Quantity Of Gametes Research Articles

Systemic low-dose anti-fibrotic treatment attenuates ovarian aging in the mouse.

The female reproductive system is one of the first to age in humans, resulting in infertility and endocrine disruptions. The aging ovary assumes a fibro-inflammatory milieu which negatively impacts gamete quantity and quality as well as ovulation. Here, we tested whether the systemic delivery of anti-inflammatory (Etanercept) or anti-fibrotic (Pirfenidone) drugs attenuates ovarian aging in mice. We first evaluated the ability of these drugs to decrease the expression of fibro-inflammatory genes in primary ovarian stromal cellstreated with a pro-fibrotic or a pro-inflammatory stimulus. Whereas Etanercept did not block Tnf expression in ovarian stromal cells, Pirfenidone significantly reduced Col1a1 expression. We then tested Pirfenidone in vivo where the drug was delivered systemically via mini-osmotic pumps for 6weeks. Pirfenidone mitigated the age-dependent increase in ovarian fibrosis without impacting overall health parameters. Ovarian function was improved in Pirfenidone-treated mice as evidenced by increased follicle and corpora lutea number, AMH levels, and improved estrous cyclicity. Transcriptomic analysis revealed that Pirfenidone treatment resulted in an upregulation of reproductive function-related genes at 8.5months and a downregulation of inflammatory genes at 12months of age. These findings demonstrate that reducing the fibroinflammatory ovarian microenvironment improves ovarian function, thereby supporting modulating the ovarian environment as a therapeutic avenue to extend reproductive longevity.

Systemic low-dose anti-fibrotic treatment attenuates ovarian aging in the mouse.

The female reproductive system is one of the first to age in humans, resulting in infertility and endocrine disruptions. The aging ovary assumes a fibro-inflammatory milieu which negatively impacts gamete quantity and quality as well as ovulation. Here we tested whether the systemic delivery of anti-inflammatory (Etanercept) or anti-fibrotic (Pirfenidone) drugs attenuates ovarian aging in mice. We first evaluated the ability of these drugs to decrease the expression of fibro-inflammatory genes in primary ovarian stromal cells. Whereas Etanercept did not block Tnf expression in ovarian stromal cells, Pirfenidone significantly reduced Col1a1 expression. We then tested Pirfenidone in vivo where the drug was delivered systemically via mini-osmotic pumps for 6-weeks. Pirfenidone mitigated the age-dependent increase in ovarian fibrosis without impacting overall health parameters. Ovarian function was improved in Pirfenidone-treated mice as evidenced by increased follicle and corpora lutea number, AMH levels, and improved estrous cyclicity. Transcriptomic analysis revealed that Pirfenidone treatment resulted in an upregulation of reproductive function-related genes at 8.5 months and a downregulation of inflammatory genes at 12 months of age. These findings demonstrate that reducing the fibroinflammatory ovarian microenvironment improves ovarian function, thereby supporting modulating the ovarian environment as a therapeutic avenue to extend reproductive longevity.

Puncture vine (Tribulus Terrestris L.) in control of health and reproduction.

Tribulus terrestris, L. (puncture vine) have been used as a folk medicine for five thousands of years, but its targets, effects, their mechanisms and application requires further studies. This paper reviews the provenance, constituents and properties of Tribulus terrestris, L., its general physiological and health effects, as well as the currently available knowledge concerning its influence on male and female reproductive processes and their dysfunctions. Analysis of the available publications demonstrated the influence of Tribulus terrestris on a wide spectrum of targets and physiological processe and disorders. In particular, Tribulus terrestris can be a stimulator of male and female reproductive processes at the level of central nervous system, sexual behaviour, pituitary and gonadal hormones and their receptors, gonadal functions (including ovarian follicullogenesis and spermatogenesis), improvement of the quality and quantity of gametes (at least of sperm) and fecundity. This ability of puncture vine is applicable for the improvement of man's sexual desire and sperm quality in vivo and in vitro, as well as of women's libido, activation of women's reproductive organs, fecundity, and treatment of infertility, especially that related to the polycystic ovarian syndrome.

