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87-678: Aphaniptera Flea , the common name for the order Siphonaptera , includes 2,500 species of small flightless insects that live as external parasites of mammals and birds . Fleas live by ingesting the blood of their hosts. Adult fleas grow to about 3 millimetres ( 1 ⁄ 8 inch) long, are usually brown, and have bodies that are "flattened" sideways or narrow, enabling them to move through their hosts' fur or feathers. They lack wings; their hind legs are extremely well adapted for jumping. Their claws keep them from being dislodged, and their mouthparts are adapted for piercing skin and sucking blood . Some species can leap 50 times their body length,

174-615: A "professor" accompanied their performance with a rapid circus patter. Oriental rat fleas , Xenopsylla cheopis , can carry the coccobacillus Yersinia pestis . The infected fleas feed on rodent vectors of this bacterium, such as the black rat , Rattus rattus , and then infect human populations with the plague , as has happened repeatedly from ancient times, as in the Plague of Justinian in 541–542. Outbreaks killed up to 200 million people across Europe between 1346 and 1671. The Black Death pandemic between 1346 and 1353 likely killed over

261-403: A 1.8 m (6 ft) adult human jumping 110 m (361 ft) vertically and 200 m (656 ft) horizontally. Rarely do fleas jump from dog to dog. Most flea infestations come from newly developed fleas from the pet's environment. The flea jump is so rapid and forceful that it exceeds the capabilities of muscle, and instead of relying on direct muscle power, fleas store muscle energy in

348-432: A feat second only to jumps made by another group of insects, the superfamily of froghoppers . Flea larvae are worm-like, with no limbs; they have chewing mouthparts and feed on organic debris left on their hosts' skin. Genetic evidence indicates that fleas are a specialised lineage of parasitic scorpionflies (Mecoptera) sensu lato , most closely related to the family Nannochoristidae . The earliest known fleas lived in

435-485: A female's lifetime (fecundity) varies from around one hundred to several thousand. In some species, the flea lives in the host's nest or burrow and the eggs are deposited on the substrate, but in others, the eggs are laid on the host itself and can easily fall off onto the ground. Because of this, areas where the host rests and sleeps become one of the primary habitats of eggs and developing larvae. The eggs take around two days to two weeks to hatch. Flea larvae emerge from

522-456: A flea under the microscope in his pioneering book Micrographia published in 1665, poems by Donne and Jonathan Swift , works of music by Giorgio Federico Ghedini and Modest Mussorgsky , a play by Georges Feydeau , a film by Charlie Chaplin , and paintings by artists such as Giuseppe Crespi , Giovanni Battista Piazzetta , and Georges de La Tour . John Donne's erotic metaphysical poem " The Flea ", published in 1633 after his death, uses

609-612: A large collection of fleas now in the Rothschild Collection at the Natural History Museum, London . He discovered and named the plague vector flea, Xenopsylla cheopis , also known as the oriental rat flea, in 1903. Using what was probably the world's most complete collection of fleas of about 260,000 specimens (representing some 73% of the 2,587 species and subspecies so far described), he described around 500 species and subspecies of Siphonaptera. He

696-402: A pad of the elastic protein named resilin before releasing it rapidly (like a human using a bow and arrow). Immediately before the jump, muscles contract and deform the resilin pad, slowly storing energy which can then be released extremely rapidly to power leg extension for propulsion. To prevent premature release of energy or motions of the leg, the flea employs a "catch mechanism". Early in

783-440: A part of the fly gene in the bacterium Escherichia coli . Active studies are investigating potential application of recombinant resilins in biomedical engineering and medicine. After its discovery in elastic tendons in dragon flies and wing hinges in locusts , resilin has been found in many structures and organs in arthropods . Resilin is often found as a composite with chitin in insect cuticle , where chitin serves as

870-510: A polymeric scaffold to mimic the extracellular matrix in order to generate a cell and tissue responses. Though this field of research is still ongoing, it has generated a wide amount of interest in the scientific community and is currently being investigated for a variety of biomedical applications in areas of tissue regeneration and repair. One unique property of rec1-Resilin is its ability to be identified due to autofluorescence. Fluorescence for resilin stems primarily from dityrosine, which are

957-401: A range of hosts, only parasitise species with low immune responses. In general, host specificity decreases as the size of the host species decreases. Another factor is the opportunities available to the flea to change host species; this is smaller in colonially nesting birds, where the flea may never encounter another species, than it is in solitary nesting birds. A large, long-lived host provides

