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Animals : An Open Access Journal From... Oct 2022In teleost, as in other vertebrates, stress affects reproduction. A key component of the stress response is the pituitary secretion of the adrenocorticotropic hormone...
In teleost, as in other vertebrates, stress affects reproduction. A key component of the stress response is the pituitary secretion of the adrenocorticotropic hormone (ACTH), which binds to the melanocortin 2 receptor (MC2R) in the adrenal glands and activates cortisol biosynthesis. In zebrafish, Mc2r was identified in male and female gonads, while ACTH has been shown to have a physiological role in modulating reproductive activity. In this study, the hypothesis that other melanocortins may also affect how the zebrafish gonadal function is explored, specifically steroid biosynthesis, given the presence of members of the melanocortin signaling system in zebrafish gonads. Using cell culture, expression analysis, and cellular localization of gene expression, our new observations demonstrated that melanocortin receptors, accessory proteins, antagonists, and agonists are expressed in both the ovary and testis of zebrafish ( = 4 each sex). Moreover, melanocortin peptides modulate both basal and gonadotropin-stimulated steroid release from zebrafish gonads ( = 15 for males and = 50 for females). In situ hybridization in ovaries ( = 3) of zebrafish showed and in follicular cells and adjacent to cortical alveoli in the ooplasm of previtellogenic and vitellogenic oocytes. In zebrafish testes ( = 3), and were detected exclusively in germ cells, specifically in spermatogonia and spermatocytes. Our results suggest that melanocortins are, directly or indirectly, involved in the endocrine control of vitellogenesis in females, through modulation of estradiol synthesis via autocrine or paracrine actions in zebrafish ovaries. Adult zebrafish testes were sensitive to low doses of ACTH, eliciting testosterone production, which indicates a potential role of this peptide as a paracrine regulator of testicular function.
PubMed: 36290123
DOI: 10.3390/ani12202737 -
Parasites & Vectors Oct 2022The amino acid transporter protein cationic amino acid transporter 1 (CAT1) is part of the nutrient sensor in the fat body of mosquitoes. A member of the SLC7 family of...
BACKGROUND
The amino acid transporter protein cationic amino acid transporter 1 (CAT1) is part of the nutrient sensor in the fat body of mosquitoes. A member of the SLC7 family of cationic amino acid transporters, it is paramount for the detection of elevated amino acid levels in the mosquito hemolymph after a blood meal and the subsequent changes in gene expression in the fat body.
METHODS
We performed a re-annotation of Aedes aegypti cationic amino acid transporters (CATs) and selected the C-terminal tail of CAT1 to perform a yeast two-hybrid screen to identify putative interactors of this protein. One interesting interacting protein we identified was general control nonderepressible 1 (GCN1). We determined the expression pattern of GCN1 in several adult organs and structures using qRT-PCR and western blots. Finally, we knocked down GCN1 using double-stranded RNA and identified changes in downstream signaling intermediates and the effects of knockdown on vitellogenesis and fecundity.
RESULTS
In a screen for Ae. aegypti CAT1-interacting proteins we identified GCN1 as a putative interactor. GCN1 is highly expressed in the ovaries and fat body of the mosquito. We provide evidence that eukaryotic translation initiation factor 2 subunit alpha (eIF2α) phosphorylation changed during vitellogenesis and that RNA interference knockdown of GCN1 in whole mosquitoes reduced egg clutch sizes of treated mosquitoes relative to controls.
CONCLUSIONS
Aedes aegypti CAT1 and GCN1 are likely interacting partners and GCN1 is likely necessary for proper egg development. Our data suggest that GCN1 is part of a nutrient sensor mechanism in various mosquito tissues involved in vitellogenesis.
Topics: Animals; Aedes; Cationic Amino Acid Transporter 1; RNA, Double-Stranded; Prokaryotic Initiation Factor-2; Saccharomyces cerevisiae; Amino Acid Transport Systems, Basic; Amino Acids; Fertility
PubMed: 36271393
DOI: 10.1186/s13071-022-05461-x -
General and Comparative Endocrinology Jan 2023The vitellogenin is composed by polypeptides that are precursors of egg yolk proteins that provides embryo and larvae nutrition. The mRNA encoding for vitellogenin Ab...
The vitellogenin is composed by polypeptides that are precursors of egg yolk proteins that provides embryo and larvae nutrition. The mRNA encoding for vitellogenin Ab (Vtg-Ab; 4,536 bp long and 1,512 amino acids) were obtained by RNA-Seq library sequencing of pirarucu gonads. The Vtg-Ab sequences had high homology with Vtgs of other three teleosts species of the order Osteoglossiformes. The transcript of ovarian Vtg was identified based on structural criteria, and so we classify the Vtg of pirarucu as Vtg-Ab due to the truncated or shortened phosvitin (N-terminal end) and phosvitinless domain (C-terminal end). The Vtg-Ab of pirarucu present two major deletions with 133 amino acids in the Lipovitellin I domain and 89 amino acids in the truncated or shortened Phosvitin domain, both located in the N-terminal end region. The three-dimensional (3-D) structure Vtg-Ab protein shows the presence of a typical 4α-helices bundle protein that runs in anti-parallel. In general, the characterization of Vtg-Ab may be the useful elucidation of the hormonal regulation of vitellogenesis and improve the production of pirarucu for broodstock management in aquaculture and preparation of Vtg antibody production (species-specific) for sex identification.
