Defaunation of large-bodied frugivores reduces carbon storage in a tropical forest of Southeast Asia.

Recent studies have suggested that defaunation of large-bodied frugivores reduces above-ground carbon storage in tropical forests of South America and Africa, but not, or less so, in Southeast Asian tropical forests. Here we analyze the issue using the seed dispersal network (data of interaction between trees and animal seed dispersers) and forest composition of a 30-ha forest dynamics plot in central Thailand, where an intact fauna of primates, ungulates, bears and birds of all sizes still exists. We simulate the effect of two defaunation scenarios on forest biomass: 1) only primates extirpated (a realistic possibility in near future), and 2) extirpation of all large-bodied frugivores (LBF) including gibbons, macaques, hornbills and terrestrial mammals, the main targets of poachers in this region.

Different megafauna vary in their seed dispersal effectiveness of the megafaunal fruit Platymitra macrocarpa (Annonaceae).

The world's largest terrestrial animals (megafauna) can play profound roles in seed dispersal. Yet, the term 'megafauna' is often used to encompass a diverse range of body sizes and physiologies of, primarily, herbivorous animals. To determine the extent to which these animals varied in their seed dispersal effectiveness (SDE), we compared the contribution of different megafauna for the large-fruited Platymitra macrocarpa (Annonaceae), in a tropical evergreen forest in Thailand.

A nuclear protein is required for thyroid hormone receptor binding to an inhibitory half-site in the epidermal growth factor receptor promoter.

The epidermal growth factor (EGF) receptor (EGFR) promoter is negatively regulated by thyroid hormone and retinoic acid. This regulation can be mapped to a 36-basepair GC-rich region of the promoter (EGFR P/E) that functions autonomously as a promoter and an enhancer when placed in front of the thymidine kinase gene TATA element. Direct high affinity binding of the thyroid hormone receptor (T3R) to this element requires a nuclear protein.

Ligand-activated thyroid hormone and retinoic acid receptors inhibit growth factor receptor promoter expression.

Thyroid hormone (T3) and retinoic acid (RA) receptors mediate ligand-dependent inhibition of epidermal growth factor (EGF) receptor and c-erbB2/neu promoter activities. Ligand-activated T3 and RA receptors act via a 36 bp 5' fragment of the EGF receptor gene in vivo and, in the presence of nuclear extract, bind with high affinity to this region in vitro. Both ligand binding and DNA binding domains of T3 and RA receptors are required for promoter inhibition.

Regulation of epidermal growth factor receptor gene expression.

Synthesis and metabolism of the epidermal growth factor (EGF) receptor are extensively regulated to modulate cellular responses to ligand. To study regulation of EGF receptor gene expression, the 5' region of the gene was isolated from a human placental genomic library. A 5' proximal 1.