A crozier is an anatomical feature of many fungi in the phylum Ascomycota that forms at the base of asci and looks like a hook-topped shepherd’s staff or stylized religious crosier.[1][2] Croziers resemble and function similarly to clamp connections on the dikaryotic hyphae of Basidiomycota.
Christian crosier (1260-1286) of the form that is the name-sake of the fungal structure.Two rounds of crozier formation, with establishment of a protruding ascus after karyogamy, meiosis and mitosis occur in the penultimate cell
During initial ascus formation in Ascomycota fruitbodies, the crozier helps to maintain the dikaryotic state of both the ascus itself and of the side branch that will continue propagation of the ascogenous hyphae. The tips of developing asci on these ascogenous hyphae curl over. One haploid nucleus migrates into the curved tip while the other compatible haploid nucleus remains in the penultimate space below the hook. The ascus itself forms as a radiating spur branch at the top of the hook. Each nucleus divides, resulting in the formation of a pair of compatible nuclei, i.e. a dikaryon, in the ascus, which is now the penultimate space. Two sister nuclei remain, one in the basal cell and the other in the crozier tip. The tip of the crozier then fuses with the basal cell and walls itself off from the ascus by the formation of a septum. The nucleus from the crozier migrates into the basal cell where the other nucleus remains, thus maintaining a dikaryotic state. Below the base of the ascus, these nuclei migrate together into a growing side branch which is capable of repeating the ascus-crozier formation process indefinitely. Mature croziers are detectable through microscopic examination of mature asci as small, curved bridges at the basal septa. A significant minority of Ascomycota lack croziers, hence the presence or absence of croziers is an important taxonomic character.[citation needed]
Referencesedit
^Tang, Alvin M. C.; Jeewon, Rajesh; Hyde, Kevin D. (2007-05-01). "Phylogenetic utility of protein (RPB2, β-tubulin) and ribosomal (LSU, SSU) gene sequences in the systematics of Sordariomycetes (Ascomycota, Fungi)". Antonie van Leeuwenhoek. 91 (4): 327–349. doi:10.1007/s10482-006-9120-8. ISSN 1572-9699. PMID 17072532. S2CID 12771427.
^Bennett, Richard J.; Turgeon, B. Gillian (2016-10-14). Heitman, Joseph (ed.). "Fungal Sex: The Ascomycota". Microbiology Spectrum. 4 (5): 4.5.20. doi:10.1128/microbiolspec.FUNK-0005-2016. ISSN 2165-0497. PMID 27763253.
External linksedit
January 01, 1970
crozier, mycology, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, crozier, mycology, news, newspapers, books, schol. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Crozier mycology news newspapers books scholar JSTOR February 2024 Learn how and when to remove this message A crozier is an anatomical feature of many fungi in the phylum Ascomycota that forms at the base of asci and looks like a hook topped shepherd s staff or stylized religious crosier 1 2 Croziers resemble and function similarly to clamp connections on the dikaryotic hyphae of Basidiomycota Christian crosier 1260 1286 of the form that is the name sake of the fungal structure Two rounds of crozier formation with establishment of a protruding ascus after karyogamy meiosis and mitosis occur in the penultimate cell During initial ascus formation in Ascomycota fruitbodies the crozier helps to maintain the dikaryotic state of both the ascus itself and of the side branch that will continue propagation of the ascogenous hyphae The tips of developing asci on these ascogenous hyphae curl over One haploid nucleus migrates into the curved tip while the other compatible haploid nucleus remains in the penultimate space below the hook The ascus itself forms as a radiating spur branch at the top of the hook Each nucleus divides resulting in the formation of a pair of compatible nuclei i e a dikaryon in the ascus which is now the penultimate space Two sister nuclei remain one in the basal cell and the other in the crozier tip The tip of the crozier then fuses with the basal cell and walls itself off from the ascus by the formation of a septum The nucleus from the crozier migrates into the basal cell where the other nucleus remains thus maintaining a dikaryotic state Below the base of the ascus these nuclei migrate together into a growing side branch which is capable of repeating the ascus crozier formation process indefinitely Mature croziers are detectable through microscopic examination of mature asci as small curved bridges at the basal septa A significant minority of Ascomycota lack croziers hence the presence or absence of croziers is an important taxonomic character citation needed References edit Tang Alvin M C Jeewon Rajesh Hyde Kevin D 2007 05 01 Phylogenetic utility of protein RPB2 b tubulin and ribosomal LSU SSU gene sequences in the systematics of Sordariomycetes Ascomycota Fungi Antonie van Leeuwenhoek 91 4 327 349 doi 10 1007 s10482 006 9120 8 ISSN 1572 9699 PMID 17072532 S2CID 12771427 Bennett Richard J Turgeon B Gillian 2016 10 14 Heitman Joseph ed Fungal Sex The Ascomycota Microbiology Spectrum 4 5 4 5 20 doi 10 1128 microbiolspec FUNK 0005 2016 ISSN 2165 0497 PMID 27763253 External links editMycology glossary sketch of crozier Glossary sketch of crozier click on eye image next to crozier Retrieved from https en wikipedia org w index php title Crozier mycology amp oldid 1203762998, wikipedia, wiki, book, books, library,
