Identification of Bombyx mori 14-3-3 orthologs and the interactor Hsp60

The 14-3-3 protein family consists of evolutionarily conserved, acidic 30 kDa proteins composed of seven isoforms named beta, gamma, epsilon, zeta, eta, theta, and sigma in mammalian cells. The dimeric complex of 14-3-3 isoforms, acting as a molecular adaptor, plays a central role in regulation of neuronal function. Since aberrant expression of 14-3-3 is identified in the brains of Alzheimer disease and Parkinson disease, a convenient insect model, if it is available, is highly valuable for studying a pathological role of 14-3-3 in neurodegeneration. Here, we identified the silkworm Bombyx mori 14-3-3 orthologs, zeta and epsilon isoforms highly homologous in amino acid sequences to the human 14-3-3zeta and 14-3-3epsilon. By Western blot, the expression of zeta and epsilon isoforms was identified at substantial levels in the first instar larva, markedly upregulated in the second instar larva, and the highest levels were maintained in the late stage of larva, the pupa, and the adult. Furthermore, by protein overlay and immunoprecipitation, we identified Hsp60 as a 14-3-3-binding partner. The 14-3-3 proteins interacted with the N-terminal fragment of Hsp60. The 14-3-3zeta and epsilon isoforms, along with Hsp60, were expressed widely with overlapping distribution in larval and adult tissues, including brain, fat body, silk gland, Malpighian tube, midgut, ovary, testis, antenna, and pheromone gland. These observations suggest that a molecular adaptor 14-3-3 and a molecular chaperone Hsp60 cooperate to achieve a wide range of cellular functions in B. mori.

Functional analysis of four Gloverin-like genes in the silkworm, Bombyx mori

To identify genes involved in the innate immunity of the silkworm Bombyx mori, we constructed a cDNA library from the fat body of Escherichia coli-challenged B. mori larvae. Based on the expressed sequence tag (EST) data and whole genome shotgun sequence analysis, we found four Gloverin-like genes, BmGlov1-4, in the Bombyx genome. Northern blot and RT-PCR analysis showed that BmGlov1-4 were induced in the larval fat body after an immune challenge by the injection of E. coli; however, less induction was observed after the injection of a yeast Candida albicans. In silico sequence analysis revealed the presence of a motif homologous to NF-kappaB binding site in the upstream region of each BmGlov gene. Moreover, we expressed recombinant BmGlov1-4 proteins using the baculovirus expression system, and found that all the recombinant BmGlov1-4 significantly inhibited the growth of E. coli.

Developmentally synchronized expression of two Bombyx mori Piwi subfamily genes, SIWI and BmAGO3 in germ-line cells

The Piwi subfamily proteins and their partner, Piwi-interacting RNAs (piRNAs), play an important roles in germ-line development and silencing of selfish DNA elements. To date, however, the developmental expression profiles of the Piwi subfamily genes are poorly known. In this study, we examined the expression profiles of two Bombyx mori Piwi subfamily genes, silkworm Piwi (SIWI) and BmAGO3, which are possible partners of Bombyx piRNA-like small RNAs we recently identified in B. mori germ-line cells. Quantitative reverse transcription-polymerase chain reaction analyses demonstrated that these two genes were abundantly expressed in the larval testis, pupal ovary, and adult eggs, suggesting that they might be involved in spermatogenesis and oogenesis in Bombyx. Notably, developmental expression patterns of SIWI and BmAGO3 were remarkably similar. Collectively, our results suggest that SIWI and BmAGO3 may cooperate in an unknown pathway during the development of B. mori germ-line cells.

