Nodule ultrastructure and initial growth of Anadenanthera peregrina (L.) Speg. var. falcata (Benth.) Altschul plants infected with rhizobia

The anatomy and ultrastructure of root nodules of Anadenanthera peregrina var. falcata (Leguminosae-Mimosoideae) were analysed, as was plant growth. To ensure that nodules developed, seedlings were inoculated with a mixture of six strains of rhizobia. Nodules were produced that differed in appearance-and probably also effectiveness-but their structure was similar and they showed characteristics typical of indeterminate nodules, such as persistent meristematic tissue and a gradient of cells at different stages of development. Many starch grains were present in inner cortex cells and interstitial cells of infected tissue. Infected cells were densely packed with bacteroids, which contained many poly-beta-hydroxybutyrate granules. The high incidence of these granules, together with high levels of starch accumulation in interstitial cells, suggested low N-2-fixation efficiency of the rhizobia isolates used for inoculation. In the symbiosomes of early-senescent infected cells, reticulum-like structures, small vesicles and a fibrillar material were observed; these may be related to bacteroid degradation. In the cytoplasm of late-senescent infected cells, many vesicles and membrane-like structures were observed, probably associated with membrane degradation of bacteroids and peribacteroids. The total biomass of plants inoculated with rhizobia was low and their xylopodia and shoots had low levels of N compared with non-inoculated plants fertilized with ammonium nitrate. However, inoculated plants did not show N-deficiency symptoms and grew better than non-inoculated plants without N fertilization. These growth results, together with ultrastructural observations of nodules, suggest that nitrogen fixation of rhizobia isolates associated with Anadenanthera peregrina var. falcata roots is poor. (C) 2002 Annals of Botany Company.

Structure, histochemistry, and ultrastructure of the epithelium and stroma in the gerbil (Meriones unguiculatus) female prostate

The female prostate has aroused scientific interest because it is subjected to the same diseases compromising the male prostate during aging. The objective of this work was to characterize structurally, cytochemically, and ultrastructurally the tissue compartments of the normal adult female prostate of Meriones unguiculatus gerbils. The morphological analyses showed that the gerbil's female prostate is constituted of a cluster of glands and ducts inserted in a musculofibrous stroma. The alveolar epithelium is differentiated and consisted of basal proliferating cells, intermediary cells, and secretory cells. The secretory cells are the most numerous cell type and continuously secrete glycoproteins. The basal cells are the source of the secretory cells and they are then responsible for the alveolus renovation. The prostatic stroma is abundant and rich in elastic and collagen fibers, which are closely associated with smooth muscle cells and fibroblasts. The results showed that the gerbil's female prostate shows morphological and ultrastructural homology to the human female prostate (Skene's gland), and despite being a small organ, it is a mature and physiologically active gland. (C) 2003 Elsevier Ltd. All rights reserved.

Liver Anatomy, Histochemistry, and Ultrastructure of Eupemphix nattereri (Anura: Leiuperidae) During the Breeding Season

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Implications of obesity for tendon structure, ultrastructure and biochemistry: A study on Zucker rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultrastructural characteristics of spermatogenesis in Pallas's mastiff bat, Molossus molossus (Chiroptera: Molossidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Espermiogênese em Eupemphix nattereri (Anura, Leiuperidae): aspectos ultra-estruturais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seminal analysis, cryogenic preservation, and fertility in matrinxã fish, Brycon cephalus (Günther, 1869)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Colleters in Caryocar brasiliense (Caryocaraceae) ontogenesis, ultrastructure and secretion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Organization of the cysts in bee (Hymenoptera, Apidae) testis: number of spermatozoa per cyst

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anatomy, ultrastructure and secretion of Hibiscus pernambucensis Arruda (Malvaceae) extrafloral nectary

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultrastructure of ovarian follicular epithelium of the Amazonian fish Pseudotylosurus microps (Teleostei: Belonidae): morphological and histochemical characterization of the intercellular deposits

Neste trabalho é mostrada a grande quantidade de material eletrondenso intercelular no epitélio folicular de P. microps. Aparentemente, o material é captado da circulação e enviado para o folículo por meio dos espaços intercelulares, acumulando-se nos espaços intercelulares médio-apicais do epitélio e no espaço perioocítico. A acumulação é iniciada no oócito primário e prossegue até a vitelogênese. A natureza química desse material é discutida.

CYTOPLASMIC AND PLASMA-MEMBRANE ULTRASTRUCTURE OF PARACOCCIDIOIDES-BRASILIENSIS YEAST-PHASE CELLS AS REVEALED BY FREEZE-ETCHING

Using a freeze-etch technique the cytoplasmic and plasma membrane ultrastructure of Paracoccidiodies brasiliensis yeast-phase cells was studied. The multinucleate yeast-phase cells which grow by simultaneous multiple budding, like those of Mucor sp. contain several nuclei, mitochondria, well-developed ER, small vacuoles and lipid droplets. Complex structures with no apparent connexion to the plasma membrane of P. brasiliensis usually lack inveginations, but invaginations which do occur are always rod-shaped which indicates P. brasiliensis to be of either ascomycetous or basidiomycetous origin.

Functional ultrastructure of the midgut of the fire ant Solenopsis saevissima Forel 1904 (Formicidae : Myrmicinae)

Solenopsis saevissima has a midgut composed of columnar, regenerative, and goblet cells. The midgut epithelium was covered by a basal lamina. Outside the basal lamina, layers of inner oblique, circular, and outer longitudinal muscles were present. Columnar cells showed a basal plasma membrane containing numerous folds, mitochondria, and the nucleus. Rough endoplasmic reticulum, Golgi bodies, membrane bounded vacuoles, and spherocrystals were found in this region. The apical plasma membrane was constituted by microvilli, which were above a region rich in mitochondria. Regenerative cells were found in groups lying by the basal lamina. Goblet cells were associated with an ion-transporting mechanism between the haemolymph and the midgut epithelium. These cells were lying by the midgut lumen and large microvilli were evident, but the cytoplasmic features were similar to the columnar cells.