Left Colleterial Gland Research Articles

The formation of protocatechuic acid-4-O,β-glucoside in Periplaneta americana and the possible rôle of the juvenile hormone

The enzymatic synthesis of 4-O,β-glucoside from glucose and protocatechuic acid in different tissues of the adult female cockroach has been studied. Glucoside-synthesizing activity could be detected in the left colleterial gland as well as in the integument and fat body. The action of juvenile hormone on the biosynthesis of the P.A. glucoside is exerted in the biosynthetic chain leading from tyrosine to protocatechuic acid and not in the coupling of the acid with the glucose. It is suggested that the integument is the primary site for the biosynthesis of the glucoside in the animal.

Studies on insect fibrous proteins: the structural protein of the ootheca in the praying mantis, Sphodromatis centralis Rehn.

SUMMARYHistological studies have been made on the left colleterial gland which secretes the α‐type structural protein in the ootheca of Sphodromantis centralis. Three distinct types of secretory cell are present in the gland wall, and each has a complex apical ‘end‐apparatus’ composed of closely packed canalicules radiating from a central cavity. Structural protein is synthesized in the cytoplasm, passed through the canalicules into the cavity of the end‐apparatus, and extruded into the lumen as strongly birefringent, apparently membrane‐free globules. At this stage the globules consist of numerous concentric layers of long, parallel fibrils, 0·05–0·1 μm in diameter. In each successive layer the fibril direction is rotated through an angle of about 18° about an axis perpendicular to the layers, in the manner of cholesteric phase systems. When sectioned, the globules reveal a regular ‘lamellated’ structure similar to that apparent in sections of some insect and crustacean cuticles. A three‐dimensional model has been constructed to illustrate this phenomenon. During ootheca formation fibrils become transformed into thin ‘crystalline’ ribbons, about 15 μm long, 1–2 μm wide and 200–300 Å thick. Very regular diamond‐shaped ribbons may be obtained in vitro by mixing structural protein globules from dissected left glands with optimum concentrations (0·005–·025 m) of calcium chloride in unbuffered solution. Experiments suggest that calcium ions play an important part in the natural process of ribbon formation.

The function of the accessory sex glands in Periplaneta americana (L.). II. The role of the juvenile hormone in the synthesis of protein and protocatechuic acid glucoside

AbstractThe left colleterial gland, as part of the accessory sex glands of the adult female cockroach, produces a structural protein and the phenolic tanning agent, protocatechuic acid glucoside. Both are needed for the formation of the egg capsule (ootheca), which contains the eggs of the species. The synthesis of the two compounds is under the control of the corpus allatum hormone. Transplanted colleterial glands are able to synthesize protein and glucoside in adult females; in adult males, however, the transplanted glands are able to synthesize only protein. They do not synthesize glucoside, even under the influence of additional juvenile hormone supplied to the male hosts by injection. Yet males produce enough juvenile hormone to promote the synthesis of protein and glucoside by colleterial gland cultured in female hosts. This was demonstrated by combining in parabiotic fusion adult males with decapitated adult females. The adult female apparently contains a factor which in the presence of juvenile hormone is a prerequisite for glucoside but not for protein synthesis. This factor is apparently also absent in nymphs of both sexes. The dependence of protein synthesis on the juvenile hormone provides a quantitative bioassay for estimating the juvenile hormone titer in all postembryonic stages of development. At present, glucoside synthesis can only be used as an indicator for the juvenile hormone concentration of adult females of different ages. The juvenile hormone presumably acts directly on the tissues of the collecterial glands.This paper is dedicated to the memory of Professor Alfred Kühn, one of the great biologists of his time, who died in Tübingen, Germany on November 22, 1968.

The identification of [formula omitted] alcohol in teh left colleterial gland of Blaberus discoidalis

3- Hydroxy-4-O-β- d - glucosidobenzyl alcohol has been indentified in the left colleterial gland of the cockroach Blaberus discoidalis. Its aglucone is likely to be involved n the cross-linking of the protein of cockroach egg cases.

