Structural divergence among genomes of closely related baculoviruses and its implications for baculovirus evolution

Baculoviruses are members of a large, well-characterized family of dsDNA viruses that have been identified from insects of the orders Lepidoptera, Hymenoptera, and Diptera. Baculovirus genomes from different virus species generally exhibit a considerable degree of structural diversity. However, some sequenced baculovirus genomes from closely related viruses are structurally very similar and share overall nucleotide sequence identities in excess of 95%. This review focuses on the comparative analysis of partial and complete nucleotide sequences from two groups of closely related baculoviruses with broad host ranges: (a) group I multiple nucleopolyhedroviruses (MNPVs) from a cluster including Autographa californica (Ac)MNPV, Rachiplusia ou (Ro)MNPV, and Plutella xylostella (Plxy)MNPV; and (b) granuloviruses (GVs) from a cluster including Xestia c-nigrum (Xecn)GV and Helicoverpa armigera (Hear)GV. Even though the individual viruses in these clusters share high nucleotide sequence identities, a significant degree of genomic rearrangement (in the form of insertions, deletions, and homologous recombination resulting in allelic replacement) is evident from alignments of their genomes. These observations suggest an important role for recombination in the early evolution and biological characteristics of baculoviruses of these two groups.     

三株烟草天蛾新细胞系的生长特性及重组蛋白表达

从尚未涉及的昆虫种类中建立新的细胞系能为基础研究和生物技术应用提供重要资源。本实验通过细胞培养技术, 建立了3株来源于鳞翅目昆虫烟草天蛾Manduca sexta卵组织的新细胞系, 分别命名为QB-Ms1-8, QB-Ms2-2和QB-Ms2-7。这3株细胞已经培养在TNM-FH培养基中, 28℃条件下传代培养了约50代, 大部分细胞呈梭形, 细胞群体倍增时间分别为51, 31和49 h。虽然这3株细胞系对苜蓿银纹夜蛾核型多角体病毒（Autographa californica multiple nuclear polyhedrosis virus, AcMNPV）不够敏感, 侵染后96 h感染率在33%~40%之间, 但是QB-Ms2-2细胞与BTI-Tn5B1-4细胞比较, 分泌型碱性磷酸酶（SEAP）活性表达更高。本研究从建立的3株烟草天蛾新细胞系中筛选出SEAP高表达的细胞系QB-Ms2-2, 为进一步细胞克隆和筛选提供了新资源。     

Genetic diversity of the Pichia membranifaciens strains revealed from rRNA gene sequencing and electrophoretic karyotyping, and the proposal of Candida californica comb. nov

The genetic diversity of the types or authentic strains of 20 facultative synonyms of Pichia membranifaciens (E.C. Hansen) E.C. Hansen was revealed on the basis of large-subunit (26S) rDNA D1/D2 domain and internal transcribed spacer region sequencing and electrophoretic karyotyping. At least five separate species were recognized among the strains studied. Fourteen strains were confirmed to belong to P. membranifaciens. Strain CBS 241, an authentic strain of Zygosaccharomyces chevalieri Guilliermond var. fermentati Saito, should be assigned to Pichia manshurica Santa María. Strain CBS 243, an authentic strain of Zygopichia chiantigiana Castelli, is conspecific with CBS 2287, the type strain of Pichia fluxuum (Phaff & Knapp) Kreger-van Rij. Strain CBS 1367, the type of Zygosaccharomyces bisporus Anderson, belongs to Pichia kluyveri Bedford var. kluyveri. Strain CBS 989, the type of Cryptococcus californicus Anderson & Skinner, represents a distinct species, for which a new combination, Candida californica comb. nov., is proposed. The taxonomic status of strains CBS 189, the type of Pichia calliphorae Kl?cker, and CBS 214, the type of Pichia derossii Castelli, remain to be studied further. Their D1/D2 sequences and chromosomal DNA banding patterns were similar to those of P. membranifaciens, but their internal transcribed spacer sequences differed significantly.     

Effect of Seed Source, Topsoil Removal, and Plant Neighbor Removal on Restoring California Coastal Prairies

Grasslands are hot spots of biodiversity but are now widely threatened by changes in patterns of disturbances, such as grazing and fire regimes, exotic species invasions, and cultivation. The goal of this experiment was to find the most appropriate combination of treatments to reintroduce Danthonia californica, a formerly dominant perennial bunchgrass, into degraded California coastal prairies. Danthonia californica was sown from seed and transplanted at two sites and at two grazing intensities (grazed/ungrazed) in a multifactorial experiment testing the effects of (1) local versus nonlocal seed sources; (2) topsoil removal; and (3) reduction of plant neighbors. Seed emergence was very low, suggesting that transplanting may be a better option to reintroduce D. californica. Although transplants grown from nonlocal seeds survived better initially at both sites, transplants from local seeds had higher survival after 1.5 year at one site. This suggests that short‐term plant establishment studies may be misleading. Topsoil removal greatly enhanced transplant survival, and neighbor removal primarily increased transplant growth. Our results suggest that removing topsoil prior to transplanting seedlings grown from local seeds is the most promising method to reintroduce D. californica. However, the benefits of removing topsoil to provide safe sites for plant establishment should be weighed carefully against potential negative effects on the native seed bank and microbial communities on a site‐specific basis .     

