Neurohormones in insect stress: A review

The neurohormones are the master regulators of all life processes in insects and they create a strategy of stress protecting events. Neurohormones are synthesized mainly in insect brain neurosecretory neurons. Various stressors of different intensity cause specific changes which influence on neurosecretory neurons activity and synthesis of neurohormones (biogene amines, ecdysiotropins, ecdysiostatins, allatoregulatory neurohormones, adipokinetic neurohormones, etc.). Biogene amines in insects may function as neurohormones controlling carbohydrate and lipid metabolism as the primary response of the insects to the effect of stressors. Intermediary metabolism in insects is mainly regulated by adipokinetic hormones which supply organism by energy especially in extreme conditions. Stress induces changes in release of ecdysioregulatory and allatoregulatory neurohormones and modificates ecdysones and juvenile hormones synthesis in prothoracic gland and corpora allata. The involvement of hormones of an ecdysteroid or JH type in response to stress creates the danger of an untimely induction of morphogenetic process in target cells. Limiting the quantity of secreted hormones and shortening the period when target cells are sensitive to morphogenetic stimuli removes this danger.Neurohormoni regulišu sve životne procese insekata i kreiraju strategiju odgovora organizma na delovanje stresora. Neurohormoni se u najvećoj meri sintetišu u neurosekretnim neuronima protocerebralnog regiona mozga insekata. Stresori različitih osobina i intenziteta specifično menjaju aktivnost neurosekretnih neurona i sintezu neurohormona (biogenih amina, egdizotropina, egdizostatina, alatoregulatornih neurohormona, adipokinetičkih neurohormona itd.). Biogeni amini imaju ulogu u kontroli metabolizma ugljenih hidrata i lipida u početnim fazama stresnog odgovora insekata. Intermedijerni metabolizam je regulisan dobrim delom adipokinetičkim neurohormonima koji učestvuju u obezbeđivanju dovoljne količine energije koja je potrebna za prevazilaženje ekstremnih uslova. Stres izaziva promene u lučenju egdizoregulatornih i alatoregulatornih neurohormona i modifikuje intenzitet sinteze egdizona i juvenilnih hormona u protorakalnoj žlezdi i corpora allata. Promene u količini egdizona i juvenilnog hormona u stresu povećavaju rizik početka vremenski neadekvatnih morfogenetskih promena u tkivima insekata. Stresom izazvane promene u količini morfogenetskih neurohormona su ograničene a i periodi osetljivosti ćelija na morfogenetske stimuluse se menjaju u stresu ograničavajući donekle mogućnost neadekvatnih morfogenetskih promena.nul

Characterization of trypsin-like enzymes from the midgut of Morimus funereus (Coleoptera: Cerambycidae) larvae

The pH along the midgut of M. funereus larvae had different values, being acidic in the anterior section and basic in the middle and posterior sections. Elastase- and chymotrypsin-like activities were highest in the middle, low in the anterior, and negligible in the posterior section of the midgut. Trypsin-like activities were detected along the whole midgut, with more than 90% of activity in the anterior section. The level of elastase- and chymotrypsin-like activity was very low compared to trypsin-like activity. In the anterior section of the midgut, two isoforms of trypsin-like enzymes were found, both being basic and almost completely inhibited by benzamidine

Influence of nutrient substrates on the expression of cellulases in Cerambyx cerdo L. (Coleoptera: Cerambycidae) larvae

The expression and distribution of digestive cellulases along the midgut of Cerambyx cerdo larvae were analyzed for the first time and are presented in this article. Four groups of larvae were examined: larvae developed in the wild; larvae taken from the wild and successively reared on an artificial diet based on polenta; and larvae hatched in the laboratory and reared on two different artificial diets. Seven endocellulase and seven β-D-glucosidase isoforms were detected in all midgut extracts of C. cerdo with a zymogram after native PAGE. We observed that C. cerdo larvae are capable of producing cellulase isoforms with different PAGE mobilities depending on the nutrient substrate. From our findings it can be assumed that, depending on the distribution of endocellulase and β-D-glucosidase, cellulose molecules are first fragmented in the anterior and middle midgut by endo-β-1,4-glucanase; subsequently, the obtained fragments are broken down by β-D-glucosidase mostly in middle midgut

Comparison of α-amylase isoforms from the midgut of Cerambyx cerdo L. (Coleoptera: Cerambycidae) larvae developed in the wild and on an artificial diet

