Ovarian Lipid Research Articles

An Unprecedented Occurrence of Δ5,9- and Δ9,15-Dienoic Fatty Acids in Ovaries of the Archaeogastropod Limpet Cellana toreuma.

A detailed structural diversity of dienoic fatty acids (FA), including non-methylene-interrupted dienoic FA, of triacylglycerols and polar lipids in ovaries of Cellana toreuma was clarified for the first time by using capillary gas chromatography-mass spectrometry of their 3-pyridylcarbinol esters and argentation thin-layer chromatography. Interestingly, in addition to 5,9-octadecadienoic (18:2Δ5,9), 5,9-eicosadienoic (20:2Δ5,9), 5,9-heneicosadienoic (21:2Δ5,9), 5,9-docosadienoic (22:2Δ5,9), 5,9-tricosadienoic (23:2Δ5,9), and 5,9-tetracosadienoic (24:2Δ5,9) acids, previously identified in ovaries of C. grata, rare FA 5,9-hexadecadienoic (16:2Δ5,9), 5,9-nonadecadienoic (19:2Δ5,9), and 21-methyl-5,9-docosadienoic (iso 23:2Δ5,9) were newly recognized in ovaries of C. toreuma. Detectable amounts of four Δ9,15-dienoic FA were present in the ovary lipids. The FA identified were one novel 9,15-heneicosadienoic (21:2Δ9,15) acid and known 9,15-docosadienoic (22:2Δ9,15), 9,15-tricosadienoic (23:2Δ9,15), and 9,15-tetracosadienoic (24:2Δ9,15) acids. The findings help to explain the broad evidence of the structural diversity in marine gastropods and suggest biomarkers to evaluate marine food web relations.

Effect of different rearing conditions on body lipid composition of greater amberjack broodstock (Seriola dumerili)

The aim of this study was to assess the effect of two rearing conditions: outdoor environment with great volume tanks (500 m3) and low stocking density (~0.4 kg m−3); and indoor environment with smaller volume tanks (10 m3) and higher stocking density (~5 kg m−3), on muscle, liver and ovary lipid composition of Seriola dumerili broodstock born in captivity. The rearing conditions tested seem to affect the pattern of lipid body deposition in broodstock fish of S. dumerili, increasing the muscle and liver triacylglycerides (TG) accumulation of fish kept under indoor conditions, probably due to reduced energy expenditure in swimming, with some variations in the fatty acid profile that may respond to the differences in the culture conditions tested. No significant differences were found for Gonadosomatic Index (GSI) or ovary lipid deposition between groups in this study, which may suggest that the conditions tested do not have a major effect on ovary development. However, one season later the females kept under outdoor conditions released eggs spontaneously, whereas those kept under indoor conditions did not spawn, suggesting that the conditions tested actually have an effect on the broodstock's reproductive fitness. More studies are needed in order to evaluate whether the conditions tested have or not any influence on ovary development.

Nutrient effects of broodstocks on the larvae in Patinopecten yessoensis

Patinopecten yessoensis is a commercial valuable species. This study deals with the effect of nutrient effects of the broodstock (mainly ovaries) on the larvae. Concentrations of total carbohydrate, total protein and total lipid in the gonads of P. yessoensis from three Hatcheries (Hatchery 1, Hatchery 2, and Hatchery 3) were determined before and after spawning. The relationship between the nutrient concentration in ovaries before spawning (BC) and that of larvae (LC) was assessed as well as the change in nutrient levels in ovaries after spawning (DC). Results indicate that the BC of total carbohydrate (7.66%) and total lipid (14.48%) in ovaries were significantly higher than in testes (5.20%, 5.20% respectively), whereas the BC of total protein in the ovaries was lower (61.76%) than in the testes (81.67%). The different gonadal composition suggests the different nutrient demands between male and female broodstocks in breeding season. Patinopecten yessoensis gonads contained a higher proportion of lipids, in comparison to other bivalves, which might be a response to the low ambient water temperatures. Further analysis of fatty acids showed that the concentrations of n-3PUFA, EPA and DHA in larvae (LC) were positively correlated with BC and DC, indicating the significant nutrient influence of broodstocks on the larvae. As these fatty acids are important in metabolism, and have been demonstrated to be influential to the viability of the larvae, larval growth and the settlement, spat growth, and juvenile survival in many bivalves, they could possibly be used as indexes to evaluate, and predict condition of broodstocks and larvae.

