Somaclonal variation: a morphogenetic and biochemical analysis of Mandevilla velutina cultured cells

Cell cultures of Mandevilla velutina have proved to be an interesting production system for biomass and secondary metabolites able to inhibit the hypotensive activity of bradykinin, a nonapeptide generated in plasma during tissue trauma. The crude ethyl acetate extract of cultured cells contains about 31- to 79-fold more potent anti-bradykinin compounds (e.g., velutinol A) than that obtained with equivalent extracts of tubers. Somaclonal variation may be an explanation for the wide range of inhibitor activity found in the cell cultures. The heterogeneity concerning morphology, differentiation, carbon dissimilation, and velutinol A production in M. velutina cell cultures is reported. Cell cultures showed an asynchronous growth and cells in distinct developmental stages. Meristematic cells were found as the major type, with several morphological variations. Cell aggregates consisting only of meristematic cells, differentiated cells containing specialized cell structures such as functional chloroplasts (cytodifferentiation) and cells with embryogenetic characteristics were observed. The time course for sucrose metabolism indicated cell populations with significant differences in growth and metabolic rates, with the highest biomass-producing cell line showing a cell cycle 60 percent shorter and a metabolic rate 33.6 percent higher than the control (F2 cell population). MALDI-TOF mass spectrometric analysis of velutinol A in selected cell lines demonstrated the existence of velutinol A producing and nonproducing somaclones. These results point to a high genetic heterogeneity in general and also in terms of secondary metabolite content

Use of lectins to evaluate the effects of GaAS softlaser on dog tendon

1. Lectins labeled with colloidal gold particles were used for the ultrastructural evaluation of the biological effects of GaAs softlaserirradiation on the healing of dog tendon wounds. 2. Six dogs were submitted to tenotomy and tenorrhaphy on the right and left hind legs. All animals received laser irradiation (4J/cm²) daily for ten days only on the left leg, and the right leg of the same animal was used as control. Biopsies were taken 11, 22 and 40 days after surgery. 3. Laser-irradiated and control tendon tissues were embedded in L.R. White resin and thin section were incubated in the presence of gold-labeled Arachis hypogaea (PNA), Canavalia ensiformes (Con A) and Triticum vulgare (WGA). 4. In general, the control and laser-irradiated tissues presented homogeneous and similar labelling of heterochromatin, rough endoplasmic reticulum and extracellular matrix. 5. We conclude that GaAs softlaser irradiation does not produce significant changes in the glycosylation of healing tendons