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Development & Reproduction Sep 2023Effects of changes in photoperiod on the reproductive events in fish are suggested to be mediated mainly via the action of melatonin (MEL). Changing levels of plasma MEL...
Effects of changes in photoperiod on the reproductive events in fish are suggested to be mediated mainly via the action of melatonin (MEL). Changing levels of plasma MEL throughout the day and year are suggested to influence the hypothalamus-pituitary-gonadal axis in fish. Therefore, in this study, we aimed to investigate the effects of MEL on oocyte maturation and germinal vesicle breakdown (GVBD) in the marine fish, , . Oocytes at three different stages (pre-, mid-, and late-vitellogenesis) were incubated with (a) only MEL (5, 10, 50, 100, 500, and 1,000 pg/mL) and (b) 50 pg/mL of 17α,20β-dihydroxy-4-pregnen-3-one (17α20βP), maturation-inducing hormone (MIH) of this species, and MEL (4-h incubation before addition of MIH). Any single MEL treatment did not significantly induce GVBD. However, treatment with 50 pg/mL MEL or MIH significantly induced GVBD. These results suggest that preincubation with MEL accelerates the effect of MIH on longchin goby oocyte maturation.
PubMed: 38074459
DOI: 10.12717/DR.2023.27.3.127 -
BioRxiv : the Preprint Server For... Apr 2024The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We...
The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in partially suppress the vitellogenesis defects observed in the heterochronic mutants and both of which ectopically express at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that functions in concert with , a cullin gene, and the Skp1-related gene to regulate vitellogenesis. Additionally, acts genetically upstream of , which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.
PubMed: 38712300
DOI: 10.1101/2024.04.18.590113 -
Current Issues in Molecular Biology Jul 2023The banana prawn () is a valuable prawn in the worldwide market. However, cultivation of this species is limited owing to the difficulty in culture management and...
The banana prawn () is a valuable prawn in the worldwide market. However, cultivation of this species is limited owing to the difficulty in culture management and limited knowledge of reproduction. Therefore, we studied the gene expression and molecular mechanisms involved in oogenesis for elucidating ovarian germ cell development in banana prawns. The tissue-specific distribution of certain genes identified from previous transcriptome data showed that , , and nuclear autoantigenic sperm protein () were only expressed in gonads. The in situ hybridization (ISH) of these three genes showed different expression patterns throughout oogenesis. was highly expressed in pre-vitellogenic oocytes. was expressed at almost the same level during oogenesis but showed the most expression in late pre-vitellogenic stages. Based on the highest expression of and in mid pre-vitellogenic and late pre-vitellogenic oocytes, respectively, we suggested that FmNanos may suppress FmCyclinB expression before initiation of vitellogenesis. Meanwhile, expression was detected only in pre-vitellogenesis. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) analysis of expression was supported by F ISH analysis based on high expression of in sub-adult ovaries, which contain most of pre-vitellogenic oocytes. In this study, we found three reliable ovarian markers for banana prawns and also found a dynamic change of molecular mechanism during the sub-stage of pre-vitellogenesis. We determined the expression levels of these genes involved in oogenesis. Our findings provide information for further studies on banana prawn reproduction which may assist in their cultivation.
PubMed: 37504276
DOI: 10.3390/cimb45070360 -
Antioxidants (Basel, Switzerland) Dec 2023Vitamin B12 is an essential cofactor involved in the function of two enzymes: cytosolic methionine synthase and mitochondrial methylmalonic-CoA mutase. In our previous...
Vitamin B12 is an essential cofactor involved in the function of two enzymes: cytosolic methionine synthase and mitochondrial methylmalonic-CoA mutase. In our previous studies, caffeine (1,3,7-trimethylxanthine), the most popular bioactivator, was shown to reduce yolk protein (vitellogenin) and fertility in a model. Based on the previous finding that methionine supplementation increases vitellogenesis in , we investigated the role of vitamin B12 in methionine-mediated vitellogenesis during oogenesis in caffeine-ingested animals (CIA). Vitamin B12 supplementation improved vitellogenesis and reduced oxidative stress by decreasing mitochondrial function in CIA. Furthermore, the decreased number of developing oocytes and high levels of reactive oxygen species in oocytes from CIA were recovered with vitamin B12 supplementation through a reduction in mitochondrial stress, which increased vitellogenesis. Taken together, vitamin B12 supplementation can reverse the negative effects of caffeine intake by enhancing methionine-mediated vitellogenesis and oocyte development by reducing mitochondrial stress.
PubMed: 38247478
DOI: 10.3390/antiox13010053 -
IScience Feb 2024Energy reserves, primarily stored in the insect's fat body, are essential for physiological processes such as reproduction and cocoon formation. However, whether these...
