scholarly journals Sexual maturation and embryonic development in octopus: use of energy and antioxidant defence mechanisms using Octopus mimus as a model

2018 ◽  
Author(s):  
Alberto Olivares ◽  
Gabriela Rodríguez-Fuentes ◽  
Maite Mascaró ◽  
Ariadna Sánchez ◽  
Karen Ortega ◽  
...  
Keyword(s):  
Sexual Maturation ◽  
Biochemical Composition ◽  
Digestive Enzymes ◽  
Redox System ◽  
Defence Mechanisms ◽  
Radical Oxygen Species ◽  
Antioxidant Defence ◽  
Physiological Processes ◽  
The Status ◽  
A Site

AbstractSexual maturation and reproduction influence the status of a number of physiological processes and consequently the ecology and behaviour of cephalopods. Using Octopus mimus as model species, the present study examined the changes in biochemical composition that take place during gonadal maturation of octopus females and its consequences in embryo and hatchlings characteristics, including energetic metabolites, digestive enzymes and antioxidant defence mechanisms. A total of 32 Octopus mimus adult females were sampled during ovarian maturation; biochemical composition (metabolites and digestive enzymes) of digestive gland (DG) and ovaries (only metabolites) were followed during physiological and functional maturation. Levels of protein (Prot), triacyl glycerol (TG), cholesterol (Chol), glucose (Glu) and glycogen (Gly) were evaluated. The activity of alkaline and acidic enzymes also was measured in DG. Simultaneously, groups of eggs coming from mature females were sampled along development, and metabolites (Prot, TG, Glu, Gly, TG, Chol), digestive enzymes activity (Lipases, alkaline and acidic), antioxidant defence mechanisms and radical oxygen species (ROS) were evaluated. This study shows that ovarium is a site for reserve of some nutrients for reproduction. Presumably, TG where stored at the beginning of the maturation processes followed by Chol, both at the same time were energetically supported by Glu, derived from Gly following gluconeogenic pathways. Nutrients and enzymes (metabolic, digestive and REDOX system) where maintained without significant changes and in a low activity during organogenesis. Our findings suggest that activity was not energetically costly; in contrast, during the embryo growth there was mobilization of nutrients and activation of the metabolic and digestive enzymes. Increments in consumption of yolk and glycogen, and reduction in molecules associated with oxidative stress allowed paralarvae to hatch with the antioxidant defence mechanisms ready to support ROS production.

scholarly journals Maturation trade-offs in octopus females and their progeny: energy, digestion and defence indicators

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6618 ◽  
Author(s):  
Alberto Olivares ◽  
Gabriela Rodríguez-Fuentes ◽  
Maite Mascaró ◽  
Ariadna Sanchez Arteaga ◽  
Karen Ortega ◽  
...  
Keyword(s):  
Enzyme Activities ◽  
Digestive Enzymes ◽  
Digestive Enzyme ◽  
Life Stage ◽  
Detoxification Enzymes ◽  
Physiological Processes ◽  
Functional Maturation ◽  
Trade Offs ◽  
The Status ◽  
Digestive Enzyme Activities

Sexual maturation and reproduction influence the status of a number of physiological processes and consequently the ecology and behaviour of cephalopods. Using Octopus mimus as a study model, the present work was focused in the changes in biochemical compound and activity that take place during gonadal maturation of females and its consequences in embryo and hatchlings characteristics. To do that, a total of 31 adult females of O. mimus were sampled to follow metabolites (ovaries and digestive gland) and digestive enzyme activities (alkaline and acidic proteases) during physiological and functional maturation. Levels of protein (Prot), triacylglyceride (TG), cholesterol (Chol), glucose (Glu), and glycogen (Gly) were evaluated. Groups of eggs coming from mature females were also sampled along development and after hatching (paralarvae of 1 and 3 days old) to track metabolites (Prot, TG, Glu, Gly, TG, Chol), digestive enzymes activity (Lipase, alkaline proteases, and acidic proteases), and antioxidant/detoxification defence indicators with embryos development. Based on the data obtained, we hypothesized that immature females store Chol in their ovaries, probably from the food they ingested, but switch to TG reserves at the beginning of the maturation processes. At the same time, results suggest that these processes were energetically supported by Glu, obtained probably from Gly breakdown by gluconeogenic pathways. Also, was observed that embryos metabolites and enzyme activities (digestive and antioxidant/detoxification enzymes) where maintained without significant changes and in a low activity during the whole organogenesis, meaning that organogenesis is relatively not energetically costly. In contrast, after organogenesis, a mobilization of nutrients and activation of the metabolic and digestive enzymes was observed, together with increments in consumption of yolk and Gly, and reduction in lipid peroxidation. Derived from our results, we also have the hypothesis that reactive oxygen species (ROS) were produced during the metabolic processes that occurs in ovarian maturation. Those ROS may be in part transferred to the egg provoking a ROS charge to the embryos. The elimination of ROS in embryos started when the activity of the heart and the absorption of the yolk around stages XIV and XV were evident. Altogether, these processes allowed the paralarvae to hatch with buffered levels of ROS and with the antioxidant defence mechanisms ready to support further ROS production derived from paralarvae higher life stage requirements (feeding and metabolic demands).