Left colleterial proteins in the viviparous cockroach Nauphoeta cinerea

Polyacrylamide disk electrophoresis of the left colleterial gland homogenates of Nauphoeta cinerea using β-alanine acetate as the buffer at pH 4·5 yielded eight positively charged protein fractions. The ‘front’ fraction seems to represent some tissue protein, and fractions 3 and 4, which have mobilities faster than those of the major proteins in the blood, appear to constitute the structural proteins of the oötheca. Tests on gland homogenates for bound non-protein constituents like nucleic acids, carbohydrates, and lipids were negative. The egg-case of Nauphoeta is incompletely stabilized and yields some soluble proteins even without hydrolysis. The accumulation of secretory proteins in the left colleterial gland is under the influence of the corpus allatum hormone and is not mediated through the ovary.

The Colleterial Glands of Cockroaches1

The 19 species whose colleterial glands were studied represent three types of egg-laying behavior—those that abandon the ootheca shortly after its formation, those that carry it externally during embryogenesis, and those that carry it internally. The glands vary in size from species to species according to the size of the ootheca elaborated. In Diploptera punctata they are not required during the development of the embryos in the uterus of the female, β -glucosidase is present in the right colleterial gland of cockroaches representing all three types of egg-laying behavior, and also in that of a praying mantis. An unidentified glucoside (Gl-A) was demonstrated by paper chromatography in extracts of the left colleterial glands of 19 species. This Gl-A occurs along with a glucoside of protocatechuic acid in seven species of the subfamily Blattinae; with a second unidentified glucoside (Gl-B) in two species, representing two genera, of Pseudomopinae. In nine other species, representing those that carry oothecae either externally or internally during embryogenesis, Gl-A is apparently the only precursor of the tanning agent. The β -glucoside of protocatechuic acid was found also in extracts of left colleterial glands of praying mantids and in extracts of accessory glands of the twolined grasshopper.

Calcium Oxalate in the Oothecae of Cockroaches

Calcium oxalate crystals were observed in the oothecae of 18 species of oviparous cockroaches, whereas no crystals were found in the oothecae of one oviparous species or in 8 species which carry their egg cases internally. According to X-ray diagrams calcium oxalate dihydrate is present in all genera with the exception of Ectobius in which the monohydratc occurs. Calcium oxalate constituted as much as 15 percent of the dry weight of the ootheca in Periplaneta americana and about 0.3 percent in Blattella germanica . Transplanation experiments indicated that the production of calcium oxalate is a specialized function of the cells of the left colleterial glands.

The electron microscopy of the left colleterial gland of the cockroach.

A study has been made of the cells of the left colleterial gland of the cockroach, Periplaneta americana (L.), using the electron microscope, and the results compared with previous histological and histochemical studies. The colleterial gland consists of an arborescent bunch of long tubules composed mainly of the cells which secrete the structural protein of the egg case ("type 4 cells"). Other types of cells: chitinogenic cells and "type 2 and 3 cells" each with a different cytology are described. The type 4 cells, which form the structural protein, reveal a cytological pattern very similar to that described for mammalian cells in a state of active protein synthesis. There is an elaborate development of particle-studded membranes in the cytoplasm. Smaller, rounded agranular vesicles also occur. The free secretory surface of the secreting cells forms the "end-apparatus" of the light microscopists. The invaginated surface is cast into numerous long narrow processes usually radially arranged and directed into a funnel-like formation derived from the thin intima lining the lumen of the gland (Text-fig. 2). The secretion in the form of small balls may be seen in the cavity of the end-apparatus and sometimes in the narrow processes. The small chitinogenic cells, lying between the protein-forming cells and the thin intima which they secrete, have a different cytology perhaps related to the fact that they form a polysaccharide rather than a protein. There is a very poor development of the particle-studded membranes of the type found in protein-forming cells. The type 2 cells, supposed to form an oxidase, have an end-apparatus that is similar to, but more complex than, those of the type 4 cells and their cytoplasm is almost completely filled with mitochondria. There is some evidence that mitochondria play a part in forming the oxidase and pass into the tubules of the end-apparatus. Type 3 cells resemble both types 2 and 4 and are probably a transient intermediate form.

