In the next decades, humanity will have to find an answer to the enormous challenge to “feed the world” (as defined by the FAO), caused by the fast-growing world population and its increasing wealth. The global consumption of animal protein will likely double by 2050. A considerable part of the increased food demand will be answered by chicken products (both eggs and meat).

Chickens have the lowest greenhouse gas production of all terrestrial livestock species, and in addition have an exceptionally good feed conversion ratio. This makes chickens a relatively environmental-friendly and also a financial-rewarding livestock animal. However, modern chicken production has a high risk for disease spreading: chickens are housed in chicken houses at high stocking density and preventive use of antibiotics is undesirable.

Thus, the main interest of our chair of Reproductive Biotechnology is focused on understanding the chicken immune system to equip the chicken with better tools to fight of diseases. We are one of the very few groups worldwide with the skill set to develop and utilise genetically engineered chickens for use in immunological research. 

The chicken immune system 

Our core business is the generation of genetically modified chickens to elucidate the unique features of the innate and adaptive immune systems in chickens.

Adaptive immune system

The absence of B and T cell knockout chickens has been a persistent obstacle for chicken immunologists for decades. However, we have successfully generated B and T cell knockout chickens. These chickens are an essential tool to understand the unique features of the chicken adaptive immune system and to utilize this knowledge to improve the chicken’s disease resistance.

Innate immune response

Comparative studies difference between chicken and duck clearly illustrates a remarkable difference in viral susceptibility. Comparison of the genome of both species led us to the identification of specific innate immunity-genes that are evolutionary lost in the chicken. We restored these lost genes in the chicken genome to investigate their effect on the chicken’s (anti-viral) immune response and to use this knowledge to improve their innate immune system.

In addition we introduce precise edits into the chicken interferon system in order to analyze the role of interferon in the avian innate immune respsonse against pathogens.

Genetic engineering of chickens

The chicken offers a great opportunity to study mechanisms that regulate development. Its phylogenetically distance from mammals gives the chicken substantial advantages to this, such as easy access to the embryo. The culture and genetic modification of primordial germ cells made it possible to introduce specific gene mutations into the germline. We have and are generating several lines of transgenic chickens, such as the B and T cell knockout chickens, in order to study different physiological functions. Our primary focus is, as mentioned, the chicken immune system. However, we also use our knowledge on genetic engineering to collaborate on other societal-relevant issues, such as understanding sex development in chickens to prevent culling of one-day-old male chickens.

Chicken models for biomedical research

Our chair created Cas9 endonuclease-expressing chickens, which is our newest revolutionary tool to facilitate gene editing in chickens. This fascinating model offers an easy and fast way to manipulate the chicken genome by simple delivery of single guide RNAs (sgRNA). The rapid genome editing allows easy physiological studies of specific genes, as well as direct comparison of gene functions between chicken and mammalian species. This created an unprecedented opportunity for different research fields, such as evolutionary biology. Furthermore, we use our expertise to create chicken models for biomedical research for human diseases, such as cancer. Moreover, this reduces the number of experimental animals necessary for the screening and development of therapeutic agents for such diseases.

This is in a nutshell the work we do at the chair of Reproductive Biotechnology. We are always looking for new opportunities and collaborations. Feel free to contact us!