Functional zonation of the adrenal cortex is a consequence of the zone-specific expression of P450c17 (CYP17A1) and its cofactors. Activin and inhibin peptides are differentially produced within the zones of the adrenal cortex and have been implicated in steroidogenic control. In this study, we investigated whether activin and inhibin can function as intermediates in functional zonation of the ...

Landslides are a major geologic hazard with estimated tens of deaths and $1–2 billion in economic losses per year in the US alone. The island of Puerto Rico experiences one or two large events per year, often triggered in steeply sloped areas by prolonged and heavy rainfall. Identifying areas susceptible to landslides thus has great potential value for Puerto Rico and would allow better managem...

Although the zonation of the adrenal cortex has a clear functional role, the mechanisms that maintain it remain largely conjectural. The concept that an outer proliferative layer gives rise to cells that migrate inwards, adopting sequentially the zona glomerulosa, fasciculata and reticularis phenotypes, has yet to be explained mechanistically. In other tissues, Eph receptor (EphR)/ephrin signal...

A previously described digitonin-perfusion technique [Quistorff, Grunnet & Cornell (1985) Biochem. J. 226, 289-297], by which intracellular material of rat liver could be liberated, has been refined, now allowing release of cytosol of high purity from both periportal and perivenous parts of the same liver. The cytosolic fractions are obtained by perfusing the liver for short intervals (10-20 s)...

Mangroves are prone to bearing frequently the full brunt of hurricanes and tropical storms. The extent of destruction and early regeneration are widely studied. The purpose of this study was to add a long-term view of mangrove regeneration and assess the potential effects on mangrove horizontal zonation patterns of catastrophic destruction. Hattie, a category five hurricane, hit the Belizean co...

Hepatic glucose metabolism is zonated. Glycolysis is mainly localized in hepatocytes surrounding the hepatic vein (pericentral zone) whereas gluconeogenesis is mainly carried out by hepatocytes surrounding the portal vein (periportal zone). Expression of the gene encoding the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK, PCK1) is reduced upon feeding. PEPCK is considered a peri...

1 We investigated the factors producing zonation patterns of the dominant plants in south-eastern USA salt marshes where Juncus roemerianus dominates the high marsh, and Spartina alterniflora the middle and low marsh. 2 Juncus did not occur naturally in the Spartina zone and performed poorly when transplanted there, irrespective of whether neighbours were present or removed, indicating that its...

This project utilizes microfluidic systems to study how groups of liver cells acquire emergent tissue properties. Hepatocytes (the parenchymal cells of the liver) respond to many cues in their microenvironment: neighboring cells, growth factors, extracellular matrix, dissolved oxygen, and their interactions. One tissue property of interest is the compartmentalization of gene expression in multi...

Abstract: Aim Zooplankton functional groups play an important role in lake functioning and can readily respond to environmental changes may be associated with phytoplankton changes. In warmer regions, zooplankton species have a smaller body size, which decreases their grazing capacity, attenuating top-down control throughout phytoplankton. We evaluated density biomass of relationship algal hori...