Basa okutodza nokugadzirwa kwawo. Ko okutodza muchitokisi?

Nyaya ino ichakurukura kuti chivako kuti eukaryotic masero, okutodza, mamiriro uye kushanda vari vakadzidza zvipenyu maindasitiri, inonzi cytology.

History yakawanikwa

Chikuru chezvinonhuwira muchitokisi musimboti, chromosome dzakafukunurwa remakore rechi19 kubudikidza nevatsvakurudzi vakawanda. A Russian zvipenyu I. Chistyakov akadzidza panguva mitosis (muchitokisi nekupesana), anatomist German Heinrich Wilhelm Gottfried of Waldeyer-Hartz yakawanikwa navo panguva kugadzirira histological kugadzirira uye inonzi okutodza, kuti ari staining mhuru kukurumidza mhinduro pezvivako izvi vari kudyidzana pamwe makemikari dhayi magenta.

Fleming waitsanangura yesayenzi uchapupu chii chinosara chiri kuteererwa okutodza mumasero kuti akashongedza musimboti.

External mamiriro okutodza

Izvi nemaziso inotungamirwa riri nuclei - anokosha organelles masero uye kushumira senzvimbo chekuchengeta uye kupararira enhaka mashoko ane muviri. Okutodza ane rinokosha chirungiso - chromatin. Zviri conglomeration choupfu filaments - fibrils uye granules. Mukuona namakemikari, remubatanidzwa iyi Linear DNA molecules (anenge 40%) chete dzakananga histone mapurotini.

Zvivako kusanganisira 8 peptides uye DNA molecules netsvuku vakamonyanisa pamusoro mapuroteni globules, sezvo Coils anonzi nucleosomes. Plot deoxyribonucleic asidhi unogadza 1.75 nokumukirana kumativi nomubato mugove uye ane chimiro ane ellipsoid vanenge 10 nanometers pakureba uye 5-6 pahupamhi. Kuvapo kwezvinhu izvi (okutodza) ari chinoumba anoshumira taxonomic chinhu eukaryotic masero. Zviri muchimiro nucleosomes okutodza kushanda sezvo kuchengetedzwa uye kupararira nemagene zvinoyemurika.

The kutsamira pamusoro nemamiriro okutodza muchitokisi kutenderera danho

Kana muchitokisi iri interphase, iyo inozivikanwa nokuva zvikuru kukura kwayo uye muviri, asi kushaya weboka, ivo okutodza mune mwoyo vane chimiro matete filaments despiralizovannyh - chromonemata. Kazhinji vanenge zvakanyatsobatana, uye nemaziso zviparadzanise muvira yoga hurongwa zvisingabviri. Panguva kutanga muchitokisi weboka, riri mumasero somatic inonzi mitosis, uye pabonde - meiosis, okutodza kutanga helical uye thicken, kuva kuoneka maikorosikopu.

Kwevari sangano okutodza

Zviumbu yedzinza - chromosome, inoongorora muudzame sainzi genetics. Masayendisiti akawana kuti nucleosomal shinda dzine DNA-histone mapuroteni dzinoumba zononoka wokutanga hurongwa. Rizere chiputiriso pamusoro chromatin mamiriro kunoitika nokuda paumbwe rokumusoro kurongeka - solenoid. Iye anoronga uye chisimbiso chinotokurudzira zvikuru kunzwisisa coiled they-Coil. Zvose pamusoro Masangano chromosome yomuropa vari kugadzirira masero kuti zviparadzanise.

Zviri mitotic kutenderera STRUCTURAL chairema yedzinza, iine majini ane DNA vari pfupi uye thickened kuenzaniswa filiform chromonemata interphase nguva vanenge 19 zviuru. Times. Ichi chiine chimiro chromosome tsanga mabasa izvo kutamira majini zvechadenga muviri, tazvigadzira kuti zviparadzanise somatic kana utachiona masero.

The Morphology of okutodza

okutodza basa kunogona kutsanangurwa nokudzidza kwavo morphological zvinhu zvakanakisisa kurondwa mune mitotic kutenderera. Zvinonzi akaratidza kuti chakaita zvokugadzirwa padariro interphase guru DNA muchitokisi kaviri nekuti mumwe mwanasikana sero inoumbwa kuparadzanise, inofanira kuva zvakafanana magene mashoko sezvo mubereki chepakutanga. Izvi zvinoitwa kuberekana rikurumidze - DNA kuzvipira doubling hwokurara nokuda enzayemu DNA polymerase.

