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70-505: CYL can refer to: Cylindrospermopsin , a cyanotoxin produced by a variety of freshwater cyanobacteria Leung Chun-ying , Chinese politician from Hong Kong Communist Youth League of China , the youth wing of the Chinese Communist Party Wawrzyniec Cyl , a Polish footballer See also [ edit ] Cyl (disambiguation) CYN Topics referred to by

140-571: A and b . Their chloroplasts are surrounded by four and three membranes, respectively, and were probably retained from ingested green algae. Chlorarachniophytes , which belong to the phylum Cercozoa , contain a small nucleomorph , which is a relict of the algae's nucleus . Euglenids , which belong to the phylum Euglenozoa , live primarily in fresh water and have chloroplasts with only three membranes. The endosymbiotic green algae may have been acquired through myzocytosis rather than phagocytosis . (Another group with green algae endosymbionts

210-408: A and c , and phycobilins. The shape can vary; they may be of discoid, plate-like, reticulate, cup-shaped, spiral, or ribbon shaped. They have one or more pyrenoids to preserve protein and starch. The latter chlorophyll type is not known from any prokaryotes or primary chloroplasts, but genetic similarities with red algae suggest a relationship there. In the first three of these groups ( Chromista ),

280-528: A polyphyletic group since they do not include a common ancestor , and although their chlorophyll -bearing plastids seem to have a single origin (from symbiogenesis with cyanobacteria ), they were acquired in different ways. Green algae are a prominent examples of algae that have primary chloroplasts derived from endosymbiont cyanobacteria. Diatoms and brown algae are examples of algae with secondary chloroplasts derived from endosymbiotic red algae , which they acquired via phagocytosis . Algae exhibit

350-413: A farm in northwest Queensland. A nearby dam containing an algal bloom was tested, and C. raciborskii was identified. Analysis by HPLC / mass spectrometry revealed the presence of CYN in a sample of the biomass . An autopsy of one of the calves reported a swollen liver and gall bladder , along with haemorrhages of the heart and small intestine . Histological examination of the hepatic tissue

420-539: A form and capabilities not possessed by the symbiont species alone (they can be experimentally isolated). The photobiont possibly triggers otherwise latent genes in the mycobiont. Trentepohlia is an example of a common green alga genus worldwide that can grow on its own or be lichenised. Lichen thus share some of the habitat and often similar appearance with specialized species of algae ( aerophytes ) growing on exposed surfaces such as tree trunks and rocks and sometimes discoloring them. Coral reefs are accumulated from

490-592: A lineage that eventually led to the higher land plants. The innovation that defines these nonalgal plants is the presence of female reproductive organs with protective cell layers that protect the zygote and developing embryo. Hence, the land plants are referred to as the Embryophytes . The term algal turf is commonly used but poorly defined. Algal turfs are thick, carpet-like beds of seaweed that retain sediment and compete with foundation species like corals and kelps , and they are usually less than 15 cm tall. Such

560-513: A metabolite) acts on either the spindle or centromeres during cell division , inducing loss of whole chromosomes . The uracil group of CYN has been identified as a pharmacophore of the toxin. In two experiments, the vinylic hydrogen atom on the uracil ring was replaced with a chlorine atom to form 5-chlorocylindrospermopsin, and the uracil group was truncated to a carboxylic acid , to form cylindrospermic acid (Figure 6). Both products were assessed as being non-toxic , even at 50 times

630-514: A non-lethal dose. An initial estimate of the toxicity of CYN in 1985 was that an LD 50 at 24 hours was 64±5 mg of freeze-dried culture/kg of mouse body weight on intraperitoneal injection . A further experiment in 1997 measured the LD 50 as 52 mg/kg at 24 hours and 32 mg/kg at 7 days, however the data suggested that another toxic compound was present in the isolate of sonicated cells used; predictions made by Ohtani et al. about

700-478: A red dye derived from it. The Latinization, fūcus , meant primarily the cosmetic rouge. The etymology is uncertain, but a strong candidate has long been some word related to the Biblical פוך ( pūk ), 'paint' (if not that word itself), a cosmetic eye-shadow used by the ancient Egyptians and other inhabitants of the eastern Mediterranean. It could be any color: black, red, green, or blue. The study of algae

