Hemocytes ultrastructure of Aedes aegypti (Diptera: Culicidae)

Mosquitoes have an efficient defence system against infection. Insect blood cells (hemocytes) play an essential role in defense against parasites and other pathogenic organisms that infect insects. We have identified by light and transmission electron microscopy six hemocytes cell types from the hemolymph of Aedes aegypti. They were: prohemocytes (20%), adipohemocytes (29%), granulocytes (16%), plasmatocytes (27%), oenocytoids (7%) and thrombocytoids (0.9%). The prohemocytes were the smallest hemocytes found in the hemolymph. Its cytoplasm occupies only a narrow area around the nucleus. The adipohemocytes were the most abundant cell type presented. These hemocytes exhibited a large lipid like vesicle and mitochondria. In electron micrographs, the granulocytes showed cytoplasm containing dilated rough endoplasmic reticulum (RER) and a round or elongated mitochondria. Electron-dense granules with a proteinaceous material were also present. The plasmatocytes were polymorphic and exhibited plasma membrane with irregular processes, philopodia and pseudopodia. Ultrastructural investigation revealed that the reticular cytoplasm showed a well-developed RER, a Golgi and vacuoles. Oenocytoids showed homogeneous cytoplasm with many mitochondria and ribosomes are scattered throughout the cytoplasm, abundant RER and a small smooth endoplasmic reticulum (SER) present at the cell poles. Thrombocytoids were very fragile and few in number. Similar characteristics were found in oenocytoids, possessing a homogeneous cytoplasm with poorly developed organelles, few mitochondria and granules.     

Phagocytosis of latex beads and bacteria by hemocytes of the triatomine bug Rhodnius prolixus (Hemiptera: Reduvidae)

Insect circulating hemocytes are primarily responsible for the immune defense against parasites and pathogens. Here, we have analyzed phagocytosis of both biotic (bacteria) and abiotic (latex) particles by circulating hemocytes of 5th-instar nymphs of the triatomine bug Rhodnius prolixus. The following hemocyte types were identified: prohemocytes, plasmatocytes, granulocytes, oenocytoids and adipohemocytes. There was a considerable change in the relative percentage of plasmatocytes and prohemocytes in the hemolymph after challenge with both latex beads and bacteria. Granulocytes and oenocytoids also change their relative percentage in response to latex bead and Staphylococcus aureus, respectively. No significant change was observed in adipohemocytes at any time or treatment. Our data demonstrated that plasmatocytes were the only cell type involved in phagocytosis of foreign particles. As in mammal cells, phagocytosis by both zipper and trigger mechanisms were observed for the uptake of latex beads and bacteria. Neither melanization nor micro-aggregation was observed towards latex particles or Escherichia coli. On the other hand, R. prolixus produced a strong melanization reaction against S. aureus, thus showing that differences exist in the responses to E. coli and to S. aureus. Ultrastructural changes observed in plasmatocytes, adipohemocytes and oenocytoids suggest that these hemocyte types are directly involved in the immune defense of R. prolixus against foreign particles.     

Effect of sweet flag rhizome oil (Acorus calamus) on hemogram and ultrastructure of hemocytes of the tobacco armyworm, Spodoptera litura (Lepidoptera: Noctuidae)

Effect of the essential oil of Acorus calamus L. rhizomes, was studied on hemocytes of the tobacco armyworm, Spodoptera litura. The oil was administered in oral application at concentration of 500 and 1000 ppm to last instar larvae of S. litura and its effect on ultrastructure of hemocytes and hemogram was evaluated. The oil was administered in topical application at 250 microg dose to pupae to ascertain its effect on total and differential hemocyte counts. At both scanning (SEM) and transmission electron microscopic (TEM) levels, the major effect of oil treatment was observed on plasmatocytes (PLs) and granular hemocytes (GRs). SEM study revealed that the cytoplasmic projections of granular hemocytes were reduced, while the filopods of plasmatocytes remained unaffected. The vacuolization in the cytoplasm and degeneration of the organelles in both plasmatocytes and granular hemocytes was observed by TEM. However, no such deformities were observed in prohemocytes (PRs), spherulocytes (SPs), and oenocytoids (OEs). A concentration-dependent decrease has been observed in the larval body weight and hemolymph volume (HV), 24-72 h after treatment. In comparison to the controls, the maximum percentage growth inhibition (GI) was recorded to be 58.28 and 66.48, respectively at 500 and 1000 ppm after 72 h treatment. Similarly after 72 h treatment, the percentage reduction in hemolymph volume was 61.38 and 69.05, respectively at 500 and 1000 ppm. Total hemocyte count (THC), in larvae computed from five recorded hemocyte types viz. PRs, PLs, GRs, SPs and OEs, decreased only after 48-72 h of treatment. The maximum decrease in THC was recorded to be 29.15 and 49.05% at 500 and 1000 ppm, respectively, after 72 h of treatment. There was continuous decline in THC in pupae after 24-72 h treatment. DHC study revealed that both the concentrations of oil in 6th instar larvae of S. litura caused a decrease in PRs, PLs and SPs and increase in GRs and OEs after 24-72 h of treatment. Since A. calamus oil treatment causes the injury to both PLs and GRs and also affects the hemogram, it can be inferred that cellular defence reactions of S. litura are impaired.     

