Transgenic chickens

Abstract

The development of transgenic chicken technology has lagged far behind that of mammalian species. Two reasons for this are that only a one-cell-stage oocyte can be obtained from a sacrificed hen and that the yolk prevents high-magnification microscopic observation of oocytes. Recently, several new methods have been developed that will enable the successful establishment of transgenic chickens. Retroviral vectors are used in many cases because of their ability to incorporate transgenes into host cell chromosomes in a highly efficient manner. These viral vectors are injected directly into the embryos, usually at the blastodermal stage. In some cases, primordial germ cells (PGCs) are infected in vitro and then implanted into recipient embryos. Methods that do not rely on retroviral vectors are also available for creating transgenic chickens. Long-term culture of PGCs permits the selection of stably transfected cells and implantation of the manipulated PGCs. In addition, embryonic stem (ES) cell systems are available; however, the induction of functional gametes from ES cells has not, to our knowledge, been successful. It is clear that recent developments suggest that chickens may be used as a valuable experimental genetic system.

Avian embryos and related cell lines: A convenient platform for recombinant proteins and vaccine production

“…Various transgenic animal species have the capability to produce recombinant proteins in their milk or eggs [6,29]. Transgenic avians, because of their short breeding time, simple management, and high productivity are of interest for recombinant therapeutic production [6,30]. Human monoclonal antibodies and therapeutic proteins produced in egg whites contain nearly correct posttranslational modifications (PTM) that enable them to be effective therapeutic agents [31][32][33].…”

Cell Shape and Cell Lineage Conversion

“…In this respect the poultry research community is presented with a rare opportunity. With a long history of making significant contributions to the developmental biology field (Stern, 2005), the birds are increasingly becoming a tractable model system for genetics (Nishijima and Iijima, 2013), cancer (Kain et al, 2014) and pluripotency (Alev et al, 2013;Jean et al, 2013;Sheng, 2014) studies. Poultry science researchers have the advantage of combining recent advances in these fields with avian resources often uniquely available to them to help establish the avian system as an attractive alternative research model for cancer, cancer EMT, ES cell maintenance and differentiation and its therapeutic applications.…”

Improvement of Chicken Primordial Germ Cell Maintenance In Vitro by Blockade of the Aryl Hydrocarbon Receptor Endogenous Activity

“…The manipulation of PGCs is very useful for producing transgenic chickens and also for preserving genetic material in avian species (Nakamura et al, 2010(Nakamura et al, , 2013Nishijima and Iijima, 2013). A lot of research has focused, therefore, on the study of PGCs and the way of improving their culture, since the major obstacle is to amplify these cells without losing their pluripotent properties.…”

“…A lot of research has focused, therefore, on the study of PGCs and the way of improving their culture, since the major obstacle is to amplify these cells without losing their pluripotent properties. In vitro longterm cultures of germline competent avian PGCs maintained in well-characterized conditions have been achieved (Han, 2009;Han et al, 2002;Naito et al, 2015;Raucci et al, 2015), and the use of PGCs in transgenic experiments for effective production of germline chimera has been established (Han, 2009;Han et al, 2002;Nishijima and Iijima, 2013). Considering the feasibility of current biotechnologies in the chicken, improvements in the maintenance of PGC characteristics for an extended period and the ability to promote their amplification or expansion further contribute toward improving effective systems for germline chimera production and avian genome manipulation.…”