Granular Hemocytes Research Articles

Lysozyme is stored in the granules of certain haemocyte types in Locusta

Lysozyme has been isolated from the serum of normal adult Locusta migratoria and antibodies were raised in rabbits against this molecule. Immunocytological techniques indicate that lysozyme is synthesized and stored in the two granular hemocyte types of this insect species: the typical granulocyte and the coagulocyte. The release of lysozyme appears to be associated with the process of coagulation.

Nocturnal rhabdom cycling and retinal hemocyte functions in crayfish (Procambarus) compound eyes. I. Light microscopy

AbstractIn addition to the previously known photoreceptor membrane cycle coupled to light and dark adaptation, detailed study of the late‐night period (24:00 to 06:00 h) in Procambarus compound eyes demonstrates that a second cycle of degradation (about 14% decrease in maximum rhabdom diameter) and resynthesis takes place completely in the dark between midnight and dawn.Invasive granular hemocytes are present in the retina throughout the latenight period in winter. Their distribution around the retinulas during the degradative phase (24:00 to 02:00 h) of the turnover cycle differs significantly from that characteristic of both the synthetic (02:00 to 04:00 h) and resting (04:00 to 06:00 h) phases. This correlation provides an important way of identifying retinal areas in the process of net photoreceptor membrane degradation. Retinal hemocytes are highly significantly more numerous in the resting stage than in either of the other two.Certain associated changes differ between winter and summer series. Total hemocyte numbers in our winter experiments show a positive linear correlation with rhabdom diameters. In the summer series, retinal hemocytes are rare or absent, and rhabdom diameters are significantly smaller than in winter. No hemocytes are associated with the smallest (June) rhabdoms. Yet the latter do show the late‐night breakdown and regeneration. Correlation between hemocyte numbers and rhabdom size becomes almost perfect if our summer and winter series are pooled.

Haemopoiesis in Lepidoptera. III. A note on the multiplication of spherule cells and granular haemocytes

Blood films from early sixth instar larvae of Euxoa declarata (Lepidoptera: Noctuidae) stained in hematoxylin – eosin – alcian blue showed unequivocal examples of mitosis in spherule cells. The improved visibility of mitosis and the estimation of the mitotic index from counts of dividing cells per 1000 cells of each type indicated a far greater potential maximum production of spherule cells and granular haemocytes by mitosis than reported previously. Certain other methods of staining showed similar clear examples of spherule cell mitosis.

Ultrastructural and histological study of degenerative changes leading to black gills in grass shrimp exposed to a dithiocarbamate biocide

Pathologic “milky” and brown-black gills of grass shrimp, Palaemonetes pugio, exposed to low levels (5 to 60 ppb) of a 50% potassium-dimethyldithiocarbamate biocide (Busan-85) for 14 days were studied using light and electron microscopy. In shrimp exposed to 5 ppb Busan-85, a gradation of degenerative changes could be ascertained both within the gills of individual shrimp and among the gills of different shrimp. Primary degenerative changes, first evident in the apical epithelium of the lamellar plates, included: swollen mitochondria, dilated rough endoplasmic reticulum, the appearance of a dense grainy material within the subcuticular spaces and of paracrystalline elements within the epithelial cytoplasm, the formation of autophagosomes, and a loss of membrane continuity. Granular hemocytes migrated into the subcuticular spaces and appeared to phagocytose the grainy material, while other hemocytes phagocytosed and encapsulated the pathological epithelium. Later, the lamellar tips became congested with numerous interdigitating hemocytes which formed a “plug.” A new epithelium, derived partly from mitosis of basal lamellar tissues, developed subjacent to the plug and contributed to the formation of an abnormal and sometimes perforated cuticle during premolt. At ecdysis, the hemocyte plugs in the apical region of the lamella were sloughed resulting in markedly truncated and swollen lamellae. This process of pathological lamellar reduction appears to be an important defense mechanism in response to branchial trauma caused by exposure to environmental contaminants.

Diurnal rhythm of hemocyte population in an insect,Schizodactylus monstrosus Drury

InSchizodactylus monstrosus the total hemocyte count appeared to be much lower during the day than at night. At night, the percentage of prohemocytes and spherule cells increased substantially over that of granular hemocytes, plasmatocytes and adipohemocytes. The percentage of sessile hemocytes was much higher during the day. Hemogram rhythmicity was much affected in decapitated insects; altered photoperiod had little effect on it.