α-Amylase isoforms of Cerambyx cerdo larvae from the wild (ML and SL) and reared in the laboratory (ADL) were compared. Three amylase isoforms were presented in the SL and ML extracts while two isoforms were presented in the ADL according to zymogram after isoelectric focusing (IEF). All C. cerdo amylase isoforms were acidic proteins (pI < 3.5). Seven amylase isoforms (ACC 1-7) from the midgut of C. cerdo larvae were found in the ML midgut extract, six in the SL extract, and four in the ADL extract according to native PAGE zymogram. The ADL amylase had the highest activity. All crude midgut extracts of C. cerdo larvae were fractionated on a Superose 12 HR column. The molecular mass of the ACC was estimated to be 34 kDa.Upoređene su izoforme α-amilaze larvi Cerambyx cerdo sakupljenih iz prirode (ML i SL) i gajenih na veštačkoj podlozi u laboratoriji (ADL). Zimogramskom detekcijom posle IEF-a po tri izoforme su detektovane u ML i SL ekstraktima, a u ADL dve izoforme. Sve amilazne izoforme iz C. cerdo su bile kisele (pI < 3.5). Zimogramskom detekcijom posle nativne elektroforeze sedam izoformi je detektovano u ML ekstraktu, šest u SL ekstraktu i četiri u ADL ekstraktu. Najveća amilazna aktivnost je detektovana u ADL ekstraktu. Svi ekstrakti srednjih creva larvi C. cerdo su frakcionisani na koloni Superose 12 HR. Molekulska masa ACC-a je bila 34 kDa.Projekat ministarstva br. 142026

Influence of nutrient substrates on the expression of cellulases in Cerambyx cerdo L. (Coleoptera: Cerambycidae) larvae

The expression and distribution of digestive cellulases along the midgut of Cerambyx cerdo larvae were analyzed for the first time and are presented in this article. Four groups of larvae were examined: larvae developed in the wild; larvae taken from the wild and successively reared on an artificial diet based on polenta; and larvae hatched in the laboratory and reared on two different artificial diets. Seven endocellulase and seven β-D-glucosidase isoforms were detected in all midgut extracts of C. cerdo with a zymogram after native PAGE. We observed that C. cerdo larvae are capable of producing cellulase isoforms with different PAGE mobilities depending on the nutrient substrate. From our findings it can be assumed that, depending on the distribution of endocellulase and β-D-glucosidase, cellulose molecules are first fragmented in the anterior and middle midgut by endo-β-1,4-glucanase; subsequently, the obtained fragments are broken down by β-D-glucosidase mostly in middle midgut.Projekat ministarstva br. 17204

Characterization of trypsin-like enzymes from the midgut of Morimus funereus (Coleoptera: Cerambycidae) larvae

The pH along the midgut of M. funereus larvae had different values, being acidic in the anterior section and basic in the middle and posterior sections. Elastase- and chymotrypsin-like activities were highest in the middle, low in the anterior, and negligible in the posterior section of the midgut. Trypsin-like activities were detected along the whole midgut, with more than 90% of activity in the anterior section. The level of elastase- and chymotrypsin-like activity was very low compared to trypsin-like activity. In the anterior section of the midgut, two isoforms of trypsin-like enzymes were found, both being basic and almost completely inhibited by benzamidine.pH vrednost duž srednjeg creva larvi M. funereus se razlikuje, kisela je u regionu prednjeg dela, dok je u srednjem i zadnjem delu bazna. Elastazama i himotripsinima slična aktivnost je najveća u srednjem delu srednjeg creva dok je u prednjem delu detektovana mala vrednost, a u zadnjem delu zanemarljiva. Tripsinima slična aktivnost je detektovana duž celog srednjeg creva, s tim da se više od 90 % aktivnosti detektuje u prednjem delu srednjeg creva. Zastupljenost elastazama i himotripsinima sličnih endopeptidaza je zanemarljivo mala u poređenju sa zastupljenošću tripsinima sličnih enzima. U prednjem delu srednjeg creva nalaze se dve izoforme tripsinima sličnih enzima, sa baznim pI vrednostima, koje su skoro u potpunosti inhibirane benzamidinom.Projekat ministarstva br. 142026

Comparison of α-amylase isoforms from the midgut of Cerambyx cerdo L. (Coleoptera: Cerambycidae) larvae developed in the wild and on an artificial diet

