Transgenic and Experimental Animal Unit

>>>Transgenic and Experimental Animal Unit

The unit provides high-level support in the field of animal genome modification (mice, rats and ruminants). We offer several techniques, such as pronuclear
microinjection, homologous recombination in embryonic stem cells, lentiviral injection, transposons and the revolutionary CRISPR / Cas9 system. We also provide cryopreservation, in vitro fertilization and embryo rederivation in mice. Besides, the unit supplies mice and rats with high genetic and health status for researchers within the institute and the region.

Since 2007 we have worked with national and international biotechnology companies offering in vivo biological assays in mice and rats, under GLP standards. We receive undergraduate and graduate students who do thesis using different technologies to obtain animal models. We also organize courses for technicians and scientists, and offer internships for technicians or veterinarians who administer their own services.

Our staff is member of organizations, such as the International Society for Transgenic Technologies (ISTT), the Institutional Articulation Committee (CAI), the
National Commission of Animal Experimentation (CNEA), the Uruguayan Association of Animal Science and Technology Laboratories (AUCyTAL), and the Federation of South American Associations for Laboratory Animal Science (FESSACAL)

PhD Ana Paula Mulet
PhD Ana Paula MuletMolecular Biology Technician
MSc Geraldine Schlapp
MSc Geraldine SchlappReproductive technology expert
MSc María Noel Meikle
MSc María Noel MeikleReproductive technology expert
TMN Ana Paula Arévalo
TMN Ana Paula ArévaloRadioisotope technician, MSc student
BSc Gabriel Fernández
BSc Gabriel FernándezAnimal Facility technician
Sergio Ancheta
Sergio AnchetaAmimal keeper
Andrés Pereyra
Andrés PereyraAmimal keeper
Nicolás Fiore
Nicolás Fiore Amimal keeper
Joaquín González
Joaquín González Maintenance
  • Gene editing in rodents

  • Gene editing in ruminants

  • Cryopreservation of embryos and mammals sperm

  • In vitro fertilization of rodents and ruminants


  • Animal Facility: SPF (Specific Pathogen Free) and Conventional area

  • Microinjection Laboratory

  • Assisted Reproduction Techniques Laboratory (ART)

  • Molecular Biology Laboratory


  • Generation of transgenic animals using CRISPR / Cas9 technology, pronuclear microinjection of DNA fragments, gene-targeting in embryonic stem cells, Sleeping Beauty Transposons technology.

  • Cryopreservation of embryos and sperm.

  • Rederivation of murine lines

  • In vitro fertilization of murine lines

  • Crosses and maintenance under SPF and conventional conditions of various strains mice (C57BL / 6J, BALB / cJ, DBA / 2J, Nude, several hybrids and about 30 different transgenic lines). Approximate production (currently): 2.000 mice per month.

  • Immunomodulatory capacity assays of probiotic bacteria

  • Biological activity assays of recombinant erythropoietin. Our Bioterio is certified by the Ministry of Public Health

  • Toxicity tests for biotechnological products (EPO, Filgen, Interferon)

  • Production of polyclonal antibodies in mice

Users of the IP Montevideo bioterium


We offer training in:

  • Techniques for transgenic animals and assisted animal reproduction.

  • Management of BSL2 pathogens in experimental procedures.

For more information contact

  • CARD-IP Montevideo Practical course: Cryopreservation of embryos and murine sperm. Sept. 10-13, 2018. Institut Pasteur Montevideo. Funded by: UNI-Biolac and IP Montevideo. Supported by: CARD and Kumamoto University

  • “Alternative Methods to the Use of Experimental Animals: In vitro evaluation of irritation (TG 439) and skin sensitization (TG 442E)”. May 21-24, 2018. Institut Pasteur de Montevideo. Funded by: Premasul and L’Oréal. Supported by: Protemca, Aucytal,CNEA.

  • “Theoretical-Practical Course of Laboratory Animals”. March 13-21, 2017. (19 national and one international speakers, and 21 national students) Supported by FOCEM and PEDECIBA.

