-
General and Comparative Endocrinology Jan 2023Marphysa madrasi is a commercially valuable maturation diet in crustacean aquaculture. This study presents the first detailed investigation of oogenesis in the...
Marphysa madrasi is a commercially valuable maturation diet in crustacean aquaculture. This study presents the first detailed investigation of oogenesis in the intertidal polychaete worm M. madrasi and reports the steroid profile during oocyte growth and development. Oogenesis is extraovarian type I, originating from coelomic epithelial cells, with four stages of development - primary growth, early vitellogenic, late vitellogenic, and maturation. The primary growth phase contains oogonial cells and previtellogenic oocyte clusters in the early, mid, and late stages of development form a dispersed ovary attached to blood vessels. The late previtellogenic oocytes detach from the ovary at the onset of vitellogenesis. The detached oocytes complete vitellogenesis and final maturation in the coelomic fluid as solitary free-floating cells without any connection with follicle cells. The worms display asynchronous reproduction with a heterogeneous population of developing oocytes. Steroid extracts from the polychaete homogenates in different stages of oogenesis were identified by HPLC and confirmed by LC-MS/MS. In M. madrasi, two vertebrate-type steroids, pregnenolone (P5) and 17α-hydroxyprogesterone (17-OHP) were detected and quantified. The P5 levels were low in immature worms but increased significantly by ∼ 8.3-fold in the previtellogenic stage and peaked during oocyte maturation. 17-OHP levels were low in immature worms but gradually increase as the oogenesis progress to the primary growth and early vitellogenic phase, with a significant increase (p < 0.001) during the late vitellogenic phase. Although an increase in the concentration of P5 and 17-OHP during vitellogenesis and maturation of oocytes points to a possible role in reproduction, the absence of other vertebrate-type steroids in the investigated polychaete signifies a plausible uptake of P5 and 17-OHP from the environment.
Topics: Animals; Female; Polychaeta; Chromatography, Liquid; Tandem Mass Spectrometry; Oogenesis; Vitellogenesis; Oocytes; Gonadal Steroid Hormones; Steroids
PubMed: 36037874
DOI: 10.1016/j.ygcen.2022.114118 -
General and Comparative Endocrinology May 2017Estrogen receptors (Er) play a critical role in vitellogenesis. Three ers (erα, erβ1 and erβ2) and vitellogenins (vtg-A, vtg-B and vtg-C) subtypes were isolated in...
Estrogen receptors (Er) play a critical role in vitellogenesis. Three ers (erα, erβ1 and erβ2) and vitellogenins (vtg-A, vtg-B and vtg-C) subtypes were isolated in various fish species, while the contribution of each Er to the regulation of vtgs expression was not analyzed in detail. Here, erα, erβ1 and erβ2 were cloned and all were found to be expressed in female liver in Scatophagus argus. During proteic vitellogenesis stage, erα was simultaneously up-regulated, while erβ1 and erβ2 were not, with three vtgs in female liver. The effects of 17β-estradiol (E) alone or combined with Er antagonists on ers, vtgs mRNA expressions and Vtg protein content in incubated male liver were examined by real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The expressions of erα, erβ1, vtgs mRNA and Vtg protein increased significantly after 24h incubation with E (0.1, 1 and 10μM), while Er nonselective antagonist ICI 182 780 (0.01, 0.1 and 1μM) significantly attenuated the up-regulation effects of E on ers, vtgs mRNA and Vtg protein in a dose-dependent manner. Erα selective antagonist Methyl-piperidinopyrazole (MPP) (0.01, 0.1 and 1μM) significantly attenuated the up-regulation effects of E on erα, vtg-B, vtg-C mRNA and Vtg protein, while promoted the expression of erβ1 and vtg-A. Erβ selective antagonist Cyclofenil (0.01, 0.1 and 1μM) attenuated the up-regulation effects of E on erβ1, erβ2, vtg-A, vtg-C mRNA and Vtg protein while promoted the expression of erα and vtg-B. Our results suggest that the regulation of Ers on different vtgs was divergent in S. argus.