Verification of elicitor efficacy of lipopolysaccharides and peptidoglycans on antibacterial peptide gene expression in Bombyx mori

We verified the efficacy of lipopolysaccharide (LPS) in activating the cecropin B gene (CecB) in an immune-competent Bombyx mori cell line. Strong activation of CecB by the LPSs from Escherichia coli, Pseudomonas aeruginosa, and Salmonella minnesota were completely eliminated after digestion of the LPSs with muramidase. The results clearly indicate that a polymer form of PGN in the LPSs elicited CecB. An oligonucleotide microarray screen revealed that none of the 16,000 genes on the array were activated by LPS in the cells. In contrast, E. coli PGN strongly elicited five antibacterial peptide genes and numerous other genes, and PGN from Micrococcus luteus activated only several genes. Semi-quantitative RT-PCR revealed that all antibacterial genes activated by both PGNs, but the extents were 10-100 times higher with E. coli PGN. Similarly, higher elicitor activity of E. coli than M. luteus was indicated using peptidoglycan recognition protein gene, which is involved in pro-phenol oxidase cascade.

Identification and characterization of a novel sericin gene expressed in the anterior middle silk gland of the silkworm Bombyx mori

Sericin is a group of proteins expressed in the middle silk gland that covers the surface of fibroin in the cocoon filament of Bombyx mori. Sericin consists of several serine-rich proteins with different molecular masses. Sericin A is one of the proteins and is produced in the anterior portion of the middle silk gland. To identify the gene coding for the protein, we determined the primary structures of its partial peptides, and the gene was searched using the silkworm genomic databases. Three contigs containing the corresponding nucleotide sequences were identified and categorized as one group. The gene structure covering the 5' flanking and the 3' end was determined by PCR fragments from genomic DNA, RT-PCR, and 5' and 3' RACE. The amino acid sequence deduced from the nucleotide sequence mainly consists of two serine-rich regions of 86-amino acid motif and 8-amino acid repeated sequence. The expression of the gene is limited to the anterior and middle parts of the middle silk gland. In addition, because the sericin gene appeared different from the sericin 1 and 2 genes reported earlier, we designated the newly discovered gene as sericin 3.

ERK- and JNK-dependent signaling pathways contribute to Bombyx mori nucleopolyhedrovirus infection

Mitogen-activated protein kinases (MAPKs) often play important roles in virus infection. To explore intracellular signaling pathways induced by baculovirus infection, we examined the involvement of MAPKs in Bombyx mori nucleopolyhedrovirus (BmNPV) infection of BmN cells. We found that specific inhibitors of extracellular signal-regulated kinase (ERK) kinase and c-Jun NH(2)-terminal kinase (JNK) significantly reduced occlusion body (OB) formation and budded virus (BV) production. Next, we quantified OB and BV production after applying the inhibitors at different times postinfection (p.i.). The inhibitors significantly reduced OB and BV production to various extents when applied at 12 h p.i., indicating that the reduction of BmNPV infectivity by these inhibitors occurs at the late stage of infection. Also, we observed that these inhibitors markedly repressed or deregulated the expression of delayed early, late, and very late gene products. Western blot analysis using phospho-MAPK-specific antibodies showed that ERK and JNK were activated at the late stage of BmNPV infection. In addition, the magnitude and pattern of MAPK activation were dependent on the multiplicity of infection. To verify the effects of the inhibitors on BmNPV infection, we also attempted to knock down the B. mori genes BmErk and BmJnk, which encode ERK and JNK, respectively. Knockdown of BmErk and BmJnk resulted in the reduced production of OBs and BVs, confirming that BmERK and BmJNK are involved in the BmNPV infection process. Taken together, these results indicate that the activation of MAPK signaling pathways is required for efficient infection by BmNPV.

Identification of the female-determining region of the W chromosome in Bombyx mori

