Zakaj se celice starajo

Znanstveniki s Salkovega inštituta za biološke raziskave so v reviji Science objavili študijo o možganskih celicah podgane, v katerih so odkrili prisotnost t. i. proteina z izjemno dolgo življenjsko dobo.

Medtem ko običajni proteini živijo največ dva dni, so omenjeni proteini, ki so jih znanstveniki našli na površju jedra nevronov, stari toliko kot organizem sam, kar pa ne pomeni, da so v tako dobrem "stanju".

Odkritje nakazuje, da ti proteini lahko živijo toliko časa kot celica in da jih pri opravljanju njihovih "nalog" nikoli ne zamenjajo drugi, "sveži" proteini, kot je to značilno za delovanje drugih celic v telesu.

Now scientists at the Salk Institute for Biological Studies report that they have discovered a weakness in a component of brain cells that may explain how the aging process occurs in the brain.

gruntfürmich je 16. feb 2012 ob 21:13 izjavil:

če se celice ne bodo obnavljale, se bodo iz najrazličnejših razlogov same molekule oz vezi med njimi degradirale. in to bo pomenil propad najprej posameznih delov celice, nato pa celice same.

innerspace je 17. feb 2012 ob 13:32 izjavil:

Kako pride do degradacije kemijskih vezi? Mislis tule na 'poseganje' prostih radikalov ali kake gama zarke ali cisto nekaj tretjega ali cetrtega?

k4vz0024 je 26. jun 2012 ob 22:58 izjavil:

Celice so vnaprej programirane za smrt. Zato nimajo mehanizma, ki bi jim to preprečeval. Zelo verjetno je to v korist vrste, da se razvija......

k4vz0024 je 26. jun 2012 ob 23:18 izjavil:

Drži, vendar nesmrtnost individuuma ni cilj vrste, da razvije nove potencialno bolj uspešne individuume...

The cells from Henrietta's tumor were given to researcher George Gey, who "discovered that [Henrietta's] cells did something they'd never seen before: They could be kept alive and grow."[13] Before this, cells cultured from other cells would only survive for a few days. Scientists spent more time trying to keep the cells alive than performing actual research on the cells but some cells from Lacks's tumor sample behaved differently than others. George Gey was able to isolate one specific cell, multiply it, and start a cell line. Gey named the sample HeLa, after the initial letters of Henrietta Lacks' name. As the first human cells grown in a lab that were "immortal" (they do not die after a few cell divisions), they could be used for conducting many experiments. This represented an enormous boon to medical and biological research.[1]

LittleBug je 27. jun 2012 ob 21:58 izjavil:

Ja, sej rakaste celice se zelo veliko uporabljajo. Tako pridobivajo monoklonska protitelesa, ki se potem lahko uporabljajo kot pasivna cepiva (zdravljenje tetanusa, botulizma, davice...), zdravila (recimo artritis), lahko tudi za diagnostiko...

Je pa ironično, da je gospa umrla leta 1951, ampak njene rakave celice pa še danes živijo

tpleko je 1. jul 2012 ob 05:23 izjavil:

staranje in posledično smrt sta nujni sestavini evolucije. če ne bi bilo staranja in smrti tudi razmnoževanje ne bi bilo potrebno. brez razmnoževanja pa ni DNA napak in ni evolucije in ni napredka.

Meizu je 1. jul 2012 ob 07:49 izjavil:

Mislim, da to ne bo problem, ko bodo enkrat genetiko spravili do takšne stopnje, da bodo lahko producirali nove človeške vrste.

Okapi je 5. jul 2012 ob 14:15 izjavil:

Čisto tako, mimogrede, zeleni trdoživ (hidra) je precej bolj pogost kot jastog.
Zeleni trdo%C5%BEiv @ Wikipedia

O.

Yosh je 8. jul 2012 ob 20:47 izjavil:

Staranje je proces večih mehanizmov; cel nabor kompleksnih mehanizmov, kar se ne da razrešiti z uporabo laserja.
.

But how can alleles like this be passed from one generation to the next if they cause death? Dominant lethal genes are rarely detected due to their rapid elimination from populations. One example of a disease caused by a dominant lethal allele is Huntington's disease, a neurological disorder in humans, which reduces life expectancy. Because the onset of Huntington's disease is slow, individuals carrying the allele can pass it on to their offspring. This allows the allele to be maintained in the population. Dominant traits can also be maintained in the population through recurrent mutations or if the penetrance of the gene is less than 100%.