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54-599: See text Nototheniidae , the notothens or cod icefishes , is a family of ray-finned fishes , part of the suborder Notothenioidei which is traditionally placed within the order Perciformes . They are largely found in the Southern Ocean . Nototheniidae was described as a family in 1861 by the German-born British ichthyologist Albert Günther with the type genus being Notothenia which had been described in 1844 by Sir John Richardson with

108-559: A beta helix that form a flat ice-binding surface. Unlike the other AFPs, there is not a singular sequence motif for the ice-binding site. AFP found from the metagenome of the ciliate Euplotes focardii and psychrophilic bacteria has an efficient ice re-crystallization inhibition ability. 1 μM of Euplotes focardii consortium ice-binding protein ( Efc IBP) is enough for the total inhibition of ice re-crystallization in –7.4 °C temperature. This ice-recrystallization inhibition ability helps bacteria to tolerate ice rather than preventing

162-515: A compressed beta-solenoid (beta sandwich) with four rows of threonine residus, and this AFP is structurally similar to that modelled for the non-homologous AFP from the pale beauty moth. In contrast, the AFP from the spruce budworm moth is a solenoid that superficially resembles the Tenebrio protein, with a similar ice-binding surface, but it has a triangular cross-section, with longer repeats that lack

216-457: A consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called the seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time

270-464: A difference between the melting point and freezing point (busting temperature of AFP bound ice crystal) known as thermal hysteresis. The addition of AFPs at the interface between solid ice and liquid water inhibits the thermodynamically favored growth of the ice crystal. Ice growth is kinetically inhibited by the AFPs covering the water-accessible surfaces of ice. Thermal hysteresis is easily measured in

324-446: A family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching

378-582: A flat, rigid surface in some AFPs seems to facilitate its interaction with ice via Van der Waals force surface complementarity. Normally, ice crystals grown in solution only exhibit the basal (0001) and prism faces (1010), and appear as round and flat discs. However, it appears the presence of AFPs exposes other faces. It now appears the ice surface 2021 is the preferred binding surface, at least for AFP type I. Through studies on type I AFP, ice and AFP were initially thought to interact through hydrogen bonding (Raymond and DeVries, 1977). However, when parts of

432-597: A molecules influence the enhancing ability of DAFP-1. Optimum activity in TH is correlated with high concentration of enhancer molecules. Li et al. 1998 investigated the effects of pH and solute on thermal hysteresis in Antifreeze proteins from Dendrioides canadensis. TH activity of DAFP-4 was not affected by pH unless the there was a low solute concentration (pH 1) in which TH decreased. The effect of five solutes; succinate, citrate, malate, malonate, and acetate, on TH activity

486-408: A non colligative manner. This phenomenon allows them to act as an antifreeze at concentrations 1/300th to 1/500th of those of other dissolved solutes. Their low concentration minimizes their effect on osmotic pressure . The unusual properties of AFPs are attributed to their selective affinity for specific crystalline ice forms and the resulting blockade of the ice-nucleation process. AFPs create

540-547: A recently shared phylogeny. In Herring and smelt, up to 98% of introns for this gene are shared; the method of transfer is assumed to occur during mating via sperm cells exposed to foreign DNA. The direction of transfer is known to be from herring to smelt as herring have 8 times the copies of AFP gene as smelt (1) and the segments of the gene in smelt house transposable elements which are otherwise characteristic of and common in herring but not found in other fishes. There are two reasons why many types of AFPs are able to carry out

594-464: A thaumatin-like protein and polycarboxylates. Modifications of DAFP-1 with the arginine specific reagent resulted in the partial and complete loss of thermal hysteresis in DAFP-1, indicating that arginine plays a crucial role in enhancing its ability. Different enhancer molecules of DAFP-1 have distinct thermal hysteresis activity. Amornwittawat et al. 2008 found that the number of carboxylate groups in

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648-423: Is likely substantial in most northerly and temperate regions already. Given the known historic consumption of AFPs, it is safe to conclude their functional properties do not impart any toxicologic or allergenic effects in humans. As well, the transgenic process of ice structuring proteins production is widely used in society. Insulin and rennet are produced using this technology. The process does not impact

