Trans-differentiation of iris pigmented epithelial cells of Euphlyctis cyanophlyctis tadpoles into lens in vitro.

Meshed pigmented iris epithelium along with neural retina of tadpoles of the frog Euphlyctis cyanophlyctis were found to undergo dedifferentiation and subsequently transdifferentiate into lens in culture medium. During lag period, depigmentation (dedifferentiation) occurred in many cells. When culture became confluent 3-4 weeks after seeding tiny lens like structures differentiated from foci of cultured pigmented iris epithelium cells. The percentage of lens formation was higher in vitamin A treated cases. The culture system appears to be a suitable for investigating the changes occurred during trans-differentiation of pigmented epithelial cells into lens.

Morphological regional differences of epithelial cells along the midgut in Diatraea saccharalis Fabricius (Lepidoptera: Crambidae) larvae / Diferenças morfológicas regionais das células epiteliais ao longo do intestino médio de larvas de Diatraea saccharalis Fabricius (Lepidoptera: Crambidae)

The sugarcane borer, Diatraea saccharalis Fabricius, is a pest to sugarcane and many other crops. This work aims to characterize morphological variability in the epithelial cells (columnar, goblet and regenerative) along the midgut of D. saccharalis larvae. Fragments of the midgut (anterior, middle and posterior regions) were fixed and processed by light and scanning electron microscopy. There are both cytochemical and ultrastructural differences in the morphology of the epithelial cells, depending on their localization along the midgut. The apical surface of columnar cells shows an increase in both number and size of the apical protrusions from the anterior to the posterior midgut regions. There is an increase in the amount of PAS-positive (Periodic Acid-Schiff Reaction) granules detected in the cytoplasm of both the columnar and regenerative cells, from the anterior to the posterior region. The goblet cell apical surface is narrow in the anterior region, and enlarged in the posterior midgut; the chamber's cytoplasm extrusion are small and thin at the apical cavity surface, being thicker, longer and more numerous at the basal portion of the cavity. Our results suggest that the sugarcane borer midgut has two morphologically different regions, the anterior and the posterior; the middle region is a transitional region.

A broca da cana, Diatraea saccharalis Fabricius, é uma praga da cana-de-açúcar e outras plantações. O objetivo deste trabalho foi caracterizar variações morfológicas nas células epiteliais (colunares, caliciformes e regenerativas) ao longo do intestino médio de larvas de D. saccharalis. Fragmentos do intestino médio (anterior, mediano e posterior) foram fixados e processados para microscopia de luz e eletrônica de varredura. Existem diferenças morfológicas citoquímicas e ultra-estruturais nas células epiteliais, dependendo da sua localização no intestino médio. A superfície apical de algumas células colunares exibe projeções citoplasmáticas que aumentam em número e volume da região anterior para a posterior do intestino médio. Existe aumento dos grânulos PAS-positivos (Reação de Schiff) no citoplasma apical das células colunares e regenerativas, da região anterior para a posterior. A câmara das células caliciformes, na região anterior do intestino médio, mostra seu ápice estreito, enquanto que na posterior essa porção da câmara é alargada; as evaginações citoplasmáticas da câmara são pequenas e finas no ápice, sendo numerosas, longas e mais espessas na porção basal. Os resultados sugerem que o intestino médio da broca da cana apresenta duas regiões morfologicamente distintas, a anterior e posterior; a região mediana é uma região de transição.

Huevo, larva en primer estadio y aparato genital femenino de la mariposa Chabuata castanea (Lepidoptera: Noctuidae)

Egg, first larval stage and female genitalia of the moth Chabuata castanea (Lepidoptera: Noctuidae). Egg, first larval stage, and female genitalia of the widely distributed moth Chabuata castanea are described, based on material from Talcahuano, VIII region, Chile. Egg microestructures are illustrated with scannig electron microscope images which show that egg morphology allows identification to species level. Rev. Biol. Trop. 55 (2): 659-664. Epub 2007 June, 29.

Se describe el huevo, larva de primer estadio y aparato genital de la hembra de Chabuata castanea con material proveniente de Talcahuano, VIII región, Chile y de huevos obtenidos en laboratorio. Se fotografiaron los huevos con microscopia electrónica de barrido para analizar las variaciones entre micropila, celdas primarias y secundarias, concluyéndose que las diferencias permiten una identificación al nivel de especie.

New Helicoverpa armigera Hbn cell line from larval hemocyte for baculovirus studies.