Topics: Amino Acid Sequence; Animals; Cloning, Molecular; Enzyme-Linked Immunosorbent Assay; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Liver; Male; Perciformes; RNA, Messenger; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Sequence Homology, Amino Acid; Vitellogenesis; Vitellogenins
PubMed: 28322764
DOI: 10.1016/j.ygcen.2017.03.002 -
Marine Biotechnology (New York, N.Y.) Dec 2023Inadequate gonadal maturation and poor spawning performance increasingly threaten the sustainability of shrimp aquaculture. Unraveling the mechanisms regulating ovarian...
Inadequate gonadal maturation and poor spawning performance increasingly threaten the sustainability of shrimp aquaculture. Unraveling the mechanisms regulating ovarian development and maturation hence is critical to address industry challenges. Vitellogenin (Vtg), a precursor of yolk protein found in the hepatopancreas and ovary of shrimp, plays a key role in facilitating shrimp's oocyte maturation and embryonic development after oviposition. This study found that FpVtg was specifically expressed in F. penicillatus hepatopancreas and ovary. FpVtg was localized predominantly in the oocyte cytoplasm and distributed uniformly in the hepatopancreas tissue. Silencing FpVtg led to apoptosis in both hepatopancreas and ovary tissues. Furthermore, FpVtg depletion upregulated the expression of ovarian peritrophin 1, ovarian peritrophin 2, serine proteinase inhibitor 6, and juvenile hormone esterase-like carboxylesterase 1, while downregulated that of vitellogenin, delta-9 desaturase, and insulin-like receptor. KEGG pathway analysis implicated such as PI3K-AKT signaling, RNA transport, ECM-receptor interaction, hippo signaling, oocyte meiosis, and apoptosis were enriched and involved in ovarian development. These findings have provided insights into the FpVtg's reproductive role and the associated regulatory genes and pathways in F. penicillatus. This knowledge can contribute to establishing strategies to improve the breeding and aquaculture production of F. penicillatus by elucidating its vitellogenesis regulation in redtail prawn and other penaeid species. Further characterization of the implicated pathways and genes will clarify the intricacies underlying ovarian maturation.
Topics: Animals; Female; Ovary; Vitellogenins; RNA, Small Interfering; Phosphatidylinositol 3-Kinases; Penaeidae; Vitellogenesis
PubMed: 38010485
DOI: 10.1007/s10126-023-10269-6 -
General and Comparative Endocrinology Jan 2021Reproductive activity is closely related to the development and function of the brain and liver in teleosts, particularly in seasonal breeding teleosts. This study...
Identification and characteristics of insulin-like growth factor system in the brain, liver, and gonad during development of a seasonal breeding teleost, Pampus argenteus.
Reproductive activity is closely related to the development and function of the brain and liver in teleosts, particularly in seasonal breeding teleosts. This study measured the involvement of the insulin-like growth factor (IGF) system in controlling the reproduction of the silver pomfret Pampus argenteus, a seasonal breeding tropical to temperate commercial fish. We cloned and characterized the cDNAs of igfs (igf2 and igf3) and igfrs (igf1ra, igf1rb, and igf2r) and examined their transcript levels in relation to seasonal reproduction. Phylogenetic analyses revealed that two types of IGFs (IGF-1 and IGF-2) and three types of IGFRs (IGF1RA, IGF1RB, and IGF2R) of the silver pomfret were clustered with those of teleosts; however, IGF-3 was a transmembrane protein different with the IGF-3 of other teleosts. The expression of IGF-3 was gonad-specific in the silver pomfret. The transcript levels of igf1 in the female brain were the highest, and the levels of igfrs in both sexes' brains increased during gametogenesis. Meanwhile, igfs and igfrs maintained high transcript levels in both sexes' liver and gonad during vitellogenesis and spermatogonia proliferation. We concluded that the development and activities of brain, liver, and gonad were related to the IGF system (IGFs and IGFRs). And the IGFs were mainly expressed in the liver. Nevertheless, gonadal development, especially vitellogenesis and spermatogonia proliferation, were related with IGFs in this species.