187 OVARIAN CYCLE LIPID DYNAMICS REVEALED BY DESI-MS IMAGING AND MORPHOLOGICALLY-DRIVEN MULTIVARIATE STATISTICS

Understanding the role of lipid metabolism in ovarian physiology is crucial for the progression of reproductive biotechnology. The aim in this work was to explore the lipid composition and dynamics of ovarian tissue, specifically the stroma, follicles, and corpora lutea. Desorption electrospray ionization–mass spectrometry (DESI-MS), an ambient ionization technique, was applied in this investigation, acquiring chemical and spatial information simultaneously. A morphologically-friendly solvent, dimethylformamide-acetonitrile (1 : 1), was used for DESI-MS imaging which allowed for ovarian lipid characterisation and subsequent staining (hematoxylin and eosin) providing morphological information. By this approach, regions-of-interest (ROI) were selected from bovine (n = 8), swine (n = 3), and mice (n = 5) ovaries (including pre-pubescent and cycling adults) based on the stained morphological structures. ROI for stroma (n = 54), follicles (n = 89), and corpora lutea (n = 61) were selected and chemically profiled. Tissue sections (20 μm) were thaw mounted onto glass microscope slides and stored at –80°C until analysis. A linear ion trap mass spectrometer equipped with a custom DESI-MS imaging stage was operated in the negative ion mode (m/z 200 to 1000). A 300 × 300 µm pixel size was used in DESI-MS imaging of ovarian tissue. Hyperspectral DESI images were reconstructed and processed by principal component analysis (PCA) that allowed visualisation of relationships among spatial (i.e. morphology) and chemical features. Ions indicated by PCA were analysed using univariate analysis (ANOVA), supporting the significance of particular lipids between morphological structures, e.g. adrenic acid (P = 1.7 × 10–8) and m/z 836 (P = 8.9 × 10–9) between corpora lutea and follicles. All morphological structures could be differentiated by multivariate statistics (>90% prediction rate) independent of the species, indicating conserved lipid constitution. Smaller differences in the lipid profiles were noted between species, poly-ovulatory and mono-ovulatory species, and reproductive maturation. A large variety and abundance of lipids was observed in corpora lutea and follicles, where steroidogenesis is a prominent physiological activity. Additional insight into ovarian physiology was gained with the detection of arachidonic and adrenic acid. The spatial relationship of arachidonic and adrenic acid with the corpora lutea – the former is a known prostaglandin precursor and key signalling molecule in steroidogenesis regulation and the latter is metabolized in the prostaglandin pathway by the same enzymes – suggests the latter may also have a role in steroidogenesis regulation, previously unseen in ovarian physiology. DESI-MS imaging with morphologically-driven statistical analysis proved efficient in relating and interpreting the chemical and morphological features. This methodology can by further applied to unravel complex ovarian-related physiological mechanisms and to other physiological and physiopathological models.

The role of ovarian steroids in reproductive plasticity in Hoplias malabaricus (Teleostei: Characiformes: Erythrinidae) in tropical reservoirs with different degrees of pollution