  • “Integrating IP Montevideo technologies”. Internal course of the IP Montevideo.
    October 2017.

  • “TRANSGENIC TECHNOLOGIES in MODELING HUMAN DISEASES: Principles, Associated technologies, Animal Management and Ethics”. June 2017, Athens, Greece. Co-organizers.

  • “Theoretical-practical course of laboratory animals”, authorized for B-technical accreditation by the CNEA. April 4-12, 2016.

  • International course and symposium “ADVANCES IN THE GENERATION OF GENETICALLY MODIFIED (GM) ANIMAL MODELS – International Mini Symposium: TRANSGENIC TECHNOLOGIES, THE LATEST TRENDS”. September 2015.

  • “Management, techniques of substance administration and sampling in mice”.Internal course for 20 researchers who use mice in the IP Montevideo Animal Facility.2012-2015.

  • International course “Genetics of laboratory rodents”. December 2008 and 2011.Co-organizer with the Functional Genetics Unit of the Institut Pasteur de Paris.

  • 2015‐2018 – New strategies for the cryopreservation of oocytes and ovine embryos produced in vitro.

  • 2015‐2018 – Development of inoculants for the mobilization of phosphorus as an input in agricultural production. Participation: researcher.

  • 2015‐2018 – Development and validation of processes for the study and valuation of nutraceuticals: creation of the first Uruguayan company. Participation: researcher.

  • 2016-2019 – Design and production of new variants of the follicle stimulating hormone (FSH) for its use in species of productive interest. Participation: researcher.

  • 2012-2016 – Study of the mechanisms responsible for the potential probiotic effects of the CNCM I-3690 Lactobacillus rhamnosus strain.

  • 2014-2016 – Evaluation by molecular imaging of the anti-Tn diabody in the murine model of lung cancer. Master’s Thesis.

  • 2014-2016 – Influence of progesterone on follicular development on oocyte maturation and fertility in sheep. Master’s Thesis.

  • 2014- 2016 – Effect of lipid content on the maturation and vitrification of oocytes ovine: Mechanism of action and its application to the production of in vitro embryos.

  • 2012 – 2014 – Cryopreservation of ovine embryos produced in vitro in different stages by means of two vitrification methods. Master’s Thesis.

  • 2013-2014 – Characterization of an inducible murine model for the study of insulin signaling pathways. Initiation scholarship in the investigation.

  • 2013-2014 – Derivation and characterization of a line of murine embryonic stem cells (ESC) Oct4-GFP in the absence of serum and murine embryonic fibroblasts (MEF). Initiation scholarship in the investigation.

  • 2011-2014 – A technological innovation for sheep reproduction in Uruguay: in vitro production of embryos and their large-scale application.

  • 2012-2014 – Applied environmental toxicology: risk evaluation to environmental anthropogenic estrogen exposure in a transgenic murine model Oct4-GFP.

  • Meikle MN, Schlapp G., Menchaca A., Crispo M. Minimum volume spatula MVD vitrification method improves embryo survival compared to traditional slow freezing, both for in vivo and in vitro produced mice embryos. Cryobiology.

  • Barrera N, Dos Santos Neto PC, Cuadro F, Bosolasco D, Mulet AP, Crispo M, Menchaca A. Impact of delipidated estrous sheep serum supplementation on in vitro maturation, cryotolerance and endoplasmic reticulum stress gene expression of sheep oocytes. PLoS One 13(6). (

  • dos Santos-Neto P.C., Cuadro F., Barrera N., Crispo M., Menchaca A. 2017. Embryo survival and birth rate after minimum volume vitrification or slow freezing of in vivo and in vitro produced ovine embryos. Cryobiology. 78(8): 14.

  • Menchaca A., Schlapp G., Meikle M.N., Crispo M. 2017. Transgenesis and Gene Edition in Mammals. Reference Module in Life Sciences. Elsevier. V.1: 1-9 pp (Book chapter).

