Chii chromatin: tsananguro, mamiriro uye mashandiro

Nemakemikari dzepamusha genetics - nzira inokosha kudzidza kwayo chikuru zvinoriumba - majini uye okutodza. Munyaya ino tichakurukura zvinhu chromatin, tsvaka ayo marongerwo uye mashandiro muchitokisi.

Nhodzera - huru pfuma Nhau mhenyu

Pakati huru pezvakaitwa kuti munguva zvipenyu vanogara panyika, vari kufema, kudya kunovaka, kukura, kusarudzwa uye kubereka. Rokupedzisira basa iri rinokosha kupfuura kuti ndichengetedze upenyu pasi redu. kwete sei kuyeuka kuti murayiro wokutanga wakapiwa naMwari kuna Adhamu naEvha chaiva zvinotevera: ". Berekanai muwande" Pachiyero masero rokubereka nerevane rinoitwa pamwe nucleic acids (constituent fuma okutodza). zvivako izvi zvichakurukurwa munyaya zvinotevera.

Tinewo wedzera kuti richengetedzwe uye kupararira mashoko majini akatakurirwa vazukuru chete mashandiro kuti hakutsamiri nenhanho sangano evanhu, kuti nokuda utachiona uye utachiona, uye zviri pasi nokudenga vanhu.

Chii fuma yedzinza

In neKwayedza tikadzidza chromatin marongerwo uye mashandiro anoita izvo zvakananga novimba sangano nucleic asidhi mamorekuru. Swiss musayendisiti Miescher muna 1869 yeimwe vakanga dzakaonekwa ari nuclei masero ari zvirwere, vachiratidza ehupfumi pakati acids akavadana wokutanga nukleina uye ipapo nucleic acids. Mumaonero kemisitiri, izvozvo macromolecular remubatanidzwa - Polymers. monomers ava nucleotides kuva inotevera mamiriro: a purine kana pyrimidine nechigadziko, uye pentose vakasara vane orthophosphoric acid. Masayendisiti akawana kuti mhando mbiri nucleic acids anogona kuvapo ari mumasero: DNA uye RNA. Vari complexed pamwe mapuroteni yokuumba remubatanidzwa okutodza. Uyewo mapuroteni, nucleic acids vane akawanda kwevari spatial sangano.

Muna 1953 Nobel Prize akanga Watson uye Crick deciphered sechivako DNA. Zviri morekuru rinoumbwa necheni mbiri interconnected ne rehydrogen zvisungo yomuka pakati nitrogenous nezvigadziko pamusoro chinobva complementarity (chakatarisana adenine thymine chawo chiri pakatarisana cytosine - guanine). Chromatin marongerwo uye kushanda zvatiri kudzidza, ari morekuru unotora munhu deoxyribonucleic asidhi uye ribonucleic configurations siyana. On nyaya iyi, tinokurukura zvizere yakawanda chikamu "Levels of chromatin sangano."

Localization zviri pfuma yedzinza muchitokisi

DNA aripo izvi cytostructure sezvo chinoumba, uyewo organelles, vaikwanisa weboka - mitochondria uye chloroplasts. Izvi imhaka yokuti organelles izvi dzinotoita basa rinokosha muchitokisi: ATP kwetunhu, uye kwetunhu shuga uye okisijeni inotungamirwa mu chirimwa mumasero. Chakaita zvokugadzirwa organelles vanozopinda mubereki nekaviri lifecycle. Saka, mwanasikana masero ari mitosis (kupatsanura masero somatic) kana meiosis (paumbwe dzisingaoneki uye OVA) vanopiwa aida zvombo sero zvivako rine masero pamwe zvinovaka muviri uye simba.

Ribonucleic asidhi ine neketani mumwe uye ane hwakaderera samolecular uremu pane DNA. Akawana zvose mwoyo uye hyaloplasm, uye chikamu zhinji muchitokisi organelles: ribosomes, mitochondria, endoplasmic reticulum, plastids. Chromatin mu organelles izvi chokuita histone mapuroteni uye chikamu plasmids - dzeraundi namahwindo DNA molecules.

Chromatin mamiriro uye

Saka isu makasimbisa kuti nucleic asidhi huri fuma okutodza - the STRUCTURAL zviumbu yedzinza. chromatin zvavo pasi Erekitironi maikorosikopu ane chimiro granular kana filamentous hurongwa. Rine, pamwechete DNA, uye kunyange RNA mamorekuru, uye mapuroteni vachiratidza zvinhu zvivako uye zita histones. Zvose pamusoro hurongwa vari chikamu nucleosome. Ivo anowanikwa musimboti uye okutodza dzinonzi fibrils (shinda-solenoids). Nokupfupikisa zvose pamusoro apa, isu kusarudza kuti chromatin ichi. Izvi remubatanidzwa kunzwisisa kuti deoxyribonucleic acids uye yakananga mapurotini - histones. Ivo, kufanana Coils, vari muchikuvadza kaviri nezano DNA molecules vaite nucleosome.