702-762: Is often called a "snow flea", produces hyperactive AFPs. Although they are also repetitive and have a flat ice-binding surface, the similarity ends there. Around 50% of the residues are glycine (Gly), with repeats of Gly-Gly- X or Gly-X-X, where X is any amino acid. Each 3-amino-acid repeat forms one turn of a polyproline type II helix. The helices then fold together, to form a bundle that is two helices thick, with an ice-binding face dominated by small hydrophobic residues like alanine, rather than threonine. Other insects, such as an Alaskan beetle, produce hyperactive antifreezes that are even less similar, as they are polymers of sugars ( xylomannan ) rather than polymers of amino acids (proteins). Taken together, this suggests that most of

756-560: Is referred to as convergent evolution . Evidence for convergent evolution in Northern cod ( Gadidae ) and Notothenioids is supported by the findings of different spacer sequences and different organization of  introns and exons as well as unmatching AFGP tripeptide sequences, which emerged from duplications of short ancestral sequences which were differently permuted (for the same tripeptide) by each group. These groups diverged approximately 7-15 million years ago. Shortly after (5-15 mya),

810-570: Is rounded to forked and the pectoral fins are large. The mouth is terminal and may be horizontal or angled with a protrusible upper jaw. There are no teeth on the roof of the mouth. in most species there are no spines on the preoperculum or operculum . Any scales are usually ctenoid although the spinules may be reduced or absent. They have between 1 and 3 lateral lines . They vary in size from. Total length of 11 cm (4.3 in) in Patagonotothen cornucola to 215 cm (85 in) in

864-644: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Antifreeze glycoprotein Unlike the widely used automotive antifreeze, ethylene glycol , AFPs do not lower freezing point in proportion to concentration. Rather, they work in

918-615: The Monte Carlo method ). According to the structure and function study on the antifreeze protein from Pseudopleuronectes americanus , the antifreeze mechanism of the type-I AFP molecule was shown to be due to the binding to an ice nucleation structure in a zipper-like fashion through hydrogen bonding of the hydroxyl groups of its four Thr residues to the oxygens along the [ 01 1 ¯ 2 ] {\displaystyle [01{\overline {1}}2]} direction in ice lattice, subsequently stopping or retarding

972-606: The Patagonian toothfish ( Dissostichus eleginoides ). Nototheniidae species are largely found in the Southern Ocean and are particularly abundant off the shores of Antarctica . As the dominant Antarctic fish taxa, they occupy both sea-bottom and water-column ecological niches. Nototheniidae is a family of teleost fishes found mainly in the Southern Ocean, surrounding the continent of Antarctica. The family comprises about 50 species of fish that are adapted to living in

1026-585: The efcIBP gene was inserted to E. coli genome. Efc IBP has a typical AFP structure consisting of multiple beta-sheets and an alpha-helix . Also, all the ice-binding polar residues are at the same site of the protein. The remarkable diversity and distribution of AFPs suggest the different types evolved recently in response to sea level glaciation occurring 1–2 million years ago in the Northern hemisphere and 10-30 million years ago in Antarctica. Data collected from deep sea ocean drilling has revealed that

1080-742: The AFGP gene evolved from an ancestral pancreatic trypsinogen gene in Notothenioids. AFGP and trypsinogen genes split via a sequence divergence - an adaptation which occurred alongside the cooling and eventual freezing of the Antarctic Ocean. The evolution of the AFGP gene in Northern cod occurred more recently (~3.2 mya) and emerged from a noncoding sequence via tandem duplications in a Thr-Ala-Ala unit. Antarctic notothenioid fish and arctic cod, Boreogadus saida , are part of two distinct orders and have very similar antifreeze glycoproteins. Although

1134-549: The AFP function may be overcome at extremely cold temperatures, leading to rapid ice growth and death. Freeze tolerant : These species are able to survive body fluid freezing. Some freeze tolerant species are thought to use AFPs as cryoprotectants to prevent the damage of freezing, but not freezing altogether. The exact mechanism is still unknown. However, it is thought AFPs may inhibit recrystallization and stabilize cell membranes to prevent damage by ice. They may work in conjunction with ice nucleating proteins (INPs) to control

