Canonical Wnt signaling is required for ophthalmic trigeminal placode cell fate determination and maintenance

Cranial placodes are ectodermal regions that contribute extensively to the vertebrate peripheral sensory nervous system. The development of the ophthalmic trigeminal (opV) placode, which gives rise only to sensory neurons of the ophthalmic lobe of the trigeminal ganglion, is a useful model of sensory neuron development. While key differentiation processes have been characterized at the tissue and cellular levels, the signaling pathways governing opV placode development have not. Here we tested in chick whether the canonical Wnt signaling pathway regulates opV placode development. By introducing a Wnt reporter into embryonic chick head ectoderm, we show that the canonical pathway is active in Pax3+ opV placode cells as, or shortly after, they are induced to express Pax3. Blocking the canonical Wnt pathway resulted in the failure of targeted cells to adopt or maintain an opV fate, as assayed by the expression of various markers including Pax3, FGFR4, Eya2, and the neuronal differentiation markers Islet1, neurofilament, and NeuN, although, surprisingly, it led to upregulation of Neurogenin2, both in the opV placode and elsewhere in the ectoderm. Activating the canonical Wnt signaling pathway, however, was not sufficient to induce Pax3, the earliest specific marker of the opV placode. We conclude that canonical Wnt signaling is necessary for normal opV placode development, and propose that other molecular cues are required in addition to Wnt signaling to promote cells toward an opV placode fate.     

The number of loci that affect milk production traits in dairy cattle

We have used the results of an experiment mapping quantitative trait loci (QTL) affecting milk yield and composition to estimate the total number of QTL affecting these traits. We did this by estimating the number of segregating QTL within a half-sib daughter design using logic similar to that used to estimate the "false discovery rate" (FDR). In a half-sib daughter design with six sire families we estimate that the average sire was heterozygous for approximately 5 QTL per trait. Also, in most cases only one sire was heterozygous for any one QTL; therefore at least 30 QTL were likely to be segregating for these milk production traits in this Holstein population.     

Proposed minimum reporting standards for chemical analysis

There is a general consensus that supports the need for standardized reporting of metadata or information describing large-scale metabolomics and other functional genomics data sets. Reporting of standard metadata provides a biological and empirical context for the data, facilitates experimental replication, and enables the re-interrogation and comparison of data by others. Accordingly, the Metabolomics Standards Initiative is building a general consensus concerning the minimum reporting standards for metabolomics experiments of which the Chemical Analysis Working Group (CAWG) is a member of this community effort. This article proposes the minimum reporting standards related to the chemical analysis aspects of metabolomics experiments including: sample preparation, experimental analysis, quality control, metabolite identification, and data pre-processing. These minimum standards currently focus mostly upon mass spectrometry and nuclear magnetic resonance spectroscopy due to the popularity of these techniques in metabolomics. However, additional input concerning other techniques is welcomed and can be provided via the CAWG on-line discussion forum at or . Further, community input related to this document can also be provided via this electronic forum. The contents of this paper do not necessarily reflect any position of the Government or the opinion of the Food and Drug Administration Sponsor: Metabolomics Society http://www.metabolomicssociety.org/ Reference: http://msi-workgroups.sourceforge.net/bio-metadata/reporting/pbc/ http://msi-workgroups.sourceforge.net/chemical-analysis/ Version: Revision: 5.1 Date: 09 January, 2007     

Does Anthropomorphism of Dogs Affect Pain Perception in Animal-Assisted Interventions? An Exploratory Study

The purpose of this exploratory study was to determine the effects of anthropomorphism of a therapy dog on pain perception during an animal-assisted intervention. Participants were 32 college women who were randomly assigned to the anthropomorphism condition or the control condition. All participants engaged in a pretest cold pressor task to measure base-line individual differences in pain tolerance and perceptions of pain intensity and pain unpleasantness. After completing this task, participants in the anthropomorphism group engaged in a task intended to prime them to view a therapy dog anthropomorphically. Specifically, they rated photos of dogs on a series of humanlike traits (e.g., “this dog would be a good listener”). Participants in the control condition rated photos of dogs on a series of canine traits (e.g., “this dog would make a good watchdog”). After this experimental manipulation, participants engaged in a second cold pressor task in the presence of a therapy dog and the therapy dog handler. We hypothesized that participants in the anthropomorphism group would demonstrate greater pain tolerance and report lower levels of pain intensity and pain unpleasantness during the second cold pressor task than participants in the control group. Results provide partial support for these hypotheses. Participants in the anthropomorphism group reported lower posttest pain intensity than participants in the control group. In addition, they demonstrated greater posttest pain tolerance than participants in the control group—but only under conditions of medium or high pretest pain tolerance. The two groups did not differ with respect to posttest pain unpleasantness. The results of this exploratory study provide preliminary evidence that prompting individuals to view a therapy dog anthropomorphically may augment their experience of pain relief from a therapy dog visit.