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PloS One 2020The life cycle of European eel (Anguilla anguilla), a catadromous species, is complex and enigmatic. In nature, during the silvering process prior to their long spawning...
The life cycle of European eel (Anguilla anguilla), a catadromous species, is complex and enigmatic. In nature, during the silvering process prior to their long spawning migration, reproductive development is arrested, and they cease feeding. In studies of reproduction using hormonal induction, eels are equivalently not feed. Therefore, in female eels that undergo vitellogenesis, the liver plays different, essential roles being involved both in vitellogenins synthesis and in reallocating resources for the maintenance of vital functions, performing the transoceanic reproductive migration and completing reproductive development. The present work aimed at unravelling the major transcriptomic changes that occur in the liver during induced vitellogenesis in female eels. mRNA-Seq data from 16 animals (eight before induced vitellogenesis and eight after nine weeks of hormonal treatment) were generated and differential expression analysis was performed comparing the two groups. This analysis detected 1,328 upregulated and 1,490 downregulated transcripts. Overrepresentation analysis of the upregulated genes included biological processes related to biosynthesis, response to estrogens, mitochondrial activity and localization, while downregulated genes were enriched in processes related to morphogenesis and development of several organs and tissues, including liver and immune system. Among key genes, the upregulated ones included vitellogenin genes (VTG1 and VTG2) that are central in vitellogenesis, together with ESR1 and two novel genes not previously investigated in European eel (LMAN1 and NUPR1), which have been linked with reproduction in other species. Moreover, several upregulated genes, such as CYC1, ELOVL5, KARS and ACSS1, are involved in the management of the effect of fasting and NOTCH, VEGFA and NCOR are linked with development, autophagy and liver maintenance in other species. These results increase the understanding of the molecular changes that occur in the liver during vitellogenesis in this complex and distinctive fish species, bringing new insights on European eel reproduction and broodstock management.
Topics: Anguilla; Animals; Female; Liver; RNA-Seq; Reproduction; Transcriptome; Vitellogenesis
PubMed: 32790680
DOI: 10.1371/journal.pone.0236438 -
Insect Biochemistry and Molecular... Jun 2021Triatomines are vectors of Chagas disease and important model organisms in insect physiology. "Kissing bugs" are obligatory hematophagous insects. A blood meal is...
Triatomines are vectors of Chagas disease and important model organisms in insect physiology. "Kissing bugs" are obligatory hematophagous insects. A blood meal is required to successfully complete oogenesis, a process primarily controlled by juvenile hormone (JH). We used Dipetalogaster maxima as an experimental model to further understand the roles of JH in the regulation of vitellogenesis and oogenesis. A particular focus was set on the role of JH controlling lipid and protein recruitment by the oocytes. The hemolymph titer of JH III skipped bisepoxide increased after a blood meal. Following a blood meal there were increased levels of mRNAs in the fat body for the yolk protein precursors, vitellogenin (Vg) and lipophorin (Lp), as well as of their protein products in the hemolymph; mRNAs of the Vg and Lp receptors (VgR and LpR) were concomitantly up-regulated in the ovaries. Topical administration of JH induced the expression of Lp/LpR and Vg/VgR genes, and prompted the uptake of Lp and Vg in pre-vitellogenic females. Knockdown of the expression of LpR by RNA interference in fed females did not impair the Lp-mediated lipid transfer to oocytes, suggesting that the bulk of lipid acquisition by oocytes occurred by other pathways rather than by the endocytic Lp/LpR pathway. In conclusion, our results strongly suggest that JH signaling is critical for lipid storage in oocytes, by regulating Vg and Lp gene expression in the fat body as well as by modulating the expression of LpR and VgR genes in ovaries.
Topics: Animals; Female; Insect Proteins; Insecta; Juvenile Hormones; Lipid Metabolism; Lipoproteins; Oocytes; Oogenesis; Ovary; RNA Interference; Receptors, Cytoplasmic and Nuclear; Signal Transduction; Triatominae; Vitellogenesis; Vitellogenins
PubMed: 33212190
DOI: 10.1016/j.ibmb.2020.103499 -
Frontiers in Physiology 2017Heme and iron are essential molecules for many physiological processes and yet have the ability to cause oxidative damage such as lipid peroxidation, protein... (Review)
Review
Heme and iron are essential molecules for many physiological processes and yet have the ability to cause oxidative damage such as lipid peroxidation, protein degradation, and ultimately cell death if not controlled. Blood-sucking arthropods have evolved diverse methods to protect themselves against iron/heme-related damage, as the act of bloodfeeding itself is high risk, high reward process. Protective mechanisms in medically important arthropods include the midgut peritrophic matrix in mosquitoes, heme aggregation into the crystalline structure hemozoin in kissing bugs and hemosomes in ticks. Once heme and iron pass these protective mechanisms they are presumed to enter the midgut epithelial cells via membrane-bound transporters, though relatively few iron or heme transporters have been identified in bloodsucking arthropods. Upon iron entry into midgut epithelial cells, ferritin serves as the universal storage protein and transport for dietary iron in many organisms including arthropods. In addition to its role as a nutrient, heme is also an important signaling molecule in the midgut epithelial cells for many physiological processes including vitellogenesis. This review article will summarize recent advancements in heme/iron uptake, detoxification and exportation in bloodfeeding arthropods. While initial strides have been made at ironing out the role of dietary iron and heme in arthropods, much still remains to be discovered as these molecules may serve as novel targets for the control of many arthropod pests.