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1188-472: The AFPs and antifreezes arose after the lineages that gave rise to these various insects diverged. The similarities they do share are the result of convergent evolution. Many microorganisms living in sea ice possess AFPs that belong to a single family. The diatoms Fragilariopsis cylindrus and F. curta play a key role in polar sea ice communities, dominating the assemblages of both platelet layer and within pack ice. AFPs are widespread in these species, and

1242-577: The bones, resulting in a body density approaching neutral, to fill a variety of niches. The spleen may be used to remove ice crystals from circulating blood. As the chilly Antarctic and sub-Antarctic waters of the Southern Ocean average −1 to 4 °C (30–39 °F), most species of these regions produce antifreeze glycoproteins to prevent the formation of ice crystals in blood and other body fluids. The concentration of antifreeze glycoproteins can vary with differing environmental conditions, such as colder environments caused by location. Larger amounts of

1296-514: The book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,

1350-847: The chemical and physical properties of antifreeze proteins. In 1992, Griffith et al. documented their discovery of AFP in winter rye leaves. Around the same time, Urrutia, Duman and Knight (1992) documented thermal hysteresis protein in angiosperms. The next year, Duman and Olsen noted AFPs had also been discovered in over 23 species of angiosperms , including ones eaten by humans. They reported their presence in fungi and bacteria as well. Recent attempts have been made to relabel antifreeze proteins as ice structuring proteins to more accurately represent their function and to dispose of any assumed negative relation between AFPs and automotive antifreeze, ethylene glycol . These two things are completely separate entities, and show loose similarity only in their function. Numerous fields would be able to benefit from

1404-438: The closely related Tenebrio and Dendroides beetles are homologous and each 12–13 amino-acid repeat is stabilized by an internal disulfide bond. Isoforms have between 6 and 10 of these repeats that form a coil, or beta-solenoid. One side of the solenoid has a flat ice-binding surface that consists of a double row of threonine residues. Other beetles (genus Rhagium ) have longer repeats without internal disulfide bonds that form

1458-470: The cold, nutrient-rich waters of the Southern Ocean. The Nototheniidae family includes some of the most ecologically and evolutionarily important fish in the Antarctic ecosystem, making them a crucial subject for scientific study. Nototheniidae is a family of perciform fish that are primarily found in the Southern Ocean surrounding Antarctica, with some species also occurring in the sub-Antarctic regions of

1512-508: The development of the Antarctic Circumpolar Current was formed over 30 million years ago. The cooling of Antarctic imposed from this current caused a mass extinction of teleost species that were unable to withstand freezing temperatures. Notothenioids species with the antifreeze gylcoprotein were able to survive the glaciation event and diversify into new niches. This independent development of similar adaptations

1566-506: The family Nototheniidae: These subfamilies are not recognised in the 5th Edition of Fishes of the World . Nototheniidae fishes have fusiform or elongate and oblong bodies. They typically have two dorsal fins , the first having 3 to 11 spines and the second having 25–42 segmented fin rays. The anal fin is similar to the second dorsal fin and has 22 to 40 segmented rays. All but the last dorsal and anal fin rays are branched. The caudal fin

1620-540: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and

1674-447: The formation of ice. Efc IBP produces also thermal hysteresis gap, but this ability is not as efficient as the ice-recrystallization inhibition ability. Efc IBP helps to protect both purified proteins and whole bacterial cells in freezing temperatures. Green fluorescent protein is functional after several cycles of freezing and melting when incubated with Efc IBP. Escherichia coli survives longer periods in 0 °C temperature when

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1728-625: The freezing point of organism's proteins. Bayer-Giraldi et al. 2010 found 30 species from distinct taxa with homologues of ice antifreeze proteins. The diversity is consistent with previous research that has observed the presence of these genes in crustaceans, insects, bacteria, and fungi. Horizontal gene transfer is responsible for the presence of ice antifreeze proteins in two sea diatom species, F. cylindrus and F. curta. AFPs are thought to inhibit ice growth by an adsorption –inhibition mechanism. They adsorb to non basal planes of ice, inhibiting thermodynamically-favored ice growth. The presence of

