Zofuzo zinxulunyaniswa notshintsho kumanani kunye nesakhiwo zofuzo

Imele ukuba ukuzalwa komntwana - elona xesha lifanelekileyo kubazali, kodwa ke ezimbi. Abaninzi uxhalabile ukuba usana ukuze kuzalwa naziphi abakhubazekileyo, ngokwasemzimbeni okanye abakhubazeke ngengqondo.

Inzululwazi ningemi, kunokwenzeka ukuba ahlole ku mntwana ukukhulelwa ubukho ezingaqhelekanga kuphuhliso. Phantse zonke ezi mvavanyo nga ukubonisa ukuba zonke ok kunye nomntwana.

Kutheni na ukuba abazali inye azalwe abantwana ezahlukeneyo ngokupheleleyo - umntwana okunempilo umntwana onesiphene? It ukuchaza zofuzo. Ekuzalweni baby ubuntwana, okanye umntwana ukhubazekile emzimbeni echaphazela yemfuza gene ezinxulumene utshintsho kwisakhiwo DNA. Siza kuthetha okungakumbi ngale nto. Makhe sibone indlela kusenzeka oku, ezinye izakhi iigene na, kunye noonobangela bazo.

Yintoni kuguquka?

Ngokuguqula imizila - utshintsho iiseli nokomzimba nezamachiza kubume DNA. Isizathu inokuba exposure (ngexesha lokukhulelwa awukwazi ukuthatha imifanekiso X-ray, yomenzakalo kunye kwizaphuko), yelanga eyingozi (exposure ilanga elide ngethuba lokukhulelwa, okanye ukuba kwigumbi izibane yiultraviolet zifakiwe). Kwakhona, le mizila kudluliswe kwaye ilifa ookhokho bethu. Bonke bephela zohlulwa ngokwendidi.

Zofuzo notshintsho kubume chromosome okanye inani

Chromosomal guquko - kuguquka apho isakhiwo kunye nenani zofuzo zatshintsha. imimandla Chromosomal unokuwa okanye kabini, bafudukela kummandla nonhomologous, babuye umva, baphume iqhelekile izidanga elikhulu elinamanci asibhozo.

Ubangelwa kuguquka enjalo - ephula phantsi krossengovere.

Zofuzo zinxulunyaniswa notshintsho kubume chromosome okanye ubungakanani yabo, unobangela izifo kunye nezifo usana. Ezi zifo akanakunyangwa.

Types of chromosome zofuzo

ezimbini kuphela izakhi chromosomal azifani: lwamanani beemeko. Aneuploidy - linani iintlobo zofuzo, oko kukuthi, xa zofuzo zinxulunyaniswa notshintsho inani zofuzo. Yeyona ukuvela ngakumbi nangakumbi ke yokugqibela, ukulahlekelwa nayiphi na kuzo.

Zofuzo ezinxulumene notshintsho kubume kwimeko apho ikhefu chromosome, kwakhona emva koko, waphula uqwalaselo yesiqhelo.

Types of chromosome wokwamanani

Xa inani yemfuza isabelo chromosome aneuploidy, okt iintlobo. Cinga engundoqo, ukufumana umahluko.

• trisomy

Trisomy - is ukuvela kwi karyotype of an chromosome elongezelelweyo. Isenzeko oluqhelekileyo - na ukuvela le chromosome yamashumi amabini ananye. Iba unobangela Down syndrome, okanye, njengoko balibiza izifo - trisomy le chromosome yamashumi amabini ananye.

Patau Syndrome ibanjiwe yi weshumi elinesibhozo kwi chromosome bene Edwards syndrome. Kuxhomekeke trisomy autosomal. Ezinye trisomies kuzo azinakuphila, ukuba ndingafeli embilinini, kwaye kulahleka xa isisu kulogo. Abo bantu baye zofuzo ezongezelelweyo ngesondo (X, Y), - ezinzileyo. Nokubonakaliswa kwezonyango kwezo kwezo liphantsi kakhulu.

izakhi Gene ezinxulumene notshintsho kumanani kwenzeka ngenxa yezizathu ezithile. Trisomy inokufane kwenzeka xa divergence ye zofuzo homologous kwi anaphase (meiosis 1). Isiphumo sale divergence kukuba zombini zofuzo kuwa kuphela elinye iiseli ezimbini intombi, kwaye eyesibini ayinanto.

