Maternal factor-mediated epigenetic gene silencing in the ascidian Ciona intestinalis.
Epigenetic regulation of genes plays a critical role in achieving proper gene expression during development, and it has been reported that epigenetic modifications are associated with transposon silencing in many organisms. Here, we report a type of epigenetic gene silencing, maternal gfp/gene silencing (MGS), in the basal chordate Ciona intestinalis. A transgenic line of Ciona, Tg[MiTFr3dTPOG]45 (abbreviated as Tg45), which was created with the Minos transposon, has a tandemly arrayed insertion of gfp in the promoter region of Ci-CesA. Progeny of Tg45 showed a reduced level of GFP expression when eggs of Tg45 were fertilized with sperm of other gfp transgenic lines. Although the genotype is the same, animals developed from Tg45 sperm and the eggs of other transgenic lines did not exhibit this phenomenon, suggesting the involvement of a maternal cytoplasmic factor that influences GFP expression. The silencing starts during oogenesis and continues after fertilization without any tissue specificity. We found that post-transcriptional degradation of the gfp mRNA is involved in MGS.
Sasakura
Yasunori
Y
Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka 415-0025, Japan. sasakura@kurofune.shimoda.tsukuba.ac.jp
Suzuki
Miho M
MM
Hozumi
Akiko
A
Inaba
Kazuo
K
Satoh
Nori
N
D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism; D002938:Ciona intestinalis / Q000235:genetics* / Q000502:physiology; D019175:DNA Methylation; D005260:Female; D020868:Gene Silencing; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D009866:Oogenesis / Q000235:genetics*; D020871:RNA Stability
D049452:Green Fluorescent Proteins