Gene expression and immunolocalization of chitin deacetylase BmCDA2 in silkworm / 生物工程学报

Deacetylation of chitin is closely related to insect development and metamorphosis. Chitin deacetylase (CDA) is a key enzyme in the process. However, to date, the CDAs of Bombyx mori (BmCDAs), which is a model Lepidopteran insect, were not well studied. In order to better understand the role of BmCDAs in the metamorphosis and development of silkworm, the BmCDA2 which is highly expressed in epidermis was selected to study by bioinformatics methods, protein expression purification and immunofluorescence localization. The results showed that the two mRNA splicing forms of BmCDA2, namely BmCDA2a and BmCDA2b, were highly expressed in the larval and pupal epidermis, respectively. Both genes had chitin deacetylase catalytic domain, chitin binding domain and low density lipoprotein receptor domain. Western blot showed that the BmCDA2 protein was mainly expressed in the epidermis. Moreover, fluorescence immunolocalization showed that BmCDA2 protein gradually increased and accumulated with the formation of larval new epidermis, suggesting that BmCDA2 may be involved in the formation or assembly of larval new epidermis. The results increased our understandings to the biological functions of BmCDAs, and may facilitate the CDA study of other insects.

Analyzing the evolution of insect TMED gene and the expression pattern of silkworm TMED gene / 生物工程学报

Transmembrane emp24 domain (TMED) gene is closely related to immune response, signal transduction, growth and disease development in mammals. However, only the Drosophila TMED gene has been reported on insects. We identified the TMED family genes of silkworm, Tribolium castaneum, tobacco moth and Italian bee from their genomes, and found that the TMED family gene composition patterns of one α-class, one β-class, one δ-class and several γ-classes arose in the common ancestor of pre-divergent Hymenoptera insects, while the composition of Drosophila TMED family members has evolved in a unique pattern. Insect TMED family γ-class genes have evolved rapidly, diverging into three separate subclasses, TMED6-like, TMED5-like and TMED3-like. The TMED5-like gene was lost in Hymenoptera, duplicated in the ancestors of Lepidoptera and duplicated in Drosophila. Insect TMED protein not only has typical structural characteristics of TMED, but also has obvious signal peptide. There are seven TMED genes in silkworm, distributed in six chromosomes. One of seven is single exon and others are multi-exons. The complete open reading frame (ORF) sequences of seven TMED genes of silkworm were cloned from larval tissues and registered in GenBank database. BmTMED1, BmTMED2 and BmTMED6 were expressed in all stages and tissues of the silkworm, and all genes were expressed in the 4th and 5th instar and silk gland of the silkworm. The present study revealed the composition pattern of TMED family members, their γ class differentiation and their evolutionary history, providing a basis for further studies on TMED genes in silkworm and other insects.

Genome-wide identification of the BmAKR gene family in the silkworm (Bombyx mori) and their expression analysis in diapause eggs and nondiapause eggs / 生物工程学报

The aldo-keto reductase super family (AKRs) has a wide range of substrate specificity. However, the systematic identification of insect AKR gene family members has not been reported. In this study, bioinformatics methods were used to predict the phylogenetic evolution, physical and chemical properties, chromosome location, conserved motifs, and gene structure of AKR family members in Bombyx mori (BmAKR). Transcriptome data or quantitative real time polymerase chain reaction (qRT-PCR) were used to analyze the expression level of BmAKR genes during different organizational periods and silkworm eggs in different developmental states. Moreover, Western blotting was used to detect the expression level of the BmAKR in silkworm eggs. The results showed that 11 BmAKR genes were identified. These genes were distributed on 4 chromosomes of the silkworm genome, all of which had the (α/β) 8-barrel motif, and their physical and chemical characteristics were relatively similar. Phylogenetic analysis showed that the BmAKR genes could be divided into 2 subgroups (AKR1 and AKR2). Transcriptome data analysis showed that the expression of BmAKR genes were quite different in different tissues and periods. Moreover, the expression analysis of BmAKR genes in silkworm eggs showed that some genes were expressed significantly higher in nondiapause eggs than in diapause eggs; but another gene, BmAKR1-1, was expressed significantly higher in diapause eggs than in nondiapause eggs. The detection of protein level found that the difference trend of BmAKR1-1 in diapause eggs and non-diapause eggs was consistent with the results of qRT-PCR. In conclusion, BmAKR1-1 was screened out as candidates through the identification and analysis of the BmAKR genes in silkworm, which may regulate silkworm egg development is worthy of further investigation.