Circulating hemocytes from larvae of Melipona scutellaris (Hymenoptera,Apidae, Meliponini): Cell types and their role in phagocytosis

Infection in insects stimulates a complex defensive response. Recognition of pathogens may be accomplished by plasma or hemocyte proteins that bind specifically to bacterial or fungal polysaccharides. Several morphologically distinct hemocyte cell types cooperate in the immune response. Hemocytes attach to invading organisms and then isolate them by phagocytosis, by trapping them in hemocyte aggregates called nodules, or by forming an organized multicellular capsule around large parasites. In the current investigation the cellular in the hemolymph third instar larvae of M. scutellaris has been characterized by means of light microscopy analysis and phagocytosis assays were performed in vivo by injection of 0.5 μm fluorescence beads in order to identify the hemocyte types involved in phagocytosis. Four morphotypes of circulating hemocytes were found in 3rd instar larvae: prohemocytes, plasmatocytes, granulocytes and oenocytoids. The results presented plasmatocytes and granulocytes involved in phagocytic response of foreign particles in 3rd instar larvae of M. scutellaris.     

Circulating hemocytes from larvae and adults of Carabus (Chaetocarabus) lefebvrei Dejean 1826 (Coleoptera, Carabidae): cell types and their role in phagocytosis after in vivo artificial non-self-challenge

Carabus lefebvrei Dejean 1826 is an helicophagous Italian endemic ground beetle that lives in central and south Apennines mountain forests, from lower altitudes to about 1500 m. In ground beetles, no morphofunctional data about immune system is available, even though they are well known both taxonomically and ecologically and they have been often used as indicators of the habitat quality due to their specificity to certain habitat types. In the current investigation the cellular population in the hemolymph of adult and third instar larvae of C. lefebvrei has been characterized by means of light and electron microscopy analysis and phagocytosis assays were performed in vivo by injection of 0.9 microm carboxylate-modified polystyrene latex beads in order to identify the hemocyte types involved in phagocytosis. Four morphotypes of circulating hemocytes were found both in larvae and in adults: prohemocytes, granulocytes, oenocytoids and plasmatocytes. After in vivo artificial non-self-challenge treatments, C. lefebvrei showed a non-specific immune response involving phagocytosis performed by plasmatocytes, both in adults and in larvae and by oenocitoids in larvae. In untreated animals, the hemocyte type presenting a firm phagocytic activity, the plasmatocytes, presented a percentage significantly higher in larvae than in adults, and after latex beads injections in larvae there was a tendency of significant difference in plasmatocyte percentage compared to controls injected with phosphate saline buffer. We think that these differences could be correlated with the peculiar morphology (less chitinization) and ecology of larval stages that are more sensitive to pathogens than adults.     

Morphological characterization via light and electron microscopy of Atlantic jackknife clam (Ensis directus) hemocytes

The Atlantic jackknife clam, Ensis directus, is currently being researched as a potential species for aquaculture operations in Maine. The goal of this study was to describe the hemocytes of this species for the first time and provide a morphological classification scheme. We viewed hemocytes under light microscopy (using Hemacolor, neutral red, and Pappenheim’s stains) as well as transmission electron microscopy (TEM). The 2 main types of hemocytes found were granulocytes and hyalinocytes (agranular cells). The granulocytes were subdivided into large and small granulocytes while the hyalinocytes were subdivided into large and small hyalinocytes. The large hemocytes had both a larger diameter and smaller nucleus to cell diameter ratio than their smaller counterparts. A rare cell type, the vesicular cell, was also observed and it possessed many vesicles but few or no granules. Using TEM, granulocytes were found to contain both electron-lucent and electron-dense granules of various sizes. These numerous granules were the only structures that took up the neutral red stain. Hyalinocytes had few of these granules relative to granulocytes. Large hyalinocytes had both various organelles and large vesicles in their abundant cytoplasm while small hyalinocytes had little room for organelles in their scant cytoplasm. Total hemocyte counts averaged 1.96 × 10⁶ cells mL⁻¹ while differential hemocyte counts averaged 11% for small hyalinocytes, 12% for large hyalinocytes, 59% for small granulocytes, and 18% for large granulocytes. The results of this study provide a starting point for future studies on E. directus immune function.     