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1044-446: A result of frequent scratching and biting by the animal. They can also cause anemia in extreme cases. Fleas are vectors for viral , bacterial and rickettsial diseases of humans and other animals, as well as of protozoan and helminth parasites. Bacterial diseases carried by fleas include murine or endemic typhus and bubonic plague . Fleas can transmit Rickettsia typhi , Rickettsia felis , Bartonella henselae , and

1131-558: A rubber, the dehydrated resilin has the properties of a glassy polymer. However, dehydrated resilin is able to return to its rubbery state if water is available. Water serves as a plasticizer in resilin network by increasing the amount of hydrogen bonds. The high concentration of proline and glycine, polyproline helices, and hydrophilic portions all serves to increase water content in resilin protein network. The increase in hydrogen bonds lead to an increase in chain mobility, thus decreases glass transition temperature . The more water content

1218-552: A similar sperm pump organisation. Relationships of Siphonaptera per Tihelka et al. 2020. Diptera (true flies) [REDACTED] Boreidae (snow scorpionflies, 30 spp.) [REDACTED] Nannochoristidae (southern scorpionflies, 8 spp.) Siphonaptera (fleas, 2500 spp.) [REDACTED] Pistillifera (scorpionflies, hangingflies, 400 spp .) [REDACTED] Fleas likely descended from scorpionflies , insects that are predators or scavengers. Fossils of large, wingless stem-group fleas with siphonate (sucking) mouthparts from

1305-612: A single host group; these include the Malacopsyllidae ( armadillos ), Ischnopsyllidae ( bats ) and Chimaeropsyllidae ( elephant shrews ). Many of the known species are little studied. Some 600 species (a quarter of the total) are known from single records. Over 94% of species are associated with mammalian hosts, and only about 3% of species can be considered to be specific parasites of birds . The fleas on birds are thought to have originated from mammalian fleas; at least sixteen separate groups of fleas switched to avian hosts during

1392-408: A sizeable fraction of the world's people. Fleas appear in human culture in such diverse forms as flea circuses ; poems, such as John Donne 's erotic " The Flea "; works of music, such as those by Modest Mussorgsky ; and a film by Charlie Chaplin . Fleas are wingless insects, 1.5 to 3.3 millimetres ( 1 ⁄ 16 to 1 ⁄ 8 inch) long, that are agile, usually dark colored (for example,

1479-531: A source of annoyance, however. Flea bites cause a slightly raised, swollen, irritating nodule to form on the epidermis at the site of each bite, with a single puncture point at the centre, like a mosquito bite. This can lead to an eczematous itchy skin disease called flea allergy dermatitis , which is common in many host species, including dogs and cats. The bites often appear in clusters or lines of two bites, and can remain itchy and inflamed for up to several weeks afterwards. Fleas can lead to secondary hair loss as

1566-511: A stable environment that favours host-specific parasites. Although there are species named dog fleas ( Ctenocephalides canis Curtis, 1826) and cat fleas ( Ctenocephalides felis ), fleas are not always strictly species-specific. A study in Virginia examined 244 fleas from 29 dogs: all were cat fleas. Dog fleas had not been found in Virginia in more than 70 years, and may not even occur in

1653-487: A sufficient amount of energy input can be stored in the material, and released afterwards. An example of energy input is to stretch the material. Natural resilin (hydrated) has a resilience of 92%, which means it can store 92% of the energy input for release during unloading, indicating a very efficient energy transfer. In order for a better understanding the stiffness and strain of resilin, Hooke's Law should be taken into consideration. For linear springs, Hooke's Law states that

1740-427: A taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follow consistent naming schemes . Orders of plants , fungi , and algae use the suffix -ales (e.g. Dictyotales ). Orders of birds and fishes use

1827-567: A third of the population of Europe. Because fleas carry plague, they have seen service as a biological weapon . During World War II , the Japanese army dropped fleas infested with Y. pestis in China. The bubonic and septicaemic plagues are the most probable form of the plague that would spread as a result of a bioterrorism attack that used fleas as a vector. The banker Charles Rothschild devoted much of his time to entomology , creating