Puncture vine (Tribulus Terrestris L.) in control of health and reproduction

Tribulus terrestris, L. (puncture vine) have been used as a folk medicine for five thousands of years, but its targets, effects, their mechanisms and application requires further studies. This paper reviews the provenance, constituents and properties of Tribulus terrestris, L., its general physiological and health effects, as well as the currently available knowledge concerning its influence on male and female reproductive processes and their dysfunctions. Analysis of the available publications demonstrated the influence of Tribulus terrestris on a wide spectrum of targets and physiological processe and disorders. In particular, Tribulus terrestris can be a stimulator of male and female reproductive processes at the level of central nervous system, sexual behaviour, pituitary and gonadal hormones and their receptors, gonadal functions (including ovarian follicullogenesis and spermatogenesis), improvement of the quality and quantity of gametes (at least of sperm) and fecundity. This ability of puncture vine is applicable for the improvement of man’s sexual desire and sperm quality in vivo and in vitro, as well as of women’s libido, activation of women’s reproductive organs, fecundity, and treatment of infertility, especially that related to the polycystic ovarian syndrome.

Histologic analysis and lipid profiling reveal reproductive age-associated changes in peri-ovarian adipose tissue

BackgroundReproductive aging is a robust phenotype that occurs in all females and is characterized by a significant reduction in gamete quantity and quality, which can have negative consequences on both endocrine function and fertility. Age-associated differences in the oocyte, follicle, and ovary have been well-documented, but how the broader environment changes with age is less well understood. Fat is one of the largest organs in the body, and peri-gonadal adipose tissue surrounds the rodent ovary and comprises a local ovarian environment. The goal of this study was to characterize how peri-ovarian adipose tissue changes with advanced reproductive age.MethodsWe isolated peri-gonadal adipose tissue from two cohorts of CB6F1 mice: reproductively young (6–12 weeks) and reproductively old (14–17 months). A comparative histological analysis was performed to evaluate adipocyte architecture. We then extracted lipids from the tissue and performed multiple reaction monitoring (MRM)-profiling, a mass spectrometry-based method of metabolite profiling, to compare the lipid profiles of peri-gonadal adipose tissue in these age cohorts.ResultsWe found that advanced reproductive age was associated with adipocyte hypertrophy and a corresponding decrease in the number of adipocytes per area. Of the 10 lipid classes examined, triacylglycerols (TAGs) had significantly different profiles between young and old cohorts, despite quantitative analysis revealing a decrease in the total amount of TAGs per weight of peri-gonadal adipose tissue with age.ConclusionsThese findings pinpoint age-associated physiological changes in peri-gonadal adipose tissue with respect to adipocyte morphology and lipid profiles and lay the foundation for future studies to examine how these alterations may influence both adipocyte and ovarian function.

Germline stem cell homeostasis.

In many species, germline stem cells (GSCs) function to sustain gametogenesis throughout the life of organismal life span. As the source of gametes, the only cell type that can pass the genetic information to the next generation, GSCs play a fundamental role in maximizing the quantity of gametes that animals produce, while ensuring their highest quality. GSCs are maintained by the signals from their niches, and germ cells that exited the niche undergo differentiation to generate functional gametes. GSC population is sustained by a multitude of mechanisms such as asymmetric stem cell divisions and dedifferentiation of partially differentiated germ cells. In this review, we summarize the mechanisms that maintain GSC homeostasis to ensure life-long production of functional gametes.

Dietary pollutants induce oxidative stress, altering maternal antioxidant provisioning and reproductive output in the temperate sea urchin Evechinus chloroticus

