BRAENDLE

Christian BRAENDLE

Gene-environment interactions in development and evolution

Main interests

  • Phenotypic plasticity, genotype-by-environment interactions and genetic assimilation
  • Genotype-phenotype map: from developmental variation to life history variation
  • Evolution and ecology of Caenorhabditis nematodes

Scientific Questions

Environmental variation is a key force shaping the function and evolution of developmental mechanisms. Therefore, it is essential to understand how environmental variation modulates developmental processes and resulting phenotypic variation. Much of our research therefore addresses the questions of how developmental systems respond to environmental variation and how such responses evolve. Using the nematode Caenorhabditis elegans and related species, we aim to answer four main questions: How does development integrate variable environmental information to alter phenotypic outcomes? How do developmental responses to environmental variation evolve? How do quantiative developmental traits evolve within species? What are developmental changes underlying adaptive evolution of life histories? We investigate these questions by focusing on molecularly well-characterized processes, such as vulval cell fate patterning, germline development and dauer formation.

Our Strategy

Although genotype-by-environment interactions are common and important determinants of phenotypic variation, the mechanisms by which genetic and environmental variation interact to generate trait variation remain poorly understood. Our projects thus aim to characterize the molecular and developmental basis of genotype-by-environment interactions, how such interactions evolve and how they in turn may impact the evolutionary process itself. In our research, we use the nematode Caenorhabditis elegans and related species as model organisms, and we integrate quantitative experimental approaches from developmental and evolutionary genetics.

Research Aims

Phenotypic plasticity, genotype-by-environment interactions and genetic assimilation

We focus on the environmental context-dependence of developmental processes (e.g. germ cell proliferation, gametogenesis, dauer formation) to characterize the molecular basis and evolution of phenotypic plasticity. Primarily, we aim to identify developmental and molecular determinants of natural variation in these phenotypes through a combination of quantitative and developmental genetic approaches.

Genotype-phenotype map: from developmental variation to life history variation

How complex traits, such as life history traits, emerge through developmental integration of numerous gene-environment, gene-gene interactions, and higher-order interactions among cells and tissues, remains largely unknown. We therefore study the nematode hermaphrodite germline to ask how variation in different parameters of this developmental system translates into variation in reproductive life histories.

Evolution and ecology of Caenorhabditis nematodes

Although C. elegans is increasingly being used in evolutionary studies, there is still very little information on its natural history, ecology, phylogenetic context, and the genetic structure of its natural populations. We therefore contribute to current community efforts to sample and characterize natural Caenorhabditis populations to generate a more comprehensive evolutionary ecological context for C. elegans and its close relatives.

Researchers

GIMOND Clotilde

PreDocs

BILLARD DE SAINT LAUMER Bénédicte

Engineers & Technicians

DUVAL Matthieu
FERRARI Céline

 