Morphological characterization of hemocytes from Biomphalaria glabrata and Biomphalaria straminea

Biomphalaria glabrata and Biomphalaria straminea have been identified as intermediate hosts for Schistosoma mansoni. Several studies have found two cell types in the hemolymph of B. glabrata (hyalinocytes and granulocytes). However, there are no studies describing the hemocytes of B. straminea. With the aim of further describing the hemocyte subsets in B. glabrata and B. straminea, we conducted a detailed study using optical microscopy and transmission electron microscopy. Based on the morphological characteristics of the cells, we identified the same types of hemocytes in two species of molluscs, namely: blast-like cells, granulocytes, type I hyalinocytes, type II hyalinocytes and type III hyalinocytes. Blast-like cells had a spherical profile with a central nucleus filling almost the whole cell. Granulocytes were characterized by presenting variable numbers of granules. Type I hyalinocytes were the most abundant cell type and displayed various cytoplasmic projections. Type II and type III hyalinocytes had never previously been reported. They were few in number and were characterized by having an eccentric nucleus. From these results, it is concluded that there are five types of cells in the hemolymph of B. glabrata and B. straminea. Further studies are now needed to identify the role of these hemocytes in the immune response of these snails.     

Ultrastructural and functional characterization of circulating hemocytes from the freshwater crayfish Astacus leptodactylus: cell types and their role after in vivo artificial non-self challenge

The freshwater crayfish Astacus leptodactylus (Eschscholtz, 1823) is an important aquacultured decapod species as well as an invasive species in some European countries. In the current investigation we characterized the different classes of circulating blood cells in A. leptodactylus by means of light and electron microscopy analysis and we explored their reaction to different latex beads particles in vivo by total and differential cell counts at 0.5, 1, 2 and 4h after injections. We identified hemocytes by granule size morphometry as hyaline hemocytes with no or rare tiny granules, small granule hemocytes, unimodal medium diameter granule hemocytes and both small and large granule containing hemocytes. The latter granular hemocytes showed the strongest phenoloxidase l-DOPA reactivity both in granules and cytoplasm. A. leptodactylus respond to foreign particles with strong cellular immune responses. All treatments elicited a total hemocyte increase with a conspicuous recruitment of large granule containing hemocytes. All hemocyte types mounted some phagocytic response but the small granule hemocytes were the only ones involved in phagocytic response to all foreign particles with the highest percentages. These results (1) depict the variability in decapod hemocyte functional morphology; (2) identify the small granule hemocyte as the major phagocytic cell; (3) suggest that the rather rapid recruitment of large granule hemocyte in all treatments plays a relevant role by this hemocyte type in defense against foreign particles, probably in nodule formation.     

Female reproductive system of the sugarcane spittlebug Mahanarva fimbriolata (Auchenorrhyncha): vitellogenesis dynamics and protein quantification

The present study aimed describing the ovaries of the sugarcane spittlebug Mahanarva fimbriolata which are meroistic telotrophic with nurse cells and oocytes located in the tropharium. SEM revealed paired ovaries located dorsolaterally around the intestine, and oocytes exhibiting shapes ranging from round (less developed) to elliptic (more developed), suggesting a simultaneous, although, asynchronous development. Based on histological data we classified the oocytes in stages from I to V. Stage I oocytes exhibit follicular epithelium with cubic and/or prismatic cells, fine cytoplasmic granules. Stage II oocytes present intercellular spaces in the follicular epithelium due to the incorporation of yolk elements from the hemolymph. Small granules are present in the periphery of oocytes while larger granules are observed in the center. Stage III oocytes are larger and intercellular spaces in the follicular epithelium are evident, as well as the interface between follicular epithelium and oocyte. Yolk granules of different sizes are present in the cytoplasm. During this stage, chorion deposition initiates. Stage IV oocytes exhibit squamous follicular cells and larger intercellular spaces when compared to those observed in the previous stage. The oocyte cytoplasm present granular and viscous yolk, the latter is the result of the breakdown of granules. Stage V oocytes exhibit a follicular epithelium almost completely degenerated, smaller quantities of granular yolk and large amounts of viscous yolk. Based on our findings we established the sequence of yolk deposition in M. fimbriolata oocyte as follows: proteins and lipids, which are first produced by endogenous processes in stages I and II oocytes. Exogenous incorporation begins in stage III. In stages I and II oocytes, lipids are also produced by follicular epithelial cells. The third element to be deposited is polysaccharides, mainly found as complexes. Therefore, the yolk present in the oocytes of this species consists of glycolipoproteins. Molecular weights of proteins present in M. fimbriolata oocytes ranged from 10 to 92 KDa, differently from vitellogenin, the most common protein present in insect oocytes, weighing approximately 180 KDa.     