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1914-460: A wide variety of warm-blooded vertebrates including dogs, cats, rabbits, squirrels, ferrets, rats, mice, birds, and sometimes humans. Fleas normally specialise in one host species or group of species, but can often feed but not reproduce on other species. Ceratophyllus gallinae affects poultry as well as wild birds. As well as the degree of relatedness of a potential host to the flea's original host, it has been shown that avian fleas that exploit

2001-433: A year and a half. Completely developed adult fleas can live for several months without eating, so long as they do not emerge from their puparia . Optimum temperatures for the flea's life cycle are 21 to 30 °C (70 to 86 °F) and optimum humidity is 70%. Adult female rabbit fleas, Spilopsyllus cuniculi , can detect the changing levels of cortisol and corticosterone hormones in the rabbit's blood that indicate it

2088-472: Is a relatively small order of insects: members of the order undergo complete metamorphosis and are secondarily wingless (their ancestors had wings which modern forms have lost). In 2005, Medvedev listed 2005 species in 242 genera, and despite subsequent descriptions of new species, bringing the total up to around 2500 species, this is the most complete database available. The order is divided into four infraorders and eighteen families. Some families are exclusive to

2175-466: Is believed to contribute in the self-assembling process and the elasticity of the protein. The elastic mechanism of resilin is proposed to be entropy related. Under relaxed state, the peptide is folded, and possesses a large entropy, but once it is stretched out, the entropy decreases as the peptide unfold. The coexistence of PPII and beta-turn play an important role of increasing entropy as resilin returns to its disordered form. The other function of PPII

2262-399: Is getting close to giving birth. This triggers sexual maturity in the fleas and they start producing eggs. As soon as the baby rabbits are born, the fleas make their way down to them and once on board they start feeding, mating, and laying eggs. After 12 days, the adult fleas make their way back to the mother. They complete this mini-migration every time she gives birth. Between 1735 and 1758,

2349-416: Is in resilin network, the less stiff and more resilient the material is. Dehydrated resilin behaves as a glass polymer with low stiffness, strain, and resilience, but a relatively high compressible modulus and glass transition temperature. Rubber like proteins, such as resilin and elastin, are characterized based on their high resilience , low stiffness , and large strain . A high resilience indicate that

2436-430: Is mainly hydrophilic, and is more extended when immersed in water. In contrast, exon 3 encoded peptide contains both hydrophobic and hydrophilic blocks, suggesting the formation of micelles, where the hydrophobic block will cluster on the inside with the hydrophilic portion surrounding it. Thus, a single complete resilin protein, when immersed in water, takes on the structure in which exon 1 encoded segment extends out from

2523-409: Is not able to fit in the alpha-helices. However, the segments of resilin are able to take on secondary structure forms at different conditions. Like other biomaterials, resilin is a hydrogel , meaning it is swollen with water. The water content of resilin at neutral pH is 50-60%, and the absence of this water will make a big difference on the material's property: while the hydrated resilin behaves like

2610-420: Is to facilitate self-assembling process: it is found that the quasi-extended PPII is able to interact through an intermolecular reaction, and initiate the formation of fibrillar supramolecular structure. While the secondary structures are determined by energy state and hydrogen bonds formed between amino acids, hierarchical structures are determined by the hydrophobicity of the peptide. Exon 1 encoded peptide

2697-659: The Prodromus Systematis Naturalis Regni Vegetabilis of Augustin Pyramus de Candolle and the Genera Plantarum of Bentham & Hooker, it indicated taxa that are now given the rank of family (see ordo naturalis , ' natural order '). In French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille (plural: familles )

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2784-592: The Boreidae (snow scorpionflies) is not supported. A 2020 genetic study recovered Siphonaptera within Mecoptera, with strong support, as the sister group to Nannochoristidae , a small, relictual group of mecopterans native to the Southern Hemisphere. Fleas and nannochoristids share several similarities with each other that are not shared with other mecopterans, including similar mouthparts as well as

2871-640: The Ischnopsyllidae only on bats , and the Chimaeropsyllidae only on elephant shrews . The oriental rat flea, Xenopsylla cheopis , is a vector of Yersinia pestis , the bacterium that causes bubonic plague . The disease was spread to humans by rodents, such as the black rat , which were bitten by infected fleas. Major outbreaks included the Plague of Justinian , about 540, and the Black Death , about 1350, each of which killed

