Process Optimization for Design of Duplex Universal Joint Fork using Unequal Thickness Flash

Chengliang Hu,Fan Zeng,Zhen Zhao,Zengjun Guo 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

To avoid defect formation, a two-step forging process for duplex fork was developed and optimized using an unequal thickness flash. The large cross-sectional difference between the different parts of the complex shape of the duplex fork made it difficult to forge. Crack defects formed during initial forging were observed and analyzed by finite element simulation, and the metal flow lines and velocity distributions on the main cross section were studied. A non-uniform velocity distribution with a large difference in the dangerous area and large amount of oxide scale most likely caused the crack defects. An optimized two-step forging process was developed, preupsetting was used to remove the oxide scale, and final forging using a die with an unequal flash gutter depth was used to obtain a reasonable velocity distribution. The effect of different process parameters on the optimized forging process was determined. The parameters included the pre-upsetting stroke, the friction factor, the workpiece mass, and the offset of the preform, and the results were used to improve the process stability. A duplex fork of acceptable quality and without any cracks was forged in successful trial production using the optimized process in the forging plant.

Comparative transcriptome analysis of wing discs from Bombyx mori and Bombyx mandarina

Feng Yongjie,Kumar Dhiraj,Hu Xiaolong,Zhang Yiling,Zhu Min,Xue Renyu,Cao Guangli,Gong Chengliang 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.2

The insect wing is developed from the wing imaginal disc which is designed from the embryonic ectoderm. To get insight into gene expression profiles in wing discs of Bombyx mori during metamorphosis, we compared the gene expression in the wing between B. mori and B. mandarina moth through RNA-seq. Out of total valid reads identified from the 5th day of 5th instar larvae of silkworm (L5), 7th day of pupae (P7), 1st day of moth (M1) and 1st day of wild silkworm moth (WM1), 20,092,004, 29,251,647, 24,654,695 and 19,753,089 reads were mapped to the mRNA reference sequences of silkworm, respectively. 9229, 7048, 9268 and 6701 differentially expressed genes (DEGs) were respectively recorded in P7 vs L5, M1 vs P7, M1 vs L5 and WM1 vs M1. Further, the peroxisome, ribosome, endocytosis and oxidative phosphorylation pathways were significantly regulated in the metamorphosis of the silkworm. Our study identified 16 orthologous genes with a positive selection from M1, which might be subjected to artificial selection in the domestication of B. mori and would play vital roles in the flight of B. mandarina.

Transient propagation of BmLV and dysregulation of gene expression in nontarget cells following BmLV infection

Feng Yongjie,Zhang Xing,Kumar Dhiraj,Kuang Sulan,Liu Bo,Hu Xiaolong,Zhu Min,Liang Zi,Cao Guangli,Xue Renyu,Gong Chengliang 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Bombyx mori latent virus (BmLV), a novel positive-strand RNA virus was first identified in the B. mori cultured BmN cell line. Whether the infectivity of BmLV to silkworm larvae and non-silkworm cells is connected with dysregulation of gene expression are not well understood. A complete sequence of BmLV genomic RNA was identified and revealed that a fragment with 495 nt in length was deleted from the RNA-dependent RNA poly merase (RdRp) gene in some BmLV genomic RNAs. Studies on the infectivity of BmLV to nontarget cells showed that BmLV can infect silkworm larvae, Spodoptera frugiperda Sf-9 and H1299 lung cancer cells with transient propagation. The dysregulation of gene expression of Sf-9 cells followed by BmLV infection was analyzed. Out of 743 differentially expressed genes (DEGs), 300 were upregulated and 443 were downregulated. Gene Ontology (GO) analysis indicated the DEGs were enriched into oxidoreductase activity for CH-NH 2 group donors, gluta mate biosynthetic process, response to stress and proteasome core complex. KEGG enrichment analysis showed that DEGs were mainly enriched into sulfur metabolism, RNA degradation, proteasome, pentose and glucuronate interconversions. Undesirable nutrients and temperature factors contributed to the propagation of BmLV in Sf-9 cells. Additionally, the Imd and RNAi pathways were activated by BmLV infection without stimulating Toll and JAK-STAT pathways. Therefore, it is suggested that BmLV is originated from plants, which can enter nontarget cells with transient propagation. The transient infection of BmLV may not only be regulated by Imd and RNAi immune pathways but also mediated by dysregulation of gene expression.

