Sex-nasaba gado (definition)

Mafi yawa daga cikin kwayoyin (tare da m ware), nan gaba nasa ne wannan ko da nazarin halittu jima'i aka ƙaddara a lokacin da hadi auku, kuma ya dogara da abin da irin na jima'i chromosomes fada cikin wani zygote. A wannan yanayin, akwai wasu siffofin wanda zai iya zama na musamman wa maza ko mata na wani irin. Irin wannan ãyõyi kamar yadda idan inextricably nasaba da daya daga cikin wadannan jinsuna, "nasaba" zuwa bene. Mene ne wani jima'i-nasaba gado da kuma dalilin da ya sa wasu cututtuka shafi kawai maza ko mata kawai? Za mu yi kokarin amsa wannan tambaya da wuya.

Boy ko yarinya?

Kafin ka fara amsa tambaya, abin da yake jima'i-nasaba gado, shi wajibi ne mu fahimci yadda wannan hanyar akwai wani samuwar na mace ko namiji jiki. Kamar yadda masu karatu na wannan labarin ya kasance a cikin jinsin Homo sapiens, su lalle ne zai zama mafi ban sha'awa su koyi game da yadda wannan tsari ne da za'ayi a cikin mutane. Bukatar wani fahimtar abin da halittar jini na jima'i: gādon dabiu, jima'i-nasaba, fitowa a quite takamaiman sunadaran, da kuma bukatar fahimtar ka'idojin da samuwar kwayoyin na daban-daban mata da maza.

Saboda haka, a kowane mutum cell yana da 46 chromosomes. Daga cikin wadannan, wakilan daban-daban nazarin halittu jima'i 22 m nau'i-nau'i. Wadannan chromosomes ake kira "autosomes." Daya kawai biyu - jima'i chromosomes - da wakilan wani karfi da kuma adalci jima'i da wasu bambance-bambance. A mata, jima'i chromosomes ne m: suna da biyu X (X) - chromosome. A maza, da jima'i chromosomes da daban-daban tsarin, daya daga wanda ke X-nasaba, da kuma na biyu - V (y) - chromosome. Ba zato ba tsammani, da Y-chromosome daukawa a kananan yawan kwayoyin halittu. Sex-nasaba gado juna dogara a kan kwayoyin halittu da cewa an tura a kan jima'i chromosomes.

Hakazalika, jima'i gādo ba duk nau'in. Wasu tsuntsaye kada ku yi haƙuri da namiji a cikin genome Y chromosomes: wadannan motsa kawai na uwa X chromosome. Akwai kuma nau'in a wanda ci gaban da mace jiki na bukatar wani Y chromosome, namiji, a maimakon haka, suna da yan dako na biyu X chromosomes.

Homogametic da heterogamety

By abin da dalilai guda zygote "samun" biyu X chromosomes, yayin da wasu ne Y-chromosome? Wannan shi ne saboda gaskiyar cewa a lokacin maturation na gametes, watau meiosis, duk da qwai samu zuwa 22 "al'ada" jima'i chromosome da daya X chromosome. Wannan shi ne, a cikin mace jiki ne m gametes. Maniyyi Kwayoyin ne guda, akwai iri biyu: daidai da rabi daga cikinsu daukawa jima'i X chromosome, yayin da wasu "samun" Y-chromosome.

Floor, forming m gamete ta jima'i chromosomes, da ake kira "homogametic". Idan wani gamete daban-daban - ya heterogametic. Mutane heterogamety maza, mata ma homogametic.

Wanne maniyyi zai takin wani kwai dogara a kan kaddara. Saboda haka, tare da yiwuwar 50/50 zygote na'am biyu X-chromosomes ko X kuma Y chromosomes. Babu shakka, a cikin na farko harka, da yarinya za ta ci gaba a karo na biyu - da wani yãro. Hakika, da akwai waɗansu ware a cikin wani yanayi, da 'yan mata ne a cikin genome na U-chromosome ko suna dako wani wanda bai sa kwayoyin halitta, da cewa shi ne, a cikin kwayoyin jikinsu akwai daya kawai jima'i chromosome. Duk da haka, wannan shi ne - sosai rare harka.