Ngokuqhelekileyo, kusenokuba non-disjunction zofuzo. Le nto ibizwa ngokuba yaphula ukungangqinelani phakathi chromatids udade. Senzeka meiosis 2. Oku kunjalo xa zofuzo ezimbini ncam bezinzile gamete mnye, ebangela elilodwa trisomic. Nondisjunction livela kwi zigaba yokuqala inkqubo iqanda atsho ukuba sele ivundiswe. Ngaloo ndlela, a iiseli njengesi clone leyo kukugubungela inxalenye enkulu okanye ezincinane le kwithishyu. Maxa wambi kuziveza ngokwezonyango.

Uninzi chromosome amabini ananye linxulunyaniswa ubudala umfazi omithiyo, kodwa le into de namhla akukho bungqina ecacileyo. Izizathu diverge chromosome, azaziwa.

• monosomy

Monosomy ebizwa ukungabikho nayiphi na autosomes. Ukuba oku kuyenzeka, ngoko kwiimeko ezininzi akunakwenzeka ukuba ukuthwala isiqhamo, nokubeleka ngaphambi kwenzeka usaqala. Ngaphandle - monosomy ngenxa chromosome yamashumi amabini ananye. Isizathu sokuba kukho monosomy nibe non-disjunction zofuzo, kunye nelahleko zofuzo ngexesha anaphase indlela yakhe eya ehokweni.

Ngu monosomy zofuzo ngesondo iziphumo olungekazalwa apho XO karyotype. kubonakaliswa kwezonyango karyotype - Turner syndrome. Asibhozo ekhulwini amatyala ngaphandle monosomy ikhulu imbonakalo X chromosome kungenxa lunyhasho meiosis baby daddy. Oku kungenxa nondisjunction X kunye Y zofuzo. Ngokusisiseko, isiqhamo karyotype XO ubulawa nokumithwa.

Ngokutsho zofuzo sex trisomy into zohlulwa ngokwendidi ezintathu: 47 XXY, XXX 47, 47 XYY. Klinefelter kaThixo syndrome yi trisomy 47 XXY. Ekubeni onjalo ithuba karyotype ukuthwala umntwana elahluleleneyo amahlanu-amahlanu. Unobangela wale syndrome inokuba nondisjunction of chromosome X, okanye X kunye Y nondisjunction spermatogenesis. Le karyotypes sesibini nesesithathu lunokwenzeka kuphela elinye amawaka abafazi abakhulelweyo, ukuba phantse kungenzeki kwiimeko ezininzi, iingcali bafumana ngengozi.

• polyploidy

Le zofuzo ezinxulumene utshintsho iseti haploid zofuzo. Ezi khithi kube kathathu kane. Triploids ziye kakhulu ngokuqhelekileyo ukuxilongwa kuphela xa kukho isisu ezikhululekileyo. Kukho iimeko ezahlukeneyo apho unina likwazile ukwenza umntwana onjalo, kodwa bonke bafa phambi yobudala kunye nenyanga. Izakhi zofuzo xa triplodii kunokubangela nokusasazeka okupheleleyo nondisjunction iiseti chromosome nokuba iiseli yintsholongwane obhinqileyo okanye oyindoda. Kwakhona, indlela zinokunika kwezichumiso kabini beqanda. Kulo mzekelo, kukho ubani angakwazi ngumkhaya. Le savuka kuthiwa ukukhulelwa izinyo. Ngokuqhelekileyo, ezi nguqu zikhokelela kuphuhliso ukuphazamiseka zosana kwengqondo kunye nokomzimba, ukuqhomfa.

