Endokrinní disrupce II - bezobratlí J. Vondráček Hormonální regulace u bezobratlých: oblast intenzivního výzkumu - praktické aspekty ochrany zemědělských plodin; endokrinní disrupce jako faktor ovlivňující stabilitu ekosystémů; I přehledné publikace jsou poměrně zastaralé - především primární zdroje; otázka definice - endokrinní orgány (Mollusca) vs. endokrinní buňky (Annelida) Hormonální regulace u bezobratlých: COLOR CHANGES REPRODUCTION Á -* SEX DFľERKCN ATTON -> GONADAL ACTIVITY HORMONES GROWTH CONTINUOUS ■*■ DISCONTINUOUS ■HOMOSTASY * METABOLISM + GLYCAEMIA + OSMGLARIľY. neuropeptidy vs. klasické hormony LoFont, Ecotoxicology 9: 41-57, 2000 Hormonální regulace u bezobratlých: TABLE I Examples of Reported Hormones in Different Invertebrate Taxaa Taxon Reported hormones (example, com roiled process) Coelenterata Ne ma tod a Mollusea Annelida Neuropeptides |(glyeine-leueine tryptophan amides = GL Warn ides, metamorphosis): thyroids (thyroxine, strobilation); retinoids (9-eis-retinoie aeid, strobilation) Eedy steroids \reported but functional role questionably terpenoids (juvenile hormone (JII) like hormones, growth); neuropeptides (F M RF am id e. ft in ction unkno wn) Eedy steroids (reported but functional role questionable): steroids (1713-estradioL testosterone, progesterone, sexual differentiation, reproduction in prosobranchs); terpenoids (JII reported but functional role questionable); neuropeptides (APGWamide. dorsal body hormone (DBII), sexual differentiation, gonad maturation, spawning: egg-laying hormone (ELII), spawning; FMRFamide, neuromodulation: mollusean insulin-like peptides (MIPs), growth, development, energy metabolism) Eedy steroids (eedysone, functional role unknown); neuropeptides (F M RF am id e, n euro modulation) Hormony u členovců Eedy steroids (eedysone. molting, vitellogenesis); steroids (17B-estradiol, testosterone, progesterone, functional role under debate); terpenoids (methyl famesoate (MF). metamorphosis, reproduction): neuropeptides (androgenie hormone, sexual differentiation, vitellogenesis inhibition: erustaeean hyperglyeemie hormone family (CI II I), energy metabolism: molt-inhibiting hormone (Mill). ecdysteroid production: vitellogenesis-inhibiting hormone (VIII). vitellogenesis) Eedysteroids (eedysone, molting, egg maturation): terpenoids (JII, metamorphosis, reproduction); neuropeptides (adipokinetie hormone (AKII), energy metabolism; allatostatin and allatotropin, JH production; bombyxin, ecdysteroid production, energy metabolism; bursieon, cuticle tanning; diapause hormone, embryonic diapause; diuretie hormone (DII), water homeostasis; eedysis-triggering hormone (ETII) and eelosion hormone (EII). ecdy sis behavior; FMRFamides. neuromodulation; prothoraeiotrophie hormone (PTTII), ecdysteroid production) Hormony u ostnokozcu a plastencu: Echinodermata | Steroids |progesterone, testosterone. 17B-estradiol. estrone. vitellogenesis, oogenesis, spermatogenesis, spawning); neuropeptides (gonad-stimulating substanee = GSS. spawning; maturation-promoting factor = MPFfertilisation) Tunieata Steroids (testosterone, 17B-estradiol, oogenesis, spermatogenesis, spawning): neuropeptides (gonadotropin releasing hormone analogue, gonad development): | thyroids^thyroxine, probably tanning process during tunic formation) Metamorfóza hmyzu: (A) AMETAHOIjOUíí (B) HEMIMETABOiOĽS DEVELOPMENT DEVELOPMENT Fronymph Adult Nymph ÍO MOLOMETABOLOUS DEVELOPMENT Larva f instil r 1) Larva (instar 2) Pupa Adult Modes of insect development. Molts are represented as arrows. (A) Ametabolous (direct) development in a silverfish. After a brief pronymph stage, the insect looks like a small adult. (B) Hemimetabolous (gradual) metamorphosis in a cockroach. After a very brief pronymph phase, the insect becomes a nymph. After each molt, the next nymphal instar looks more like an adult, gradually