Colleterial Gland Research Articles

Effect of validoxylamine A on the trehalase activity in the colleterial glands of the silkmoth, Bombyx mori

Effect of validoxylamine A on the trehalase activity in the colleterial glands of the silkmoth, Bombyx mori

Adhesive Strength of the glue substances in the Colleterial Glands of the Silkmoth, Bombyx mori

Adhesive Strength of the glue substances in the Colleterial Glands of the Silkmoth, Bombyx mori

RNA interference‐mediated knock‐down of Bla g 1 in the German cockroach, Blattella germanica L., implicates this allergen‐encoding gene in digestion and nutrient absorption

We used RNA interference (RNAi) to silence the expression of a gene encoding Bla g 1, a human allergen produced by the German cockroach, Blattella germanica L., to study its function in cockroach physiology. Females injected with 1 microg of double-stranded RNA contained 64% less Bla g 1 protein and Bla g 1 mRNA abundance was reduced by 91.4% compared to sham-injected females. Bla g 1 knockdown slowed the pace of weight gain, midgut growth, and colleterial gland and basal oocyte maturation, resulting in delayed egg case formation and lower fecundity. Exogenous juvenile hormone treatments rescued reproduction in RNAi-treated females, suggesting that Bla g 1 silencing lowered endogenous juvenile hormone, probably by reducing food intake and nutrient absorption.

Proteinaceous adhesive secretions from insects, and in particular the egg attachment glue of Opodiphthera sp. moths

Biochemical and electrophoretic screening of 29 adhesive secretions from Australian insects identified six types that appeared to consist largely of protein. Most were involved in terrestrial egg attachment. Hydrogel glues were subjected to gravimetric analyses and assessed for overall amino acid composition. When 32 proteins in glues from eight insect species were analyzed individually, many proved to be rich in Gly, Ser, and/or Pro, and some contained substantial levels of 4-hydroxyproline. A few proteins were heavily glycosylated. Abundant protein-based secretions were tested as adhesives, mainly by measuring dry shear strength on wood. The strongest (1-2 MPa) was an egg attachment glue produced by saturniid gum moths of the genus Opodiphthera. It was harvested from female colleterial gland reservoirs as a treacle-like liquid that underwent irreversible gelation, and recovered from the capsules of laid eggs as a highly elastic orange-brown hydrogel that could also display high tack. Its protein-based nature was confirmed and explored by spectroscopy, enzymatic degradation, and 2D gel electrophoresis. Its proteins are mostly 80-95 kDa, and sequences (almost all novel) were established for 23 tryptic peptides. Scanning probe microscopy of Opodiphthera hydrogel in water returned median values of 0.83 nN for adhesion, 63 kPa for modulus, and 87% for resilience. Recombinant mimics of this material might be useful as biodegradable commodity adhesives or as specialty biomedical products.

Colleterial glands of Sesamia nonagrioides as a source of the host‐recognition kairomone for the egg parasitoid Telenomus busseolae

Abstract The maize stemborer Sesamia nonagrioides glues its egg masses under the leaf sheaths or ear bracts using colleterial gland secretion. In spite of such concealed oviposition sites, these eggs are parasitized by Telenomus busseolae. The colleterial glands of S. nonagrioides are investigated as a possible source of the host‐recognition kairomone for T. busseolae. This secretion, applied on glass beads, elicits intense antennal drumming and oviposition probing behaviour in the parasitoid. Through an histochemical study, neutral and acid glycoconjugates are identified as components of the secretion. Finally, using ultrastructural techniques, the colleterial glands are described and classified as comprising class 3 secretory cells.

