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Bioscience Reports Oct 2015Ovarian development in crustaceans is characterized by rapid production of egg yolk protein in a process called vitellogenesis. In the present study, we investigated the...
Ovarian development in crustaceans is characterized by rapid production of egg yolk protein in a process called vitellogenesis. In the present study, we investigated the involvement of a DEAD (Asp-Glu-Ala-Asp) box RNA helicase 20 (DDX20), forkhead transcription factor (FOXL)2 and fushi tarazu factor (FTZ-F)1 in the regulation of vitellogenesis. Based on ESTs from the testis and accessory gland of Eriocheir sinensis, we cloned the full-length cDNAs of foxl2 and fushitarazu factor 1 (ftz-f1), which include the conserved structural features of the forkhead family and nuclear receptor 5A (NR5A) family respectively. The expression of foxl2 mRNA surged at the mature stage of the ovary, when vtg mRNA swooped, suggesting that foxl2 negatively affects the vitellogenin (VTG) synthesis at this developmental stage. Etoposide (inducing germ cell apoptosis) treatment up-regulated FOXL2 and DDX20 at both the mRNA and the protein levels, primarily in the follicular cells as shown by immunofluorescence analysis. Furthermore, foxl2, ddx20 and ftz-f1 mRNA levels increased significantly with right-eyestalk ablation. Interactions between FOXL2 and DDX20 or FTZ-F1 were confirmed by co-immunoprecipitation and the forkhead domain of FOXL2 was identified as the specific structure interacting with FTZ-F1. In conclusion, FOXL2 down-regulates VTG expression by binding with DDX20 in regulation of follicular cell apoptosis and with FTZ-F1 to repress the synthesis of VTG at the mature stage. This report is the first to describe the molecular mechanism of VTG synthesis in E. sinensis and may shed new light on the regulation of cytochrome P450 enzyme by FOXL2 and FTZ-F1 in vitellogenesis.
Topics: Animals; Brachyura; Cytochrome P-450 Enzyme System; DEAD Box Protein 20; Forkhead Transcription Factors; Gene Expression Regulation, Developmental; RNA, Messenger; Steroidogenic Factor 1; Vitellogenins
PubMed: 26430246
DOI: 10.1042/BSR20150151 -
PloS One 2013Oocyte maturation in fish involves numerous cell signaling cascades that are activated or inhibited during specific stages of oocyte development. The objectives of this...
BACKGROUND
Oocyte maturation in fish involves numerous cell signaling cascades that are activated or inhibited during specific stages of oocyte development. The objectives of this study were to characterize molecular pathways and temporal gene expression patterns throughout a complete breeding cycle in wild female largemouth bass to improve understanding of the molecular sequence of events underlying oocyte maturation.
METHODS
Transcriptomic analysis was performed on eight morphologically diverse stages of the ovary, including primary and secondary stages of oocyte growth, ovulation, and atresia. Ovary histology, plasma vitellogenin, 17β-estradiol, and testosterone were also measured to correlate with gene networks.
RESULTS
Global expression patterns revealed dramatic differences across ovarian development, with 552 and 2070 genes being differentially expressed during both ovulation and atresia respectively. Gene set enrichment analysis (GSEA) revealed that early primary stages of oocyte growth involved increases in expression of genes involved in pathways of B-cell and T-cell receptor-mediated signaling cascades and fibronectin regulation. These pathways as well as pathways that included adrenergic receptor signaling, sphingolipid metabolism and natural killer cell activation were down-regulated at ovulation. At atresia, down-regulated pathways included gap junction and actin cytoskeleton regulation, gonadotrope and mast cell activation, and vasopressin receptor signaling and up-regulated pathways included oxidative phosphorylation and reactive oxygen species metabolism. Expression targets for luteinizing hormone signaling were low during vitellogenesis but increased 150% at ovulation. Other networks found to play a significant role in oocyte maturation included those with genes regulated by members of the TGF-beta superfamily (activins, inhibins, bone morphogenic protein 7 and growth differentiation factor 9), neuregulin 1, retinoid X receptor, and nerve growth factor family.
CONCLUSIONS
This study offers novel insight into the gene networks underlying vitellogenesis, ovulation and atresia and generates new hypotheses about the cellular pathways regulating oocyte maturation.