growing wings and genital organs. (C) Holometabolous (complete) metamorphosis in a moth. After hatching as a larva, the insect undergoes successive larval molts until a metamorphic molt causes it to enter the pupal stage. Then an imaginal molt turns it into an adult. (A) (B) Brain - Neurosecretory tdJs Juvenile hormone OH Regulation OCH. Juvenile hanbbflt(fH) a I latum cardiacum Prothor&cicotropic hormone (PTTH) jh-jijrp 2(J - Hydroxyecdysunc 4:l>rorr]osyme^ ENA ^' S1" DimQrization {weak: DNA binding induced) AF-2 {Ligand dependent, cell and promoter specific) TRi ncocraaaxiy S Metabolism Fig. 1. (a) Schematic of the ■structural and function.'! I uKinni/fitMiul NNs. I In.1 i.wlutioiKii y o vixl regions C (DBD) and E (LBD) are indicated as boxes and a black line represents the divergent regions A/B. D and F Two transcription AFs have been described in several NRs, a const itutively active [if taken □ utof the context of the receptor) AF-1 in region A.'B and a ligand-inducible AF-2 in region E. Within these AFs- ads have been defined, (b) Estrogen receptor DBD complex on a cognate DNA response element, (c) Agonist-induced changes of the LED., allowing binding of coacti valors (the bound coactivator-binding peptide is shown). Figures 1 b.c are three-dimensional views derived from the corresponding crystal structures. Abbreviations: See Glossary Another candidate for the JH receptor role is the Methoprene-tolerant (Met) Per-Arnt-Sim (PAS) domain protein, whose loss confers tolerance to JH and its mimic methoprene in the fruit fly Drosophila melanogaster. (Konopova et al., 2007. C! Progesterone 1"" Z1 ■liydrmtylasc |17^-QH Dehydrogenase] i>::ihEH fc-o j t: _ t3 OH In iron-Eh on break in DBD (a-d*) a Ý P-box G(n)7tEG£KGFFKR a* 2B- :-:f LI FRR P boa P -box ^ IF FRR EGCKG P-bOK T EGCKAFFKRtnVG EACKA GSCKV 3A 3B 3PH VERTEBRATES ARTHROPODS 4»i C. etegans and Jellyfish RXRs-------U53>-----dellyfisri RXR TUK--- COUP-TFs9 LX Rs FXR--- VDR PXR/OfJR CAR5 NQFU -NURR1 ERs CR AF PR MR ni - 5VP- EcR e utínat) □hr3s b - CeNHR-67 - CeUNC-55 ---CěNHR-ZS CeSEX-1 CCNR14) - - - CeNHR-S (CNR*) fi Vertebrates Arthropods Jellyfish (TripedaJia EcR receptory: r AI A2 A3 3 4 5 ó £cJ?mKNA DNA-binding site T Bcdysonc-bindiiig site EcR-A protoin Alternative spi icjng -1- Rl B2 3 4 5 6 USD r EcR-Rl protein B2 3 4 5 í fccR -B2 protein Formation of the ecdysone receptors. Alternative mRNA splicing of the ecdysone receptor (EcH) transcript creates three types of EcR mRNAs. These generate proteins having the same DNA-binding site (blue) and hydroxyecdysone-binding site (red), but with very different amino termini. EcR receptory hree isoforms of EcR have been identified in insects, each with a different, stage-specific role in regulation of molting and development. This allows for one steroid hormone to induce a variety of different tissue responses. In general, EcR A is predominant when cells are undergoing a maturation response (from juvenile to adult) and is predominant in imaginal discs, whereas EcR B1 predominates in juvenile cells during proliferation or regression. Little is known about the function of the EcR B2 isoform. DNAand hormone binding are similar in the three isoforms of EcR. However, the EcR that has been cloned from the crab, Uca pugilator (U31817', GenBank), shares 85-87% homology with that of Drosophila (M74078, GenBank). The differences are primarily in the region of the molecule involved with dimerization. Similar sequence similarities are found between the heterodimeric partner, USP. There are several ecdysteroids which bind EcR, including 20-hydroxyecdysone, turkesterone, makisterone A, ponasterone A, and muristerone A. Some arthropods may use specific ecdysteroids as their principal molting hormone, but often several ecdysteroids are found within one group. The primary molting hormone for a range of organisms, including