Development of a CRISPR/Cpf1 gene editing system in silkworm Bombyx mori / 生物工程学报

The CRISPR/Cas9 gene editing system has been widely used in basic research, gene therapy and genetic engineering due to its high efficiency, fast speed and convenience. Meanwhile, the discovery of novel CRISPR/Cas systems in the microbial community also accelerated the emergence of novel gene editing tools. CRISPR/Cpf1 is the second type (V type) CRISPR system that can edit mammalian genome. Compared with the CRISPR/Cas9, CRISPR/Cpf1 can use 5'T-PAM rich region to increase the genome coverage, and has many advantages, such as sticky end of cleavage site and less homologous recombination repair. Here we constructed three CRISPR/Cpf1 (AsCpf1, FnCpf1 and LbCpf1) expression vectors in silkworm cells. We selected a highly conserved BmHSP60 gene and an ATPase family BmATAD3A gene to design the target gRNA, and constructed gHSP60-266 and gATAD3A-346 knockout vectors. The efficiency for editing the target genes BmATAD3A and BmHSP60 by AsCpf1, FnCpf1 and LbCpf1 were analyzed by T7E1 analysis and T-clone sequencing. Moreover, the effects of target gene knockout by different gene editing systems on the protein translation of BmHSP60 and BmATAD3A were analyzed by Western blotting. We demonstrate the CRISPR/Cpf1 gene editing system developed in this study could effectively edit the silkworm genome, thus providing a novel method for silkworm gene function research, genetic engineering and genetic breeding.

Verificação da interferência do solvente propilenoglicol sobre o efeito da própolis na produção de lagartas de Bombyx mori L. (Lepidoptera: bombicidae) comparado ao extrato alcoólico de própolis / Interference of propyleneglycol solvent on the effect of propolis in the production of silkworm Bombyx mori L. (Lepidoptera: bombicidae) compared to propolis alcoholic extract / Verificación de la interferencia del solvente propilenoglicol sobre el efecto de propóleos en la producción de gusano de seda Bombyx mori L. (lepidoptera: bombicidae) comparado al extracto alcohólico de propóleos

Este experimento foi realizado no Laboratório de Sericicultura, no Campus Sede da Universidade Paranaense (UNIPAR) de Umuarama, no período de fevereiro a outubro de 2011, com o objetivo de verificar o efeito da própolis em diferentes dosagens na alimentação durante o desenvolvimento biológico do bicho-da-seda (Bombxy mori L.). O método empregado na parte experimental foi a pulverização do extrato glicólico de própolis, diluído em 500mL de água destilada nas folhas de amoreira, nas seguintes dosagens, água-controle, 25mL, 30mL, 35mL e 40mL compondo os tratamentos: controle, T1 , T2 , T3 e T4 respectivamente. As folhas de amoreira foram fornecidas cinco vezes ao dia, durante o manejo alimentar. Verificou-se, pelos resultados obtidos, que as diferentes dosagens de própolis utilizadas não interferiram no ganho de peso das lagartas, no peso dos casulos verdes, no peso da casca sérica e crisálidas, quando comparado ao tratamento controle, mas quando se compara o Controle e T4 do ensaio da primavera, respectivamente, para os teores de seda bruto e líquido, há resultados significativos. Portanto, verificou-se que o extrato glicólico de própolis, em dosagens de 40mL, pode prejudicar o teor líquido de seda em uma produção de casulos, trazendo resultados pouco apreciados dentro da sericicultura...

This experiment was performed at the Laboratory of Sericulture, at the main campus of University Paranaense (UNIPAR), in the city of Umuarama, from February to October 2011, in order to verify the effect of different doses of propolis in feeding during the biological development of silkworm (Bombyx mori L.). The method used in the experiment was the spraying of propolis glycolic extract dissolved in 500-mL distilled water on the mulberry leaves in the following water- -control dosages: 25mL, 30mL, 35mL and 40mL related to the treatment controls T1, T2, T3 and T4, respectively. Mulberry leaves were provided five times a day for feeding management. The results obtained showed that the different dosages of propolis used did not affect the weight gain of the larvae, the weight of green cocoons, shells and pupae when compared to the control treatment. However, when comparing the control and T4 from the Spring assay, respectively, to the levels of crude and net silk, significant results were noted. Thus, it can be concluded that propolis glycolic extract in 40-ml dosages may impair the net silk content in a cocoon production, presenting negative results in sericulture...

