Long-term growth in vitro of isolated, fully differentiated neurones from the central nervous system of an adult insect

A method is described for the isolation and growth in vitro of fully differentiated neurones from the thoracic ganglia of adult cockroaches. The presence of insect blood in the culture system is shown to promote growth. The morphology of the growing neurones and the plasticity of the branching processes are described and growth rates are measured. Using a fluorescent Ca2+ indicator dye, changes of intracellular calcium levels in the growing neurones in response to K+ depolarization have been measured. The results, indicating the presence of voltage-dependent Ca2+ channels on neuronal processes in vitro, show that neurones can be maintained in a functional state for several weeks by this technique. Such preparations could prove useful for studying a variety of physiological and pharmacological properties of neurones, including the mechanisms controlling growth, synapse formation and neuronal interactions with other cell types. <br/

Plasma Sex Steroid Levels and Steroidogenesis in the Gonad of the Self-fertilizing Fish Rivulus marmoratus

The mangrove killifish, Rivulus marmoratus, is the only known self-fertilizing vertebrate. This species is sexually dimorphic; sexually mature individuals are either hermaphrodite or primary and secondary males. Although the mangrove killifish has a unique reproductive strategy, there has been no study on the reproductive endocrinology of this species. Thus we investigated plasma sex steroid hormone levels and steroidogenesis in the gonads of R. marmoratus by enzyme linked immunosorbent assay (ELISA). Plasma 17β-estradiol (E2) and 11-ketotestosterone (11-KT) were detected both in hermaphrodite and in primary male. Ovarian follicles (follicle-enclosed oocytes) from hermaphrodites, which were categorized into early yolk stage and late yolk stage, and testis tissue of primary males were cultured with different concentrations of 17α-hydroxyprogesterone (OHP) or testosterone (T) for 24 h. Production of T, E2, 11-KT and 17α-20 β-dihydroxy-4-pregnen-3-one (17α,20β-P) in the medium from tissue culture were measured by ELISA. Early and late ovarian follicles of hermaphrodites and testis pieces of primary males synchronously secreted E2, 11-KT, and 17α,20β-P following incubation with OHP or T. We conclude that both hermaphrodite and primary male of the mangrove killifish secrete estrogen, androgen, and progestin synchronously

State of the world’s plants and fungi 2020

Kew’s State of the World’s Plants and Fungi project provides assessments of our current knowledge of the diversity of plants and fungi on Earth, the global threats that they face, and the policies to safeguard them. Produced in conjunction with an international scientific symposium, Kew’s State of the World’s Plants and Fungi sets an important international standard from which we can annually track trends in the global status of plant and fungal diversity

Phenotypic Modulation of Human Urinary Tract Stroma-derived Fibroblasts by Transforming Growth Factor β3

OBJECTIVES Animal models have described critical roles for transforming growth factor beta (TGF beta) isoforms in modulating urinary tract stroma phenotype. TGF beta 3 is of particular interest because it may regulate TGF beta 1 and TGF beta 2 expression, but its modulatory affect has not been so well characterized in human cells. In this study, we aim to determine whether TGF beta 3 treatment induced differentiation of human urinary tract stroma-derived fibroblasts to a smooth muscle-like phenotype. METHODS We established cultures of human urinary tract stroma-derived fibroblasts and studied the effects of TGF beta 3 treatment using proliferation assays, cell cycle analysis, immunocytochemistry, and Western blotting for expression of differentiation marker and downstream regulators, and fura-2 fluorescence to study the effects on intracellular calcium. RESULTS TGF beta 3 treatment induced proliferation that peaked at 72 hours, followed by enhanced expression of alpha-smooth muscle actin (alpha-SMA) with a maximal 3.4-fold increase at 168 hours. TGF beta 3 treatment decreased resting [Ca2+](i) by 70% and caused a 95% decrease in stimulated internal Ca2+ release regulated by the sarcoplasmic/endoplasmic calcium-ATPase pump. These effects were associated with upregulation of nuclear activator of T cells -1 (NFAT), a known regulator of cell differentiation. CONCLUSIONS TGF beta 3 treatment causes a time-specific response in the presence of serum, whereby fibroblasts initially proliferate and subsequently differentiate to a smooth muscle-like phenotype. This sequence was associated with stabilization of [Ca2+](i) stores, suggesting a role in the induction of hyperplasia and reduction of contractility; phenomena associated with a number of urinary tract pathologies