Ferritin in iron containing granules from the fat body of the honeybees Apis mellifera and Scaptotrigona postica

It is already known that the behaviour of the honeybee Apis mellifera is influenced by the Earth's magnetic field. Recently it has been proposed that iron-rich granules found inside the fat body cells of this honeybee had small magnetite crystals that were responsible for this behaviour. In the present work, we studied the iron containing granules from queens of two species of honeybees (A. mellifera and Scaptotrigona postica) by electron microscopy methods in order to clarify this point. The granules were found inside rough endoplasmic reticulum cisternae. Energy dispersive X-ray analysis of granules from A. mellifera showed the presence of iron, phosphorus and calcium. The same analysis performed on the granules of S. postica also indicated the presence of these elements along with the additional element magnesium. The granules of A. mellifera were composed of apoferritin-like particles in the periphery while in the core, clusters of organised particles resembling holoferritin were seen. The larger and more mineralised granules of S. postica presented structures resembling ferritin cores in the periphery, and smaller electron dense particles inside the bulk. Electron spectroscopic images of the granules from A. mellifera showed that iron, oxygen and phosphorus were co-localised in the ferritin-like deposits. These results indicate that the iron-rich granules of these honeybees are formed by accumulation of ferritin and its degraded forms together with elements present inside the rough endoplasmic reticulum, such as phosphorus, calcium and magnesium. It is suggested that the high level of phosphate in the milieu would prevent the crystallisation of iron oxides in these structures, making very unlikely their participation in magnetoreception mechanisms. They are most probably involved in iron homeostasis.     

The venom gland of queens of Apis mellifera (Hymenoptera, Apidae): morphology and secretory cycle

The venom gland of queens of Apis mellifera was examined through light and transmission electron microscopy and subjected to electrophoretic analyses. Virgin queens exhibited prismatic secretory cells containing large amounts of rough endoplasmic reticulum with dilated cisternae, open secretory spaces, numerous vacuoles and granules scattered in the cytoplasm, and spherical nuclei with numerous nucleoli. The secretion produced was non-refringent under polarized light and the electrophoretic analysis of glandular extracts revealed five main protein bands. In mated queens, the venom gland exhibited a high degree of degeneration. Its secretion was refringent under polarized light and one of the main bands was absent in the electrophoretic pattern obtained. The morphological aspects observed are in agreement with the function of this gland in queens, given that virgin queens use venom in battles for the dominance of the colony, a situation that occurs as soon as they emerge, while fertilized queens rarely use venom.     

Differential tissue expression of a calpastatin isoform in Xenopus embryos

This study is aimed at demonstrating the role played by a calpastatin isoform (Xcalp3) in Xenopus embryos. A specific monoclonal antibody (mAb) was raised against a glutathione S-transferase (GST)-Xcalp3 fusion protein and characterized by immunoblotting and confocal fluorescence microscopy on stage 20-36 embryos. Under these conditions, calpastatin reactivity is associated with a major 110kDa protein fraction and preferentially expressed by notochord and somitic cells. In notochord cells, anti-calpastatin reactive sites were initially restricted to the luminal space of the vacuoles and later became diffused throughout the cytoplasm. In contrast, anti-calpastatin reactive sites in somitic cells were initially diffused throughout the cytoplasm and became restricted to a few intracellular granules in the later developmental stages. At the ultrastructural level, notochord cells appeared as flattened discs containing several vacuoles and numerous electron-dense granules. During transition from stages 26 to 32, electron-dense granules were gradually reduced in number as vacuoles enlarged in size and losed their calpastatin reactivity. Electron-dense granules were also present in myoblast cells and their number gradually reduced during development. To determine whether these observations bear any causal relationship to the calpain/calpastatin system, a number of Xenopus embryos were examined both ultrastructurally and histochemically following exposure to a specific calpain inhibitor (CI3). Under these conditions, Xenopus embryos exhibited an altered right-left symmetry and an abnormal axial shortening. In CI3-treated stage 32 embryos, notochord cells had a reduced vacuolar extension and exhibited at the same time an increase in granular content. The overall morphology of the somites was also distorted and myoblasts were altered both in shape and granular content. Based on these findings, it is concluded that the calpain/calpastatin may play an important role in the control of notochord elongation and somite differentiation during Xenopus embryogenesis.     