The W chromosome of the silkworm Bombyx mori is devoid of functional genes, except for the putative female-determining gene (Fem). To localize Fem, we investigated the presence of W-specific DNA markers on strains in which an autosomal fragment containing dominant marker genes was attached to the W chromosome. We produced new W-chromosomal fragments from the existing Zebra-W strain (T(W;3)Ze chromosome) by X-irradiation, and then carried out deletion mapping of these and sex-limited yellow cocoon strains (T(W;2)Y-Chu, -Abe and -Ban types) from different Japanese stock centers. Of 12 RAPD markers identified in the normal W chromosomes of most silkworm strains in Japan, the newly irradiated W(B-YL-YS)Ze chromosome contained three, the T(W;2)Y-Chu chromosome contained six, and the T(W;2)Y-Abe and -Ban chromosomes contained only one (W-Rikishi). To investigate the ability of the reduced W-chromosome translocation fragments to form heterochromatin bodies, which are found in nuclei of normal adult female sucking stomachs, we examined cells of the normal type p50 strain and the T(W;2)Y-Chu and -Abe strains. A single sex heterochromatin body was found in nuclei of p50 females, whereas we detected only small sex heterochromatin bodies in the T(W;2)Y-Chu strain and no sex heterochromatin body in the T(W;2)Y-Abe strain. Since adult females of all strains were normal and fertile, we conclude that only extremely limited region, containing the W-Rikishi RAPD sequence of the W chromosome, is required to determine femaleness. Based on a comparison of the normal W-chromosome and 7 translocation and W-deletion strains we present a map of Fem relative to the 12 W-specific RAPD markers.

End-sequencing and characterization of silkworm (Bombyx mori) bacterial artificial chromosome libraries

Background

We performed large-scale bacterial artificial chromosome (BAC) end-sequencing of two BAC libraries (an EcoRI- and a BamHI-digested library) and conducted an in silico analysis to characterize the obtained sequence data, to make them a useful resource for genomic research on the silkworm (Bombyx mori).

Results

More than 94000 BAC end sequences (BESs), comprising more than 55 Mbp and covering about 10.4% of the silkworm genome, were sequenced. Repeat-sequence analysis with known repeat sequences indicated that the long interspersed nuclear elements (LINEs) were abundant in BamHI BESs, whereas DNA-type elements were abundant in EcoRI BESs. Repeat-sequence analysis revealed that the abundance of LINEs might be due to a GC bias of the restriction sites and that the GC content of silkworm LINEs was higher than that of mammalian LINEs. In a BLAST-based sequence analysis of the BESs against two available whole-genome shotgun sequence data sets, more than 70% of the BESs had a BLAST hit with an identity of ≥ 99%. About 14% of EcoRI BESs and about 8% of BamHI BESs were paired-end clones with unique sequences at both ends. Cluster analysis of the BESs clarified the proportion of BESs containing protein-coding regions.

Conclusion

As a result of this characterization, the identified BESs will be a valuable resource for genomic research on Bombyx mori, for example, as a base for construction of a BAC-based physical map. The use of multiple complementary BAC libraries constructed with different restriction enzymes also makes the BESs a more valuable genomic resource. The GenBank accession numbers of the obtained end sequences are DE283657–DE378560.

Control of juvenile hormone biosynthesis in Bombyx mori: cloning of the enzymes in the mevalonate pathway and assessment of their developmental expression in the corpora allata

We have isolated the cDNAs of all enzymes involved in the mevalonate pathway portion of the juvenile hormone (JH) biosynthetic pathway in Bombyx mori, i.e., those responsible for the formation of farnesyl diphosphate from acetyl-CoA. There is a single gene encoding each enzyme of this pathway, with the exception of farnesyl diphosphate synthase (FPPS), for which we identified three homologs. All but two of these enzymes are expressed almost exclusively in the corpora allata (CA), as indicated by quantitative RT-PCR analyses. Phosphomevalonate kinase (MevPK) was expressed in many tissues, including the CA. In day 2 4th instars, FPPS1 expression was detected primarily in the Malpighian tubules, but expression of the structurally related FPPS2 and FPPS3 occurred mainly in the CA. Since FPPS3 transcripts were 55 times less abundant than those of FPPS2, the latter is expected to play a major role in JH biosynthesis at this stage. Studies on the developmental expression of these enzymes in the CA showed that the levels of all transcripts were high during the 4th instar larvae, a stage at which in vitro JH biosynthesis was high. However, the transcripts of all the mevalonate enzymes declined to low levels and JH acid O-methyltransferase (JHAMT) transcript disappeared by day 3 when CA ceased JH production after the final larval molt. The CA did not synthesize JH during the pupal stage, coincident with the limited expression of mevalonate kinase, phosphomevalonate kinase, diphosphomevalonate kinase and isopentenyl diphosphate isomerase, and the inactivation of the JHAMT gene. Only female CA produced JH in the adult stage, a feature associated with the re-expression of JHAMT in female but little in male adult CA. Altogether, our results point to a relationship between JH biosynthesis and expression of most JH biosynthetic enzymes in the CA.