Kwevari chromatin sangano

nhodzera fuma ane zvakasiyana chimiro, izvo zvinoenderana zvinhu zvakawanda. Somuenzaniso, chii pavaipfuura upenyu kutenderera anozadziswa muchitokisi; kugova nguva (metoz kana meiosis), kana kuti chakaita zvokugadzirwa presynthetic panguva interphase. Kubva chimiro solenoid, kana fibrils, sendarama nyore, pane zvimwe compaction kuti chromatin. Heterochromatin - kupfuura gobvu mamiriro, achiumbwa munyika intron zvikamu chromosome, izvo hazvibviri transcription. Panguva zororo masero - interphase, kana pasina nokupesana muitiro - heterochromatin karyoplasm yaiva musimboti peripherally, pedyo kwayo membrane. Simbiso zvenyukireya mukati postsynthetic Danho kunoitika muupenyu kunoita masero, i.e. pakarepo pamberi nokupesana.

Chii chinoratidza kuti condensation pamusoro nyaya yedzinza

Kuramba kuongorora mubvunzo "chii chromatin," Vaongorori vakawana kuti zvinoenderana chisimbiso-histone mapuroteni kuti, pamwe mamorekuru DNA uye RNA ari nucleosome. Zvinosanganisira pakubhadhara ina mapuroteni, akadana mombe uye linker. Panguva iyoyo pakati transcription (kuverenga mashoko kubva Gene Via RNA) nhodzera zvinhu nomazvo fused, uye inonzi euchromatin.

Pari kunyanya kuparadzirwa DNA molecules chokuita histone mapuroteni vari kudzidza. Somuenzaniso, vaongorori vakaona kuti chromatin yakasiyana loci zvakafanana chromosome yakasiyana siyana condensation. Somuenzaniso, mune nzvimbo aida mitotic chokurukisa chromosome filaments anonzi centromeres, zvinonyanya gobvu kupfuura telomeric zvikamu - magumo loci.

Majini-regulators uye chromatin

Pfungwa murau pakati Gene basa, vakasikwa French nhaka kwezvinhu Jakobho Monod, anopa pfungwa nokuvapo nzvimbo deoxyribonucleic acid, umo hakuna ruzivo nemamiriro puroteni. Yavanobata evasingatombonamati bureaucratic - managerial mabasa. Zita majini regulators, zvikamu izvi pamusoro okutodza kazhinji yaro mamiriro rusina-histone mapurotini. Chromatin, tsanangudzo rakanga kuitwa sequencing, ainzi rakavhurika.

Zvimwe zvidzidzo zvakanzi Vakawana kuti pane loci izvi dziri chinhu nucleotide kutevedzana kuti kudzivirira kuomerera DNA molecules mapuroteni inoramba. migove kwakadaro vanoumba iri pamutemo majini ndiwo: vanosimudzira ehansery activators. The compaction kuti chromatin mavari zvakakwirira, uye kureba izvi zvikamu Avharenji anenge 300 nm. Pane nzira Pakusarudza nokukanganisika rakavhurika chromatin mune kure nuclei umo kushandisa DNA-ase enzayemu. Iye akakurumidza anotanga loci okutodza, kushayikwa-histone mapurotini. Chromatin munzvimbo idzi rakashevedzwa hypersensitive.

Basa yedzinza fuma

Zvivako kusanganisira DNA, RNA uye puroteni inonzi chromatin, vanobatanidzwa muchitokisi ontogeny uye kuchinja sezvamunoita kwayo zvichienderana zvinyama mhando uye padariro kukura ane muviri rose. Semuenzaniso, mune epithelial masero ganda majini sezvo ehanser uye mutsigiri kwakadaro chakavhara mapuroteni repressors, uye pamutemo majini ava secretory masero ari intestinal epithelium uye vari kushingaira munzvimbo rakavhurika chromatin. Masayendisiti, nyanzvi dzinoongorora akawana kuti pane chikamu DNA kuti murege encode mapuroteni, nekurangarira anopfuura 95% womunhu genome. Izvi zvinoreva kuti majini masimba anopfuura vaya mhosva kwetunhu peptides. Pakatanga mitoo yakadai DNA chips sequencing akabvumira kuti uzive zvakaita chromatin, uye somugumisiro, kunonyora vanhu genome.

Studies ose chromatin kunokosha muzvinhu zvakadai sayenzi zvakadai genetics hwevanhu uye zvokurapa genetics. Izvi Rinobatanidzwa ane hasha zvakawedzera pamwero panowanikwa enhaka zvirwere - akafanana Gene uye mashoko okutodza. Early kuziva miedzo syndromes izvi kunowedzera chikamu zvakanaka Zvaifungidzirwa vari kurapwa kwavo.