In cytological gadziriro wakagadzirirwa panguva yacho metaphase ose mitosis iri chirimwa kana mhuka masero nemaikorosikopu zvakajeka kuti mumwe chromosome rinoumbwa zvikamu zviviri, akadana chromatids. In haizopereri maitikiro ose mitosis - anaphase uye kunyanya telophase - vaparadzane zvakakwana kunoitika apo mumwe chromatid inova yoga chromosome. It unotora ndichifunda nekuumbanidzwa morekuru reDNA, uyewo lipids, asidhi mapurotini uye RNA. Mineral zvinhu rine magnesium uye calcium yakawanda ions.

Kutsigira STRUCTURAL zvinhu chromosome

To chromosome basa muchitokisi rwaiitwa zvakazara, zviumbu izvi yedzinza vari chaiyo mudziyo - chikuru constriction (centromere), izvo haana spiralizuetsya. Kuti rwokuyera chromosome muzvikamu zviviri, akadana pamafudzi. Zvichienderana nzvimbo centromere, chromosome genetics Classified panguva wakaenzana akachinjikana (metatsentrichnye) neravnoplechie (submetacentic) uye akrotsentrichnye. In dzidzo chaiyo chepuraimari constrictions vari kuumbwa - kinetochores, izvo dhisiki-kufanana mapuroteni globules riri mativi ose centromere. Sami kinetochores ine zvikamu zviviri: zvokunze kuonana microfilaments (Threaded chokurukisa) akabatana navo.

Akaroromesawo filaments (microfilaments) iri zvachose akarayira kuparadzirwa chromatids api aizova chromosome pakati masero mwanasikana. Vamwe okutodza mune mumwe kana kupfuura yechipiri constrictions, izvo zvisina kubatanidzwa mitosis, sezvo izvi varege abatane shinda chokurukisa, asi idzi (yechipiri constrictions) kugovera kudzora kwetunhu nucleoli - organelles kuti vane basa paumbwe ribosomes.

Chii chinonzi karyotype

Anozivikanwa nhaka kwezvinhu Morgan, N. Koltsov, Sutton mukutanga remakore rechi20, akanyatsokopwa akadzidzawo chromosome marongerwo uye mashandiro ari somatic uye nembeu masero - gametes. Vakawana kuti sero ose vose kwemarudzi hwokufananidzira imwe mari okutodza vane yakananga chimiro uye kukura. Zvakanga hwaratidza kuti raora okutodza mune musimboti masero somatic rinonzi karyotype.

Dzakakurumbira mabhuku karyotype rinowanzoshandiswa kwaenzaniswa chete chromosome yakatarwa. Kutaura zvazviri, hazvisi mungashandisa pfungwa. Semuenzaniso, karyotype hwevanhu 46 okutodza mune nuclei masero somatic uye anosarudzwa zvavo payakavakirwa 2n. Asi masero zvakadai, zvakadai hepatocytes (chiropa masero) vane nuclei shoma, avo chromosomal mukwanisi runotaurwa sezvo 2n * 2 = 4n kana 2n * 4 = 8n. Kureva nhamba okutodza mumasero izvi zvichava anopfuura 46, kunyange zvazvo karyotype ose hepatocytes riri 2n, zvino pane 46 okutodza.

Nhamba okutodza mune utachiona masero nguva kaviri kupfuura somatic shoma (mumasero muviri), ichi yakatarwa anonzi haploid uye anonzi n. mamwe masero ose mumuviri vane kutaridza 2n, inonzi diploid.

VaMorgan chromosome dzidziso nhaka

American geneticist Morgan vawana mutemo chokuita nhaka majini, kuitisa kuedza pamusoro hybridization michero enhunzi, michero nhunzi. Kuburikidza tsvakurudzo ake, mashandiro kurara okutodza nemasero vakanga vakadzidza. Morgan akaratidza kuti majini iri pedyo loci zvakafanana chromosome, runonyanya nhaka pamwe chete, i.e. ari batira. Kana majini riri pamusoro chromosome kure mumwe, pakati hanzvadzi okutodza zvinogoneka takayambuka-pamusoro - kugoverana zvepaIndaneti.

Nemhaka kutsvakurudza naVaMorgan, vakasikwa nemagene mepu, naro kudzidza mashandiro okutodza uye kushandiswa kwawo kwakadzama Genetic Counseling yokutaura nyaya zvichiita pathologies okutodza kana majini anokonzera nhaka zvirwere muvanhu. Kukosha vafunga masayendisiti, zvakaoma kuona.

Munyaya ino, zvatakurukura marongerwo uye kushanda okutodza, izvo yavanobata muchitokisi.