Chemicals in aquatic environments may lead to impairment of fish reproduction, but some species display plasticity levels to survive and reproduce in such localities. We investigated the reproductive cycle in a teleost species, Hoplias malabaricus, which inhabits a variety of environments with different degrees of pollution. Adult females were sampled at two locations in São Paulo State (Brazil), the reference Ponte Nova (PN) reservoir and the polluted Billings (BIL) reservoir. Metabolic and endocrine processes were analyzed throughout the annual cycle with special attention to ovarian histology, gonadosomatic index (GSI), fecundity, ovarian energetic substrates and plasma steroids analyses, in addition to physical and chemical analyses of the water. Pollutants were frequent in BIL but not in PN. The GSI, including the predominance of vitellogenic oocytes, was higher in spring and summer in both locations, but the oocyte recruitment dynamics was different. During winter, females from BIL presented vitellogenic oocytes and high levels of 11-ketotestosterone, which indicated precocity in the vitellogenic phase in relation to the females from PN. In animals from PN, high deposition of lipids occurred in the ovaries. However, plasma estradiol levels did not vary throughout the annual cycle. In animals from BIL, plasma estradiol levels peaked during the summer, but the ovarian lipid content remained unchanged throughout the year. The data suggest that the presence of pollutants cause various endocrine and metabolic responses and especially affects reproductive plasticity, which could explain why H. malabaricus survives under unfavorable environments.

Trade-off of ovarian lipids and total body lipids for fecundity and starvation resistance in tropical populations of Drosophila melanogaster.

In Drosophila melanogaster, clines of starvation resistance along a latitudinal gradient (south to north) have been reported in India, which matched with their cline for total body lipids (TL ). Nevertheless, producing too many reserves is likely to be costly and a trade-off might exist with life-history traits. Previous studies on starvation resistance and life-history traits of D.melanogaster have mainly focused on quantification of total body lipids, instead of separating ovarian lipids from total body lipids. In the present study, we have quantified absolute ovarian lipids (OL ) versus absolute body lipids excluding ovarian lipids (BL ) and examined associations with fecundity as well as starvation resistance in two latitudinal populations (8.34 vs. 32.43°N) of D.melanogaster. Firstly, we observed a trade-off between BL and OL that matched the trade-off of starvation resistance, longevity versus fecundity and development time in latitudinal populations of D.melanogaster. Southern populations had higher starvation resistance, more BL and lesser OL, whereas northern populations had enhanced fecundity, OL and lesser BL . Secondly, within population, starvation resistance also correlated with BL , and fecundity with OL . However, there was no correlation between starvation resistance and OL . Moreover, there was utilization of BL and nonutilization of OL under starvation stress. Therefore, resources invested for fecundity in the form of OL were independent of evolved starvation resistance in D.melanogaster. Our results suggest that a common pool of energy storage compounds (lipids) are allocated differentially between fecundity and starvation resistance and are consistent with Y-model of resource allocation.

Ovarian nutritional resources during the reproductive cycle of the hematophagous Dipetalogaster maxima (Hemiptera: Reduviidae): focus on lipid metabolism.

In this study, we have analyzed the changes of the ovarian nutritional resources in Dipetalogaster maxima at representative days of the reproductive cycle: previtellogenesis, vitellogenesis, as well as fasting-induced early and late atresia. As expected, the amounts of ovarian lipids, proteins, and glycogen increased significantly from previtellogenesis to vitellogenesis and then, diminished during atresia. However, lipids and protein stores found at the atretic stages were higher in comparison to those registered at previtellogenesis. Specific lipid staining of ovarian tissue sections evidenced remarkable changes in the shape, size, and distribution of lipid droplets throughout the reproductive cycle. The role of lipophorin (Lp) as a yolk protein precursor was analyzed by co-injecting Lp-OG (where OG is Oregon Green) and Lp-DiI (where DiI is 1,10-dioctadecyl-3,3,30,30-tetramethylindocarbocyanine) to follow the entire particle, demonstrating that both probes colocalized mainly in the yolk bodies of vitellogenic oocytes. Immunofluorescence assays also showed that Lp was associated to yolk bodies, supporting its endocytic pathway during vitellogenesis. The involvement of Lp in lipid delivery to oocytes was investigated in vivo by co-injecting fluorescent probes to follow the fate of the entire particle (Lp-DiI) and its lipid cargo (Lp-Bodipy-FA). Lp-DiI was readily incorporated by vitellogenic oocytes and no lipoprotein uptake was observed in terminal follicles of ovaries at atretic stages. Bodipy-FA was promptly transferred to vitellogenic oocytes and, to a much lesser extent, to previtellogenic follicles and to oocytes of ovarian tissue at atretic stages. Colocalization of Lp-DiI and Lp-Bodipy-FA inside yolk bodies indicated the relevance of Lp in the buildup of lipid and protein oocyte stores during vitellogenesis.