The fine structure of colleterial glands in two cockroaches and three termites, including a detailed study of Cryptocercus punctulatus (Blattaria, Cryptocercidae) and Mastotermes darwiniensis (Isoptera, Mastotermitidae)

The colleterial glands of insects are organs associated with the female genital apparatus. In cockroaches, these glands produce secretions that cover two parallel rows of eggs during oviposition, and in oviparous species, these secretions become the tanned, sculpted, rigid outer casing of the ootheca. The goal of this study was to compare the gross anatomy of the colleterial glands and the ultrastructure of their component tubules in the phylogenetically significant genera Cryptocercus (Blattaria) and Mastotermes (Isoptera). Recent studies indicate that cockroaches in the genus Cryptocercus are the sister group of termites, and Mastotermes is the only termite known to produce a cockroach-like ootheca. One additional oviparous cockroach, Therea, and two additional termites, Zootermopsis and Pseudacanthotermes, were also examined. As in other cockroaches, the colleterial glands of Cryptocercus and Therea are asymmetrical, with a well developed bipartite left gland and a smaller right gland. In the termites Mastotermes, Zootermopsis, and Pseudacanthotermes, the colleterial glands are composed of a well-developed, paired, anterior gland and a small posterior gland; histological staining and cytological evidence suggest that these are homologues of the left and the right colleterial glands of cockroaches, respectively. At the ultrastructural level, colleterial gland tubules are made of cells belonging to a modified class 1 type cell in the cockroaches, in Mastotermes, and in Zootermopsis; the latter lays its eggs singly, without a surrounding ootheca-like structure. In the advanced termite Pseudacanthotermes, the tubules are made of secretory units belonging to the class 3 cell type. This study demonstrates that the cytological characteristics of colleterial glands in basal termites are similar to those of cockroaches, whether the termite secretes an oothecal casing that covers two parallel rows of eggs, as in Mastotermes, or lays its eggs singly, as in Zootermopsis. The function of colleterial glands in non-mastotermitid termites is unknown.

Proteome analysis of the silkworm (Bombyx mori. L) colleterial gland during different development stages

The silkworm, Bombyx mori, colleterial gland developed very slowly until 2 days before emergence, then markedly enlarged due to the accumulation of a glue-like substances (mainly including 85% water and 11% proteins). However, the No glue (Ng) mutant female moth secreted only very little glue-like substance and laid loose eggs naturally. High-resolution two-dimensional polyacrylamide gel electrophoresis, followed by computer-assisted analysis, was used to screen the secretory region of colleterial gland protein patterns during different development stages to find quantitative and qualitative difference in protein expression during the pupae and moth stages. More than 700 protein spots were resolved in different developmental stages from the secretory region of the glands and most of the proteins were distributed in the mass range from 30 to 70 kD with pH 4-8. Through comparison and analysis, it was found that 3 proteins were only expressed in the later pupae stage (one or two days before emergence) and moth stage. Furthermore, these proteins were not expressed in the Ng mutant especially actin. There was a great variation of some protein expression volume during the development. Protein spots that changed more than 1.5-fold in expression level (relative to day 9), including 6 spots that were down-regulated and 2 spots that were up-regulated in expression were excised for identification by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Results indicated that actins that participated or regulated the exocytosis of colleterial gland and other differentially expressed proteins might be related to colleterial gland development or the secretion of a glue-like substance.

Multiple forms of arylalkylamine N-acetyltransferase (NAT) from cockroach female colleterial glands and activity changes during oocyte maturation

Arylalkylamine N-acetyltransferase (NAT) from the female colleterial glands of Periplaneta americana showed activity peaks at pH 6.0 and 9.5 and the pH profile changed during oogenesis. The left gland contained higher activity than the right gland but the right gland also contained recognizable activity. The patterns in activity change depended on the substrate used, tryptamine (TN) or serotonin (5-HT). When TN was used as the substrate, the alkaline peak was higher than the acidic peak. In contrast, when 5-HT was used, the acidic peak was much higher than the alkaline peak. This suggests that at least two NATs are present in this species that are specific to pH and substrate species. Of the four combinations of the two pH ranges and two substrate indolamines, the enzyme activity that showed a similar change to the oocyte maturation was obtained in the combination of pH 6.0 and TN. TN was actually detected in the colleterial glands by fluorescent measurements according to Hess and Uderfriend [J. Pharmacol. Exp., 127 (1959) 175–177]. It peaked on the 6th day of emergence, which corresponded to the first rise of oocyte length and yolk accumulation, whereas a small peak appeared in the phase of the second rise. TN, or more likely N-acetyl TN, may therefore be involved in the regulation of oocyte maturation which could be a novel mechanism in oocyte maturation.

