Gene maye gurbi suna hade da canje-canje a cikin yawan da tsarin chromosomes

Jiran haihuwar yaro - lokaci mafi kyau ga iyaye, amma kuma mafi mũnin. Mutane da yawa sun damu da cewa baby iya haife tare da wani nakasa, a zahiri ko wata nakasa.

Kimiyya ba tsaya har yanzu, yana yiwuwa ya duba a kan jaririn a ciki ga gaban munanan a ci gaba. Kusan dukkan wadannan gwaje-gwaje iya nuna idan duk ok tare da yaro.

Me ya sa yake cewa wannan iyaye za a iya haife mabanbanta yara - m yaro da kuma wani yaro da tawaya? Yana ƙayyade genes. A haihuwa m baby ko yaro tare da wani nakasar da shafi gene maye gurbi hade da canje-canje a cikin jigidar halittar DNA. Za mu yi magana game da cewa. Bari mu ga yadda wannan ya faru, wasu gene maye gurbi ne, kuma su haddasawa.

Mene ne maye gurbi?

Maye gurbi - wani canji a cikin physiological da nazarin halittu Kwayoyin a DNA tsarin. A dalilin iya zama daukan hotuna (a lokacin daukar ciki ba zai iya daukar hotuna na X-ray, domin raunin da samu karaya), hasken ultraviolet (dogon rana mai daukan hotuna a lokacin daukar ciki, ko zama a cikin dakin da hada ultraviolet fitilu). Har ila yau, wadannan maye gurbi za a iya wuce a kuma gāda daga kakanninta. Dukan su kasu kashi daban.

Gene maye gurbi da canje-canje a chromosome tsarin ko yawan

Chromosomal maye gurbi - maye gurbi a cikin abin da tsarin da kuma yawan chromosomes canza. Chromosomal yankuna iya fada ko biyu, ya koma nonhomologous zone, kunna daga na kullum ga ɗari da tamanin digiri.

A Sanadin irin wannan maye gurbi - wani take hakkin a karkashin krossengovere.

Gene maye gurbi suna hade da wani canji a chromosome tsarin ko da yawa, suna cikin hanyar tsanani cuta da cututtuka a cikin jariri. Wadannan cututtuka su ne m.

Iri chromosome maye gurbi

Kawai iri biyu manyan chromosomal maye gurbi bambanta: lamba da kuma tsarin. Aneuploidy - shi ne yawan iri chromosomes, wato, a lokacin da gene maye gurbi suna hade da wani canji a cikin adadin chromosomes. Shi ne fitowan da kuma da na karshen, da asarar kõwa daga gare su.

Gene maye gurbi hade da canje-canje a tsarin a cikin akwati inda chromosome hutu, kuma baya sake saduwa, da keta al'ada sanyi.

Iri na lamba chromosome

By yawan maye gurbi a kan chromosome aneuploidy rabo, watau jinsin. Ka yi la'akari da main, gano bambanci.

• trisomy

Trisomy - shi ne fitowan a cikin karyotype na karin wani chromosome. A mafi kowa sabon abu - shi ne zargin da ashirin-farko chromosome. Yana zama cikin hanyar Down ciwo, ko, kamar yadda suka kira shi cuta - trisomy na ashirin-farko chromosome.

Patau Syndrome aka gano ta goma sha uku da kuma goma sha takwas a chromosome kamu Edwards ciwo. Yana da dukan autosomal trisomy. Sauran trisomies ba mai yiwuwa, suka mutu a cikin mahaifa, kuma aka rasa a lokacin da maras wata-wata zubar da ciki. Wadanda mutane da ke ƙarin jima'i chromosomes (X, Y), - dorewa. The asibiti bayyanuwar irin maye gurbi ne ragu.

