Epigenetics and the germline.
Epigenetic processes affect three stages of germline development, namely (1) specification and formation of primordial germ cells and their germline derivatives through lineage-specific epigenetic modifications, in the same manner as other embryonic lineages are formed, (2) a largely genome-wide erasure and re-establishment of germline-specific epigenetic modifications that only occurs in the embryonic primordial germ cell lineage, followed by re-establishment of sex-specific patterns during gametogenesis, and (3) differential epigenetic modifications to the mature male and female gamete genomes shortly after fertilisation. This review will detail current knowledge of these three processes both at the genome-wide level and at specific imprinted loci. The consequences of epigenetic perturbation are discussed and new in vitro models which may allow further understanding of a difficult developmental period to study, especially in the human, are highlighted.
Allegrucci
Cinzia
C
Division of Obstetrics and Gynaecology and Institute of Genetics, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK.
Thurston
Alexandra
A
Lucas
Emma
E
Young
Lorraine
L
D000818:Animals; D019175:DNA Methylation; D004627:Embryonic Induction / Q000235:genetics*; D044127:Epigenesis, Genetic / Q000502:physiology*; D005260:Female; D005775:Gastrula / Q000502:physiology; D005786:Gene Expression Regulation; D018392:Genomic Imprinting; D005854:Germ Cells / Q000502:physiology*; D006801:Humans; D008297:Male; D051379:Mice; D023421:Models, Animal; D013234:Stem Cells / Q000502:physiology