Me alamar za a iya "nasaba" da kasa?

Yanzu cewa mai karatu ya san abin da jinsi halittar jini, gado, zaman masu alaƙa da kasa, za a fi gane inji. Chromosomes ne na musamman kafofin watsa labarai: ɗaukar cikin kowane jikin mutum ya zama ma'abũcin "library" na 46 kundin, wanda tattaunawa bayyana dukan halaye da kuma siffofin na jikinsa. The adadin bayanai da cewa yana kunshe ne a cikin kowane mutum cell, har zuwa 1.5 gigabytes! Bugu da kari, kowane chromosome ƙunshi takamaiman part: ido da kuma gashi launi, yatsa dexterity, da girma na gajere memory, da hali ya zama kiba ... Chromosomes ne sosai na musamman: wasu ke da alhakin metabolism, yayin da wasu - don ido launi, ko da kudi na jijiya matakai .. . Duk da haka, domin manyan kwayoyin halittu bayanai da aka rubuta a kan sunadarai na gina jiki - enzymes, wanda ƙayyade da fasali na aiki na mutum kwayoyin.

Sashe na daga cikin kwayoyin bayanai shigar wanda ke aiki da kuma jima'i chromosomes. Saboda haka, a cikin ãyõyin cewa an "da aka rubuta" a cikin wadannan chromosomes, za a iya canjawa wuri zuwa wakilan wani nazarin halittu jima'i: wannan shi ne jima'i-nasaba gene gādo. Saboda haka, za mu iya zana wani muhimmin ƙarshe. Idan gene aka located a kan daya daga cikin jima'i chromosomes, da masana kimiyyar magana game da sabon abu na gadon dabiu, jima'i-nasaba. A wannan yanayin, gādonsa na wadannan halaye na da yawan siffofin: su ne a hanyoyi da yawa za su bayyana kanta a daban-daban jinsosin kwayoyin.

A farko nazarin

Auren lura da cewa gādon ido launi a Drosophila fuskoki dabam-dabam ne kai tsaye dogara a kan jinsi na mutane da suka yi ne kambun da daban-daban alleles. A gene cewa kayyade ci gaban da ja-ido ne rinjaye a kan "fari-sa ido" gene. Idan namiji ja idanu, yayin da mace - fari, sa'an nan a ƙarni na farko zuriyarsu samu wani daidai adadin mata da maza tare da ja da fari da idanu. Idan muka samu zuriya daga namiji da fari da idanu da kuma ja-sa ido mace, ka samu wani daidai yawan namiji da mace ja-sa ido. Kamar wancan ne, namiji phenotype a recessive hali bayyana kanta akai akai fiye da mace. Wannan ya tilasta wa da itifaƙin cewa gene ido launi aka located a kan X chromosome, wanda ke nufin cewa gādon ido launi a Drosophila - shi ne gādon halaye, guda biyu tare da kasa.

Bayani dalla-dalla da nasaba da gado na kasa

Sex-nasaba gado yana da wasu halaye. Suna da alaka da gaskiya cewa Y-chromosome daukawa mai karami yawan kwayoyin halittu fiye da X chromosome. Saboda haka, domin da yawa kwayoyin halittu, wanda aka located a kan X chromosome, wanda ya faru a namiji jiki, babu alleles a kan Y-chromosome. Saboda haka, wani recessive gene cewa ya jũya a kan X chromosome ba zai iya zama allelic gene a kan Y chromosome, wanda ke nufin cewa shi dole zai bayyana a cikin phenotype.