Alkaline phosphatase activity in whitefly salivary glands and saliva.

Alkaline phosphatase activity was histochemically localized in adult whiteflies (Bemisia tabaci B biotype, syn. B. argentifolii) with a chromogenic substrate (5-bromo-4-chloro-3-indolylphosphate) and a fluorogenic substrate (ELF-97). The greatest amount of staining was in the basal regions of adult salivary glands with additional activity traced into the connecting salivary ducts. Other tissues that had alkaline phosphatase activity were the accessory salivary glands, the midgut, the portion of the ovariole surrounding the terminal oocyte, and the colleterial gland. Whitefly nymphs had activity in salivary ducts, whereas activity was not detected in two aphid species (Rhodobium porosum and Aphis gossypii). Whitefly diet (15% sucrose) was collected from whitefly feeding chambers and found to have alkaline phosphatase activity, indicating the enzyme was secreted in saliva. Further studies with salivary alkaline phosphatase collected from diet indicated that the enzyme had a pH optimum of 10.4 and was inhibited by 1 mM cysteine and to a lesser extent 1 mM histidine. Dithiothreitol, inorganic phosphate, and ethylenediaminetetraacetic acid (EDTA) also inhibited activity, whereas levamisole only partially inhibited salivary alkaline phosphatase. The enzyme was heat tolerant and retained approximately 50% activity after a 1-h treatment at 65 degrees C. The amount of alkaline phosphatase activity secreted by whiteflies increased under conditions that stimulate increased feeding. These observations indicate alkaline phosphatase may play a role during whitefly feeding.

Effects of ovariectomy and mating on the activity of the corpora allata in adult female Blattella germanica (L.) (Dictyoptera: Blattellidae)

Summary In adult female cockroaches, the ovary greatly affects the synthesis of Juvenile Hormone (JH) by the corpora allata, and in females of some cockroach species, removal of the ovaries results in a permanent depression of JH synthesis. We report that the corpora allata in ovariectomised, adult virgins of the German cockroach, Blattella germanica (L.), increase and then decrease in activity, as they do in intact females. Moreover, the distal tubules in the left colleterial glands of ovariectomised females accumulate abundant protein, the production of which is regulated by JH. In both ovariectomised and sham-operated females, the activity of the corpora allata more than tripled between days 1 and 4 of adulthood, during which the oocytes of sham-operated females grew considerably in length. The corpora allata of sham-operated females produced even more JH on day 7, but very little on day 10, by which time all females had oviposited. The glands of ovariectomised females, by constrast, produced a similar amount of JH on day 7 as on day 4, but much less on day 10. Beginning on day 13, the activity of the corpora allata increased again in ovariectomised females, an increase that did not occur until day 22 in sham-operated females. Mating of ovariectomised females on day 6 resulted in a significant increase in the activity of the corpora allata by day 10. We conclude that both the ovary and mating stimulate the synthesis of JH early in the reproductive cycle, but that neither is needed for the occurrence of a complete cycle of JH synthesis.

