The zebrafish kidney marrow is considered to be the organ of definitive hematopoiesis, analogous to the mammalian bone marrow. We have sequenced 26,143 ESTs and isolated 304 cDNAs with putative full-length ORF from a zebrafish kidney marrow cDNA library. The ESTs formed 7,742 assemblies, representing both previously identified zebrafish ESTs (56%) and recently discovered zebrafish ESTs (44%). About 30% of these EST assemblies have orthologues in humans, including 1,282 disease-associated genes in the Online Mendelian Inheritance in Man (OMIM) database. Comparison of the effective and regulatory molecules related to erythroid functions across species suggests a good conservation from zebrafish to human. Interestingly, both embryonic and adult zebrafish globin genes showed higher homology to the human embryonic globin genes than to the human fetaladult ones, consistent with evo-devo correlation hypothesis. In addition, conservation of a whole set of transcription factors involved in globin gene switch suggests the regulatory network for such remodeling mechanism existed before the divergence of the teleost and the ancestor of mammals. We also carried out whole-mount mRNA in situ hybridization assays for 493 cDNAs and identified 80 genes (16%) with tissue-specific expression during the first five days of zebrafish development. Twenty-six of these genes were specifically expressed in hematopoietic or vascular tissues, including three previously unidentified zebrafish genes: coro1a, nephrosin, and dab2. Our results indicate that conserved genetic programs regulate vertebrate hematopoiesis and vasculogenesis, and support the role of the zebrafish as an important animal model for studying both normal development and the molecular pathogenesis of human blood diseases.

Sixty-one SARS coronavirus genomic sequences derived from the early, middle, and late phases of the severe acute respiratory syndrome (SARS) epidemic were analyzed together with two viral sequences from palm civets. Genotypes characteristic of each phase were discovered, and the earliest genotypes were similar to the animal SARS-like coronaviruses. Major deletions were observed in the Orf8 region of the genome, both at the start and the end of the epidemic. The neutral mutation rate of the viral genome was constant but the amino acid substitution rate of the coding sequences slowed during the course of the epidemic. The spike protein showed the strongest initial responses to positive selection pressures, followed by subsequent purifying selection and eventual stabilization.

In order to fully understand the physiological functions of adipose tissue, especially its secretory functions, and to provide a basis for the identification of novel obesity related genes, the gene expression profiling of human visceral adipose tissue was established by using cDNA array. 33P-labelled cDNA, derived from visceral adipose tissue total RNA, was hybridized to a cDNA array containing over 16,000 expressed sequence-tagged clones which represent human singleton genes. The expressed sequence tag (EST) was considered to be expressed in visceral adipose tissue when the ratio of signal to noise was greater than or equal to 2. The results were analyzed with bioinformatics. Totally, 8230 genes were found to be expressed in visceral adipose tissue with 5200 known genes and 3030 known ESTs. Most of 84 secretory proteins, 120 receptors, and 74 transcription factors expressed in adipose tissue were newly identified. Many appetite-regulating related peptides or receptors and some reproduction-related genes were first found to be expressed in adipose tissue. Eight autocrine/paracrine systems were described for the first time in the visceral adipose tissue. These results clearly demonstrate that the visceral adipose tissue has important secretory functions and there is a complex local autocrine/paracrine regulatory network. The present work suggests that the visceral adipose tissue is an important component of the neuroendocrine-immune network and plays an important role in regulating appetite not only via endocrine but also via autocrine/paracrine systems. The visceral adipose tissue might also play a role in regulating reproduction and sexual function.

Context: Mimecan, a secretory protein, belongs to a family of small leucine-rich proteoglycans (SLRPs). The physiological functions of mimecan have not been fully understood. Objective: We hypothesize that the mimecan gene expressed in the human pituitary and regulated by pituitary transcription factor-1 (Pit-1) might act as a marker for diagnosing pituitary tumors. Design: The clinical aspect of our work was a cross-sectional study. Setting and Patients: In total, 20 pituitary tumor samples were collected from January 1, 2002, to December 30, 2002, in Ruijin Hospital, Shanghai, China. Intervention: The number of pituitary tumors was limited. Collection of more pituitary tumor samples for additional observation will be necessary. Main Outcome Measures: The main outcomes were measured by Northern blot, in situ hybridization, immunohistochemical analysis, and so on. Results: The mimecan gene was expressed at a moderate level in the mouse pituitary gland by Northern blot analysis. Expression of mimecan mRNA and protein is also observed in the human anterior pituitary gland. Luciferase reporter analysis and electrophoretic mobility shift assays show that Pit-1 activates the human mimecan promoter through Pit-1 response element sites. In addition, our data also show that almost all the ACTH- or GH-positive pituitary tumors likely express mimecan protein, and only a portion of prolactin-, TSH-, FSH-, and LH-positive pituitary tumors express mimecan protein. Conclusions: This work provides insight into the regulating mechanism of mimecan in pituitary and suggests that mimecan may be an unidentified pituitary secretory protein, and certain pituitary cells secreting ACTH or GH also secrete mimecan. (J Clin Endocrinol Metab 90: 6657-6664, 2005)