Biology subjects

Blattner, L. A.

Publications and source records attributed to Blattner, L. A..

2 recordsLinked to original sources

bioRxiv2024

Methanotrophic flexibility of Ca. Methanoperedens and its interactions with sulfate-1 reducing bacteria in the sediment of meromictic Lake Cadagno

The greenhouse gas methane is an important contributor to global warming, with freshwater sediments representing important potential methane sources. Anaerobic methane-oxidizing archaea mitigate methane release into the atmosphere by coupling the oxidation of methane to the reduction of extracellular electron acceptors or through interspecies electron transfer with microbial partners. Understanding their metabolic flexibility and microbial interactions is crucial to assess their role in global methane cycling. Here, we investigated anoxic sediments of the meromictic freshwater Lake Cadagno (Switzerland), where Ca. Methanoperedens and sulfate-reducing bacteria co-occur, with metagenomics and long-term incubations. Incubations were performed with different electron acceptors, revealing that manganese oxides supported highest CH4 oxidation potential but enriched for Ca. Methanoperedens phylotypes that were hardly present in the inoculum. Combining data from the inoculum and incubations, we obtained five Ca. Methanoperedens genomes, each harboring different extracellular electron transfer pathways. In a reconstructed Desulfobacterota QYQD01 genome we observed large multi-heme cytochromes, type IV pili, and a putative loss of hydrogenases, suggesting facultative syntrophic interactions with Ca. Methanoperedens. We also screened for putative extrachromosomal elements in the Ca. Methanoperedens genomes, including BORGs. This research deepens our understanding of the metabolic flexibility and potential interspecific interactions of Ca. Methanoperedens in freshwater lakes.

microbiology↗

bioRxiv2023

Chromosome-level assemblies of the Pieris mannii butterfly genome suggest Z-origin and rapid evolution of the W chromosome

The insect order Lepidoptera (butterflies and moth) represents the largest group of organisms with ZW/ZZ sex determination. While the origin of the Z chromosome predates the evolution of the Lepidoptera, the W chromosome is considered younger, but its origin is debated. To shed light on the origin of the lepidopteran W, we here produce chromosome-level genome assemblies for the butterfly Pieris mannii, and compare the sex chromosomes within and between P. mannii and its sister species P. rapae. Our analyses clearly indicate a common origin of the W chromosomes of the two Pieris species, and reveal similarity between the Z and W in chromosome sequence and structure. This supports the view that the W originates from Z-autosome fusion rather than from a redundant B chromosome. We further demonstrate the extremely rapid evolution of the W relative to the other chromosomes and argue that this may preclude reliable conclusions about the origin of the W based on comparisons among distantly related Lepidoptera. Finally, we find that sequence similarity between the Z and W chromosomes is greatest toward the chromosome ends, perhaps reflecting selection for the maintenance of recognition sites essential to chromosome segregation. Our study highlights the utility of long-read sequencing technology for illuminating chromosome evolution. SignificanceLepidoptera (butterflies and moths) typically exhibit a ZW/ZZ sex determination system, but the origin of the W chromosome is controversial. Based on a chromosome-level reference genome for the Southern Small white butterfly and comparative genomic analyses, we propose that the W chromosome in this group of butterflies derives from the Z chromosome and evolves extremely rapidly.

genomics↗