Dazl is a critical player for primordial germ cell formation in medaka.
The DAZ family genes boule, daz and dazl have conserved functions in primordial germ cell (PGC) migration, germ stem cell proliferation, differentiation and meiosis progression. It has remained unknown whether this family is required for PGC formation in developing embryos. Our recent study in the fish medaka (Oryzias latipes) has defined dnd as the critical PGC specifier and predicted the presence of additional factors essential for PGC formation. Here we report that dazl is a second key player for medaka PGC formation. Dazl knockdown did not prevent PGC formation even in the absence of normal somatic structures. It turned out that a high level of Dazl protein was maternally supplied and persisted until gastrulation, and hardly affected by two antisense morpholino oligos targeting the dazl RNA translation. Importantly, microinjection of a Dazl antibody remarkably reduced the number of PGCs and even completely abolished PGC formation without causing detectable somatic abnormality. Therefore, medaka PGC formation requires the Dazl protein as maternal germ plasm component, offering first evidence that dazl is a critical player in PGC formation in vivo. Our results demonstrate that antibody neutralization is a powerful tool to study the roles of maternal protein factors in PGC development in vivo.
Ministry of Education Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, College of Fisheries and Life Sciences, Shanghai Ocean University, 999 Hucheng Huan Road, Shanghai 201306, China.|Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.
Mingyou
M
Li
Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.
Feng
F
Zhu
Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.
Zhendong
Z
Li
Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.|Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, Singapore 138669, Singapore.
Ni
N
Hong
Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.
Yunhan
Y
Hong
D000818:Animals; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism*; D009990:Oryzias / Q000196:embryology* / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D029941:Fish Proteins; D016601:RNA-Binding Proteins