yongping huang insect

Uric acid is the end-product of nitrogen metabolism of the silkworm and other lepidopterans. The accumulation of uric acid particles in the epidermis causes the larval silkworm to appear white and opaque. However, the mechanism of uric acid granule formation is still unclear. Silkworm epidermis color is linked to the genes responsible for uric acid particle formation. We first identified two genes in the Bombyx mori genome that encode subunits of the Bloc-1 (Biogenesis of Lysosome-related Organelles Complex-1) by homology to these genes in other eukaryotes, Bmpali and Bmb1...

The reproductive process in various species has undergone evolutionary adaptations at both the physiological and molecular levels, playing a significant role in maintaining their populations. In lepidopteran insects, the spermatophore is a unique structure formed in the female reproductive system, in which sperm storage and activation take place. It is known that the formation of the spermatophore is regulated by seminal fluid proteins derived from males. However, studies investigating the genetic mechanisms behind spermatophore formation in lepidopterans have been limited...

Black soldier fly (BSF), Hermetia illucens (L.) (Diptera: Stratiomyidae), is a promising bio-agent to transform organic wastes into valuable insect biomass, and the intestinal microbes play an essential role in this process. Here, we report that Citrobacter amalonaticus , a Gram-negative gut commensal bacterium of BSF larvae, can colonize the whole intestines of the larva and significantly promote the larval growth and development. The bacterial association with the larva had a marked impact on the larval transcriptome and modulated the expression of genes involved in dozens of biological pathways including host macro-nutrient metabolism and immune response...

The Masculinizer gene, Masc, encodes a lepidopteran-specific novel CCCH-type zinc finger protein, which controls sex determination and dosage compensation in Bombyx mori. Considering the potential application of it in pest control, it is necessary to investigate the function of Masc gene in Hyphantria cunea, a globally invasive forest pest. In the present study, we identified and functionally characterized the Masc gene, HcMasc, in H. cunea. Sequence analysis revealed that HcMASC contained the conserved CCCH-type zinc finger domain, nuclear localization signal, and male determining domain, in which the last was confirmed to be required for its masculinization in BmN cell line...

After a millennium of domestication, numerous silkworm mutants have emerged that exhibit transparent epidermis, which is caused by abnormally low levels of uric acid. We identified the Bombyx mori gene Bmcap (BMSK0003832) as the homolog of cappuccino, a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1) that has been extensively characterized in human, mouse, and insect species, by analyzing the amino acid sequences of putative purine metabolism genes. Using the clustered regularly interspaced palindromic repeats (CRISPR) / CRISPR-associated protein 9 system, we disrupted Bmcap, resulting in decreased uric acid levels in the silkworm epidermis and a translucent skin phenotype...

MicroRNAs (miRNAs) are important regulators of nearly all aspects of biological processes in eukaryotes. During the biogenesis of miRNAs, the RNase III enzyme Dicer processes double-strand precursor miRNAs into mature miRNAs and promotes the assembly of RNA-induced silencing complexes. Dicer has been reported to participate in a wide range of physiological processes, including development and immunity, in some insect species. However, the physiological roles of Dicer in lepidopterans remain poorly understood...

Sex-determination pathways are extremely diverse. Understanding the mechanism of sex determination in insects is important for genetic manipulation of the pest population and for breeding of economically valuable insects. Although sex determination has been well characterized in the model species Drosophila melanogaster, little is known about this pathway in Stratiomyidae. In the present study, we first identified the Drosophila intersex (ix) homolog in Hermetia illucens, also known as the black soldier fly, which belongs to the Stratiomyidae family and which is an important insect for the conversion of various organic wastes...

In lepidopteran insects, dichotomous spermatogenesis produces eupyrene spermatozoa, which are nucleated, and apyrene spermatozoa, which are anucleated. Both sperm morphs are essential for fertilization, as eupyrene sperm fertilize the egg, and apyrene sperm is necessary for the migration of eupyrene sperm. In Drosophila, Prmt5 acts as a type II arginine methyltransferase that catalyzes the symmetrical dimethylation of arginine residues in the RNA helicase Vasa. Prmt5 is critical for the regulation of spermatogenesis, but Vasa is not...

The black soldier fly (BSF), Hermetia illucens, is a promising insect for mitigating solid waste problems as its larvae are able to bioconvert organic waste into valuable biomass. We recently reported a high-quality genome assembly of the BSF; analysis of this genome sequence will further the understanding of insect biology and identify genes that can be manipulated to improve efficiency of bioconversion. To enable genetic manipulation of the BSF, we have established the first transgenic methods for this economically important insect...

The evolution of feeding habits leads to speciation in insects. Bactrocera true fruit flies display diverse feeding habits across species. We combine behavioral and functional genomic studies to probe the divergence between the specialist B. minax and the generalist B. dorsalis. We find that both vision and olfaction contribute to their respective host preferences, with a dominant effect of vision over the olfaction in short range. Correspondingly, host location-related genes are significantly enriched in the phototransduction pathway, of which the long-wavelength rhodopsin confers the color preference in both species and has been subject to selection in the specialist...

