Changes in lipid and fatty acid contents of gonad during the reproductive cycle of the Mediterranean swordfish Xiphias gladius

Swordfish Xiphias gladius is a large pelagic fish distributed worldwide and exploited for human consumption, however there is limited knowledge about its reproductive biology, especially regarding lipid dynamic in gonads. In teleost fish, reproductive success and offspring survival are associated to lipid availability for gamete synthesis. This study investigated the lipid composition, including lipid classes and fatty acids (FA) of cell membrane and reserve lipids (i.e., polar and neutral lipids, respectively; PL and NL), along female and male gonad development of a swordfish population from waters surrounding Corsica Island in the Mediterranean Sea. Overall, swordfish gonads contained <2% wet weight of total lipids, with testes and ovaries having similar fat content. Lipid classes and FA concentrations remained unchanged during testes maturation. However, concentrations of phosphatidyl choline (PL), triacylglycerol (NL), and some FA (16:0, 18:1n-9, and 22:6n-3) followed an "inverted U-shaped" relationship with the ovarian maturation. In both PL and NL, 22:6n-3 was the main polyunsaturated FA (>20% of total FA), while 20:5n-3 and 20:4n-6 were minor (3-6% of total FA) and varied little with maturation. 22:6n-3 and 18:1n-9 were selectively allocated to the ovarian maturation (increased in concentration and in proportion with maturation) until spawning. Finally, swordfish gonads might represent a good food source for humans given that 150 g of swordfish ovaries can cover the daily requirements in omega-3 for humans, but research on pollutants should also be conducted to evaluate their implications on the reproduction output of this species, and on the safety of swordfish gonads for human consumption.

Risk and benefit assessment of seafood consumption harvested from the Pertuis Charentais region of France

Seafood is well recognized as a major source of Long Chain n-3 Polyunsaturated Fatty Acids (LC n-3 PUFA, especially ecosapentaenoic acid, i.e. EPA and docosaheaxaenoic acid, i.e. DHA) and essential trace elements (As, Cu, Fe, Mn, Se, and Zn). It is also a source of non-essential trace elements (Ag, Cd, Hg, Pb) that can be deleterious for health even at low concentrations. Edible parts of sixteen species (fish, cephalopods, crustaceans and bivalves) of great importance in the Pertuis Charentais region, one of the main shellfish farming and fishing areas along the french coastline, were sampled in winter and analyzed to determine their fatty acid (FA) composition and trace element concentrations. Based on these analyses, a suite of indices was calculated to estimate risk and benefit of seafood consumption: the n-6/n-3 ratio, the atherogenic index, the thrombogenic index, the EPA + DHA daily recommended portion, as well as the maximum safe consumption. The results showed that fish contributed the most to LC n-3 PUFA supply, while bivalves and crustaceans were more beneficial in essential trace elements. Whatever the species, the concentrations of non-essential elements were not limiting for seafood consumption, as important amounts of the analyzed species can be eaten daily or weekly before becoming hazardous to consumers. Yet, concentrations of Hg in dogfish and seabass can become a concern for frequent seafood consumers (>three meals a week), confirming that varying seafood items is a key point for consumers to optimize the benefits of diverse seafood resources. Considering FA composition, whiting and pilchard are the most beneficial fish species for human diet, while surmullet was the least beneficial one. However, using an index integrating the relative risk due to Hg content, the surmullet appears as one of the most beneficial. This study provides a temporal shot of the quality of marine resources consumed in winter period in the studied area and highlights the complexity of a quantitative risk and benefit assessment with respect to the biochemical attributes of selected seafood.