PubMed: 29387018
DOI: 10.3389/fphys.2017.01134 -
Veterinary Parasitology Nov 2021Rhipicephalus microplus is an important cattle tick, and resistant strains to synthetic compounds have been widespread. The combined effects of different essential oil...
Effects of acaricidal essential oils from Lippia sidoides and Lippia gracilis and their main components on vitellogenesis in Rhipicephalus microplus (Canestrini, 1888) (Acari: Ixodidae).
Rhipicephalus microplus is an important cattle tick, and resistant strains to synthetic compounds have been widespread. The combined effects of different essential oil compounds enhance biological activity and reduce selection for the development of target organism resistance. Essential oils of two different genotypes of each of Lippia sidoides and Lippia gracilis and their main components, the isomers thymol and carvacrol, have acted as acaricides against R. microplus. Little is known about the effects of the essential oils of L. sidoides and L. gracilis and thymol and carvacrol on the morphophysiology of R. microplus ovaries. This study aimed to identify the morphological changes in the ovaries of R. microplus females treated with essential oils from two different genotypes of each of L. sidoides (102 and 103) and L. gracilis (106 and 201) and the terpenes thymol and carvacrol through histological techniques. The LC and LC of essential oils and thymol and carvacrol were used for Adult Immersion Test (AIT) with groups of five fully engorged females of R. microplus. A negative control (DMSO 3% solution) was performed. Seven days after the AIT, the ticks were dissected to collect ovaries and their histologic analysis. Only the group treated with the essential oil of L. gracilis genotype 106 at the LC had no change compared with the control. The other groups showed the following changes in oocytes I to V: vacuolation, chorion deformation, disorganization of yolk granules, and irregularities at the cell periphery, causing incomplete process of vitellogenesis. Thus, the essential oils tested in this study may be potent products for the control of cattle ticks and thereby preventing further life cycles.
Topics: Acaricides; Animals; Ixodidae; Larva; Lippia; Oils, Volatile; Plant Oils; Rhipicephalus; Vitellogenesis
PubMed: 34583144
DOI: 10.1016/j.vetpar.2021.109584 -
Journal of Fish Biology Feb 2022Providing a non-invasive procedure to track fish maturity remains a priority in broodstocks' management. In the present study, the main goal was to assess reproduction... (Comparative Study)
Comparative Study
Comparative study on accuracy of mucosal estradiol-17β, testosterone and 11-ketotestosterone, for maturity, and cutaneous vitellogenin gene expression in goldfish (Carassius auratus).
Providing a non-invasive procedure to track fish maturity remains a priority in broodstocks' management. In the present study, the main goal was to assess reproduction status by measuring sex steroids and vitellogenin (VTG) in the skin mucosa, as a non-invasive method. For this purpose, the present study compared the levels of estradiol-17β (E ), testosterone (T), 11-ketotestosterone (11-KT), VTG and calcium (Ca) in skin mucosa and blood plasma of goldfish (Carassius auratus). Skin mucosal and blood samples were collected, as well as gonad tissues, from goldfish, as a seasonal spawner. Histological analysis confirmed the gender and maturity status from females' ovaries (as primary-growth, cortical-alveoli, initial and late-vitellogenesis) and males' testes (as spermatogenesis and spermiation). Furthermore, vitellogenin (vtg) expression was observed in skin, liver and gonads. The results indicate that mucosal E concentrations were significantly higher during initial and late vitellogenesis than the other stages. Mucosal 11-KT concentrations significantly increased at spermiation (P < 0.05). E /T and 11-KT/E ratios significantly increased at early vitellogenesis and spermatogenesis, respectively (P < 0.05). Females' mucosal VTG levels were significantly fluctuated according to the maturity stage. Ca showed a similar trend, but Ca was more accurate for sex identification than the VTG. Although mucus showed high levels of VTG, ovarian vtg expression was strongest while liver and skin had the similar results. These results show that measuring the mucosal androgens could be considered as an accurate, non-invasive method to monitor fish maturity.