Study of gut bacterial diversity of Bombyx mandarina and Bombyx mori through 16S rRNA gene sequencing

Dhiraj Kumar,Zhenli Sun,Guangli Cao,Renyu Xue,Xiaolong Hu,Chengliang Gong 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

The wild silkworm B. mandarina is living in the natural environment has a strong stress resistance and adaptability after harsh natural selection. The indoor rearing or domestication of the wild silkworm under artificial custody for long period deteriorates stress resistance and ecological adaptability. Therefore, we aimed to investigate the effects of artificial domestication and evolutionary pressure on the gut bacterial diversity of B. mandarina and B. mori. The intestinal content of 6th day of fifth instar B. mandarina and B. mori larvae were analyzed by sequencing of the 16S rRNA gene through Illumina miseq sequencing technology. The outcome of the study revealed that abundance of predominant bacteria of phylum Firmicutes were respectively 81.40% and 81.85% in the late fifth instar silkworm larvae (6th day) of B. mandarina and B. mori. In Firmicutes, abundance of predominant bacterial genus Enterococcus in B. mandarina (69.73%) was comparatively higher than B. mori (48.99%). The genus Advenella belongs to phylum Proteobacteria was recorded only in B. mandarina (11.54%). The abundance of Unclassified_Peptostreptococcaceae, Methanobrevibacter, Ignatzschineria, Petrimonas and Proteiniphilum in B. mandarina were between 0.12 and 0.17%, nevertheless, these bacterial genera were not detected in B. mori. The abundance of genera Lactococcus, Bacillus and Pseudomonas in B. mori (17.73%, 5.02%, and 1.61%) were remarkably higher than B. mandarina (0.15%, 0.54% and 0.45%). These results indicated that substantial difference was observed between the intestinal bacteria of B. mori and B. mandarina population, and structure of the intestinal bacteria could be affected by the artificial domestication and evolutionary pressure.

Metatranscriptomic sequencing reveals there were abundant and diverse viruses in the midgut of diseased silkworm (Bombyx mori) with soft rot symptoms

Qiu Qunnan,Pan Jun,Kumar Dhiraj,Wei Shulin,Tong Xinyu,Zhu Min,Hu Xiaolong,Gong Chengliang 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.4

To date, six viruses belonging to genera Alphabaculovirus, Cypovirus, Iflavirus, Iteravirus, Bidensovirus and Maculavirus were harbored in the silkworm (Bombyx mori) and in the cultured BmN cells. Diseased silkworms with unknown etiology often create economic losses to the farmers. In the present investigation, the abundance and diversity of viruses in the midgut of diseased silkworms with soft rot symptoms were assessed by meta transcriptomic sequencing in order to screen the potential pathogenic virus of the silkworm, B. mori. After removal of undefined reads, clean reads were assembled, and the obtained 76 viral unigenes were annotated to 43 viruses. Among these viruses, the B. mori cypovirus, Pieris rapae virus, Nodaviridae sp., B. mori bidensovirus, Pseudomonas virus pf16, Pseudomonas phage Skulduggery, Klebsiella phage KPN U2874, Equid gamma herpesvirus 2, fowlpox virus and Xestia c-nigrum granulovirus were dominant virus species. These metatran scriptomic sequencing results provided new clues for screening and identifying novel pathogenic virus of the silkworm.

Cell proliferation can be modulated by receptor tyrosine kinase-like orphan receptor 2 in the silkworm, Bombyx mori

Yongjie Feng,Wei Liu,Dhiraj Kumar,Min Zhu,Renyu Xue,Guangli Cao,Xiaolong Hu,Chengliang Gong 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.4

The receptor tyrosine kinase-like orphan receptor 2 (Ror2) is involved in the Wnt/β-catenin signaling pathway which regulates cell proliferation, polarity, differentiation, migration, metabolism and survival. However, the function of Ror2 in the silkworm Bombyx mori is still undisclosed. In the present investigation, we have made an effort to clone the silkworm Ror2 gene (BmRor2). The sequence analysis showed that the open reading frame (ORF) was 1914 bp in size and encoded a protein with the conserved domains of Ror2 protein. The qRT-PCR results indicated that the BmRor2 gene expression level was the highest in the head among all identified tis sues on 3rd day of the fifth instar larvae. In the gonads of the different development stages, the BmRor2 gene expression level was highest on the 4th day of the fourth instar larvae. The immunofluorescence assay indicated that the BmRor2 protein was located at the cytomembrane. The effects of BmRor2 protein on the expression levels of genes related to TGF-β, Hippo, JAK-STAT and Notch signaling pathways were investigated by qRT-PCR. The expression levels of crumbs (crb), warts (wts), α-catenin (cat), four-jointed (fj), decapentaplegic (dpp), kibra ortholog (kibra), serrate (serr) and c-myc (myc) genes were down-regulated, whereas, suppressor of cytokine signaling 2 (socs 2) gene expression was up-regulated in the cultured BmN cells after the BmRor2 expression level was up-regulated. Further, cell proliferation was demoted and the size of cells was decreased when BmRor2 expression level was elevated. Our current finding recommended that BmRo2 can regulate TGF- β, Hippo, JAKSTAT, and Notch signaling pathways, and affect cell proliferation and size.