Plastid
Apicoplast
Toxoplasma
Maleria
vs
Ophiocordyceps
Yeast-Like Fungal Symbiont
(YLS)
Apicoplast (Parasites): Contains its own circular genome but does not perform photosynthesis. It is essential for essential prokaryotic metabolic pathways, including fatty acid, isoprenoid, iron-sulfur cluster, and heme synthesis.
Evolutionary Origin
Apicoplasts and plant/algal plastids both share an origin from a cyanobacterium (primary endosymbiosis).
..
An apicoplast is a highly reduced, non-photosynthetic plastid organelle found within parasitic protozoa, while a YLS is a distinct, fungal organism living inside the cells of certain insects (like aphids) as a nutritional symbiont.
Key Differences Between Apicoplasts and YLS:
Evolutionary Origin: Apicoplasts originate from the engulfment of a red alga (secondary endosymbiosis). YLS are true fungi that have adopted an endosymbiotic lifestyle within insect cells.
Structure: Apicoplasts are bound by four membranes and have no cell wall. YLS are full fungal cells with a cytoplasm, nucleus, and cell wall.
Genome: Apicoplasts have a tiny, highly reduced, circular plastid genome, lacking many genes (no 5S rRNA). YLS maintain a larger eukaryotic, yeast-like genome.
Function: Apicoplasts are essential for parasite survival, performing specific metabolic functions (fatty acid, isoprenoid, and heme biosynthesis). YLS provide nutrients to their insect host, often filling the role previously held by bacterial symbionts.
Independence: Apicoplasts are semi-autonomous organelles—they cannot exist outside the host cell. YLS are more autonomous than organelles but are generally obligate, having co-evolved with their insect host.
..
Fungi vs Red Algae
Kingdom & Classification: Fungi belong to the Kingdom Fungi (more related to animals). Red algae are classified within the Kingdom Protista (plant-like protists).
Cell Wall Composition: Fungi possess cell walls made primarily of chitin. Red algae have cell walls made of cellulose.
Energy Storage: Fungi store energy as glycogen. Red algae store energy as starch.
Key Similarities:
Both are eukaryotic organisms.
Both can reproduce using spores.
Both can be part of lichens, which are a mutualistic, symbiotic partnership between fungi and algae (or cyanobacteria).
..
Cyanobacteria: Photosynthetic prokaryotes (also known as blue-green algae) that can exist as free-living organisms or as symbiotic partners.
Lichen: A composite organism arising from a mutualistic symbiosis between a fungus (the mycobiont) and a photosynthetic partner (the photobiont), which can be a green alga or a cyanobacterium.
Bryophyte: A group of non-vascular land plants (including mosses, liverworts, and hornworts) that often host symbiotic cyanobacteria to provide fixed nitrogen.
..
Cyanobacteria
Cyanobacterium
Chytridiomycota
Ophiocordycep
Lichen
Bryophyte
..
https://en.wikipedia.org/wiki/Chytridiomycota
Chytrid
Chytridiomycota
Chytridiomycete
Pseudofungi
Hyphochytriomycete
Mastigomycotina
Spizellomycetales
Phycomycetes
Protoctista
Oomycete
..
Bryophytes and the symbiotic microorganisms, the pioneers of vegetation restoration in karst rocky desertification areas in southwestern China
https://pmc.ncbi.nlm.nih.gov/articles/PMC6943408/
..
Cordyceps
Ophiocordyceps
Ascomycota
Entomopathogen
Endoparasitoid
Sordariomycetes
Hypocreales
Cordyceps Militaris
Cordyceps and Ophiocordyceps are genera of entomopathogenic fungi in the Ascomycota division.
..
Cyanobacteria
Ascomycota
Chimerism
Horizontal Gene Transfer
Virus-Mediated Transfer
Plasmids
Transposons
Horizontal Gene Transfer (HGT) is a major evolutionary mechanism driving genomic diversity in both Cyanobacteria (prokaryotic phototrophs) and Ascomycota (fungi), often mediated by mobile genetic elements like plasmids and transposons. These processes, along with virus-mediated transfer, contribute to chimerism, where organisms possess genetic material from diverse lineages, allowing rapid adaptation to new environments, such as antibiotic resistance or new metabolic capabilities.
Chimerism and Evolution: HGT acts as a "pipeline" of genetic information, creating chimeric genomes where, for example, fungi acquire bacterial genes for nutrient acquisition or metabolic flexibility.
The interplay between Cyanobacteria and Ascomycota, facilitated by mobile elements and viral agents, highlights that HGT is a dynamic force enabling organisms to "steal" advantageous genes from their neighbors, leading to complex, chimeric genomes.