Search

Simple Summary: Fruit flies are major pests that cause extensive damage to fruits and vegetables worldwide. Understanding how these insects respond to heat treatment is crucial for developing effective methods to control them. In this study, we investigated how the Queensland fruit fly and the Mediterranean fruit fly react at a molecular level when exposed to heat. We found that each species responds differently, activating different genes to cope with the stress. By identifying the specific genes involved, we can design targeted heat treatments that are more effective for each species. This tailored approach can improve the efficiency of pest control, reduce the need for harmful chemicals, and minimise damage to the environment. Our findings offer valuable insights for developing better strategies to manage fruit fly populations, ensuring healthier crops and reducing economic losses for farmers. This research highlights the importance of understanding species-specific responses to stress and provides a foundation for future studies aimed at optimising pest management techniques. Invasive Tephritid fruit flies rank among the most destructive agricultural and horticultural pests worldwide. Heat treatment is commonly employed as a post-harvest method to exterminate fruit flies in fruits or vegetables. These pest species exhibit distinct tolerance to heat treatments, suggesting that the molecular pathways affected by heat may differ among species. In this study, the Queensland fruit fly (Qfly), Bactrocera tryoni, was utilised as a model investigate its molecular response to heat stress through heat bioassays. RNA samples from flies before and after heat treatment were extracted and sequenced to identify genes with significant changes in expression. These findings were compared to another serious Tephritid fruit fly species, the Mediterranean fruit fly (Medfly), Ceratitis capitata, under similar heat treatment conditions. The analysis reveals only three common genes: heat shock protein 70 (HSP70), HSP68, and 14-3-3 zeta protein. However, despite these shared genes, their expression patterns differ between Qfly and Medfly. This suggests that these genes might play different roles in the heat responses of each species and could be regulated differently. This study presents the first evidence of differing molecular responses to heat between Qfly and Medfly, potentially linked to their varied origins, habitats, and genetic backgrounds. These findings offer new insights into Tephritid fruit fly responses to heat at the molecular level, which may help refine post-harvest strategies to control these pests in the future. [ABSTRACT FROM AUTHOR]

Insects utilize sugars as their essential energy and nutrient sources; therefore, the sense of sugar detection plays a critical role in insect behaviours. Previously, using genomic and transcriptomic approaches, we identified eight putative sugar gustatory receptor (GR) genes from the cotton bollworm Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae). Here, we further validated these annotated sugar receptor genes (HarmGr4-HarmGr8 and HarmGr10-HarmGr12) and found HarmGr10 may be a pseudogene carrying a stop codon in the open reading frame. Sequence alignment revealed H. armigera sugar GR sequences are conserved at C-terminus and phylogenetic analysis showed that insect sugar GRs have evolved in a family-specific manner. Interestingly, all eight H. armigera sugar GRs are localized in a tandem array on the same scaffold of the genome. In silico gene expression and reverse transcription (RT)-PCR analysis showed that HarmGr10 is specifically expressed in male adult testes while HarmGr11 is specifically expressed in female adult ovaries, suggesting H. armigera sugar GRs may be involved in reproduction-related functions. This study improves our knowledge on insect sugar receptors and gustatory systems. Key words: gustatory receptor, sugar receptor, Helicoverpa armigera, gene expression. Résumé : Les insectes utilisent les sucres comme source essentielle d'énergie et de nutrition. Ainsi, la détection des sucres joue un rôle critique dans les comportements des insectes. Antérieurement, à l'aide d'approches génomiques et transcriptomiques, les auteurs avaient identifié huit gènes candidats pour des récepteurs gustatifs (GR) de sucres chez la noctuelle de la tomate Helicoverpa armigera (Hübner) (Lepidoptera : Noctuidae). Dans ce travail, les auteurs ont validé davantage ces gènes annotés comme codant pour des récepteurs de sucres (HarmGr4-HarmGr8 et HarmGr10-HarmGr12) et ont trouvé que le HarmGr10 est possiblement un pseudogène du fait qu'il contient un codon stop au sein du cadre de lecture. Un alignement des séquences a révélé que les séquences des GR de sucres chez le H. armigera sont conservées à leur extrémité C-terminale et une analyse phylogénétique a montré que les GR de sucres auraient évolué pour former des familles. Fait intéressant, tous les GR de sucres du H. armigera sont groupés en tandem sur le même segment du génome. Une analyse in silico de leur expression et des analyses (RT)-PCR ont montré que le HarmGr10 est spécifiquement exprimé au sein des testicules des mâles adultes tandis que le HarmGr11 était spécifiquement exprimé au sein des ovaires des femelles adultes; ce qui suggère que les GR de sucres chez le H. armigera seraient impliqués dans des fonctions liées à la reproduction. Cette étude contribue à une meilleure connaissance des récepteurs de sucres et des systèmes gustatifs chez les insectes. [Traduit par la Rédaction] Mots-clés : récepteur gustatif, récepteur de sucres, Helicoverpa armigera, expression génique., Introduction Sugars play critical roles in insect life as valuable energy and food resources. For example, bees collect nectar from blossoms in the field and convert them into honey, which [...]