Topics: Animals; Bass; Cluster Analysis; Computational Biology; Estrogens; Female; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Regulatory Networks; Integrin alpha5beta1; Male; Oogenesis; Ovary; Reproduction; Signal Transduction; Vitellogenins; beta Catenin
PubMed: 23527095
DOI: 10.1371/journal.pone.0059093 -
Frontiers in Physiology 2019Vitellogenin (Vg) is precursor of vitellin. Here, we identified a () and two -likes (-like1 and -like2) in the brown planthopper, . Phylogenetic analyses showed that...
Vitellogenin (Vg) is precursor of vitellin. Here, we identified a () and two -likes (-like1 and -like2) in the brown planthopper, . Phylogenetic analyses showed that NlVg-like1 and NlVg-like2 are not clustered with the conventional insect Vgs associated with vitellogenesis. Temporo-spatial expression analyses showed that the and -like2 transcript levels increased significantly 24 h after emergence and were primarily expressed in female adults. However, -like1 was expressed during all stages, and in both genders. Tissue-specific analyses showed that all three genes were most highly expressed in the fat body. The injection of double-stranded RNA targeting showed that is essential not only for oocyte development but also for nymph development. The knockdown of -like1 in female adults resulted in failure to hatch or death before eggshell emergence in 18% of offspring embryos, suggesting that -like1 plays an important role during late embryogenesis. Approximately 65% of eggs laid by females that were treated with double-stranded RNA targeting -like2 failed to hatch, indicating that -like2 plays a role in nutrition absorption during oocyte, or embryonic development. Our results illustrate the structural and functional differences among the and -like genes and provide potential targets for RNA-interference-based insect pest management strategies.
PubMed: 31620015
DOI: 10.3389/fphys.2019.01181 -
Ecology and Evolution Nov 2015Viviparous lizards living in cold climate of high altitude often exhibit atypical reproductive cycles, in which mating and fertilization occur synchronously and annually...
Viviparous lizards living in cold climate of high altitude often exhibit atypical reproductive cycles, in which mating and fertilization occur synchronously and annually with parturition occurring at the end of the year. Nevertheless, detailed case studies on atypical reproductive cycles are few. Using anatomical data combined with behavioral observations, we examined the reproductive cycle of a common Asian agamid, Phrynocephalus vlangalii, from a high-elevation area in Sichuan, China. Male spermiation of P. vlangalii occurred in May, and spermatogenesis began in June and reached a maximum in October. For females, ovulation and fertilization occurred in May, and females developed gestation and pregnancy in 3 months from June to August, without vitellogenesis during this period. Females gave birth synchronously in late August, then vitellogenesis began and lasted until May of the next year. All adult males and females were synchronized in the same reproductive condition each month. The synchronous and annual reproductive cycle of P. vlangalii clearly represents an atypical cycle. The male courtship and mating behaviors were concordant with gonadal cycle and mainly happened in May and June. Despite the short growth period for neonates, they had a high over-winter survival rate of 84.4%, suggesting that autumn parturition did not generate high costs to this reproductive cycle. We propose that the high over-winter survival rate of neonates is likely linked with female delayed sexual maturity, female asynchronous vitellogenesis and gestation, large relative clutch mass (RCM), and adult-offspring burrow sharing behavior during hibernation.
PubMed: 26640688
DOI: 10.1002/ece3.1783 -
Development (Cambridge, England) Mar 2022Despite their medical and economic relevance, it remains largely unknown how suboptimal temperatures affect adult insect reproduction. Here, we report an in-depth...
Despite their medical and economic relevance, it remains largely unknown how suboptimal temperatures affect adult insect reproduction. Here, we report an in-depth analysis of how chronic adult exposure to suboptimal temperatures affects oogenesis using the model insect Drosophila melanogaster. In adult females maintained at 18°C (cold) or 29°C (warm), relative to females at the 25°C control temperature, egg production was reduced through distinct cellular mechanisms. Chronic 18°C exposure improved germline stem cell maintenance, survival of early germline cysts and oocyte quality, but reduced follicle growth with no obvious effect on vitellogenesis. By contrast, in females at 29°C, germline stem cell numbers and follicle growth were similar to those at 25°C, while early germline cyst death and degeneration of vitellogenic follicles were markedly increased and oocyte quality plummeted over time. Finally, we also show that these effects are largely independent of diet, male factors or canonical temperature sensors. These findings are relevant not only to cold-blooded organisms, which have limited thermoregulation, but also potentially to warm-blooded organisms, which are susceptible to hypothermia, heatstroke and fever.