Recent publications

  1. Frézal, L, Demoinet, E, Braendle, C, Miska, E, Félix, MA. Natural Genetic Variation in a Multigenerational Phenotype in C. elegans. Curr. Biol. 2018;28 (16):2588-2596.e8. doi: 10.1016/j.cub.2018.05.091. PubMed PMID:30078564 .
  2. Grimbert, S, Vargas Velazquez, AM, Braendle, C. Physiological Starvation Promotes Caenorhabditis elegans Vulval Induction. G3 (Bethesda). 2018;8 (9):3069-3081. doi: 10.1534/g3.118.200449. PubMed PMID:30037804 PubMed Central PMC6118308.
  3. Ferrari, C, Salle, R, Callemeyn-Torre, N, Jovelin, R, Cutter, AD, Braendle, C et al.. Ephemeral-habitat colonization and neotropical species richness of Caenorhabditis nematodes. BMC Ecol. 2017;17 (1):43. doi: 10.1186/s12898-017-0150-z. PubMed PMID:29258487 PubMed Central PMC5738176.
  4. Ludewig, AH, Gimond, C, Judkins, JC, Thornton, S, Pulido, DC, Micikas, RJ et al.. Larval crowding accelerates C. elegans development and reduces lifespan. PLoS Genet. 2017;13 (4):e1006717. doi: 10.1371/journal.pgen.1006717. PubMed PMID:28394895 PubMed Central PMC5402976.
  5. Vielle, A, Callemeyn-Torre, N, Gimond, C, Poullet, N, Gray, JC, Cutter, AD et al.. Convergent evolution of sperm gigantism and the developmental origins of sperm size variability in Caenorhabditis nematodes. Evolution. 2016;70 (11):2485-2503. doi: 10.1111/evo.13043. PubMed PMID:27565121 .
  6. Poullet, N, Vielle, A, Gimond, C, Carvalho, S, Teotónio, H, Braendle, C et al.. Complex heterochrony underlies the evolution of Caenorhabditis elegans hermaphrodite sex allocation. Evolution. 2016;70 (10):2357-2369. doi: 10.1111/evo.13032. PubMed PMID:27501095 .
  7. Cook, DE, Zdraljevic, S, Tanny, RE, Seo, B, Riccardi, DD, Noble, LM et al.. The Genetic Basis of Natural Variation in Caenorhabditis elegans Telomere Length. Genetics. 2016;204 (1):371-83. doi: 10.1534/genetics.116.191148. PubMed PMID:27449056 PubMed Central PMC5012401.
  8. Samuel, BS, Rowedder, H, Braendle, C, Félix, MA, Ruvkun, G. Caenorhabditis elegans responses to bacteria from its natural habitats. Proc. Natl. Acad. Sci. U.S.A. 2016;113 (27):E3941-9. doi: 10.1073/pnas.1607183113. PubMed PMID:27317746 PubMed Central PMC4941482.
  9. Grimbert, S, Tietze, K, Barkoulas, M, Sternberg, PW, Félix, MA, Braendle, C et al.. Anchor cell signaling and vulval precursor cell positioning establish a reproducible spatial context during C. elegans vulval induction. Dev. Biol. 2016;416 (1):123-135. doi: 10.1016/j.ydbio.2016.05.036. PubMed PMID:27288708 .
  10. Poullet, N, Vielle, A, Gimond, C, Ferrari, C, Braendle, C. Evolutionarily divergent thermal sensitivity of germline development and fertility in hermaphroditic Caenorhabditis nematodes. Evol. Dev. ;17 (6):380-97. doi: 10.1111/ede.12170. PubMed PMID:26492828 .
  11. Braendle, C, Teotonio, H. Workshop report: Caenorhabditis nematodes as model organisms to study trait variation and its evolution. Worm. ;4 (2):e1021109. doi: 10.1080/21624054.2015.1021109. PubMed PMID:26430562 PubMed Central PMC4588542.
  12. Poullet, N, Braendle, C. Sampling and Isolation of C. elegans from the Natural Habitat. Methods Mol. Biol. 2015;1327 :221-9. doi: 10.1007/978-1-4939-2842-2_16. PubMed PMID:26423978 .
  13. Grimbert, S, Braendle, C. Cryptic genetic variation uncovers evolution of environmentally sensitive parameters in Caenorhabditis vulval development. Evol. Dev. 2014;16 (5):278-91. doi: 10.1111/ede.12091. PubMed PMID:25143152 .
  14. Félix, MA, Braendle, C, Cutter, AD. A streamlined system for species diagnosis in Caenorhabditis (Nematoda: Rhabditidae) with name designations for 15 distinct biological species. PLoS ONE. 2014;9 (4):e94723. doi: 10.1371/journal.pone.0094723. PubMed PMID:24727800 PubMed Central PMC3984244.
  15. Gimond, C, Jovelin, R, Han, S, Ferrari, C, Cutter, AD, Braendle, C et al.. Outbreeding depression with low genetic variation in selfing Caenorhabditis nematodes. Evolution. 2013;67 (11):3087-101. doi: 10.1111/evo.12203. PubMed PMID:24151995 .
  16. Félix, MA, Jovelin, R, Ferrari, C, Han, S, Cho, YR, Andersen, EC et al.. Species richness, distribution and genetic diversity of Caenorhabditis nematodes in a remote tropical rainforest. BMC Evol. Biol. 2013;13 :10. doi: 10.1186/1471-2148-13-10. PubMed PMID:23311925 PubMed Central PMC3556333.
  17. Braendle, C. Pheromones: evolving language of chemical communication in nematodes. Curr. Biol. 2012;22 (9):R294-6. doi: 10.1016/j.cub.2012.03.035. PubMed PMID:22575463 .
  18. Kiontke, KC, Félix, MA, Ailion, M, Rockman, MV, Braendle, C, Pénigault, JB et al.. A phylogeny and molecular barcodes for Caenorhabditis, with numerous new species from rotting fruits. BMC Evol. Biol. 2011;11 :339. doi: 10.1186/1471-2148-11-339. PubMed PMID:22103856 PubMed Central PMC3277298.
  19. Félix, MA, Braendle, C. The natural history of Caenorhabditis elegans. Curr. Biol. 2010;20 (22):R965-9. doi: 10.1016/j.cub.2010.09.050. PubMed PMID:21093785 .
  20. Braendle, C, Baer, CF, Félix, MA. Bias and evolution of the mutationally accessible phenotypic space in a developmental system. PLoS Genet. 2010;6 (3):e1000877. doi: 10.1371/journal.pgen.1000877. PubMed PMID:20300655 PubMed Central PMC2837400.
Search PubMed

