Biology subjects

Busse, C.

Publications and source records attributed to Busse, C..

3 recordsLinked to original sources

bioRxiv2026

Actin-related protein Alp1 governs malaria parasite motility and transmission

Motility of the malaria-causing parasite Plasmodium is essential for transmission to and from mosquitoes, with the turnover of actin filaments being a central feature of productive cell movement. Actin-related proteins (Arps) are known to play critical roles in motility, trafficking and chromatin remodelling. Here, we show that the actin-like protein 1 (Alp1), an apicomplexan Arp, is essential for Plasmodium ookinete motility and establishing of infection in mosquitoes. We identified an insertion region in subdomain 4 that contributes to Alp1 function in ookinetes and show novel actin filament structures in ookinetes. A combination of gene deletion and actin filament recognizing chromobody expression revealed a role of Alp1 in promoting actin filament turnover in ookinetes. We have thus identified a novel Arp that has evolved a specialist function to regulate actin dynamics, govern malaria parasite motility and facilitate malaria transmission.

cell biology↗

bioRxiv2026

Plasmodium actin-like proteins 3 and 5a are essential for subsequent steps of mosquito infection

Actin superfamily members are critical for the biology of eukaryotes and archaea. Actin-related proteins (Arps) are a subgroup within the actin superfamily and play essential roles in trafficking, replication and motility. The genome of the malaria parasite Plasmodium contains a set of Arps unique to apicomplexans, termed actin-like proteins (Alps). However, the importance and specific roles of many of these Alps in Plasmodium progression are not yet understood. Here, we determined the functional contribution of Plasmodium berghei Alp3 and Alp5a (recently relabelled as Arp3) by generation of knock-out (KO) lines and their subsequent characterisation across different life cycle stages. Deletion of either Alp did not affect blood stage growth, gametogenesis and ookinete gliding motility. However, deletion of Alp5a lead to smaller and fewer oocysts as well as severely impaired sporozoite formation. The Alp3KO line had highly reduced oocyst loads compared to wild-type parasites. This striking decrease was due to impaired ookinete penetration of the mosquito midgut epithelium. Our study shows that both Alp3 and Alp5a are indispensable for Plasmodium transmission at different steps of initial mosquito infection, provides insights into the role of specific unique members of the actin superfamily during parasite progression and the requirements for efficient midgut penetration.

molecular biology↗

bioRxiv2023

A new look at the architecture and dynamics of the Hydra nerve net

The Hydra nervous system is the paradigm of a "simple nerve net". Nerve cells in Hydra, as in many cnidarian polyps, are organized in a nerve net extending throughout the body column. This nerve net is required for control of spontaneous behavior: elimination of nerve cells leads to polyps that do not move and are incapable of capturing and ingesting prey (Campbell, 1976). We have re-examined the structure of the Hydra nerve net by immunostaining fixed polyps with a novel antibody that stains all nerve cells in Hydra. Confocal imaging shows that there are two distinct nerve nets, one in the ectoderm and one in the endoderm, with the unexpected absence of nerve cells in the endoderm of the tentacles. The nerve nets in the ectoderm and endoderm do not contact each other. High-resolution TEM and serial block face SEM show that the nerve nets consist of bundles of parallel overlapping neurites. Results from transgenic lines show that neurite bundles include different neural circuits and hence that neurites in bundles require circuit-specific recognition. Nerve cell-specific innexins indicate that gap junctions can provide this specificity. The occurrence of bundles of neurites supports a model for continuous growth and differentiation of the nerve net by lateral addition of new nerve cells to the existing net. This model was confirmed by tracking newly differentiated nerve cells.

neuroscience↗