770-441: A statistical link to the symptoms. All patients recovered within 4 to 26 days, and at the time there was no apparent cause for the outbreak. Initial thoughts on the cause included poor water quality and diet, however none were conclusive, and the illness was coined the “Palm Island Mystery Disease”. At the time, it was noticed that this outbreak coincided with a severe algal bloom in the local drinking water supply, and soon after

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840-423: A structure (later proven slightly incorrect) was proposed (Figure 1). This almost-correct molecule possesses a tricyclic guanidine group (rings A, B & C), along with a uracil ring (D). The zwitterionic nature of the molecule makes this highly water-soluble, as the presence of charged areas within the molecule creates a dipole effect, suiting the polar solvent . Sensitivity of key signals in

910-463: A turf may consist of one or more species, and will generally cover an area in the order of a square metre or more. Some common characteristics are listed: Many algae, particularly species of the Characeae , have served as model experimental organisms to understand the mechanisms of the water permeability of membranes, osmoregulation , turgor regulation , salt tolerance , cytoplasmic streaming , and

980-989: A wide range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction via spores . Algae lack the various structures that characterize plants (which evolved from freshwater green algae), such as the phyllids (leaf-like structures) and rhizoids of bryophytes ( non-vascular plants ), and the roots , leaves and other xylemic / phloemic organs found in tracheophytes ( vascular plants ). Most algae are autotrophic , although some are mixotrophic , deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy , myzotrophy or phagotrophy . Some unicellular species of green algae, many golden algae , euglenids , dinoflagellates , and other algae have become heterotrophs (also called colorless or apochlorotic algae), sometimes parasitic , relying entirely on external energy sources and have limited or no photosynthetic apparatus. Some other heterotrophic organisms, such as

1050-454: Is an informal term for any organisms of a large and diverse group of photosynthetic eukaryotes , which include species from multiple distinct clades . Such organisms range from unicellular microalgae such as Chlorella , Prototheca and the diatoms , to multicellular macroalgae such as the giant kelp , a large brown alga which may grow up to 50 metres (160 ft) in length. Most algae are aquatic organisms and lack many of

1120-462: Is cytotoxic within 16–18 hours it has been suggested that other mechanisms are the cause of cell death. Cytochrome P450 has been implicated in the toxicity of CYN, as blocking the action of P450 reduces the toxicity of CYN. It has been proposed that an activated P450-derived metabolite (or metabolites) of CYN is the main cause of toxicity. Shaw et al. . demonstrated that the toxin could be metabolised in vivo , resulting in bound metabolites in

1190-453: Is different from Wikidata All article disambiguation pages All disambiguation pages Cylindrospermopsin CYN was first discovered after an outbreak of a mystery disease on Palm Island , Queensland , Australia . The outbreak was traced back to a bloom of Cylindrospermopsis raciborskii in the local drinking water supply, and the toxin was subsequently identified. Analysis of

1260-422: Is its stability . Although the toxin has been found to degrade rapidly in an algal extract when exposed to sunlight , it is resistant to degradation by changes in pH and temperature , and shows no degradation in either the pure solid form or in pure water. As a result, in turbid and unmoving water the toxin can persist for long periods, and although boiling water will kill the cyanobacteria, it may not remove

1330-550: Is most commonly called phycology (from Greek phykos  'seaweed'); the term algology is falling out of use. One definition of algae is that they "have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells ". On the other hand, the colorless Prototheca under Chlorophyta are all devoid of any chlorophyll. Although cyanobacteria are often referred to as "blue-green algae", most authorities exclude all prokaryotes , including cyanobacteria, from

1400-409: Is not conclusively the method of cytotoxicity of the compound. Froscio et al. . proposed that CYN has at least two separate modes of action: the previously reported protein synthesis inhibition, and an as-yet unclear method of causing cell death. It has been shown that cells can survive for long periods (up to 20 hours) with 90% inhibition of protein synthesis, and still maintain viability. Since CYN

1470-536: Is quite different from those of reds and browns, because they have distinct nodes, separated by internode 'stems'; whorls of branches reminiscent of the horsetails occur at the nodes. Conceptacles are another polyphyletic trait; they appear in the coralline algae and the Hildenbrandiales , as well as the browns. Most of the simpler algae are unicellular flagellates or amoeboids , but colonial and nonmotile forms have developed independently among several of