Yeyiphi imizila gene zinxulunyaniswa notshintsho kubume chromosome

Iinguqu zezakhiwo isiphumo lekhefu chromosomal (ngokwaphulwa) chromosome. Ngenxa yezi zofuzo abaqhagamshelwe, ngokwaphula imbonakalo yakhe yangaphambili. Ezi nguqu ukuze ingafanelekanga efezekileyo. Balanced akukho surplus okanye ukunqongophala eziphathekayo, ke aziveli. Bayakwazi kwenzeka kuphela kwiimeko apho on-site ukutshatyalaliswa chromosome yaba isakhi ukuba kubalulekile ezisebenza. Xa iseti ukulungelelana gametes kungavela ingafanelekanga. Ngenxa yale neqanda gamete kungabangela ukubonakala umbungu, kunye chromosome iseti ingafanelekanga. Ngesi iseti ingane kuphakamisa inani malformations kuvela ezimbi kakhulu.

Iintlobo zokuguqulwa zezakhiwo

Gene ukuziguqula kwenzeka kwinqanaba gamete Ukwakheka. Ukunqanda le nkqubo akakwazi, akukho nto ngokuqinisekileyo uyazi ukuba ezo kwiDNA esinokubakho. Izilungiso zezakhiwo kufuneka iintlobo eziliqela.

• ezicinyiweyo

Olu tshintsho kungenxa ilahleko yinxalenye chromosome. Xa lo msantsa kuba chromosome elifutshane, yaye inxalenye yayo ndanahlula ithe yalahleka enye kwicandelo iseli. ezicinyiweyo Embi - oku ityala xa omnye chromosome yaphukile kwiindawo ezininzi. Ezi zofuzo kuvame ukuvelisa engekazalwa nonviable. Kodwa ke kukho iimeko apho abantwana baye basinda, kodwa ngenxa yale iseti zofuzo yaba Wolf-Hirschhorn syndrome, "ukukhala ikati yakhe."

• ukuphindaphindeka

Ezi ukuguquka gene kwenzeka kwinqanaba nokucwangciswa DNA kabini. Ngokomthetho phindwa ayikwazi ukuba unobangela ezingaqhelekanga ezifana ezibangela cimo.

• kwazo

Ukufuduselwa kwenzeka ngenxa ukudluliselwa izinto yemfuza ukusuka chromosome omnye komnye. Ukuba kukho uqhekeko kwi zofuzo eziliqela kwaye ukutshintsha amacandelo, umcimbi uba unobangela retsiproktnoy kwazo. Le karyotype yale kwazo iye zofuzo mane anesithandathu nje kuphela. Le kwazo efanayo kanye kuphela yi ucazululo olunzulu kunye nofundo zofuzo.

Utshintsho ngokulandelelana nucleotide

Zofuzo zinxulunyaniswa notshintsho ngokulandelelana nucleotide, xa zibalulwe loyamano isakhiwo amanye amacandelo DNA. Xa neziphumo zofuzo ezinjalo zohlulwa ngokwendidi ezimbini - ngaphandle kokuba shift isakhelo kunye shift. Bazi ukuba yintoni ebangela abacombululi DNA, kuyafuneka ukuba siqwalasele uhlobo ngalunye ngokwahlukeneyo.

Isakhelo shift ukuguquka, ngaphandle

Ezi ukuguquka gene zinxulunyaniswa notshintsho kunye nokutshintshwa ngababini kwisiseko kubume DNA. Ukuba esikhundleni ezinjalo singalahlekani ubude DNA, kodwa unako kulahleka kwaye ukutshintshwa asidi acid. Kukho kungenzeka ukuba isakhiwo kwiproteni igcinwa, iya kusebenza degeneracy ikhowudi yezofuzo. Cinga iinkcukacha zombini iinketho: obekulahlekile ngaphandle kwabadlali acid acid.

Ngokuguqula imizila ngokuvuselela acid

Ukutshintsha i amasalela acid acid kwi polypeptide ekuthiwa zofuzo missense. In kwemolekyuli haemoglobin kukho ezine neentsontelo zabantu - ezimbini "kunye" (oko ise-chromosome elinesithandathu), kunye ababini "b" (ikhowudi kwi chromosome elinanye). Ukuba "b" - uluhlu oluqhelekileyo, kwaye kukho i elinamanci mane yesithandathu iintsalela acid acid kubume bayo, kwaye yesithandathu kukho glutamic, athwala kuyinto eqhelekileyo. Kulo mzekelo, i glutamic acid ukuba enkhowudwa GAA triplet. Ukuba ngenxa yemfuza GAA gta indawo, kunokuba glutamic acid kwi Isibomvisi valine kwakhiwa. Ngaloo ndlela, endaweni yetekisi oluqhelekileyo HbA ubonakala omnye athwala HbS. Ngenxa yoko, kufakwe omnye acid acid, kwaye nucleotide olunye iya kubangela izifo ezimbi kakhulu - irhengqa cell anemia.