In lepidopteran insects, sperm dimorphism is a remarkable feature, in which males exhibit two different types of sperms. Both sperm morphs are essential for fertilization: Eupyrene sperm carry DNA and fertilize eggs, whereas apyrene sperm, which do not have nuclei, are necessary for transport of eupyrene sperm into eggs. In this study, we showed that the gene BmHen1, which encodes a methyltransferase that modifies piRNAs, is necessary for eupyrene sperm development in the lepidopteran model insect, Bombyx mori...

Male fertility is essential for reproduction and population growth in animals. Many factors affect male fertility, such as courtship behavior, sperm quantity, and sperm motility, among others. Seminal Fluid Proteins (SFPs) are vital components of seminal fluid in the male ejaculate, which affect male fertility, sperm activation, and female ovulation. However, the knowledge of SFPs is insufficient; the function of many SFPs remains unknown, and most described functions were mainly characterized in Drosophila or other laboratory models...

Sex determination is an important and traditional biological process. In Lepidoptera, Masculinizer ( Masc ) and doublesex ( dsx ) are the essential genes for sex determination and play critical roles in sexual differentiation and development. The functions of Masc and dsx have been characterized in several model insect species. However, the molecular mechanism and sex determination functions of Masc and dsx in Ostrinia furnacalis , an agricultural pest, are still unknown. Here, we successfully used the CRISPR/Cas9 genome editing system to knock out OfMasc and Ofdsx ...

As a defense mechanism against transposable elements, the PIWI-interacting RNA (piRNA) pathway maintains genomic integrity and ensures proper gametogenesis in gonads. Numerous factors are orchestrated to ensure normal operation of the piRNA pathway. Spindle-E (Spn-E) gene was one of the first genes shown to participate in the piRNA pathway. In this study, we performed functional analysis of Spn-E in the model lepidopteran insect, Bombyx mori. Unlike the germline-specific expression pattern observed in Drosophila and mouse, BmSpn-E was ubiquitously expressed in all tissues tested, and it was highly expressed in gonads...

Bombyx mori nucleopolyhedrovirus (BmNPV) is a pathogen that causes severe disease in silkworms. In a previous study, we demonstrated that by using the CRISPR/Cas9 system to disrupt the BmNPV ie-1 and me53 genes, transgenic silkworms showed resistance to BmNPV infection. Here, we used the same strategy to simultaneously target lef8 and lef9 , which are essential for BmNPV replication. A PCR assay confirmed that double-stranded breaks were induced in viral DNA at targeted sequences in BmNPV-infected transgenic silkworms that expressed small guide RNAs (sgRNAs) and Cas9...

Sperm deliver the male complement of DNA to the ovum, and thus play a key role in sexual reproduction. Accordingly, spermatogenesis has outstanding significance in fields as disparate as infertility treatments and pest-control, making it a broadly interesting and important focus for molecular genetics research in a wide range of species. Here we investigate spermatogenesis in the model lepidopteran insect Bombyx mori (silkworm moth), with particular focus on the gene PMFBP1 (polyamine modulated factor 1 binding protein 1)...

Fall webworm, Hyphantria cunea, is a global invasive forest pest that causes serious damage to the economy and ecosystem of agriculture and forestry. Due to the extent of the problem and the difficulty of conventional chemical control, new technologies must be pursued, such as genetic-based inheritable insect sterile technology (gSIT), which exhibits promise for pest control. In the present study, we established a piggyBac-based transgenic system in fall webworm and generated a dominant male-sterile strain by targeting the seminal fluid protein serine protease 2 (Hcser2), displaying an outstanding trait of gSIT...

The silkworm Bombyx mori is an economically important insect. The sericulture industry is seriously affected by pathogen infections. Of these pathogens, Bombyx mori nucleopolyhedrovirus (BmNPV) causes approximately 80% of the total economic losses due to pathogen infections. We previously constructed a BmNPV-specific CRISPR/Cas9 silkworm line with significantly enhanced resistance to BmNPV. In order to optimize the resistance properties and minimize its impact on economic traits, we constructed an inducible CRISPR/Cas9 system for use in transgenic silkworms...

The silkworm (Bombyx mori) is a domesticated and economically important insect. During the whole growth period, silkworm suffers various pathogen infection. Nearly 80% of silk cocoon crop losses are attributed to viral diseases. The circular double-stranded DNA virus Bombyx mori nuclepolyhedrovirus (BmNPV) is the major viral pathogen responsible for massive silkworm death and huge economic losses in the sericulture industry. Up to now, almost all the new strategies for developing immunity against BmNPV are in laboratory strains because of the lack of transgenic technology in industrial silkworm strains...

The black cutworm (BCW), Agrotis ipsilon, is a worldwide polyphagous and underground pest that causes a high level of economic loss to a wide range of crops through the damage of roots. This species performs non-directed migration throughout East and Southeast Asia seasonally. Lack of a genome information has limited further studies on its unique biology and the development of novel management approaches. In this study, we present a 476 Mb de novo assembly of BCW, along with a consensus gene set of 14,801 protein-coding gene models...