A 13CO2 Enrichment Experiment to Study the Synthesis Pathways of Polyunsaturated Fatty Acids of the Haptophyte Tisochrysis lutea

The production of polyunsaturated fatty acids (PUFA) in Tisochrysis lutea was studied using the gradual incorporation of a ¹³C-enriched isotopic marker, ¹³CO₂, for 24 h during the exponential growth of the algae. The ¹³C enrichment of eleven fatty acids was followed to understand the synthetic pathways the most likely to form the essential polyunsaturated fatty acids 20:5n-3 (EPA) and 22:6n-3 (DHA) in T. lutea. The fatty acids 16:0, 18:1n-9 + 18:3n-3, 18:2n-6, and 22:5n-6 were the most enriched in ¹³C. On the contrary, 18:4n-3 and 18:5n-3 were the least enriched in ¹³C after long chain polyunsaturated fatty acids such as 20:5n-3 or 22:5n-3. The algae appeared to use different routes in parallel to form its polyunsaturated fatty acids. The use of the PKS pathway was hypothesized for polyunsaturated fatty acids with n-6 configuration (such as 22:5n-6) but might also exist for n-3 PUFA (especially 20:5n-3). With regard to the conventional n-3 PUFA pathway, Δ6 desaturation of 18:3n-3 appeared to be the most limiting step for T. lutea, “stopping” at the synthesis of 18:4n-3 and 18:5n-3. These two fatty acids were hypothesized to not undergo any further reaction of elongation and desaturation after being formed and were therefore considered “end-products”. To circumvent this limiting synthetic route, Tisochrysis lutea seemed to have developed an alternative route via Δ8 desaturation to produce longer chain fatty acids such as 20:5n-3 and 22:5n-3. 22:6n-3 presented a lower enrichment and appeared to be produced by a combination of different pathways: the conventional n-3 PUFA pathway by desaturation of 22:5n-3, the alternative route of ω-3 desaturase using 22:5n-6 as precursor, and possibly the PKS pathway. In this study, PKS synthesis looked particularly effective for producing long chain polyunsaturated fatty acids. The rate of enrichment of these compounds hypothetically synthesized by PKS is remarkably fast, making undetectable the ¹³C incorporation into their precursors. Finally, we identified a protein cluster gathering PKS sequences of proteins that are hypothesized allowing n-3 PUFA synthesis.

Post-mortem storage conditions and cooking methods affect long-chain omega-3 fatty acid content in Atlantic mackerel (Scomber scombrus)

Long-chain omega-3 fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) are health beneficial lipids found in high concentration in pelagic fishes, including Atlantic mackerel. While EPA and DHA are sensitive to oxidation during fish storage and processing, post-mortem degradation in the first hours following fish death is poorly documented. Here, we stored fish at two temperatures (2-4 °C and 18-20 °C) and monitored EPA + DHA content in dorsal fillet 6, 12 and 24 h after fish death and after cooking (grill or steam). Storage duration was the only influencing factor, and EPA + DHA loss was faster at 18-20 °C. Six hours after fish death, EPA + DHA content decreased by 1.3 ± 1.3 mg.g^-1 dw (9.6 ± 9.5% of the initial content) but it was highly variable among individuals. Handling between fishing and storage should be as short and as cool as possible to preserve EPA + DHA and food safety. Regarding cooking, EPA + DHA and mono-unsaturated fatty acids increased in grilled fillets.

Amino-nanopolystyrene exposures of oyster (Crassostrea gigas) embryos induced no apparent intergenerational effects

Early life stages (ELS) of numerous marine invertebrates mustcope with man-made contaminants, including plastic debris, during their pelagic phase. Among the diversity of plastic particles, nano-sized debris, known as nanoplastics, can induce effects with severe outcomes in ELS of various biological models, including the Pacific oyster Crassostrea gigas. Here, we investigated the effects of a sub-lethal dose (0.1 µg mL^-1) of 50 nm polystyrene nanobeads (nano-PS) with amine functions on oyster embryos (24 h exposure) and we assessed consequences on larval and adult performances over two generations of oysters. Only a few effects were observed. Lipid analyses revealed that first-generation (G1) embryos exposed to nano-PS displayed a relative increase in cardiolipin content (+9.7%), suggesting a potential modification of mitochondrial functioning. G1-larvae issued from exposed embryos showed decreases in larval growth (-9%) and lipid storage (-20%). No effect was observed at the G1 adult stage in terms of growth, ecophysiological parameters (clearance and respiration rates, absorption efficiency), or reproductive outputs (gonadic development, gamete quality). Second generation (G2) larvae issued from control G1 displayed a significant growth reduction after G2 embryonic exposure to nano-PS (-24%) compared to control (as observed at the first generation), while no intergenerational effect was detected on G2 larvae issued from G1 exposed embryos. Overall, the present experimental study suggests a low incidence of a short embryonic exposure to nano-PS on oyster phenotypes along the entire life cycle until the next larval generation.