Low-density lipoprotein receptor affects the fertility of female mice.

Low-density lipoprotein receptor (LDLR) has been demonstrated to play a central role in lipoprotein metabolism, with Ldlr-deficient (Ldlr(-/-)) mice developing severe dyslipidemia. In the present study we investigated whether Ldlr knockout could harm female reproduction and explored the mechanisms involved. The results indicate that although the number of litters born to Ldlr(-/-) mice did not differ significantly from that born to controls, the number of pups per litter was significantly lower in the former group. Interestingly, although Ldlr(-/-) mice were obese, the weight of their ovaries was lower than that in control mice. Serum cholesterol levels was significantly higher in Ldlr(-/-) mice than in their wild-type counterparts. In contrast, there were significant decreases in cholesterol, triglyceride and total lipid levels in ovaries of Ldlr(-/-) mice. Both ovarian lipid deposition, as detected by Oil red O staining, and lipid droplets, as evaluated by transmission electron microscopy, supported decreased lipid levels in ovaries from Ldlr(-/-) mice. In addition, Ldlr(-/-) mice had fewer ovarian follicles, more atretic follicles, lower oestrogen levels and spent significantly less time in oestrus than did the controls. Superovulation assays indicated immature Ldlr(-/-) mice ovulated fewer ova than controls. These results indicate that lack of Ldlr results in dyslipidaemia and poor fertility.

Female reproductive aging is master-planned at the level of ovary.

The ovary receives a finite pool of follicles during fetal life. Atresia remains the major form of follicular expenditure at all stages since development of ovary. The follicular reserve, however, declines at an exponential rate leading to accelerated rate of decay during the years preceding menopause. We examined if diminished follicle reserve that characterizes ovarian aging impacts the attrition rate. Premature ovarian aging was induced in rats by intra-embryonic injection of galactosyltransferase-antibody on embryonic day 10. On post-natal day 35 of the female litters, either a wedge of fat (sham control) or a wild type ovary collected from 25-day old control rats, was transplanted under the ovarian bursa in both sides. Follicular growth and atresia, and ovarian microenvironment were evaluated in the follicle-deficient host ovary and transplanted ovary by real time RT-PCR analysis of growth differentiation factor-9, bone morphogenetic protein 15, and kit ligand, biochemical evaluation of ovarian lipid peroxidation, superoxide dismutase (SOD) and catalase activity, and western blot analysis of ovarian pro- and anti-apoptotic factors including p53, bax, bcl2, and caspase 3. Results demonstrated that the rate of follicular atresia, which was highly preponderant in the follicle-deficient ovary of the sham-operated group, was significantly prevented in the presence of the transplanted ovary. As against the follicle-deficient ovary of the sham-operated group, the follicle-deficient host ovary as well as the transplanted ovary in the ovary-transplanted group exhibited stimulated follicle growth with increased expression of anti-apoptotic factors and down regulation of pro-apoptotic factors. Both the host and transplanted ovaries also had significantly lower rate of lipid peroxidation with increased SOD and catalase activity. We conclude that the declining follicular reserve is perhaps the immediate thrust that increases the rate of follicle depletion during the final phase of ovarian life when the follicle reserve wanes below certain threshold size.

Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes

The effect of male accessory gland substances on female reproductive physiology has been previously described as “activating” egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main questions: (1) Do mating and male accessory gland substances affect ovarian physiology and alter markers of oocyte quality during the previtellogenic resting stage? (2) Does the male accessory gland contain JH III and is JH III transferred to the female during copulation? (3) Finally, does the nutritional history of the male affect the amount of JH III transferred to the female and alter reproductive output? By answering these questions it is clear that male mosquitoes are able to alter the female’s resource allocation priorities towards reproduction by transferring JH III during copulation; reducing the rate of previtellogenic resorption and increasing the amount of stored ovarian lipids. These changes improve an individual follicle’s likelihood of development after a blood meal. In addition, males maintained under better nutritional conditions make and transfer more JH III, prevent more follicular resorption and realize higher fecundities than other males. Together these results illustrate one mechanism behind the “activating” effect of mating described as well as the role sugar feeding plays in male mosquitoes.

