Hassan Salem

Animal-Microbe Interactions

Max Planck Institute for Biology Tübingen
IMPRS faculty

Hassan has moved to the the John Innes Centre in Norwich, UK and is no longer recruiting students through the IMPRS

Vita

PhD, MPI for Chemical Ecology, Jena (2014)
Humboldt Postdoctoral Fellow, Emory University, Atlanta (2015-2018)
Smithsonian Postdoctoral Fellow, NMNH, Washington D.C. (2018-2020)
Max Planck Research Group Leader at the MPI for Biology Tübingen (Since 2020)

Research Interest

Numerous adaptations in animals are a direct consequence of symbiosis with microbes. We are interested in the molecular currencies driving the cooperation of species, and the genomic and metabolic consequences of coevolution between a host and its symbiont. Our emphasis is on the dynamic relationships that have evolved within leaf-feeding animals, focusing mainly on insects. We use leaf beetles (Coleoptera: Chrysomelidae) as a study system given the streamlined mutualisms they form with specialized symbionts possessing drastically reduced genomes and correspondingly limited metabolisms. These symbioses are defined by the pectin-degrading abilities of the microbe, allowing the insect host to consume, process and subsist on carbohydrate-rich leaves as a sole nutritional resource.
The widespread and convergent evolution of pectinolytic mutualisms in leaf beetles provides a highly tractable model to characterize the molecular and biochemical currencies contributing to the evolution of folivory across the Metazoa. Our work is integrative in nature, combining genomics and fieldwork with chemical ecology and developmental biology to understand the origin and molecular evolution of obligate symbioses.

A green tortoise leaf beetle Cassida rubiginosa sitting on a leaf. — Figure 1. The tortoise leaf beetle *Cassida rubiginosa*

Figure 1. The tortoise leaf beetle *Cassida rubiginosa*

Florescence in situ hybridization micrograph illustrating the localization of pectinolytic symbionts within the symbiotic organ of Conistra rubiginosa. — Figure 2. Florescence in situ hybridization micrograph illustrating the localization of pectinolytic symbionts (green) within the symbiotic organ of *C. rubiginosa*

Figure 2. Florescence in situ hybridization micrograph illustrating the localization of pectinolytic symbionts (green) within the symbiotic organ of *C. rubiginosa*

Available PhD Projects

Hassan Salem has moved to the John Innes Centre in Norwich, UK and is no longer recruiting doctoral researchers via the IMPRS from Molecules to Organisms program.

Selected Reading

Berasategui A, Jagdale S and Salem H. (2023). Fusarium phytopathogens as insect mutualists.
PLoS Pathogens. doi: 10.1371/journal.ppat.1011497
Berasategui A, Breitenbach N, García-Lozano M, Pons I, Sailer B, Lanz C, Rodriguez V, Hipp K, Ziemert N, Windsor D and Salem H. (2022). The leaf beetle Chelymorpha alternans propagates a plant pathogen in exchange for pupal protection. Current Biology. doi: 10.1016/j.cub.2022.07.065
Pons I, Gonzalez M, Breitenbach N, Berger J, Hipp K and Salem H. (2022). For the road: Calibrated maternal investment in light of extracellular symbiont transmission. Proceedings of the Royal Society – Biological Science. doi: 10.1098/rspb.2022.0386
Salem H and Kaltenpoth M. (2022). Beetle-bacterial symbioses: Endless forms most functional. Annual Review of Entomology. doi: 10.1146/annurev-ento-061421-063433
Salem H, Kirsch R, Pauchet Y, Berasategui A, Fukumori K, Moriyama M, Cripps M, Windsor D, Fukatsu T and Gerardo NM. (2020). Symbiont Digestive Range Reflects Host Plant Breadth in Herbivorous Beetles. Current Biology. doi: 10.1016/j.cub.2020.05.043
Salem H, Bauer E, Kirsch R, Berasategui A, Cripps M, Weiss B, Koga R, Fukumori K, Vogel H, Fukatsu T and Kaltenpoth M. (2017). Drastic genome reduction in an herbivore’s pectinolytic symbiont. doi: 10.1016/j.cell.2017.10.029