IMPROVING METHODS TO OBTAIN TRANSGENIC RUMINANTS

FERNANDEZ Y MARTIN RAFAEL; BEVACQUA R; PEREYRA-BONNET F; SALAMONE D

Tucuman

Simposio; Simposio de Biología y Biotecnología de la Reproducción Animal. 3º Reunión Conjunta de las Sociedades de Biología de Argentina.; 2015

Reunión Conjunta de las Sociedades de Biología de Argentina

Animal transgenesis is directed primarily to the production of animal models of human diseases, to obtain therapeutic proteins and less so to improve animal production. Traditional transgenesis techniques are very inefficient and subject to particular species to be transformed. For example in ruminants has not yet managed to maintain embryonic stem cells so the most used technique in mice is not used , the transgenic blastocyst injection with ES cells. In these animals, the somatic cell nuclear transfer (SCNT ) is one of the techniques more used. However, SCNT has a low efficiency and also only few transgenics show desired expression patterns. This is mainly due to random integration of the transgene as concatemers that can lead to epigenetic silencing of transgene. Since 2006, the laboratory animal biotechnology is working to simplify and universalize transgenesis techniques. Using the gfp gene as a transgenesis marker, we approach the sperm-mediated gene transfer. This transgenesis was not detected in vitro fertilization or artificial insemination, but do so with intracytoplasmic sperm injection (ICSI). However this transgenesis was transient, without stably transgene incorporation into the genome. In recent years, we began using active transgenesis techniques based on the use of enzymes that actively promote the integration of the transgene. The meganuclease I-SceI homing systems and transposons were used with very promising results.