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Convergent evolution of germ granule nucleators: A hypothesis
Arpita Kulkarni1, Cassandra G Extavour2
1Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA.
Stem Cell Research
|August 13, 2017
Summary
Germ cells are the ultimate stem cells, forming germ plasm and germ granules. Research suggests specific genes may have convergently evolved to initiate germ granule assembly across animal lineages.
Area of Science:
- Developmental Biology
- Cell Biology
- Genetics
Background:
- Germ cells are considered "the ultimate stem cells" due to their totipotency.
- Specialized cytoplasm (germ plasm) and ribonucleoprotein (RNP) structures (germ granules) in germ cells have been observed since the 1800s.
- Germ plasm and germ granules are crucial for germ line specification in metazoans.
Purpose of the Study:
- To understand the molecular mechanisms underlying germ plasm and germ granule assembly.
- To investigate the role of lineage-specific genes in initiating germ granule formation.
- To explore the evolutionary convergence of nucleator genes in germ cell development.
Main Methods:
- Literature review of over 100 years of research on germ plasm and germ granules.
- Analysis of studies identifying lineage-specific genes involved in germ granule nucleation.
- Comparative genomics and evolutionary analysis to assess gene convergence.
Main Results:
- Identification of a small set of lineage-specific genes whose products initiate germ granule and/or germ plasm assembly.
- Evidence supporting the hypothesis that these nucleator genes have evolved convergently.
- Demonstration of analogous roles of these genes across diverse animal lineages.
Conclusions:
- The molecular mechanisms of germ plasm and germ granule assembly are beginning to be elucidated.
- Convergent evolution likely played a role in the development of conserved gene functions for germ line specification.
- Further research into these nucleator genes will enhance understanding of fundamental biological processes.
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