Molecular cloning and expression of two novel beta-N-acetylglucosaminidases from silkworm Bombyx mori

Beta-N-acetylglucosaminidase is a major glycosidase involved in several physiological processes, such as fertilization, metamorphosis, glycoconjugate degradation, and glycoprotein biosynthesis in insects. A search using the Bombyx mori cDNA database revealed the existence of two putative beta-N-acetylglucosaminidase genes. Their full-length cDNAs were cloned by rapid amplification of cDNA ends and polymerase chain reaction using specific primers, and named BmGlcNAcase1 and BmGlcNAcase2. A BLAST search revealed that BmGlcNAcase1 and BmGlcNAcase2 are homologous to a beta-subunit homolog encoded by Drosophila melanogaster HEXO2 and the Spodoptera frugiperda beta-N-acetylglucosaminidase gene respectively. The recombinant proteins of BmGlcNAcase1 and BmGlcNAcase2 without putative transmembrane domains were expressed in the yeast Pichia pastoris. Both enzymes showed broad substrate specificity, and cleaved terminal N-acetylglucosamine residues from the alpha-3 and alpha-6 branches of a biantennary N-glycan substrate, and also hydrolyzed chitotriose to chitobiose.

Lepidopteran ortholog of Drosophila breathless is a receptor for the baculovirus fibroblast growth factor

The Bombyx mori nucleopolyhedrovirus (BmNPV) encodes a gene homologous to the mammalian fibroblast growth factor (FGF) family. We report the cloning of B. mori and Spodoptera frugiperda orthologous genes (Bmbtl and Sfbtl, respectively) of Drosophila melanogaster breathless (btl) encoding a receptor for Branchless/FGF and show that these genes encode the receptor for a baculovirus-encoded FGF (vFGF). Sequence analysis showed that BmBtl is composed of 856 amino acid residues, which potentially encodes a 97.3-kDa polypeptide and shares structural features and sequence similarities with the FGF receptor family. Reverse transcription-PCR experiments showed that Bmbtl was abundantly expressed in the trachea and midgut in B. mori larvae, with moderate expression observed in the hemocytes and the B. mori cultured cell line BmN. We generated Sf-9 cells that stably expressed His-tagged BmBtl. Western blot analysis revealed that BmBtl was an approximately 110-kDa protein. Immunoprecipitation experiments showed that BmNPV vFGF markedly phosphorylated BmBtl in Sf-9 cells. In addition, we found that BmBtl overexpression enhanced the migration activity for BmNPV vFGF. Furthermore, we generated Sf-9 cells in which Sfbtl was knocked down by transfection with double-strand RNA-expressing plasmids. In these cells, cell motility triggered by vFGF was markedly reduced. These results strongly suggest that the Btl orthologs, BmBtl and SfBtl, are the receptors for vFGF, which mediate vFGF-induced host cell chemotaxis.

Cloning and characterization of insect arylalkylamine N-acetyltransferase from Bombyx mori

Arylalkylamine N-acetyltransferase (AANAT) catalyzes N-acetylation of arylarkylamines. A cDNA of Bombyx mori insect AANAT (Bm-iAANAT) was found by searching an expressed-sequence tag (EST) database of B. mori (SilkBase). The cDNA encoded a 261 amino acid protein. The mRNA of Bm-iAANAT was expressed in eggs, larvae, adults and various tissues. Recombinant Bm-iAANAT protein was expressed in Sf9 cells by a baculovirus expression system. The AANAT activity of Bm-iAANAT was inhibited by high concentrations (over 0.01 mM) of tryptamine used as a substrate. The Bm-iAANAT acetylated tryptamine, serotonin, dopamine, octopamine, tyramine and norepinephrine. This is the first report of a cloned AANAT that acetylated norepinephrine. These results suggest that Bm-iAANAT is a novel member of insect AANAT family with unique kinetic properties and a broad substrate range.

