A mouse cerberus/Dan-related gene family

The Xenopus cerberus gene is able to induce ectopic heads in Xenopus embryos. At the time of its identification, cerberus shared significant homology with only one other protein, the putative rat tumor suppressor protein Dan. Sequence analysis has revealed that cerberus and Dan are members of a family of predicted secreted proteins, here called the can family. The identification of a can-family member in the nematode Caenorhabditis elegans, CeCan1, suggests that this family is of ancient origin. In the mouse, there are at least five family members: Cer1, Drm, PRDC, Dan, and Dte. These genes are expressed in patterns that suggest that they may play important roles in patterning the developing embryo. Cer1 marks the anterior visceral endoderm at E6.5. Dte is expressed asymmetrically in the developing node. Dan is first seen in the head mesoderm of early head fold stage embryos and Drm is expressed in the lateral paraxial mesoderm at E8.5. The region of homology shared by these genes, here called the can domain, closely resembles the cysteine knot motif found in a number of signaling molecules, such as members of the TGFbeta superfamily. Epitope-tagged versions of Cer1 show that, unlike in TGFbeta superfamily members, the cysteine knot motif is not processed away from a proprotein. Recent experiments in Xenopus have suggested that cerberus may act as an inhibitor of BMP signaling. To examine this further, the ability of Dan, Cer1, and human DRM to attenuate Bmp4 signaling has been assessed in P19 cells using pTlx-Lux, a BMP-responsive reporter. All three genes are able to inhibit Bmp4 signaling. These data suggest that the different family members may act to modulate the action of TGFbeta family members during development.

The dangerousness of persons with delusional jealousy

Delusional jealousy is an important subject for forensic psychiatry because of its well-known association with violence, especially as directed toward spouses. In this article, we report a study of 20 individuals who suffered from delusional jealousy. Important biopsychosocial parameters, the relation between jealousy and aggression, and directions for future study are explored.

Dangerous delusions of misidentification of the self

Delusions of misidentification of the self involve radical misidentification of physical and/or psychological aspects of the self. These delusions have received limited attention from a phenomenological as well as from a forensic psychiatric perspective. In this article we present a series of four cases of dangerous delusional misidentification of the self and discuss important factors that may contribute to their dangerousness.