Changes in the haemocytes of Agrotis ipsilon larvae (Lepidoptera: Noctuidae) in relation to dimilin and Bacillus thuringiensis infections

Five types of haemocytes are observed in the fourth larval instar of the black cutworm, Agrotis ipsilon: prohaemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs), spherule cells (SPs) and adipohaemocytes (ADs). Infection of A. ipsilon fourth larval instar with Bacillus thuringiensis and dimilin resulted in a reduction of the total haemocyte count. Changes in the differential haemocyte population during bacterial and dimilin infections have been assessed. The PRs % decreased significantly while SPs, PLs, and GRs % increased significantly after the application of the two insecticides at 12 and 24 h. Ultrastructural alternations and malformations have been observed in circulating haemocytes of A. ipsilon larvae treated with dimilin and B. thuringiensis.     

Ultrastructural study of the ovary of the sugarcane spittlebug Mahanarva fimbriolata (Hemiptera)

The present study describes the ultrastructure of meroistic telotrophic ovaries of the sugarcane spittlebug Mahanarva fimbriolata. In this type of ovary, nurse cells, oogonia, and prefollicular tissue are located at the terminal (distal) regions or tropharium of ovarioles. Oocytes in different developmental stages, classified from I to V, are observed in the vitellarium. Stage I oocytes do not exhibit intercellular spaces in the follicular epithelium, suggesting that synthesis and production of yolk during this stage occurs only through endogenous processes. Small yolk granules of different electron densities are present in the cytoplasm. Few lipid droplets are observed. Stage II oocytes exhibit small intercellular spaces in the follicular epithelium. More protein as well as lipid yolk granules are observed in the cytoplasm. In stage III oocytes, intercellular spaces in the follicular epithelium are larger than those observed in the previous stage. Electrondense protein granules of various sizes, larger than those observed in stage II oocytes predominate in the cytoplasm. Smaller lipid droplets are also present. In stage IV oocytes, the follicular epithelium exhibits large intercellular spaces. Our data clearly indicate that the opening of these spaces in the follicular epithelium of M. fimbriolata oocytes increases as the intake of exogenous proteins intensifies, that is, in stages IV and V oocytes. During these stages, granular yolk becomes viscous due to the lysis of granules. In stage V oocytes, viscous yolk predominates in the cytoplasm. This type of yolk, however, has not been described for other orders of insects. The chorion of M. fimbriolata oocytes consists of an external layer (exochorion) and an internal one (endochorion), which is in direct contact with the oocyte. Numerous small pores that probably facilitate oxygenation of the internal structures inside the eggs are observed in the exochorion.     

Cytopathology of the trachea of Bombyx mori (Lepidoptera: Bombycidae) to Bombyx mori nucleopolyhedrovirus

Bombyx mori is a holometabolous insect found only in germplasm banks and morphological data related of resistance and susceptibility to diseases is important when selecting hybrids for commercial and scientific interest. This study analyzed the cytopathology of B. mori trachea to BmNPV, isolated geographically in Paraná state, Brazil. Fifth instar larvae were divided into two groups, control and inoculated; the viral suspension used was 2.4 × 10⁷ polyhedral occlusion bodies/mL. From the second to the ninth day post-inoculation, segments of silkworm organs, containing the trachea, were processed for transmission electron microscopy. Analyses of fresh hemolymph were also performed to verify the susceptibility of the hemocytes. Signs of infection were initially detected in the hemocytes and in the tracheal cells on the second and fourth post-inoculation days, respectively. The cytopathology of the trachea showed all stages of the viral cycle, which was the same as in other tissues. Virions were detected in the basal lamina, which showed structural disorganization. So, the infection time of the hemocytes prior to trachea and the presence of virus in basal lamina, suggests that the trachea was a secondary target, infected by budded virus coming from the hemolymph.     

