Hans Spemann

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Hans Spemann, le oblidate patre del clonation

Pauches sape alique sur le vita de Hans Spemann (nascite in 1869 [mille octo centos sexanta e novem] in Stuttgart, Germania), un brillante homine de scientia qui faceva le prime exprimentos de clonation in 1902 (mille nove centos duo). Ille ganiava le Premio Nobel in 1935 (mille nove centos trenta e cinque).

Quando comenciava le seculo vinti il non habeva instrumentos microchirourgic, e pro facer su experimentos audace, Spemann esseva obligate a usar un capillo de su filia.

Con illo ille formava un lasso, passante lo circum le embryon de un salamandra in le prime stadios de disveloppamento. Ille tunc tirava le capillo e seccava nettemente le embryon a in duo partes. Le duo partes continuava lor disvellopamento usque producer duo salamandras complete.

Spemann non sapeva si su experimento producerea duo salamandras incomplete, e lo que ille faceva probava que que embryones in le prime stadios de disvellopamento esseva pluripotential, como nunc dicerea le embriologos. In altere parolas, illos esseva capace de formar ulle organo o texito. Plus tarde in lor disveloppamento, le cellulas de embryones se specialisa e pote producer solmente organos o texitos specific.

Post un altere serie de experimentos Spemann discoperiva le existentia de lo que ille appellava le "centro organisator" de un embryon. Ille anque discoperiva que post un certe periodo de disveloppamento, le cellulas individual de un embrion pote producer solmente organos e texitos specific.

Inter 1920 (mille octo centos e vinti) e 1930 (mille octo centos e trinta) Spellman prendeva le nucleo de un cellula de un embryon de salamandra e lo transfereva a un cellula embryonari de un altere animal, ex le qual ille habeva extrahite previemente le nucleo. Le resultato esseva un salamandra complemente normal. Iste methodo de transferentia nuclear nunc constituye le base del procedimentos moderne de clonation.

Post reciper le Premio Nobel in 1935, Spemann publicava su libro "Embryonic Development and Induction (Disveloppamento embrynic e induction), que tosto deveniva un obra de consulta in le qual, ultra exponer in detalio su travalios, ille proponeva un experimento phantastic: le clonation de organismos mediante le methodo de transferentia nuclear usante cellulas adulte.

Iste idea esseva troppo advantiate pro le decada de publication de su libro proque le instrumentos e materiales capace de manipular nucleos cellular in le forma requirite pro le experimento non existeva. Ma in 1952 (mille nove centos cinquanta e duo) le americanos Robert Briggs e Thomas J. King poteva clonar ranas de un maniera multo simile al methodo suggerite per Spemann. Infelicemente, ille non poteva vider iste successo proque ille habeva morite in 1941 (mille nove centos quaranta e un).

Post le clonation de ranas, veniva le ove Dolly in Scotia, le caballo Prometeo in Italia, le rata Ralph in France, le cervo Dewey in le Statos Unite, le gato CC (Carbon Copy) in le Statos Unite, cinque porcos in Scotia, e multe altere animales in diverse partes del mundo.

Omne iste complimentos haberea essite impossibile sin le prime passos que faceva Spemann ante plus que 100 (cento) annos, e indubitabilemente iste oblidate scientista debe esser honorate con le titulo del patre del clonation.

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Hans Spemann, the forgotten father of cloning.

Few people know anything about the life of Hans Spemann (born in 1869 [eighteen sixty-nine] in Stuttgart, Germany), a brilliant man of science who made the first cloning experiments in 1902 (ninteen oh two). He was awarded the Nobel Prize in 1935 (nineteen thirty-five).

At the beginning of the twentieth century, there were no instruments for microsurgery, and to perform his audacious experiments, Spemann was obliged to use a hair from his daughter's head.

With it he made a lasso, encircling it around a salamander embryo in the first stages of development. He then pulled on the hair and neatly cut the embryo into two parts. The two parts continued their development until they produced two complete salamanders.

Spemann did not know whether his experiment would produce two incomplete salamanders, and what he did proved that embryos in the first stages of development were pluripotential, as embryologists would now say. In other words, they were capable of forming any organ or tissue. Later on in their development, the cells of embryos become specialized and can produce only specific organs or tissues.

After another series of experiments Spemann discovered the existence of what he called the "organizing center" of an embryo. He also discovered that after a certain period of development, the individual cells of an embryo can produce only specific organs and tissues.

Between 1920 (nineteen twenty) and 1930 (nineteen thirty) Spellman took the nucleus of a cell from a salamander embryo and transferred it to an embryonic cell of another animal, from which he had previously extracted the nucleus. The result was a completely normal salamander. This method of nuclear transference is now the basis of modern cloning procedures.

After receiving the Nobel Prize in 1935, Spemann published his book "Embryonic Development and Induction," which soon became a reference work in which, besides explaining his work in detail, he proposed a fantastic experiment: cloning organisms by means of nuclear transfer using adult cells.

This idea was too advanced for the decade when his book was published because the instruments and materials capable of manipulating nuclear cells in the ways required by the experiment did not exist. But in 1952 (nineteen fifty two) the Americans Robert Briggs and Thomas J. King were able to clone frogs in a way that was very similar to the method suggested by Spemann. Unfortunately, he was not able to see this success because he had died in 1941 (nineteen forty-one).

After the cloning of frogs came Dolly the sheep in Scotland, Prometeo the horse in Italy, Ralph the rat in France, Dewey the deer in the United states, CC (Carbon Copy) the cat in the United States, five pigs in Scotland, and many other animals in various parts of the world.

All these accomplishments would have been impossible without the first steps Spemann made more than 100 (one hundred) years ago, and this forgotten scientist should unquestionably be honored as the father of cloning.