Upf2-Mediated Nonsense-Mediated Degradation Pathway Involved in Genetic Compensation of Knockout Mutant Silkworm ().

Genetic mutations leading to premature termination codons are known to have detrimental effects. Using the Lepidoptera model insect, the silkworm (), we explored the genetic compensatory response triggered by mutations with premature termination codons. Additionally, we delved into the molecular mechanisms associated with the nonsense-mediated mRNA degradation pathway.

Exorista sorbillans (Diptera: Tachinidae) parasitism shortens host larvae growth duration by regulating ecdysone and juvenile hormone titers in Bombyx mori (Lepidoptera: Bombycidae).

The tachinid fly, Exorista sorbillans, is a notorious ovolarviparous endoparasitoid of the silkworm, Bombyx mori, causing severe damage to silkworm cocoon industry. Silkworm larvae show typically precocious wandering behavior after being parasitized by E. sorbillans; however, the underlying molecular mechanism remains unexplored.

mA-dependent mevalonate kinase in juvenile hormone synthesis pathway regulates the diapause process of bivoltine silkworm (Bombyx mori).

Background: Research has shown that epigenetic modification are involved the regulation of diapause in bivoltine silkworms (Bombyx mori), but it remains unclear how epigenetic modification in response to environmental signals precisely to regulate the diapause processing of bivoltine B. mori.

Methods And Results: In this study, the diapause terminated eggs of bivoltine B.

Bombyx mori miR-2845 represses the expression of fibroin light chain gene both in vitro and in vivo.

To study the regulatory function of Bombyx mori (B. mori) miRNAs (bmo-miR) on the expression of fibroin light chain gene (BmFib-L), the 3'UTR of BmFib-L mRNA was used as the target for online prediction of miRNAs from miRBase using RNAhybrid Software, and miR-2845 was screened out. First, the expression profiles of miR-2845 and BmFib-L in larvae of the 5th instar were analyzed by Real-time quantitative PCR (RT-qPCR).

A 14-amino acids deletion in BmShadow results to non-moult on the 2nd instar in the bivoltine silkworm, Bombyx mori.

The Bombyx mori Shadow gene (BmShadow) belongs to the superfamily of cytochrome P450 genes. To elucidate the function of the BmShadow gene and its association with diapause, we employed the CRISPR/Cas9 system to knock out the BmShadow gene in the bivoltine strain Qiufeng. The mutant (BmShadow) was obtained in G, exhibiting a 42-base deletion corresponded exactly to the amino acids regions from positions 155 to 168.

Cordyceps cicadae polysaccharides inhibit human cervical cancer hela cells proliferation via apoptosis and cell cycle arrest.

The present study presented the extraction and purification of polysaccharides from artificially cultured Cordyceps cicadae and wild Cordyceps cicadae by pre-soaking ultrasonic water extraction. The effects of different concentrations of polysaccharides on proliferation and cytotoxicity of Hela cells were detected by MTT and LDH methods. The results showed that the proliferation of Hela cells was inhibited by polysaccharides treatment (25 μg/mL-1600 μg/mL).

[Advances in m A modification and its regulation of viral replication].

N -methyladenosine (m A) is a prevalent modification of RNA in eukaryotes and plays an important role in the process of mRNA translocation, stabilization and translation. m A exerts different influences on the viral replication cycle, and both viral replication and host immune response to the virus are affected by m A. In this review, we summarize recent studies on the mechanism of m A modification and its effects on viral replication and host immune response, in order to provide a reference for epigenetic regulation in the viral life cycle.

Transcriptome sequencing reveals potential mechanisms of diapause preparation in bivoltine silkworm Bombyx mori (Lepidoptera: Bombycidae).

In the bivoltine strain of the silkworm, Bombyx mori, embryonic diapause is induced transgenerationally as a maternal effect. Progeny diapause ability is determined by the environmental condition such as temperature and lightness that mothers experience during their own embryonic development. Diapause preparation is a crucial phase of this process; diapause-destined individuals undergo a series of preparatory events before the entry into developmental arrest.

bmo-miR-0001 and bmo-miR-0015 down-regulate expression of Bombyx mori fibroin light chain gene in vitro.

