Abstract: Using silkworm (Bombyx mori, Dazao strain) as material, the fluorescent pigment of mulberry, silkworm blood, silk gland, cocoon shell, silkworm excrement, silkworm urine and moth urine were analyzed by using the technology of thin layer chromatography (TLC). The results indicated that there were 7 bands of fluorescent pigment from the extracts of green cocoon shell after TLC analysis. While, 2 bands in silkworm blood and its urine extracts, 4 bands in the silk gland extracts, as well as 5 bands in moth urine extracts were detected, but no band detection in the silkworm excrement extracts. The blue-violet fluorescent pigment which has the same Rf (0.35) was detected from the extracts of green cocoon shell, silk gland, silkworm urine, moth urine and mulberry after TLC analysis, but it cannot be found in silkworm blood and silkworm excrement. It was revealed that the blue-violet fluorescent pigment may be transferred directly from mulberry leaves, and then accumulated in the silk gland. Most of the pigment remained in the cocoon shell. And only a small amount of this kind of pigment was excreted through urine. There was also some yellow-green fluorescent pigment detected in the silkworm blood, silk gland and cocoon shell extracts, but it cannot be detected in both the mulberry and silkworm urine extracts. It was suggested that yellow-green fluorescent pigment synthesis pathway exist in the body of silkworm (Bombyx mori, Dazao strain).
Abstract: With the development of the PCR technology, especially the improvement of its reagent and a method of pebrine detection by PCR in infected Bombyx mori eggs was established.With the 16sRNA gene of Nosema bombycis as target sequence, the results of extraction of genomic DNA from purified microspores showed that 1.3×10-7µg DNA can be extracted from each spore. The sensitivity detection showed the detection limit of Nosema bombycis DNA was 3.25×10-2pg, i.e. 4 spores. (PCR system volume is 25µl). The method of total DNA extraction from pebrine infected silkworm eggs just before hatching was created. The result showed that extracting total DNA from silkworm eggs after the eggs had been treated with 30% KOH met the PCR detection requirements. The result of application study showed the spores in the pebrine infected egg just before hatching can sensitively be found with PCR. The result of a group of eggs just before hatching detection showed that the maximum PCR detection level was of a pebrine infected eggs just before hatching in 300 healthy eggs when the total DNA extraction had been purified with Agarose electrophoresis. The probability of identifying groups of one pebrine spore in infected eggs just before hatching mixed with 100 healthy ones was about 80%.
Abstract: Acetylcholinesterase (AChE, 2 EC 126.96.36.199), encoded by the ace gene, catalyzes the hydrolysis of the neurotransmitter acetylcholine to terminate nerve impulses at the postsynaptic membrane. In this study, AChE genes (Bm-ace1, Bm-ace2) were cloned from domesticated silkworm Bombyx mori (Dazao strain) through RT-PCR. Sequence analysis showed that the ORF of Bm-ace1 gene contained 2 025 bp nucleotides, encoding 683 amino acid residues. The predicted protein has a molecular weight (MW) of 76.96 kD and an isoelectric point (pI) of 6.36; The ORF of Bm-ace2 gene contained 1 917 bp nucleotides, encoding 638 AA’s. The predicted protein has a MW of 71.68 kD and a pI of 5.49. These two acetylcholinesterase genes both contain conserved motifs including a catalytic triad, a choline-binding site and an acyl picket. A clustering analysis showed that Bm-ace1 (ABY50088)shared highest similarity with Bmm-ace1 (ABM66370) from Chinese wild silkworm (B. mandarina), Bm-ace2 (ABY50089) shared highest similarity with Bm-ace2 (NP_001037366) from B. mori. Using semi-quantitative RT-PCR, expression analyses in insect tissues and in development period demonstrated that Bm-ace1and Bm-ace2 were expressed highly in head and fat bodies; Bm-ace1 and Bm-ace2 were expressed firstly higher, then lower and higher again from 1st instar to 5th instar stages. Bm-ace1 was expressed higher than that of Bm-ace2 in all the stages. This result will help understanding of the resistance mechanism of B. mori to organophosphosphorous insecticides.
Abstract: Serpins can block different steps in the activation cascade of prophenoloxidase (proPO) system, and play an important role in immunity of insect. In this paper, Haemolymph was collected from the 4th molting, newly moulted 5th instar and day-3 fifth instar larval challenged by lipopolysaccharide (LPS) or Bacillus thuringiensis, respectively. The results revealed that the transcriptional level of Bmserpin-6 in different developmental stages showed a trend of rise first, then fall. Bmserpin-6 of the 4th molting larva expressed highest at 6h post-infection with LPS and 3h post-infection with Bacillus thuringiensis. Bmserpin-6 of newly moulted 5th instar larva expressed highest at 9h post-infection with LPS and 6h post-infection with Bacillus thuringiensis. Bmserpin-6 of day-3 fifth instar larva expressed highest at 9h post-infection with Bacillus thuringiensis. Bmserpin-6 was all highly induced and highly expressed in haemolymph of larval at different developmental stages. But The time to arrive the highest transcriptional level was different. This is inferred that the Serpin gene may play an important role in immunity of Bombyx mori.