Gene maye gurbi hade da canje-canje a cikin lambobin faruwa ga takamaiman dalilai. Trisomy mafi kusantar su faru a lokacin da bambanta rarrabuwar na chromosomes homologue a anaphase (meiosis 1). A sakamakon wannan bambanta rarrabuwar ne cewa duka chromosomes fada kawai a daya daga cikin biyu ya Kwayoyin, da kuma na biyu shi ne komai.

Kadan fiye, shi yana iya zama ba disjunction na chromosomes. Wannan sabon abu ne da ake kira take hakkin hilafa tsakanin 'yar'uwar chromatids. Yana auku a meiosis 2. Wannan shi ne yanayin a lokacin da biyu m chromosomes shirya a daya gamete, haddasa trisomic zygote. Nondisjunction ya auku a farkon matakai na kwai, kawar da aiwatar da cewa an hadu. Saboda haka, a clone mutant Kwayoyin wanda za a iya rufe wani ya fi girma ko karami ɓangare na nama. Wani lokaci yana bayyana kanta asibiti.

Mutane da yawa daga cikin ashirin-farko chromosome ake dangantawa da shekaru na ciki mace, amma wannan factor har yau yana da babu hujja bayyananniya. Dalilan da ba diverge chromosome, kasance ba a sani ba.

• monosomy

Monosomy kira da rashin wani daga cikin autosomes. Idan wannan ya faru, to, a mafi yawan lokuta ba shi yiwuwa a yi 'ya'yan, wanda bai kai haihuwar faruwa a farkon matakai. Togiya - monosomy saboda da ashirin-farko chromosome. Dalilin da cewa akwai wani monosomy iya zama wadanda ba disjunction na chromosomes, da kuma asarar chromosomes a lokacin anaphase ta hanyar zuwa cikin keji.

By monosomy jima'i chromosomes sakamakon a wani tayi a wadda ta XO karyotype. Clinical buɗi na karyotype - Turner ciwo. Tamanin cikin dari na lokuta daga wani mutum ɗari bayyanar monosomy na X chromosome ne saboda take hakkin meiosis baby daddy. Wannan shi ne saboda nondisjunction X kuma Y chromosomes. Amma, 'ya'yan XO karyotype aka kashe a cikin mahaifa.

Bisa ga jima'i chromosomes trisomy ne zuwa kashi uku iri: 47 XXY, XXX 47, 47 XYY. Klinefelter ta ciwo ne Trisomy 47 XXY. Tare da irin wannan karyotype damar kai wani yaro raba hamsin-hamsin. A sabili da wannan ciwo zai iya zama wani nondisjunction na chromosome X, ko X kuma Y nondisjunction spermatogenesis. Biyu da na uku karyotypes iya kawai faruwa a daya daga cikin dubban mata masu ciki, sun kusan ba ya faruwa a mafi yawan lokuta, masana sami quite da hatsari.

• polyploidy

Wannan gene maye gurbi hade da canje-canje a cikin haploid sa na chromosomes. Wadannan kaya za a iya tripled da hudu. Triploids sun fi kamu kawai idan akwai wani yunkri zubar da ciki. Akwai lokatan da dama lokuta inda uwar gudanar ya yi irin wannan jariri, amma su duka sun mutu kafin kai da shekaru da kuma watan jiya. Sassan gene maye gurbi a cikin hali triplodii sa da kuma cikakken watsawa na nondisjunction na chromosome sets ko dai mace ko namiji jam sel. Har ila yau, inji iya bauta wa wani biyu hadi da kwai. A wannan yanayin, akwai degeneration daga mahaifa. Wannan abu akan sake haihuwa da aka kira matauni ciki. Yawanci, wadannan canje-canje kai ga ci gaban jaririn ta shafi tunanin mutum da kuma physiological cuta, zubar da ciki.