PhD position: Evolutionary Genetics of Development

A PhD position is available in the context of a research project between the laboratory of Christian Braendle (Institut de Biologie Valrose, Nice; http://www.braendlelab.net) and Henrique Teotonio (Institut de Biologie, Ecole Normale Superieure, Paris; http://www.ibens.ens.fr/spip.php?rubrique28&lang=en)

The project will characterize the effects of different breeding systems on the evolution of C. elegans hermaphrodite germline development. The key objectives are (1) to perform experimental evolution under different sex ratios of males, females and hermaphrodites; (2) to characterize the genetic basis of hermaphrodite germline traits through genetic transformation methods and a genome-wide association study; and (3) to determine how natural selection at candidate loci depends on hermaphrodite germline developmental evolution.

The candidate should have a Master’s degree in evolutionary biology and an understanding of the fundamental problems of quantitative genetics, population genetics and developmental genetics, including QTL and GWAS mapping. Candidates with experience in computer programming, experimental evolution, developmental phenotyping and statistical analysis of large data sets are preferred. The PhD student will be expected to conduct full-time independent research in the Braendle lab.

The PhD position is funded by the National Agency of French Research (ANR) for three years, subject to an initial evaluation after 6 months, with a potential one-year extension.
The starting date is flexible.

To apply, send a CV, a letter of motivation, and the contact information for two referees as a single PDF file to Christian Braendle (braendle@unice.fr). Informal inquiries are welcome.

For relevant background information see:
Carvalho et al. 2014. http://doi.org/10.1186/1471-2148-14-117
Poullet et al. 2016. http://doi.org/10.1111/evo.13032
Noble et al. 2017. http://doi.org/10.1534/genetics.117.300406
Teotonio et al. 2017. http://doi.org/10.1534/genetics.115.186288

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PhD position: The role of developmental genetic architecture in shaping evolutionary trends

A PhD position is available in the context of a research project between the laboratory of Christian Braendle (Institut de Biologie Valrose, Nice; http://www.braendlelab.net) and Marie-Anne Félix (Institut de Biologie, Ecole Normale Superieure, Paris; http://www.ibens.ens.fr/spip.php?rubrique29&lang=en).

