Mice with Disrupted TGFβ Signaling Have Normal Cerebella Development,but Exhibit Facial Dysmorphogenesis and Strain-Dependent Deficits in Their Body Wall

The transforming growth factor betas (TGFβs) are context-dependent regulators of neurons in vitro, but their physiological functions in the brain are unclear. Haploinsufficiency of either Tgfβ1 or Tgfβ2 leads to age-related deterioration of neurons, but the development of the brain is normal in the full absence of either of these genes. However, some individuals with mis-sense mutations of TGFβ receptors are mentally retarded, suggesting that the TGFβ isoforms can compensate for each other during brain development. This possibility was tested by generating mice (NSE × PTR) with neuron-specific expression of a dominant-negative inhibitor of TGFβ signaling. The NSE × PTR mice with a FVBxC57Bl/6 genetic background were viable and developed normally despite strong neuronal expression of the inhibitor of TGFβ signaling. Their cerebella were of normal size and contained normal numbers of neurons. When the genetic background of the mice was changed to C57BL/6, the phenotype of the mice became neonatal lethal, with the neonates exhibiting various malformations. The malformations correlated with sites of non-neuronal expression of the transgenes and included facial dysmorphogenesis, incomplete closure of the ventral body wall and absence of intestinal motility. The C57BL/6 Tgfbm1–3 alleles, which modulate the phenotype of Tgfβ1^−/− mice, were not major determinants of the NSE × PTR phenotype. The data suggest that the development of the cerebellum is insensitive to the level of TGFβ signaling, although this may be dependent on the genetic background.     

Estimating product and energy substitution benefits in national‐scale mitigation analyses for Canada

The potential of forests and the forest sector to mitigate greenhouse gas (GHG) emissions is widely recognized, but challenging to quantify at a national scale. Mitigation benefits through the use of forest products are affected by product life cycles, which determine the duration of carbon storage in wood products and substitution benefits where emissions are avoided using wood products instead of other emissions‐intensive building products and energy fuels. Here we determined displacement factors for wood substitution in the built environment and bioenergy at the national level in Canada. For solid wood products, we compiled a basket of end‐use products and determined the reduction in emissions for two functionally equivalent products: a more wood‐intensive product vs. a less wood‐intensive one. Avoided emissions for end‐use products basket were weighted by Canadian consumption statistics to reflect national wood uses, and avoided emissions were further partitioned into displacement factors for sawnwood and panels. We also examined two bioenergy feedstock scenarios (constant supply and constrained supply) to estimate displacement factors for bioenergy using an optimized selection of bioenergy facilities which maximized avoided emissions from fossil fuels. Results demonstrated that the average displacement factors were found to be similar: product displacement factors were 0.54 tC displaced per tC of used for sawnwood and 0.45 tC tC^?1 for panels; energy displacement factors for the two feedstock scenarios were 0.47 tC tC^?1 for the constant supply and 0.89 tC tC^?1 for the constrained supply. However, there was a wide range of substitution impacts. The greatest avoided emissions occurred when wood was substituted for steel and concrete in buildings, and when bioenergy from heat facilities and/or combined heat and power facilities was substituted for energy from high‐emissions fossil fuels. We conclude that (1) national‐level substitution benefits need to be considered within a systems perspective on climate change mitigation to avoid the development of policies that deliver no net benefits to the atmosphere, (2) the use of long‐lived wood products in buildings to displace steel and concrete reduces GHG emissions, (3) the greatest bioenergy substitution benefits are achieved using a mix of facility types and capacities to displace emissions‐intensive fossil fuels.     

Lafutidine versus Lansoprazole in Combination with Clarithromycin and Amoxicillin for One versus Two Weeks for Helicobacter pylori Eradication in Korea

Background and Aims: Lafutidine is a novel H₂‐receptor antagonist with gastroprotective activity that includes enhancement of gastric mucosal blood flow. The aim of the present study was to test the efficacy of 7‐ or 14‐day lafutidine–clarithromycin–amoxicillin therapy versus a lansoprazole‐based regimen for Helicobacter pylori eradication. Methods: Four hundred and sixty‐three patients with H. pylori‐infected peptic ulcer disease were randomized to one of four regimens: (1) lafutidine (20 mg b.i.d.), clarithromycin (500 mg b.i.d.) and amoxicillin (1000 mg b.i.d.) for 7 days (the 7LFT group) or (2) for 14 days (the 14LFT group); (3) lansoprazole (30 mg b.i.d.), clarithromycin (500 mg b.i.d.), and amoxicillin (1000 mg b.i.d.) for 7 days (the 7LPZ group); or (4) for 14 days (the 14LPZ group). The eradication rates, drug compliance, and adverse effects among the four regimens were compared. Results: The eradication rates by the intention‐to‐treat and per‐protocol analyses in the 7LFT and 7LPZ groups were 76.5% and 81.6%, and 76.9% and 82.0% (p = .94 and .95), respectively. The eradication rates by intention‐to‐treat and per‐protocol analyses in the 14LFT and 14LPZ groups were 78.2% and 82.2%, and 80.4% and 85.9% (p = .70 and .49), respectively. The treatment duration for 7 days or 14 days did not affect the eradication rates. In addition, the adverse effect rates and discontinuation rates were similar among the four groups. Furthermore, the ulcer cure rate and symptom response rate were similar in the lafutidine and lansoprazole groups. Conclusion: The results of this study showed that lafutidine–clarithromycin–amoxicillin therapy was a safe and effective as lansoprazole‐based triple therapy for the eradication rate of H. pylori, and could be considered as an additional treatment option.     