SAGE analysis of early oogenesis in the silkworm, Bombyx mori

To identify genes involved in the differentiation of Bombyx cystoblast, we constructed two 3' long serial analysis of gene expression (Long SAGE) libraries from stage 1-3 or stage 2-3 egg chambers and compared their gene expression profiles. In both libraries, the most frequent tags were derived from the same novel transcript. The transcript does not have any open reading frame capable of encoding a protein with over 100 amino acids in length. RNA blot analysis revealed that this transcript is specifically and abundantly expressed in the Bombyx ovary, mainly the germ line cells in the ovarioles. These results suggest that Bombyx oogenesis may be regulated by a previously unidentified non-coding RNA. Comparison of the gene expression profiles between the stage 1-3 and stage 2-3 egg chamber libraries revealed that 272 tags were significantly more abundant in stage 1-3 egg chambers (p<0.05 and at least two-fold change) than in library 2. Among the differentially expressed transcripts were the sequences that correspond to ATP synthase subunit d (3.1-fold enriched) and ATP synthase coupling factor 6 (9.1-fold enriched), suggesting that they are involved in regulation of cell cycle of cystocytes.

Neverland is an evolutionally conserved Rieske-domain protein that is essential for ecdysone synthesis and insect growth

Steroid hormones mediate a wide variety of developmental and physiological events in multicellular organisms. During larval and pupal stages of insects, the principal steroid hormone is ecdysone, which is synthesized in the prothoracic gland (PG) and plays a central role in the control of development. Although many studies have revealed the biochemical features of ecdysone synthesis in the PG, many aspects of this pathway have remained unclear at the molecular level. We describe the neverland (nvd) gene, which encodes an oxygenase-like protein with a Rieske electron carrier domain, from the silkworm Bombyx mori and the fruitfly Drosophila melanogaster. nvd is expressed specifically in tissues that synthesize ecdysone, such as the PG. We also show that loss of nvd function in the PG causes arrest of both molting and growth during Drosophila development. Furthermore, the phenotype is rescued by application of 20-hydroxyecdysone or the precursor 7-dehydrocholesterol. Given that the nvd family is evolutionally conserved, these results suggest that Nvd is an essential regulator of cholesterol metabolism or trafficking in steroid synthesis across animal phyla.

Isolation and Characterization of a Novel Human Radiosusceptibility Gene, NP95

The murine nuclear protein Np95 has been shown to underlie resistance to ionizing radiation and other DNA insults or replication arrests in embryonic stem (ES) cells. Using the databases for expressed sequenced tags and a two-step PCR procedure, we isolated human NP95, the full-length human homologue of the murine Np95 cDNA, which consists of 4,327 bp with a single open reading frame (ORF) encoding a polypeptide of 793 amino acids and 73.3% homology to Np95. The ORF of human NP95 cDNA is identical to the UHRF1 (ubiquitin-like protein containing PHD and RING domain 1). The NP95 gene, assigned to 19p13.3, consists of 18 exons, spanning 60 kb. Several stable transformants from HEK293 and WI-38 cells that had been transfected with the antisense NP95 cDNA were, like the murine Np95-knockout ES cells, more sensitive to X rays, UV light and hydroxyurea than the corresponding parental cells. In HEK293 cells, the lack of NP95 did not affect the activities of topoisomerase IIalpha, whose expression had been demonstrated to be regulated by the inverted CCAAT box binding protein of 90 kDa (ICBP90) that closely resembles NP95 in amino acid sequence and in cDNA but differs greatly in genomic organization. These findings collectively indicate that the human NP95 gene is the functional orthologue of the murine Np95 gene.