An in vivo study of intracytoplasmic membranous structures associated with chronic stunt virus infection in granular hemocytes of Amyelois transitella

The fine structure of cytoplasmic, membranous structures associated with chronic stunt virus infection was studied in granular hemocytes of larvae of Amyelois transitella. Although nuclei of infected hemocytes apparently were not affected, viroplasmic bodies, the assumed sites of viral assembly, often filled the cytoplasm of these cells. Early stage viroplasmic bodies were bounded by single envelopes and contained finely granular, electron-dense viroplasms in which progeny virions formed aggregations or paracrystalline arrays. In mature viroplasmic bodies, viral aggregations and arrays were enveloped and segregated by multilayered membranous structures. Irregular, vesicular bodies occupied the electron-lucent areas between aggregations. Prior to cell lysis, membranous structures within viroplasmic bodies disintegrated in close association with secondary, membrane-bound bodies that were probably autophagic elements.

Dose-Mortality and Stunted Growth Responses of Larvae of the Navel Orangeworm, Amyelois transitella,12 Infected by Chronic Stunt Virus

Chronic stunt virus (CSV) is a small, isometric RNA virus that specifically invades granular hemocytes of the navel orangeworm, Amyelois transitella (Walker). Although CSV was highly pathogenic to 1st-instar larvae in laboratory tests, 3rd-instar larvae usually acquired chronic disease that was characterized by retarded growth and a prolonged period of moribundity. The LC50 for neonatal larvae challenged with surface applications of semipurified CSV was equivalent to 42 pg of larval homogenate per mm2. The slope of the calculated dosage-mortality regression was 0.75, which was indicative of the chronic nature of the disease. The rate of mortality was directly related to viral concentration. Weights and lengths of infected larvae exposed in the 3rd instar were inversely related to viral concentration and were significantly (P 0.05) after 10 days of exposure to virus, although many infected larvae survived as long as 40 days. Mature control larvae were ca. eightfold heavier and twofold longer than diseased larvae of comparable age.

A pathogenic nonoccluded virus in hemocytes of the navel orangeworm, Amyelois transitella (Pyralidae: Lepidoptera)

A small, nonoccluded virus was isolated from the granular hemocytes (=adipocytes) of moribund larvae of the navel orangeworm, Amyelois transitella, collected from almonds in northern California. The virus was readily transmitted perorally in laboratory tests and was highly pathogenic to neonate larvae; however, third- and fourth-stage larvae usually acquired attenuated infections that retarded growth and delayed mortality. Large paracrystalline viral arrays filled the cytoplasm of granular hemocytes of diseased larvae. Attempts to transmit the virus perorally to larvae of nine other species of moths were unsuccessful. The virus is isometric, about 25 nm in diameter, and contains single-stranded RNA. It has been designated “chronic stunt virus” (CSV) and tentatively assigned to the picorna-like viruses.

Comparison of concanavalin a-reactive determinants on hemocytes of two Biomphalaria glabrata snail stocks: receptor binding and redistribution

Fluorescein-labeled concanavalin A (F-Con A) was employed as a membrane probe to compare the surface glycosyl components associated with glass-adherent circulating hemocytes from a schistosome-susceptible (PR albino) and schistosome-refractory (10-R2) stock of snails Biomphalaria glabrata. Under hemolymph-free conditions, granular hemocytes (granulocytes), composed of two morphologically-distinct cell populations (rounded and spread hemocytes) bound F-Con A via specific carbohydrate surface receptors. Con A-binding induced in rounded hemocytes a redistribution (patching and capping) of lectin-receptor complexes. Receptor redistribution in both snail stocks was characterized by a high capping frequency (80–90% of adherent rounded cells) and temperature dependency. Differences in the response of albino and 10-R2 snail hemocytes to differing F-Con A concentrations, however, suggest that cells may possess subtle differences in physiology or function.

Hemocytes of Mosquito Larvae

Plasmatocytes, oenocytoids, and granular hemocytes inside the anal papillae of larval Culex tarsalis Coquillett, Psorophora ciliata (F.), Aedes aegypti (L.) and A. atlanticus Dyar and Knab were described following examinations by light and electron microscopy. Observation of these hemocytes is a convenient method of monitoring changes in hemocyte numbers in vivo.