Evidence is growing to suggest that the capacity to withstand oxidative stress may play an important role in shaping life-history trade-offs, although little is known on the relationship in broadcast spawning marine invertebrates. In this group, variation in gamete quantity and quality are important drivers of offspring survival and successful recruitment. Therefore the provisioning of eggs with antioxidants may be an important driver of life history strategies because they play a critical role in preventing damage from reactive oxygen species to macromolecules. In this study, a suite of oxidative stress biomarkers was measured in the gonads and eggs of the sea urchin Evechinus chloroticus exposed to polycyclic aromatic hydrocarbons (PAHs). Links between oxidative stress markers and core components of fitness including fecundity, gamete quality and maternal transfer of antioxidants were assessed. Experimental induction of oxidative stress was achieved via exposure to a mix of four PAHs over a 21-day period. In PAH exposed individuals, we observed a significant upregulation of the antioxidant defence and detoxification enzymes SOD, CAT, GR, GPx and GST, as well as a greater pool of the non-enzymatic antioxidant glutathione in gonad tissue and eggs. In contrast, glutathione redox status was not affected by PAH exposure, with the percentage of reduced glutathione remaining at approximately 80% in both gonad tissue and released eggs. PAH-exposed adults experienced greater than three- and five-fold increases in oxidative protein and lipid damage, respectively, in gonad tissue. In contrast, eggs maintained low levels of damage, not differing from baseline levels found in eggs released from PAH-naïve mothers. PAH exposure also resulted in a 2-fold reduction in fecundity of reproductively mature females but no significant alteration to egg diameter. Although PAH-exposed females released fewer eggs, successful fertilisation of those eggs was slightly enhanced with average rates ranging from 90–99% in comparison to 76–90% in control eggs. Early-stage offspring reflected maternal antioxidant status with populations derived from PAH-exposed mothers demonstrating significantly higher antioxidant levels than those derived from PAH-naïve mothers. This maternally inherited protection enhanced the capacity of embryos to minimise oxidative damage to lipids and proteins during early development but, despite this, did not reduce the proportion of morphological abnormalities in the population. Overall, these findings indicate that when faced with short-term contaminant stress E. chloroticus has the capacity to trade high reproductive output during a spawning event for a greater antioxidant investment in eggs. However, this production of potentially more resilient offspring did not translate to a fitness gain, at least for the early larval stages in the present experimental conditions.

The reproductive cycle of the sea urchin Lytechinus variegatus (Echinodermata: Echinoidea) in southern Brazil

Lytechinus variegatus (Lamarck) is a common echinoid found on the Atlantic coast of America from North Carolina to southern Brazil and their populations inhabit sub littoral shallow-water environments. This research examined some aspects of reproduction in the southern limit of distribution of the species. A total of 86 adult individuals of L. variegatus (50.8 to 77.0 mm test diameter) were manually collected from September 2000 to September 2001 along the unconsolidated bottoms at the eurihaline sector of Paranagua Bay (48° 19’ W - 25° 35’ S) for histological characterization of gametogenesis, sex ratio and gonadal index (GI) evaluation. This population showed a synchronicity in maturation and spawning events (autumn and winter respectively), with a 1:1 sex ratio (χ2 = 2.57, df = 7, p < 0.05). The GI increase was associated with storage of nutritional resources periods (resting stages and proliferation) that occurred between late winter and spring. Biometric analyzes indicated a greater investment in size and/or quantity of gametes between late spring and summer, when it was possible to observe mature sperm occupying on average 63.9 % of the follicular lumen and oocytes reaching values of 70.0 to 75.0 μm. Mature oocyte mean size is the highest diameter of those developed by other regular echinoids in the same latitude. However, the average diameter of mature oocytes of L. variegatus in the southern limit of its distribution was lower than the values recorded for the northern hemisphere.

Hypoxia induces miR-210, leading to anti-apoptosis in ovarian follicular cells of marine medaka Oryzias melastigma

Hypoxia is a major global problem that impairs reproductive functions and reduces the quality and quantity of gametes and the fertilization success of marine fish. Nevertheless, the detailed molecular mechanism underlying hypoxia-induced female reproductive impairment remains largely unknown. There is increasing evidence that miRNA is vital in regulating ovarian functions and is closely associated with female fertility in humans. Certain miRNAs that regulate apoptotic genes can be induced by hypoxia, resulting in cell apoptosis. Using primary ovarian follicular cells of the marine medaka, Oryzias melastigma, as a model, we investigated the response of miR-210 to hypoxic stress in ovarian tissues to see if it would interrupt reproductive functions. A significant induction of miR-210 was found in primary ovarian follicular cells exposed to hypoxia, and gene ontology analysis further highlighted the potential roles of miR-210 in cell proliferation, cell differentiation, and cell apoptosis. A number of miR-210 target apoptotic genes, including Deleted in liver cancer 1 protein (DLC1), STE20-like serine/threonine-protein kinase (SLK), tumor necrosis factor receptor superfamily member 10b (TNFRSF10B), RNA binding motif protein 25 (RBM25), and Ubiquitin-specific-processing protease 7 (USP7), were identified. We further showed that ectopic expression of miR-210 would result in down-regulation of these apoptotic genes. On the other hand, the inhibition of miR-210 promoted apoptotic cell death and the expression of apoptotic marker – caspase 3 in follicular cells under hypoxic treatment, supporting the regulatory role of miR-210 in ovarian cell apoptosis. This study provides new insights on how hypoxia induces miR-210, leading to anti-apoptosis in ovarian follicular cells in fish, which is fundamentally important in environmental sciences and reproductive biology.