Protein Composition of Silk Filaments Spun under Water by Caddisfly Larvae

Silk fiber produced by the larvae of Trichoptera (caddisflies) and Lepidoptera (moths and butterflies) is composed of two filaments embedded in a layer of glue proteins. In an aerial environment Lepidoptera spin silk filaments assembled from heavy chain fibroin (H-fibroin), light chain fibroin (L-fibroin), and the glycoprotein P25. The silk filament of caddisflies, which is produced and persists in water, contained homologues of H-fibroin (>500 kDa) and L-fibroin (25 kDa) but not of P25. The amphiphilic nature of H-fibroin and its high content of charged amino acids probably facilitate the secretion and storage of a covalently linked L-fibroin/H-fibroin dimer in the absence of P25. Several types of short amino acid motifs were arranged in orderly fashion in the regularly reiterated repeats that made up more than 95% of the length of H-fibroin. The H-fibroins of Hydropsyche angustipennis and Limnephilus decipiens from different caddisfly suborders contained GPXGX, SXSXSXSX, and GGX motifs such as the lepidopteran and spider silks but differed from them by a lack of poly(A) and poly(GA) motifs. H-fibroins of both caddisfly species harbored a conserved repeat of 31 residues but were distinguished by a few species-specific motifs and their organization in higher order repeats. Structural differences may be related to the silk function as a catching net in H. angustipennis and a stitching fiber in L. decipiens.

The female-killing chromosome of the silkworm, Bombyx mori, was generated by translocation between the Z and W chromosomes

Bombyx mori is a female-heterogametic organism (female, ZW; male, ZZ) that appears to have a putative feminizing gene (Fem) on the W chromosome. The paternally transmitted mutant W chromosome, Df(p ( Sa ) + ( p )W + ( od ))Fem, derived from the translocation-carrying W chromosome (p ( Sa ) + ( p )W + ( od )), is inert as femaleness determinant. Moreover, this Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome has been thought to have a female-killing factor because no female larvae having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome are produced. Initially, to investigate whether the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains any region of the W chromosome or not, we analyzed the presence or absence of 12 W-specific RAPD markers. The Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contained 3 of 12 W-specific RAPD markers. These results strongly indicate that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains the region of the W chromosome. Moreover, by using phenotypic and molecular markers, we confirmed that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is connected with a partially deleted Z chromosome and that this fused chromosome behaves as a Z chromosome during male meiosis. Furthermore, we demonstrated that the ZZW-type triploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is viable. Therefore, we concluded that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome does not have a female-killing factor but that partial deletion of the Z chromosome causes the death of the ZW-type diploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome. Additionally, our results of detailed genetic analyses strongly indicate that the female-killing chromosome composed of the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome and deleted Z chromosome was generated by translocation between the Z chromosome and the translocation-carrying W chromosome, p ( Sa ) + ( p )W + ( od ).

Isolation and characterization of sex chromosome rearrangements generating male muscle dystrophy and female abnormal oogenesis in the silkworm, Bombyx mori

In deletion-mapping of W-specific RAPD (W-RAPD) markers and putative female determinant gene (Fem), we used X-ray irradiation to break the translocation-carrying W chromosome (W( Ze )). We succeeded in obtaining a fragment of the W( Ze ) chromosome designated as Ze (W), having 3 of 12 W-RAPD markers (W-Bonsai, W-Yukemuri-S, W-Yukemuri-L). Inheritance of the Ze (W) fragment by males indicates that it does not include the Fem gene. On the basis of these results, we determined the relative positions of W-Yukemuri-S and W-Yukemuri-L, and we narrowed down the region where Fem gene is located. In addition to the Ze (W) fragment, the Z chromosome was also broken into a large fragment (Z(1)) having the +( sch ) (1-21.5) and a small fragment (Z(2)) having the +( od ) (1-49.6). Moreover, a new chromosomal fragment (Ze (W)Z(2)) was generated by a fusion event between the Ze (W) and the Z(2) fragments. We analyzed the genetic behavior of the Z(1) fragment and the Ze (W)Z(2) fragment during male (Z/Z(1) Ze (W)Z(2)) and female (Z(1) Ze (W)Z(2)/W) meiosis using phenotypic markers. It was observed that the Z(1) fragment and the Z or the W chromosomes separate without fail. On the other hand, non-disjunction between the Ze (W)Z(2) fragment and the Z chromosome and also between the Ze (W)Z(2) fragment and the W chromosome occurred. Furthermore, the females (2A: Z/Ze (W)Z(2)/W) and males (2A: Z/Z(1)) resulting from non-disjunction between the Ze (W)Z(2) fragment and the W chromosome had phenotypic defects: namely, females exhibited abnormal oogenesis and males were flapless due to abnormal indirect flight muscle structure. These results suggest that Z(2) region of the Z chromosome contains dose-sensitive gene(s), which are involved in oogenesis and indirect flight muscle development.