Topics: Animals; Vitellogenins; Phosvitin; Amino Acid Sequence; Fishes; Amino Acids
PubMed: 36244430
DOI: 10.1016/j.ygcen.2022.114143 -
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 -
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 -
Archives of Insect Biochemistry and... Jan 2023Methoprene-tolerant (Met) as an intracellular receptor of juvenile hormone (JH) and the Krüppel-homolog 1 (Kr-h1) as a JH-inducible transcription factor had been proved...
Involvement of Methoprene-tolerant and Krüppel homolog 1 in juvenile hormone-mediated vitellogenesis of female Liposcelis entomophila (End.) (Psocoptera: Liposcelididae).
Methoprene-tolerant (Met) as an intracellular receptor of juvenile hormone (JH) and the Krüppel-homolog 1 (Kr-h1) as a JH-inducible transcription factor had been proved to contribute to insect reproduction. Their functions vary in different insect orders, however, they are not clear in Psocoptera. In this study, LeMet and LeKr-h1 were identified and their roles in vitellogenesis and ovarian development were investigated in Liposcelis entomophila (Enderlein). Treatment with exogenous JH III significantly induced the expression of LeKr-h1, LeVg, and LeVgR. Furthermore, silencing LeMet and LeKr-h1 remarkably reduced the transcription of LeVg and LeVgR, disrupted the production of Vg in fat body and the uptake of Vg by oocytes, and ultimately led to a decline in fecundity. The results indicated that the JH signaling pathway was essential to the reproductive process of this species. Interestingly, knockdown of LeMet or LeKr-h1 also resulted in fluctuations in the expression of FoxO, indicating the complex regulatory interactions between different hormone factors. Besides, knockdown of both LeMet and LeKr-h1 significantly increased L. entomophila mortality. Our study provides initial insight into the roles of JH signaling in the female reproduction of psocids and provided evidence that RNAi-mediated knockdown of Met or Kr-h1 is a potential pest control strategy.
Topics: Female; Animals; Juvenile Hormones; Methoprene; Vitellogenesis; Transcription Factors; RNA Interference; Neoptera; Insect Proteins
PubMed: 36193599
DOI: 10.1002/arch.21973 -
General and Comparative Endocrinology Jan 2023Eyestalk-derived neuropeptides, primarily the crustacean hyperglycemic hormone (CHH) neuropeptide family, regulate vitellogenesis in decapod crustaceans. The red...
Eyestalk-derived neuropeptides, primarily the crustacean hyperglycemic hormone (CHH) neuropeptide family, regulate vitellogenesis in decapod crustaceans. The red deep-sea crab, Chaceon quinquedens, a cold-water species inhabiting depths between 200 and 1800 m, has supported a small fishery, mainly harvesting adult males in the eastern US for over 40 years. This study aimed to understand the role of eyestalk-neuropeptides in vitellogenesis in C. quinquedens with an extended intermolt stage. Chromatography shows two CHH and one MIH peak in the sinus gland, with a CHH2 peak area four times larger than CHH1. The cDNA sequence of MIH and CHH of C. quinquedens is isolated from the eyestalk ganglia, and the qPCR assay shows MIH is significantly higher only at ovarian stages 3 than 4 and 5. However, MIH transcript and its neuropeptides do differ between stages 1 and 3. While CHH transcripts remain constant, its neuropeptide levels are higher at stages 3 than 1. Additionally, transcriptomic analysis of the de novo eyestalk ganglia assembly at ovarian stages 1 and 3 found 28 eyestalk neuropeptides. A GIH/VIH or GSH/VSH belonging to the CHH family is absent in the transcriptome. Transcripts per million (TPM) values of ten neuropeptides increase by 1.3 to 2.0-fold at stage 3 compared to stage 1: twofold for Bursicon α, followed by CHH, AKH/corazonin-like, Pyrokinin, CCAP, Glycoprotein B, PDH1, and IDLSRF-like peptide, and 1.3-fold of allatostatin A and short NP-F. WXXXRamide, the only downregulated neuropeptide, decreases TPM by ∼ 2-fold at stage 3, compared to stage 1. Interestingly, neuroparsin with the highest TPM values remains the same in stages 1 and 3. The mandibular organ-inhibiting hormone is not found in de novo assembly. We report that CHH, MIH, and eight other neuropeptides may play a role in vitellogenesis in this species.
Topics: Animals; Male; Female; Brachyura; Invertebrate Hormones; Arthropod Proteins; Neuropeptides; Ganglia; DNA, Complementary; Transcriptome
PubMed: 36152768
DOI: 10.1016/j.ygcen.2022.114128 -
Frontiers in Genetics 2022The mud crab, , has abundant nutrients in its edible parts, ovary, hepatopancreas, and muscle during the ovarian maturation stage. The ovary of can re-mature after...