Topics: Animals; Estradiol; Female; Gene Expression; Goldfish; Male; Mucous Membrane; Testosterone; Vitellogenins
PubMed: 34822181
DOI: 10.1111/jfb.14963 -
Journal of Fish Biology Jan 2021A wide range of classification schemes has been developed to describe reproductive development and stages in teleosts. These have been rationalised for clarity in recent... (Review)
Review
A wide range of classification schemes has been developed to describe reproductive development and stages in teleosts. These have been rationalised for clarity in recent years by Brown-Peterson et al. (Marine and Coastal Fisheries, 2011, 3, 52-70) and the WKASMSF (ICES, Report of the workshop for advancing sexual maturity staging in fish (WKASMSF), 2018) working groups. These have largely benchmarked classification schemes with examples from seawater fishes but have not been routinely applied to freshwater species. In addition, classification schemes developed to assess maturation of fish ovaries are either macroscopic and can be used in the field or histological for laboratory-based studies, and the two have rarely been coupled in the same classification scale or study. The present study reviews published maturation classifications for application to a freshwater teleost, ruffe Gymnocephalus cernuus L., sampled monthly over three annual cycles in Loch Lomond at locations in the extreme north and south ends of the loch. The gonado-somatic index and size frequency distribution of oocytes were used to verify the annual reproductive cycle and spawning of several egg batches. The study showed that a paired modified Percid scale (Treasurer & Holliday, Journal of Fish Biology, 1981, 18, 359-376) and the Rinchard scale (Rinchard & Kestemont, Journal of Fish Biology, 1996, 49, 883-894) gave an improved macroscopic and histological description of maturation compared with and benchmarked against previous ovarian developmental classifications for G. cernuus. The attributes of these various classifications are benchmarked and compared with the Brown-Peterson and WKMATCH scales, and the merits of these new notations are examined.
Topics: Animals; Benchmarking; Female; Fresh Water; Lakes; Perches; Reproduction
PubMed: 33015840
DOI: 10.1111/jfb.14575 -
Proceedings of the National Academy of... Jun 2022The primary insect steroid hormone ecdysone requires a membrane transporter to enter its target cells. Although an organic anion-transporting polypeptide (OATP) named...
The primary insect steroid hormone ecdysone requires a membrane transporter to enter its target cells. Although an organic anion-transporting polypeptide (OATP) named Ecdysone Importer (EcI) serves this role in the fruit fly and most likely in other arthropod species, this highly conserved transporter is apparently missing in mosquitoes. Here we report three additional OATPs that facilitate cellular incorporation of ecdysone in and the yellow fever mosquito . These additional ecdysone importers (EcI-2, -3, and -4) are dispensable for development and reproduction in , consistent with the predominant role of EcI. In contrast, in , EcI-2 is indispensable for ecdysone-mediated development, whereas EcI-4 is critical for vitellogenesis induced by ecdysone in adult females. Altogether, our results indicate unique and essential functions of these additional ecdysone importers in mosquito development and reproduction, making them attractive molecular targets for species- and stage-specific control of ecdysone signaling in mosquitoes.
Topics: Aedes; Animals; Drosophila; Drosophila melanogaster; Ecdysone; Female; Insect Proteins; Organic Anion Transporters; Vitellogenesis
PubMed: 35696563
DOI: 10.1073/pnas.2202932119 -
Animal Reproduction 2023Carotenoids are determinants of reproductive fitness and egg quality. Here we studied the accumulation of astaxanthin (AX), canthaxanthin (CA) zeaxanthin (ZX), lutein...
Carotenoids are determinants of reproductive fitness and egg quality. Here we studied the accumulation of astaxanthin (AX), canthaxanthin (CA) zeaxanthin (ZX), lutein (LU), retinol (RX) and dehydroretinol (DR) during vitellogenesis comparing previtellogenic and vitellogenic pikeperch () eggs (n = 5 each), as well as selected tissues (liver, fat and muscles) in first süawning females (1176-1450 g). Futhermore, we compared egg batches with high (88-99% hatching rate, n = 5) or low (40-67% hatching rate, n= 5) egg quality. Vitellogenic follicles revealed higher concentrations of DR, RX, ZX and LU compared to previtellogenic follicles. Neither CA nor AX was detectable. In parallel, DR and RX were mobilized in the liver. In adipose and muscle tissue, comparing previtellogenic and vitellogenic females, no significant differences in carotenoid/retinoid content were observed. In high quality egg batches, both DR and RX were increased. LU was lower in high quality than in low quality eggs. In a conclusion, the amount of retinoids seems suboptimal in low quality egg batches and increased DR and RX are desirable in pikeperch. Since hypervitaminosis of retinoids can be problematic though, supplementation of the food with carotenoids, which can serve as precursors for retinoids, has to be carried out carefully.