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1540-754: Is related to alterations in the gut microbiome by artificial sweetners. A study including Aspartame conducted at Cedars-Sinai in Los Angeles by Ruchi Mathur, MD detected CYN in the duodenum at levels four times above baseline in Aspartame users, along with alterations in bacterial species. Pathological changes associated with CYN poisoning were reported to be in four distinct stages: inhibition of protein synthesis , proliferation of membranes , lipid accumulation within cells, and finally cell death . Examination of mice livers removed at autopsy showed that on intraperitoneal injection of CYN, after 16 hours ribosomes from

1610-519: Is the Latin word for 'seaweed' and retains that meaning in English. The etymology is obscure. Although some speculate that it is related to Latin algēre , 'be cold', no reason is known to associate seaweed with temperature. A more likely source is alliga , 'binding, entwining'. The Ancient Greek word for 'seaweed' was φῦκος ( phŷkos ), which could mean either the seaweed (probably red algae) or

1680-423: Is the dinoflagellate genus Lepidodinium , which has replaced its original endosymbiont of red algal origin with one of green algal origin. A nucleomorph is present, and the host genome still have several red algal genes acquired through endosymbiotic gene transfer. Also the euglenid and chlorarachniophyte genome contain genes of apparent red algal ancestry) These groups have chloroplasts containing chlorophylls

1750-732: The Calymmian period , early in Boring Billion , but it is difficult to track the key events because of so much time gap. Primary symbiogenesis gave rise to three divisions of archaeplastids , namely the Viridiplantae ( green algae and later plants ), Rhodophyta ( red algae ) and Glaucophyta ("grey algae"), whose plastids further spread into other protist lineages through eukaryote-eukaryote predation , engulfments and subsequent endosymbioses (secondary and tertiary symbiogenesis). This process of serial cell "capture" and "enslavement" explains

1820-609: The Infusoria (microscopic organisms). Unlike macroalgae , which were clearly viewed as plants, microalgae were frequently considered animals because they are often motile. Even the nonmotile (coccoid) microalgae were sometimes merely seen as stages of the lifecycle of plants, macroalgae, or animals. Although used as a taxonomic category in some pre-Darwinian classifications, e.g., Linnaeus (1753), de Jussieu (1789), Lamouroux (1813), Harvey (1836), Horaninow (1843), Agassiz (1859), Wilson & Cassin (1864), in further classifications,

1890-588: The International Association for Lichenology to be "an association of a fungus and a photosynthetic symbiont resulting in a stable vegetative body having a specific structure". The fungi, or mycobionts, are mainly from the Ascomycota with a few from the Basidiomycota . In nature, they do not occur separate from lichens. It is unknown when they began to associate. One or more mycobiont associates with

1960-582: The Late Cambrian / Early Ordovician period, from sessile shallow freshwater charophyte algae much like Chara , which likely got stranded ashore when riverine / lacustrine water levels dropped during dry seasons . These charophyte algae probably already developed filamentous thalli and holdfasts that superficially resembled plant stems and roots , and probably had an isomorphic alternation of generations . They perhaps evolved some 850 mya and might even be as early as 1  Gya during

2030-976: The Vindhya basin have been dated to 1.6 to 1.7 billion years ago. Because of the wide range of algae types, they have increasingly different industrial and traditional applications in human society. Traditional seaweed farming practices have existed for thousands of years and have strong traditions in East Asia food cultures. More modern algaculture applications extend the food traditions for other applications, including cattle feed, using algae for bioremediation or pollution control, transforming sunlight into algae fuels or other chemicals used in industrial processes, and in medical and scientific applications. A 2020 review found that these applications of algae could play an important role in carbon sequestration to mitigate climate change while providing lucrative value-added products for global economies. The singular alga

2100-601: The apicomplexans are also parasites derived from ancestors that possessed plastids, but are not included in any group traditionally seen as algae. Algae are polyphyletic thus their origin cannot be traced back to single hypothetical common ancestor . It is thought that they came into existence when photosynthetic coccoid cyanobacteria got phagocytized by a unicellular heterotrophic eukaryote (a protist ), giving rise to double-membranous primary plastids . Such symbiogenic events (primary symbiogenesis) are believed to have occurred more than 1.5 billion years ago during