some insects and Crustacea, is 20-OH ecdysone (20 HE). Among other examples, makisterone A is an important hormone for some Crustacea and hemipteran insects. Struktury ecdysteroidu: 20-OH Ecdysonc (20 HE) Muri stero ne A (MurA) OH H,CH0 Synthesis of molting hormones <0 I Cholesterol (from diet- a vitamin for insects) Prothoracic gland mono-oxygenase (fat body, epidermis) Metabolites (excretion) Conjugates (storage) Ecdysone 20- Hydroxy ecdysone Prothoracicotropic hormone (PTTH) o Protein of 30-kDa active as a homodimer linked by a disulfide bond o Produced by two pairs of lateral neurosecretory cells c> Released from corpora allata (moths) or corpora cardiaca (most insects) LNSC III ( NCC 1*11 cc ca 7 r PTTH cells of Manduca visualized with anti-PTTH antibody The role of PTTH Ecdysone synthesis and secretion are initiated by prothoracicotropic hormone (PTTH), a hormone produced by two pairs of neurosecretory cells in the brain. PTTH was first isolated and characterized from the silkmoth Bombyx mori. PTTH has conserved seven cysteine residues, several hydrophobic regions and an A/-glycosylation site. Only the homodimeric form of Bombyx PTTH is biologically active. Bombyx PTTH is thought to be a member of the transforming growth factor-p (TGF-p) family. ■ Initiates every molt - stimulates prothoracic glands to synthesize and release ecdysone - serves as "mission control" allowing molt if the conditions are right • factors affecting decision to molt are species-specific - stretch of the abdomen by a blood meal in Rhodnius - completion of the cocoon in some moths - escape from wet diet in flies Fytoekdosteroidy • Phytoecdysteroids (PEs) are a family of about 200 plant steroids related in structure to the invertebrate steroid hormone 20-hydroxyecdysone. • PEs are attracting renewed attention because of their specific effects on invertebrate development (potential in invertebrate pest control) and their varied benign pharmacological actions on mammals (biomedical applications and gene switches). In the past three decades, several thousand species of plants have been surveyed for the presence of PEs and the structures of over 200 PEs have been deduced. The most frequently encountered PE is 20E, the principal physiological inducer of moulting and metamorphosis in arthropods. Syntéza ekdysteroidů a úloha cytochromů P450 Syntéza ekdysteroidů a úloha cytochromů P450 Fig. 5. (Parts 1 and 2). The biosynthesis of 20-hydroxyecdysone from plant sterols. Question marks denote possible involvement of P450 enzymes. Note specifically where the Halloween gene products act (red). 3-Dehydroecdysone is synthesized in the prothoracic glands of many insects (e.g. Manduca sexto.) and converted to ecdysone in the hemolymph (left column of part 2). For Drosophila, ecdysone is synthesized in the prothoracic gland cells of the ring gland (right column of part 2). Juvenilní hormon a jeho analogy: OCH; Jíl III Pyriproxyfen Fig. 1. Chemical structures of J H 111 and J H As. Metamorfóza hmyzu: (A) AMETAHOIjOUíí (B) HEMIMETABOiOĽS DEVELOPMENT DEVELOPMENT Fronymph Adult Nymph ÍO MOLOMETABOLOUS DEVELOPMENT Larva f instil r 1) Larva (instar 2) Pupa Adult Modes of insect development. Molts are represented as arrows. (A) Ametabolous (direct) development in a silverfish. After a brief pronymph stage, the insect looks like a small adult. (B) Hemimetabolous (gradual) metamorphosis in a cockroach. After a very brief pronymph phase, the insect becomes a nymph. After each molt, the next nymphal instar looks more like an adult, gradually growing wings and genital organs. (C) Holometabolous (complete) metamorphosis in a moth. After hatching as a larva, the insect undergoes successive larval molts until a metamorphic molt causes it to enter the pupal stage. Then an imaginal molt turns it into an adult. Juvenilní hormon a jeho analogy: Insect