Reproductive morphology, copulation, and inter-populational variation in the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Copulatory mechanisms and internal reproductive systems of male and female Plutella xylostella (L.) were investigated. Both male and female specimens exhibited characteristics typical of ditrysian Lepidoptera, with some peculiarities. Female structures appear to be relatively simple: the bursa copulatrix lacks cuticular signa within, the spermatheca lacks lagenar arms exhibited in some Lepidoptera, and colleterial glands have secretory system and reservoir combined. Male accessory gland ducts are joined distally, a condition that has not been described in other Lepidoptera. Genitalia of both sexes appear simple; females possess a posterior cuticular extension of abdominal sternites that houses the bursal duct and accomodates the needle-like aedeagus of a male during copulation. Despite the apparent simplicity, configuration of genitalia is highly specific in shape, angle, and size, which is likely to be important in maintaining reproductive isolation within the species. However, a population of P. xylostella from Australia showed some modification to both aedeagal and bursal structures. These variations suggest some important implications for considering species with worldwide distributions.

Hormonal Control of Courtship Behavior and Reproductive Cycle in the Cockroach Species Blaptica dubia (Blattoidea: Blaberoidea: Blaberidae)

Blaptica dubia (Serville 1839) was reared at 26°C ± 2° with a 12 :12 L/D photoperiod. Under these conditions mating was first detected 5± 2 days after imaginal ecdysis. The pregnancy of this ovoviviparous cockroach lasts 48 - 64 days. Neuroendocrine and other humoral factors (juvenile hormone [JH]) stimulate oocyte growth, the activity of colleterial glands, and receptivity of FF. The ovulation of the 1rst gonotropic cycle occurs on d-17 (±3) after adult ecdysis. This period is correlated with high activity of corpora allata [CA] and corpora cardiaca [CC]. Thereafter and throughout most of pregnancy, the CA are generally inactive, rising in size again shortly before oviposition in association with the second gonotropic cycle. Allatectomy as well as cauterization of the median neurosecretory cells [m.ns.c]or decapitation prevent receptivity of the FF, mating behavior and oocyte maturation. Implantation of the retrocerebral complex and/or JH injections cancel the inhibition. The inhibitory influence of the extirpations depends on their timing during the reproductive cycle.

Characterization of a cDNA encoding a cytosolic peptidylprolyl cis-trans-isomerase from Blattella germanica.

Cyclophilins are an abundant and ubiquitous class of proteins first identified by their high affinity for the immunosuppressive drug cyclosporin A. Cyclophilins have peptidylprolyl cis/trans-isomerase activity in vitro, and thus may be involved in protein folding and trafficking in vivo. In this study, we report the cloning and characterization of a Blattella germanica cyclophilin cDNA. Analysis of this 846-bp cDNA reveals an open reading frame coding for a polypeptide of 164 amino acid residues with a molecular mass of 17934 Da. This B. germanica cyclophilin shares a central peptidylprolyl cis/trans-isomerase and a cyclosporin-A-binding domain with other cyclophilin sequences. The B. germanica cyclophilin amino acid sequence shares 83% identity with the cytosolic cyclophilin isoform from Drosophila melanogaster (Cyp-1). This identity suggests that B. germanica cyclophilin is a member of the cytosolic cyclophilin A (CyPA) family. From the alignment of cyclophilin sequences, we have found that 62 residues (positional identity of 40%) have remained invariant in eukaryotes for more than 1 billion years of divergence. We calculated a unit evolutionary period of 30.9 million years for the cytosolic isoform. Northern-blot analyses show that B. germanica CyPA mRNA is abundant, and present in all insect organs tested. The highest values for B. germanica cyclophilin mRNA tissue content were found in 6-day-old ovary, followed by brain, testis, and gut (15-30% the content of ovary). The muscle, fat body, and colleterial gland contained the lowest cyclophilin mRNA level (1-5% the content of ovary). There is a developmental pattern of gene expression affecting the embryo stages. These results suggest that this ubiquitously expressed B. germanica cyclophilin is subject to a differential regulation in tissues and during development. Southern-blot analysis of B. germanica DNA shows that only one copy of the CyPA gene is present per genome, whereas at least 20 genes or pseudogenes were detected in the mammalian genome.

