Background/Objectives:
Vasa and
PL10 belong to the DEAD-box protein family, which plays crucial roles in various cellular functions, such as DNA replication, DNA repair, and RNA processing. Additionally, DEAD-box family genes have also been identified as being related to gonadal development in many
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Background/Objectives:
Vasa and
PL10 belong to the DEAD-box protein family, which plays crucial roles in various cellular functions, such as DNA replication, DNA repair, and RNA processing. Additionally, DEAD-box family genes have also been identified as being related to gonadal development in many species. However, the function of
vasa and
PL10 in abalone is poorly understood on a molecular level. Methods: In the present study, we individually isolated and characterized the
vasa and
PL10 orthologs in
Haliotis discus hannai (
Hdh-vasa and
Hdh-PL10). We also characterized the mRNA distributions of
vasa and
PL10 in various tissues from adult organisms and different embryonic developmental stages using real-time PCR (RT-qPCR) techniques. Furthermore, spatial and temporal expression of
Hdh-vasa and
Hdh-PL10 throughout embryonic and larval development was examined by whole-mount in situ hybridization (WMISH). Results: The two predicted amino acid sequences contained all of the conserved motifs characterized by the DEAD-box family. Homology and phylogenetic analyses indicate that they belong to the vasa and PL10 subfamilies. We found that
vasa and
PL10 mRNA were not solely restricted to gonads but were widely expressed in various tissues. WMISH showed that
Hdh-vasa and
Hdh-PL10 largely overlapped, with both being maternally expressed and specifically localized to the micromere lineage cells during early cleavage stages. By the gastrulation stage,
Hdh-vasa were expressed strongly in two bilaterally symmetrical paraxial clusters, but
Hdh-PL10 was dispersed in entire endodermal region. Our results suggest that
Hdh-vasa-expressing cells are located as a subpopulation of undifferentiated multipotent cells that express
Hdh-PL10. As such, we infer that primordial germ cells are specified from these
vasa-expressing cells at some point during development, and inductive signals (epigenesis) play an important role in specifying primordial germ cells (PGCs) in
H. discus hannai. Conclusions: This study provides valuable insights into the molecular characteristics and expression patterns of
Hdh-vasa and
Hdh-PL10, contributing to a better understanding of their roles in germ cell specification and early embryonic development in
H. discus hannai.
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