The occurrence of protocatechuic acid and its 4-O-β- d-glucoside in Blatta and Periplaneta

(1) The left colleterial glands of two species of cockroach secrete a β-glucoside of protocatechuic acid, which can be identified readily by chromatography and ultra-violet spectroscopy. (2) The compound is identical with 4-O-β- d-glucosidoprotocatechuic acid synthesized from 3-O-acetylprotocatechuic acid and 2:3:4:6-tetra-O-acetyl- d-glucosyl-α-bromide. (3) The ultra-violet spectra of the synthetic and naturally occurring glucosides have been correlated with those of known substituted hydroxybenzoic acids.

Tissues for Assessing Histochemical Methods for Calcium

ABSTRACT An account is given of three tissues which are suitable for use as standard objects when attempting methods that are said to reveal calcium salts in tissues. The tissues are the digestive gland of the snail Helix, the gut diverticulum of the crab Carcinus, and the left colleterial gland of the cockroach Periplaneta. They contain respectively calcium carbonate, calcium phosphate, and calcium oxalate deposits. The deposits are little, if at all, contaminated with other calcium salts.

Observations on the mechanism of a tanning reaction in Periplaneta and Blatta

Certain aspects of the formation of the sclerotin walls of the oothecae of the cockroaches Blatta and Periplaneta are considered. The walls undergo a process of natural tanning, as a result of which their constituent substance, at first soft and colourless proteinaceotis material, is changed into a hard and inert sclerotin. The tanning agent is thought to be an ortho -quinone derived from protocatechuic acid. The material of which an ootheca is composed is largely derived from the secretions of the two colleterial glands. A method of analysis involving paper partition chromatography and absorption spectroscopy is described, by means of which it has been possible to determine the substances present in the glands and to elucidate the changes that occur when their secretions interact. It has been found that the left colleterial gland secretes the structural protein, a polyphenol oxidase and the 4- O - β -glucoside of protocatechuic acid, while the right gland secretes a β -glucosidase. When mixed in nature or under experimental conditions, the secretions interact and the β -glucosidase liberates protocatechuic acid from its β -glucoside. The resulting acid is then oxidized in the presence of the oxidase to a quinone which is believed to form cross-linkages between adjacent molecules of the structural protein giving the tanned product, sclerotin. In the light of this explanation of the sclerotization of the oothecal wall, earlier histochemical results are re-examined. This is thought to be the first report of the isolaticfn of a β -glucoside of protocatechuic acid from natural sources and of its participation in biological processes.

The Formation of the Ootheca by Periplaneta americana: II. The Structure and Function of the Left Colleterial Gland

ABSTRACT The anatomy of the left colleterial gland of the cockroach is described. It is convenient to subdivide the gland into four regions. At the posterior end, abutting on to the outlet of the gland, there is no secretory activity and the cells of this region are not unlike normal epidermal cells. Anterior to this region are the three secretory regions of the gland ; of these, the anterior and posterior secrete the structural protein and the constituent cells are equipped with a complex end-apparatus, a thick-walled depression in the apex of the cell in which the final stages of the elaboration of the secretion occur. The body of the end-apparatus contains canalicules which lead to the lumen of the gland. Alkaline phosphatase is abundantly present in this organ. Protein is secreted continuously, and there is no cycle related to oviposition. The third region, between the protein-secreting regions, secretes an oxidase, whose function may well be to oxidize the phenolic tannin-precursor produced in the right colleterial gland when the products of the two glands come together at oviposition. The gland becomes fully functional some 14 days after the final moult, the immature cells of the nymph developing directly into mature cells characteristic of the region in which they occur. Within each of the main regions the cells show some differences which suggest that there is a wave of change passing along the gland. It appears that the cells of the anterior end of the gland become defunct and the hitherto inactive cells of the posterior end take on a secretory function. The structural protein has a high phenolic content, and contains no combined carbohydrate. The presence of lipoid in the secretory cells appears to be directly bound up with the secretory processes.