Sex-specific patterns of aging in sexual ornaments and gametes.

Sex differences in age-dependent mortality and reproductive success are predicted to drive the evolution of sexually dimorphic patterns of reproductive investment over life. However, this prediction has not been fully explored because it is difficult to measure primary and secondary sexual traits over the life spans of males and females. Here we studied a population of fowl, Gallus gallus, to gain longitudinal data on a sexual ornament (the comb), quantity of gametes produced, and gamete quality (sperm velocity and egg mass) of males and females. Our results reveal pronounced differences between the sexes in age-specific patterns of reproductive investment. In males, comb size decreased linearly with age, high sperm quality early in life was associated with reduced sperm quality late in life, and high sperm production was related to early death. In contrast, female comb size and egg mass were maximized at intermediate ages, and fecundity was independent of life span. Finally, the way traits were related in males did not change over life, whereas in females the association between fecundity and comb size changed from positive to negative over the lifetime of a female, indicating that aging may lead to trade-offs in investment between traits in females. These results show that males and females differ in reproductive investment with age, in terms of both the expression of individual traits and their phenotypic covariance.

Germ Cell Differentiation from Pluripotent Cells

Infertility is a medical condition with an increasing impact in Western societies with causes linked to toxins, genetics, and aging (primarily delay of motherhood). Within the different pathologies that can lead to infertility, poor quality or reduced quantity of gametes plays an important role. Gamete donation and therefore demand on donated sperm and eggs in fertility clinics is increasing. It is hoped that a better understanding of the conditions related to poor gamete quality may allow scientists to design rational treatments. However, to date, relatively little is known about human germ cell development in large part due to the inaccessibility of human development to molecular genetic analysis. It is hoped that pluripotent human embryonic stem cells and induced pluripotent stem cells may provide an accessible in vitro model to study germline development; these cells are able to differentiate to cells of all three primary embryonic germ layers, as well as to germ cells in vitro. We review the state of the art in germline differentiation from pluripotent stem cells.

Manufacturing and Regenerating of Gametes

The decline of human fecundability stems from compromised quality and reduced quantity of gametes. The age-related female infertility and spermatogenic failure have been the major obstacle to overcome in ART with only limited success unless donated gametes are used. I review the different approaches to manufacturing and regenerating gametes. Attempts of nuclear transplantation for preventing oocyte aneuploidy thereby enhancing the developmental competence or for inducing haploidization of somatic cell nuclei aiming to generate oocytes and spermatozoa are explored by highlighting advantages and limitations of these strategies. In addition, approaches to differentiate precursor cells or pluripotent stem cells to their progenies or mature gametes are revisited. Finally, I also report preliminary data on enhancing the reproductive performance of a single spermatozoon by male genome cloning utilizing micromanipulation techniques.

Reproductive allocation in exploited lake whitefish (Coregonus clupeaformis) and walleye (Sander vitreus) populations

We examined age-related changes in energetic status and reproductive effort of lake whitefish (Coregonus clupeaformis) and walleye (Sander vitreus) populations in Lakes Winnipeg and Ontario. We predicted, based on life history theory, that both species would exhibit declines in somatic energy stores and increases in the proportion of their energy reserves allocated to reproduction as they aged. These predicted trends were evident for walleye but not for lake whitefish, and the contrast between species was most pronounced for females. Walleye devoted an increasingly larger proportion of their body lipids to gonad development as they got older whereas lake whitefish devoted an increasingly smaller proportion. Between-species differences for some reproductive traits, particularly gonad size (GSI) and relative fecundity, were not consistent between the two lakes. Lake whitefish follow a strategy of lower relative fecundity, larger eggs, and lower egg lipid content compared to walleye. Differences between these species in the gamete quantity and quality of different age classes suggest that age-structured population models parameterized for one species should be applied to other species with caution.