1782-413: The growth of ice pyramidal planes so as to depress the freeze point. The above mechanism can be used to elucidate the structure-function relationship of other antifreeze proteins with the following two common features: In the 1950s, Norwegian scientist Scholander set out to explain how Arctic fish can survive in water colder than the freezing point of their blood. His experiments led him to believe there

1836-481: The internal disulfide bonds. The AFP from midges is structurally similar to those from Tenebrio and Dendroides , but the disulfide-braced beta-solenoid is formed from shorter 10 amino-acids repeats, and instead of threonine, the ice-binding surface consists of a single row of tyrosine residues. Springtails (Collembola) are not insects, but like insects, they are arthropods with six legs. A species found in Canada, which

1890-496: The introduction of AFPs into ice cream and yogurt products. This ingredient, labelled ice-structuring protein, has been approved by the Food and Drug Administration . The proteins are isolated from fish and replicated, on a larger scale, in genetically modified yeast. There is concern from organizations opposed to genetically modified organisms (GMOs) who believe that antifreeze proteins may cause inflammation. Intake of AFPs in diet

1944-470: The lab with a nanolitre osmometer . Organisms differ in their values of thermal hysteresis. The maximum level of thermal hysteresis shown by fish AFP is approximately −3.5 °C (Sheikh Mahatabuddin et al., SciRep)(29.3 °F). In contrast, aquatic organisms are exposed only to −1 to −2 °C below freezing. During the extreme winter months, the spruce budworm resists freezing at temperatures approaching −30 °C. The rate of cooling can influence

1998-598: The major fish resource in the Southern Ocean, many notothens are under increasing pressure from commercial fishing , particularly the Patagonian toothfish and the Antarctic toothfish . Family (biology) Family ( Latin : familia , pl. : familiae ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between

2052-432: The other AFPs in the following aspects: There are a number of AFPs found in insects, including those from Dendroides , Tenebrio and Rhagium beetles, spruce budworm and pale beauty moths, and midges (same order as flies). Insect AFPs share certain similarities, with most having higher activity (i.e. greater thermal hysteresis value, termed hyperactive) and a repetitive structure with a flat ice-binding surface. Those from

2106-662: The presence of AFP genes as a multigene family indicates the importance of this group for the genus Fragilariopsis . AFPs identified in F. cylindrus belong to an AFP family which is represented in different taxa and can be found in other organisms related to sea ice ( Colwellia spp., Navicula glaciei , Chaetoceros neogracile and Stephos longipes and Leucosporidium antarcticum ) and Antarctic inland ice bacteria ( Flavobacteriaceae ), as well as in cold-tolerant fungi ( Typhula ishikariensis , Lentinula edodes and Flammulina populicola ). Several structures for sea ice AFPs have been solved. This family of proteins fold into

2160-485: The product; it merely makes production more efficient and prevents the death of fish that would otherwise be killed to extract the protein. Currently, Unilever incorporates AFPs into some of its American products, including some Popsicle ice pops and a new line of Breyers Light Double Churned ice cream bars. In ice cream, AFPs allow the production of very creamy, dense, reduced fat ice cream with fewer additives. They control ice crystal growth brought on by thawing on

2214-484: The protection of tissue damage by freezing. Businesses are currently investigating the use of these proteins in: Unilever has obtained UK, US, EU, Mexico, China, Philippines, Australia and New Zealand approval to use a genetically modified yeast to produce antifreeze proteins from fish for use in ice cream production. They are labeled "ISP" or ice structuring protein on the label, instead of AFP or antifreeze protein. One recent, successful business endeavor has been

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2268-457: The protein thought to facilitate this hydrogen bonding were mutated, the hypothesized decrease in antifreeze activity was not observed. Recent data suggest hydrophobic interactions could be the main contributor. It is difficult to discern the exact mechanism of binding because of the complex water-ice interface. Currently, attempts to uncover the precise mechanism are being made through use of molecular modelling programs ( molecular dynamics or