Postnatal modeling of the intestinal epithelium has long-term impacts on the healthy development of infants and relies largely on nutrient composition of the diet. Lactoferrin (Lf) is among the various human milk trophic factors that facilitate the infant intestinal adaptation. Hydrolysis of Lf is minimal at the prevailing postprandial pH of infants, and Lf may therefore have greater biological potential in infants than in adults. Lf bidirectionally stimulates concentration- dependent proliferation and differentiation of small intestinal epithelial cells, and therefore affects small intestinal mass, length, and epithelial digestive enzyme expression. A 105 kDa Lf receptor (LfR) specifically mediates the uptake of Lf into enterocytes and crypt cells. Mechanistically, the complex of Lf and LfR is internalized through clathrin-mediated endocytosis; both iron-free apo-Lf and iron-saturated holo-Lf activate the PI3K/Akt pathway, whereas only apo-Lf triggers ERK1/2 signaling. Lf enters the nucleus, where it can stimulate thymidine incorporation into crypt cells, regulating transcription of genes such as TGF-β1 In the fetus, the plasma membrane LfR is at the highest abundance in the small intestine, and the receptor gene is tightly controlled at multiple levels. Aspecific microRNA, miR-584, is involved in the posttranscriptional regulation of LfR, and in the human LfR DNA promoter, 2 Sp1 binding sites have been characterized functionally. Finally, cell proliferation and global gene expression reveal that native bovine Lf can perform biological activities similar to those exerted by human Lf in postnatal small intestinal development. Key words: lactoferrin, small intestine, lactoferrin receptor, development. Le modelage post-natal de l'epithelium intestinal a des impacts a long terme sur le developpement sain des nourrissons, et depend largement de la composition nutritive de la diete. La lactoferrine (Lf) se trouve parmi les differents facteurs trophiques du lait humain qui facilitent l'adaptation intestinale du nourrisson. L'hydrolyse de la Lf est minimale au pH qui prevaut en periode postprandiale chez le nourrisson, faisant en sorte que la Lf possede un meilleur potentiel biologique chez les bebes que chez les adultes. La Lf stimule de maniere bidirectionnelle la proliferation et la differenciation des cellules epitheliales du petit intestin de facon dependante de la concentration, et affecte ainsi le poids et la longueur du petit intestin, de meme que l'expression d'enzymes digestives epitheliales. Un recepteur de Lf de 105 kDa (LfR) intervient specifiquement dans la captation de Lf par les enterocytes et les cellules des cryptes. Sur le plan mecanistique, le complexe constitue de la Lf et du LfR est internalise par endocytose dependante de la clathrine; tant l'apo-Lf, sans fer, que la holo-Lf saturee en fer activent la voie PI3K/Akt alors que seule l'apo-Lf declenche la signalisation de ERK1/2. La Lf penetre dans le noyau ou elle peut stimuler l'incorporation de thymidine dans les cellules des cryptes, regulant la transcription de genes comme celui du TGF-β1. Chez le foetus, le LfR de la membrane plasmique est tres abondant dans le petit intestin, et le gene codant le recepteur est etroitement controle a plusieurs niveaux : un microARN specifique, miR-584, est implique dans la regulation post-transcriptionnelle du LfR, et deux sites de liaison de Sp1 ont ete caracterises fonctionnellement dans le promoteur du LfR humain. Finalement, la proliferation cellulaire et l'expression genique globale revelent que la Lf bovine native peut exercer des effets biologiques similaires a ceux de la Lf humaine lors du developpement post-natal du petit intestin. Mots-cles : lactoferrine, petit intestin, recepteur de la lactoferrine, developpement., Small intestinal growth during early life The early postnatal period is a critical window for the human infant to intensively establish small intestinal hierarchical structure and versatile functionality, ranging from [...]

