Morgan chromosomal chiphunzitso: tanthauzo, zinthu zazikulu ndi zochititsa

N'chifukwa chiyani ana amafanana ndi makolo awo? N'chifukwa chiyani mabanja ena kufalitsa matenda ena monga khungu mtundu, polydactyly, olowa hypermobility, enaake fibrosis? N'chifukwa chiyani chiwerengero cha matenda amene amakhudza okha akazi ndi ena - amuna okha? Today ife tonse tikudziwa kuti mayankho a mafunso amenewa ayenera anafuna mu chibadwa, mwachitsanzo DNA kuti mwana amalandira kholo lililonse. Ndi chidziwitso cha izi, sayansi yamakono afunika Thomas Hunt Morgan - chibadwa American. Iye anafotokoza ndondomeko anasamutsa mudziwe majini ndi zachitika pamodzi ndi anzake chromosomal chiphunzitso cha cholowa (zambiri amatchedwa khromozomu chiphunzitso cha Morgan), amene wakhala mwala wapakona wa chibadwa ano.

History of anapeza

Kungakhale kulakwa kunena kuti Thomas Morgan anali oyamba kukhala ndi chidwi pa nkhani ya kusintha kwa uthengawu ku maselo. The ofufuza woyamba amene ayesa kuzindikira udindo DNA cholowa tinganene kuti ntchito Chistyakov, Beneden, Rabl mu 70-80-ntchentche za m'ma XIX.

Panalibe microscopes amphamvu kuti athe kuwona dongosolo khromozomu. Ndipo mawu akuti "khromozomu" Ndiye, sanali. Iwo unayamba ndi German wasayansi Heinrich Valdeyr mu 1888.

German zamoyo Theodor Boveri chifukwa cha zatsopano wake anasonyeza kuti ofunikira zachibadwa za thupi zachilendo kwa mitundu nambala yake DNA, ndi kusadziletsa awo kapena kuchepa kumabweretsa malformations kwambiri. Patapita nthawi, maganizo akewo anali kwakukuru anatsimikizira. Tikhoza kunena kuti asakhale ndi vutoli chiphunzitso T. Morgan ali poyambira ake mfundo zikomo kufufuza Boveri.

Start kafukufuku

Kaphatikizidwe wa chidziwitso alipo pa chiphunzitso cha chibadwa, yothandiza ndi kukhala anakwanitsa Thomas Morgan. Monga chinthu zatsopano wake anasankha Ntchentche, osati mwangozi. Icho chinali chinthu chabwino kwambiri kwa maphunziro a kufala kwa uthengawu ku maselo - anayi okha khromozomu, chonde, lalifupi nthawi ya moyo. Morgan anayamba kufufuza pogwiritsa ntchito mizere yoyera Ntchentche. Posakhalitsa anapeza kuti maselo nyongolosi ya akonzedwa umodzi DNA, ndiye 2 m'malo 4. Morgan zafotokozedwa mmene wamkazi khromozomu X wamwamuna - ngati Y.

Kugonana-zogwirizana cholowa

Morgan a khromozomu chiphunzitso zasonyeza kuti pali zizindikiro kotsimikizika kugonana zogwirizana. Ntchentche, amene wasayansi ikuchitika zatsopano wake, chimenenso chimafotokoza ali ndi red-diso, koma chifukwa cha masinthidwe a mbewu izi anthu anali woyera-eyed anthu, ndi mwa iwo anali ambiri wamwamuna. Jini, amene ali ndi udindo kwa mtundu wa ntchentche diso isanafalikire pa X khromozomu, pa Y-khromozomu si. Kuti mwa akazi kudutsa, wina X khromozomu amene ali jini mutated, ndi ferruginous wamwamuna Mwina pamaso pa khalidwe mu mbadwa adzakhala chikugwirizana ndi pansi. Chophweka njira kusonyeza izi pa taperekachi:

• P: XX '× X'Y;
• F _1: XX, XY, X'X 'X'Y.

X - wamkazi khromozomu kapena jini popanda woyera wamwamuna diso; X 'azungu khromozomu jini cha maso.

Kumvetsa zotsatira ndizi:

• XX '- red-eyed wamkazi jini chonyamulira zapitazi diso. Chifukwa kukhalapo kwa wachiwiri X-khromozomu ndi mutated jini "overlaps" wathanzi, ndi kuwonetsera palibe mbali fenotayipi.
• X'Y - woyera-eyed wamwamuna, amene analandira kwa mayi X khromozomu ndi jini ZOOPSA. Pakukhala chimodzi chokha X-khromozomu ZOOPSA khalidwe kanthu kuti asalalikire, ndipo zikuoneka mu fenotayipi.
• X'X '- woyera-eyed wamkazi khromozomu tinatengera jini mutated kwa mayi ndi bambo. Wamkazi yekha ngati onse X-DNA kunyamula azungu jini cha maso, uwoneka mu fenotayipi lapansi.