Topics: Amino Acid Sequence; Animals; Body Weight; Brain; Breeding; DNA, Complementary; Female; Gene Expression Regulation, Developmental; Gonads; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Liver; Male; Perciformes; Phylogeny; RNA, Messenger; Receptors, Somatomedin; Reproduction; Seasons; Tissue Distribution
PubMed: 33058908
DOI: 10.1016/j.ygcen.2020.113645 -
Insect Biochemistry and Molecular... Nov 2018Juvenile hormone (JH) is known to promote cell polyploidization for insect vitellogenesis and egg production, but the underlying mechanisms remain poorly understood....
Juvenile hormone (JH) is known to promote cell polyploidization for insect vitellogenesis and egg production, but the underlying mechanisms remain poorly understood. Using the migratory locust Locusta migratoria as a model system, we report here that the expression of cyclin-dependent kinase 6 (Cdk6) and adenovirus E2 factor-1 (E2f1), the core mediators in cell cycle progression is regulated by JH and its receptor Methoprene-tolerant (Met). JH acts through its receptor complex comprised of Met and Taiman to directly activate the transcription of Cdk6 and E2f1. Depletion of Cdk6 or E2f1 results in significantly decreased ploidy, precocious mitotic entry and increased cell numbers in the fat body, accompanied by substantial reduction of Vitellogenin gene expression, blocked ovarian growth and arrested oocyte maturation. These findings indicate a crucial role of Cdk6 and E2f1 in JH-regulated polyploidization and vitellogenesis as well as a novel regulatory machinery for endocycling in insects.
Topics: Animals; Cyclin-Dependent Kinase 6; E2F1 Transcription Factor; Fat Body; Female; Grasshoppers; Insect Proteins; Juvenile Hormones; Polyploidy; Transcription, Genetic; Vitellogenesis
PubMed: 30205150
DOI: 10.1016/j.ibmb.2018.09.002 -
PLoS Genetics Oct 2014Juvenile hormone (JH), a sesquiterpenoid produced by the corpora allata, coordinates insect growth, metamorphosis, and reproduction. While JH action for the repression...
Juvenile hormone (JH), a sesquiterpenoid produced by the corpora allata, coordinates insect growth, metamorphosis, and reproduction. While JH action for the repression of larval metamorphosis has been well studied, the molecular basis of JH in promoting adult reproduction has not been fully elucidated. Methoprene-tolerant (Met), the JH receptor, has been recently shown to mediate JH action during metamorphosis as well as in vitellogenesis, but again, the precise mechanism underlying the latter has been lacking. We have now demonstrated using Met RNAi to phenocopy a JH-deprived condition in migratory locusts, that JH stimulates DNA replication and increases ploidy in preparation for vitellogenesis. Mcm4 and Mcm7, two genes in the DNA replication pathway were expressed in the presence of JH and Met. Depletion of Mcm4 or Mcm7 inhibited de novo DNA synthesis and polyploidization, and resulted in the substantial reduction of vitellogenin mRNA levels as well as severely impaired oocyte maturation and ovarian growth. By using luciferase reporter and electrophoretic mobility shift assays, we have shown that Met directly regulates the transcription of Mcm4 and Mcm7 by binding to upstream consensus sequences with E-box or E-box-like motifs. Our work suggests that the JH-receptor complex acts on Mcm4 and Mcm7 to regulate DNA replication and polyploidy for vitellogenesis and oocyte maturation.
Topics: Animals; Grasshoppers; Humans; Juvenile Hormones; Larva; Methoprene; Minichromosome Maintenance Complex Component 4; Minichromosome Maintenance Complex Component 7; Nuclear Proteins; Oocytes; Oogenesis; Polyploidy; RNA Interference; RNA, Messenger; Signal Transduction; Vitellogenesis
PubMed: 25340846
DOI: 10.1371/journal.pgen.1004702 -
Frontiers in Genetics 2022Ovarian development is a key physiological process that holds great significance in the reproduction of the Chinese mitten crab (), which is an economically important...