Forest Fragmentation Reduces Seed Dispersal of Duckeodendron cestroides, a Central Amazon Endemic

Fragmentation that alters mutualistic relationships between plants and frugivorous animals may reduce the seed dispersal of trees. We examined the effects of forest fragmentation on the distributions of seeds and seedlings of a Central Amazon endemic tree, Duckeodendron cestroides . In the dry seasons of 2002–2004, seeds and first-year seedlings were counted within wedge-shaped transects centered around Duckeodendron adults in fragments and nearby continuous forests at the Biological Dynamics of Forest Fragmentation Project. Analyses showed that fragmentation reduced seed dispersal quantity and quality. The percent and distance of dispersed seeds were both twice as great in continuous forest as in fragments. The distances of each tree's five furthest dispersed seeds were three times greater in continuous forest than fragments. Over the 3-yr study, 20 times more seeds were dispersed more than 10 m from parent crowns in continuous forest than fragments. A regression analysis showed more dispersed seeds at all distances in continuous forest than fragments. Dispersal differences were strong in 2002 and 2004, years of large fruit crops, but weak or absent in 2003, when fruit production was low. As distance from parent crowns increased, the number of seedlings declined more rapidly in fragments than continuous forest. Distance-dependent mortality between the seed and seedling stages appeared to be more important in continuous forest than fragments. This research provides ample, indirect evidence demonstrating that forest fragmentation can result in the breakdown of a seed dispersal mutualism, potentially jeopardizing the reproduction of a rare, tropical tree.     

Distinguishing between convergence and parallelism is central to comparative biology: a reply to Williams and Ebach

The definitions of character similarity, homology, homoplasy, heterology, parallelism and convergence are clarified in the framework of current phylogenetic methodology. They are all associated with definite patterns of character change and can consequently be tested by phylogeny building. Their crucial significance in comparative biology is illustrated using demonstrative examples. © The Willi Hennig Society 2006.     

GAS6 is an estrogen-inducible gene in mammary epithelial cells

To identify estrogen-responsive genes in mammary glands, microarray assays were performed. Twenty genes were found to be up-regulated while 16 genes were repressed in the 9h estrogen treated glands. The induction of GAS6, one of the genes up-regulated by estrogen, was confirmed by RNase protection assay. Furthermore, GAS6 was also demonstrated to be induced by estrogen in ER positive breast cancer cells. Analysis of GAS6 promoter revealed that GAS6 promoter was regulated by estrogen. An estrogen response element (ERE) was identified in the GAS6 promoter. Electrophoretic mobility shift assay revealed that ERalpha interacted with the ERE in the GAS6 promoter. Chromatin immunoprecipitation demonstrated that ERalpha was recruited to the GAS6 promoter upon estrogen stimulation. These results suggested that GAS6 is an estrogen target gene in mammary epithelial cells.     

Abdominal-B is essential for proper sexually dimorphic development of the Drosophila gonad

Sexual dimorphism requires the integration of positional information in the embryo with the sex determination pathway. Homeotic genes are a major source of positional information responsible for patterning along the anterior-posterior axis in embryonic development, and are likely to play a critical role in sexual dimorphism. Here, we investigate the role of homeotic genes in the sexually dimorphic development of the gonad in Drosophila. We have found that Abdominal-B (ABD-B) is expressed in a sexually dimorphic manner in the embryonic gonad. Furthermore, Abd-B is necessary and sufficient for specification of a sexually dimorphic cell type, the male-specific somatic gonadal precursors (msSGPs). In Abd-B mutants, the msSGPs are not specified and male gonads now resemble female gonads with respect to these cells. Ectopic expression of Abd-B is sufficient to induce formation of extra msSGPs in additional segments of the embryo. Abd-B works together with abdominal-A to pattern the non-sexually dimorphic somatic gonad in both sexes, while Abd-B alone specifies the msSGPs. Our results indicate that Abd-B acts at multiple levels to regulate gonad development and that Abd-B class homeotic genes are conserved factors in establishing gonad sexual dimorphism in diverse species.     

Expression of the BnmNAP subfamily of napin genes coincides with the induction of Brassica microspore embryogenesis

Brassica napus cv. Topas microspores can be diverted from pollen development toward haploid embryo formation in culture by subjecting them to a heat stress treatment. We show that this switch in developmental pathways is accompanied by the induction of high levels of napin seed storage protein gene expression. Changes in the plant growth or microspore culture conditions were not by themselves sufficient to induce napin gene expression. Specific members of the napin multigene family were cloned from a cDNA library prepared from microspores that had been induced to undergo embryogenesis. The majority of napin clones represented three members (BnmNAP2, BnmNAP3 and BnmNAP4) that, along with a previously isolated napin genomic clone (BngNAP1), constitute the highly conserved BnmNAP subfamily of napin genes. Both RNA gel blot analysis, using a subfamily-specific probe, and histochemical analysis of transgenic plants expressing a BngNAP1 promoter--glucuronidase gene fusion demonstrated that the BnmNAP subfamily is expressed in embryogenic microspores as well as during subsequent stages of microsporic embryo development.