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Frontiers in Physiology 2019Vitellogenins are a family of yolk proteins that are by far the most abundant among oviparous animals. In the model nematode , the 6 vitellogenins are among the most... (Review)
Review
Vitellogenins are a family of yolk proteins that are by far the most abundant among oviparous animals. In the model nematode , the 6 vitellogenins are among the most highly expressed genes in the adult hermaphrodite intestine, which produces copious yolk to provision eggs. In this article we review what is known about the vitellogenin genes and proteins in , in comparison with vitellogenins in other taxa. We argue that the primary purpose of abundant vitellogenesis in is to support post-embryonic development and fertility, rather than embryogenesis, especially in harsh environments. Increasing vitellogenin provisioning underlies several post-embryonic phenotypic alterations associated with advancing maternal age, demonstrating that vitellogenins can act as an intergenerational signal mediating the influence of parental physiology on progeny. We also review what is known about vitellogenin regulation - how tissue-, sex- and stage-specificity of expression is achieved, how vitellogenins are regulated by major signaling pathways, how vitellogenin expression is affected by extra-intestinal tissues and how environmental experience affects vitellogenesis. Lastly, we speculate whether vitellogenins may play other roles in worm physiology.
PubMed: 31551797
DOI: 10.3389/fphys.2019.01067 -
PLoS Pathogens Dec 2023Microsporidia are a group of obligate intracellular parasites that infect almost all animals, causing serious human diseases and major economic losses to the farming...
Microsporidia are a group of obligate intracellular parasites that infect almost all animals, causing serious human diseases and major economic losses to the farming industry. Nosema bombycis is a typical microsporidium that infects multiple lepidopteran insects via fecal-oral and transovarial transmission (TOT); however, the underlying TOT processes and mechanisms remain unknown. Here, we characterized the TOT process and identified key factors enabling N. bombycis to invade the ovariole and oocyte of silkworm Bombyx mori. We found that the parasites commenced with TOT at the early pupal stage when ovarioles penetrated the ovary wall and were exposed to the hemolymph. Subsequently, the parasites in hemolymph and hemolymph cells firstly infiltrated the ovariole sheath, from where they invaded the oocyte via two routes: (I) infecting follicular cells, thereby penetrating oocytes after proliferation, and (II) infecting nurse cells, thus entering oocytes following replication. In follicle and nurse cells, the parasites restructured and built large vacuoles to deliver themselves into the oocyte. In the whole process, the parasites were coated with B. mori vitellogenin (BmVg) on their surfaces. To investigate the BmVg effects on TOT, we suppressed its expression and found a dramatic decrease of pathogen load in both ovarioles and eggs, suggesting that BmVg plays a crucial role in the TOT. Thereby, we identified the BmVg domains and parasite spore wall proteins (SWPs) mediating the interaction, and demonstrated that the von Willebrand domain (VWD) interacted with SWP12, SWP26 and SWP30, and the unknown function domain (DUF1943) bound with the SWP30. When disrupting these interactions, we found significant reductions of the pathogen load in both ovarioles and eggs, suggesting that the interplays between BmVg and SWPs were vital for the TOT. In conclusion, our study has elucidated key aspects about the microsporidian TOT and revealed the key factors for understanding the molecular mechanisms underlying this transmission.
Topics: Animals; Humans; Vitellogenins; Spores, Fungal; Nosema; Bombyx
PubMed: 38060601
DOI: 10.1371/journal.ppat.1011859 -
Frontiers in Physiology 2019Vitellogenin (Vg) is precursor of vitellin. Here, we identified a () and two -likes (-like1 and -like2) in the brown planthopper, . Phylogenetic analyses showed that...
