Jae Yong Han

Primordial germ cells (PGCs) from stage 27 (5.5-day-old) Korean native ogol chicken embryonic germinal ridges were cultured in vitro for 5 days. As in in vivo culture, these cultured PGCs were expected to have already passed beyond the migration stage. Approximately 200 of these PGCs were transferred into 2.5-day-old white leghorn embryonic blood stream, and then the recipient embryos were incubated until hatching. The rate of hatching was 58.8% in the manipulated eggs. Six out of 60 recipients

This study was undertaken to develop novel markers for chicken primordial germ cells (PGCs), which are of potentially enormous value in transgenic research. Gonadal cells collected from 5.5-day-old chicken embryos were cultured in a Dulbecco's minimal essential medium and the PGC colonies formed during the primary culture period were subcultured three times. Characterization of the PGCs with the candidate marker reagents was performed on the mixed cell population 2 hours after seeding, after the

The timing and biological events associated with germ cell specification in chickens have not been determined yet. In this study, we report the origin of primordial germ cells (PGCs) and germ plasm dynamics through investigation of the expression of the chicken homolog of deleted in azoospermia-like (cDAZL) gene during germ cell specification. Asymmetric localization of germ plasm in the center of oocytes from preovulatory follicle stages leads to PGCs being formed in the center. During cleavage

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) have facilitated the production of genome-edited animals for use as models. Because of their unique developmental system, avian species offer many advantages as model vertebrates. Here, we report the development of novel chicken models using the CRISPR/Cas9-mediated nonhomologous end joining repair pathway in chicken primordial germ cells (PGCs). Through the introduction of a donor plasmid c

DNA methylation is widespread in most species, from bacteria to mammals, and is crucial for genomic imprinting, gene expression, and embryogenesis. DNA methylation occurs via two major classes of enzymatic reactions: maintenance-type methylation catalyzed by DNA (cytosine-5-)-methyltransferase (DNMT) 1, and de novo methylation catalyzed by DNMT 3 alpha (DNMT3A) and -beta (DNMT3B). The expression pattern and regulation of DNMT genes in primordial germ cells (PGCs) and germ line cells has not been

The innate immune system, which senses invading pathogens, plays a critical role as the first line of host defense. After recognition of foreign RNA ligands (e.g., RNA viruses), host cells generate an innate immune or antiviral response <i>via</i> the interferon-mediated signaling pathway. Retinoic acid-inducible gene I (RIG-1) acts as a major sensor that recognizes a broad range of RNA ligands in mammals; however, chickens lack a RIG-1 homolog, meaning that RNA ligands should be recognized by o

Primordial germ cells (PGCs) are the founder cells for mature gametes, the vehicles by which individuals transmit genetic and epigenetic information to later generations. Since the 19^th century, avian species (chickens in particular) have been widely used for germ cell research. Previous studies have used chicken PGCs for a variety of research applications, including as a model for studies focusing on germline development. Other applications of chicken PGCs, including conservation eff

Transgenesis and genome editing in birds are based on a unique germline transmission system using primordial germ cells (PGCs), which is quite different from the mammalian transgenic and genome editing system. PGCs are progenitor cells of gametes that can deliver genetic information to the next generation. Since avian PGCs were first discovered in nineteenth century, there have been numerous efforts to reveal their origin, specification, and unique migration pattern, and to improve germline tran

Appropriate regulation of cell proliferation during embryogenesis is crucial for the maintenance of germness. An in-depth understanding of germ cell developmental processes may yield valuable information on germ cell biology and applied sciences. However, direct evidences about germ cell proliferation and cell cycling during avian embryonic development has not been well-studied. Thus, we explored chicken germ cell dynamics during embryonic development via flow cytometry employing a germ cell-spe

Biological bases for sexual differences in the brain exist in a wide range of vertebrate species, including chickens. Recently, the dogma of hormonal dependence for the sexual differentiation of the brain has been challenged. We examined whether sexually dimorphic gene expression in the brain precedes gonadal differentiation. Using the Affymetrix GeneChip Chicken Genome Array, we identified 42 female- and 167 male-enhanced genes that were differentially expressed in sex-specific brains from stag