Ovarian development is a key physiological process that holds great significance in the reproduction of the Chinese mitten crab (), which is an economically important crab species for aquaculture. However, there is limited knowledge for the regulatory mechanisms of ovarian development. To study the molecular mechanisms of its ovarian development, transcriptome analysis was performed in the ovary and hepatopancreas of during ovarian stages I (oogonium proliferation), II (endogenous vitellogenesis), and III (exogenous vitellogenesis). The results showed that 5,520 and 226 genes were differentially expressed in the ovary and hepatopancreas, respectively. For KEGG enrichment analysis, the differentially expressed genes in the ovary were significantly clustered in phototransduction-fly, phagosome, and ECM-receptor interaction. Significantly enriched pathways in the hepatopancreas included fatty acid biosynthesis, fatty acid metabolism, and riboflavin metabolism. Further analysis showed that 25 genes and several pathways were mainly involved in oogenesis, including the ubiquitin-proteasome pathway, cyclic AMP-protein kinase A signaling pathway, and mitogen-activated protein kinase signaling pathway. Twenty-five candidate genes involved in vitellogenesis and endocrine regulation were identified, such as vitellogenin, vitellogenin receptor, estrogen sulfotransferase, ecdysone receptor, prostaglandin reductase 1, hematopoietic prostaglandin D synthase and juvenile hormone acid O-methyltransferase. Fifty-six genes related to nutritional metabolism were identified, such as fatty acid synthase, long-chain-fatty-acid-CoA ligase 4, 1-acyl-sn-glycerol-3-phosphate acyltransferase 4, fatty acid-binding protein, and glycerol-3-phosphate acyltransferase 1. These results highlight the genes involved in ovarian development and nutrition deposition, which enhance our understanding of the regulatory pathways and physiological processes of crustacean ovarian development.
PubMed: 35685440
DOI: 10.3389/fgene.2022.910682 -
Journal of Morphology Apr 2021During embryogenesis, teleost females do not develop Müllerian ducts, which form the oviducts in all other vertebrates. Thus, when they reach sexual maturity they do...
During embryogenesis, teleost females do not develop Müllerian ducts, which form the oviducts in all other vertebrates. Thus, when they reach sexual maturity they do not have oviducts. In viviparous teleosts, the lack of oviducts means that the development of the embryos occurs as an intraovarian gestation, unique among vertebrates. The ovary is an unpaired hollow organ whose cavity is continuous with the caudal portion, the gonoduct, characterized by the absence of germinal cells, which opens to the exterior at the gonopore. The gonoduct attains essential function as a barrier between the germinal region of the ovary and the exterior during all reproductive stages. This study describes the functional morphology of the gonoduct in the viviparous teleost Cnesterodon decemmaculatus during non-gestation (previtellogenesis and vitellogenesis) and gestation. The ovaries were processed using histological techniques and stained with hematoxylin-eosin, and periodic acid Schiff. The gonoduct has two regions: cephalic and caudal, and is formed by three histological layers, which are, from inside to the periphery: (a) tunica mucosa; (b) tunica muscularis; and (c) tunica serosa. In the cephalic region there are mucosal folds extending into the lumen and forming a structure similar to a cervix. The histology of the gonoduct indicates essential functions, that is, (a) the control of the luminal diameter in the limit to the germinal region of the ovary by the presence of a cervix; (b) during insemination the gonoduct receives the spermatozoa, may store and transport them to the germinal region; (c) the presence of melano-macrophage centers indicates support of immunological processes, especially during gestation when these centers increase in size; (d) production of exocrine secretions; and (e) it is the birth canal, internally lined by an ciliated epithelium and surrounded by smooth musclesboth tissues supposedly supporting the birth process.
Topics: Animals; Cyprinodontiformes; Embryonic Development; Epithelium; Female; Gonads; Male; Melanocytes; Ovary; Reproduction; Spermatozoa; Vitellogenesis; Viviparity, Nonmammalian
PubMed: 33486767
DOI: 10.1002/jmor.21326 -
BMC Developmental Biology Jul 2019Insulin/insulin-like growth peptide signaling (IIS) down-regulates hemolymph sugar level and facilitates larval growth in the soybean pod borer, Maruca vitrata. The...
BACKGROUND
Insulin/insulin-like growth peptide signaling (IIS) down-regulates hemolymph sugar level and facilitates larval growth in the soybean pod borer, Maruca vitrata. The objective of this study is to determine whether IIS of M. vitrata can mediate ovarian development of adult females.