Energy reserves, primarily stored in the insect's fat body, are essential for physiological processes such as reproduction and cocoon formation. However, whether these processes are mutually constraining is unknown. Here, we showed that cocoon-free silkworms accumulate amino acid constituents of silk proteins in the hemolymph and maintain lipid and sugar reserves in the pupal fat body by repressing the expression of sericin and fibroin genes in the middle and posterior silk glands, respectively, via butterfly pierisin-1A catalytic domain expression. This, in turn, upregulates insulin/insulin-like signaling and target of rapamycin (IIS/TOR) signaling, which enhances vitellogenesis and accelerates ovarian development, thus contributing to increased fecundity. The impacts of semi-starvation on fecundity and egg hatchability were also less pronounced in cocoon-free silkworms compared with wildtype silkworms. These data uncover the resource allocation trade-off between cocoon formation and fecundity and demonstrate that nutritional signaling plays a role in regulating silkworm reproduction.
PubMed: 38303707
DOI: 10.1016/j.isci.2024.108853 -
Cells Nov 2023(1) Fshβ and Lhβ showed stronger signals and higher transcript levels from 590 to 1050 dph than at earlier stages, implying their active involvement during primary...
Chronological Changes in Gonadotropin-Releasing Hormone 1, Gonadotropins, and Sex Steroid Hormones along the Brain-Pituitary-Gonadal Axis during Gonadal Sex Differentiation and Development in the Longtooth Grouper, .
(1) Fshβ and Lhβ showed stronger signals and higher transcript levels from 590 to 1050 dph than at earlier stages, implying their active involvement during primary oocyte development. (2) Fshβ and Lhβ at lower levels were detected during the phases of ovarian differentiation and oogonial proliferation. (3) E concentrations increased significantly at 174, 333, and 1435 dph, while T concentrations exhibited significant increases at 174 and 333 dph. These findings suggest potential correlations between serum E concentrations and the phases of oogonial proliferation and pre-vitellogenesis.
Topics: Female; Animals; Bass; Sex Differentiation; Gonadotropin-Releasing Hormone; Gonadal Steroid Hormones; Follicle Stimulating Hormone, beta Subunit; Luteinizing Hormone, beta Subunit; Brain
PubMed: 37998369
DOI: 10.3390/cells12222634 -
International Journal of Molecular... Jan 2024Vitellogenin () is a precursor of yolk proteins in egg-laying vertebrates and invertebrates and plays an important role in vitellogenesis and embryonic development....
Vitellogenin () is a precursor of yolk proteins in egg-laying vertebrates and invertebrates and plays an important role in vitellogenesis and embryonic development. However, the family remains poorly characterized in , a major commercial mariculture species found along the coasts of the Yellow and Bohai Seas. In this study, 10 genes from the genomes of were identified and characterized. Phylogenetic analyses showed that the genes in crustaceans could be classified into four groups: Astacidea, Brachyra, Penaeidae, and Palaemonidae. genes were unevenly distributed on the chromosomes of , and a molecular evolutionary analysis showed that the genes were primarily constrained by purifying selection during evolution. All putative proteins were characterized by the presence of three conserved functional domains: a lipoprotein N-terminal domain (LPD_N), a domain of unknown function (DUF1943), and a von Willebrand factor type D domain (vWD). All genes exhibited higher expression in the female hepatopancreas than in other tissues, and gene expression during ovarian development suggested that the hepatopancreas is the main synthesis site in . , , and play major roles in exogenous vitellogenesis, and also plays a major role in endogenous vitellogenesis. Bilateral ablation of the eyestalk significantly upregulates mRNA expression in the female hepatopancreas, indicating that the X-organ/sinus gland complex plays an important role in ovarian development, mostly by inducing synthesis. These results could improve our understanding of the function of multiple genes in crustaceans and aid future studies on the function of genes during ovarian development in .
Topics: Animals; Female; Vitellogenins; Palaemonidae; Phylogeny; Embryonic Development; Evolution, Molecular
PubMed: 38256163
DOI: 10.3390/ijms25021089 -
Nutrients Mar 2024Caffeine (1,3,7-trimethylxanthine) is a widely consumed bioactive substance worldwide. Our recent study showed that a reduction in both reproduction and yolk protein...
Caffeine (1,3,7-trimethylxanthine) is a widely consumed bioactive substance worldwide. Our recent study showed that a reduction in both reproduction and yolk protein production (vitellogenesis) caused by caffeine intake were improved by vitamin B12 supplementation, which is an essential co-factor in methionine metabolism. In the current study, we investigated the role of methionine in the reproduction of caffeine-ingested animals (CIAs). We assessed the effect of methionine metabolism on CIAs and found that caffeine intake decreased both methionine levels and essential enzymes related to the methionine cycle. Furthermore, we found that the caffeine-induced impairment of methionine metabolism decreased vitellogenesis and increased germ cell apoptosis in an LIN-35/RB-dependent manner. Interestingly, the increased germ cell apoptosis was restored to normal levels by methionine supplementation in CIAs. These results indicate that methionine supplementation plays a beneficial role in germ cell health and offspring development by regulating vitellogenesis.
