scholarly journals E93 expression and links to the juvenile hormone in hemipteran mealybugs with insights on female neoteny

2018 ◽  
Author(s):  
Isabelle Mifom Vea ◽  
Sayumi Tanaka ◽  
Tomohiro Tsuji ◽  
Takahiro Shiotsuki ◽  
Akiya Jouraku ◽  
...  

AbstractInsect metamorphosis generates reproductive adults and is commonly accompanied by the direct or indirect development of wings. In some winged insects, the imago is altered by life history changes. For instance, in scale insects and mealybugs, reproductive females retain juvenile features and are wingless. The transcription factor E93 triggers metamorphosis and plays in concert with the juvenile hormone pathway to guarantee the successful transition from juvenile to adult. We previously provided evidence of an atypical down-regulation of the juvenile hormone pathway during female adult development in the Japanese mealybug. Here, we further investigate how E93 is involved in the production of neotenic wingless females, by identifying its isoforms, assessing their expression patterns and evaluating the effect of exogenous juvenile hormone mimic treatment on E93. This study identifies three E93 isoforms on the 5’ end based on Japanese mealybug cDNA and shows that female development occurs with the near absence of E93 transcripts, as opposed to male metamorphosis. Additionally, while male development is typically affected by exogenous juvenile hormone mimic treatments, females seem to remain insensitive to the treatment, and up-regulation of the juvenile hormone signaling is not observed. Furthermore, juvenile hormone mimic treatment on female nymphs did not have obvious effect on E93 transcription, while treatment on male prepupae resulted in decreased E93 transcripts. In this study, we emphasize the importance of examining cases of atypical metamorphosis as complementary systems to provide a better understanding on the molecular mechanisms underlying insect metamorphosis. For instance, the factors regulating the expression of E93 are largely unclear. Investigating the regulatory mechanism of E93 transcription could provide clues towards identifying the factors that induce or suppress E93 transcription, in turn triggering male adult development or female neoteny.Graphical abstractHighlights- Neotenic female Planococcus kraunhiae (Japanese mealybug) develops with low E93 expression.- E93 expression pattern during male development is typical to other insects.- Juvenile hormone mimic treatment on male prepupae results in decreased E93 transcripts.- Juvenile hormone mimic treatment on female nymphs does not have obvious effects on E93 transcription.- Female mealybugs have low sensitivity to juvenile hormone mimic treatments compared to males and other insects.


2017 ◽  
Vol 114 (5) ◽  
pp. 1057-1062 ◽  
Author(s):  
Takumi Kayukawa ◽  
Akiya Jouraku ◽  
Yuka Ito ◽  
Tetsuro Shinoda

Juvenile hormone (JH) represses precocious metamorphosis of larval to pupal and adult transitions in holometabolous insects. The early JH-inducible geneKrüppel homolog 1(Kr-h1) plays a key role in the repression of metamorphosis as a mediator of JH action. Previous studies demonstrated that Kr-h1 inhibits precocious larval–pupal transition in immature larva via direct transcriptional repression of the pupal specifierBroad-Complex(BR-C). JH was recently reported to repress the adult specifier geneEcdysone-induced protein 93F(E93); however, its mechanism of action remains unclear. Here, we found that JH suppressed ecdysone-inducibleE93expression in the epidermis of the silkwormBombyx moriand in aB. moricell line. Reporter assays in the cell line revealed that the JH-dependent suppression was mediated by Kr-h1. Genome-wide ChIP-seq analysis identified a consensus Kr-h1 binding site (KBS, 14 bp) located in theE93promoter region, and EMSA confirmed that Kr-h1 directly binds to the KBS. Moreover, we identified a C-terminal conserved domain in Kr-h1 essential for the transcriptional repression ofE93. Based on these results, we propose a mechanism in which JH-inducible Kr-h1 directly binds to the KBS site upstream of theE93locus to repress its transcription in a cell-autonomous manner, thereby preventing larva from bypassing the pupal stage and progressing to precocious adult development. These findings help to elucidate the molecular mechanisms regulating the metamorphic genetic network, including the functional significance ofKr-h1,BR-C, andE93in holometabolous insect metamorphosis.



1969 ◽  
Vol 47 (5) ◽  
pp. 917-920 ◽  
Author(s):  
T. S. Sahota

Simplified preparations, such as isolated abdomens, were used to study the effect of farnesyl methyl ether (a juvenile hormone mimic) and ecdysone on ovarian development and adult development in Malacosoma pluviale. Untreated isolated abdomens showed very limited ovarian development and failed to form imaginal cuticle, thus indicating a lack of adult development. Topical application of farnesyl methyl ether to the isolated abdomens blocked the ovarian development completely and no adult development ensued either. Both adult development and ovarian development of the isolated abdomens were stimulated by ecdysone injections. Thus, adult development and ovarian development in M. pluviale seem to be closely related.



Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2259-2269 ◽  
Author(s):  
Xiaofeng Zhou ◽  
Lynn M. Riddiford

The understanding of the molecular basis of the endocrine control of insect metamorphosis has been hampered by the profound differences in responses of the Lepidoptera and the Diptera to juvenile hormone (JH). In both Manduca and Drosophila, the broad (br) gene is expressed in the epidermis during the formation of the pupa, but not during adult differentiation. Misexpression of BR-Z1 during either a larval or an adult molt of Drosophila suppressed stage-specific cuticle genes and activated pupal cuticle genes, showing that br is a major specifier of the pupal stage. Treatment with a JH mimic at the onset of the adult molt causes br re-expression and the formation of a second pupal cuticle in Manduca, but only in the abdomen of Drosophila. Expression of the BR isoforms during adult development of Drosophila suppressed bristle and hair formation when induced early or redirected cuticle production toward the pupal program when induced late. Expression of BR-Z1 at both of these times mimicked the effect of JH application but, unlike JH, it caused production of a new pupal cuticle on the head and thorax as well as on the abdomen. Consequently, the ‘status quo’ action of JH on the pupal-adult transformation is mediated by the JH-induced re-expression of BR.



2019 ◽  
Vol 374 (1783) ◽  
pp. 20190064 ◽  
Author(s):  
Marek Jindra

Insect metamorphosis boasts spectacular cases of postembryonic development when juveniles undergo massive morphogenesis before attaining the adult form and function; in moths or flies the larvae do not even remotely resemble their adult parents. A selective advantage of complete metamorphosis (holometaboly) is that within one species the two forms with different lifestyles can exploit diverse habitats. It was the environmental adaptation and specialization of larvae, primarily the delay and internalization of wing development, that eventually required an intermediate stage that we call a pupa. It is a long-held and parsimonious hypothesis that the holometabolous pupa evolved through modification of a final juvenile stage of an ancestor developing through incomplete metamorphosis (hemimetaboly). Alternative hypotheses see the pupa as an equivalent of all hemimetabolous moulting cycles (instars) collapsed into one, and consider any preceding holometabolous larval instars free-living embryos stalled in development. Discoveries on juvenile hormone signalling that controls metamorphosis grant new support to the former hypothesis deriving the pupa from a final pre-adult stage. The timing of expression of genes that repress and promote adult development downstream of hormonal signals supports homology between postembryonic stages of hemimetabolous and holometabolous insects. This article is part of the theme issue ‘The evolution of complete metamorphosis’.



2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Chao Liu ◽  
An-Song Liu ◽  
Da Zhong ◽  
Cheng-Gong Wang ◽  
Mi Yu ◽  
...  

AbstractBone marrow-derived mesenchymal stem cells (BM-MSCs), the common progenitor cells of adipocytes and osteoblasts, have been recognized as the key mediator during bone formation. Herein, our study aim to investigate molecular mechanisms underlying circular RNA (circRNA) AFF4 (circ_AFF4)-regulated BM-MSCs osteogenesis. BM-MSCs were characterized by FACS, ARS, and ALP staining. Expression patterns of circ_AFF4, miR-135a-5p, FNDC5/Irisin, SMAD1/5, and osteogenesis markers, including ALP, BMP4, RUNX2, Spp1, and Colla1 were detected by qRT-PCR, western blot, or immunofluorescence staining, respectively. Interactions between circ_AFF4 and miR-135a-5p, FNDC5, and miR-135a-5p were analyzed using web tools including TargetScan, miRanda, and miRDB, and further confirmed by luciferase reporter assay and RNA pull-down. Complex formation between Irisin and Integrin αV was verified by Co-immunoprecipitation. To further verify the functional role of circ_AFF4 in vivo during bone formation, we conducted animal experiments harboring circ_AFF4 knockdown, and born samples were evaluated by immunohistochemistry, hematoxylin and eosin, and Masson staining. Circ_AFF4 was upregulated upon osteogenic differentiation induction in BM-MSCs, and miR-135a-5p expression declined as differentiation proceeds. Circ_AFF4 knockdown significantly inhibited osteogenesis potential in BM-MSCs. Circ_AFF4 stimulated FNDC5/Irisin expression through complementary binding to its downstream target molecule miR-135a-5p. Irisin formed an intermolecular complex with Integrin αV and activated the SMAD1/5 pathway during osteogenic differentiation. Our work revealed that circ_AFF4, acting as a sponge of miR-135a-5p, triggers the promotion of FNDC5/Irisin via activating the SMAD1/5 pathway to induce osteogenic differentiation in BM-MSCs. These findings gained a deeper insight into the circRNA-miRNA regulatory system in the bone marrow microenvironment and may improve our understanding of bone formation-related diseases at physiological and pathological levels.



Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 896
Author(s):  
Yuenan Zhou ◽  
Pei Yang ◽  
Shuang Xie ◽  
Min Shi ◽  
Jianhua Huang ◽  
...  