Stat5 expression predicts response to endocrine therapy and improves survival in estrogen receptor-positive breast cancer

Constitutively activated signal transducers and activators of transcription (Stats), in particular Stat3 and Stat5, have been demonstrated to directly contribute to oncogenesis by stimulating cell proliferation and preventing apoptosis in various cancers. Stat3 is essential in mammary gland epithelial cell apoptosis and involution, whereas Stat5 is well established as a key factor in mammary epithelial cell growth and differentiation. Crosstalk between Stats and estrogen receptor (ER) has been demonstrated by several laboratories and we have focused on the role of Stat5 in ER-positive breast cancer. Using immunohistochemical techniques, we examined the expression of Stat3 and Stat5 in 517 human breast cancer tissues and analyzed their significance for prognosis and prediction of response to endocrine therapy. Stat5 expression was significantly correlated with histological grade (P<0.0001), ER (P=0.02), and progesterone receptor (P=0.026) expression. There was no difference between Stat3 expression and clinicopathological factors. In 346 patients with ER-positive breast cancer, patients with Stat5 positive tumors had significantly increased overall survival (P=0.0009) in multivariate analysis. There were 70 patients who received endocrine therapy as first-line treatment for metastatic breast cancer at relapse. The patients whose primary breast tumors were Stat5 positive, had significantly better response to endocrine therapy (P=0.04), and longer survival after relapse (P=0.0003), than those whose tumors were Stat5 negative. The present study demonstrates for the first time that Stat5 is a predictive factor for endocrine therapy response and a strong prognostic molecular marker in ER-positive breast cancer. Our data suggest that the expression of Stat5 is helpful in selecting patients who may benefit from endocrine therapy.

Purification, kinetic characterization, and molecular cloning of a novel enzyme, ecdysteroid 22-kinase

This is the first report succeeding in the isolation and characterization of an enzyme and its gene involved in the phosphorylation of a steroid hormone. It has been demonstrated that ecdysteroid 22-phosphates in insect ovaries, which are physiologically inactive, serve as a "reservoir" that supplies active free ecdysteroids during early embryonic development and that their dephosphorylation is catalyzed by a specific enzyme, ecdysteroid-phosphate phosphatase (Yamada, R., and Sonobe, H. (2003), J. Biol. Chem. 278, 26365-26373). In this study, ecdysteroid 22-kinase (EcKinase) was purified from the cytosol of the silkworm Bombyx mori ovaries to about 1,800-fold homogeneity in six steps of column chromatography and biochemically characterized. Results obtained indicated that the reciprocal conversion of free ecdysteroids and ecdysteroid 22-phosphates by two enzymes, EcKinase and ecdysteroid-phosphate phosphatase, plays an important role in ecdysteroid economy of the ovary-egg system of B. mori. On the basis of the partial amino acid sequence obtained from purified EcKinase, the nucleotide sequence of the cDNA encoding EcKinase was determined. The full-length cDNA of EcKinase was composed of 1,850 bp with an open reading frame encoding a protein of 386 amino acid residues. The cloned cDNA was confirmed to encode the functional EcKinase using the transformant harboring the open reading frame of EcKinase. A data base search showed that EcKinase has an amino acid sequence characteristic of phosphotransferases, in that it harbors Brenner's motif and putative ATP binding sites, but there are no functional proteins that share high identity with the amino acid sequence of EcKinase.