PubMed: 37228385
DOI: 10.1590/1984-3143-AR2022-0103 -
BMC Genomics Sep 2017Oogenesis in the domestic silkworm (Bombyx mori) is a complex process involving previtellogenesis, vitellogenesis and choriogenesis. During this process, follicles show...
BACKGROUND
Oogenesis in the domestic silkworm (Bombyx mori) is a complex process involving previtellogenesis, vitellogenesis and choriogenesis. During this process, follicles show drastic morphological and physiological changes. However, the genome-wide regulatory profiles of gene expression during oogenesis remain to be determined.
RESULTS
In this study, we obtained time-series transcriptome data and used these data to reveal the dynamic landscape of gene regulation during oogenesis. A total of 1932 genes were identified to be differentially expressed among different stages, most of which occurred during the transition from late vitellogenesis to early choriogenesis. Using weighted gene co-expression network analysis, we identified six stage-specific gene modules that correspond to multiple regulatory pathways. Strikingly, the biosynthesis pathway of the molting hormone 20-hydroxyecdysone (20E) was enriched in one of the modules. Further analysis showed that the ecdysteroid 20-hydroxylase gene (CYP314A1) of steroidgenesis genes was mainly expressed in previtellogenesis and early vitellogenesis. However, the 20E-inactivated genes, particularly the ecdysteroid 26-hydroxylase encoding gene (Cyp18a1), were highly expressed in late vitellogenesis. These distinct expression patterns between 20E synthesis and catabolism-related genes might ensure the rapid decline of the hormone titer at the transition point from vitellogenesis to choriogenesis. In addition, we compared landscapes of gene regulation between silkworm (Lepidoptera) and fruit fly (Diptera) oogeneses. Our results show that there is some consensus in the modules of gene co-expression during oogenesis in these insects.
CONCLUSIONS
The data presented in this study provide new insights into the regulatory mechanisms underlying oogenesis in insects with polytrophic meroistic ovaries. The results also provide clues for further investigating the roles of epigenetic reconfiguration and circadian rhythm in insect oogenesis.
Topics: Animals; Bombyx; Drosophila melanogaster; Gene Expression Regulation, Developmental; High-Throughput Nucleotide Sequencing; Hormones; Oogenesis; Sequence Analysis, RNA
PubMed: 28893182
DOI: 10.1186/s12864-017-4123-6 -
Aging Cell Nov 2022Some of the most conspicuous aging phenotypes of C. elegans are related to post-reproductive production of vitellogenins (Vtg), which form yolk protein (YP) complexes...
Some of the most conspicuous aging phenotypes of C. elegans are related to post-reproductive production of vitellogenins (Vtg), which form yolk protein (YP) complexes after processing and lipid loading. Vtg/YP levels show huge increases with age, and inhibition of this extends lifespan, but how subcellular and organism-wide distribution of these proteins changes with age has not been systematically explored. Here, this has been done to understand how vitellogenesis promotes aging. The age-associated changes of intestinal vitellogenin vesicles (VVs), pseudocoelomic yolk patches (PYPs), and gonadal yolk organelles (YOs) have been characterized by immuno-electron microscopy. We find that from reproductive adult day 2 (AD 2) to post-reproductive AD 6 and AD 9, intestinal VVs expand from 0.2 to 3-4 μm in diameter or by >3000 times in volume, PYPs increase by >3 times in YP concentration and volume, while YOs in oocytes shrink slightly from 0.5 to 0.4 μm in diameter or by 49% in volume. In AD 6 and AD 9 worms, mislocalized YOs found in the hypodermis, uterine cells, and the somatic gonadal sheath can reach a size of 10 μm across in the former two tissues. This remarkable size increase of VVs and that of mislocalized YOs in post-reproductive worms are accompanied by extensive fusion between these Vtg/YP-containing vesicular structures in somatic cells. In contrast, no fusion is seen between YOs in oocytes. We propose that in addition to the continued production of Vtg, excessive fusion between VVs and mislocalized YOs in the soma worsen the aging pathologies seen in C. elegans.
Topics: Animals; Vitellogenins; Caenorhabditis elegans; Vitellogenesis; Egg Proteins; Oocytes
PubMed: 36199214
DOI: 10.1111/acel.13719