juvenile hormones are critical developmental hormones that have direct effects on both larval development and adult reproductive competence. Most insect orders appear to synthesize a single JH homolog, methyl (2E,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate (JH III) but Lepidoptera and at least some Diptera synthesize additional homologs. Although not well documented, regulation of JH production is complicated and involves endogenous neural, neuroendocrine signals and, in some cases, male produced exogenous regulators transferred to the female during mating Among virgin females, JH is required for vitellogenesis and, thus, females do not become reproductively competent until JH production is stimulated. To date, only two neuropeptides that regulate JH biosynthesis in adult Lepidoptera have been identified. These were identified e.g. from the tobacco hornworm moth (Manduca sexta): allatotropin (Gly-Phe-Lys-Asn-Val-Glu-Met-Met-Thr-Ala-Arg-Gly-Phe-NH2) allatostatin (pGlu-Val-Arg-Phe-Arg-Gln-Cys-Tyr-Phe-Asn-Pro-lle-Ser-Cys-Phe-COOH). c 1 W) o « o Si -52 ™ U U O) Oí o -= c/> — O ■E 03 2 Insect Pheromone B lochem i and Molecular Biology Ts = ď o *s SI O) "O "13! « je qj c = tn £ i ■s So « J2 o £ j§ 0) 3 Feromony jsou strukturně vysoce odlišné látky Syntéza feromonu muže být přímo regulována hormony PROPIONATE VAL1NE ISOLEUCľNE METHIONINE ACETYL-OjA 00l O Propkjnyl-CuA ^Y^SCoA \ASCoA Carboxylase^ CH} METHYLMALONYL-CoA SCoA PROP]ONYL-Ci)A Methylmalonyl-CfiA Míjlase Vitamin O SUCCINYL-CoA Methylmalonyl-CoA Decarboxylase FATTY ACID SYNTHESIS ELONGATION o n-_1,ll-D[METHYLTR]ACONTANOYL-G)A 1- co2 Cytochrome P-450 HYDROCARBON nadpH.Oj FORMATION 3,11-D1METHYLNONACOSANE JH Induced Step * CH3 3.11 -DIMETHYLNONACOSAN-2-OL Í, 11 -DIMETHYLNONACOSAN-7-ONF. Fig. 2. Blattodean pheromone biosynthetic pathways utilize fatty acid biosynthesis from malonyl-CoA and methylmalonyl^CoA substrates followed by cytochrome P-450-mediated decarboxylation, hydroxylation, and oxidation. The hydroxylation step is regulated by JH III (adapted from Chase et al, 1992 for Blattella germanica sex pheromone components). Coleopteran pheromone biosynthetic pathways as exemplified for Ips spp. [e.g. Ips pini (Say)] and acyclic monoterpenoid (ipsdienol) pheromone biosynthesis. The classical mevalonate-based isoprenoid pathway is regulated by juvenile hormone III (JH III) at enzymatically catalyzed steps prior to mevalonate. Feeding on host Pinusspp. phloem induces synthesis of JH III by the corpora allata. ACETYL-CoA ■ Fatty Acid Synthase -» Malanyl-CoA NADPH 18:0:CoA- r 23:l:Hy - HYDROCARBON FORMATION _A_ co2 . 24:1:AI 1/1-9-1 KK'OSENE \ Cytochrome P450 NADPH, 02 (Z)-9,10-EPOXYTRICOSANE (Z)-14-TRICOSEN-10-ONE 27:1:%- co2 Microsomal Desaturase NADPH O, -A9-18:l:CoA 20:l:CoA Reductase 22:l:CoA 24:l:CoA 28:1:A1 Cytochrome P450 NADPH, 02 Vitellogenic i females 1 Males + 20-E T Males + ovaries 26:1 :CoA 28:1 :CoA Males Non-vitellogenic females Ovariectomized females Microsomal > Acyl-CoA Elongase ( Malonyl-CoA^ V NADPH / _ Proposed separate elongase system 77 Y" 20-HYDROXY-ECDYSONE Fig. 4. Dipteran pheromone biosynthetic pathways utilize fatty acid synthesis, desaturation, elongation, and reductive decarboxylation. The proposed regulatory steps for 20-hydroxyecdysone are the secondary elongation system. Unsaturated hydrocarbons can be further modified to the epoxides (adapted from Blomquist et al., 1987a for the common house fly, Musca domestica L. sex pheromone components). Endokrinní disrupce u bezobratlých The issue of endocrine disruption (ED) in invertebrates has generated remarkably little interest in the past compared to research with aquatic vertebrates in this area. However, with more than 95% of all known species in the animal kingdom, invertebrates constitute a very important part of the global biodiversity with key species