Divergence estimates and early evolutionary history of Figitidae (Hymenoptera: Cynipoidea)

We examine the phylogenetic relationships of Figitidae and discuss host use within this group in light of our own and previously published divergence time data. Our results suggest Figitidae, as currently defined, is not monophyletic. Furthermore, Mikeiinae and Pycnostigminae are sister‐groups, nested adjacent to Thrasorinae, Plectocynipinae and Euceroptrinae. The recovery of Pycnostigminae as sister‐group to Mikeiinae suggests two major patterns of evolution: (i) early Figitidae lineages demonstrate a Gondawanan origin (Plectocynipinae: Neotropical; Mikeiinae and Thrasorinae: Australia; Pycnostigminae: Africa); and (ii) based on host records for Mikeiinae, Thrasorinae and Plectocynipinae, Pycnostigminae are predicted to be parasitic on gall‐inducing Hymenoptera. The phylogenetic position of Parnips (Parnipinae) was unstable, and various analyses were conducted to determine the impact of this uncertainty on both the recovery of other clades and inferred divergence times; when Parnips was excluded from the total evidence analysis, Cynipidae was found to be sister‐group to [Euceroptrinae + (Plectocynipinae (Thrasorinae + (Mikeiinae + Pycnostigminae)))], with low support. Divergence dating analyses using BEAST indicate the stem‐group node of Figitidae to be c. 126 Ma; the dipteran parasitoids (Eucoilinae and Figitinae), were estimated to have a median age of 80 and 88 Ma, respectively; the neuropteran parasitoids (Anacharitinae), were estimated to have a median age of 97 Ma; sternorrhynchan hyperparasitoids (Charipinae), were estimated to have a median age of 110 Ma; the Hymenoptera‐parasitic subfamilies (Euceroptinae, Plectocynipinae, Trasorinae, Mikeiinae, Pycnostigminae, and Parnipinae), ranged in median ages from 48 to 108 Ma. Rapid radiation of Eucoilinae subclades appears chronologically synchronized with the origin of their hosts, Schizophora (Diptera). Overall, the exclusion of Parnips from the BEAST analysis did not result in significant changes to divergence estimates. Finally, though sparsely represented in the analysis, our data suggest Cynipidae have a median age of 54 Ma, which is somewhat older than the age of Quercus spp (30–50 Ma), their most common host.     

Teloplasm formation in a leech, Helobdella triserialis, is a microtubule-dependent process

Fertilized eggs of the leech Helobdella triserialis undergo a cytoplasmic reorganization which generates domains of nonyolky cytoplasm, called teloplasm, at the animal and vegetal poles. The segregation of teloplasm to one cell of the eight-cell embryo is responsible for a unique developmental fate of that cell, i.e., to give rise to segmental ectoderm and mesoderm. We have studied the cytoplasmic movements that generate teloplasm using time-lapse video microscopy; the formation and migration of rings of nonyolky cytoplasm were visualized using transmitted light, while the movements of mitochondria into these rings were monitored with epifluorescence after labeling embryos with rhodamine 123, a fluorescent mitochondrial dye. To examine the likelihood that cytoskeletal elements play a role in the mechanism of teloplasm formation in Helobdella, we examined the distribution of microtubules and microfilaments during the first cell cycle by indirect immunofluorescence and rhodamine-phalloidin labeling, respectively. The cortex of the early embryo contained a network of microtubules many of which were oriented parallel to the cell surface. As teloplasm formation ensued, microtubule networks became concentrated in the animal and the vegetal cortex relative to the equatorial cortex. More extensive microtubule arrays were found within the rings of teloplasm. Actin filaments appeared in the form of narrow rings in the cortex, but these varied apparently randomly from embryo to embryo in terms of number, size, and position. The role of microtubules and microfilaments in teloplasm formation was tested using depolymerizing agents. Teloplasm formation was blocked by microtubule inhibitors, but not by microfilament inhibitors. These results differ significantly from those obtained in embryos of the oligochaete Tubifex hattai, suggesting that the presumably homologous cytoplasmic reorganizations seen in these two annelids have different cytoskeletal dependencies.     

2007 Annual progress report synopsis of the Center for Structures of Membrane Proteins

A synopsis of the 2007 annual progress report for the Center for Structures of Membrane Proteins, a specialized center of the Protein Structure Initiative.     

Therapeutic implications of GIPC1 silencing in cancer

GIPC1 is a cytoplasmic scaffold protein that interacts with numerous receptor signaling complexes, and emerging evidence suggests that it plays a role in tumorigenesis. GIPC1 is highly expressed in a number of human malignancies, including breast, ovarian, gastric, and pancreatic cancers. Suppression of GIPC1 in human pancreatic cancer cells inhibits in vivo tumor growth in immunodeficient mice. To better understand GIPC1 function, we suppressed its expression in human breast and colorectal cancer cell lines and human mammary epithelial cells (HMECs) and assayed both gene expression and cellular phenotype. Suppression of GIPC1 promotes apoptosis in MCF-7, MDA-MD231, SKBR-3, SW480, and SW620 cells and impairs anchorage-independent colony formation of HMECs. These observations indicate GIPC1 plays an essential role in oncogenic transformation, and its expression is necessary for the survival of human breast and colorectal cancer cells. Additionally, a GIPC1 knock-down gene signature was used to interrogate publically available breast and ovarian cancer microarray datasets. This GIPC1 signature statistically correlates with a number of breast and ovarian cancer phenotypes and clinical outcomes, including patient survival. Taken together, these data indicate that GIPC1 inhibition may represent a new target for therapeutic development for the treatment of human cancers.     

RETRACTED: SENSORY SUGGESTIVENESS AND LABELING: DO SOY LABELS BIAS TASTE?1

Can labels suggestively influence sensory perceptions and taste? Using a “ Phantom Ingredient” taste test, we show that the presence or absence of a labeled ingredient (soy) and the presence or absence of a health claim negatively bias taste perceptions toward a food erroneously thought to contain soy. We found a label highlighting soy content made health claims believable but negatively influenced perceptions of taste for certain segments of consumers. Our results and discussion provide better direction for researchers who work with ingredient labeling as well as for those who work with soybean products.