Isifo kuboniswa into yokuba iiseli ezibomvu igazi ukuba zimile njenge irhengqa. Ngenxa yoko, ukuba nako ukubahlangula kakuhle ioksijini. Ukuba kwinqanaba cellular ezi homozygous HbS / HbS ifomula, oko kukhokelela ukufa umntwana kwabaNtwana abasaKhulayo. Ukuba ifomula HbA / HbS, iiseli ezibomvu azinayo ifomu buthathaka yokutshintsha. Olu tshintsho kancinane luphawu luncedo - ukuxhathisa seengcongconi. Kuloo mazwe apho kukho ingozi izivumelwano imalariya ziyafana ebanda eSiberia, olu tshintsho has a luncedo.

Ngokuguqula imizila ye asidi acid ngaphandle replacement

esikhundleni Nucleotide ngaphandle exchange acid ekuthiwa seymsens zofuzo. Ukuba ummandla DNA usebenzisa ikhowudi kwi "b" - wesekethe uya kutshintshwa kwindawo GAA gag, koko ngenxa yokuba ikhowudi yezofuzo iya kuba bangaphezu kwemfuneko, abangamalalela acid glutamic ngeke kwenzeke. isakhiwo chain akawatshintshi loo manqaku, i erythrocytes akayi kuba nokulungalungiswa.

kwezakhi Frameshift

Ezi ukuguquka gene zinxulunyaniswa notshintsho ngobude DNA. Ubude inokuba lincinane okanye ngaphezulu, kuxhomekeke ilahleko okanye ukongeza izibini nucleotide. Ngaloo ndlela, isakhiwo yonke ngokupheleleyo kwiproteni kutshintshwe.

ingcinezelo Intragenic kungenzeka. Oku kwenzeka xa kukho indawo kwezo ezimbini oluhlawula omnye. Eli lixesha wokujoyina ngababini nucleotide emva umntu sele yalahleka, yaye vice versa.

Suka zofuzo

Le iqela elikhethekileyo izakhi. Inqabile, kwimeko yakhe, apho ukuvela codons stop. Oku kwenzeka zombini kwi ukulahleka ngezibini isiseko, kwaye eqale zabo. Xa kukho codons stop, le polypeptides kuyondelelaniswe iyeka ngokupheleleyo. Ngoko unako ukwenza allele null. Ayizi uzakuthelekisa naziphi omnye iiprothini.

Kukho ikho into ingcinezelo intergenic. Le yinkolelo apho ukuguquka sofuzo omnye ayisayicinezeli i imizila kwezinye.

ingaba utshintsho zafunyanwa ngethuba lokukhulelwa?

izakhi Gene ezinxulumene iinguqu kwinani zofuzo kwiimeko ezininzi icaciswa. Ukuze ufumanise ukuba Iziphene zokuzalwa kuphuhliso ngezifo, kwiiveki zokuqala zokukhulelwa (ukusuka kwiiveki ezilishumi ukuya nantathu) zokuhlola emiselweyo. Olu luluhlu iisaveyi ezilula: a ucingo kwiisampuli igazi ngomnwe kunye vein ultrasound. On ultrasound Palsy iphathwa ngokungqinelana parameters zonke iziphelo, impumlo kunye nentloko. Ezi iparameters kwindawo non-ukuthotyelwa strong ibonisa ukuba usana iziphene kuphuhliso. Ukuze uqinisekise okanye ukuphika uxilongo esekelwe kwiziphumo zovavanyo kwegazi.

Kwakhona, egadiwe kumagqirha oomama elizayo, iintsana ekusenokwenzeka ukuba kuguquka kwinqanaba yemfuza, into njengelifa. Oko kukuthi, abo bafazi, izalamane kuzo amatyala umntwana abakhubazeke ngengqondo okanye ngokwasemzimbeni, ezichongiweyo Down syndrome, Patau kunye nezinye izifo yemfuza.