Embryo Manipulation in Chickens

Abstract

Chicken embryo manipulation, especially germline manipulation, recently has progressed greatly by devising important experimental techniques, such as embryo culture and primordial germ cell (PGC) manipulation. Embryogenesis and embryonic development in chickens are affected by gravity at various developmental stages. Freshly collected PGC population seems to contain germline-competent PGCs in opposite-sex germline chimeric chickens, but these PGCs probably disappear from the population during in vitro culture. Long-term culture of chicken PGCs makes it possible to transfer foreign DNA into the germline and also contributes to preserving avian genetic resources. Propagation of endangered avian species could become possible via interspecies germline chimeras. Development of techniques producing somatic cell-derived offspring could also be useful to avian germline manipulation.

Gut Hormones and Regulation of Food Intake in Birds

“…Further studies might also be needed to clarify the relationship between adipokines and gut hormones in the appetite regulatory system in birds. Recent technical advances in avian transgenesis allow efficient extensions of experimental protocols and research areas ( Park et al , 2013 ; Naito 2015 ), and therefore, in the future, highly developed genome editing technology will contribute to understanding the physiological importance of each gut hormone in birds.…”

Expression of GFP Gene in Gonads of Chicken Embryos by Transfecting Primordial Germ Cells <i>in vitro </i>or <i>in vivo </i>using the PiggyBac Transposon Vector System

“…Primordial germ cells (PGCs) are progenitor cells of ova and spermatozoa and are one of the most appropriate cells for germline manipulation in chickens (Kuwana, 1993;Tajima, 2002Tajima, , 2013Naito, 2003Naito, , 2015. Exogenous DNA could be introduced transiently into the gonads of recipient embryos by transfecting freshly collected PGCs in vitro and then transferring them to recipient embryos (Naito et al, 1998).…”

CRISPR/Cas9 gene editing in a chicken model: current approaches and applications

“…In this stage, PGCs can be commonly acquired through gonad isolation and trypsinization. PGCs can transmit genetic information to next generations and are thus ideal for creating transgenic or gene-edited chickens (Bednarczyk et al 2002;Bednarczyk et al 2003; Van de Lavoir et al 2006;Naito 2015;Chojnacka-Puchta et al 2015;Sawicka et al 2015;Oishi et al 2016;Dimitrov et al 2016). However, PGCs are characterized by their low ability to induce effective and persistent transfection.…”

“…Additionally, there are several obstacles to this process, because germ cells are relatively transcriptionally quiescent and prone to switching off transgene expression (Seydoux and Braun 2006). Development of efficient methods for culturing chicken PGCs without the loss of germline competency (Song et al 2014;Naito 2015;Whyte et al 2015;Lee et al 2016) was a milestone that brought more possibilities for genetic modification and precise gene editing. The first transgenic birds were generated using PGCs isolated from chicken embryos (stage 11 H.H.)…”