Ya kamata bayyana a sama. Allele ne wani nau'i na guda gene. Allele iya zama na biyu na asali iri: mai rinjaye da kuma recessive. A wannan yanayin, da rinjaye allele a genotype dole bayyana kanta phenotypically da recessive - kawai idan shi da aka gabatar a cikin homozygous jihar. Alal misali, za ka iya sa gādon ido launi a cikin mutane. A launi dogara da adadin melanin a Iris pigment. Idan melanin kadan idanu zai zama haske, idan mai yawa - duhu. A wannan yanayin, domin duhu ido launi rinjaye allele ne alhakin idan ya na a cikin genome, yaron zai zama ruwan kasa-sa ido. Ba kome ko duka biyu genes ne rinjaye ko recessive daya, wato, ko da yaro a kan filaye da homo- ko heterozygous. Amma da idanu shude - gwada "matasa" maye gurbi, wanda aka sarrafawa da wani recessive allele. All blue-sa ido mutane ne yan dako na biyu recessive alleles, watau su ne homozygous ga tushen ido launi. Rinjaye gene, kamar yadda ya bayyana a sarari daga sunanta, ta mamaye recessive idan daya yaro a cikin genome na wani gene cewa shirya launi na Iris, rinjaye, recessive allele ba zai iya bayyana kansu phenotypically.

Duk da haka, jima'i chromosomes a cikin wannan yanayin ne daban-daban. Maza Y-chromosome ne daban-daban daga X chromosome a cikin size da kuma siffar: shi gaske kama shi ne ba giciye ba, kamar sauran na chromosome, da kuma harafin Y. Saboda haka, wasu daga cikin kwayoyin halittu, wanda aka located a kan shi zai nuna sama ko idan za a daya kawai recessive kwafa: wannan jima'i hadin ne daban-daban daga sauran iri gādo.

X-nasaba recessive cuta

Sex hadin, shi ne na bayar da muhimmanci ga kiwon lafiya halittar jini, domin a wannan lokacin akwai game da ɗari uku recessive genes cewa ana sarrafa a kan X chromosome da kuma haifar da kwayoyin cututtuka. Irin cututtuka sun hada da hemophilia, myopathy, murdede dystrophy, ichthyosis, m X chromosome ciwo, hydrocephalus, kuma da yawa wasu cututtuka.

Sex-nasaba gado a cikin mutane da aka yi kamar haka. Idan mahaukaci gene aka located in daya daga cikin X chromosomes mace, da 'ya'yanta mata samun rabin da kuma rabin na' ya'yansa maza. A wannan yanayin, da yarinya, wanda genome ya m chromosome, zama yan dako da cutar: a cikin phenotype na mutant gene ba a shafi kamar yadda 'yar sami wani al'ada X chromosome daga ubansa. Amma yaron zai sha wahala daga wannan cuta, wadda ke zuwa "samun" shi da gādo daga mahaifiyarsa, saboda rinjaye allele na gene a cikin Y chromosome ba. Wannan factor ne muhimmanci a yi la'akari lokacin da yankan shawara a kan ayyuka jima'i-nasaba gādo.

Gādo X-nasaba recessive cuta ne wajen rikitarwa hali. Alal misali, a irin wannan cuta, yawanci tsakanin zumunta na da haƙuri, da aka samu a cikin masu juna biyu kawu kuma uwan, wanda aka haifa daga baffanninku.

Dominatnye X-nasaba da cututtuka

Wadannan cututtuka zai iya faruwa a duka biyu mata da maza. Daya zai iya buga misalai na irin wannan gādo, jima'i-nasaba kamar yadda hypophosphatemic rickets da duhu hakori enamel.

Fama da X-nasaba rinjaye cuta na mata ne ko da yaushe biyu sau fiye da maza. Marasa lafiya mace da yiwuwar 50% na dukkan watsa cutar ga 'ya'yansu, da kuma rashin lafiya mutum - dai' ya'ya mata.

Wani lokaci, jima'i-nasaba gādo Yana za a iya lura a gwada rare cututtuka da suke mutuwa to namiji tayi haka mata qara alama kwatsam zubar da ciki.