A new cell line from the larval hemocytes of H. armigera was established in Grace's medium modified by adding lactalbumin hydrolysate and yeastolate (3.3g/l), and supplemented with fetal bovine serum (20%). The cell line was designated as NIV-HA-1195. The cell population at P-78 consisted mainly of epithelial-like cells (89.36%), fibroblast-like cells (8.31%) and giant cells (2.13%). The population doubling time was 96hr at P-8, 60hr at P-43. The chromosome number ranged from 45 to 200. The cell line is susceptible to the baculoviruses, Autographa californica nucleopolyhedrovirus (AcNPV), Spodoptera litura NPV and the homologous HaNPV. Isoenzyme profile and results of 16S rRNA heteroduplex analysis clearly indicated the species specificity of the new cell line.

Changes in haemolymph constituents of American bollworm, Helicoverpa armigera (Hübner), infected with nucleopolyhedrovirus.

Six types of haemocytes viz., prohaemocytes, plasmatocytes (round, fusiform, vermiform and spindle shaped), granular cells, spherule cells, oenocytoids and adipohaemocytes were found in the haemolymph of larvae of American bollworm H. armigera. The total and differential haemocyte counts (THC and DHC) in H. armigera haemolymph were affected by nucleopolyhedrovirus (NPV) treatment. There was a general decrease in THC in response to NPV treatment in both young and old larvae. However the decrease was more apparent in 5 and 8 day old larvae than in 10 day old larvae. The differential haemocytes showed less of granular cells and more of spherule cells and prohaemocytes in the old larvae. Plasmatocytes and granular cells in 10 day old larvae initially phagocytosed polyhedra; however, disintegrated after 3 to 4 hr. The haemolymph of NPV treated larvae melanized slowly particularly in old larvae. Phenoloxidase (PO) activity decreased positively with granular cells and oenocytoids in 10 day old treated larvae. Cellular fraction had high level of PO activity, which was transferred to plasma in response to NPV infection in the older larvae. The role of NPV pathogenesis vis-à-vis immunity in insect is discussed.

A new continuous cell line from larval hemocytes of Spodoptera litura (F.).

A new cell line has been established from larval hemocytes of the moth, S. litura (tobacco cut worm). It took 147 days to form a monolayer and one year for the first 17 passages. At present, the culture is at 86th passage level and is designated NIV-SU-1095. Three cell types could be distinguished, viz. plasmatocytes (53%), prohemocytes (36%) and granular hemocytes (11%). The chromosome number was very high, 74% metaphase cells showed more than 100 chromosomes. The cells could be cryopreserved. The cells were susceptible to the baculoviruses, Autographa californica nuclear polyhedrosis virus and S. litura nuclear polyhedrosis virus (SLNPV). Plaques could be observed on 7th post infection day with SLNPV. Six cloned cell lines have been developed of which clone II-1F was more sensitive to both the baculoviruses compared to the original cell line.

The polytene chromosomes of Cnsia dissimilis (Edwards) and three species of Gigantodax Enderlein (Diptera: Simuliidae) from Lanin National Park (Argentina)

Cytological studies were made on larvae of Giagantodax marginalis. G. chilensis, G. fulvescens and Cnesia dissimilis from four creeks in Lanin National Park, Neuquen Province, Argentina. Chromosome maps and idiograms of these species are presented. The following inversions were observed: G. marginalis: IL-1 (X-linked inversion), IL-2 (Y-linked inversion), IIS-1.2, IIL-1, IIIL-4,5; G. chilinsis: IL-4 (X-linked inversions), IIS-1.2, IIIL-4,5; G. fulvescens: IL-1 (X-linked inversion), IL-3 (Y-linked inversion), IIS-1.2, IIL-1, IIIL-4,5; C. dissimilis: IL-1, IL-5, IIIL-1. Karyological information was used to construct a cladogram and Cnesia sp. Was found to show close resemblance to the three Gigantodax spp.

Possible formation of new brood capsule by the previously formed brood capsule in Echinococcus multilocularis metacestodes.

In Echinococcus multilocularis metacestodes obtained from the peritoneal cavity of an experimentally infected jird, cellular accumulations were found not only on the inner surfaces of germinal layers but also on the outer surfaces of brood capsules. These cellular accumulations are believed to represent at incipient form of the brood capsule. It has been thought that brood capsules are produced by the germinal layer, but we speculate that the brood capsule itself, as well as the germinal layer, may have the potential to produce new brood capsules.

Assessment of some preservation and staining methods of encysted larvae of helminths

In hydatid cysts, the best results were obtained with specimens fixed in 10% formalin and stained with Zeihl-Neelsen. Trichinella cysts a high degree of perfection was obtained with specimen fixed in 10% formalin and stained with haematoxylin and eosin, or fixed in glycerol 4% saline and stained with .the former stain or with Delafield's stain. Equal degree of perfection was mostly obtained with the forementioned stains when fixed in Bouin's or Zenker's fixative