2958-486: The cat flea , vector of bubonic plague ) [REDACTED] Ceratophyllomorpha (inc. the Ceratophyllidae , such as the widespread moorhen flea ) [REDACTED] As of 2023, there are 21 recognized families within the order Siphonaptera, 3 of which are extinct. In addition, some researchers have suggested that the subfamily Stenoponiinae should be elevated to its own family ( Stenoponiidae ). Fleas feed on

3045-899: The conceit of a flea, which has sucked blood from the male speaker and his female lover, as an extended metaphor for their sexual relationship. The speaker tries to convince a lady to sleep with him, arguing that if the mingling of their blood in the flea is innocent, then sex would be also. The comic poem Siphonaptera was written in 1915 by the mathematician Augustus De Morgan , It describes an infinite chain of parasitism made of ever larger and ever smaller fleas. Flea circuses provided entertainment to nineteenth century audiences. These circuses, extremely popular in Europe from 1830 onwards, featured fleas dressed as humans or towing miniature carts, chariots , rollers or cannon . These devices were originally made by watchmakers or jewellers to show off their skill at miniaturization. A ringmaster called

3132-466: The myxomatosis virus. They can carry Hymenolepiasis tapeworms and Trypanosome protozoans. The chigoe flea or jigger ( Tunga penetrans ) causes the disease tungiasis , a major public health problem around the world. Fleas that specialize as parasites on specific mammals may use other mammals as hosts; thus, humans may be bitten by cat and dog fleas. Fleas have appeared in poetry, literature, music and art; these include Robert Hooke 's drawing of

3219-696: The Latin suffix -iformes meaning 'having the form of' (e.g. Passeriformes ), but orders of mammals and invertebrates are not so consistent (e.g. Artiodactyla , Actiniaria , Primates ). For some clades covered by the International Code of Zoological Nomenclature , several additional classifications are sometimes used, although not all of these are officially recognized. In their 1997 classification of mammals , McKenna and Bell used two extra levels between superorder and order: grandorder and mirorder . Michael Novacek (1986) inserted them at

3306-774: The Middle Jurassic to Early Cretaceous have been found in northeastern China and Russia, belonging to the families Saurophthiridae and Pseudopulicidae , as well as Tarwinia from the Early Cretaceous of Australia. Most flea families formed after the end of the Cretaceous (in the Paleogene and onwards). Modern fleas probably arose in the southern continental area of Gondwana , and migrated rapidly northwards from there. They most likely evolved with mammal hosts, only later moving to birds . Siphonaptera

3393-479: The Middle Jurassic ; modern-looking forms appeared in the Cenozoic . Fleas probably originated on mammals first and expanded their reach to birds. Each species of flea specializes, more or less, on one species of host: many species of flea never breed on any other host; some are less selective. Some families of fleas are exclusive to a single host group; for example, the Malacopsyllidae are found only on armadillos ,

3480-499: The N-terminal, segment encoded by exon 1 contains 18 copies of a 15-residue repeating sequence (GGRPSDSYGAPGGGN); segment corresponding to exon 2 contains 62 amino acids of the chitin-binding Rebers-Riddiford (R-R) consensus sequence ( Pfam PF00379 ); exon 3 encoded peptide is dominated by 11 copies of a 13-residual repeating sequence (GYSGGRPGGQDLG). While enriched glycine and proline in exon 1 and 3 introduce cyclic structures into

3567-645: The Swedish naturalist Carl Linnaeus first classified insects, doing so on the basis of their wing structure. One of the seven orders into which he divided them was "Aptera", meaning wingless, a group in which as well as fleas, he included spiders , woodlice and myriapods . It wasn't until 1810 that the French zoologist Pierre André Latreille reclassified the insects on the basis of their mouthparts as well as their wings, splitting Aptera into Thysanura (silverfish), Anoplura (sucking lice) and Siphonaptera (fleas), at

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3654-469: The US, so a flea found on a dog is likely a cat flea ( Ctenocephalides felis ). One theory of human hairlessness is that the loss of hair helped humans to reduce their burden of fleas and other ectoparasites. In many species, fleas are principally a nuisance to their hosts, causing an itching sensation which in turn causes the host to try to remove the pest by biting, pecking or scratching. Fleas are not simply

3741-506: The adult form. This can take just four days, but may take much longer under adverse conditions, and there follows a variable-length stage during which the pre-emergent adult awaits a suitable opportunity to emerge. Trigger factors for emergence include vibrations (including sound), heat (in warm-blooded hosts), and increased levels of carbon dioxide , all of which may indicate the presence of a suitable host. Large numbers of pre-emergent fleas may be present in otherwise flea-free environments, and

