Influence of test tube sealing on the morpho-anatomy and ultrastructure of leaves of Aechmea bromeliifolia (Bromeliaceae) grown in vitro

Abstract In vitro grown plants may have abnormal structural and physiological features. However, the type of the sealing material used in tissue culture may minimize such abnormalities. This study evaluates the influence of the type of sealing of test tubes on the anatomical and ultrastructural features of leaves of Aechemea bromeliifolia (Rudge) Baker (Bromeliaceae), an ornamental bromeliad native to Brazil, grown in vitro. Three types of sealing were used: rigid polypropylene cap (PC), polyvinyl chloride film (PVC), and PC coupled with a microporous membrane (PM). Seedlings germinated in a greenhouse were also studied for comparison. Plants grown in test tubes sealed with PM were more similar to those from the greenhouse, as far as the pattern of stomatal opening, the presence of starch grains, and the organization of the internal membrane system of the chloroplasts is concerned. Plants cultivated in test tubes sealed with PC had higher stomatal density and the chloroplasts had large areas without thylakoids in the stroma. Plants grown in test tubes sealed with PVC had few or no starch grains. These results suggest that microporous membrane used coupled with PC sealing provided natural ventilation, thus contributing to a better plant development.

Budding process during the organogenesis of the ventral prostatic lobe in Mongolian gerbil

The prostate is a mammalian gland that shows a complex process of organogenesis. Here, a morphological study to characterize the organogenesis of the ventral prostate lobe in male gerbils was conducted. The urogenital sinus (UGS) was dissected out and processed for paraffin embedding. Histological sections were subjected to cytochemical, immunofluorescence, immunohistochemical, and three-dimensional reconstruction techniques. We found that the first ventral buds emerged from the ventral urethral epithelium between the days 20 and 21 of prenatal life, reaching the ventral mesenchymal pad and initiating the branching process on the first day of postnatal life. The buds presented a V-shaped elongation, suggesting that the smooth muscle layer (SML) plays an important role during budding events. Indeed, whereas the androgen receptor (AR) was preferentially found in the UGS mesenchyme (UGM), estrogen receptor alpha (ERα) was localized in both the UGM and in the emerging buds. This study characterized the morphological aspects of the budding process in a different rodent from rat and mice, serving as a new model for future studies on developmental biology of the prostate.