Project description
Mutation is the ultimate source that generates phenotypic variation. Random mutation, however, does not translate into random phenotypic variation because development limits or biases the mutationally inducible phenotypic spectrum. Hence, the mutationally inducible phenotypic spectrum is fundamental in determining the potential phenotypic trajectories that can be explored by evolution. Whether and how such biases in the introduction of phenotypic variation may influence evolutionary trends – particular directions of evolutionary variation in the phenotypic space – remains extremely poorly understood. In the proposed project, we aim to generate comprehensive empirical insights into the nature and evolution of mutational variance of a developmental system.
This project will therefore investigate how developmental architecture may limit or bias the phenotypic spectrum obtained after random mutation. Whether such biases in the production of phenotypic variation may influence evolutionary trends is poorly understood. Here we address this problem using random mutation lines to explore whether differential mutational sensitivity of developmental cell fates can explain divergent evolutionary patterns in the fates of different homologous vulval precursor cells in two clades of nematodes. This project will (1) quantify mutability of these cell fates in wild isolates of Caenorhabditis and Oscheius, (2) connect these experimental data with patterns of evolutionary variation in these traits in the two genera, and (3) characterize the developmental genetic basis for this differential mutability. The results will be among the first to causally connect mutability, developmental biology and evolutionary trends. This approach is unique as it integrates molecular and evolutionary genetic analysis at the single-cell level.

The candidate should have a Master’s degree in evolutionary or developmental biology and an understanding of the fundamental problems of quantitative and developmental genetics. The PhD student will be expected to conduct full-time independent research in the Braendle lab.

The PhD position is funded by the National Agency of French Research (ANR) for three years, subject to an initial evaluation after 6 months, with a potential one-year extension. The starting date is flexible.

To apply, send a CV, a letter of motivation, and the contact information for two referees as a single PDF file to Christian Braendle (braendle@unice.fr). Informal inquiries are welcome.

For relevant background information see:
Braendle et al. 2010. https://doi.org/10.1371/journal.pgen.1000877
Grimbert & Braendle 2014. https://doi.org/10.1111/ede.12091
Félix & Barkoulas 2015. https://doi.org/10.1038/nrg3949
Besnard et al. 2017. https://doi.org/10.1534/genetics.117.203521

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Two PhD positions: Evolutionary Genetics of Development

Second call: April 6, 2018

Two PhO positions are available in the context of a research project between the laboratories of Henrique Teotonio (Institut de Biologie, Ecole Normale Superieure, Paris; http://www.ibens.ens.fr/spip.php?rubrique28&lang=en) and Christian Braendle (Institut de Biologie Valrose, Nice; http://www.braendlelab.net).

The project will characterize the effects of different breeding systems on the evolution of C. elegans hermaphrodite germline development. The key objectives are (1) to perform experimental evolution under different sex ratios of males, females and hermaphrodites; (2) to characterize the genetic basis of hermaphrodite germline traits through genetic transformation methods and a
genome-wide association study; and (3) to determine how natural selection at candidate loci depends on hermaphrodite germline developmental evolution.

Candidates are expected to have a master’s degree in evotutionary biology and an understanding of the fundamental problems of quantitative genetics, population genetics and developmental genetics, including QTL and GWAS mapping. Candidates with experience in computer programming, experimental evolution, developmental phenotyping and statistical analysis of large data sets are preferred. The PhD students will be expected to conduct full-time independent research in both the Teotonio and Braendle labs.

The PhO positions are funded by the National Agency of French Research (ANR) for three years, subject to an initial evaluation after 6 months, with a potential one-year extension. Successful applicants can start their PhD in summer-fall 2018.

To apply, send a CV, a letter of motivation, and the contact information for two referees as a single PDF file to Henrique Teotonio (teotonio@biologie.ens.fr) and Christian Braendle (braendle@unice.fr), with subject PhD_ANR. Informal inquiries are welcome.

For relevant background information see:
Carvalho et al. 2014. http://doi.org/10.1186/1471-2148-14-117
Poullet et al. 2016. http://doi.org/10.1111/evo.13032
Noble et al. 2017. http://doi.org/10.1534/genetics.117.300406
Teolonio et al. 2017. http://doi.org/10.1534/genetics.115.186288

2012 - Fellow at the Institute for Advanced Study, Berlin

2010 - Schlumberger Award

2008 - ATIP, CNRS

1995 - Fund for Young Talented People, Swiss Study Foundation

1994 - Winner of highest award in the Swiss science contest for young people “Schweizer Jugend Forscht”

iBV - Institut de Biologie Valrose

"Sciences Naturelles"

Université Nice Sophia Antipolis
Faculté des Sciences
Parc Valrose
06108 Nice cedex 2