KARINA M. MICHETTI^1,2, PATRICIA I. LEONARDI^1,3, EDUARDO J. CÁCERES^1,4

BIOCELL, Vol.30, No.3, pp. 491-496, 2006, DOI:10.32604/biocell.2006.30.491

Abstract Nonspecific acid phosphatases are a group of enzymes whose activity increases the availability of exogenous and endogenous orthophosphate either through extra- or intracellular hydrolysis of phosphate compounds. Our study demonstrates the activity of acid phosphatases in the filamentous freshwater alga Stigeoclonium tenue. These enzymes were detected following a cerium-based method in which cerium was used as an orthophosphate-capture reagent. In thalli from S. tenue from the natural environment, acid phosphatases were found in the longitudinal cell wall, plasmalemma, and vacuole. In thalli from Bold’s Basal Medium culture, these enzymes were found mainly in the plasmalemma; they were scarce in the… More >

ROSANA N. MALPASSI

BIOCELL, Vol.30, No.1, pp. 51-56, 2006, DOI:10.32604/biocell.2006.30.051

Abstract Eleusine indica and Portulaca oleracea are two common weeds in peanut crops in southern Córdoba. Two chemicals are frequently used to control them, quizalofop for grasses and lactofen for dicots. The objective is to study the effects of quizalofop and lactofen on cuticle ultrastructure in E. indica and P. oleracea, respectively. In the lab, quizalofop was applied on E. indica and lactofen on P. oleracea. Three plant categories were analyzed in each species: 3, 1-2, and no tiller in E. indica, and 8, 6, and 2 nomophylls in P. oleracea. Leaf samples from both species were collected at 7 and… More >

MARIA CAROLINA AQUINO LUQUE, SÔNIA NAIR BÁO

BIOCELL, Vol.30, No.1, pp. 33-38, 2006, DOI:10.32604/biocell.2006.30.033

Abstract The ultrastructure of normal, ejaculated spermatozoa of Bos indicus was studied by means of electron microscopy, being evaluated in two principal parts, the head and the tail. The head is flat, oval or paddle-shaped with a square base, which provides a concave recess for the insertion of the tail. The acrosome tightly covers the anterior two thirds of the nucleus. A distinct unilateral acrosomal bulge was observed along the apical edge of the head. The equatorial region demarcates the acrosome from the post-equatorial region that covers the caudal one third of the nucleus. The classical 9+9+2 fiber pattern which composes… More >

SONIA ROSENFELDT, BEATRIZ G. GALATI

BIOCELL, Vol.29, No.3, pp. 271-278, 2005, DOI:10.32604/biocell.2005.29.271

Abstract The correlation between the ontogeny of Ubisch bodies and pollen development in Oxalis articulata was studied with Transmission Electron Microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells are related to Ubisch bodies, sporopollenin and pollen-kitt formation. The pro-orbicules have the appearance of lipid globuli and their formation is related to the endoplasmic reticulum of rough type (ERr). The lipid globules or pro-orbicules disappear in the mature Ubisch bodies, and the places that they occupied remain free of contents or with pollen-kitt. More >

LILIANA G. SOUSA¹, ELENA I. CUARTAS², ANA MARÍA PETRIELLA^{1, 3}

BIOCELL, Vol.29, No.1, pp. 25-31, 2005, DOI:10.32604/biocell.2005.29.025

Abstract The aim of this study is to describe the ultrastructure of the hepatopancreas of P. argentinus in intermoult. P. argentinus hepatopancreas was studied using standard TEM techniques. Each tubule consists of four cellular types: E (embryonic), F (fibrillar), R (resorptive) and B (blister like). E-cells have embryonic features and some of them were found in mitosis. F, R and B cells possess an apical brush border. F-cells have a central or basal nucleus, a conspicuous RER, and dilated Golgi cisternae. R cells show a polar organization of organelles in three areas: apical, with numerous mitochondria and sER tubules, a central… More >

KARINA MANCINI, HEIDI DOLDER

BIOCELL, Vol.28, No.3, pp. 299-310, 2004, DOI:10.32604/biocell.2004.28.299

Abstract This study was undertaken to detect protein components in both sperm types of the butterfly Euptoieta hegesia. These spermatozoa possess complex extracellular structures for which the composition and functional significance are still unclear. In the apyrene sperm head, the proteic cap presented an external ring and an internal dense content; basic proteins were detected only in external portions. In the tail, the paracrystalline core of mitochondrial derivatives and the axoneme are rich in proteins. The extratesticular spermatozoa are covered by a proteic coat, which presented two distinct layers. In eupyrene spermatozoa, acrosome and nucleus were negatively stained, probably because of… More >

ELIANE VICTORIANO, ELISA A. GREGÓRIO

BIOCELL, Vol.28, No.2, pp. 165-169, 2004, DOI:10.32604/biocell.2004.28.165

Abstract The Lyonet’s gland is found in Lepidoptera larvae, close to the excretory duct of the silk gland. The role played by this gland is still uncertain. This work aims to describe the ultrastructure of the Lyonet’s gland in Diatraea saccharalis larvae, offering suggestions regarding its possible function. The insects were reared under laboratory-controlled conditions. The glands were conventionally prepared for transmission (TEM) and scanning (SEM) electron microscopy. SEM showed that Lyonet’s glands are paired small structures located in the ventral side of the head. They are composed by clustered long cells resembling leaves. Under TEM observations, each cell is surrounded… More >

ADELINA FERREIRA, HEIDI DOLDER

BIOCELL, Vol.27, No.3, pp. 353-362, 2003, DOI:10.32604/biocell.2003.27.353

Abstract Spermatogenesis, with emphasis on spermiogenesis, is described for the lizard, Tropidurus itambere, using light microscopy, phase contrast and epifluorescence, as well as scanning and transmission electron microscopy. Cellular differentiation involves events of chromatin condensation, nuclear elongation and the formation of structural complexes, such as the acrosomal and axonemal ones. Other new characteristics, exclusive for this species, include various aspects of the subacrosomal granule, the insertion of the proacrosomal vesicle and the development of these structures to participate in the acrosomal complex. Radial projections occur just above the nuclear shoulders, which have been recognized already from the beginning of cellular elongation.… More >

Montes B^1,2, MG Murray^1,3

Phyton-International Journal of Experimental Botany, Vol.84, No.1, pp. 201-208, 2015, DOI:10.32604/phyton.2015.84.201

Abstract Palynological studies contribute to understanding the taxonomy, phylogeny and ecology of the Asteraceae and other families. In this study, pollen morphology and ultrastructure of the exine of Senecio bergii Hieron. were studied using light, scanning and transmission electron microscopy. The pollen of this species is prolate-spheroidal, it has a Senecioid pattern on the exine and an apertural system composed of three apertures (ecto-, meso- and endoapertures). This pollen type is defined as tricolpororate due to the triple apertural system. This is the first description of the ultrastructure of the apertural system of the pollen of Argentine species of Senecio. The… More >