quarta-feira, 12 de abril de 2017

INCRÍVEIS PROPRIEDADES COGNITIVAS DOS POLVOS

                                           
                                                    os polvos conseguem ver com a pele

Sabe-se que os polvos têm capacidades surpreendentes e invulgares para animais invertebrados. 
Porém, encontrou-se agora algo, ao nível dos seus mecanismos moleculares, possivelmente associado a estas propriedades: os cefalópodes (grupo ao qual pertencem polvos, chocos, lulas...) têm capacidade de reescrever o seu ARN!
Abaixo transcrevo parte do artigo que se pode encontrar na íntegra, aqui

«... Squids, cuttlefish and octopuses do not follow the normal rules of genetic information, according to research published Thursday in the journal Cell. Their RNA is extensively rewritten, particularly the codes for proteins found in the animals' neurons.
Put simply, that's very weird. According to the central dogma of molecular biology, cells convert DNA sequences to RNA, which then creates proteins.
Imagine a library full of cookbooks, where you're not allowed to check anything out. But you are allowed to copy recipes as you need them. The copies must almost always be verbatim, as though done by a faithful scribe. RNA plays the role of scribe.
Sometimes, cells edit RNA, plucking out the molecule adenosine and inserting a molecule called inosine. University of Utah biochemist Brenda Bass discovered RNA editing three decades ago. “Everything we have learned in the 30 years since these were discovered says that these type of editing events usually don’t change codons,” Bass told The Washington Post, meaning that the edits to RNA did not change what proteins are created.
“The general view was that editing sites are being 'expelled' from the coding part of the RNA molecules,” Eli Eisenberg, a co-author of the new study and an expert in RNA editing at Tel Aviv University, wrote in an email to The Post. »
Muito temos ainda a aprender com estas discretas e fantásticas criaturas....