Vitellogenin (Vg) is precursor of vitellin. Here, we identified a () and two -likes (-like1 and -like2) in the brown planthopper, . Phylogenetic analyses showed that NlVg-like1 and NlVg-like2 are not clustered with the conventional insect Vgs associated with vitellogenesis. Temporo-spatial expression analyses showed that the and -like2 transcript levels increased significantly 24 h after emergence and were primarily expressed in female adults. However, -like1 was expressed during all stages, and in both genders. Tissue-specific analyses showed that all three genes were most highly expressed in the fat body. The injection of double-stranded RNA targeting showed that is essential not only for oocyte development but also for nymph development. The knockdown of -like1 in female adults resulted in failure to hatch or death before eggshell emergence in 18% of offspring embryos, suggesting that -like1 plays an important role during late embryogenesis. Approximately 65% of eggs laid by females that were treated with double-stranded RNA targeting -like2 failed to hatch, indicating that -like2 plays a role in nutrition absorption during oocyte, or embryonic development. Our results illustrate the structural and functional differences among the and -like genes and provide potential targets for RNA-interference-based insect pest management strategies.
PubMed: 31620015
DOI: 10.3389/fphys.2019.01181 -
Toxicology Jun 2022In view of the recurrent applications of pesticides in agricultural producing countries, the increased presence of these substances in the environment raise a demand for...
In view of the recurrent applications of pesticides in agricultural producing countries, the increased presence of these substances in the environment raise a demand for the evaluation of adverse effects on non-target organisms. This study assesses the impact of exposure to five pesticides suspected of being endocrine disruptors (atrazine, 2,4-dichlorophenoxyacetic acid, mancozeb, chlorpyrifos and cypermethrin) on the reproductive development of the nematode Caenorhabditis elegans. To this end, nematodes in the L4 larval stage were exposed to different concentrations of pesticides for 24 h and the consequences on brood size, percentage of gravid nematodes, expression of reproductive-related genes and vitellogenin trafficking and endocytosis were measured. Moreover, 17β-estradiol was used as an estrogenic control for endocrine disrupting compounds throughout the work. The results showed that all the pesticides disturbed to some extent one or more of the evaluated endpoints. Remarkably, we found that atrazine, 2,4-dichlorophenoxyacetic acid and chlorpyrifos produced comparable responses to 17β-estradiol suggesting that these pesticides may have estrogen-like endocrine disrupting activity. Atrazine and 17β-estradiol, as well as 2,4-dichlorophenoxyacetic acid and chlorpyrifos to a lesser extent, decreased the brood size, affected vitellogenin trafficking and endocytosis, and changed the expression of several reproductive-related genes. Conversely, mancozeb and cypermethrin had the least impact on the evaluated endpoint. Cypermethrin affected the brood size at the highest concentration tested and mancozeb altered the distribution of vitellogenin only in approximately 10% of the population. However, both products overexpressed hus-1 and vit-2 genes, indicating that an induction of stress could interfere with the normal development of the nematode. In conclusion, our work proved that C. elegans is a useful biological model to identify the effects of estrogen-like endocrine disruptor compounds, and the sublethal endpoints proposed may serve as an important contribution on evaluating environmental pollutants.
Topics: 2,4-Dichlorophenoxyacetic Acid; Animals; Atrazine; Caenorhabditis elegans; Chlorpyrifos; Endocrine Disruptors; Estradiol; Estrogens; Herbicides; Pesticides; Vitellogenins
PubMed: 35697162
DOI: 10.1016/j.tox.2022.153229 -
Insects Mar 2020The relationship between reproductive diapause and the genes related to vitellogenin (Vg) and its receptor (VgR) in insectoid ovarian development is still unclear....
The relationship between reproductive diapause and the genes related to vitellogenin (Vg) and its receptor (VgR) in insectoid ovarian development is still unclear. Accordingly, in the present study, we used hematoxylin and eosin staining to study the ovarian structure in the predatory mite Neoseiulus barkeri, a species that shows promise as a biological pest control agent. Staining revealed the presence of oocytes on ovary surfaces, and the oocytes were deposited as yolk granules through the intake of Vg and other nutrients with the development of the ovary. Development of the ovary stopped at the oocyte stage in diapausing adult mites, and this stage presented the same characteristics as the first day of adulthood in non-diapause female adults, where oocytes with nutrient cells, but no yolk granules are observed. In order to further explore the effects of the Vg gene and its receptor on reproduction, the sequences of the N. barkeri vitellogenin genes NbVg1, NbVg2, NbVg3, and NbVgR were analyzed using bioinformatics, and the expression levels of the NbVgs and the VgR at different developmental stages were determined by quantitative polymerase chain reaction (qPCR). The results showed that the NbVgs and NbVgR have complete domains and that the positions of many conservative regions and conservative motif are consistent. The expression levels of the NbVgs and NbVgR were highest in the ovipositional period, followed by those in the preovipositional period. The expression levels of the NbVgs and the VgR in non-diapause female adult mites were significantly higher than those in reproductive diapause female adult mites.