: Este experimento se llevó a cabo en el Laboratorio de Sericultura, Campus Sede de la Universidad Paranaense (UNIPAR) de Umuarama, en el período de febrero a octubre de 2011, con el fin de verificar el efecto de propóleos en diferentes concentraciones en la alimentación durante el desarrollo biológico del gusano de seda (Bombyx mori L.). El método utilizado en el experimento fue la pulverización de extracto glicólico de propóleos, disuelto en 500 ml de agua destilada en las hojas de morera, en las siguientes dosis, agua control, 25 mL, 30mL, 35 mL, y 40 mL componiendo los tratamientos: control T1 , T2 , T3 e T4 respectivamente. A las hojas de morera se les han dado cinco veces al día, durante el manejo alimentar. Se verificó, por los resultados obtenidos, que las diferentes dosis de propóleos utilizados no afectaron en la ganancia de peso de los gusanos, en el peso de los capullos verdes, en el peso de la cáscara sérica y crisálidas, en comparación con el tratamiento de control, pero cuando se compara el Control y T4 del ensayo de la primavera, respectivamente, para los niveles de seda cruda y líquida, hay resultados significativos. Por lo tanto, se encontró que el extracto glicólico de propóleos, en dosis de 40 mL, puede perjudicar la concentración líquida de seda en una producción de capullos, trayendo resultados poco apreciados dentro de la sericultura...

Immune enhancement activities of silk lutein extract from Bombyx mori cocoons

BACKGROUND: Declining immune function poses an important clinical challenge worldwide and supplementation with natural products that possessing immune enhancing properties is a promising approach for preventing or delaying immune function decline. Cocoons from yellow silkworms are a significant source of lutein, and this unexplored silk extract could be a viable alternative source for dietary lutein. This study assessed immunomodulatory activities of the silk lutein extract. Female BALB/c mice orally received lutein, either as silk or marigold extracts (10 or 20 mg/kg daily), or vehicle only (1% tween 80 in PBS pH 7.4) for 4 weeks. Natural killer (NK) cell activity, specific antibody production, lymphocyte subpopulations, mitogen-induced lymphocyte proliferation, and cytokine production were examined. RESULTS: Silk lutein extract increased NK cell activity, and the effect was dose-related whereas marigold lutein extract was ineffective. Silk lutein extract dose-dependently enhanced antibody production in pre-immunized mice but marigold lutein extract had no effect. Feeding with silk lutein extract increased the populations of CD3+ and CD4 + CD3 + cells. Silk lutein extract also stimulated concanavalin A- and lipopolysaccharide-induced proliferations of T and B lymphocytes, respectively. Moreover, silk lutein extract increased IL-2 and IFN-γ production while the effect of marigold lutein extract was undetectable. CONCLUSIONS: Together, silk lutein extract enhanced both innate and adaptive immune functions. This preparation may prove to be an effective supplement for strengthened immunity.

Protective effect of silk lutein on ultraviolet B-irradiated human keratinocytes

Carotenoids are efficient antioxidants that are of great importance for human health. Lutein and zeaxanthin are carotinoids present in high concentrations in the human retina which are involved in the photoprotection of the human eye. Lutein may also protect the skin from ultraviolet (UV)-induced damage. The present study investigated the protective effect of lutein extracted from yellow silk cocoons of Bombyx mori on human keratinocytes against UVB irradiation. A human keratinocyte cell line and primary human keratinocytes were used to investigate the UVB protection effects of silk lutein and plant lutein. Silk lutein showed no cytotoxicity to keratinocytes. Treatment with silk lutein prior to UVB irradiation enhanced cell viability and cell proliferation, and reduced cell apoptosis. The protective effects of silk lutein may be superior to those of plant lutein. Silk lutein may have a benefit for protection of keratinocytes against UVB-irradiation.

Fuel mobilization for energy metabolism in the silkmoth, Bombyx mori, during reproductive processes.

Flight muscles of male moth, B. mori seem to utilize carbohydrate preferentially as a source of energy for all its acrobatic movements during the search for female moth. Depletion of triacylglycerol from flight muscles without affecting its level from fat body suggests that this lipid fraction serves as a source of energy in flight muscles during insemination processes. Significant depletion of triacylglycerol and glycogen from flight muscles of female moth after egg laying indicates that they are used to meet the energy requirement of female during oviposition activity. Depletion of proteins from flight muscles of male and female insects suggest that these proteins are transported to the accessory reproductive glands to meet their protein demand.