Haemocytes associated with basement membrane of sex pheromone gland of Trichoplusia ni (Lepidoptera: Noctuidae). Ultrastructural observations

In female Trichoplusia ni, granular haemocytes are observed near the basement membrane of developing sex pheromone gland cells while plasmatocytes are observed near the basement membrane of unmodified epidermal cells. The basement membrane underlying gland cells is clearly different from that of other epidermal cells. There is a thin amorphous layer (layer 1) which is also present beneath unmodified cells, and a second layer (layer 2) apposing the haemocytes. Layer 2 is distinctly banded which results from tubules similar in dimensions and structural appearance to those observed within granules of the granular haemocytes. The observations indicate that the granules participate in the formation of layer 2 by emptying their contents into the haemocoel next to layer 1.

The individuality of plasmatocytes and granular hemocytes of arthropods — A review

The individuality of plasmatocytes and granular hemocytes of arthropods — A review

Cytochemistry of the very early stages of in situ coagulation in Calpodes ethlius (Lepidoptera)

Coagulation and phagocytosis are defence reactions which insects use in response to the introduction of foreign particles into their hemocoel. Coagulation occurs within 10 s of injection of latex beads and ink particles into a midfifth larval instar of Calpodes ethlius. A stringy, flocculent coagulum forms, trapping the particles and hemocytes. The hemocytes then go on to phagocytize the particles.The coagulum stains with alcian blue and lanthanum and dialyzed iron. The surface coat of granular hemocytes stains differently after coagulation has taken place with the same stains and with ruthenium red. There is no corresponding change in staining of the surface coat of plasmatocytes.

ÉTUDE DU COMPLEXE HÉMOCYTAIRE POSTEMBRYONNAIRE DE LAMBDINA FISCELLARIA FISCELLARIA (LEPIDOPTERA: GEOMETRIDAE)

AbstractHemocytes of Lambdina fiscellaria fiscellaria (Guen.) were examined as suspended cells or as slides from a culot. Five types of hemocytes were identified: prohemocytes, plasmatocytes, granular hemocytes, spherule cells, and oenocytoids. The low numbers of prohemocytes and oenocytoids, the significant decrease in the number of plasmatocytes in last larval stages, and the corresponding increase in granular and spherule cells have been compared with existent literature. Total hemocyte counts were also made.

Brain hormone carrier haemocytes in the moth Monema flavescens

The movement of neurosecretory substances released from the neurosecretory B cell in the pars intercerebralis to the haemolymph was examined with the progress of the termination of diapause in the slug moth pharate pupa, Monema flavescens. The injection of precipitates in the haemolymph of the pharate pupa just before the termination of diapause into diapausing pharate pupae reduced the numbers of days required for them to pupate. In the precipitates, seven types of haemocytes were present. The number of haemocytes, especially the granular cell, increased just before the termination of diapause. AF and CHP positive substances not detected in the haemocytes of diapausing pharate pupae appeared in the granular cells just before the termination of diapause. The period also coincided well with the releasing period of the neurosecretory B cell. Histological examination showed that granular haemocytes gathered around the pars intercerebralis at this period and exchange of neurosecretory substances occurred between granular haemocytes and neurosecretory B cells. Then granular haemocytes migrated to the region of the prothoracic gland. From digestion tests of the neurosecretory substances with rabbit serum and from the implantation tests of the neuroendocrine system, the substances detected in both the neurosecretory B cell and the granular haemocytes seemed to be the same. The dye injection caused a delay in larval-pupal ecdysis emergence. Droplets of black ink are incorporated into the granular haemocytes. This seems to be caused by blocking of the transport of neurosecretory substances released from cytoplasmic processes of the neurosecretory B cell. From these experiments, it is suggested that neurosecretory substances of the prothoracotropic hormone are transported to the prothoracic gland, along with granular haemocytes, after being released directly from the neurosecretory B cell to the haemolymph.

A comparative study of the morphology and behaviour of granular haemocytes of arthropods.

The characteristics of granular haemocytes of four non-insect arthropods were compared. The refractile, bacilliform granular inclusions dissolve in aqueous solutions of dyes. On glass slides, the cytoplasm of the haemocyte becomes distinctly separated into agranular ectoplasm with well developed filopodia and granular endoplasm. The mode of formation of vacuolar droplets together with the association of granules with them suggests secretory activity of the haemocytes. Fragmentation of cytoplasm or clasmatosis is common feature of granular haemocytes from prechilled animals. The significance of clasmatosis is discussed.The present study indicates that the plasmatocytes reported by previous workers may be the altered granular haemocytes. The characteristics of granular haemocytes of arthropods are compared with that of the granulocytes of molluscs.

