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Genetic consequences of programmed genome rearrangement
Jeramiah J Smith1, Carl Baker, Evan E Eichler
1Benaroya Research Institute at Virginia Mason, Seattle, WA 98101, USA. jjsmit3@uky.edu
Current Biology : CB
|July 24, 2012
Summary
Lamprey somatic cells delete ~20% of germline DNA during development. This programmed genome rearrangement ensures germline pluripotency and prevents its misexpression in somatic tissues, safeguarding genome integrity.
Area of Science:
- Developmental Biology
- Genomics
- Evolutionary Biology
Background:
- Lamprey (Petromyzon marinus) exhibit programmed genome rearrangements, deleting ~20% of germline DNA in somatic cells during embryogenesis.
- This germline-soma genomic differentiation is biologically significant due to the germline's roles in meiotic recombination and pluripotency.
- Potential disruption of genome integrity or cell fate specification arises if germline factors are misexpressed in somatic lineages.
Purpose of the Study:
- To develop new genomic and transcriptomic resources for lamprey.
- To identify genes targeted for programmed DNA deletion in somatic cell lineages.
- To investigate the functional roles of somatically deleted genes in germline development and function.
Main Methods:
- Development of novel genomic and transcriptomic resources for lamprey.
- Genome-wide identification of somatically deleted genes.
- Transcriptome sequencing and targeted validation studies.
Main Results:
- Hundreds of genes targeted for programmed deletion from somatic cell lineages were identified.
- Transcriptome data confirmed that somatically deleted genes are involved in adult germline function and primordial germ cell development.
- Functional inference suggests these deleted genes are crucial for germline pluripotency.
Conclusions:
- Programmed genome rearrangement in lamprey serves as a mechanism to segregate pluripotency functions to the germline.
- This process prevents the misexpression of germline-specific genes in somatic tissues.
- This ancient biological strategy ensures germline integrity and prevents potential oncogenesis.
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