2170-435: The apicomplexans , are also derived from cells whose ancestors possessed chlorophyllic plastids, but are not traditionally considered as algae. Algae have photosynthetic machinery ultimately derived from cyanobacteria that produce oxygen as a byproduct of splitting water molecules , unlike other organisms that conduct anoxygenic photosynthesis such as purple and green sulfur bacteria . Fossilized filamentous algae from

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2240-545: The calcareous exoskeletons of marine invertebrates of the order Scleractinia (stony corals ). These animals metabolize sugar and oxygen to obtain energy for their cell-building processes, including secretion of the exoskeleton, with water and carbon dioxide as byproducts. Dinoflagellates (algal protists) are often endosymbionts in the cells of the coral-forming marine invertebrates, where they accelerate host-cell metabolism by generating sugar and oxygen immediately available through photosynthesis using incident light and

2310-735: The hydroxyl group on the uracil bridge can be considered necessary for toxicity. As yet, the relative toxicities of CYN and epiCYN have not been compared. The cylindrospermopsin biosynthetic gene cluster (BGC) was described from Cylindrospermopsis raciborskii AWT205 in 2008. Since the Palm Island outbreak, several other species of cyanobacteria have been identified as producing CYN: Anabaena bergii , Anabaena lapponica , Aphanizomenon ovalisporum , Umezakia natans , Raphidiopsis curvata . and Aphanizomenon issatschenkoi . In Australia, three main toxic cyanobacteria exist: Anabaena circinalis , Microcystis species and C. raciborskii . Of these

2380-419: The rough endoplasmic reticulum (rER) had detached, and at 24 hours, marked proliferation of the membrane systems of the smooth ER and Golgi apparatus had occurred. At 48 hours, small lipid droplets had accumulated in the cell bodies, and at 100 hours, hepatocytes in the hepatic lobules were destroyed beyond function. The process of protein synthesis inhibition has been shown to be irreversible, however

2450-720: The "algae" are seen as an artificial, polyphyletic group. Throughout the 20th century, most classifications treated the following groups as divisions or classes of algae: cyanophytes , rhodophytes , chrysophytes , xanthophytes , bacillariophytes , phaeophytes , pyrrhophytes ( cryptophytes and dinophytes ), euglenophytes , and chlorophytes . Later, many new groups were discovered (e.g., Bolidophyceae ), and others were splintered from older groups: charophytes and glaucophytes (from chlorophytes), many heterokontophytes (e.g., synurophytes from chrysophytes, or eustigmatophytes from xanthophytes), haptophytes (from chrysophytes), and chlorarachniophytes (from xanthophytes). With

2520-639: The 24‑hour toxicity were considerably higher, and it was proposed that another metabolite was present to account for the relatively low 24‑hour toxicity level measured. Because the most likely human route of uptake of CYN is ingestion, oral toxicity experiments were conducted on mice. The oral LD 50 was found to be 4.4-6.9 mg CYN/kg, and in addition to some ulceration of the oesophageal gastric mucosa , symptoms were consistent with that of intraperitoneal dosing. Stomach contents included culture material, which indicated that these LD 50 figures might be overestimated. Another means of exposure to CYN

2590-424: The LD 50 of CYN. In the previous determination of the structure of deoxycylindrospermopsin, a toxicity assessment of the compound was carried out. Mice injected intraperitoneally with four times the 5-day median lethal dose of CYN showed no toxic effects. As this compound was shown to be relatively abundant, it was concluded that this analogue was comparatively non-toxic. Given that both CYN and epiCYN are toxic,

2660-471: The NMR spectrum to small changes in pH suggested that the uracil ring exists in a keto / enol tautomeric relationship, where a hydrogen transfer results in two distinct structures (Figure 2). It was originally proposed that a hydrogen bond between the uracil and guanidine groups in the enol tautomer would make this the dominant form. A second metabolite of C. raciborskii was identified from extracts of

2730-670: The abandonment of plant-animal dichotomous classification, most groups of algae (sometimes all) were included in Protista , later also abandoned in favour of Eukaryota . However, as a legacy of the older plant life scheme, some groups that were also treated as protozoans in the past still have duplicated classifications (see ambiregnal protists ). Some parasitic algae (e.g., the green algae Prototheca and Helicosporidium , parasites of metazoans, or Cephaleuros , parasites of plants) were originally classified as fungi , sporozoans , or protistans of incertae sedis , while others (e.g.,