Biochemical composition dynamics of the ovaries and hepatopancreas at different physiological stages of the female marine crab, Charybdis japonica

The present study investigated the biochemical composition, including the amino acids and fatty acids profiles of the ovaries and hepatopancreas of the female marine crab, Charybdis japonica (A. Milne-Edwards, 1861), at different physiological stages (immature, mature, spawning and abortion), together with the dynamic changes of the Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) during gonad development. A significant inverse relationship between GSI and HSI (R=−0.82; P<0.05) was recorded. The protein, total amino-acid (TAA), essential amino acid (EAA) and polyunsaturated fatty acid (PUFA) content and the ratio of n-3/n-6 in the ovaries were significantly higher than those in the hepatopancreas, while the content of moisture and saturated fatty acid (SFA) were lower. From immature to mature, the content of proteins and lipids in ovaries increased, and the content of carbohydrates decreased noticeably, while these tendencies in hepatopancreas were in the reverse order. A significant increase in the total amount of TAA and EAA in ovaries of mature stages was measured; the content of all amino acids increased, except for arginine, which decreased slightly. The content of PUFA in the ovaries increased with maturation, while the content of monounsaturated fatty acid (MUFA) decreased. Abundant threonine, methionine, leucine and C22:6n-3 (docosahexaenoic acid, DHA) were observed in the hepatopancreas of spawning crabs. Compared to spawning crabs, the content of protein and ash in the hepatopancreas of aborting crabs decreased significantly, while the carbohydrates content rose, and that the content of TAA, EAA and PUFA in the ovaries and hepatopancreas of aborting crabs were all lower, especially the amount of n-3 fatty acids in hepatopancreas, which decreased substantially, including DHA from 9.02% to 3.25%, and eicosapentaenoic acid (EPA) from 0.93% to 0.44%.

Fishing and fecundity: The impact of exploitation on the reproductive potential of a deep-water fish, orange roughy (Hoplostethus atlanticus)

To assess the impact of exploitation on the fecundity and reproductive potential of orange roughy, historic biological data from when exploitation began (1987–1992) is compared with a current day assessment (2010) of the eastern Tasmanian stock. Findings highlight that fecundity was negatively related to stock size (r2=0.95, F=80.11, P<0.05), with length standardised fecundity increasing from 41,145±1363 in 1992 to 59,236±1047 eggs in 2010. This density dependent increase suggests that from the onset of the fishery (1987) length standardised fecundity has increased by 73%. Modelling this increase based on the 2006 stock assessment showed that the female spawning stock biomass was at 19% of virgin levels, whereas the total reproductive potential was markedly higher and estimated to be at 32% of virgin levels. The biological mechanisms of this compensatory effect were also investigated and showed fecundity was not related to ovarian atresia levels but was positively related to body condition, liver condition and ovarian lipid levels. The implications of these findings for stock recovery and management are discussed and suggest that the stock is in a better position to recover from overexploitation than would be expected if only spawning stock biomass were considered

Effect of preventive acupuncture and moxibustion on hypothalamus and ovarian leptin and blood lipid levels in menopausal rats

Objective To observe the changes of hypothalamus, ovarian leptin levels and blood lipid in 12-month-old rats with natural menopause, and the effect of preventive acupuncture and moxibustion at Guanyuan (CV 4). To explore the impact of preventive acupuncture and moxibustion on the internal environment of early menopause disorder.

Folate forever- all methyl group donations welcome!

Folate forever- all methyl group donations welcome!

