Knock-Out of Retrovirus Receptor Gene in the Chicken Confers Resistance to Avian Leukosis Virus Subgroups A and K and Affects Cobalamin (Vitamin B)-Dependent Level of Methylmalonic Acid.

The chicken Tva cell surface protein, a member of the low-density lipoprotein receptor family, has been identified as an entry receptor for avian leukosis virus of classic subgroup A and newly emerging subgroup K. Because both viruses represent an important concern for the poultry industry, we introduced a frame-shifting deletion into the chicken locus with the aim of knocking-out Tva expression and creating a virus-resistant chicken line. The knock-out was prepared by CRISPR/Cas9 gene editing in chicken primordial germ cells and orthotopic transplantation of edited cells into the testes of sterilized recipient roosters.

Precise CRISPR/Cas9 editing of the NHE1 gene renders chickens resistant to the J subgroup of avian leukosis virus.

Avian leukosis virus subgroup J (ALV-J) is an important concern for the poultry industry. Replication of ALV-J depends on a functional cellular receptor, the chicken Na/H exchanger type 1 (chNHE1). Tryptophan residue number 38 of chNHE1 (W38) in the extracellular portion of this molecule is a critical amino acid for virus entry.

Conservation of chicken male germline by orthotopic transplantation of primordial germ cells from genetically distant donors†.

Successful derivation and cultivation of primordial germ cells (PGCs) opened the way to efficient transgenesis and genome editing in the chicken. Furthermore, implantation of male PGCs from non-chicken galliform species into the chicken embryos resulted in cross-species germline chimeras and viable offspring. We have recently improved the PGC technology by demonstrating that chicken male PGCs transplanted into the testes of adult cockerel recipients mature into functional sperms.

Genetic Resistance to Avian Leukosis Viruses Induced by CRISPR/Cas9 Editing of Specific Receptor Genes in Chicken Cells.

Avian leukosis viruses (ALVs), which are pathogens of concern in domestic poultry, utilize specific receptor proteins for cell entry that are both necessary and sufficient for host susceptibility to a given ALV subgroup. This unequivocal relationship offers receptors as suitable targets of selection and biotechnological manipulation with the aim of obtaining virus-resistant poultry. This approach is further supported by the existence of natural knock-outs of receptor genes that segregate in inbred lines of chickens.

Simultaneous detection of chicken cytokines in plasma samples using the Bio-Plex assay.

A chicken multiplex cytokine assay (Bio-Plex) to detect four different cytokines (IL-2, IL-12, IL-10, and interferon gamma) simultaneously in plasma samples was designed. Most standard curves range between 1 to 5 pg/mL and 5,000 pg/mL, except for IFNγ with the range of 50 to 25,000 pg/mL. Such a chicken multiplex assay proved to be fast and reliable, and comparable in sensitivity, accuracy, and reproducibility to conventional enzyme-linked immunosorbent assays.