Studies on the in vivo cellular reactions of insects: An ultrastructural analysis of nodule formation in Galleria mellonella

Cellular aggregates or nodules which formed in Galleria meltonella larvae in response to injections of killed Bacillus cereus were examined during their first 24 hr of development. The initial aggregation stage was very rapid, occurring within 1 min, and was brought about by the release of an adhesive flocculent material by granular haemocytes in contact with the bacteria. This material, which subsequently became increasingly electron dense owing to melanin deposition, consolidated and by 5 min ramified all the intercellular spaces. The granular cells degenerated, releasing portions of cytoplasm from their peripheries, and eventually appeared in the matrix as voids containing loosely flocculent material. No bacterial breakdown was seen, however. From 2–4 hr, plasmatocytes began to encapsulate the necrotic mass, and by 24 hr a complete sheath, composed of three discrete regions of cells, was formed. These findings are discussed in relation to the various proposed mechanisms of nodule and capsule formation.

The encapsulation of foreign tissue implants in Galleria mellonella larvae

When implanted into the haemocoel of the wax moth, Galleria mellonella, fragments of nerve cord from the locust Schistocerca gregaria were shown to be encapsulated by host haemocytes, in a two phase system. The initial reaction to the implant was observed within 5 min of implantation and involved the contact and lysis of the granular haemocytes on the nerve cord, and the release of granular material around it which resulted in localised clot formation. The second phase involved plasmatocyte adhesion to the implant ca. 30 min after its introduction into the haemocoel, but only at sites of granular cell lysis. These cells continued to be added to the capsule until 60 to 72 hr after implantation, and during this time granular release continued, although no further granular cell lysis occurred. The complete capsule (72 hr) could be divided into three distinct regions of cells showing various modifications from free plasmatocytes. It is suggested that encapsulation in this species involves some chemotactic element which originates from the granular cells and acts specifically on the plasmatocytes.

The cytology and cytochemistry of the hemocytes of Mytilus edulis and their responses to experimentally injected carbon particles

Hemocytes of Mytilus edulis were examined cytologically and cytochemically. On the basis of structure, staining reactions, and phagocytic behavior, they were divided into two main groups: basophilic hemocytes and eosinophilic granular hemocytes (granulocytes). The basophilic cells were further divided into small lymphocytes and larger phagocytic macrophages reactive for lysosomal hydrolases. Mitosis was observed in granulocytes and in small lymphoid cells, believed to be the stem cells for the basophilic cell line. A few cells appeared to be intermediate between lymphocytes and small granulocytes. Macrophages were the main cell type involved in the clearance of injected carbon particles. However, granulocytes did show some phagocytic activity. Brown cells displaying apparent amoebocytic behavior were found to contain Fe 3+ and Pb 2+ in cytoplasmic inclusions, some of which were also reactive for β-glucuronidase and glucosaminidase. These cells appear to have a separate origin from the hemocytes.

The cystacanth of Moniliformis moniliformis (Bremser, 1811) and its relationship with the haemocytes of the intermediate host (Periplaneta americana).

The nature of the capsule of the cystacanth of Moniliformis moniliformis was studied. Fat body, tracheal system, Malpighian tubules and haemocytes of the host are intimately associated with the cystacanth. The capsule of the cystacanth is cellular. The cells encapsulating the middle and late acanthellae are granular haemocytes of the host, whereas those encapsulating the cystacanth are agranular. Degranulation of haemocytes after encapsulation of the cystacanth recalls the common method for encapsulation of parasites of insect haemocytes, but a difference between the two kinds of encapsulation is that the capsule around the cystacanth does not bring about melanization nor destroys the parasite. It is suggested that the surface of the parasite may have inhibitors against enzyme systems causing melanization. Host haemocytes are also found in the capsular fluid. The infiltration of haemocytes into the capsule may be in response to the release of metabolites by the parasites. It is also suggested that the haemocytes may detoxify the parasitic metabolities. Rarely, capsules containing two parasites were observed. In one of the cases, one of the two cystacanths already possessed its own capsule. This finding, together with the cellular nature of the capsule, suggests that the capsule is of host origin.