2800-451: The carbon dioxide produced by the host. Reef-building stony corals ( hermatypic corals ) require endosymbiotic algae from the genus Symbiodinium to be in a healthy condition. The loss of Symbiodinium from the host is known as coral bleaching , a condition which leads to the deterioration of a reef. Endosymbiontic green algae live close to the surface of some sponges, for example, breadcrumb sponges ( Halichondria panicea ). The alga

2870-420: The chloroplast has four membranes, retaining a nucleomorph in cryptomonads , and they likely share a common pigmented ancestor, although other evidence casts doubt on whether the heterokonts , Haptophyta , and cryptomonads are in fact more closely related to each other than to other groups. The typical dinoflagellate chloroplast has three membranes, but considerable diversity exists in chloroplasts within

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2940-624: The composition of the three major groups of algae. Their lineage relationships are shown in the figure in the upper right. Many of these groups contain some members that are no longer photosynthetic. Some retain plastids, but not chloroplasts, while others have lost plastids entirely. Phylogeny based on plastid not nucleocytoplasmic genealogy: Cyanobacteria Glaucophytes Rhodophytes Stramenopiles Cryptophytes Haptophytes Euglenophytes Chlorarachniophytes Chlorophytes Charophytes Land plants (Embryophyta) These groups have green chloroplasts containing chlorophylls

3010-681: The continent are able to synthesize it. In 1979, 138 inhabitants of Palm Island , Queensland , Australia , were admitted to hospital, suffering various symptoms of gastroenteritis . All of these were children; in addition, 10 adults were affected but not hospitalised. Initial symptoms, including abdominal pain and vomiting , resembled those of hepatitis ; later symptoms included kidney failure and bloody diarrhoea . Urine analysis revealed high levels of proteins , ketones and sugar in many patients, along with blood and urobilinogen in lesser numbers. The urine analysis, along with faecal microscopy and poison screening, could not provide

3080-653: The cyanobacteria after the observation of a frequently occurring peak accompanying that of CYN during UV and MS experiments. Analysis by MS and NMR methods concluded that this new compound was missing the oxygen adjacent to the uracil ring, and was named deoxycylindrospermopsin (Figure 3). In 1999, an epimer of CYN, named 7-epicyclindrospermopsin (epiCYN), was also identified as a minor metabolite from Aphanizomenon ovalisporum . This occurred whilst isolating CYN from cyanobacteria taken from Lake Kinneret in Israel . The proposed structure of this molecule differed from CYN only in

3150-436: The definition of algae. The algae contain chloroplasts that are similar in structure to cyanobacteria. Chloroplasts contain circular DNA like that in cyanobacteria and are interpreted as representing reduced endosymbiotic cyanobacteria . However, the exact origin of the chloroplasts is different among separate lineages of algae, reflecting their acquisition during different endosymbiotic events. The table below describes

3220-765: The direct costs incurred totalled more than A$ 1.3 million. Moreover, 2000 site-days of recreation were also lost, and the economic cost was estimated at A$ 10 million, after taking into account indirectly affected industries such as tourism , accommodation and transport . Current methods include liquid chromatography coupled to mass spectrometry ( LC-MS ), mouse bioassay, protein synthesis inhibition assay, and reverse-phase HPLC-PDA (Photo Diode Array) analysis. A cell free protein synthesis assay has been developed which appears to be comparable to HPLC-MS. Alga Algae ( UK : / ˈ æ l ɡ iː / AL -ghee , US : / ˈ æ l dʒ iː / AL -jee ; sg. : alga / ˈ æ l ɡ ə / AL -gə )

3290-493: The distinct cell and tissue types, such as stomata , xylem and phloem that are found in land plants . The largest and most complex marine algae are called seaweeds . In contrast, the most complex freshwater forms are the Charophyta , a division of green algae which includes, for example, Spirogyra and stoneworts . Algae that are carried passively by water are plankton , specifically phytoplankton . Algae constitute