Ultrastructure of the female reproductive apparatus of the egg parasitoid Gryon pennsylvanicum (Ashmead) (Hymenoptera,Platygastridae)

The growing interest in Leptoglossus occidentalis, the conifer seed bug pest accidentally introduced into Europe in the 1990s, led us to investigate the female reproductive structures of the hymenopteran platygastrid Gryon pennsylvanicum, which is its candidate antagonist for biological control programmes. Our study revealed a genital apparatus with some characteristic features, such as an unusual length of the oviduct (divided into a long proximal and a short distal tract), the absence of accessory glands and the presence of a spermatheca provided with a small spermathecal gland. The ultrastructural investigation revealed that the shorter part of the common oviduct is involved in ion uptake whereas the longer part has two cell types with secretory function: the former with dense bodies and the latter with granular particles. The secretory contents of both are released into the oviduct lumen. The granular particles are formed in a complex of modified endoplasmic reticulum and appear as virus-like particles.     

The evidence of Tobacco rattle virus impact on host plant organelles ultrastructure

Tobraviruses, like other (+) stranded RNA viruses of plants, replicate their genome in cytoplasm and use such usual membranous structures like endoplasmic reticulum. Based on the ultrastructural examination of Tobacco rattle virus (TRV)-infected potato and tobacco leaf tissues, in this work we provide evidence of the participation of not only the membranous and vesicular ER structures but also other cell organelles during the viral infection cycle. Non-capsidated TRV PSG particles (potato isolate from the Netherlands) (long and short forms) were observed inside the nucleus while the presence of TRV capsid protein (CP) was detected in the nucleus caryolymph and within the nucleolus area. Both capsidated and non-capsidated viral particles were localized inside the strongly disorganized chloroplasts and mitochondria. The electron-dense TRV particles were connected with vesicular structures of mitochondria as well as with chloroplasts in both potato and tobacco tissues. At 15–30 days after infection, vesicles filled with TRV short particles were visible in mitochondria revealing the expanded cristae structures. Immunodetection analysis revealed the TRV PSG CP epitope inside chloroplast with disorganized thylakoids structure as well as in mitochondria of different tobacco and potato tissues. The ultrastructural analysis demonstrated high dynamics of the main cell organelles during the TRV PSG–Solanaceous plants interactions. Moreover, our results suggest a relationship between organelle changes and different stages of virus infection cycle and/or particle formation.     

The Study of Radiation Damage Mechanism on Ultra-Structures of Leukocytes and Platelets in Rat Cells

The principal objective of this study was to assess the mechanisms relevant to radiation-induced damage to multicore leukocytes and platelets, using a Transmission Electron Microscope (TEM). In this study, in the group subjected to 5 Gy irradiation, platelet size was reduced by 25%, and the cell membranes were thick and not clearly visible. On the 20-day and 30-day observations, passed leukocytes and mitochondrial damage were shown to be increased. The mass of glycogen granules was also reduced. In the 7 Gy irradiation group, platelet size was even more profoundly reduced. In the erythrocytes, most echinocytes, which generally exhibit burrs, were irregularly shaped, and sickle cells were observed. In the observation of leukocytes, no evidence of radiation damage was detected in the primary or secondary granules. Damage to the nuclear membrane and cell membrane was increased. The outline of the centrosome was somewhat dim. In the 7 Gy irradiation group, no damage was detected in specific granules of the basophil. Phagocytosis of amoebal movement was observed. In some parts of the lymphocyte, nuclei were divided or formed a space between the nucleus and cytoplasm and were sensitive to radiation.     

Diffusion inside living human cells

Naturally occurring lipid granules diffuse in the cytoplasm and can be used as tracers to map out the viscoelastic landscape inside living cells. Using optical trapping and single particle tracking we found that lipid granules exhibit anomalous diffusion inside human umbilical vein endothelial cells. For these cells the exact diffusional pattern of a particular granule depends on the physiological state of the cell and on the localization of the granule within the cytoplasm. Granules located close to the actin rich periphery of the cell move less than those located towards to the center of the cell or within the nucleus. Also, granules in cells which are stressed by intense laser illumination or which have attached to a surface for a long period of time move in a more restricted fashion than those within healthy cells. For granules diffusing in healthy cells, in regions away from the cell periphery, occurrences of weak ergodicity breaking are observed, similar to the recent observations inside living fission yeast cells [1].