The endoparasitic wasp Cotesia vestalis is an important biological agent for controlling the population of Plutella xylostella, a major pest of cruciferous crops worldwide. Though the genome of C. vestalis has recently been reported, molecular mechanisms associated with sexual development have not been comprehensively studied. Here, we combined PacBio Iso-Seq and Illumina RNA-Seq to perform genome-wide profiling of pharate adult and adult development of male and female C. vestalis. Taking advantage of Iso-Seq full-length reads, we identified 14,466 novel transcripts as well as 8770 lncRNAs, with many lncRNAs showing a sex- and stage-specific expression pattern. The differentially expressed gene (DEG) analyses showed 2125 stage-specific and 326 sex-specific expressed genes. We also found that 4819 genes showed 11,856 alternative splicing events through combining the Iso-Seq and RNA-Seq data. The results of comparative analyses showed that most genes were alternatively spliced across developmental stages, and alternative splicing (AS) events were more prevalent in females than in males. Furthermore, we identified six sex-determining genes in this parasitic wasp and verified their sex-specific alternative splicing profiles. Specifically, the characterization of feminizer and doublesex splicing between male and female implies a conserved regulation mechanism of sexual development in parasitic wasps.



2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Franziska Eberl ◽  
Thomas Fabisch ◽  
Katrin Luck ◽  
Tobias G. Köllner ◽  
Heiko Vogel ◽  
...  

Abstract Background Protease inhibitors are defense proteins widely distributed in the plant kingdom. By reducing the activity of digestive enzymes in insect guts, they reduce the availability of nutrients and thus impair the growth and development of the attacking herbivore. One well-characterized class of protease inhibitors are Kunitz-type trypsin inhibitors (KTIs), which have been described in various plant species, including Populus spp. Long-lived woody perennials like poplar trees encounter a huge diversity of herbivores, but the specificity of tree defenses towards different herbivore species is hardly studied. We therefore aimed to investigate the induction of KTIs in black poplar (P. nigra) leaves upon herbivory by three different chewing herbivores, Lymantria dispar and Amata mogadorensis caterpillars, and Phratora vulgatissima beetles. Results We identified and generated full-length cDNA sequences of 17 KTIs that are upregulated upon herbivory in black poplar leaves, and analyzed the expression patterns of the eight most up-regulated KTIs via qRT-PCR. We found that beetles elicited higher transcriptional induction of KTIs than caterpillars, and that both caterpillar species induced similar KTI expression levels. Furthermore, KTI expression strongly correlated with the trypsin-inhibiting activity in the herbivore-damaged leaves, but was not dependent on damage severity, i.e. leaf area loss, for most of the genes. Conclusions We conclude that the induction of KTIs in black poplar is controlled at the transcriptional level in a threshold-based manner and is strongly influenced by the species identity of the herbivore. However, the underlying molecular mechanisms and ecological consequences of these patterns remain to be investigated.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yinjie Wang ◽  
Yongxia Zhang ◽  
Qingquan Liu ◽  
Haiying Tong ◽  
Ting Zhang ◽  
...  

AbstractIris germanica L. is a perennial herbaceous plant that has been widely cultivated worldwide and is popular for its elegant and vibrantly colorful flowers. Selection of appropriate reference genes is the prerequisite for accurate normalization of target gene expression by quantitative real-time PCR. However, to date, the most suitable reference genes for flowering stages have not been elucidated in I. germanica. In this study, eight candidate reference genes were examined for the normalization of RT-qPCR in three I. germanica cultivars, and their stability were evaluated by four different algorithms (GeNorm, NormFinder, BestKeeper, and Ref-finder). The results revealed that IgUBC and IgGAPDH were the most stable reference genes in ‘00246’ and ‘Elizabeth’, and IgTUB and IgUBC showed stable expression in ‘2010200’. IgUBC and IgGAPDH were the most stable in all samples, while IgUBQ showed the least stability. Finally, to validate the reliability of the selected reference genes, the expression patterns of IgFT (Flowering Locus T gene) was analyzed and emphasized the importance of appropriate reference gene selection. This work presented the first systematic study of reference genes selection during flower bud development and provided guidance to research of the molecular mechanisms of flowering stages in I. germanica.



1975 ◽  
Vol 26 (2-3) ◽  
pp. 105-111 ◽  
Author(s):  
Kazuo BUEI ◽  
Sumiyo ITO ◽  
Takashi YAMADA ◽  
Shinichi GAMO ◽  
Masaaki KATO


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Songbai Yang ◽  
Xiaolong Zhou ◽  
Yue Pei ◽  
Han Wang ◽  
Ke He ◽  
...  

Estrus is an important factor for the fecundity of sows, and it is involved in ovulation and hormone secretion in ovaries. To better understand the molecular mechanisms of porcine estrus, the expression patterns of ovarian mRNA at proestrus and estrus stages were analyzed using RNA sequencing technology. A total of 2,167 differentially expressed genes (DEGs) were identified (P≤0.05, log2  Ratio≥1), of which 784 were upregulated and 1,383 were downregulated in the estrus compared with the proestrus group. Gene Ontology (GO) enrichment indicated that these DEGs were mainly involved in the cellular process, single-organism process, cell and cell part, and binding and metabolic process. In addition, a pathway analysis showed that these DEGs were significantly enriched in 33 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, including cell adhesion molecules, ECM-receptor interaction, and cytokine-cytokine receptor interaction. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) confirmed the differential expression of 10 selected DEGs. Many of the novel candidate genes identified in this study will be valuable for understanding the molecular mechanisms of the sow estrous cycle.



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