α-Amylase isoforms of Cerambyx cerdo larvae from the wild (ML and SL) and reared in the laboratory (ADL) were compared. Three amylase isoforms were presented in the SL and ML extracts while two isoforms were presented in the ADL according to zymogram after isoelectric focusing (IEF). All C. cerdo amylase isoforms were acidic proteins (pI < 3.5). Seven amylase isoforms (ACC 1-7) from the midgut of C. cerdo larvae were found in the ML midgut extract, six in the SL extract, and four in the ADL extract according to native PAGE zymogram. The ADL amylase had the highest activity. All crude midgut extracts of C. cerdo larvae were fractionated on a Superose 12 HR column. The molecular mass of the ACC was estimated to be 34 kDa.Upoređene su izoforme α-amilaze larvi Cerambyx cerdo sakupljenih iz prirode (ML i SL) i gajenih na veštačkoj podlozi u laboratoriji (ADL). Zimogramskom detekcijom posle IEF-a po tri izoforme su detektovane u ML i SL ekstraktima, a u ADL dve izoforme. Sve amilazne izoforme iz C. cerdo su bile kisele (pI < 3.5). Zimogramskom detekcijom posle nativne elektroforeze sedam izoformi je detektovano u ML ekstraktu, šest u SL ekstraktu i četiri u ADL ekstraktu. Najveća amilazna aktivnost je detektovana u ADL ekstraktu. Svi ekstrakti srednjih creva larvi C. cerdo su frakcionisani na koloni Superose 12 HR. Molekulska masa ACC-a je bila 34 kDa.Projekat ministarstva br. 142026

Influence of nutrient substrates on the expression of cellulases in Cerambyx cerdo L. (Coleoptera: Cerambycidae) larvae

The expression and distribution of digestive cellulases along the midgut of Cerambyx cerdo larvae were analyzed for the first time and are presented in this article. Four groups of larvae were examined: larvae developed in the wild; larvae taken from the wild and successively reared on an artificial diet based on polenta; and larvae hatched in the laboratory and reared on two different artificial diets. Seven endocellulase and seven β-D-glucosidase isoforms were detected in all midgut extracts of C. cerdo with a zymogram after native PAGE. We observed that C. cerdo larvae are capable of producing cellulase isoforms with different PAGE mobilities depending on the nutrient substrate. From our findings it can be assumed that, depending on the distribution of endocellulase and β-D-glucosidase, cellulose molecules are first fragmented in the anterior and middle midgut by endo-β-1,4-glucanase; subsequently, the obtained fragments are broken down by β-D-glucosidase mostly in middle midgut.Projekat ministarstva br. 17204

Effect of crude corpora cardiaca extracts on carbohydrate and lipid metabolism in larvae of the cerambycid beetle Morimus funereus as a function of diet and temperature

The effects of crude corpora cardiaca (CC) extracts on the changes in haemolymph trehalose and lipid concentrations in larvae of cerambycid beetle Morimus funereus were investigated as a function of diet and temperature. After injection of crude conspecific CC extracts, haemolymph trehalose concentrations were significantly increased in the last larval instar of M. funereus reared on artificial diet at 23 C. In M. funereus larvae. injected with crude brain extracts, haemolymph trehalose concentrations were increased by 15%, while glycogen concentrations were decreased by 17.5%. By injection of crude extracts of suboesophageal ganglion an increase was obtained in fat body glycogen concentrations. In larvae exposed to a stressful temperature of 13 degrees C for 90 min haemolymph trehalose and lipid concentrations were significantly decreased compared to control. By injection of crude CC extracts of adult M. funereus, haemolymph trehalose concentrations were significantly increased in beetle larvae fed on natural diet at a low temperature of 4 degrees C. A different efficiency of CC extracts of larvae and adult beetles was obtained as a function of temperature, the nutritive Value of the diet and the developmental stage. (C) 1999 Elsevier Science Inc. All rights reserved.nul

Effect of crude corpora cardiaca extracts on carbohydrate and lipid metabolism in larvae of the cerambycid beetle Morimus funereus as a function of diet and temperature

The effects of crude corpora cardiaca (CC) extracts on the changes in haemolymph trehalose and lipid concentrations in larvae of cerambycid beetle Morimus funereus were investigated as a function of diet and temperature. After injection of crude conspecific CC extracts, haemolymph trehalose concentrations were significantly increased in the last larval instar of M. funereus reared on artificial diet at 23 C. In M. funereus larvae. injected with crude brain extracts, haemolymph trehalose concentrations were increased by 15%, while glycogen concentrations were decreased by 17.5%. By injection of crude extracts of suboesophageal ganglion an increase was obtained in fat body glycogen concentrations. In larvae exposed to a stressful temperature of 13 degrees C for 90 min haemolymph trehalose and lipid concentrations were significantly decreased compared to control. By injection of crude CC extracts of adult M. funereus, haemolymph trehalose concentrations were significantly increased in beetle larvae fed on natural diet at a low temperature of 4 degrees C. A different efficiency of CC extracts of larvae and adult beetles was obtained as a function of temperature, the nutritive Value of the diet and the developmental stage. (C) 1999 Elsevier Science Inc. All rights reserved.nul