Wanne gene maye gurbi suna hade da wani canji a chromosome tsarin

A tsarin canje-canje ne saboda abin da chromosomal hutu (karaya) chromosome. A sakamakon wadannan chromosomes suna da alaka, ya karya baya bayyanar. Wadannan gyare-gyare iya zama unbalanced da kuma daidaita. Daidaita da wani ragi ko karancin abu, duk da haka ba su nuna. Su na iya faruwa ne kawai a kuma waɗannan lokuta inda a-site halakar da chromosome wani gene cewa ne aikin muhimmanci. A daidaita sa na gametes iya bayyana unbalanced. A sakamakon wannan gamete hadi iya haifar da bayyanar da tayin da wani unbalanced chromosome sa. Tare da wannan sa tayin kiwata a yawan malformations bayyana tsanani pathologies.

Iri tsarin gyare-gyare

Gene maye gurbi faruwa a matakin gamete samuwar. Don hana wannan tsari iya ba, kuma ba zai iya ba, haƙĩƙa san cewa irin wannan maye gurbi iya faruwa. Tsarin gyare-gyare da dama iri.

• deletions

Wannan canji ne saboda asarar wani ɓangare na chromosome. Da zarar wannan rata zama guntu chromosome, kuma ta ciwo mai tsananin part aka rasa a cikin m cell division. Interstitial deletions - wannan shi ne yanayin a lokacin da daya chromosome ta kakkarye, a wurare da dama. Wadannan chromosomes ne yawanci nuna nonviable tayin. Amma akwai lokuta inda yara sun tsira, amma suna da saboda wannan sa na chromosomes ya Wolf-Hirschhorn ciwo, "cat ta kuka."

• kwafi

Wadannan gene maye gurbi faruwa a matakin kungiyar na DNA biyu. M kwafi ba zai iya zama cikin hanyar wannan munanan cewa sa deletions.

• translocation

Translocation auku saboda da canja wurin da kwayoyin abu daga daya chromosome zuwa wani. Idan akwai wani katsewa da dama chromosomes kuma suka musanya segments, shi ya zama mai hanyar retsiproktnoy translocation. A karyotype wannan translocation yana da kawai arba'in da shida chromosomes. The sosai guda translocation kawai saukar da wani cikakken bincike da kuma nazarin chromosomes.

Canje-canje a cikin nucleotide jerin

Gene maye gurbi suna hade da wani canji a cikin nucleotide jerin, a lokacin da aka bayyana, a wani gyara na tsarin wasu sassan na DNA. By irin maye gurbi effects ya kasu kashi biyu iri daban-daban - ba tare da wani firam motsi da kuma motsi. Don san daidai abin da ya haddasa canje-canje na DNA, shi wajibi ne don la'akari da kowane irin dabam.

Frame shift maye gurbi, ba tare da

Wadannan gene maye gurbi suna hade tare da canji da kuma maye tushe nau'i-nau'i a cikin DNA tsarin. Idan irin wannan substitutions ba rasa da DNA tsawon, amma za a iya rasa da kuma maye da amino acid din. Akwai yiwuwar cewa tsarin da gina jiki ne kiyaye, shi zai zama da degeneracy daga cikin kwayoyin code. La'akari da cikakken bayani game da biyu zažužžukan: sauyawa, kuma ba tare da amino acid substitutions.

Maye gurbi da ya maye gurbin amino acid

Ya maye gurbin wani amino acid saura a cikin polypeptide kira missense maye gurbi. A haemoglobin kwayoyin akwai hudu mutum sarƙoƙi - biyu "da kuma" (shi ne located in sha shida chromosome), da kuma biyu "b" (coding a cikin goma sha ɗaya chromosome). Idan "b" - wata al'ada iyaka, kuma akwai mutum ɗari da arba'in da shida amino acid sharan a tsarinta, da kuma na shida ne glutamic, da haemoglobin ne na al'ada. A wannan yanayin, da glutamic acid da za a shigar wanda ke aiki GAA triplet. Idan saboda maye gurbi GAA GTA maye gurbin, maimakon glutamic acid a cikin haemoglobin kwayoyin kafa valine. Saboda haka, maimakon na al'ada haemoglobin HbA bayyana wani haemoglobin HbS. Saboda haka, aka canza daya amino acid, da kuma wani guda nucleotide zai sa tsanani tsanani cuta - sickle cell anemia.