Chronic zebrafish low dose decabrominated diphenyl ether (BDE-209) exposure affected parental gonad development and locomotion in F1 offspring

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants around the world. Because of large production volumes, widespread usage and persistence, PBDEs are now ubiquitous environmental pollutants detected in a wide variety of environment media and human samples and therefore pose a significant public health concern. Deca-PBDE (BDE-209) is the only commercial PBDE mixture still allowed for use at present, and has been recently detected at high levels in human samples. However, few studies explore its effect on development, reproduction or neurobehavior with animal models. In particular, studies with long-term chronic exposure at relatively low doses are lacking. In this study, we utilize the zebrafish model to explore the developmental, reproductive, and behavioral toxicities associated with long-term chronic exposure to deca-PBDE (BDE-209). Our findings revealed that long-term chronic exposure to low dose of deca-BDE (ranging from 0.001 to 1 μM) affected overall fitness (measured by condition factor), gonad development, male gamete quantity and quality in F0 parental fish. For F1 offspring without continuous exposure to BDE-209, parental BDE treatment led to delayed hatch and motor neuron development, loose muscle fiber, slow locomotion behavior in normal conditions, and hyperactivity when subjected to light-dark photoperiod stimulation. In conclusion, parental chronic low dose BDE-209 exposure not only affects F0 growth and reproduction, but also elicits neurobehavior alternations in F1 offspring.

Sexing pollen reveals female bias in a dioecious plant

* Information on angiosperm sex ratios has largely been restricted to surveys of flowering individuals. These often deviate from equality, with male bias more commonly reported. Female-biased sex ratios are concentrated in a few taxa and have been linked to the possession of heteromorphic sex chromosomes and bias introduced during the gametophytic stage of the life cycle. It has been proposed that differences in gamete quantity and quality could give rise to female bias, although there is no direct evidence with which to evaluate this possibility. * Here, we use flow cytometry to investigate microgametophytic 'sex ratios' in a flowering plant. We demonstrate that differences in DNA content between the sexes in Rumex nivalis, a species with heteromorphic sex chromosomes, make it possible to distinguish female- vs male-determining pollen nuclei. * We found a small but significant female bias in microgametophytes produced by males (mean 0.515) with significant variation among family means (range 0.463-0.586), and 18 of 22 families averaging > 0.50. * The observed female bias at the gametophytic stage of the life cycle is consistent with the direction of bias previously reported for seeds and vegetative and reproductive plants in wild populations of R. nivalis, but is insufficient to fully explain the degree of bias.

Reproductive Performance of Growth-Enhanced Transgenic Coho Salmon

The reproductive performances of growth-enhanced transgenic, hatchery, and cultured nontransgenic coho salmon Oncorhynchus kisutch were examined to investigate the consequences of reproductive interaction between growth hormone (GH)–transgenic fish and wild fish that may occur if transgenic salmon escaped into the natural environment. We examined adult morphological phenotypes, gamete quantity and quality, in vitro offspring production, courtship and spawning behavior, male competitive behavior, and transgene transmission to offspring. Transgenic, hatchery, and cultured nontransgenic fish required 2, 3, and 3 or 4 years, respectively, to reach sexual maturation. No differences in male gamete quantity or in vitro offspring production were observed. Transgenic females were more fecund than hatchery females but had smaller eggs. Fewer transgenic females spawned than hatchery females under experimental conditions, and transgenic females displayed consistently low levels of courtship behavior. In noncompetitive trials, there were no differences in the courtship behavior of transgenic and hatchery males; during competition with hatchery males, however, transgenic males failed to spawn and displayed less courtship and competitive behavior. Cultured nontransgenic salmon also displayed reduced spawning capacity relative to hatchery salmon, indicating that the effects observed in transgenic salmon may arise in part from being reared in the culture environment and highlighting the difficulty in using laboratory-reared transgenic fish to assess reproductive fitness because of the strong genotype–environment interactions. As long as wild-reared transgenic fish are unavailable, exact determinations of reproductive fitness will be difficult. However, these studies have shown that in a simulated natural environment, growth-enhanced transgenic coho salmon do display courtship behavior and can spawn, producing viable transgenic offspring. The findings suggest some capacity exists for the natural transmission of transgenes to populations arising from reproductive interaction, which could occur during first contact between escaped cultured transgenic fish and wild conspecifics.