PubMed: 32225063
DOI: 10.3390/insects11040203 -
Experimental & Applied Acarology Mar 2022Vitellogenin (Vg) is an important factor that impacts oocyte maturation, egg formation and embryonic development in Arthropoda. Two orthologs of Vg gene were obtained...
Vitellogenin (Vg) is an important factor that impacts oocyte maturation, egg formation and embryonic development in Arthropoda. Two orthologs of Vg gene were obtained from the genome of Phytoseiulus persimilis and termed as PpVg1 and PpVg2. Both orthologs belong to the large lipid transfer protein superfamily. The expression of PpVg1 and PpVg2 was low in immatures and male adults, and increased rapidly in female adults after mating, and reached a peak before the first egg was laid (168× and 20.5× the level in virgin females, respectively). When PpVg1 and PpVg2 were interfered with dsRNA, the relative expression decreased by 81.0 and 30.9%, respectively, and 7.8 and 31.4% interfered individuals died within 24 h. Among surviving individuals, ca. 51.1 and 44.8% are infertile. Factors that might be related to expression of Vg genes are also discussed.
Topics: Animals; Female; Male; Mites; Reproduction; Vitellogenins
PubMed: 35239074
DOI: 10.1007/s10493-022-00698-8 -
Microbiology Spectrum Aug 2022Liberibacter solanacearum (CLso) haplotype D, transmitted by the carrot psyllid , is a major constraint for carrot production in Israel. Unveiling the molecular...
Liberibacter solanacearum (CLso) haplotype D, transmitted by the carrot psyllid , is a major constraint for carrot production in Israel. Unveiling the molecular interactions between the psyllid vector and CLso can facilitate the development of nonchemical approaches for controlling the disease caused by CLso. Bacterial surface proteins are often known to be involved in adhesion and virulence; however, interactions of CLso with carrot psyllid proteins that have a role in the transmission process has remained unexplored. In this study, we used CLso outer membrane protein (OmpA) and flagellin as baits to screen for psyllid interacting proteins in a yeast two-hybrid system assay. We identified psyllid vitellogenin (Vg) to interact with both OmpA and flagellin of CLso. As Vg and autophagy are often tightly linked, we also studied the expression of autophagy-related genes to further elucidate this interaction. We used the juvenile hormone (JH-III) to induce the expression of Vg, thapsigargin for suppressing autophagy, and rapamycin for inducing autophagy. The results revealed that Vg negatively regulates autophagy. Induced Vg expression significantly suppressed autophagy-related gene expression and the levels of CLso significantly increased, resulting in a significant mortality of the insect. Although the specific role of Vg remains obscure, the findings presented here identify Vg as an important component in the insect immune responses against CLso and may help in understanding the initial molecular response in the vector against Liberibacter. Pathogen transmission by vectors involves multiple levels of interactions, and for the transmission of liberibacter species by psyllid vectors, much of these interactions are yet to be explored. Liberibacter solanacearum (CLso) haplotype D inflicts severe economic losses to the carrot industry. Understanding the specific interactions at different stages of infection is hence fundamental and could lead to the development of better management strategies to disrupt the transmission of the bacteria to new host plants. Here, we show that two liberibacter membrane proteins interact with psyllid vitellogenin and also induce autophagy. Altering vitellogenin expression directly influences autophagy and CLso abundance in the psyllid vector. Although the exact mechanism underlying this interaction remains unclear, this study highlights the importance of immune responses in the transmission of this disease agent.
