ADELINA FERREIRA^1,* AND MAHMOUD MEHANNA²

BIOCELL, Vol.36, No.2, pp. 57-62, 2012, DOI:10.32604/biocell.2012.36.057

Abstract The reproductive cycle in anurans may be either continuous or discontinuous. These differences may be connected to seasonal climate changes and/or to anthropic activity. Forty adult male individuals of the Dendropsophus minutus species were collected during one year, in the municipality of Chapada dos Guimarães (Mato Grosso, Brazil). The testicles were studied under light and transmission electron microscopy. No variations were observed when the diameter of the seminiferous tubules and the thickness of the interstitial tissue were studied. However, changes in spermatogenesis were conspicuous and indicated that the reproductive cycle of D. minutus in Chapada dos Guimarães More >

ISRAEL A. VEGA^*1,2, FEDERICO A. DELLAGNOLA¹, JORGE A. HURST³, MARTÍN S. GODOY¹ AND ALFREDO CASTRO-VAZQUEZ^1,2

BIOCELL, Vol.36, No.2, pp. 47-55, 2012, DOI:10.32604/biocell.2012.36.047

Abstract Pigments present in the brown-greenish C morph of an intracellular endosymbiont of Pomacea canaliculata were investigated. Acetone extracts of the endosymbiotic corpuscles showed an absorption spectrum similar to that of chlorophylls. Three fractions obtained from silica gel column chromatography of the acetone extracts (C_I , C_II and C_III ), were studied by positive ion fast atom bombardment-mass spectrometry (FAB–MS) and hydrogen-nuclear magnetic resonance (H-NMR). Results indicated the presence of (1) a sterol in the yellow colored C_I fraction; (2) a mixture of pheophorbides a and b in the major green fraction, C_II; and (3) a modified pheophorbide a in the More >

RANA IMANI¹, SHAHRIAR HOJJATI EMAMI¹, HOSSEIN FAKHRZADEH², NAFISEH BAHEIRAEI¹, ALI M SHARIFI^{* 2,3,4}

BIOCELL, Vol.36, No.1, pp. 37-45, 2012, DOI:10.32604/biocell.2012.36.037

Abstract The ultimate goal of tissue engineering is to design and fabricate functional human tissues that are similar to natural cells and are capable of regeneration. Preparation of cell aggregates is one of the important steps in 3D tissue engineering technology, particularly in organ printing. Two simple methods, hanging drop (HD) and conical tube (CT) were utilized to prepare cell aggregates. The size and viability of the aggregates obtained at different initial cell densities and pre-culture duration were compared. The proliferative ability of the cell aggregates and their ability to spread in culture plates were also… More >

MAURO RODRIGO SURENCISKI^*, EDUARDO ALBERTO FLACHSLAND, GRACIELA TERADA, LUIS AMADO MROGINSKI, HEBE YOLANDA REY

BIOCELL, Vol.36, No.1, pp. 31-36, 2012, DOI:10.32604/biocell.2012.36.031

Abstract The aim of the present study was to investigate the efficiency of the encapsulation-dehydration technique for cryopreservation of Cyrtopodium hastchbachii Pabst seeds. Immature seeds of this species were cryopreserved by an encapsulation-dehydration technique. Seeds of five immature pods, 120 days after pollination, were encapsulated in 3% calcium alginate matrix and pretreated in liquid medium supplemented with 0.08 M sucrose (24 h), 0.15 M sucrose (24 h), 0.25 M sucrose (48 h), 0.5 M sucrose (24 h) and 0.75 M sucrose (24 h) in shaker at 60 rpm. Alginate beads were dehydrated 5 h in silicagel and More >

ORLANDO J. CASTEJÓN^*

BIOCELL, Vol.36, No.1, pp. 1-29, 2012, DOI:10.32604/biocell.2012.36.001

Abstract The Purkinje cell and their synaptic contacts have been described using (1) light microsocopy, (2) transmission and scanning electron microscopy, and freeze etching technique, (3) conventional and field emission scanning electron microscopy and cryofracture methods, (4) confocal laser scanning microscopy using intravital stain FM64, and (5) immunocytochemical techniques for Synapsin-I, PSD9-5, GluR1 subunit of AMPA receptors, N-cadherin, and CamKII alpha. The outer surface and inner content of plasma membrane, cell organelles, cytoskeleton, nucleus, dendritic and axonal processes have been exposed and analyzed in a three-dimensional view. The intramembrane morphology, in bi- and three-dimensional views, and More >