3360-425: The diversity of photosynthetic eukaryotes. Recent genomic and phylogenomic approaches have significantly clarified plastid genome evolution , the horizontal movement of endosymbiont genes to the "host" nuclear genome , and plastid spread throughout the eukaryotic tree of life . Fossils of isolated spores suggest land plants may have been around as long as 475  million years ago (mya) during

3430-432: The first to divide macroscopic algae into four divisions based on their pigmentation. This is the first use of a biochemical criterion in plant systematics. Harvey's four divisions are: red algae (Rhodospermae), brown algae (Melanospermae), green algae (Chlorospermae), and Diatomaceae. At this time, microscopic algae were discovered and reported by a different group of workers (e.g., O. F. Müller and Ehrenberg ) studying

3500-540: The focus turned to the dam in question. An epidemiological study of this “mystery disease” later confirmed that the Solomon Dam was implicated, as those that became ill had used water from the dam. It became apparent that a recent treatment of the algal bloom with copper sulfate caused lysis of the algal cells, releasing a toxin into the water. A study of the dam revealed that periodic blooms of algae were caused predominantly by three strains of cyanobacteria : two of

3570-530: The genera Volvox and Corallina , and a species of Acetabularia (as Madrepora ), among the animals. In 1768, Samuel Gottlieb Gmelin (1744–1774) published the Historia Fucorum , the first work dedicated to marine algae and the first book on marine biology to use the then new binomial nomenclature of Linnaeus. It included elaborate illustrations of seaweed and marine algae on folded leaves. W. H. Harvey (1811–1866) and Lamouroux (1813) were

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3640-446: The generation of action potentials . Plant hormones are found not only in higher plants, but in algae, too. Some species of algae form symbiotic relationships with other organisms. In these symbioses, the algae supply photosynthates (organic substances) to the host organism providing protection to the algal cells. The host organism derives some or all of its energy requirements from the algae. Examples are: Lichens are defined by

3710-462: The genus Anabaena , and Cylindrospermopsis raciborskii , previously unknown in Australian waters. A mouse bioassay of the three demonstrated that although the two Anabaena strains were non-toxic, C. raciborskii was highly toxic. Later isolation of the compound responsible led to the identification of the toxin cylindrospermopsin. A later report alternatively proposed that the excess copper in

3780-538: The green algae Phyllosiphon and Rhodochytrium , parasites of plants, or the red algae Pterocladiophila and Gelidiocolax mammillatus , parasites of other red algae, or the dinoflagellates Oodinium , parasites of fish) had their relationship with algae conjectured early. In other cases, some groups were originally characterized as parasitic algae (e.g., Chlorochytrium ), but later were seen as endophytic algae. Some filamentous bacteria (e.g., Beggiatoa ) were originally seen as algae. Furthermore, groups like

3850-563: The group, and a number of endosymbiotic events apparently occurred. The Apicomplexa , a group of closely related parasites, also have plastids called apicoplasts , which are not photosynthetic, but appear to have a common origin with dinoflagellate chloroplasts. Linnaeus , in Species Plantarum (1753), the starting point for modern botanical nomenclature , recognized 14 genera of algae, of which only four are currently considered among algae. In Systema Naturae , Linnaeus described

3920-453: The groups. Some of the more common organizational levels, more than one of which may occur in the lifecycle of a species, are In three lines, even higher levels of organization have been reached, with full tissue differentiation. These are the brown algae, —some of which may reach 50 m in length ( kelps ) —the red algae, and the green algae. The most complex forms are found among the charophyte algae (see Charales and Charophyta ), in

3990-417: The late phase of the Boring Billion . A range of algal morphologies is exhibited, and convergence of features in unrelated groups is common. The only groups to exhibit three-dimensional multicellular thalli are the reds and browns , and some chlorophytes . Apical growth is constrained to subsets of these groups: the florideophyte reds, various browns, and the charophytes. The form of charophytes

4060-462: The latter, which produces CYN, has attracted considerable attention, not only due to the Palm Island outbreak, but also as the species is spreading to more temperate areas. Previously, the algae was classed as only tropical , however it has recently been discovered in temperate regions of Australia, Europe , North and South America , and also New Zealand . In August 1997, three cows and ten calves died from cylindrospermopsin poisoning on