3828-558: The basic structure shown in the cladogram. The Hectopsyllidae , including the harmful chigoe flea or jigger , is sister to the rest of the Siphonaptera. Hectopsyllidae (inc. jigger ) [REDACTED] Pygiopsyllomorpha Macropsyllidae , Coptopsyllidae Neotyphloceratini , Ctenophthalmini , Doratopsyllinae Stephanocircidae [REDACTED] clade inc. Rhopalopsyllidae , Ctenophthalmidae , Hystrichopsyllidae [REDACTED] Chimaeropsyllidae Pulicidae (inc.

3915-432: The chemical cross-links , in which R groups of Tyrosine and Dityrosine add to the backbone of the growing peptide chain. Andersen came to this conclusion based on a study involving these two compounds in which he was able to rule out other forms of cross linking such as disulfide bridges, ester groups, and amide bonds. Though the mechanism of cross-linking of Tyrosine is understood that occurs through radical initiation,

4002-408: The composition of resilin contributes greatly to the elasticity of resilin. Resilin, however, has an absence of an alpha-helix leading to a randomly coiled structure and a disordered structure. This is primarily due to the significantly high proline content in resilin. Proline is a bulky amino acid that has the ability to cause a kink the peptide chain and due to the sterically hindered side chains, it

4089-467: The cross linking of resilin still remains a mystery. Cross linking of resilin occurs very quickly and this is possibly a result of temperature. At increasing temperature, the rate of cross linking of the residues increases and leads to a highly cross-linked resilin network. The amino acid composition of resilin indicates that proline and glycine has a relatively high presence in the amino acid composition of resilin. The presence of glycine and proline in

4176-418: The diet included nonviable eggs. They are blind and avoid sunlight, keeping to dark, humid places such as sand or soil, cracks and crevices, under carpets and in bedding. The entire larval stage lasts between four and 18 days. Given an adequate supply of food, larvae pupate and weave silken cocoons after three larval stages. Within the cocoon, the larva molts for a final time and undergoes metamorphosis into

4263-464: The dissolution of the testicular plug in males, and copulation soon follows. Some species breed all year round while others synchronise their activities with their hosts' life cycles or with local environmental factors and climatic conditions. Flea populations consist of roughly 50% eggs, 35% larvae, 10% pupae, and 5% adults. The number of eggs laid depends on species, with batch sizes ranging from two to several dozen. The total number of eggs produced in

4350-415: The eggs to feed on any available organic material such as dead insects, faeces, conspecific eggs, and vegetable matter. In laboratory studies, some dietary diversity seems necessary for proper larval development. Blood-only diets allow only 12% of larvae to mature, whereas blood and yeast or dog chow diets allow almost all larvae to mature. Another study also showed that 90% of larvae matured into adults when

4437-472: The ending -anae that was initiated by Armen Takhtajan 's publications from 1966 onwards. The order as a distinct rank of biological classification having its own distinctive name (and not just called a higher genus ( genus summum )) was first introduced by the German botanist Augustus Quirinus Rivinus in his classification of plants that appeared in a series of treatises in the 1690s. Carl Linnaeus

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4524-411: The evolutionary history of the Siphonaptera. Occurrences of fleas on reptiles is accidental, and fleas have been known to feed on the hemolymph (bloodlike body fluid) of ticks . Flea phylogeny was long neglected, the discovery of homologies with the parts of other insects being made difficult by their extreme specialization. Whiting and colleagues prepared a detailed molecular phylogeny in 2008, with

4611-536: The fatigue lifetime of resilin, we can think about this intuitively. If we consider the case of honey bees, where they live for around 8 weeks during which they fly 8 hours a day, flapping wings at 720,000 cycles/h, they are likely to flap their wings more than 300 million times [9]. Since resilin functions over the entire lifetime of insects, its fatigue lifetime should be considerably large. However, in live insects, resilin molecular can be produced and replaced constantly, which introduces an error in our conclusion. Due to

4698-473: The feces of mature fleas, which contain dried blood. Adults feed only on fresh blood. Their legs are long, the hind pair well adapted for jumping; a flea can jump vertically up to 18 centimetres (7 inches) and horizontally up to 33 cm (13 in), making the flea one of the best jumpers of all known animals (relative to body size), second only to the froghopper . A flea can jump 60 times its length in height and 110 times its length in distance, equivalent to