Octopaminergic dorsal unpaired median (DUM) neurones innervating the colleterial glands of the female cockroach Periplaneta americana

The musculature of the colleterial glands receives innervation from branch 4B4a of the nerves designated 4B, which arise from the posterior part of the terminal abdominal ganglion in the female cockroach Periplaneta americana (L). Using Methylene Blue staining, the gross anatomy of the colleterial gland innervation has been described. Cobalt backfilling via branch 4B4 of nerve 4B revealed about 21 dorsal unpaired median (DUM) neurones located on both median and posterior parts of the terminal abdominal ganglion. Octopamine immunohistochemistry has shown that at least 15 octopamine-immunoreactive DUM neurones from median and posterior groups projected via branch 4B4a to the left and right colleterial glands. These data, together with results reporting the presence of octopamine-immunoreactive branches supplying these colleterial glands, make octopaminergic DUM neurones suitable candidates to modulate the muscle activity of the colleterial glands in female Periplaneta americana.

Colleterectomy and its impact on some reproductive behaviour of the tropical Tasar silk moth,Antheraea mylittaDrury (Lepidoptera: Saturniidae)

Summary Morphometry of the colleterial gland and its removal (colleterectomy) were made to observe its effect on egg laying and hatching behaviour in the female Tasar silk moth, Antheraea mylitta D. during three study season. The paired colleterial gland, which is divided into two distinct regions, was found to be attached at the terminal part of a common oviduct and secretes an adhesive substance which pastes the eggs to the substratum during oviposition. Colleterectomy of the female Tasar moth just after mating and thereby removal of the gluing material induced the deposition of loose white eggs and enhanced egg laying capacity and hatching efficiency followed by a shorter incubation period without any adverse effect on the progeny. No marked changes were observed in hatching initiation and duration. Further the overall pattern of egg laying was observed continuously for 3 consecutive days in each brood of control females, while the total egg hatchability was recorded for 3 consecutive days in the first...

Cytochrome c oxidase subunit I from the cockroach Blattella germanica: Cloning, developmental pattern and tissue expression

The nucleotide sequence of a cDNA corresponding to the transcription product of the mitochondrial structural gene cytochrome c oxidase subunit I was determined. A polypeptide of 508 residues was deduced from the reading frame established by the nucleotide sequence. TGA codes tryptophan, as in most other mitochondrial systems. From the comparison of the amino acid sequence of the putative Blattella germanica cytochrome c oxidase with those of Drosophila, we conclude that ATA and AGA codons specify methionine and serine respectively, instead of isoleucine and arginine. The sequence proposed for cytochrome c oxidase subunit I of B. germanica is largely homologous to that of other species. From the alignment of cytochrome c oxidase subunit I protein sequences we have found that 125 residues (positional identity of 22.3%) have remained invariant in this enzyme for more than one billion years of divergence. There is a developmental pattern of gene expression affecting the embryo stages. Northern blot analysis of RNA samples from different adult female tissues shows high cytochrome c oxidase subunit I mRNA levels in gut and fat body, and lower levels in ovary and colleterial glands.

Effect of juvenile hormone and moulting hormone on in vitro DNA synthesis in the left colleterial gland of Periplaneta americana

1. 1. The effect of juvenile hormone III and 20-hydroxyecdysone on in vitro DNA synthesis in the left colleterial gland of Periplaneta americana was compared. 2. 2. JH III reduced tritiated thymidine incorporation into the DNA of left colleterial glands obtained from females at stages 6 and 7 significantly ( P < 0.05 and < 0.005 respectively), and slightly at stage 6 (2 > P > 0.05), whereas 20-hydroxyeedysone caused an apparent increased in tritiated thymidine incorporation into the DNA of stage 7 glands ( P < 0.001). 3. 3. The effect of JH III was also demonstrated by labelling DNA with phosphorus-32.

