High-grade transgenic somatic chimeras from chicken embryonic stem cells

Area of Science:

• Developmental Biology
• Stem Cell Research
• Avian Embryology

Background:

• Embryonic stem (ES) cells offer potential for developmental studies and genetic modification.
• Deriving and maintaining stable avian ES cell lines is crucial for research.
• Understanding the differentiation potential of chicken ES (cES) cells is key to their application.

Purpose of the Study:

• To derive and characterize male and female chicken embryonic stem (cES) cell lines.
• To assess the contribution of cES cells to somatic tissues in recipient chicken embryos.
• To investigate methods for enhancing chimerism frequency and extent using cES cells.

Main Methods:

• Derivation of cES cell lines from Stage X chicken embryos (EG&K).
• Culture of cES cells, maintaining diploid karyotype.
• Reintroduction of cES cells into Stage VI-X recipient embryos.
• Utilizing embryo irradiation and diapause for enhanced chimerism.
• Genetic modification of cES cells with a GFP transgene under the CX promoter.

Main Results:

• Stable cES cell lines were established and maintained diploid karyotypes.
• cES cells contributed extensively to all somatic tissues of chimeric embryos.
• High-frequency and high-extent chimeras were produced using optimized methods.
• GFP expression was widespread in somatic tissues of chimeric embryos.
• No germline contribution from cES cells was detected.

Conclusions:

• Chicken embryonic stem cells can effectively contribute to somatic tissues, enabling the creation of highly chimeric embryos.
• Optimized techniques involving recipient embryo irradiation and diapause significantly improve chimerism.
• While somatic integration is robust, germline contribution remains a challenge for current cES cell applications.
• The developed cES cell lines and methods provide a valuable tool for avian developmental biology and genetic studies.