for the structure and function of aquatic and terrestrial ecosystems. Despite the fact that ED in invertebrates has been investigated on a smaller scale than in vertebrates, invertebrates provide some of the best documented examples for deleterious effects in wildlife populations following an exposure to endocrine-active substances. The principal susceptibility of invertebrates to endocrine-active compounds is demonstrated with the case studies of tributyltin effects in mollusks and of insect growth regulators, the latter as purposely synthesized endocrine disrupters. Imposex The first adverse effects of TBT on mollusks were observed in Crassostrea gigas at the Bay of Arcachon, one of the centers of oyster aquaculture in Europe with ball-shaped shell deformations in adults, and a dramatically decline of annual spatfall. These effects led to a break-down of local oyster production in the bay with marked economic consequences. Laboratory and field analyses revealed that TBT from antifouling paints was the causative agent with trace concentrations as low as 10 to 20 ng TBT/L in ambient water being already effective. Another TBT effect in molluskswas initially described in a number of regions worldwide in the early 1970s without identifying the organotin compound as the causative agent at that time: A virilization of female prosobranchs, which has been termed as imposex. Imposex is characterized by the formation of a penis and/or vas deferens on females of gonochoristic prosobranch species and is induced at lower concentrations than all other described TBT effects. Furthermore, it is a specific response of organotin compounds under field conditions. Today, imposex is known to occur in more than 150 prosobranch species. Imposex: zc. llydrabia idvac. r.r.il?Lltclj-_ ir.icm-iraphs of lernales lheir mantle cavity opened. Lei I: normal female without impose\: right: sterilized female in the final stage oTimposev with blocked oviduct. Abbreviations: K.d. capsule gland: OvU Ooparous opening ofoviduct [open lell: blocked right): PP. Penis: T. tentacle: Vd. vas deferens. The periwinkle Littorina littorea develops a closely related virilization phenomenon as a response to TBT exposure, termed as intersex. Intersex females are either characterized by male features on female pallial organs, specifically by an inhibition of the ontogenetic closure of the pallial oviduct or female sex organs are supplanted by the corresponding male formations particularly by a prostate gland. Comparably to imposex, the intersex response is a gradual transformation of the female pallial tract, which can be described by an evolutive scheme with four stages. Intersex development causes restrictions of the reproductive capability of females. In stage 1, a loss of sperm during copulation is possible and consequently the reproductive success is reduced. Females in stages 2-4 are definitively sterile because the capsular material is spilled into the mantle cavity (stage 2) or the glands responsible for the formation of egg capsules are missing (stages 3 and 4). Due to female sterility, periwinkle populations can be in decline but are not likely to become extinct because of the planktonic veliger larvae produced by the species, as long as aqueous TBT levels are not beyond mortality threshold concentrations for the larvae (Matthiessen et al. 1995). Imposex 0 1 I 1 1 1 1 I 1 5 10 i 1 1 1 1 i 1 ■ 15 20 i 1 1 1 1 i 1 25 30 ng TBT-Sn/L in ambient water Fig, 2 Nucella lapillus. Relationship between aqueous TBT concent rations and imposex intensities; y = (5.54 x) / (1.12 4 x); n = 151 population samples from 81 stations; r = 0.688; />< 0.0005. One of the most important lessons to be learned from the "TBT story" and its effects in mollusks is that EDCs may impact different levels of biological integrations from molecules to communities affecting also the survival of populations in the field. Furthermore, the case history of TBT provides evidence for vertebrate-type steroids playing an important functional role in a number of invertebrate groups, including prosobranchs. : . I . ■ ... ' I 1 i. :•-.