scholarly journals Consecutive sexual maturation observed in a rock shell population in the vicinity of the Fukushima Daiichi Nuclear Power Plant, Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshihiro Horiguchi ◽  
Kayoko Kawamura ◽  
Yasuhiko Ohta
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Sexual Maturation ◽  
Nuclear Power ◽  
Tohoku Earthquake ◽  
Site Specific ◽  
Thais Clavigera ◽  
Rock Shell ◽  
Fukushima Daiichi ◽  
A Site

AbstractIn 2012, after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) that followed the Tohoku earthquake and tsunami in March 2011, no rock shell (Thais clavigera; currently recognized as Reishia clavigera; Gastropoda, Neogastropoda, Muricidae) specimens were found near the plant from Hirono to Futaba Beach (a distance of approximately 30 km). In July 2016, however, rock shells were again found to inhabit the area. From April 2017 to May 2019, we collected rock shell specimens monthly at two sites near the FDNPP (Okuma and Tomioka) and at a reference site ~ 120 km south of the FDNPP (Hiraiso). We examined the gonads of the specimens histologically to evaluate their reproductive cycle and sexual maturation. The gonads of the rock shells collected at Okuma, ~ 1 km south of the FDNPP, exhibited consecutive sexual maturation during the 2 years from April 2017 to May 2019, whereas sexual maturation of the gonads of specimens collected at Hiraiso was observed only in summer. The consecutive sexual maturation of the gonads of the specimens collected at Okuma might not represent a temporary phenomenon but rather a site-specific phenotype, possibly caused by specific environmental factors near the FDNPP.

Antioxidant defence mechanisms: From the beginning to the end (of the beginning)

1999 ◽  
Vol 31 (4) ◽  
pp. 261-272 ◽  
Author(s):  
Barry Halliwell
Keyword(s):  
Defence Mechanisms ◽  
Antioxidant Defence

Tandem Pore Domain Potassium Channels

2019 ◽  
Author(s):  
Douglas A. Bayliss
Keyword(s):  
Single Channel ◽  
Resting Membrane Potential ◽  
K2p Channel ◽  
Physiological Processes ◽  
System A ◽  
Wide Range ◽  
K2p Channels ◽  
To Come ◽  
A Site ◽  
Pore Domain

The KCNK gene family encodes two-pore-domain potassium (K2P) channels, which generate the background (“leak”) K+ currents that establish a negative resting membrane potential in cells of the nervous system. A pseudotetrameric K+-selective pore is formed by pairing channel subunits, each with two pore-domains, in homo- or heterodimeric conformations. Unique features apparent from high-resolution K2P channel structures include a domain-swapped extracellular cap domain, a lateral hydrophobic-lined fenestration connecting the lipid bilayer to the channel vestibule, and an antiparallel proximal C-terminal region that links the paired subunits and provides a site for polymodal channel modulation. Individual channels transition between open and closed states, with the channel gate located at the selectivity filter. In general, K2P channels display relatively modest voltage- and time-dependent gating, together with distinct single-channel rectification properties, that conspire to yield characteristic weakly rectifying macroscopic currents over a broad range of membrane potentials (i.e., background K+ currents). Of particular note, K2P channel activity can be regulated by a wide range of physicochemical factors, neuromodulators, and clinically useful drugs; a distinct repertoire of activators and inhibitors for different K2P channel subtypes endows each with unique modulatory potential. Thus, by mediating background currents and serving as targets for multiple modulators, K2P channels are able to dynamically regulate key determinants of cell-intrinsic electroresponsive properties. The roles of specific K2P channels in various physiological processes and pathological conditions are now beginning to come into focus, and this may portend utility for these channels as potential therapeutic targets.

