Primordial germ cells from chicken embryonic stem cells

描述（由申请人提供）：在Origin Therapeutics，我们已经获得了鸡胚胎干细胞（cES），这些细胞可以在培养物中保持较长的时间，并在嵌合体中广泛参与体细胞组织，并在低水平下参与种系。Origin的目标是利用这些cES细胞来创造转基因鸡，在鸡蛋中产生临床相关的药物蛋白。Origin已经建立了用高达160 kb的构建体稳定转染ES细胞的常规程序，并且已经用携带45 kb转基因的ES细胞产生嵌合体，所述45 kb转基因编码人单克隆抗体的重链和轻链组分的产生。该单克隆抗体仅在输卵管的管状腺细胞中表达，并输出到卵白色中。为了最佳生产蛋白质，需要完全转基因的鸡，这需要强大的种系传播。近年来，分化的体细胞已经从人和鼠ES细胞中衍生出来。最近，卵母细胞和精子也来源于小鼠ES细胞。在鸡中，PGCs通过脉管系统迁移到性腺。当在适当的时间注射外源性PGCs时，可以基本上定殖受体胚胎的生殖系。为了获得稳健水平的生殖系传递，本申请提出从胚胎干细胞衍生PGC，并用体外衍生的PGC定殖性腺。

DESCRIPTION(provided by applicant): At Origin Therapeutics we have derived chicken embryonic stem cells (cES) that can be maintained in culture for extended periods of time and contribute extensively to the somatic tissues in chimeras and at low levels to the germline. Origin's goal is to use these cES cells to create transgenic chickens producing clinically relevant pharmaceutical proteins in their eggs. Origin has established routine procedures for stable transfection of ES cells with constructs up to 160 kb and has produced chimeras with ES cells carrying a 45 kb transgene that encodes the production of the heavy and light chain components of a human monoclonal antibody. This monoclonal antibody is expressed exclusively in the tubular gland cells of the oviduct and is exported into egg white. For optimal production of proteins fully transgenic chickens are required necessitating robust germline transmission. In recent years differentiated somatic cells have been derived from human and murine ES cells. Most recently oocytes and sperm have also been derived from mouse ES cells. In the chicken PGCs migrate to the gonads through the vasculature. Exogenous PGCs, when injected at the appropriate time, can substantially colonize the germline of recipient embryos. To obtain robust levels of germline transmission this application proposes to derive PGCs from embryonic stem cells and to colonize the gonad with in vitro derived PGCs.