■_* " r. * "l mí. Alternative Insecticides: Insect Growth Regulators * "Nature and the pesticide industry apparently have decided that the best way to poison an animal is through its nervous system" ♦ most insecticides are nerve poisons, so mammalian selectivity must arise from differences in pharmacokinetics or metabolism * a better wav to go: find chemicals that attack biological processes unique to insects = biorational design • insects must shed their skin periodically to grow = molting • insects undergo metamorphosis between life stages • both processes are under strict endocrine control • 1. juvenile hormone (JH) titer in blood determines the next step in development; 2. Ecdysone (molting hormone) stimulates the molting process • insecticides have been developed that mimic JH and ecdysone ♦ practical problem: agent must be present at the critical period to influence development (narrow window of susceptibility) * Met ho pie ne (Precor, Altosid) - first commercial JH mimic (Zoecon, 1978). LD50 = 34,600, MSR = 1.7 x 106 • used as a mosquito larvicide (approved by WHO in drinking water for mosquito control); feed to livestock to control tlies in manure; home control of fleas; control of stored product pests, mushroom pests. Used in Japan on silkworms to increase silk production. ♦ about 10 additional JH mimics have been commercialized • Tebufenozide (Mimic, Confirm) - first commercial ecdysone agonist (Rohm & Haas, 1991). LD50 > 5000 mg/kg • very effective against Lepidoptera and Colorado potato beetle - induces lethal premature molting • first insecticide jointly registered ^r^, by the EPA (USA) and the PMRA AA_/^c~t1"N~^H h (Canada), 1996 tcbufcnn/idc &ilfli m. ■ ■■■■ • Diilubenzuron (Dimilin) - first commercial chit in synthesis inhibitor (Phillips, 1972). LD50 = 4640 mg/kg. • prevents insects from completing a molt by interfering with the synthesis of chitin, the main constituent of the integument. Not a direct action on chitin synthetase, but prevents the final step in activation of the enzyme. Slow acting, • major uses: boll weevil on cotton, gypsy moth and other forest pests - used in Kitsilano in 197° against gypsy moth C-NH-C-NH-II I o o \ -CI diflubcnaunm lufcnurun • Lufenuron f Prouram) - developed by Novartis in 1994. Oral ICR for Ilea control in dogs and cats - prevents egg development. • LDS0 = 2000 mg/kg; pet dose - 20 mg kg Polycyklické aromatické uhlovodíky mohou aktivovat EcR: Compound ( hemical slniclurc Steroid interactions References li 20-OII lxdysone (20 HE) Muristerone A (MurA) Benzo[a]pyrene iliaPi Benzo[r|nuoranthene (BbF) Pyrene Chrysene Aroclor 1254 Ecdysone agonist Ecdysone agonist AliR agonist Anti-estrogen Anti-androgen Not estrogenic in fish AliR agonist X XX X X = HorC], 54% Cl No A Ii R ať t i vat i on AliR agonist No estrogen receptor (ER) interaction AliR agonist Thyroid hormone Not antiestrogen Estrogenic (?) in fish Cottam and Milner(1997) Yao el a I. (1993) Cottam and Milner (1QQT) Yao et al. i 1993) Hankinson (1995) Tran et al. (1996) Chang and l.iao (1987) Thomas and Smith (1993) Hankinson (1995) Poland and K n lit son (1982) Hankinson i 1995) Tran et al. (19961 llaiikiiison i l'i'öi Jacobson and Jacobson (1996) Goldey et al. (1995) Krishnan and Safe (1993) Flouriot etat. (1995) Thomas and Smith (1993) Polycyklické aromatické uhlovodíky mohou aktivovat EcR: r i Mu r A only ETOgg 1 nM (0.01 ppm) + Mur A Benza[a]pyrene Pyrene Chrysene Aroclorl254 Benzo[b]fluoranthenc (ppm) Polycyklické aromatické uhlovodíky mohou aktivovat EcR: O X í/j 'oj U 15 í 10 5 - 0 ^2£23 25 nM + Mur A ezszs 10 j.iM +■ Mur A ■■■■■^ 