RESULTS
A pair of ovaries consists of 8 ovarioles, each of which is separated into distal germarium and proximal vitellarium in M. vitrata. In the germarium, oocyte development occurred with active mitotic activity which was visible by incorporating bromodeoxyribose uridine. Previtellogenic development and subsequent vitellogenesis began soon after adult emergence. They continued with increase of female age. Oocyte development was facilitated by up-regulation of vitellogenin (Vg) and Vg receptor (VgR) gene expression. Larval diets significantly influenced on ovarian development of M. vitrata because oocyte development varied with pupal size derived from larvae treated with different nutritional diets. Its ovarian development was dependent on endocrine signal(s) from the head because decapitation soon after adult emergence prevented oogenesis and subsequent vitellogenesis along with marked reduction of Vg and VgR expression. Topical application of juvenile hormone (JH) significantly recovered its ovarian development whereas farnesoic acid (a precursor of JH biosynthesis) or 20-hydroxyecdysone treatment did not. JH stimulated vitellogenesis and choriogenesis, but not previtellogenic development. In contrast, insulin injection to decapitated females stimulated oocyte differentiation and vitellogenesis along with increase of Vg and VgR expression. To further analyze the effect of insulin on ovarian development, expression of four IIS components (InR, FOXO, Akt, and TOR) genes was manipulated by RNA interference. Hemocoelic injection of gene-specific double stranded RNAs significantly reduced their target gene mRNA levels and interfered with ovarian development. An addition of insulin to JH treatment against decapitated females enhanced the gonadotropic effect of JH by stimulating oogenesis.
CONCLUSIONS
IIS plays crucial role in mediating previtellogenic development of M. vitrata in response to nutrient signal. It also enhances the gonadotropic effect of JH II on vitellogenesis.
Topics: Animals; Ecdysterone; Egg Proteins; Fatty Acids, Unsaturated; Female; Forkhead Box Protein O1; Insulin; Insulin-Like Growth Factor I; Juvenile Hormones; Moths; Oogenesis; Ovary; Proto-Oncogene Proteins c-akt; RNA Interference; RNA, Small Interfering; Receptors, Cell Surface; Receptors, Somatomedin; TOR Serine-Threonine Kinases; Vitellogenesis; Vitellogenins
PubMed: 31277577
DOI: 10.1186/s12861-019-0194-8 -
Biology of Reproduction Mar 2019Estrogens are involved in a wide range of processes in vertebrate reproduction through ligand activation of their specific cognate receptors. In most teleosts, three...
Estrogens are involved in a wide range of processes in vertebrate reproduction through ligand activation of their specific cognate receptors. In most teleosts, three nuclear estrogen receptor subtypes have been identified (Esr1, Esr2a, and Esr2b). Differences in ligand binding affinity and seasonal expression patterns in reproductive tissues among these Esr subtypes suggest distinct roles during oogenesis, vitellogenesis, and spermatogenesis. This study focuses on the role of the Esr subtypes in European sea bass (Dicentrarchus labrax) oogenesis and their endocrine regulation. The coding genes of the three Esr subtypes are highly expressed in reproduction-related tissues such as pituitary, gonad, and liver. Quantification of esr1, esr2a, and esr2b expression in the ovary and liver during a whole reproductive cycle showed different patterns depending on stage and subtype, suggesting differential roles of the three receptors in the regulation of oogenesis and vitellogenesis. Esr2a and Esr2b also showed differences in transcriptional activity and ligand affinity when functionally characterized in HEK293 cells. Finally, for the first time in teleosts, the localization of the three Esr subtypes in ovarian follicles and their regulation by gonadotropins is described. Immunodetection of the receptors revealed different distribution patterns in follicular cells and various subcellular locations of the oocyte. Gonadotropin stimulation of ovarian follicles in different stages of vitellogenesis showed a consistent induction of esrb2b expression by Fsh. All together, these data reinforce the hypothesis that each estrogen receptor plays a specific role in oogenesis.
Topics: Animals; Bass; Cloning, Molecular; Female; Gene Expression Regulation; Liver; Oogenesis; Phylogeny; Receptors, Estrogen; Seasons
PubMed: 30371737
DOI: 10.1093/biolre/ioy227