ko Zvakadini NevaKromosomes Zvepabonde?
Zvepabonde chromosomes ndeye X uye Y chromosomes iyo inobatsira pakuparadzaniswa kwevakadzi. Vakadzi vanogara mbiri X chromosomes, imwe kubva kumubereki mumwe nomumwe. Saka chikadzi chinogona kutorwa se homozygous kana heterozygous pamusoro pechimwe chimiro che X chromosome.
Varume vari kunyanya kuvhiringidza. Vanotora ma chromosomes maviri akasiyana epabonde: X uye Y. Nokuti idzi chromosomes mbiri dzakasiyana, mazwi "homozygous" uye "heterozygous" haashandisi kune aya ma chromosomes maviri kune varume. Iwe unogona kunge wakanzwa nezvirwere zvepabonde, zvakadai seDuchenne muscular dystrophy . Izvi zvinoratidzira nhaka yakasiyana yemuenzaniso pane zvirwere zvakasiyana-siyana zvinotapukira zvakatorwa nedzimwe chromosomes (dzinonzi autosomes).
Heterozygote Kubatsira
Kune dzimwe zvirwere zvemajeri, zvinokwanisika kuti kuva heterozygote kunopa munhu zvimwe zvakanakira. Semuenzaniso, inofungidzirwa kuti kuva heterozygote ye sickle cell anemia gene inogona kunge yakadzivirira marariya, mukuenzanisa kune vanhu vasina kopi isina kukodzera.
Nhaka
Ngatitorei maBhaibheri maviri ejeni: A uye a. Apo vanhu vaviri vane mwana, kune mikana yakawanda:
- Vose vabereki vari AA. Vana vavo vose vachava AA pamwe (homozygous yeAA).
- Vose vabereki vari aa. Ipapo vana vavo vose vachave vakafanana (homozygous for aa).
- Mumwe mubereki ndiye Aa uye mumwe mubereki ndiye Aa. Mwana wavo ane muzana we25 muzana weAA (homozygous), 50 mukana wekuti ave Aa (heterozygous), uye 25 muzana mukana wokuva aa (homozygous)
- Mumwe mubereki ndiye Aa uye imwe ndeye aa. Mwana wavo ane 50 muzana yemukana wokuva Aa (heterozygous) uye 50 muzana mukana wokuva aa (homozygous).
- Mumwe mubereki ndiye Aa uye imwe iAA. Mwana wavo ane 50 muzana yekana yekuva AA (homozygous) uye 50 muzana yekana yekuva Aa (heterozygous).
Shoko Rinobva
Kudzidza kwemajeni kwakaoma. Kana ruzivo rwemagariro runoitika mumhuri yako, usanonoka kubvunza chiremba wako wehutano nezvezvinorevei kwauri.
> Sources:
> Berg JM, Tymoczko JL, Stryer L. Biochemistry. 6 th ed. New York, NY: WH Feedman uye Company; 2007.
> Frenette PS, Atweh GF. Sickle cell disease: kuwanikwa kwekare, pfungwa itsva, uye remangwana chivimbiso. Zvinyorwa zveKliniki Investigation . 2007; 117 (4): 850-858. doi: 10.1172 / JCI30920.
> Nussbaum RL, McInnes RR, Willard HF, Hamosh A. Genetics muMishonga 7 th ed. Philadelphia, PA: Sauders Elsevier; 2007.