2322-516: The proteins have been found in species with habitats in higher latitudes, due to the higher expression of the protein and longer degradation time compared to relatives in more temperate regions, portraying flexible temperature regulation. Some species exhibit polymorphism , for example, the circum-Antarctic Trematomus newnesi exists as two morphs in the Ross Sea , the typical morph and a large-mouthed/broad-headed morph. Nototheniidae species are

2376-491: The ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae , but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging

2430-525: The rate of ice propagation following freezing. There are many known nonhomologous types of AFPs. Antifreeze glycoproteins or AFGPs are found in Antarctic notothenioids and northern cod . They are 2.6-3.3 kD. AFGPs evolved separately in notothenioids and northern cod. In notothenioids, the AFGP gene arose from an ancestral trypsinogen-like serine protease gene. The classification of AFPs became more complicated when antifreeze proteins from plants were discovered. Plant AFPs are rather different from

2484-566: The same function despite their diversity: Antifreeze glycoprotein activity has been observed across several ray-finned species including eelpouts, sculpins, and cod species. Fish species that possess the antifreeze glycoprotein express different levels of protein activity. Polar cod ( Boreogadus saida) exhibit similar protein activity and properties to the Antarctic species, T. borchgrevinki . Both species have higher protein activity than saffron cod ( Eleginus gracilis ). Ice antifreeze proteins have been reported in diatom species to help decrease

2538-480: The seafloor, while others are pelagic and swim in the water column. Some species migrate seasonally to different habitats for feeding or spawning purposes. Due to their abundance in the Southern Ocean, Nototheniidae is an important part of the food chain for many marine predators, including seals, whales, and birds. Nototheniidae species have no swim bladder , however, they have other depth-related adaptations, such as increased fatty tissues and reduced mineralization of

2592-449: The southern hemisphere. They are known for their unique adaptations to the cold, such as the ability to produce antifreeze proteins to prevent their bodily fluids from freezing. The family includes over 100 species, making it the most diverse group of fish in the Southern Ocean. Nototheniidae inhabits a variety of habitats, from shallow coastal waters to deep ocean trenches. Many species are bottom-dwellers and can be found in rocky areas or on

2646-543: The species Notothenia coriiceps which Richardson had also described in 1844 subsequently being designated as the type in 1862 by Theodore Nicholas Gill . The name Notothenia means "coming from the south", a reference to the Antarctic distribution of the genus. They are traditionally placed in the order Perciformes together with their relatives, Actual phylogenetic relationships among species of suborder Notothenioidei have not yet been determined with certainty. The following subfamilies and genera are classified within

2700-427: The thermal hysteresis value of AFPs. Rapid cooling can substantially decrease the nonequilibrium freezing point, and hence the thermal hysteresis value. Consequently, organisms cannot necessarily adapt to their subzero environment if the temperature drops abruptly. Species containing AFPs may be classified as Freeze avoidant : These species are able to prevent their body fluids from freezing altogether. Generally,

2754-519: The two fish orders have similar antifreeze proteins, cod species contain arginine in AFG, while Antarctic notothenioid do not. The role of arginine as an enhancer has been investigated in Dendroides canadensis antifreeze protein (DAFP-1) by observing the effect of a chemical modification using 1-2 cyclohexanedione. Previous research has found various enhancers of this bettles' antifreeze protein including

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2808-488: Was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted the use of this term solely within

2862-403: Was reported. Among the five solutes, citrate was shown to have the greatest enhancing effect. This is an example of a proto-ORF model, a rare occurrence where new genes pre exist as a formed open reading frame before the existence of the regulatory element needed to activate them. In fishes, horizontal gene transfer is responsible for the presence of Type II AFP proteins in some groups without

2916-438: Was “antifreeze” in the blood of Arctic fish. Then in the late 1960s, animal biologist Arthur DeVries was able to isolate the antifreeze protein through his investigation of Antarctic fish. These proteins were later called antifreeze glycoproteins (AFGPs) or antifreeze glycopeptides to distinguish them from newly discovered nonglycoprotein biological antifreeze agents (AFPs). DeVries worked with Robert Feeney (1970) to characterize

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