Insight of vitellogenesis patterns: A comparative analysis of the differences between the primary and secondary vitellogenesis period in the ovary, hepatopancreas, and muscle of mud crab, .
The mud crab, , has abundant nutrients in its edible parts, ovary, hepatopancreas, and muscle during the ovarian maturation stage. The ovary of can re-mature after spawning during the secondary ovarian maturation period. We aimed to analyze the characteristics of the first vitellogenesis period (FVP) and second vitellogenesis period (SVP) of during ovarian maturation to understand the differences in vitellogenesis patterns between the first and second ovarian maturation periods. Accordingly, the gonadosomatic index (GSI) and hepatopancreatic index (HSI), the external and histological characteristics of the ovary and hepatopancreas, the (vitellogenin, Vg) expression levels in the hepatopancreas and ovary, and the dynamics of the biochemical components in the ovary, hepatopancreas, and muscle were determined. Based on the results, the GSI was significantly positively correlated with HSI during the FVP and significantly negatively correlated with HSI from stage Ⅳ to stage Ⅴ of the SVP. A significant difference was found between the FVP and SVP in the hepatopancreas. Notably, the hepatopancreas displayed a gradual degeneration trend during the SVP. The expression level of was significantly higher in the hepatopancreas than that in the ovary during the FVP and SVP. Seventeen amino acids were detected in the hepatopancreas, ovary, and muscle during the FVP and SVP, with glutamate as the predominant amino acid. During the FVP and SVP, the C16:0 and C18:1n9c were the dominant fatty acids in the hepatopancreas and ovary, the MUFA gradually increased in the ovary and hepatopancreas, and a significant difference was found in the dynamic trend of the HUFA and SFA contents from stage Ⅳ to stage Ⅴ between the FVP and SVP. These findings indicate that the ovary can re-mature after spawning in and can maintain the status of the first ovarian maturation; however, the hepatopancreas gradually degenerate during the SVP.
PubMed: 36105103
DOI: 10.3389/fgene.2022.965070 -
Current Biology : CB Nov 2022The emergence of systemic nutrient transport was a key challenge during animal evolution, yet it is poorly understood. Circulatory systems distribute nutrients in many...
The emergence of systemic nutrient transport was a key challenge during animal evolution, yet it is poorly understood. Circulatory systems distribute nutrients in many bilaterians (e.g., vertebrates and arthropods) but are absent in non-bilaterians (e.g., cnidarians and sponges), where nutrient absorption and transport remain little explored at molecular and cellular levels. Vitellogenesis, the accumulation of egg yolk, necessitates high nutrient influx into oocytes and is present throughout animal phyla and therefore represents a well-suited paradigm to study nutrient transport evolution. With that aim, we investigated dietary nutrient transport to the oocytes in the cnidarian Nematostella vectensis (Anthozoa). Using a combination of fluorescent bead labeling and marker gene expression, we found that phagocytosis, micropinocytosis, and intracellular digestion of food components occur within the gonad epithelium. Pulse-chase experiments further show that labelled fatty acids rapidly translocate from the gonad epithelium through the extracellular matrix (ECM) into oocytes. Expression of conserved lipid transport proteins vitellogenin (vtg) and apolipoprotein-B (apoB) and colocalization of labeled fatty acids with a fluorescently tagged ApoB protein further support the lipid-shuttling role of the gonad epithelium. Complementary oocyte expression of very low-density lipoprotein receptor (vldlr) orthologs, which mediate endocytosis of bilaterian ApoB- and Vtg-lipoproteins, supports that this evolutionarily conserved ligand/receptor pair underlies lipid transport during sea anemone vitellogenesis. In addition, we identified lipid- and ApoB-rich cells with potential lipid transport roles in the ECM. Altogether, our work supports a long-standing hypothesis that an ECM-based lipid transport system predated the cnidarian-bilaterian split and provided a basis for the evolution of bilaterian circulatory systems.
Topics: Animals; Vitellogenesis; Sea Anemones; Nutrients; Apolipoproteins B; Fatty Acids; Lipids
PubMed: 36084649
DOI: 10.1016/j.cub.2022.08.039 -
Conservation Physiology 2021Understanding the timing of vitellogenesis is essential for identifying threats to the reproductive success of endangered oviparous vertebrate species, such as sea...
Understanding the timing of vitellogenesis is essential for identifying threats to the reproductive success of endangered oviparous vertebrate species, such as sea turtles. We measured concentrations of testosterone (T) and vitellogenin (VTG) in green sea turtles () nesting at Tortuguero, Costa Rica, as biomarkers of ovarian development. Testosterone concentration increased from the first to second month and VTG concentration increased at the third week of sampling. These results show that Tortuguero green sea turtles were still producing both biomarkers early into the nesting season. VTG concentration was negatively correlated with female weight, suggesting that larger females start nesting earlier at Tortuguero and that we may have sampled larger females further into their reproductive cycle.
PubMed: 36082195
DOI: 10.1093/conphys/coab072