Overlapping and distinct expression domains of Zic2 and Zic3 during mouse gastrulation

The Zic genes are the vertebrate homologues of the Drosophila Odd-paired gene. Mutations in two of these genes are associated with human congenital genetic disorders. Mutation of human and mouse Zic2 is associated with holoprosencephaly which is caused by a defect of ventral forebrain development and mutation of human and mouse Zic3 is associated with a X-linked heterotaxy syndrome that results from a failure of left-right axis formation. The embryological role of the Zic genes in these disorders is not well understood. Here we show that both of these genes are expressed prior to and throughout gastrulation. The genes show some broad similarities in their expression domains. Both genes however are also uniquely expressed in some tissues and these unique domains correlate with regions that potentially play a role in the aetiology of the respective genetic disorders. During primitive streak stages Zic2 is expressed transiently and uniquely in the node and the head process mesendoderm. The head process is known to be required for the establishment or maintenance of the ventral forebrain, which is the region disrupted in holoprosencephaly. Zic3 is not expressed in the node during primitive streak stages but is expressed in and around the node beginning from the head fold stages of development. This expression of Zic3 correlates well with the first steps in the establishment of the left-right axis. We also examined the expression of the closely related gene, Zic1, and did not detect any transcripts in gastrulation stage embryos

Flux transfer event observation at Saturn's dayside magnetopause by the Cassini spacecraft

We present the first observation of a flux rope at Saturn's dayside magnetopause. This is an important result because it shows that the Saturnian magnetopause is conducive to multiple X-line reconnection and flux rope generation. Minimum variance analysis shows that the magnetic signature is consistent with a flux rope. The magnetic observations were well fitted to a constant-α force-free flux rope model. The radius and magnetic flux content of the rope are estimated to be 4600–8300 km and 0.2–0.8 MWb, respectively. Cassini also observed five traveling compression regions (remote signatures of flux ropes), in the adjacent magnetosphere. The magnetic flux content is compared to other estimates of flux opening via reconnection at Saturn

Low meprin alpha expression differentiates primary ovarian mucinous carcinoma from gastrointestinal cancers that commonly metastasise to the ovaries

Background: Currently, no specific immunohistochemical markers are available to differentiate primary mucinous epithelial ovarian cancer (MOC) from adenocarcinomas originating at other sites that have metastasised to the ovary, which may have an impact on patient management and prognosis. Aim: To investigate the expression of two intestinal markers, galectin 4 and meprin α, in mucinous carcinomas of the ovary and gastrointestinal tract. Methods: Using immunohistochemical analysis, the expression of galectin 4 and meprin α was investigated in 10 MOCs and in 38 mucinous adenocarcinomas of colon, pancreas, stomach and appendix, the most common sites of origin of ovarian metastases. Results: Total cytoplasmic galectin 4 expression was relatively consistent between the different carcinomas. Membranous meprin α expression was significantly lower in MOCs compared with gastrointestinal carcinomas. Moreover, meprin α expression showed greater discrimination between the ovarian and gastrointestinal carcinomas than the cytokeratins CK7 and CK20, the current standard immunohistochemical markers used to determine the tissue origin of mucinous carcinomas involving the ovaries. Conclusions: Meprin α is a useful additional marker in differentiating primary from secondary mucinous adenocarcinomas of the ovary