  • Menchaga A., AP Mulet, P. Dos Santos Neto, M. Crispo 2017. Transgenesis and Gene Edition in Small Ruminants. Revista Brasileira de Reprodução Animal, v.: 41 1, 2017

  • Mulet AP, Perelmuter K, Bollati-Fogolin M, Crispo M, Grompone G. 2017. Forkhead Box Protein O1 is Linked to Anti-Inflammatory Probiotic Bacteria Acting through Nuclear Factor-κB Pathway. J Microb Biochem Technol Volume 9(3):074-081

  • A. MENCHACA; I. ANEGóN; B. WHITELAW; H. BALDASSARRE; M. CRISPO- New insights and current tools for genetically engineered (GE) sheep and goats. Theriogenology, p.: 1 – 10, 2016.

  • • A. MENCHACA; N. BARRERA; P. DOS SANTOS-NETO; F. CUADRO; M. CRISPO. Advances and limitations of in vitro embryo production in sheep and goats. Animal Reproduction, v.: 13 3, p.: 273 – 278, 2016.

  • Crispo M, Mulet AP, Tesson L, Barrera N, Cuadro F, dos Santos-Neto PC, Nguyen TH, Crénéguy A, Brusselle L, Anegón I, Menchaca A. Efficient Generation of Myostatin Knock-Out Sheep Using CRISPR/Cas9 Technology and Microinjection into Zygotes. PLoS One. 2015 Aug 25;10(8):e0136690. doi: 10.1371/journal.pone.0136690

  • Schlapp G, Goyeneche L, Fernández G, Menchaca A, Crispo M. Administration of the nonsteroidal anti-inflammatory drug tolfenamic acid at embryo transfer improves maintenance of pregnancy and embryo survival in recipient mice. J Assist Reprod Genet. 2015 Feb;32(2):271-5. doi: 10.1007/s10815-014-0378-x. Epub 2015 Jan 6.

  • P. DOS SANTOS; M. VILARIÑO; N. BARRERA; F. CUADRO; M. CRISPO; A. MENCHACA. Cryotolerance of Day 2 or Day 6 in vitro produced ovine embryos after vitrification by Cryotop or Spatula methods. Cryobiology, v.: 70, p.: 17 – 22, 2015.

  • Crispo M, Vilariño M, dos Santos-Neto PC, Núñez-Olivera R, Cuadro F, Barrera N, Mulet AP, Nguyen TH, Anegón I, Menchaca A. Embryo development, fetal growth and postnatal phenotype of eGFP lambs generated by lentiviral transgenesis. Transgenic Res. 2015 Feb;24(1):31-41. doi: 10.1007/s11248-014-9816-x. Epub 2014 Jul 22.

  • Crispo M, Van Maele L, Tabareau J, Cayet D, Errea A, Ferreira AM, Rumbo M, Sirard JC. Transgenic mouse model harboring the transcriptional fusion ccl20- luciferase as a novel reporter of pro-inflammatory response. PLoS One. 2013 Nov 12;8(11):e78447. doi: 10.1371/journal.pone.0078447.

  • M. CRISPO; SCHLAPP G; CÁRDENAS M; D. GONZÁLEZ-MACIEL; M RUMBO. Optimization of transgenesis conditions for the generation of CXCL2-luciferase reporter mice line. EJB Electronic Journal of Biotechnology, v.: 16 6, 2013.

  • A. MENCHACA; M. VILARIÑO; M. CRISPO; DE CASTRO T; E RUBIANES. New approaches to superovulation and embryo transfer in small ruminants. Reproduction Fertility and Development, v.: 22 1, p.: 113 – 118, 2010.

  • A. MENCHACA; M VILARIÑO; M. CRISPO; A PINCZAK; E RUBIANES. Day 0 Protocol: superstimulatory treatment initiated in absence of a dominant follicle improves ovarian response and embryo yield in goats. Theriogenology, v.: 68, p.: 1111 – 1117, 2007.