About this Research Topic
Germ cells are essential for reproduction and the continuation of species. The formation of germ cells is a highly dynamic process that spans through the animal life cycle. The germline life cycle begins with specification of germ cells in the early embryo and their migration to the forming gonads. Subsequently, gamete differentiation and meiosis in the gonads occurs through puberty, leading to fully differentiated and mature gametes that fuse during fertilization. This infinite cycle ends and is reinitiated by establishing the determinants that specify the germ cells back in the early embryo of the next generation. Each of these steps involves fascinating biological phenomena, but many key open questions regarding their underlying mechanisms still remain poorly understood. Moreover, defects can lead to infertility or tumors.
This versatile nature of germ cell formation throughout the animal life cycle has traditionally presented substantial challenges in their investigation. Understanding the vast number of interrelated molecular, cellular, and developmental processes requires interdisciplinary approaches. The zebrafish has been instrumental in pioneering our mechanistic understanding of many of these processes. Recently, new technological advances in genetics, microscopy, genomics, and single cell technologies have enabled multiple breakthroughs in the field. Examples of these recent advances include new understanding of germ granule segregation in the early embryo, how primordial germ cells sense and find their way during migration, mechanisms of chromosomal pairing and homologous recombination in meiosis and their visualization by live time-lapse microscopy, new interactions between somatic and germ cells in developing gonads, newly identified proteins in mRNP granules of the Balbiani body and their phase separation in early oocytes, how germline stem cells contribute to ovarian regeneration, and new players in gamete fusion during fertilization. In addition, technologies like single cell and spatial genomics, are promising in shedding new light on long standing questions in the field. These discoveries have been accompanied, and some made possible, by a significant growth in the open and collaborative community of zebrafish germ cell researchers.
We aim to solicit submissions describing recently developed methodologies and Review articles in the areas listed below from researchers who are the leaders in their fields, as well as early stage investigators. Our overall goal is to expand the experimental toolbox and breadth of knowledge that will enable new advances in zebrafish germ cell research. Having these articles collected in this Research Topic will make these tools easily accessible. More and more researchers are appreciating the strengths of using zebrafish as a model organism, including senior investigators bringing zebrafish into their established research programs. To this end, Methods papers will be complemented by Review articles that will highlight the biological significance, and future directions of germ cell research.
Topics will include, but are not limited to:
• Primordial germ cell specification and migration
• Germline stem cells
• Gonad development and Sex determination
• mRNP granules and phase-separation in the germline
• Cytoskeleton and polarity in germ cells
• Cross-talk with somatic cells of the gonad
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.