Comparison of oligosaccharide processing among various insect cell lines expressing a secreted glycoprotein

Summary The processing of the N-linked oligosaccharide modifying a secreted alkaline phosphatase glycoprotein (SEAP) expressed with a recombinantAutographa californica nuclear polyhedrosis virus was evaluated in insect cell lines established fromSpodoptera frugiperda, Trichoplusia ni, andMamestra brassicae. Studies with Endoglycosidase H (Endo H), which removes high-mannose oligosaccharides, revealed that 79% of the intracellular SEAP produced in theM. brassicae-derived MB0503 cell line was Endo H resistant. The commonly usedS. frugiperda Sf21 and Sf9 cell lines produced 44 and 21% Endo H-resistant intracellular SEAP, respectively. Detection of oligosaccharide moieties with lectins, which selectively recognize terminal sugars, identified only mannose residues on SEAP expressed in the six insect cell lines. However, the oligosaccharide moiety of SEAP expressed in a Chinese hamster ovary cell line contained sialic acid. Therefore, when expressed in mammalian cells, the oligosaccharide present on SEAP is processed into complex oligosaccharide, but in insect cells it is of the high-mannose type. Studies with inhibitors of the initial oligosaccharide processing steps demonstrated that all six cell lines possessed glycosidase I/II and mannosidase I activity and that glycosylation was required for secretion.     

Cerebrin prohormone processing, distribution and action in Aplysia californica

The isolation, characterization, and bioactivity in the feeding circuitry of a novel neuropeptide in the Aplysia californica central nervous system are reported. The 17-residue amidated peptide, NGGTADALYNLPDLEKIamide, has been termed cerebrin due to its primary location in the cerebral ganglion. Liquid chromatographic purification guided by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry allowed the isolation of the peptide with purity adequate for Edman sequencing. The cerebrin cDNA has been characterized and encodes an 86 amino acid prohormone that predicts cerebrin and one additional peptide. Mapping using in situ hybridization and immunocytochemistry showed that cerebrin containing neuronal somata are localized almost exclusively in the cerebral ganglion, mostly in the F- and C-clusters. Both immunostaining and mass spectrometry demonstrated the presence of cerebrin in the neurohemal region of the upper labial nerve. In addition, immunoreactive processes were detected in the neuropil of all of the ganglia, including the buccal ganglia, and in some interganglionic connectives, including the cerebral-buccal connective. This suggests that cerebrin may also function as a local signaling molecule. Cerebrin has a profound effect on the feeding motor pattern elicited by the command-like neuron CBI-2, dramatically shortening the duration of the radula protraction in a concentration-dependent manner, mimicking the motor-pattern alterations observed in food induced arousal states. These findings suggest that cerebrin may contribute to food-induced arousal in the animal. Cerebrin-like immunoreactivity is also present in Lymnaea stagnalis suggesting that cerebrin-like peptides may be widespread throughout gastropoda.     

Long‐range seasonal migration in insects: mechanisms,evolutionary drivers and ecological consequences

Myriad tiny insect species take to the air to engage in windborne migration, but entomology also has its ‘charismatic megafauna’ of butterflies, large moths, dragonflies and locusts. The spectacular migrations of large day‐flying insects have long fascinated humankind, and since the advent of radar entomology much has been revealed about high‐altitude night‐time insect migrations. Over the last decade, there have been significant advances in insect migration research, which we review here. In particular, we highlight: (1) notable improvements in our understanding of lepidopteran navigation strategies, including the hitherto unsuspected capabilities of high‐altitude migrants to select favourable winds and orientate adaptively, (2) progress in unravelling the neuronal mechanisms underlying sun compass orientation and in identifying the genetic complex underpinning key traits associated with migration behaviour and performance in the monarch butterfly, and (3) improvements in our knowledge of the multifaceted interactions between disease agents and insect migrants, in terms of direct effects on migration success and pathogen spread, and indirect effects on the evolution of migratory systems. We conclude by highlighting the progress that can be made through inter‐phyla comparisons, and identify future research areas that will enhance our understanding of insect migration strategies within an eco‐evolutionary perspective.     

Suitability of California bay laurel and other species as hosts for the non‐native redbay ambrosia beetle and granulate ambrosia beetle

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