4785-910: The field of zoology , the Linnaean orders were used more consistently. That is, the orders in the zoology part of the Systema Naturae refer to natural groups. Some of his ordinal names are still in use, e.g. Lepidoptera (moths and butterflies) and Diptera (flies, mosquitoes, midges, and gnats). In virology , the International Committee on Taxonomy of Viruses 's virus classification includes fifteen taxomomic ranks to be applied for viruses , viroids and satellite nucleic acids : realm , subrealm , kingdom , subkingdom, phylum , subphylum , class, subclass, order, suborder, family, subfamily , genus, subgenus , and species. There are currently fourteen viral orders, each ending in

4872-458: The fields of biomedical engineering and medicine. In particular, hydrogels composed of recombinant resilins have been utilized as tissue engineering scaffolds for mechanically-active tissues including cardiovascular, cartilage and vocal cord tissues. Early work has focused on optimizing the mechanical properties, chemistry and cytocompability of these materials, but some in vivo testing of resilin hydrogels has also been performed. Researchers at

4959-450: The force required to deform the spring is directly proportional to the amount of deformation by a constant which is the characteristic of the spring. A material is viewed as elastic when it can be deformed to a large extend with a limited amount of force. Hydrated resilin has a tensile modulus of 640-2000 kPa, an unconfined compressive modulus of 600-700 kPa, and a strain to break of 300%. Although there has been no actual data acquired for

5046-469: The gene product. The Drosophila melanogaster gene is composed of 4 exons , which encode for 4 functional segments in CG15920: signal peptide and 3 peptide encoded by exon 1, 2, and 3. The signal peptide guides pro-resilin into extracellular space, where resilin proteins aggregate and cross link to form a network, and then is cut off from the peptides, so that nascent resilin becomes mature resilin. From

5133-566: The hairs or feathers on the host's body. The flea body is covered with hard plates called sclerites. These sclerites are covered with many hairs and short spines directed backward, which also assist its movements on the host. The tough body is able to withstand great pressure, likely an adaptation to survive attempts to eliminate them by scratching. Fleas lay tiny, white, oval eggs. The larvae are small and pale, have bristles covering their worm-like bodies, lack eyes, and have mouth parts adapted to chewing. The larvae feed on organic matter, especially

5220-497: The introduction of a suitable host may trigger a mass emergence. Once the flea reaches adulthood, its primary goal is to find blood and then to reproduce. Female fleas can lay 5000 or more eggs over their life, permitting rapid increase in numbers. Generally speaking, an adult flea only lives for 2 or 3 months. Without a host to provide a blood meal, a flea's life can be as short as a few days. Under ideal conditions of temperature, food supply, and humidity, adult fleas can live for up to

5307-439: The jump, the tendon of the primary jumping muscle passes slightly behind the coxa-trochanter joint, generating a torque which holds the joint closed with the leg close to the body. To trigger jumping, another muscle pulls the tendon forward until it passes the joint axis, generating the opposite torque to extend the leg and power the jump by release of stored energy. The actual take off has been shown by high-speed video to be from

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5394-415: The lifetime of adult insects and must therefore operate for hundreds of millions of extensions and contractions ; its elastic efficiency ensures performance during the insect's lifetime. Resilin exhibits unusual elastomeric behavior only when swollen in polar solvents such as water. In 2005, a recombinant form of the resilin protein of the fly Drosophila melanogaster was synthesized by expressing

5481-579: The low stiffness and high resilience. Cross linked peptides encoded by exon 1 have a resilience greater than 93%, while that encoded by exon 3 has a resilience of 86%. In addition, natural resilin has a resilience of 92%, similar to that of exon 1, suggesting again that exon 1 may play a more important role in the elastic property of resilin. Andersen, in 1996, discovered that the tyrosine residues are involved in chemically covalent cross-links in many forms such as dityrosine , trityrosine, and tetratyrosine. Primarily, in resilin, tyrosine and dityrosine served as

5568-407: The micelle exon 3 encoded peptide forms. Once resilin is transferred to the outside of the cell, their exon 2 encoded peptides, the chitin binding segments, bind to chitin. Meanwhile, di- or tri-tyrosine crosslinking is formed by oxidative coupling , mediated by peroxidase , between tyrosine residuals. Like other elastomeric proteins, the degree of cross linking in resilin is low, which ensures