Abstract: To elucidate the physiological mechanism of mulberry fruit ripening in protein level, differential proteome expression of mulberry fruits was analyzed by using 2-DE and mass spectrometry in different ripening stages, green ripe stage(G), half ripe stage(R) and pan ripe stage(P). A mulberry cultivator, “Da10” was used as experimental material. The results showed that separation of proteins with 2-DE were significantly improved by using phenol/SDS buffer for protein extraction. 441, 222, 328 protein spots were detected respectively in ripening stage G, R and P. Among them, differential expression of 31 proteins was more than 2-fold and 6 proteins were stage-specific expression. 8 differential proteins were identified by MALDI-TOF/TOF MS analysis and database search, which were photosynthesis related proteins (ribulose bisphosphate carboxylase/oxygenase activase and ribulose bisphosphate carboxylase small subunit), stress related protein (18kD winter accumulating protein), glucose metabolism related protein (cell wall invertase）and so on, suggesting that these proteins may play the specific physiological role in mulberry fruits ripening.
Abstract: In order to investigate the differential expression of proteins related to pupation in silkworm, the fat body proteins were extracted from larvae of 5th day of 5th instar, un-pupated larvae and pupae of pupating day of multivoltine variety “da zao”. The optimized IPG-IEF/SDS-PAGE (2-DE) was used to analyze the differential expression of proteome in different developmental stage during pupation. The results showed that 66 proteins exhibited a more than two-fold differential expression, in which 43 proteins were down-regulated while 23 proteins were up-regulated. Additionally, 14 proteins with stage-specific expression characteristics were also observed. From 25 proteins with three-fold differential expression, 12 proteins were identified by MALDI-TOF/TOF MS, such as actin, calponin-like protein, NADH, beta-tubulin, receptor for activated protein kinase C, IMP cyclohydrolase, tropomyosin, antichymotrypsin precursor and 30K protein precursor etc. These results suggest that the differentially expressed proteins (enzymes) are related to the regulation of silkworm metamorphosis or sex differentiation, which provides a new experimental basis for better understanding the physiological functions and the mechanism of gene expression in silkworm fat body.
Abstract: Mulberry trees (Morus spp. Moraceae) are used for rearing the silkworm. Moraceae plants are characterized by the presence of latex, and mulberry trees exude latex when their stem, leaf or root were damaged. We found in the present study that mulberry latex contains very high concentrations of DNJ (0.63% wet weight, 4.5% dry weight), the DNJ content of latex varied with different part of tree and collecting time. The study also evaluated the antihyperglycemic effects of mulberry latex on streptozotocin induced diabetic mice. Diabetic mice were treated with mulberry latex or acarbose with food for 21 days. The results indicated that postprandial blood glucose and fasting-blood glucose level of mice were lowed, mulberry latex displayed a significant reduction ( P ≤ 0.05) in blood glucose. This finding suggested that mulberry latex have high value for herbal medicine as hypoglycemic function.
Abstract: With the Development of New Technologies in Silkworm Rearing though Sericulture Has now Emerged as a Main Profession and a Major Cash Crop for the Rural People of the India in Tropical Areas but in Temperate Belt Like Kashmir the Constraints Faced by the Sericulture Farmers/silkworm Rearers Are More and these Are Responsible for Yield Gaps which Have to Be Considered Seriously and Accordingly the Extension Services Need to Be Modulated and Implemented. Exploitable Yield Gaps in Border Areas Are Often Caused by Various Factors Including Physical, Biological, Socio-Economic and Institutional Constraints which Can Be Effectively Improved through Participatory and Holistic Approaches. Kashmir Is a Univoltine Area where for Generations only one Crop in Spring Season Is Taken between May and June. Spring (May – June, 2009) Data of Kandi Kupwara J&K India (Border Area) Revealed Varying Cocoon Yields from 7 to 13 Kgs Dry Cocoons per 100 DFLS with Cocoon Price Varying from Rs. 172-430 per Kg. these Facts and Figures Prove that these Silkworm Rearers by Realizing the Potential of Sericulture (a New Culture in a Border Area) Increased their Income Substantially from Rs. 720 to Rs.5590/100DFLS. it Was Also Found that Sericulture Productivity Can Be Further Increased by Planting Improved Varieties of Mulberry as it Has Been Observed that where, Very Good Quality Mulberry Leaf and Inputs Are Available, the Sericulture Productivity Is Reasonably Good. the Present Communication, Therefore, Discusses the Extension Strategies and New Technologies to Improve the Essential Knowledge and Skills to the Sericulture Farmers to Improve the Yield and Profitability of Sericulture.
Abstract: The cytochrome P450-dependent monooxygenases play an extremely important role in metabolic system involved in the catabolism and anabolism of xenobiotics and endogenous compounds. According to the predicted P450 sequences from the genome of Bombyx mori, a pair of primers was designed and a novel gene named CYP6AE22 was successfully cloned from the midgut mRNA of Bombyx mandarina by RT-PCR (GenBank accession number: FJ843077). Sequence analysis revealed that this gene contains a 1551 bp ORF, encoding a protein of 516 amino acids. The predicted molecular weight and isoelectric point of this protein was 60 kD and 9.0, respectively. The results of semi-quantitative RT-PCR showed that this gene was highly expressed in fat body and brain. And the expression level could be increased by induction with cypermethrin. Treatment with 5ng/uL cypermethrin could increase the expression level in midgut and fat body of the larvae of 1.5 fold and 2.5 fold, respectively. It is inferred that CYP6AE22 gene may be involved in detoxification of insecticide in Bombyx mandarina.