4130-431: The liver and lungs, along with varying epithelial cell necrosis in areas of the kidneys. A more recent mouse bioassay of the effects of cylindrospermopsin revealed an increase in liver weight, with both lethal and non-lethal doses; in addition the livers appeared dark-coloured. Extensive necrosis of hepatocytes was visible in mice administered a lethal dose, and some localised damage was also observed in mice administered

4200-453: The liver tissue, and that damage was more prevalent in rat hepatocytes than other cell types. Due to the structure of CYN, which includes sulfate , guanidine and uracil groups, it has been suggested that CYN acts on DNA or RNA . Shaw et al. . reported covalent binding of CYN or its metabolites to DNA in mice, and DNA strand breakage has also been observed. Humpage et al. also supported this, and in addition postulated that CYN (or

4270-420: The orientation of the hydroxyl group adjacent to the uracil ring (Figure 4). Synthetic approaches to CYN started with the piperidine ring (A), and progressed to annulation of rings B and C. The first total synthesis of CYN was reported in 2000 through a 20-step process. Improvements to synthetic methods led to a revision of the stereochemistry of CYN in 2001. A synthetic process controlling each of

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4340-405: The same phycobiont species, from the green algae, except that alternatively, the mycobiont may associate with a species of cyanobacteria (hence "photobiont" is the more accurate term). A photobiont may be associated with many different mycobionts or may live independently; accordingly, lichens are named and classified as fungal species. The association is termed a morphogenesis because the lichen has

4410-403: The same term [REDACTED] This disambiguation page lists articles associated with the title CYL . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=CYL&oldid=1082607150 " Category : Disambiguation pages Hidden categories: Short description

4480-411: The six stereogenic centres of epiCYN established that the original assignments of both CYN and epiCYN were in fact a reversal of the correct structures. An alternative approach by White and Hansen supported these absolute configurations (Figure 5). At the time of this correct assignment, it was suggested that the enol form was not dominant. One of the key factors associated with the toxicity of CYN

4550-527: The tissues. Such bioaccumulation , particularly in the aquaculture industry, was of concern, especially when humans were the end users of the product. The impact of cyanobacterial blooms has been assessed in economic terms. In December 1991, the world's largest algal bloom occurred in Australia, where 1000 km of the Darling - Barwon River was affected. One million people-days of drinking water were lost, and

4620-586: The toxin led to a proposed chemical structure in 1992, which was revised after synthesis was achieved in 2000. Several analogues of CYN, both toxic and non-toxic, have been isolated or synthesised. C. raciborskii has been observed mainly in tropical areas, however has also recently been discovered in temperate regions of Australia , North , South America , New Zealand and Europe . However, CYN-producing strain of C. raciborskii has not been identified in Europe, several other cyanobacteria species occurring across

4690-487: The toxin. Hawkins et al. . demonstrated the toxic effects of CYN by mouse bioassay, using an extract of the original Palm Island strain. Acutely poisoned mice displayed anorexia , diarrhoea and gasping respiration . Autopsy results revealed haemorrhages in the lungs , livers , kidneys , small intestines and adrenal glands . Histopathology revealed dose-related necrosis of hepatocytes , lipid accumulation, and fibrin thrombi formation in blood vessels of

4760-415: The water contained both extracellular and intracellular CYN, and that the crayfish had accumulated this primarily in the liver but also in the muscle tissue. Examination of the gut contents revealed cyanobacterial cells , indicating that the crayfish had ingested intracellular toxin. An experiment using an extract of the bloom showed that it was also possible to uptake extracellular toxin directly into

4830-467: The water was the cause of the disease. The excessive dosing was following the use of least-cost contractors to control the algae, who were unqualified in the field. Isolation of the toxin using cyanobacteria cultured from the original Palm Island strain was achieved by gel filtration of an aqueous extract, followed by reverse-phase HPLC . Structure elucidation was achieved via mass spectrometry (MS) and nuclear magnetic resonance (NMR) experiments, and

4900-519: Was consistent with that reported in CYN-affected mice. This was the first report of C. raciborskii causing mortality in animals in Australia. The effect of a bloom of C. raciborskii on an aquaculture pond in Townsville , Australia was assessed in 1997. The pond contained Redclaw crayfish , along with a population of Lake Eacham Rainbowfish to control the excess food. Analysis revealed that

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