5655-543: The most important aspects of successful rec1-Resilin synthesis is that its mechanical properties match that of the original resilin (native resilin). In the study indicated above, Scanning Probe Microscopy (SPM) and Atomic Force Microscopy (AFM) were used to investigate the mechanical properties of rec1-Resilin and native resilin. The results of these tests revealed that the resilience of both recombinant and native resilin were relatively similar but can differ in its applications. In this study, rec1-Resilin could be placed into

5742-402: The moth family Pyralidae , where both high elasticity and high resilience of resilin play important roles due to the rapid stress-release cycles of sound-producing tymbals . Besides these structures, resilin exists most widely in the locomotion systems of arthropods. It was discovered in wing hinges to enable recovery from deformation of wing elements, and to dampen the aerodynamic forces felt by

5829-563: The population. Recombinant resilin was first studied in 2005 when it was expressed in Escherichia coli from the first exon of the Drosophila Melanogaster 's CG15920 gene. During its study, pure resilin was synthesized into 20% protein-mass hydrogel and was cross-linked with ruthenium-catalyzed tyrosine in the presence of ultraviolet light. This reaction yielded the product, recombinant resilin (rec1-Resilin). One of

5916-594: The properties of rec1-Resilin can be applied to other clinical applications within the field of Materials Engineering and Medicine. This study on recombinant resilin has led to several years of research on the use of resilin like proteins for several biomedical applications that retains the mechanical properties of resilin. The ongoing results of the studies involving recombinant resilin may lead to further research in which other unexplored mechanical properties and chemical structure of resilin may be investigated. Recombinant resilins have been studied for potential application in

6003-445: The protein, tyrosine residuals are able to form di- and tri- tyrosine cross-links between proteins. Resilin is a disordered protein; however its segments may take on secondary structures under different conditions. It is discovered that peptide sequence encoded by exon 1 exhibit an unstructured form and cannot be crystallized, which allows the peptide sequence segment to be very soft and highly flexible. Exon 3 encoded peptide takes on

6090-464: The reddish-brown of the cat flea ), with a proboscis , or stylet, adapted to feeding by piercing the skin and sucking their host's blood through their epipharynx. Flea legs end in strong claws that are adapted to grasp a host. Unlike other insects, fleas do not possess compound eyes but instead only have simple eyespots with a single biconvex lens; some species lack eyes altogether. Their bodies are laterally compressed, permitting easy movement through

6177-512: The remarkable rubber elasticity of resilin, scientists began exploring recombinant versions for a variety of material and medical applications. With the rise in DNA technologies, this field of research has seen a rapid increase in the synthesis of biosynthetic protein polymers that can be tuned to having certain mechanical properties. Thus, this field of research is rather promising and can provide new methods for treating diseases and disorders that affect

6264-449: The resilience of rec1-Resilin to other rubbers, a scanning probe microscope of used. This study compared the resilience of rec1-Resilin to two different types of rubber: chlorobutyl rubber and polybutadiene rubber, both rubbers with high resilience properties. This study concluded that rec1-Resilin was 92% resilient compared to chlorobutyl rubber at 56% and polybutadiene rubber at 80%, respectively. With such high mechanical resilience ,

6351-401: The resilin isolated from locust tendon has been reported to be 97% (only 3% of stored energy is lost as heat). It does not have any regular structure but its randomly coiled chains are crosslinked by di- and tri- tyrosine links at the right spacing to confer the elasticity needed to propel some jumping insects distances up to 38 times their length (as found in fleas). Resilin must last for

6438-511: The result of crosslinks of tyrosine residues. When ultraviolet light irradiates a sample of rec1-Resilin at 315 nm to 409 nm emissions, the rec1-Resilin begins to show blue fluorescence. An example of the blue fluorescence exhibited by the dityrosine residues in resilin is shown in the figure below of a flea. Another unique property of resilin is its high resilience. Recombinant resilin demonstrated excellent mechanical properties similar to that of pure resilin. Elvin et al. aimed to compare

6525-420: The same position. Michael Benton (2005) inserted them between superorder and magnorder instead. This position was adopted by Systema Naturae 2000 and others. In botany , the ranks of subclass and suborder are secondary ranks pre-defined as respectively above and below the rank of order. Any number of further ranks can be used as long as they are clearly defined. The superorder rank is commonly used, with