The chromosomal chiphunzitso cha chibadwa Thomas Morgan anafotokoza limagwirira la cholowa cha matenda ambiri chibadwa. Chifukwa majini X khromozomu zambiri kuposa pa Y khromozomu, iwo anazindikira kuti ndi udindo zizindikiro kwambiri chamoyo. The X khromozomu kwa mayi opatsirana monga ana aamuna ndi aakazi, pamodzi ndi chibadwa udindo katundu wa thupi, zizindikiro kunja kwa matendawa. Pamodzi ndi X-zogwirizana pali cholowa Y-zogwirizana. Koma Y-khromozomu ndi okhawo amuna, chifukwa ngati izo zichitika kusintha kulikonse, izo zikhoza anadutsa pa yekha ana aamuna.

The chromosomal chiphunzitso cha chibadwa Morgan kumvetsa chito za kufala kwa matenda majini Komabe, mavuto kugwirizana ndi mankhwala, sikuloledwa mpaka tsopano.

kusinthanitsidwa

Pa phunzirolo, ndi mwana wa Thomas Morgan Alfred Sturtevant anapeza chodabwitsa kuwoloka-bwereza. Monga zatsopano wotsatira, ma yatsopano imene imachititsa zimachitika chifukwa cha kudutsa. Zinali iye amene amaswa njira zogwirizana cholowa.

Choncho khromozomu chiphunzitso T. Morgan anapatsidwa udindo wina ofunika - pakati DNA magazi kumachitika kuwoloka-, ndipo pafupipafupi ake anatsimikiza ndi mtunda pakati chibadwa.

chikhazikitso

Kuti dongosolo zotsatira za kafukufuku wawo wasayansi ndi, azipereka malo zoyambirira za chiphunzitso chromosomal a Morgan:

1. Zizindikiro zimadalira chibadwa chamoyo zopezeka DNA lapansi.
2. Majini a khromozomu wina anapatsira mbadwa zowalamulira. Mphamvu ya guluu wolimba ndi wamkulu, ang'onoang'ono mtunda pakati chibadwa.
3. The DNA magazi anati chodabwitsa kuwoloka-bwereza.
4. Kudziwa pafupipafupi kudutsa pa khromozomu zina, timatha kuwerengera mtunda pakati chibadwa.

Udindo wachiwiri wa chiphunzitso chromosomal a Morgan ndi Morgan otchedwa ulamuliro.

Kuzindikila

Zotsatira kafukufuku ankaonera kwakukuru. Morgan a khromozomu chiphunzitso anali yojambula mu zamoyo zaka mazana makumi awiri. Mu 1933, chifukwa atulukira udindo DNA chibadwa Nobel Prize anali kupereka wasayansi lapansi.

Patapita zaka zingapo, Thomas Morgan analandira Copley Zikho kuti wachita bwino kwambiri m'munda wa chibadwa.

Tsopano Morgan a khromozomu chiphunzitso cha chibadwa amaphunzira ku sukulu. Iye zoyenera nkhani zambiri ndi mabuku.

Zitsanzo chinkhoswe ndi cholowa pansi

Morgan a khromozomu chiphunzitso zasonyeza kuti katundu wa thupi ofunitsitsa ndi chibadwa anaika mu izo. Zotsatira zimachititsa kuti muli Thomas Morgan, anapereka yankho ku funso la kulanda matenda monga amapatsira mwana wake, syndrome Chiwoko, khungu, matenda Bruttona.

Anapeza kuti chibadwa zonse za matenda amenewa zili pa X khromozomu ndi akazi, matenda awa zimachitika kwambiri kamodzikamodzi, ngati khromozomu wathanzi angathe kunyalanyaza asakhale ndi vutoli ndi jini matenda. Akazi amene sadziwa za izo, angakhale onyamula matenda chibadwa, amene ndiye akuwonetseredwa mu ana.

Mu amuna, X-zogwirizana matenda kapena zizindikiro phenotypic kuoneka, chifukwa palibe wathanzi X khromozomu.

The chromosomal chiphunzitso cha chibadwa T. Morgan ntchito mu kusanthula mbiri banja matenda chibadwa.