anjiang tan

Genetically engineered silkworms have been widely used to obtain silk with modified characteristics especially by introducing spider silk genes. However, these attempts are still challenging due to limitations in transformation strategies and difficulties in integration of the large DNA fragments. Here, we describe three different transformation strategies in genetically engineered silkworms, including transcription-activator-like effector nuclease (TALEN)-mediated fibroin light chain (FibL) fusion (BmFibL-F), TALEN-mediated FibH replacement (BmFibH-R), and transposon-mediated genetic transformation with the silk gland-specific fibroin heavy chain (FibH) promoter (BmFibH-T)...

BACKGROUND: Intestinal barrier dysfunction caused by the disrupted balance of group 3 innate lymphoid cells (ILC3)/group 1 innate lymphoid cells (ILC1) is a significant feature in the pathogenesis of inflammatory bowel disease (IBD). Activation of aryl hydrocarbon receptor (AhR) signaling contributes to the maintenance of ILC3/ILC1 balance. Wogonin, a natural flavonoid from Scutellaria baicalensis Georgi, can repair intestinal mucosal damage of IBD. However, it remains unclear if wogonin can exert a therapeutic effect by activating the AhR pathway to regulate the plasticity of ILC3/ILC1...

Reproduction, a fundamental feature of all known life, closely correlates with energy homeostasis. The control of synthesizing and mobilizing lipids are dynamic and well-organized processes to distribute lipid resources across tissues or generations. However, how lipid homeostasis is precisely coordinated during insect reproductive development is poorly understood. Here we describe the relations between energy metabolism and reproduction in the silkworm, Bombyx mori, a lepidopteran model insect, by using CRISPR/Cas9-mediated mutation analysis and comprehensively functional investigation on two major lipid lipases of Brummer (BmBmm) and hormone-sensitive lipase (BmHsl), and the sterol regulatory element binding protein (BmSrebp)...

A detailed and accurate combustion reaction mechanism is crucial for understanding the nature of fuel combustion. In this work, a theoretical study of reaction HCCO+HO2 using M06-2X/6-311++G(d,p) for geometry optimization and combined methods based on spin-unrestricted CCSD(T)/CBS level of theory with basis set extrapolation from MP2/aug-cc-pVnZ (n = T and Q) for energy calculations were performed. The temperature- and pressure-dependent rate coefficients at 300-2000 K and 0.01-100 atm, suitable for combustion conditions, were derived using the Rice-Ramsberger-Kassel-Marcus/Master-Equation approach...

The diversity of cell types in the brain and how these change during different developmental stages, remains largely unknown. The life cycle of insects is short and goes through 4 distinct stages including embryonic, larval, pupal, and adult stages. During postembryonic life, the larval brain transforms into a mature adult version after metamorphosis. The silkworm, Bombyx mori, is a lepidopteran model insect. Here, we characterized the brain cell repertoire of larval and adult B. mori by obtaining 50 708 single-cell transcriptomes...

Plants produce various pigments that not only appear as attractive colors but also provide valuable resources in applications in daily life and scientific research. Biosynthesis pathways for these natural plant pigments are well studied, and most have multiple enzymes that vary among plant species. However, adapting these pathways to animals remains a challenge. Here, we describe successful biosynthesis of betalains, water-soluble pigments found only in a single plant order, Caryophyllales, in transgenic silkworms by coexpressing three betalain synthesis genes, cytochrome P450 enzyme CYP76AD1 , DOPA 4,5-dioxygenase, and betanidin 5-O-glucosyltransferase ...

The well-known morphogen Hedgehog (Hh) is indispensable for embryo patterning and organ development from invertebrates to vertebrates. The role of Hh signaling pathway has been extensively investigated in the model organism Drosophila melanogaster, whereas its biological functions are still poorly understood in non-drosophilid insects. In the current study, we describe comprehensive investigation of Hh biological roles in the model lepidopteran insect Bombyx mori by using both CRISPR/Cas9-mediated gene ablation and Gal4/UAS-mediated ectopic expression...

Efficient printing frequency is critical for thermal bubble inkjet printing, while the difficulty lies in the structural design and material selection of the heating resistors. In this paper, a TaN film was used as the main material of the heating resistors, and two TaN films were placed in parallel to form the chopsticks-shaped structure. The heating time was divided into two sections, in which 0-0.1 μs was the preheating and 1.2-1.8 μs was the primary heating. At 1.8 μs, the maximum temperature of the Si3 N4 film could reach about 1100 °C...

Periodic post-embryonic changes in insects, including growth, development and metamorphosis, are strictly controlled by many compounds, including steroid hormones. The biosynthesis and clearance of 20-hydroxyecdysone (20E), the major active form of the insect steroid hormone ecdysone, result in titer fluctuations that help control insect development. The inactivation of 20E in the silkworm Bombyx mori is highly tissue-specific, with CYP18A1 and ecdysone oxidase controlling 20E inactivation specifically in the mid-silk gland and midgut, respectively...

Recent identification of a Piwi-interacting RNA (piRNA)-initiated sex determination cascade in the silkworm, Bombyx mori, provides novel insights into high diversity of insect sex determination pathways. In this system, the W-chromosome-derived Fem piRNA is the primary sex determination signal. A CCCH-type zinc finger gene Masculinizer (Masc), which is targeted by Fem piRNA-PIWI complex in female animals, is indispensable for male-specific splicing of B. mori doublesex (Bmdsx). Although many genes involved in this cascade have been identified, the regulatory mechanisms of silkworm sex determination remain to be elucidated...