In vitro DNA synthesis in the left colleterial gland of periplaneta americana from different stages of the reproductive cycle

1. 1. In viro DNA synthesis in the left colleterial gland of the cockroach Periplaneta americana from different stages of the reproductive cycle was compared. 2. 2. 3H-thymidine incorporation into TCA insoluble material by LCG DNA varied at different stages of the reproductive cycle. 3. 3. Labelling of DNA with phosphorus-32, followed by electrophoresis of restriction enzyme digested DNA, showed that total genomic DNA was labelled. 4. 4. Tissue autoradiography of 3H-thymidine labelled colleterial gland and fat body revealed that the incorporation was specific to the nuclei of the gland and not of the fat body. Nucleoli showed no labelling. 5. 5. Cytological analysis suggested that the LCG has polytene nuclei.

Juvenile hormone regulation of the left colleterial gland in intact and ovariectomized Blattella germanica (L.) (Dictyoptera: Blattellidae)

The left colleterial glands of intact and ovariectomized females were shown to accumulate protein in response to juvenile hormone III. Their distal tubule diameter was highly correlated with their protein content. While intact females excreted the oöthecal proteins to produce an egg case, ovariectomized females retained these proteins without apparent loss from the gland. In overiectomized females the colleterial gland therefore became larger and contained more protein than in intact females. The size and protein content of the left colleterial gland of ovariectomized females were arrested after the insects were allatectomized, and both were induced by injections of synthetic juvenile hormone III. Thus, the left colleterial gland can be used as a cumulative record of circulating juvenile hormone within an individual ovariectomized female, much as the basal oöcytes are used in intact females, and it can be used to distinguish betwen females that had increased juvenile hormone synthesis and those that had not.

On the latency and nature of phenoloxidase present in the left colleterial gland of the cockroach Periplaneta americana

The phenoloxidase system responsible for the sclerotization of cockroach ootheca is found to be present as an inactive form in the left colleterial gland of Periplaneta americana. The supernatant fraction obtained by centrifugation of the milky white secretions contained the inactive phenoloxidase which required both sodium dodecyl sulfate (SDS) and the insoluble sediment for exhibiting enzyme activity. Bovine serum albumin could replace the sediment in the activation process. Proteins separated from the supernatant fraction by molecular sieve chromatography on Sephadex G-25 did not require either albumin or the sediment, but required SDS for exhibiting the phenoloxidase activity. Among the detergents tested, SDS (anionic) and cetylpyridinium chloride (cationic) activated the phenoloxidase, but CHAPS (zwitterionic) or nonionic detergents failed to activate the enzyme. The activation caused by SDS occurred well below the critical micellar concentration of SDS indicating that SDS is causing the activation by binding to the protein and altering its conformation. Chloroform-methanol extracts of vestibulum or right gland could replace SDS confirming the presence of endogenous activator(s) of phenoloxidase system. A variety of exogenously added lipids could activate the latent enzyme, among which linoleate, oleate, laurate, linolenate, phosphatidylethanolamine, and phosphatidylglycerol proved to be the effective activators of the latent phenoloxidase. Partially purified phenoloxidase was found to be extremely labile and lost its activity on a) freezing and thawing, b) dialysis, and c) heating for 10 min at 55 degrees C. It exhibited a pH optimum of 7 and was inhibited drastically by phenylthiourea and diethyldithiocarbamate. It readily oxidized a number of o-diphenols such as 3,4-dihydroxybenzylalcohol, 3,4-dihydroxyphenethyl alcohol, catechol, N-acetyldopamine, N-acetylnorepinephrine, dopa, dopamine, etc., but failed to oxidize both 3,4-dihydroxybenzoic acid and 3,4-dihydroxybenzaldehyde. It neither converted the typical laccase substrate syringaldazine to its quinone methide product, nor oxidized the p-diphenols, hydroquinone and methylhydroquinone. Therefore, the enzyme participating in the quinone tanning of cockroach ootheca appears to be a typical o-diphenol oxidase and not a laccase as previously thought.