Topics: Animals; Methionine; Caenorhabditis elegans; Caffeine; Apoptosis; Germ Cells; Racemethionine; Dietary Supplements
PubMed: 38542805
DOI: 10.3390/nu16060894 -
BMC Zoology Jul 2023The precise mechanisms of hormone action responsible for the full course of events modulating folliculogenesis in crocodilian have not been determined, although...
BACKGROUND
The precise mechanisms of hormone action responsible for the full course of events modulating folliculogenesis in crocodilian have not been determined, although histological features have been identified.
RESULTS
The Alligator sinensis ovarian morphological characteristics observed at 1, 15, 30, 60, 90, and 300 days post hatching(dph) revealed that the dynamic changes in germ cells varied in different meiotic and developmental stages, confirming that the processes of folliculogenesis were protracted and asynchronous. The presence of endogenous follicle-stimulating hormone(FSH) mRNA and protein expression within the cerebrum at 1 dph, in parallel with the increase in germ cells within the germ cell nests(Nest) from 1 dph to 15 dph, suggested that endocrine regulation of the pituitary-gonad axis is an early event in oogonia division. Furthermore, the endogenous expression of FSH showed a trend of negative feedback augmentation accompanied by the exhaustion of maternal yolk E observed at 15 dph. Such significant elevation of endogenous FSH levels was observed to be related to pivotal events in the transition from mitosis to meiosis, as reflected by the proportion of oogonia during premeiosis interphase, with endogenous FSH levels reaching a peak at the earliest time step of 1 dph. In addition, the simultaneous upregulation of premeiotic marker STRA8 mRNA expression and the increase in endogenous FSH further verified the above speculation. The strongly FSHr-positive label in the oocytes within Pre-previtellogenic follicles was synchronized with the significant elevation of ovarian cAMP detected at 300 dph, which suggested that diplotene arrest maintenance during early vitellogenesis might be FSH dependent. In addition, preferential selection in asynchronous meiotic initiation has been supposed to act on somatic supportive cells and not directly on germ cells via regulation of FSH that in turn affects downstream estrogen levels. This suggestion was verified by the reciprocal stimulating effect of FSH and E on the accelerated meiotic marker SYCP3 and by the inhibited cell apoptosis demonstrated in ovarian cell culture in vitro.
CONCLUSION
The corresponding results contribute an expansion of the understanding of physiological processes and shed some light on the specific factors responsible for gonadotropin function in the early folliculogenesis of crocodilians.
PubMed: 37403129
DOI: 10.1186/s40850-023-00170-z -
International Journal of Molecular... Dec 2023Methyl farnesoate (MF), a crucial sesquiterpenoid hormone, plays a pivotal role in the reproduction of female crustaceans, particularly in the vitellogenesis process....
Methyl farnesoate (MF), a crucial sesquiterpenoid hormone, plays a pivotal role in the reproduction of female crustaceans, particularly in the vitellogenesis process. Despite extensive research on its functions, the molecular mechanisms that regulate MF levels during the vitellogenic phase remain largely elusive. This study investigates the roles of microRNAs (miRNAs), significant post-transcriptional regulators of gene expression, in controlling MF levels in the swimming crab . Through bioinformatic analysis, four miRNAs were identified as potential regulators targeting two genes encoding Carboxylesterases (CXEs), which are key enzymes in MF degradation. Dual luciferase reporter assays revealed that and suppress and expression by directly binding to their 3' UTRs. In vivo overexpression of and significantly diminished and levels, consequently elevating hemolymph MF and enhancing expression. Spatiotemporal expression profile analysis showed that these two miRNAs and their targets exhibited generally opposite patterns during ovarian development. These findings demonstrate that and collaboratively modulate MF levels by targeting , thus influencing vitellogenesis in . Additionally, we found that the expression of and were suppressed by MF, constituting a regulatory loop for the regulation of MF levels. The findings contribute novel insights into miRNA-mediated ovarian development regulation in crustaceans and offer valuable information for developing innovative reproduction manipulation techniques for .
Topics: Animals; Female; 3' Untranslated Regions; Brachyura; Carboxylic Ester Hydrolases; Fatty Acids, Unsaturated; MicroRNAs; Vitellogenesis
PubMed: 38203450
DOI: 10.3390/ijms25010279