Periodic Reporting for period 1 - ASymbEL (A multilevel approach to address the role of Archaeal Symbionts in the Evolution of Life)
Periodo di rendicontazione: 2021-02-01 al 2022-07-31
Microbial symbioses play an essential role in most aspects of life’s evolution and enabled major evolutionary events such as the origin of eukaryotes. But in spite of the importance of symbioses, our knowledge is based on a limited number of microbial host-symbiont systems, few of which include Archaea. Notably, recent cultivation-independent approaches have revealed two hugely diverse microbial groups of putative deep-branching archaeal and bacterial symbionts referred to as DPANN and CPR, respectively.
The major aims of ASymbEL are to test the hypotheses that (a) DPANN, together with CPR, have key positions in the tree of life, requiring to revise our view on the early evolution of cells and (b) that the diverse DPANN substantially shape the evolution of life through symbiont-host interactions. This will be achieved by integrating knowledge from both micro- and macroevolutionary levels:
In particular, we aim to place the diverse DPANN in a rooted tree of life including CPR, reconcile the history of their genome content evolution and identify novel host-symbiont systems using sophisticated phylogenomic approaches combined with microscopy. Further, we aim to elucidate fundamental principles of the genome evolution of DPANN and for the first time use experimental evolution approaches to study two cultivated DPANN symbionts in co-culture with their hosts. Finally, we aim to determine the dynamics of natural populations of known and newly identified archaeal host-symbiont systems and the influence of symbionts on host population structure and genome evolution using a unique approach combining single-cell, metagenomics and population genomics.
The accurate placement of DPANN in a rooted species trees will be foundational for any hypothesis on the deep origin of cellular life and our understanding of the evolutionary impact of symbioses. Furthermore, the assessment of microevolutionary aspects of genome evolution of DPANN archaea and their role in host diversification and population structure, will allow to provide key insights into the ecological function and evolutionary impact of these these extremely diverse and globally distributed symbionts.
The major aims of ASymbEL are to test the hypotheses that (a) DPANN, together with CPR, have key positions in the tree of life, requiring to revise our view on the early evolution of cells and (b) that the diverse DPANN substantially shape the evolution of life through symbiont-host interactions. This will be achieved by integrating knowledge from both micro- and macroevolutionary levels:
In particular, we aim to place the diverse DPANN in a rooted tree of life including CPR, reconcile the history of their genome content evolution and identify novel host-symbiont systems using sophisticated phylogenomic approaches combined with microscopy. Further, we aim to elucidate fundamental principles of the genome evolution of DPANN and for the first time use experimental evolution approaches to study two cultivated DPANN symbionts in co-culture with their hosts. Finally, we aim to determine the dynamics of natural populations of known and newly identified archaeal host-symbiont systems and the influence of symbionts on host population structure and genome evolution using a unique approach combining single-cell, metagenomics and population genomics.
The accurate placement of DPANN in a rooted species trees will be foundational for any hypothesis on the deep origin of cellular life and our understanding of the evolutionary impact of symbioses. Furthermore, the assessment of microevolutionary aspects of genome evolution of DPANN archaea and their role in host diversification and population structure, will allow to provide key insights into the ecological function and evolutionary impact of these these extremely diverse and globally distributed symbionts.