Based on bioinformatic analysis, we selected two novel microRNAs (miRNAs), bmo-miR-0001 and bmo-miR-0015, from high-throughput sequencing of the Bombyx mori larval posterior silk gland (PSG). Firstly, we examined the expression of bmo-miR-0001 and bmo-miR 12 different tissues of the 5th instar Day-3 larvae of the silkworm. The results showed that the expression levels of both bmo-miR-0001 and bmo-miR-0015 were obviously higher in the PSG than in other tissues, implying there is a spatio-temporal condition for bmo-miR-0001 and bmo-miR-0015 to regulate the expression of BmFib-L.

Overview of research on Bombyx mori microRNA.

MicroRNAs (miRNAs) constitute some of the most significant regulatory factors involved at the post-transcriptional level after gene expression, contributing to the modulation of a large number of physiological processes such as development, metabolism, and disease occurrence. This review comprehensively and retrospectively explores the literature investigating silkworm, Bombyx mori L. (Lepidoptera: Bombicidae), miRNAs published to date, including discovery, identification, expression profiling analysis, target gene prediction, and the functional analysis of both miRNAs and their targets.

Differentially expressed genes in the ovary of the sixth day of pupal "Ming" lethal egg mutant of silkworm, Bombyx mori.

The "Ming" lethal egg mutant (l-em) is a vitelline membrane mutant in silkworm, Bombyx mori. The eggs laid by the l-em mutant lose water, ultimately causing death within an hour. Previous studies have shown that the deletion of BmEP80 is responsible for the l-em mutation in silkworm, B.

The regulation of silkworm fibroin L chain production by miRNA-965 and miRNA-1926 in insect cells.

MicroRNAs (miRNAs) are an abundant class of approximately 22-nucleotide (nt)-short noncoding RNA molecules present in the genomes of all multicellular organisms that act through base pairing to partially complementary sequences of the 3'untranslated region (UTR) of targeted mRNAs. Using bioinformatic approach, we found that the 3'UTR of the Fibroin L chain (Fib-L) mRNA matches perfectly the nucleotides 2-8 at the 5' end of the miRNA-965 and miRNA-1926. These two miRNAs might act as regulators of Fib-L gene expression at the post-transcriptional level.

Proteomic analysis of the phenotype of the scaleless wings mutant in the silkworm, Bombyx mori.

A scaleless wing mutant of silkworm, Bombyx mori, has much fewer scales than wild type (WT). The scaleless phenotype was associated with tracheal system developmental deficiency and excessive apoptosis of scale cells. In this study, the wing discs proteins of WT and scaleless during pupation were studied using 2-DE and mass spectrometry.

Construction of baculovirus expression vector of miRNAs and its expression in insect cells.

MicroRNAs (miRNAs) are endogenous small non-protein coding RNAs that play important regulatory roles in animals and plants by binding to target transcripts for cleavage or translational repression. The miR-9a is very conservative in animals from flies to humans. Studies indicated that miR-9a is involved in the regulation of neurogenesis in animals.

Differential expression of microRNA-2b with potential target coding P25 in the fifth instar larvae posterior silk gland of the silkworm.

MicroRNAs (miRNAs) are a class of non-protein coding small RNAs that regulate a gene expression at the post-transcriptional level. Using in silico screening, we found that the 3'-untranslated regions of the P25 gene mRNA are perfectly complementary to nucleotides 2-8 at the 5' end of the miRNA-2b (miR-2b). The expression of miR-2b and the P25 gene in posterior silk gland of the fifth instar larval silkworm was investigated using real-time PCR detection method.

Recombinant canine parvovirus-like particles express foreign epitopes in silkworm pupae.

The capsid structural protein VP2 of canine parvovirus (CPV) can self-assemble into highly organized virus-like particles (VLPs) and retain major immunoreactivity. In this study, different recombinant baculoviruses that expressed varying fusion proteins of the CPV VP2 protein with the T cell determinant and/or the linear virus-neutralizing epitope of rabies virus (RV) were generated. Infection with these baculoviruses changed BmN cell morphology and inhibited their proliferation as well as damaged silkworms and pupae.