Two paralogous genes, teashirt (tsh) and tiptop (tio), encode zinc-finger transcription factors and play important roles in insect growth and development. In the fruit fly, Drosophila melanogaster, tsh promotes trunk segmental identities and contributes to the patterning of other tissues during the embryonic stage. During the adult stage, tsh contributes to the specification and patterning of appendages, including the leg, wing and eye. While tio acts redundantly with tsh, flies lacking tio function are viable without deleterious phenotypes...

The functional information on heat-shock proteins (Hsp) and heat-shock promoters from an important agricultural insect pest, Spodoptera frugiperda, is still lacking. We conducted a genome-wide identification of Hsp genes and identified a total of 21 genes belonging to four major insect Hsp families (small heat-shock proteins, Hsp60, Hsp70, and Hsp90) in S. frugiperda. Expression of most of S. frugiperda (SfHsp) genes could be detected in Sf9 cells, embryos and larval tissues of S. frugiperda. The heat-inducible activity of heat-shock promoters from several SfHsp genes was tested in Sf9 cells and embryos...

The dedicator of cytokinesis 5 (DOCK5) is associated with obesity. However, the mechanism by which DOCK5 contributes to obesity remains completely unknown. Here, we show that hepatic DOCK5 expression significantly decreases at a state of insulin resistance (IR). Deletion of DOCK5 in mice reduces energy expenditure, promotes obesity, augments IR, dysregulates glucose metabolism, and activates the mTOR (Raptor)/S6K1 pathway under a high-fat diet (HFD). The overexpression of DOCK5 in hepatocytes inhibits gluconeogenic gene expression and increases the level of insulin receptor (InsR) and Akt phosphorylation...

The spermatogenesis of animal is essential for the reproduction and a very large number of genes participate in this procession. The Maelstrom (Mael) is identified essential for spermatogenesis in both Drosophila and mouse, though the mechanisms appear to differ. It was initially found that Mael gene is necessary for axis specification of oocytes in Drosophila, and recent studies suggested that Mael participates in the piRNA pathway. In this study, we obtained Bombyx mori Mael mutants by using a binary transgenic CRISPR/Cas9 system and analyzed the function of Mael in B...

Sex separation methods are critical for genetic sexing systems in commercial insect production and sterile insect techniques. Integration of selectable marker genes into a sex chromosome is particularly useful in insects with a heterogametic sex determination system. Here, we describe targeted gene integration of fluorescent marker expression cassettes into a randomly amplified polymorphic DNA (RAPD) marker region in the W chromosome of the lepidopteran model insect Bombyx mori using transcriptional activator-like effector nuclease (TALEN)-mediated genome editing...

Spider silk is one of the best natural fibers and has superior mechanical properties. However, the large-scale harvesting of spider silk by rearing spiders is not feasible, due to their territorial and cannibalistic behaviors. The silkworm, Bombyx mori , has been the most well known silk producer for thousands of years and has been considered an ideal bioreactor for producing exogenous proteins, including spider silk. Previous attempts using transposon-mediated transgenic silkworms to produce spider silk could not achieve efficient yields, due to variable promoter activities and endogenous silk fibroin protein expression...

Sex determination is a hierarchically-regulated process with high diversity in different organisms including insects. The W chromosome-derived Fem piRNA has been identified as the primary sex determination factor in the lepidopteran insect, Bombyx mori, revealing a distinctive piRNA-mediated sex determination pathway. However, the comprehensive mechanism of silkworm sex determination is still poorly understood. We show here that the silkworm PIWI protein BmSiwi, but not BmAgo3, is essential for silkworm sex determination...

The yellow gene family has been identified in several model insects, but yellow genes were poorly identified in non-model insects and the functions of yellow genes are largely unknown. In this study, we identified seven yellow genes in an important agricultural pest Agrotis ipsilon. Each gene encodes a protein containing a major royal jelly domain. Phylogenetic analysis defined these genes as yellow-y, -b, -b2, -c, -d, -e, and -h, respectively. The A. ipsilon yellow genes yellow-b, -b2, and -c were stably expressed in all developmental stages and tissues analyzed, whereas the other four yellow genes had unique expression patterns, suggesting distinct physiological roles of each gene...

MicroRNAs (miRNA) regulate multiple physiological processes including development and metamorphosis in insects. In the current study, we demonstrate that a conserved invertebrate miRNA-14 (miR-14) plays an important role in ecdysteroid regulated development in the silkworm Bombyx mori, a lepidopteran model insect. Ubiquitous transgenic overexpression of miR-14 using the GAL4/UAS system resulted in delayed silkworm larval development and smaller body size of larva and pupa with decrease in ecdysteriod titers...

Forkhead box O (FOXO) functions as the terminal transcription factor of the insulin signaling pathway and regulates multiple physiological processes in many organisms, including lifespan in insects. However, how FOXO interacts with hormone signaling to modulate insect growth and development is largely unknown. Here, using the transgene-based CRISPR/Cas9 system, we generated and characterized mutants of the silkworm Bombyx mori FOXO ( BmFOXO ) to elucidate its physiological functions during development of this lepidopteran insect...