Cutar da ake bayyana ta da cewa ja jini Kwayoyin suna dimbin yawa kamar lauje. Kamar yadda irin wannan, ba su iya zuwa yadda ya kamata isar da oxygen. Idan a salon salula matakin ne homozygous HbS / HbS dabara, shi take kaiwa zuwa mutuwar wani yaro a farkon yara. Idan dabara HbA / HbS, da ja da maikacin jini da rauni nau'i na canji. Wannan kadan canji ne mai amfani ingancin - jure cutar zazzabin cizon sauro. A waɗannan ƙasashe inda akwai hadarin na yin kwangila da zazzabin cizon sauro ne guda kamar yadda a cikin sanyi na Siberia, wannan canji yana da wani amfani quality.

Maye gurbi da amino acid din ba tare da maye

Nucleotide substitutions ba tare da musayar amino acid kira seymsens maye gurbi. Idan DNA yankin shigar da "b" - kewaye za a maye gurbin a GAA gag, sa'an nan saboda gaskiyar cewa kwayoyin code zai zama a wuce haddi, glutamic acid mayewa ba zai iya faruwa. sarkar tsarin da aka ba su canja ba, da erythrocytes ba zai zama gyare-gyare.

Frameshift maye gurbi

Wadannan gene maye gurbi suna hade da wani canji a cikin tsawon na DNA. Length iya zama karami ko ya fi girma, dangane da asara ko Bugu da kari na nucleotide nau'i-nau'i. Saboda haka, gaba daya dukkan tsarin da furotin da ake canza.

Intragenic danniya na iya faruwa. Wannan abu ya faru a lokacin da akwai wani wuri biyu maye gurbi cewa rama juna. Wannan ne lokacin da na shiga nucleotide nau'i-nau'i bayan daya da aka rasa, da kuma mataimakin versa.

Maganar banza maye gurbi

Wannan shi ne na musamman kungiyar na maye gurbi. Yana da rare, a ta, akwai bayyanar tasha codons. Wannan zai iya faruwa biyu a cikin asarar tushe nau'i-nau'i, kuma a cikin Accession. Lokacin da akwai tasha codons, da polypeptides kira tsaya a nan gaba daya. Kamar wancan iya samar da wata null allele. Yana kuma ba zai dace da wani daya daga cikin sunadaran.

Akwai irin wannan abu a matsayin intergenic danniya. Wannan shi ne wani sabon abu a inda da maye gurbi na daya gene cike da maye gurbi a cikin sauran.

ko canje-canje suna gano a lokacin daukar ciki?

Gene maye gurbi hade da canje-canje a cikin yawan chromosomes a mafi yawan lokuta za a iya ƙaddara. Don gano ko haihuwa lahani a cikin ci gaba da kuma Pathology, a cikin farkon makonni na ciki (daga goma zuwa goma sha uku makonni) wajabta nunawa. Wannan shi ne jerin sauki safiyo: wani shinge a kan jini samfurori daga yatsa da kuma jijiya duban dan tayi. A fetal duban dan tayi bi daidai da sigogi na duk extremities, hanci da kuma shugaban. Wadannan sigogi ne a wani karfi maras yarda nuna cewa jaririn yana da lahani a ci gaba. Don tabbatar da ko ƙaryatãwa game da ganewar asali dangane da sakamakon da jini gwajin.

Har ila yau, a karkashin kusa dubawa na likitoci ne gaba da mata, da jariran da suka iya yi a maye gurbi a kayyade matakin, an gaji. Wato, waɗanda mata, dangi na wanda suka kamu da wani yaro da shafi tunanin mutum ko kuma nakasassu, gano Down ciwo, Patau da sauran kwayoyin cututtuka.