6612-534: The same time separating off the arachnids and crustaceans into their own subphyla. The group's name, Siphonaptera, is zoological Latin from the Greek siphon (a tube) and aptera (wingless). It was historically unclear whether the Siphonaptera are sister to the Mecoptera (scorpionflies and allies), or are inside that clade, making "Mecoptera" paraphyletic. The earlier suggestion that the Siphonaptera are sister to

6699-399: The structural component. Resilin provides elasticity and possibly other properties. It has been discovered in the salivary pump of assassin bugs ( Rhodnius prolixus ), tsetse flies , and honey bees , and in the resistance providing mechanism for the venom-dispensing pump of honey bee stingers . Resilin has also been found in the sound production organs of arthropods, such as cicadas and

6786-538: The suffix -virales . Resilin Resilin is an elastomeric protein found in many insects and other arthropods. It provides soft rubber-elasticity to mechanically active organs and tissue; for example, it enables insects of many species to jump or pivot their wings efficiently. Resilin was first discovered by Torkel Weis-Fogh in locust wing-hinges. Resilin is currently the most efficient elastic protein known (Elvin et al., 2005). The elastic efficiency of

6873-421: The tibiae and tarsi rather than from the trochantera (knees). Fleas are holometabolous insects, going through the four lifecycle stages of egg , larva , pupa , and imago (adult). In most species, neither female nor male fleas are fully mature when they first emerge but must feed on blood before they become capable of reproduction. The first blood meal triggers the maturation of the ovaries in females and

6960-416: The unstructured form before loading, but transforms to an ordered beta-turn structure once stress is applied. Meanwhile, segment encoded by exon 2 serves as a chitin binding domain. It is proposed that as stress is applied, or there is energy input, exon 1 encoded peptide responds immediately due to its high flexibility. Once this occurs, the energy is passed onto exon 3 encoded peptide, which transforms from

7047-517: The unstructured form to beta-turn structure to store energy. Once the stress or energy is removed, exon 3 encoded segment reverses the structural transformation and outputs the energy to exon 1 encoded segment. Another secondary structure exon 1 and exon 3 corresponding peptides may take on is the polyproline helix (PPII), indicated by the high occurrence of proline and glycine in these 2 segments. The PPII structure widely exists in elastomeric proteins, such as abductin , elastin , and titin . It

7134-416: The wing; in ambulatory systems of cockroaches and flies to facilitate rapid joint deformation; in jumping mechanisms, resilin stores kinetic energy with great efficiency and releases it upon unloading. It is also abundant in the cuticle surrounding the abdomens of termites, ants, and bees, which expand and swell to a great extent during feeding and reproduction process. Amino acid composition in resilin

7221-525: The word family ( familia ) was assigned to the rank indicated by the French famille , while order ( ordo ) was reserved for a higher rank, for what in the 19th century had often been named a cohors (plural cohortes ). Some of the plant families still retain the names of Linnaean "natural orders" or even the names of pre-Linnaean natural groups recognized by Linnaeus as orders in his natural classification (e.g. Palmae or Labiatae ). Such names are known as descriptive family names. In

7308-483: Was analyzed in 1961 by Bailey and Torkel Weis-Fogh when they observed samples of prealar arm and wing hinge ligaments of locusts. The result indicates that resilin lacks methionine , hydroxyproline , and cysteine constituents in its amino acid composition. Resilin was identified to be a product of the Drosophila melanogaster gene CG15920 due to the similarities between amino acid compositions of resilin and

7395-439: Was followed in this interest by his daughter Miriam Rothschild , who helped to catalogue his enormous collection of the insects in seven volumes. Order (biology) What does and does not belong to each order is determined by a taxonomist , as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that

7482-551: Was the first to apply it consistently to the division of all three kingdoms of nature (then minerals , plants , and animals ) in his Systema Naturae (1735, 1st. Ed.). For plants, Linnaeus' orders in the Systema Naturae and the Species Plantarum were strictly artificial, introduced to subdivide the artificial classes into more comprehensible smaller groups. When the word ordo was first consistently used for natural units of plants, in 19th-century works such as

7569-561: Was used as a French equivalent for this Latin ordo . This equivalence was explicitly stated in the Alphonse Pyramus de Candolle 's Lois de la nomenclature botanique (1868), the precursor of the currently used International Code of Nomenclature for algae, fungi, and plants . In the first international Rules of botanical nomenclature from the International Botanical Congress of 1905,

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