Benefit-risk associated with the consumption of fish bycatch from tropical tuna fisheries

Mercury, omega-3 (docosahexaenoic acid, DHA and eicosapentaenoic acid, EPA) and macronutrients (fat and proteins) were quantified on a wet weight (ww) basis in 20 species of fish taken as bycatch in tropical tuna fisheries. Based on a hazard quotient taking into account mercury and omega-3 contents, a benefit-risk assessment for the consumption of these pelagic species was conducted for three people categories: young children, children and adults. All fish bycatch were found to be an excellent source of proteins (min‒max = 14.4-25.2 g/100 g fillet), had low omega-6/omega-3 ratios (<1, except for silky shark), and had mercury content below the safety limits defined by sanitary agencies. Silky shark and Istiophoridae had the highest mercury contents (min‒max = 0.029-0.317 ppm ww). Omega-3 contents were the lowest in silky shark (0.2 ± 0.2 mg/100 g fillet) and the highest in striped marlin (3.6 ± 3.2 g/100 g fillet). Billfishes (Istiophoridae, including striped marlin), minor tunas (Scombridae), and Carangidae had the highest omega-3 contents (min‒max = 0.68-7.28 g/100 g fillet). The highest hazard quotient values obtained for silky shark and great barracuda reflected a lower nutritional benefit (i.e., low omega-3 source) than risk (i.e., mercury exposure), making them not advisable for consumption. Eight species had low hazard quotients, and among them cottonmouth jack and flat needlefish were found of high health interest (high protein, moderate fat contents, and low omega-6/omega-3 ratio). A daily serving portion of 85-200 g (according to people category) can be recommended for these species. Batfish, and to a lower extent pompano dolphinfish and brassy chub, can also be consumed safely and would provide greater health benefits than risks. These results advocate for a better access of these species to local populations.

Nanopolystyrene beads affect motility and reproductive success of oyster spermatozoa (Crassostrea gigas)

Oysters are keystone species that use external fertilization as a sexual mode. The gametes are planktonic and face a wide range of stressors, including plastic litter. Nanoplastics are of increasing concern because their size allows pronounced interactions with biological membranes, making them a potential hazard to marine life. In the present study, oyster spermatozoa were exposed for 1 h to various doses (from 0.1 to 25 µg mL^-1) of 50-nm polystyrene beads with amine (50-NH₂ beads) or carboxyl (50-COOH beads) functions. Microscopy revealed adhesion of particles to the spermatozoa membranes, but no translocation of either particle type into cells. Nevertheless, the 50-NH₂ beads at 10 µg mL^-1 induced a high spermiotoxicity, characterized by a decrease in the percentage of motile spermatozoa (-79%) and in the velocity (-62%) compared to control spermatozoa, with an overall drop in embryogenesis success (-59%). This major reproduction failure could be linked to a homeostasis disruption in exposed spermatozoa. The 50-COOH beads hampered spermatozoa motility only when administered at 25 µg mL^-1 and caused a decrease in the percentage of motile spermatozoa (-66%) and in the velocity (-38%), but did not affect embryogenesis success. Microscopy analyses indicated these effects were probably due to physical blockages by microscale aggregates formed by the 50-COOH beads in seawater. This toxicological study emphasizes that oyster spermatozoa are a useful and sensitive model for (i) deciphering the fine interactions underpinning nanoplastic toxicity and (ii) evaluating adverse effects of plastic nanoparticles on marine biota while waiting for their concentration to be known in the environment.