Tributyltin exposure causes lipotoxicity responses in the ovaries of rockfish, Sebastiscus marmoratus

Tributyltin (TBT) is a well-studied endocrine disruptor in mollusks and fishes. Recently, TBT is also recognized as a metabolic disruptor. Since abnormal lipids metabolism can induce negative effects on reproduction, the present study was designed to investigate the effects of TBT on ovarian lipid accumulation and testosterone esterification in rockfish (Sebastiscus marmoratus). After exposure for 48d, there was a decrease of neutral lipid droplets in the ooplasm of ovaries. Exposure has also induced lipotoxicity responses in the ovaries, which shown as an increase of interstitial ectopic lipid accumulation and total lipids. The decrease of serum triiodothyronine and thyroxine concentrations might be responsible for the lipotoxicity responses. In addition, the percentage of testosterone in an esterified form was significantly decreased in the ovaries by TBT exposure, which might be a mechanism by which free testosterone levels increased. The accumulation of ectopic lipids and increase of free testosterone levels in the ovaries might impact ovarian functions and oocyte development in fish. These results strongly indicate that TBT exposure can influence reproductive functions of rockfish through lipotoxic mechanism.

Modification of essential fatty acid composition in broodstock of cultured European eelAnguilla anguillaL

Farmed eels had lower levels of arachidonic acid (20:4 n-6) (ARA) and higher ratios of eicosapentaenoic acid (20:5 n-3) (EPA):ARA compared to wild European eels collected from the Baltic Sea and southern Norwegian coast. Eels fed a formulated feed (JD) with a distribution of essential fatty acids (EFA) resembling wild European eel were sampled after 0, 5, 10, 14 and 44 weeks of feeding to examine changes in fatty acid composition (FAC) in ovaries, visceral fat and muscle. The results showed a slow but steady incorporation of EFA. Lipids are incorporated in the oocytes early in oogenesis, and the leading cohort of oocytes is rich in lipid droplets before the onset of vitellogenesis. This indicates that feeding with optimized broodstock feeds should start early to allow the incorporation of EFA in the first cohort of oocytes. At least 14 weeks of feeding is required to change lipid EFA in broodstock eel to resemble EFA in the diet or in wild fish. After 44 weeks of feeding, ARA was significantly higher in the neutral lipids of ovaries (1.9%) compared to visceral fat (1.2%) or muscle (1.0%). EPA:ARA ratios decreased two- to threefold in all tissues examined during that time. ARA and docosahexaenoic acid (22:6 n-3) (DHA) had accumulated in ovarian polar lipids.

Novel Heneicosadienoic and Tricosadienoic Acid Isomers in Ovaries of Marine Archaeogastropods

To investigate unusual odd-chain fatty acids (FA) from gonads of archaeogastropods, limpets Cellana grata and Cellana toreuma, a subfraction enriched in FA with two double bonds extracted from the gonads was obtained by using argentation thin-layer chromatography. The resulting fraction was analyzed by using capillary gas chromatography-mass spectrometry of its methyl esters, 3-pyridylcarbinol esters and pyrrolidide derivatives. Six novel all-cis diene isomers were identified as 7,18-heneicosadienoic (21:2Δ7,18), 8,14-tricosadienoic (23:2Δ8,14), 9,15-tricosadienoic (23:2Δ9,15), 7,18-tricosadienoic (23:2Δ7,18), 9,18-tricosadienoic (23:2Δ9,18), and 9,20-tricosadienoic (23:2Δ9,20) acids. In the present study, the differences in the proportion of tricosadienoic acid isomers between the ovary lipids of C. grata and C. toreuma were recognized.