Topics: Animals; Cell Lineage; Cold Temperature; Drosophila melanogaster; Female; Gene Expression Regulation, Developmental; Germ Cells; Male; Oocytes; Oogenesis; Ovarian Follicle; Ovary; Signal Transduction; Stem Cells; Vitellogenesis
PubMed: 35156684
DOI: 10.1242/dev.200149 -
Frontiers in Endocrinology 2021Red pigment concentrating hormone (RPCH) and pigment dispersing hormone (PDH) are crustacean neuropeptides involved in broad physiological processes including body color...
Red pigment concentrating hormone (RPCH) and pigment dispersing hormone (PDH) are crustacean neuropeptides involved in broad physiological processes including body color changes, circadian rhythm, and ovarian growth. In this study, the full-length cDNA of and were identified from the brain of the Chinese mitten crab . The deduced RPCH and PDH mature peptides shared identical sequence to the adipokinetic hormone/RPCH peptides family and the β-PDH isoforms and were designated as Es-RPCH and Es-β-PDH, respectively. and transcripts were distributed in the brain and eyestalks. The positive signals of and were localized in the neuronal clusters 6, 8, 9, 10, and 17 of the brain as revealed by hybridization. The expression level of and mRNA in nervous tissues were all significantly increased at vitellogenic stage, and then decreased at the final meiotic maturation stage. The administrated with synthesized Es-RPCH peptide results in germinal vesicles shift toward the plasma membrane in vitellogenic oocyte, and significant decrease of the gonad-somatic index (GSI) and mean oocyte diameter as well as the expression of vitellogenin mRNA at 30 days post injection . Similar results were also found when injection of the Es-β-PDH peptide. culture demonstrated that Es-RPCH and Es-β-PDH induced germinal vesicle breakdown of the late vitellogenic oocytes. Comparative ovarian transcriptome analysis indicated that some reproduction/meiosis-related genes such as cdc2 kinase, cyclin B, 5-HT-R and retinoid-X receptor were significantly upregulated in response to Es-RPCH and Es-β-PDH treatments. Taken together, these results provided the evidence for the inductive effect of and on the oocyte meiotic maturation in .
Topics: Animals; Brachyura; Brain Chemistry; China; DNA, Complementary; Female; Gene Expression; Meiosis; Oligopeptides; Oocytes; Ovary; Peptides; Pyrrolidonecarboxylic Acid; RNA, Messenger; Vitellogenesis
PubMed: 34975771
DOI: 10.3389/fendo.2021.802768 -
The Journal of Biological Chemistry Mar 2016Although juvenile hormone (JH) is known to prevent insect larval metamorphosis and stimulate adult reproduction, the molecular mechanisms of JH action in insect...
Although juvenile hormone (JH) is known to prevent insect larval metamorphosis and stimulate adult reproduction, the molecular mechanisms of JH action in insect reproduction remain largely unknown. Earlier, we reported that the JH-receptor complex, composed of methoprene-tolerant and steroid receptor co-activator, acts on mini-chromosome maintenance (Mcm) genes Mcm4 and Mcm7 to promote DNA replication and polyploidy for the massive vitellogenin (Vg) synthesis required for egg production in the migratory locust (Guo, W., Wu, Z., Song, J., Jiang, F., Wang, Z., Deng, S., Walker, V. K., and Zhou, S. (2014) PLoS Genet. 10, e1004702). In this study we have investigated the involvement of cell-division-cycle 6 (Cdc6) in JH-dependent vitellogenesis and oogenesis, as Cdc6 is essential for the formation of prereplication complex. We demonstrate here that Cdc6 is expressed in response to JH and methoprene-tolerant, and Cdc6 transcription is directly regulated by the JH-receptor complex. Knockdown of Cdc6 inhibits polyploidization of fat body and follicle cells, resulting in the substantial reduction of Vg expression in the fat body as well as severely impaired oocyte maturation and ovarian growth. Our data indicate the involvement of Cdc6 in JH pathway and a pivotal role of Cdc6 in JH-mediated polyploidization, vitellogenesis, and oogenesis.
Topics: Amino Acid Sequence; Animals; Cell Cycle Proteins; Cell Line; Drosophila Proteins; Drosophila melanogaster; Fat Body; Female; Grasshoppers; Juvenile Hormones; Molecular Sequence Data; Ovarian Follicle; Polyploidy; Transcriptional Activation; Vitellins; Vitellogenesis
PubMed: 26728459
DOI: 10.1074/jbc.M115.698936 -
Insects Jan 2021DEAD-box protein 6 (DDX6) is a member of the DDX RNA helicase family that exists in all eukaryotes. It has been extensively studied in yeast and mammals and has been...