Construction and detection of expression vectors of microRNA-9a in BmN cells.

MicroRNAs (miRNAs) are small endogenous RNAs molecules, approximately 21-23 nucleotides in length, which regulate gene expression by base-pairing with 3' untranslated regions (UTRs) of target mRNAs. However, the functions of only a few miRNAs in organisms are known. Recently, the expression vector of artificial miRNA has become a promising tool for gene function studies.

Genomic analysis of silkworm microRNA promoters and clusters.

MicroRNAs (miRNAs) are endogenous single-stranded RNAs of 18-22 nt in length, which can regulate the complementary mRNAs at the post-transcriptional level by cleavage or repression of translation of the target mRNAs. Studies have shown that the majority of animal miRNAs are transcribed from independent transcription units, and someare transcribed together with their host genes. However, the nature of the primary transcript of intergenic miRNAs remains unknown.

Biological functions of microRNAs.

The small regulatory non-coding RNA molecules, known as microRNAs (miRNAs), have been recognized as potential regulator of gene expression and modulate the gene function at the post-transcriptional level. It is now clear that miRNA biogenesis and function are related to the molecular mechanisms of various clinical diseases, which can potentially regulate every aspect of cellular activity, including differentiation and development, metabolism, proliferation, apoptotic cell death viral infection and tumorgenesis. Here, we review recent work and provide insight into the diverse roles of miRNAs.

The discovery approaches and detection methods of microRNAs.

MicroRNAs (miRNAs) are small, highly conserved, non-coding RNAs that regulate gene expression of target mRNAs through cleavage or translational inhibition. Computer-based approaches for miRNA gene identification are being considered as indispensable in miRNAs research. Similarly, experimental approaches for detection of miRNAs are crucial to the testing and validating of computational algorithms.

Biological functions of microRNAs: a review.

MicroRNAs (miRNAs) are a recently discovered family of endogenous, noncoding RNA molecules approximately 22 nt in length. miRNAs modulate gene expression post-transcriptionally by binding to complementary sequences in the coding or 3' untranslated region of target messenger RNAs (mRNAs). It is now clear that the biogenesis and function of miRNAs are related to the molecular mechanisms of various clinical diseases, and that they can potentially regulate every aspect of cellular activity, including differentiation and development, metabolism, proliferation, apoptotic cell death, viral infection and tumorgenesis.

Computational identification and characteristics of novel microRNAs from the silkworm (Bombyx mori L.).

MicroRNAs (miRNAs) are a class of non-protein coding small RNAs that regulate expression of genes at post-transcriptional levels. Increasing evidence has shown that miRNAs play multiple roles in biological processes, including development, cell proliferation and apoptosis. Based on the conservation of miRNAs sequence, using a computational homology search based on genomic survey sequence analysis, a total of 16 novel miRNAs were identified and characteristics such as family and evolutionary conservation have been described.

Molecular cloning and characterization of hatching enzyme-like gene in the silkworm, Bombyx mori.

Hatching is the important process for the life of the metazoan, in which hatching enzyme (HE) plays a key role. In this paper, we cloned the full-length sequence of hatching enzyme-like cDNA from bluish-silkworm-eggs of Bombyx mori (BmHEL) by the method of in silico cloning, SMART cDNA synthesis and RACE-PCR technique. The BmHEL is 974 bp in length, and contains an ORF of 885 bp, encoding 294 amino acids residues.

Characterization of CIb1 gene promoter from silkworm, Bombyx mori.

The hemolymph chymotrypsin inhibitor b1 (CIb1) of silkworm, Bombyx mori, plays an important role in innate immunity. In order to study its encoding gene CIb1, five heterogeneous promoter fragments of 844 bp, 682 bp, 516 bp, 312 bp and 82 bp in length were cloned from genomic DNA of the p50 silkworm strain. Characterization of the CIb1 promoter was performed in vitro using the firefly luciferase gene as reporter.