The changes of serum biochemical components during carp pituitary extract and HCG induced maturation of the female Japanese eel (Anguilla japonica)

Based on the gonadosomatic indexes (GSI) of different developmental ovary stages of the fe-male Japanese eel during carp pituitary extract and HCG induced maturation, the paper measured and analyzed six biochemical components of the serum, namely total protein (TP), triglycerides (TG), total cholesterol (TC), blood glucose (Glu), calcium (Ca) and phosphorus(P) by medical inspection methods. The results showed that the gonad of treatment group got matured gradually during 84 days with GSI in-creasing significantly to 46.32%±1.75% at the 12th injection; while GSI of the control group stayed at 2.45% ± 0.30%. There was no difference between the TP level of treatment group and control group (P 0.05) which remained relatively stable. However, the blood lipid displayed significant difference (P 0.05) until 56th day: TG and TC of the treatment group maintained a high level, averaged at (12.67 ± 2.83) mmol/L and (15.54 ± 3.01) mmol/L respectively; while control group kept a low level, averaged at (6.33 ± 4.14) mmol/L and (8.53 ± 3.30) mmol/L respectively. The Glu level of both groups carried on rising from a low level at the beginning. Correlation analysis indicated that there was significant negative correlations between TG and GSI in treatment group (r =?0.732, n=6, P 0.01). Significant correlations were found between Ca and GSI (r =0.961, n=6, P 0.01), P and GSI (r =0.775, n=6, P 0.01)in treatment group: as the growth rates of GSI, and the level of Ca and P increased dramatically from 28th day, while the control group stayed at a low level. It turned out that there is a close relationship between ovary development and lipid metabolism, and some inorganic ions (Ca, P) have played an important role in this process. Accord-ing to the nutrition requirement and metabolic rule of the female Japanese eel, it’s a new potential way to judge ovary developmental stages by measuring and analyzing the level of blood lipid or serum Ca and P.

Effects of polychaete extracts on reproductive performance of kuruma shrimp, Marsupenaeus japonicus Bate. – Part II. Ovarian maturation and tissue lipid compositions

A 32-day feeding trial was conducted to examine effects of marine polychaete extracts on ovarian maturation and tissue lipid compositions of Marsupenaeus japonicus. Three fractions extracted from polychaetes such as trichloroacetic-soluble (TSF), neutral lipids (NLF) and polar lipids (PLF) fractions at 0.5% (dry matter basis) were supplemented to a basal diet (BD). Frozen polychaetes (FPC) and BD were used as positive and negative controls, respectively. Each treatment with triplicate groups of ten unilaterally eyestalk-ablated wild caught females at early stages of ovarian development were fed test diets above once a day at 5:00pm with excess of pellet diets and 10% of biomass with FPC. The ovarian development was tracked every 4 days. The maximum ovary shadow ratios (OSR=ovary width×100/body width) were not significantly different among treatments. Ovarian maturation time (OMT), defined as the time elapsed for ovaries to develop from initial to maximum OSR, of NLF and FPC groups were significantly shorter than those of other groups. Maturation response (MR=proportion (%) of females achieving ovarian maturity within each treatment) had some distinctive trends during the course of the trial. The study also indicated that NLF was the most effective on M. japonicus ovarian maturation and followed by TSF. Phospholipids were dominant in the ovarian lipid compositions while contents of neutral lipids were relatively high in hepatopancreas in all diet groups. Hepatopancreatic and ovarian fatty acid profiles showed significant differences in proportions of some important fatty acids. Furthermore, this study demonstrated that formulated feed being fed solely was able to promote the ovarian maturation in kuruma shrimp broodstock.

Effects of reproductive stage and 11-ketotestosterone on LPL mRNA levels in the ovary of the shortfinned eel

To understand the dynamics of lipid uptake into the ovary and the potential role that lipoprotein lipase plays in this event, changes in LPL transcript abundance during oogenesis were measured in both wild-caught and pituitary homogenate-induced artificially maturing eels. Also, the effects of 11-ketotestosterone (11-KT) on LPL mRNA levels were investigated in vivo and in vitro. Normalized ovarian LPL transcript abundance increased as oogenesis advanced, and it rose particularly rapidly during midvitellogenesis, corresponding to pronounced increases in ovarian lipid deposits and LPL activity. Furthermore, LPL mRNA levels were dramatically increased following 11-KT treatment in vivo, findings that were reinforced as trends in ovarian tissue incubated in vitro. Ovarian LPL appears to be directly involved in the uptake of lipids into the eel ovary, an involvement that appears to be controlled, at least in part, by the androgen 11-KT.