Prothorax Ocelli Proto cerebrum Deuterocerebrum Antenna Trito cerebrum C Cardiaca C Allata (Ě------Esophagus Mouth Pro thoracic gland Thoracic ganglia Ventral nerve chain Ventral glands FIGURE 11-19 Generalized central nervous system and endocrine systems of an insect. The nervous system contains three major groups of neurosecretory cells: the median (mnc), lateral (lnc), and subesophageal (snc), which are connected with the corpora cardiaca via NCCI and NCCII nerves; phasmid insects have additional neurosecretory cells in the tritocerebrum (tnc) connected to the corpora cardiaca via NCCIII nerves. The corpora cardiaca are a neurohemal organ for the release of neurosecretions; they'arise from stomodeal ectoderm (shown by black arrows). The corpora allata are classical endocrine glands that arise from ectodermal invaginations near the maxillae (black arrows). The pro thoracic gland is another important classical endocrine gland; it arises (black arrow) from ventral glands (which are present in primitive insects). (Modified from Jenkin 1962; after Knowles 1963.) > Neurosekretorické buňky mozku Corpus cardiacum (CC) Corpus allatum (CA) vysoká koncentrace JH*larva l Ekdyson (ec) y^ Larva ^\ f Vajíčka ) Dospělec ^V)VeMLU\ HSgHôKJ Obr. 14.5. Hormonálni řizeni svlékání hmyzu. _Produkce ekdysonu z prothorakálních žláz je stimulována protoracikotropním hormonem (PTTH) -syntetizovaného v mozku a vylévaného z kar-diálnich tělísek (CC) . Ekdyson iniciuje svlé-kací děje. Zda se vytvoří kutikula kuklová nebo opět larvální, rozhodne koncentrace ju-venilního hormonu (JH). Ten je produkován v tělískách přilehlých (CA). PTTH neurosecretory cells have cell bodies in the brain... Brain ,,.ancf axon terminals in the corpora allata. The corpora a I lata aiso contain nonneurai endocrine cells that secrete JH. Juvenile hormone The prothoracic gland secretes ecdysone. The tracheae are branched tubes that extend from openings called spiracles in the body wall. Inka cell Spiracle Inka cells, located on the tracheae, secrete PETH and ETR TABLE 14.6 Major hormones and neurohormones that control insect metamorphosis Hormone Type of molecule Type of signal Site of secretion Major target tissue Action Prothoracicotropic hormone (PTTH) Ecdysone (molting hormone) Juvenile hormone (JH) Eclosion hormone (EH) Protein (~5000 molecular weight) Steroid Neuroendocrine Endocrine Terpene (fatty-acid derivative) Peptide Pre-ecdysis triggering Peptide hormone (PETH) Ecdysis triggering hormone (ETH) Bursicon Peptide Large protein (-35,000 molecular weight) Endocrine Neuroendocrine Endocrine Endocrine Neuroendocrine ßrain,with axon terminals extending to corpora allata Prothoracic glands in larva/nymph; ovary in adult Corpora allata Brain Inka ceils of tracheae Inka cells of tracheae Brain and nerve cord Prothoracic glands Epidermis in larva/nymph; fat body in adult Epidermis in larva/ nymph; ovary in adult Inka cells, possibly others Neuronal circuits in brain Neuronal circuits in brain Cuticle and epidermis Initiates molting (ecdysis) by stimulating release of ecdysone from prothoracic glands When activated to 20-hydroxyec-dysone, promotes cellular mechanisms to digest old cuticle and synthesize new one; stimulates production of yolk proteins in adult Opposes formation of adult structures and promotes formation of larval/nymphal structures; functions as a gonadotropin in the adult Promotes PETH and ETH secretion from Inka cells Coordinates motor programs to prepare for shedding the cuticle Coordinates final motor programs for escaping from old cuticle Tans and hardens new cuticle Sources:After Randall,Burggren, and French 2002;and Žitňan ec al.2003. Přehled hmyzích hormonů L Ekdysteroidy - ekdyson, 20-hydroxyekdyson (20-E), makisteron A (=24-metyl-20E), 2-deoxyekdyson, 26-hydroxyekdyson a další 2, Juvenilní hormony JH-I, JH~n, JH-III, JH-0, 4-metyl-JH-I, kyselina juvenilního hormonu 3. Peptidické neu roh o r m ony L Hormony řídící metabolismus a homeostázu 1, Adipokinetické hormony (AKH) a hypertrehalosemické hormony 2« Diuretické hormony 3, Antidíuretické hormony 4. Chloride transport stimulating hormone a ion transport peptide II. Hormony řídící metamorfózur vývoj a růst 1, Prothoracikoíropní hormon (PTTH) a bombyxin 2, prothoracikostatický hormon (PTSH) 3, Allatostatiny a allatotropin 4, P BAN I? II, III (pheromone biosynthesis activating neuropeptide) 5, Eklozní hormon a ccdysh triggering hormone (ETH) 6, Burzikon 7, Faktory regulující puparizací much S, Diapauzni hormon III. Hormony řídící pohlavní funkce 1. stimulační gonádotropní neurohormony (gonadotropiny): - ovary maturing par sin (OMP) - egg development neurohormone (EDNH) (=o var i an ecdysteroidogenic factor) 2. inhibiční neurohormony (antigonadotropiny, folikulostatiny): - neuroparsin - oostatícké hormony a TMOF (tryps in-modulating oostatic factor) VL Hormony modifikující svalovou kontrakci (myotropní peptidy) 1, Proctolin 1. Kardiosti mutační hormony - crustacean cardioactive peptide (CC A P) 3. Skupiny myotropní ch neurohonnonü - myokininy, sulfakininy, pyrokiny-ny, tachykininy, myoinhibiční peptídy, periviscerokininy, FMRF-amíd V. Hormony řídící barvoměnu (chromatotropiny) 1. PDF - pigment dispersing factor 2. MRCH - melanization and reddish coloratig hormone (identický s PBAN) 4 S e 7 8 9 10 t time in each stage (days} 18 19 1 Fig, 15 JO. Changes in hormon« titers regulating molting and metamorphosis in a holometaboJous insect. At the molt from larva to larva, juvenile hormone is present du ring the critical period;« the molt from larva to pupa, no juvenile hormone is present at the first critical period. The second critical period of sensitivity to iuvenile hormone in the fifth stage larva regulates development of the imiginal discs. Edoston hormone and bursicon are produced for a brief period btfure and after each ecdysis (based on data for Manducn, Lepidoptera),