Nanoplastics exposure modulate lipid and pigment compositions in diatoms

The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS-NH₂) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 μg mL^-1) and a high (5 μg mL^-1) concentrations for 96 h. Results evidenced an impact on pigment composition associated to the light-harvesting function and photoprotection mainly at exponential phase. NP also impacted lipid composition of diatoms with a re-adjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol's at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly, exponential cultures exposed to high NP concentration showed an impairment of long chain fatty acids synthesis. Changes in pigment and lipid content of diatom' cells revealed that algae physiology is determinant in the way cells adjust their thylakoid membrane composition to cope with NP contamination stress. Compositions of reserve and membrane lipids are proposed as sensitive markers to assess the impact of NP exposure, including at potential predicted environmental doses, on marine organisms.

Trophic ecology of suspension-feeding bivalves inhabiting a north-eastern Pacific coastal lagoon: Comparison of different biomarkers

Understanding the nature and origins of food sources supporting coastal lagoon-inhabiting organisms is necessary to evaluate the ecological status of such ecosystems. The trophic ecology of a bivalve species Spondylus crassisquama was studied in the Ojo de Liebre lagoon (Baja California, Mexico), combining stable isotope (SI), fatty acid (FA) and sterol analyses along a transect under oceanic influences. The second objective of the study was to investigate if sterol compositions give complementary information to those obtained from FA and SI. Temporal and spatial patterns of the three biomarkers in bivalve tissues suggest oceanic inputs at the mouth of the lagoon, while the inner station was characterized by a contribution of local sources including an important role of micro heterotrophs. This study revealed that the association of lipid biomarkers provide higher taxonomic resolution of the spatiotemporal heterogeneity in nutrient sources influencing the trophic functioning of a large coastal lagoon.

[The reproduction of the population in the seventeenth, eighteenth, and nineteenth centuries. Examples from France and Quebec]

This article examines the descendants of four cohorts of couples formed in the seventeenth and eighteenth centuries (two cohorts in two French mountain valleys and one on the Ile-d'Orléans in Quebec). The children are separated into four categories according to their fate (deceased while still unmarried, unknown fate, married but childless, "useful children"). "Useful children", a concept used in population genetics, are those who in turn bear children. In all three places, the useful children represent only from 26 to 31% of births. The study goes on to measure the contributions made by these couples to the next generation. In the mean, each couple gave birth to little over one useful child. But the contributions of couples turns out to be very unequal. Depending on the place, from 36 to 53% of couples left no useful children behind them, while a small minority of couples made an ample contribution to the next generation. The same measure is reproduced in the constitution of the next generation, thereby showing that inequality of couples in terms of reproduction is perpetuated.

[The difference in mortality between biological children and foster children: the example of Druillat (Ain) in the seventeenth century]

Druillat, a parish in Bresse, welcomed a lot of abandoned infants who had been found a foster home by Lyons Hôtel-Dieu (hospital) during the second half of the eighteenth century. After specifying the annual volume of this incoming flow, the arrival of each infant at its foster home is considered. The notion of foster home covers in diversified family situations as far as the number of native children and infants are concerned. Through the comparison of deaths recorded locally and the Hôtel-Dieu register keeping lists of the infants' placements, the mortality of foster infants can be precise and compared to that of natives. The age at which they were put out to nurses and the host family standards of living, plays a fundamental role as far as the infant mortality risks are concerned.

Stay or leave? Individual choice and family logic: the destinations of children born in the Valserine Valley (French Jura) in the eighteenth and nineteenth centuries

"To study inheritance, it is necessary in the first place to know the number of heirs in each family, how property was divided between them, and whether their inheritance was sufficient to enable them to maintain and support several children in the parish. This study examines the process by which the populations of the parishes of Valserine Valley in France reproduce themselves from one generation to the next, by means of examining the ¿effective' progeny of couples to determine how many of them produce children (heirs) who continue to live in the Valley. The ultimate goal of these researches is to establish the characteristics of those who leave the Valley, and how these differ from those who choose to stay. The article examines whether it is possible to discern a family strategy in the way these decisions are made, and whether behavior of the persons in question is determined by individual choice."