1 |u>t + Mur A 6 nM Mur A ontv Benzo[a]pyrene Benzo[b]fIuoranthene Pyrene Chryscme FIG. 4, Interaction of PAHs and Muristerone A in CI,8+ cells. The four PAHs each enhance the differentiation response in CI.8+ cells. This represents the average of three assays, each done in triplicate. Bars, SEM. *p < 0.05; **/;> < 0.01 different from 6 nM Muristerone A alone. TABLE V Representative Laboratory and Field Studies in Which Endocrine Disruption May Be Occurring in Insects8. Spades Co ti l ami nun l Concentration (range), effects Lab/field Reference Chironomvs ten tans (all life singes) Macro m i'a cingulaia (larvae) Chironomvs ri'parivs (larvae-adult) Chironomvs spp. 4-Xonylphenol 12.5-2 00 pg/L; Reduced Lab survival at hijzh concentrations Tannery and 5. 10. 15. 20. 20%: Shortened paper pulp mill time to llrsl molt (tannery), effluent arrested larval molting (pttper pulp) Phathalate 100. 1000. 10000 mg/kg du- es ters INi) effects on survival. development or emergence Industrial Ambient at site: I ligber level effluent of metitum deformities in containing exposed larvae in both field metals mid lab conditions Lab Lab Kabl ctaL 1997 Subraman ian and Varadaraj 1993 Brown et at. 19% Lie Id and Dicknian and Lab Rygiel 1996 Chironomvs Organic and thummi inorganic (larvae) spp. pollutants Chironomvs Possible exposure to pollutants Ambient til site: Prevalence of Lie Id m o rp h o 1 o «i c al de fo r m i t i e s related to pollutants Ambient at site: Deformed Lie Id mouth parts, heavily pigmented head capsules, unusually thick bead capsule and bodv wall De I lis I ho veil et a!. 1995 I lam i I ton and Saether 1971 "Modified from deLur et ai (1999). TABLE III Representative Laboratory Studies in Which Endocrine Disruption May Be Occurring in Mollusks Species Co mum i ňu n l Concentration í range), ] J JOLlS Lab/Held Reference Lymnaea stagnalis Mytilus edulis (adult) DDT. MCľA 50, 500 ug/L (DDT); Lab 10, LOO mg/L (MCPA): l-ecundily alterations 100 ag/L; Spawning Lab stimulation, inhibition of gonad ial develop men I "Mod i lied fi-om deľur t-f ul (1999). Wo i n and líromnark 1002 K lay lm an s cí r[ Bisphenol A 9 \ OH 2mrr FIG. 3 Marina cornuarietis. Photographs of a control female {a) and of BPA treated "superferrmlcK" (b-c) with opened man lie cavities. In (h) and (c) a rupture in the wall of the pallial oviduct occurs (arrow) with an additional protrusion of Ihe spawning mass in (c). Abbreviations: Ed, albumen gland: K. gill: Kd. capsule gland: V. vagina. * Chemical signaling systems and their basic mechanisms in the animal kingdom exhibit a considerable degree of conservatism (MeLachlan, 2001). Consequently, invertebrate endocrine function should he affected by identical or simi]ar compounds as vertebrates (deFur et aL, 1999; Pmder and Pottinger, 1999). * Highly effective EDCs have been intentionally developed for the purpose of pest control to interfere with hormonal systems of insects Such endocrine-mediating properties can be assumed as not being unique for the IGRs or this group of arthropods but rather reflect the fact that much less research has heen undertaken for other invertebrate groups than insects. * ED in invertebrates found far less attention than in vertebrates in the pasu probably heeause their hormonal systems are poorly understood favoring investigations with vertebrates and especially fish as systematic groups for ecotoxicological research and routine analyses many scientists feel familiar with. * Little work has been done on endocrine disruption in invertebrates from the field (with the exception of the investigation of ihe imposex phenomenon in marine gastropods). The overwhelming majority of laboratory-based studies (56 reports) focuses on rnollusks (17 publications), crustaceans (15 cases) and insects (12 reports), thus continuing main tendencies in the pre-1999 literature (Fig 4a, b)