ΠΟΝΤΙΚΙΑ με αντοχή στα ΠΟΝΤΙΚΟΦΑΡΜΑΚΑ

Νέα γενιά ποντικών, ανθεκτική σε ποντικοφάρμακα εμφανίζεται στην ΕΕ.

Η μεταφορά γονιδίων ανάμεσα σε διαφορετικά είδη ποντικών, οδήγησε σε αυτή την εξελικτική μεταβολή. Ο υβριδισμός των ποντικών οδηγεί στην παραγωγή στείρων ατόμων αλλά η φύση ανοίγει πάντα κάποιο παράθυρο για την απρόσκοπτη αναπαραγωγή των ειδών.
Οι απόψεις των επιστημόνων για το φαινόμενο των ανθεκτικών ποντικών διαφέρουν.  Υπάρχει η άποψη ότι τα ανθεκτικά άτομα ποντικών προέρχονται από τη διασταύρωση ευρωπαϊκών και αλγερινών ατόμων. Άλλοι επιστήμονες θεωρούν ότι η διαταραχή οφείλεται στα παρασιτοκτόνα που δημιουργούν ερμαφρόδιτα άτομα. Στα άφυλα αυτά άτομα συμβαίνει μεταφορά γονιδίων.

10 August 2011   'Super' mouse evolves resistance to most poisons

By Matt McGrath Science reporter, BBC World Service
Scientists say that some European house mice have developed resistance to the strongest poisons.

Genetic exchange
Professor Michael Kohn from Rice University in Houston, Texas, led the team of researchers who carried out the work. "Our study is so special because it involves hybridisation between two species of mouse that are 1.5-3 million years removed from each other. German and Spanish mice have rapidly evolved the trait by breeding with an Algerian species from which they have been separate for over a million years.
"Most of the offspring... do not reproduce, they are sterile - but there is a small window, which remains open for genes to be moved from one species to the other, and that's through a few fertile females - so there is a chance to leak genes from one species to another."
Professor Kohn believes that his research is an example of what scientists call horizontal gene transfer, a process normally seen in bacteria and plants but rarely in animals.
"There have been some accusations that we had oversimplified things by saying this is horizontal gene transfer - I believe that it is. But it is more special than that, because it has to overcome this hurdle of hybrid sterility in the first generation of offspring at the very least."
Other scientists aren't so sure. Dr Julie Dunning Hotopp is from the Institute for Genome Science at the University of Maryland, US. She says the house mouse story does not meet her definition.
"It's interesting work - but I wouldn't call it horizontal gene transfer, which I would say was gene exchange in the absence of sex.
"In many respects I don't think it's surprising, anytime you have a strong pressure like a pesticide, you will have the opportunity to have these changes.
Πηγή http://www.bbc.co.uk/news/science-environment-14462733