Topics: Animals; Autophagy; Flagellin; Hemiptera; Liberibacter; Plant Diseases; Rhizobiaceae; Vitellogenins
PubMed: 35863005
DOI: 10.1128/spectrum.01577-22 -
Current Opinion in Insect Science Oct 2023Honeybees are highly organized eusocial insects displaying a distinct division of labor. Juvenile hormone (JH) has long been hypothesized to be the major driver of... (Review)
Review
Honeybees are highly organized eusocial insects displaying a distinct division of labor. Juvenile hormone (JH) has long been hypothesized to be the major driver of behavioral transitions. However, more and more experiments in recent years have suggested that the role of this hormone is not as fundamental as hypothesized. Vitellogenin, a common egg yolk precursor protein, seems to be the major regulator of division of labor in honeybees, in connection with nutrition and the neurohormone and transmitter octopamine. Here, we review the role of vitellogenin in controlling honeybee division of labor and its modulation by JH, nutrition, and the catecholamine octopamine.
PubMed: 37391163
DOI: 10.1016/j.cois.2023.101080 -
International Journal of Molecular... Oct 2022The fall armyworm is a highly polyphagous invasive pest. The strong reproductive capacity is an important factor in the rapid colonization and expansion of...
The fall armyworm is a highly polyphagous invasive pest. The strong reproductive capacity is an important factor in the rapid colonization and expansion of Vitellogenin (Vg) and vitellogenin receptor (VgR) play important roles in insect reproduction. As the precursor of vitellin (Vn), Vg provides essential nutrition for embryonic development, and VgR mediates the uptake of Vg by oocytes. In this context, we cloned and characterized these two genes of ( and ) and evaluated their expression profiles in different developmental stages and tissues. The RNA interference experiment was used to investigate their function in vitellogenesis. The ORF values of and were 5250 and 5445 bp, encoding 1749 and 1815 amino acid residues, respectively. The qRT-PCR results revealed that both and were highly expressed in female adults; was specifically expressed in the fat body, whereas was highly expressed in the ovary. In addition, the depletion of either or hindered oocyte maturation and ovarian development, leading to a significant decrease in fecundity. The present study reveals the importance of and in the vitellogenesis of , laying a theoretical foundation for the development of pollution-free pest control strategies with and as new targets.
Topics: Amino Acids; Animals; Female; Spodoptera; Vitellins; Vitellogenesis; Vitellogenins
PubMed: 36233286
DOI: 10.3390/ijms231911972 -
Biology of Reproduction Apr 2024In oviparous animals, egg yolk is largely derived from vitellogenin, which is taken up from the maternal circulation by the growing oocytes via the vitellogenin...
In oviparous animals, egg yolk is largely derived from vitellogenin, which is taken up from the maternal circulation by the growing oocytes via the vitellogenin receptor. Recently, a novel member of the lipoprotein receptor superfamily termed low-density lipoprotein receptor-related protein 13 was identified and proposed as a candidate of vitellogenin receptor in oviparous animals. However, the roles of low-density lipoprotein receptor-related protein 13 in vitellogenesis are still poorly defined. Here, we investigated the expression, vitellogenin-binding properties, and function of low-density lipoprotein receptor-related protein 13 in zebrafish. Two different lrp13 genes termed lrp13a and lrp13b were found in zebrafish. Reverse transcription polymerase chain reaction and quantitative polymerase chain reaction revealed both lrp13s to be predominantly expressed in zebrafish ovary, and in situ hybridization detected both lrp13s transcripts in the ooplasm of early stage oocytes. Two yeast hybrid studies showed that among eight vitellogenins of zebrafish, Vtg1, 2, and 3 bind to Lrp13a, while Vtg1, 2, and 5 bind to Lrp13b. We created zebrafish lrp13a and lrp13b mutant lines using CRISPR/Cas9. Knockout of lrp13a leads to a male-biased sex ratio and decreased diameter of embryo yolk, while knockout of lrp13b and double knockout of lrp13a and lrp13b leads to the delay of vitellogenesis, followed by follicular atresia. These phenotypes of mutants can be explained by the disruption of vitellogenesis in the absence of Lrp13s. Taken together, our results indicate that both Lrp13a and Lrp13b can serve as vitellogenin receptors in zebrafish among other vitellogenin receptors that are not yet described.
PubMed: 38660750
DOI: 10.1093/biolre/ioae040