Age of mother at last birth in two historical populations

This study uses sets of historical family reconstitutions from all of Quebec and from four villages of the Haut-Jura, France--first marriages of 2226 and 994 women, respectively--to investigate the physiological and social factors affecting age of mother at last birth before and during fertility transition. Age remained high throughout the period covered in Quebec, under 'natural' conditions, but showed a steady decline in the French material which extends to late 19th century generations practising family limitation. Age at marriage had no influence in Quebec; in France, however, women with the most surviving children at age 35 continued childbearing the latest. There was no link between biological ability to achieve a live birth, or in health status or aging rhythm, and age at last birth. Behaviour of mothers and daughters showed no relation. The variability in age at last birth thus appears to be random under natural conditions; with the onset of controls, social differences seem to influence not only the end of childbearing, but all aspects of behaviour governing final family size and child survival.

An abnormal concentration of cases of Rendu-Osler disease in the Valserine valley of the French Jura: a genealogical and demographic study

An important concentration of patients with Rendu-Osler disease occurs in the Valserine valley of the French Jura. A study of marriages shows that, in spite of its somewhat remote location, the valley cannot be considered an isolate, but that, on the contrary, exogamy is widely practised. Only 17.8% of the genes of inhabitants during the present century can be traced to the original population, but persons affected with the disease belong to a subgroup of the population which has lived in the villages for more than 10 generations. All the patients in 85 sibships are related. The smallest number of originator couples who lived at the beginning of the eighteenth century amounts to 16, the unique originator may therefore have lived approximately four generations earlier. However, as other patients who lived at the periphery of the Valserine valley do not appear to be related to any patients living in the valley, and because there has been considerable immigration into the valley, a number of hypotheses to explain the distribution of the disease in the region remain possible.

Age-related clinical profile of hereditary hemorrhagic telangiectasia in an epidemiologically recruited population

We report the results of a comprehensive and systematic clinical study of 324 patients with hereditary hemorrhagic telangiectasia, selected from a total of 1,270 cases recruited by epidemiological survey. In 94% of the cases, familial occurrence suggested autosomal dominant inheritance; maximum penetrance for at least one manifestation was 97%. Epistaxis was reported by 96% of the patients and, in more than 50%, developed before age 20. Heavy and frequent bleeding occurred mainly in middle-aged patients. Telangiectasia was documented in 74% of cases, half of whom were younger than 30 years. The frequency of involvement of the hands and wrists was 41%, and for the face, 33%. Visceral involvement was present in 25% of patients, with affected lungs and CNS in the young and gastrointestinal tract and liver in older patients. Symptomatic urinary tract involvement was seen in only two/324 patients. Involvement of other internal sites was not observed.

[Orphans and adult mortality. The example of France between 1740 and 1829]

The relationship between adult mortality and the proportion of orphans in France in the eighteenth and nineteenth centuries is analyzed. Data are from a research project developed at the Institut National d'Etudes Demographiques [INED] and concern data for some 400 communes, together with life tables developed for the periods 1740-1749 and 1820-1829. "This paper is divided in two chapters. The first chapter examines the different proportions of orphans, observed in the above mentioned periods. The second one confronts these proportions with comparable values derived from mortality tables." Consideration is given to the relationship between parents' death and timing of marriage of

[Demography and genetics. The usefulness of geneologic data banks]

The authors have tried to answer an essential question: the usefulness of data bases in Genetics and Demography. Problems concerning the collect and the treatment by computer of registers of population have been presented. The usefulness of the genealogic reconstitutions for all the fields of the research, particularly for historic demography, genetic and medical research, both basic and applied, is presented.