DEAD-box protein 6 (DDX6) is a member of the DDX RNA helicase family that exists in all eukaryotes. It has been extensively studied in yeast and mammals and has been shown to be involved in messenger ribonucleoprotein assembly, mRNA storage, and decay, as well as in miRNA-mediated gene silencing. DDX6 participates in many developmental processes but the biological function of DDX6 in insects has not yet been adequately addressed. Herein, we characterized the gene that encodes the LmDDX6 protein in , a global, destructive pest. LmDDX6 possesses five motifs unique to the DDX6 subfamily. In the phylogenetic tree, LmDDX6 was closely related to its orthologs in and . RT-qPCR data revealed high expression of in the ovary, muscle, and fat body, with a declining trend in the ovary after adult ecdysis. knockdown downregulated the expression levels of the juvenile hormone receptor and genes encoding Met downstream targeted and , reduced expression, and impaired ovary development and oocyte maturation. These results demonstrate that plays an essential role in locust female reproduction and, thus, could be a novel target for locust biological control.
PubMed: 33466820
DOI: 10.3390/insects12010070 -
Endocrine Connections Nov 2019The pituitary gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are the principle endocrine drivers of reproductive processes in the gonads...
The pituitary gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are the principle endocrine drivers of reproductive processes in the gonads of jawed vertebrates. Canonically, FSH recruits and maintains selected ovarian follicles for maturation and LH induces the stages of germinal vesicle breakdown and ovulation. In mammals, LH and FSH specifically activate cognate G-protein-coupled receptors that affect the proteins involved in steroidogenesis, protein hormone synthesis, and gametogenesis. This dual-gonadotropin model also exists in some fish species, but not in all. In fact, due to their diverse number of species, extended number of ecological niches, and remarkably flexible reproductive strategies, fish are appropriate as models to understand the co-evolution of gonadotropins and their receptors. In this study, we cloned and characterized the expression profile over the final stages of ovarian maturation of carp (Cyprinus carpio) LHCGR and FSHR. Expression of both gonadotropin receptors increased in the later stage of early vitellogenesis, suggesting that both LH and FSH play a role in the development of mature follicles. We additionally tested the activation of cLHCGR and cFSHR using homologous and heterologous recombinant gonadotropins in order to gain insight into an evolutionary model of permissive gonadotropin receptor function. These data suggest that carp (Cyprinus carpio) gonad development and maturation depends on a specific gonadotropin profile that does not reflect the temporally distinct dual-gonadotropin model observed in salmonids or mammals, and that permissive gonadotropin receptor activation is a specific feature of Ostariophysi, not all teleosts.
PubMed: 31581128
DOI: 10.1530/EC-19-0389 -
Animal Reproduction Dec 2018Research concerning to characterize seasonal reproductive cycle in males and females of by ultrasound and hormonal measurement. Reproductive aspects (follicular and...
Research concerning to characterize seasonal reproductive cycle in males and females of by ultrasound and hormonal measurement. Reproductive aspects (follicular and testicular cycles, and pregnancy) from 28 adult snakes (14 males and 14 females) during different months of the years were studied. Snakes housed individually in cages in an environment with controlled luminosity and humidity, and fed monthly. Females were examined by ultrasound during quiescence and active follicular phase, and pregnancy for follicular and embryo/fetal development. Males were evaluated to testicular echotexture and measurements during reproductive and non-reproductive season. The blood samples were collected from males and females for serum testosterone and progesterone determination, respectively. In 77% males the testes were identified by ultrasound and found increased size during summer, decreased serum testosterone in winter, and positive correlation between serum testosterone and testes size. There was no change in testicular echotexture in according to season. Testosterone concentration was decreased during winter and it was positively correlated with testes size. In 71% females, were observed follicular development (vitellogenesis) and gestation since winter to spring by ultrasonography. Parturition occurred mainly in summer. Pregnancy length was 123.0 ± 11.4 days, with mean 6.9 ± 1.5 newborns/female, and there was gradual increase of serum progesterone during this period. There was no variation in progesterone concentration in non-gravid females. Males and females Tropical Rattlesnake show seasonal variation of reproductive cycle and was clear a biennial cycle in female. The ultrasonography can be considered an essential tool to accomplish the follicular development, pregnancy and testicular alterations in Tropical Rattlesnake.
PubMed: 34221138
DOI: 10.21451/1984-3143-AR2017-0019