Gil SP, L Seisdedos, ME Reyna, MM Cerana

Phyton-International Journal of Experimental Botany, Vol.81, pp. 205-210, 2012, DOI:10.32604/phyton.2012.81.205

Abstract The goals of this study were (1) to make a careful study of the foliar epidermis of Grindelia cabrerae var. cabrerae, Solidago chilensis y Wedelia buphthalmiflora, native Asteraceae from Argentina which have ornamental potential, and (2) to determine variables that indicate adaptation to xeromorphic environments. Five adult leaves from five plants were selected from each population. All the material was fixed in FAA. The epidermis of both foliar sides were macerated in hypochlorite of sodium, and obtained by scraping. They were stained with safranine and mounted in water-glycerine (1:1). From each slide, five fields were chosen and… More >

Galussi AA^1,2, ME Moya^1,2, LR Zimmermann¹, FG Marchese^1,2, YG Gillij^1,2, F Torres^1,2

Phyton-International Journal of Experimental Botany, Vol.81, pp. 255-260, 2012, DOI:10.32604/phyton.2012.81.255

Abstract Mnesithea selloana (known as cola de largarto, teyú ruguay) is a spring-summer-fall species that flowers and fructifies in that period; it has good forage quality, and it is in danger of extinction in the natural grasslands at the study region. The objectives of this work were to study the sinflorescence morphology, and the maturity and quality of the caryopsis to know its reproductive aspects in relation to the dissemination of this especies in grazing areas. The sinflorescence was studied in two plants during a period of 45 days, between October and December 2010, within an experimental… More >

Luján-Rangel R¹, E Olivares-Sáenz², RE Vázquez-Alvarado², L Garza-Ocañas¹, O Torres-Alanís^1(†), HJ Garza-Ulloa¹

Phyton-International Journal of Experimental Botany, Vol.81, pp. 247-253, 2012, DOI:10.32604/phyton.2012.81.247

Abstract Karwinskia parvifolia Rose synthesizes a toxin (PA1), which might be used to treat some types of tumors. Variability from 16 plants of K. parvifolia and the effect of nitrogen was evaluated on its dry fruit yield. The experiment was carried out using a crossover design, two treatment sequences and two production cycles. Collected data were: dry fruit yield (DFY), dry fruit weight (DFW) and dry endocarp weight (DWE) per plant. During Cycle 1, the group of plants that received additional nitrogen (CN) produced higher yields than the group that received no additional nitrogen (SN). Ratios of CN/SN More >

Iglesias LG¹, LY Solís-Ramos², H Viveros-Viveros³

Phyton-International Journal of Experimental Botany, Vol.81, pp. 239-246, 2012, DOI:10.32604/phyton.2012.81.239

Abstract The morphometric variation of cones, seeds and needles was evaluated in two natural populations of Pinus hartwegii at Veracruz state to estimate the percentage of phenotypic variation due to differences among populations and trees within populations. In addition, multivariate principal components, cluster and discriminate analysis was conducted to characterize the populations. Most of the traits measured on cones, seeds and needles showed significant variation both among populations and among trees within populations. Measurements of cone and seed traits used as indicators of the genetic and reproductive status of two natural populations of P. hartwegii revealed that much… More >

Peter G^1,2, FA Funk³, A Loydi⁴, AI Casalini⁵, CV Leder⁴

Phyton-International Journal of Experimental Botany, Vol.81, pp. 233-237, 2012, DOI:10.32604/phyton.2012.81.233

Abstract In the western Monte Phytogeographical Province of Rio Negro, vegetation is a shrubby-grassland steppe, where plants are interspersed within a bare soil matrix forming “phytogenic islands”. The objective of this study was to evaluate the specific composition and cover of the study ecological system under different grazing pressures. We selected areas with high, moderate and low grazing intensity at three sites. In each area we established five linear transects, where basal cover and all intercepted species were registered. Sites were arranged through a Principal Component Analysis using the Infostat software. We analyzed similarity between sites, More >