Lactoferrin (Lf) is an abundantly expressed protein in human milk. Lactoferrin exhibits several important biological functions, and its expression is regulated by multiple environmental factors. Cellular endogenous factors, however, have not been extensively studied with regard to lactoferrin gene expression. In this study, we showed that lactoferrin gene expression and function are directly targeted by miR-214 in HC11 and MCF7 cells. In the lactoferrin mRNA 3' untranslated region (UTR) of human, mouse, rat, pig, bovine, camel, and goat species, there is a conserved region that perfectly matches the seed region of miR-214. Transfection of miR-214 mimic in HEK293 cells dose-dependently inhibited the activity of pGL3-control vector containing lactoferrin mRNA 3'UTR downstream of the luciferase gene. In HC11 cells, miR214 overexpression inhibited the induction of lactoferrin expression by [beta]-estradiol (E2) and dexamethasone-prolactin- insulin (DPI). Furthermore, in MCF7 cells, overexpression of miR-214 markedly decreased lactoferrin expression (P < 0.05), and inhibition of endogenous miR-214 expression increased lactoferrin expression and cellular apoptotic activities (P < 0.05). In summary, our data showed that miR-214 is directly involved in lactoferrin expression and lactoferrin mediated cancer susceptibility (proapoptotic activities) in mammary epithelial cells. J. Nutr. 140: 1552-1556, 2010. doi: 10.3945/jn.110.124289.

Diadegma semiclausum is an important parasitoid wasp and widely used in the biological control of the diamondback moth, Plutella xylostella, one of the most destructive pests of cruciferous plants. Insect olfactory system is critical in guiding behaviors including feeding, mating, and oviposition, in which odorant binding proteins (OBPs) and odorant receptors (ORs) are two key components. However, limited attention has been paid to D. semiclausum olfactory genes. In this study, a transcriptome sequencing was performed on the RNA samples extracted from D. semiclausum male and female adult antennae. A total of 17 putative OBP and 67 OR genes were annotated and further compared to OBPs and ORs from P. xylostella, and other hemipteran parasitoid species. The expression patterns of D. semiclausum OBPs between male and female antennae were examined using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR. Six OBPs (DsemOBP 6, 7, 8, 9, 10, and 14) demonstrated significantly higher expression levels in females than in males, which may assist in female D. semiclausum host-seeking and oviposition behaviors. This study advances our understanding of the olfactory system of D. semiclausum at the molecular level and paves the way for future functional studies aiming at increasing the efficacy to control P. xylostella by using D. semiclausum. [ABSTRACT FROM AUTHOR]

Sensory neuron membrane proteins (SNMPs) play a critical role in insect chemosensory system. Previously, three SNMPs were identified, characterized and functionally investigated in a lepidopteran model insect, Bombyx mori. However, whether these results are consistent across other lepidopteran species are unknown. Here genome and transcriptome data analysis, expression profiling, quantitative real‐time PCR (qRT‐PCR) and the yeast hybridization system were utilized to examine snmp genes of Helicoverpa armigera, one of the most destructive lepidopteran pests in cropping areas. In silico expression and qRT‐PCR analyses showed that, just as the B. mori snmp genes, H. armigera snmp1 (Harmsnmp1) is specifically expressed in adult antennae. Harmsnmp2 is broadly expressed in multiple tissues including adult antennae, tarsi, larval antennae and mouthparts. Harmsnmp3 is specifically expressed in larval midguts. Further RNAseq analysis suggested that the expression levels of Harmsnmp2 and Harmsnmp3 differed significantly depending on the plant species on which the larvae fed, indicating they may be involved in plant‐feeding behaviours. Yeast hybridization results revealed a protein–protein interaction between HarmSNMP1 and the sex pheromone receptor, HarmOR13. This study demonstrated that SNMPs may share same functions and mechanisms in different lepidopteran species, which improved our understanding of insect snmp genes and their functions in lepidopterans. [ABSTRACT FROM AUTHOR]