Date of Presentation
5-5-2022 12:00 AM
Embargo Period
11-5-2022
College
School of Osteopathic Medicine
Poster Abstract
The heterochronic pathway of Caenorhabditis elegans is exemplary as a mechanism of developmental timing: mutations in genes of this pathway alter the relative timing of diverse developmental events independent of spatial or cell type specific regulation. It is the most thoroughly characterized developmental timing pathway known. Most of the heterochronic genes are conserved across great evolutionary time, and a few homologs seem to have developmental timing roles in certain contexts. The degree to which other organisms have explicit developmental timing mechanisms, and what factors comprise those mechanisms, isn’t generally known.
Developmental pathways evolve even if the resulting morphology remains the same, a phenomenon called Developmental Systems Drift. Components of developmental pathways and their roles may stay the same over time, their relationships to each other may change, or new factors can join or leave a pathway as it evolves, while still producing the same developmental result. It is known, for example, that the components and relationships of certain spatial patterning pathways are largely conserved widely. But in sex determination, for example, the pathways evolve rapidly and those of even closely related organisms can differ dramatically.
We set out to explore the evolution of this well-characterized developmental timing pathway by characterizing the phenotypes of the heterochronic gene orthologs in a closely related nematode C. briggsae. These species share the same ecological niche and are nearly identical in development and morphology. Both worms develop after hatching through four larval stages (L1-L4) before reaching adulthood. Both develop the egg laying system, including the vulva, during the L3 and L4. Lateral hypodermal cells divide and add nuclei to a syncytium at each larval stage and diffentiate at adulthood producing a cuticle structure called alae, a feature we use to characterize heterochronic mutants.
Keywords
Caenorhabditis elegans, Larva, Phenotype, Mutation, Giant Cells, Developmental Biology
Disciplines
Genetic Processes | Genetic Structures | Laboratory and Basic Science Research | Medical Molecular Biology | Medicine and Health Sciences
Document Type
Poster
Included in
Genetic Processes Commons, Genetic Structures Commons, Laboratory and Basic Science Research Commons, Medical Molecular Biology Commons
Conservation and Divergence in the Heterochronic Pathway of C. elegans and C. briggsae
The heterochronic pathway of Caenorhabditis elegans is exemplary as a mechanism of developmental timing: mutations in genes of this pathway alter the relative timing of diverse developmental events independent of spatial or cell type specific regulation. It is the most thoroughly characterized developmental timing pathway known. Most of the heterochronic genes are conserved across great evolutionary time, and a few homologs seem to have developmental timing roles in certain contexts. The degree to which other organisms have explicit developmental timing mechanisms, and what factors comprise those mechanisms, isn’t generally known.
Developmental pathways evolve even if the resulting morphology remains the same, a phenomenon called Developmental Systems Drift. Components of developmental pathways and their roles may stay the same over time, their relationships to each other may change, or new factors can join or leave a pathway as it evolves, while still producing the same developmental result. It is known, for example, that the components and relationships of certain spatial patterning pathways are largely conserved widely. But in sex determination, for example, the pathways evolve rapidly and those of even closely related organisms can differ dramatically.
We set out to explore the evolution of this well-characterized developmental timing pathway by characterizing the phenotypes of the heterochronic gene orthologs in a closely related nematode C. briggsae. These species share the same ecological niche and are nearly identical in development and morphology. Both worms develop after hatching through four larval stages (L1-L4) before reaching adulthood. Both develop the egg laying system, including the vulva, during the L3 and L4. Lateral hypodermal cells divide and add nuclei to a syncytium at each larval stage and diffentiate at adulthood producing a cuticle structure called alae, a feature we use to characterize heterochronic mutants.