Polycalin (chlorophyllid A binding protein): a novel, very large fluorescent lipocalin from the midgut of the domestic silkworm Bombyx mori L

We studied a protein from the midgut of the silkworm Bombyx mori characterized by its ability to bind the prosthetic group of chlorophyll, that confers fluorescent properties to this protein. Several techniques, 2D electrophoresis purification, MS-MS and Maldi-TOF peptide sequencing, RT-PCR and nucleotide sequencing were used to obtain the nucleotide sequence and the deduced amino acid sequence. The coding sequence was compared to the gene sequence to define the number and size of introns and exons. The gene spanned 45.5 kb of DNA and consisted of 46 exons. The cDNA encoded a protein of 2721 amino acids. The protein was identified as a lipocalin with novel features. Most lipocalins are proteins with high affinity to small lipophilic molecules, with a molecular size in the 25 kDa range and a well conserved tertiary structure. The apoprotein described here revealed 15 lipocalin like structures, in line. We called this protein a polycalin (pentadecacalin).

SPODOBASE: an EST database for the lepidopteran crop pest Spodoptera

Background

The Lepidoptera Spodoptera frugiperda is a pest which causes widespread economic damage on a variety of crop plants. It is also well known through its famous Sf9 cell line which is used for numerous heterologous protein productions. Species of the Spodoptera genus are used as model for pesticide resistance and to study virus host interactions. A genomic approach is now a critical step for further new developments in biology and pathology of these insects, and the results of ESTs sequencing efforts need to be structured into databases providing an integrated set of tools and informations.

Description

The ESTs from five independent cDNA libraries, prepared from three different S. frugiperda tissues (hemocytes, midgut and fat body) and from the Sf9 cell line, are deposited in the database. These tissues were chosen because of their importance in biological processes such as immune response, development and plant/insect interaction. So far, the SPODOBASE contains 29,325 ESTs, which are cleaned and clustered into non-redundant sets (2294 clusters and 6103 singletons). The SPODOBASE is constructed in such a way that other ESTs from S. frugiperda or other species may be added. User can retrieve information using text searches, pre-formatted queries, query assistant or blast searches. Annotation is provided against NCBI, UNIPROT or Bombyx mori ESTs databases, and with GO-Slim vocabulary.

Conclusion

The SPODOBASE database provides integrated access to expressed sequence tags (EST) from the lepidopteran insect Spodoptera frugiperda. It is a publicly available structured database with insect pest sequences which will allow identification of a number of genes and comprehensive cloning of gene families of interest for scientific community. SPODOBASE is available from URL:

Cloning and expression analysis of takeout/JHBP family genes of silkworm, Bombyx mori

A Bombyx EST cDNA database was searched using the Drosophila takeout gene and nine cDNAs were obtained. The homology search suggested that these genes are widespread in insects and organize a large gene family, and that they have hydrophobic ligands. A phylogenetic tree indicated that the genes are first divided into two large groups, juvenile hormone binding protein and other protein genes, and the latter group diversified within a short time at an early stage. The expression study of five Bombyx genes indicated that they are expressed in various tissues and are regulated by development and feeding conditions. The Bombyx genes might have roles related to the regulation of metabolism, growth or development related to nutritional conditions.

Retroperitoneoscopic Radical Nephrectomy in Obese Patients: Outcomes and Considerations

OBJECTIVE

To determine whether obesity is associated with surgical outcome in Japanese patients undergoing retroperitoneoscopic radical nephrectomy (RRN).

PATIENTS AND METHODS

Between November 1999 and March 2005, we performed 98 RRN procedures for patients with renal cell carcinoma. Patients with a body mass index (BMI) of 25.0 or more were defined as obese (group A, n=33) and those with a BMI of <25.0 were defined as non-obese (group B, n=65), in accordance with the criteria of the Japan Society for the Study of Obesity. Patient background, degree of surgical invasiveness, and period of convalescence were compared between groups A and B.

RESULTS

No statistically significant differences were observed between the groups in terms of age, gender, tumor laterality, tumor size, and time until resumption of oral intake and ambulation. However group A had a significantly longer insufflation time (172.1 vs. 137.4 min), greater blood loss (195.3 vs. 48.4 ml) and higher renal specimen weight (440.0 vs. 306.0 g) than group B.

CONCLUSION

Obesity is not a factor that affects patient eligibility for RRN, but is a risk factor for longer insufflation time and greater blood loss.