PGC	Primordial germ cell
cPGC	Circulating primordial germ cell
gPGC	Gonad-derived primordial germ cell
HH	Hamburger–Hamilton
RNA-seq	RNA sequencing
RT-qPCR	Reverse transcription quantitative real-time PCR
DEG	Differentially expressed gene
PCA	Principal component analysis
FPKM	Fragments per kilobase of transcript per million mapped reads
GO	Gene Ontology
KEGG	Kyoto Encyclopedia of Genes and Genomes
GSEA	Gene set enrichment analysis
ECM	Extracellular matrix
RIN	RNA integrity number
SEM	Standard error of the mean