Expression analysis of the Arabidopsis thaliana AtSpen2 gene, and its relationship with other plant genes encoding Spen proteins

Abstract Proteins of the Split ends (Spen) family are characterized by an N-terminal domain, with one or more RNA recognition motifs and a SPOC domain. In Arabidopsis thaliana, the Spen protein FPA is involved in the control of flowering time as a component of an autonomous pathway independent of photoperiod. The A. thaliana genome encodes another gene for a putative Spen protein at the locus At4g12640, herein named AtSpen2. Bioinformatics analysis of the AtSPEN2 SPOC domain revealed low sequence similarity with the FPA SPOC domain, which was markedly lower than that found in other Spen proteins from unrelated plant species. To provide experimental information about the function of AtSpen2, A. thaliana plants were transformed with gene constructs of its promoter region with uidA::gfp reporter genes; the expression was observed in vascular tissues of leaves and roots, as well as in ovules and developing embryos. There was absence of a notable phenotype in knockout and overexpressing lines, suggesting that its function in plants might be specific to certain endogenous or environmental conditions. Our results suggest that the function of Atspen2 diverged from that of fpa due in part to their different transcription expression pattern and divergence of the regulatory SPOC domain.

Clinical Features and Radiological Findings of Cystic Tumor of the Pancreas

PURPOSE: Most cystic tumors of the pancreas are composed of serous cystic tumor, mucinous cystic tumor, solid pseudo- papillary epithelial neoplasm (SPEN) and intraductal papillary mucinous tumor (IPMT). With advancements in diagnostic imaging, cystic lesions of the pancreas are being detected with increasing frequency; however, there is still difficulty determining the appropriate diagnostic and therapeutic plan. METHODS: A retrospective review was performed of 15 cases that underwent surgery for pancreatic cystic tumors in our department between July 1995 and August 2005. All 15 cases identified had their records and radiological images reviewed. Radiological findings were characterized and analyzed by one radiologist. RESULTS: The median age was 55.9 years. Six cases were male and nine were female. Common symptoms included: epigastirc pain 6/14 (43%) and palpable mass 2/14 (14%). The accuracy of the preop radiological diagnosis including abdominal CT and US was 12/15 (80%). One case of serous cystic tumor, one of chronic pancreatitis and one SPEN were misdiagnosed; the preoperative diagnosis for these cases was mucinous cystic tumor. Serous cystic tumors were seen with central calcification 2/3 (67%), external lobulation 3/3 (100%); however, the mucinous cystic tumors were seen with peripheral calcification 4/5 (80%), no external lobulation 5/5 (100%) by radiological evaluation. There was no calcification, but external lobulation was common in the IPMT. The SPEN had no specific radiological findings except for peripheral calcification. CONCLUSION: Future multicenter studies with endoscopic sonography and aspiration cytology is needed for improved accuracy of diagnosis.

Solid and Papillary Epithelial Neoplasm of the Pancreas in a Child: A case Report

Solid and papillary epithelial neoplasm (SPEN) of the pancreas is a rare tumor with low malignant potentiality that usually occurs in young females. Preoperative evaluation, especially radiologic tests, including ultrasonography and CT scan, is helpful in the diagnosis. These studies demonstrate a well-demarcated large mass with solid and cystic portions, frequently in the tail or body of the pancreas. Complete resection is usually curative, however local invasion and/or metastasis may occur. The authors report a case of a solid and papillary epithelial neoplasm of the pancreatic body in a 14-year old child at St. Benedict Hospital and review the literature.