Zai iya sa rashin iyaka gado misalai, jima'i-nasaba. Bari wannan wata cuta kamar yadda urinary pigment ko melanoblastoz Bloch-Sultsberga. Urinary pigment samu ne kawai a mata: a na mutuwa gene to namiji tayi. Jikin 'yan mata fama da wannan cuta, akwai rashes a cikin nau'i na kumfa. Bayan da rash tafi, fata pigmentation ne na hali a cikin nau'i na fesa da eddies. 80% da marasa lafiya, akwai wasu keta: malformations na kwakwalwa ci gaba da kuma kayan ciki, idanu kuma kwarangwal tsarin.

hemophilia

Akwai da dama daga hereditary cututtuka, ana samu ne kawai a daya jima'i. A matsayin misali na abin da wani jima'i hadin, hemophilia ne kusan kowane littafi. Hemophilia yake akwai wata cuta a cikin abin da jini ba coagulate. da yawa ayyuka aka sadaukar domin hemophilia tare da jima'i nasaba gado: Zaka iya cewa wannan shi ne kusan a littafi misali. Duk da cewa hemophilia ne m, ta zama da aka sani ga kusan kowa da kowa. Wannan ba abin mamaki: shi ne sun fi mayar da m hanya na Rasha tarihi. Ta sha wahala da sarki gãji Nicholas II Tsesarevich Aleksey.

Ko a kananan yanka a lokaci guda zai iya sa mai tsanani jini hasãra. Duk da haka, da hatsarin ba kawai zub da jini hade tare da mai illa fata mutunci. A tsanani barazana ga rayuwar marasa lafiya ne intraenteric, intracranial hemorrhage, kuma makogwaro, kazalika da zub da jini a gidajen abinci. A wannan yanayin, haemophilia ne m: marasa lafiya da rayuwa yarda canzawa kwayoyi, wanda ba su da halin high dace.

Kada mata wahala daga haemophilia?

Mutane da yawa kuskure yi imani cewa mata ba su sha daga hemophilia. Duk da haka, shi ne, ba haka: da adalci jima'i, ma, wahala daga wannan mummunan cuta. Duk da haka, shi ya faru sosai da wuya. Fiye da sau da yawa, mata suna dako na gene cewa predetermines cutar.

The mace-mai bãyar da daya daga cikin jima'i chromosomes yana da recessive gene predetermining incoagulability jini. Idan akwai wani genotype na rinjaye allele wannan gene, da cuta ba ya bayyana kanta. Duk da haka, idan wata mace yana da wani yãro, wanda ya shiga wani recessive gene, zai bayyana hemophilia. Amma ga hemophilia faru a cikin 'yan mata bukatar mace dako na gene aka aure zuwa wani mutumin da hemophilia (amma ko da a karkashin irin wannan yanayi, yiwuwar samun haihuwa wata yarinya za ta zama daidai da 25%). Irin haka da wuya lura: da farko, da hemophilia gene ne quite rare, kuma abu na biyu, mutanen da fama da wannan hatsari cutar da wuya tsira zuwa haihuwa shekaru.

Ma'anar halaye nazari jima'i hadin

Bincike na yadda za gādon jima'i-nasaba halaye ne na bayar da muhimmanci ga bil'adama. Wannan shi ne saboda da farko ya nuna gaskiyar cewa jima'i-nasaba gaji da yawa cututtuka, ciki har da kawo hadari ga rayuwar dan Adam. Zai yiwu a nan gaba za su iya haifar da m wajen zalunta irin cututtuka, dangane da sakamakon kai tsaye a kan mutum genome, wanda yake shi ne m na wani pathological allele. Bugu da kari, irin wannan bincike taka babban rawa wajen ci gaban na matakai domin kulawa da lifiya na jima'i-nasaba cututtuka. Wannan yana da muhimmanci musamman ga cututtuka da ake dangantawa da rayuwa cuta: A baya ka fara jiyya, mafi nasara za su iya cimma.

Auren bautar wani muhimmin wuri a cikin rayuwar dan Adam. Bayan duk wannan kimiyya iya bayanin yadda aiki na mutum kwayoyin halitta, ciki har da wadanda suke pathological ãyõyi. Akwai wani rukuni na cututtuka da lalacewa ta hanyar gado wanda jima'i chromosomes. Mene ne wani jima'i-nasaba gado ba? A definition ya furta cewa, canja, daga ãyõyin mu'ujizõji, abin da da alhakin genes, wanda aka located a kan jima'i chromosomes.