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First calves from gene diagnosed embryos born at MTT Agrifood Research Finland

August 14, 2003

Results from quantitative trait gene mapping (QTL) have been utilised for the first time in the selection of bovine embryos. The genotypes of two genes affecting milk yield and composition have been analysed from pre-implantation embryo biopsies. The first four female calves with known milk production genotypes were recently born at the experimental herd of MTT Agrifood Research Finland, Jokioinen.

Even more important than the predicted milking potential of the calves is the method by which they were produced. Embryo diagnostics was used for the first time to genotype sex and multiple genes affecting milkproduction traits.

The MTT research group is internationally known for bovine gene mapping and embryo technology. "One of the advantages of our group is that genomics and reproduction are studied in one place," say senior research scientists Dr Johanna Vilkki and Dr Jaana Peippo. The research on embryo diagnostics has been funded by TEKES (The National Technology Agency of Finland).

Embryo diagnostics as a selection tool

Small biopsies were dissected from week-old embryos flushed from donor cows. The relevant chromosome regions were first pre-amplified by PCR from lysed biopsies. Using pre-amplification it was possible to produce enough material for the analysis of multiple loci. The genetic analysis of sex and milk gene genotypes was completed within 8 hours. The embryos were kept overnight in culture medium for the results, before they were selected according to genotype and transferred to recipient cows. The embryos recovered well from the biopsy and developed into normal calves (which were given old-fashioned women's names, Suvikki, Suoma, Saima and Seela, as is normal in Finland).

As gene mapping studies proceed, it should be possible to include diagnostics for genes affecting disease resistance in the method and also to select for health traits. "At present we are mapping genes affecting mastitis resistance in collaboration with five other European research teams" says Johanna Vilkki. Selecting for lower genetic susceptibility to mastitis will reduce economic losses and use of antibiotics.

Aiming at longevity

Embryo technology (MOET) has been utilised at Jokioinen within the ASMO-nucleus herd since 1997 as a collaboration between MTT and Alkiokeskus Oy (Embryocenter Ltd). The first in vitro produced calf (Menestys) was born in 1998, and a year later the first calf (Nopu) produced in vitro from an ovum taken from a live donor. The gene mapping team made a quantum leap in 2002-2003 when they detected variations in genes affecting milk production.

The research at MTT is aiming at longevity of cows, resulting from good health and production properties. Molecular genetics is used as a selection tool in sustainable breeding programmes. "We are not intending to use cloning or gene transfer for breeding purposes," say the researchers.

MTT Agrifood Research Finland