Reproductive cycles in littoral populations of Choromytilus meridionalis (Kr.) and Aulacomya ater (Molina) with a quantitative assessment of gamete production in the former

Changes in ovary weight and ovary smears of Choromytilus meridionalis (Kr.) and Aulacomya ater (Molina) showed the breeding season to extend throughout the spring and summer months (Aug.-Feb.). Release of gametes was intermittent with regeneration of the gonad after peak spawning periods. Populations spawned synchronously or asynchronously with an average of 50% of individuals spawning at any one time. The end of the breeding season was marked by gonad depletion and resorption of gametes. Gametogenesis followed rapidly and large quantities of reserve material were not deposited in the mantle during the winter months as in Mytilus edulis. The False Bay population of Choromytilus meridionalis has predominantly synchronous spawning and gamete production for two breeding seasons was calculated. The quantity of gametes released varied annually and was not significantly different in males and females. Mean gamete production was calculated as 1.17 × standing crop expressed as dry flesh weight, or 1.33 × energy value of the standing crop per annum.

GONAD DEVELOPMENT AND DISCHARGE OF SPAWN IN OYSTERS OF LONG ISLAND SOUND

Previous articleNext article No AccessJournal ArticleGONAD DEVELOPMENT AND DISCHARGE OF SPAWN IN OYSTERS OF LONG ISLAND SOUNDVICTOR L. LOOSANOFFVICTOR L. LOOSANOFFU. S. Bureau of Commercial Fisheries, Biological Laboratory, Milford, Connecticut Search for more articles by this author U. S. Bureau of Commercial Fisheries, Biological Laboratory, Milford, ConnecticutPDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Biological Bulletin Volume 129, Number 3December 1965 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.2307/1539732 Views: 13Total views on this site Citations: 1Citations are reported from Crossref Copyright © 1965 by Marine Biological LaboratoryPDF download Crossref reports the following articles citing this article:PAUL F. HAYES and R. WINSTON MENZEL THE REPRODUCTIVE CYCLE OF EARLY SETTING CRASSOSTREA VIRGINICA (GMELIN) IN THE NORTHERN GULF OF MEXICO, AND ITS IMPLICATIONS FOR POPULATION RECRUITMENT, The Biological Bulletin 160, no.11 (Sep 2016): 80–88.https://doi.org/10.2307/1540902

ヒトエグサの配偶子放出における光の影響

It has been determined that exposure to light following a period of darkness activates the immobile gametes in the cells of Monostroma. This report deals with a correlation between such activation and the light conditions concerned.1. After a sufficient period of darkness, exposure to light appears to act as a trigger agent.2. The length of darkness necessary to cause liberation becomes shorter as the “maturity” of the gametes advances, and finally activation can occur without exposure to darkness.3. The necessary duration of darkness is not additive.4. When the necessary dark period is interrupted by exposure to light, its effect is cancelled.5. Light periods following exposure to darkness: After a sufficient exposure to darkness, liberation was induced by 1 sec. irradiation, while insufficient dark periods required longer exposures to light. The condition of 1hr. exposure to darkness followed by 1 sec. light becomes sufficient to induce activation as the gametes become more “mature”. The quantity of gametes liberated after sufficient exposure to dark is proportional to the light intensity and length of light period within certain limits.6. Light of wave length shorter than 500mμ is necessary for liberation. Light of wave length that was ineffective for liberation had an effect similar to that of darkness. Light of short wave length was effective in nullifying the effect of a preceding dark period.From the above facts, it is suggested that in Monostroma the reaction which leads to activation of the gametes consists of two parts. The first reaction proceeds at a suitable temperature in the absence of blue light, and when this reaction is complete, the second reaction is induced by momentary exposure to blue light.