Hemolin is an

immunoglobulin An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...

-like protein exclusively found in

Lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

(moths and butterflies). It was first discovered in immune-challenged pupae of ''

Hyalophora cecropia ''Hyalophora cecropia'', the cecropia moth, is North America's largest native moth. It is a member of the family Saturniidae, or giant silk moths. Females have been documented with a wingspan of five to seven inches (160 mm) or more. These m ...

'' and ''

Manduca sexta ''Manduca sexta'' is a moth of the family Sphingidae present through much of the Americas. The species was Species description, first described by Carl Linnaeus in his 1763 ''Centuria Insectorum''. Commonly known as the Carolina sphinx moth and ...

''. Hemolin has a horseshoe crystal structure with four domains and resembles the developmental protein neuroglian. Hemolin and neuroglian 3D

Hemolin increases 18-fold up to 7 mg/ml following injection of bacteria in ''H. cecropia''. Induction of Hemolin in moths after bacterial injection have been shown in several species including ''

Antheraea pernyi ''Antheraea pernyi'', the Chinese (oak) tussar moth, Chinese tasar moth or temperate tussar moth, is a large moth in the family Saturniidae. The species was first described by Félix Édouard Guérin-Méneville in 1855. '' Antheraea roylei'' is a ...

'', ''

Bombyx mori The domestic silk moth (''Bombyx mori''), is an insect from the moth family Bombycidae. It is the closest relative of ''Bombyx mandarina'', the wild silk moth. The silkworm is the larva or caterpillar of a silk moth. It is an economically imp ...

'', ''

Helicoverpa zea ''Helicoverpa zea, ''commonly known as the corn earworm, is a species (formerly in the genus ''Heliothis'') in the family Noctuidae. The larva of the moth ''Helicoverpa zea'' is a major agricultural pest. Since it is polyphagous (feeds on many ...

'', ''

Heliothis virescens ''Chloridea virescens'', commonly known as the tobacco budworm, is a moth of the family Noctuidae found throughout the eastern and southwestern United States along with parts of Central America and South America. It is a major pest of field cro ...

'', ''

Hyphantria cunea The fall webworm (''Hyphantria cunea'') is a moth in the family Erebidae known principally for its larval stage, which creates the characteristic webbed nests on the tree limbs of a wide variety of hardwoods in the late summer and fall. It is con ...

'', and ''

Samia cynthia ''Samia cynthia'', the ailanthus silkmoth, is a saturniid moth, used to produce silk fabric but not as domesticated as the silkworm, ''Bombyx mori''. The moth has very large wings of , with a quarter-moon shaped spot on both the upper and lower ...

''. Hemolin has also been suggested to participate in the immune response to virus infection and shown to bind to virus particles. It is expressed in response to

dsRNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...

in a dose-dependent manner. '' Galleria melonella'' responds to

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...

intake by increased Hemolin protein expression. Hemolin is thought to be a gene duplication of the developmental protein neuroglian, but has lost two of the protein domains that neuroglian contains. In the potential function as a developmental protein, Hemolin has been shown to increase close to

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

tion in ''

'', and is induced during diapause and by

20-Hydroxyecdysone 20-Hydroxyecdysone (ecdysterone or 20E) is a naturally occurring ecdysteroid hormone which controls the ecdysis (moulting) and metamorphosis of arthropods. It is therefore one of the most common moulting hormones in insects, crabs, etc. It is als ...

in ''

Lymantria dispar ''Lymantria dispar'', also known as the gypsy moth or the spongy moth, is a species of moth in the family Erebidae. ''Lymantria dispar'' is subdivided into several subspecies, with subspecies such as ''L. d. dispar'' and ''L. d. japonica'' bei ...

''.

RNAi RNA interference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expression by double-stranded RNA, through translational or transcriptional repression. Historically, RNAi was known by o ...

of Hemolin causes malformation in ''H. cecropia''.{{cite journal, last=Bettencourt, first=R., author2=Terenius, O. , author3=Faye, I. , title=Hemolin gene silencing by ds-RNA injected into Cecropia pupae is lethal to next generation embryos, journal=Insect Molecular Biology, date=June 2002, volume=11, issue=3, pages=267–271, doi=10.1046/j.1365-2583.2002.00334.x, pmid=12000646, doi-access=free

References

Immunology Insect immunity

See also

References