scholarly journals Effect of a Protein-Xanthophyll Concentrate from Alfalfa and of Genotype and Sex of Lambs on their Blood Redox Profile

2012 ◽  
Vol 56 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Katarzyna Ognik ◽  
Krzysztof Patkowski ◽  
Eugeniusz R. Grela
Keyword(s):  
Superoxide Dismutase ◽  
Vitamin C ◽  
Redox Potential ◽  
Antioxidant Potential ◽  
Defence Mechanisms ◽  
Antioxidant Defence ◽  
Total Antioxidant ◽  
Total Antioxidant Potential

Abstract The experiment was conducted on lambs of the Polish Lowland sheep (PLS) and a synthetic BCP line. The redox potential was assessed in blood of lambs with different genotype and sex, which were fed feed mixtures with various contents of a proteinxanthophyll (PX) concentrate from alfalfa (1.5% and 3%). The 1.5% addition of PX concentrate to feed stimulated the response of the antioxidant defence mechanisms of the lambs to a greater extent than the 3% addition. The study showed that sex of the lambs had no significant effect on changes in the redox parameters of blood. The PLS genotype of lambs determined higher values of superoxide dismutase (SOD), total antioxidant potential of plasma (FRAP), malondialdehyde, and vitamin C than the BCP genotype. Along with the growth of the lambs, a descending tendency was observed in SOD and catalase levels, and an ascending tendency in FRAP value.

Suffering and Sacrifice

2019 ◽  
Vol 3 (1) ◽  
pp. 56-76
Author(s):  
Sarah Wolf
Keyword(s):  
Late Antique ◽  
Babylonian Talmud ◽  
Early Christian ◽  
Close Analysis ◽  
Physical Suffering ◽  
The Status ◽  
Spiritual Self ◽  
And Function ◽  
A Site ◽  
The Relationship

This article offers the argument that suffering (yisurin) in the Babylonian Talmud functions as a locus for the relationship between God and rabbinic Jews. Scholars of rabbinic martyrdom and asceticism have tended to claim that the Talmud's positive portrayal of suffering is a theodical apology for unexplained evil in the world. However, the article argues that the Talmud—in contrast to earlier rabbinic texts—presents suffering as spiritually relevant not primarily to justify preexisting suffering, but rather to develop a site at which to interpret information about an individual's spiritual status. The article draws on theories of sacrifice's structure and function, in conjunction with close analysis of rabbinic texts that relate suffering to sacrifice. The pericope at the core of the article's argument demonstrates a strikingly technical approach to the human experience of suffering, describing four examples of yisurin in which no real physical suffering occurs; in each instance the “victim” experiences extremely mild discomfort at most, and at the least barely registers an experience of inconvenience. Nonetheless, these experiences all qualify as “suffering,” and are thus still understood to bear indisputable soteriological import. Physical suffering in the Talmud is thus open for interpretation, yielding information about the status of the sufferer's spiritual self. Human suffering is viewed as religiously desirable in both late rabbinic and early Christian literatures. By developing an understanding of its hermeneutical function for the rabbis, this article helps to elucidate the value of suffering for rabbinic literature as a subset of late antique religious discourse.

Effect of Nicotine on Antioxidant Defence Mechanisms in Rats Fed a High-Fat Diet

Pharmacology ◽  
1996 ◽  
Vol 52 (3) ◽  
pp. 153-158 ◽  
Author(s):  
L. Ashakumary ◽  
P.L. Vijayammal
Keyword(s):  
High Fat Diet ◽  
High Fat ◽  
Defence Mechanisms ◽  
Antioxidant Defence

Adaptation of the Blood Antioxidant Defence Mechanisms of Sheep with a Genetic Lesion Resulting in Low Red Cell Glutathione Concentrations

1993 ◽  
Vol 18 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Donald B. McPhail ◽  
Philip C. Morrice ◽  
Garry G. Duthie ◽  
J. V. Bannister
Keyword(s):  
Red Cell ◽  
Defence Mechanisms ◽  
Antioxidant Defence ◽  
Genetic Lesion

The value of and values in the work of teachers in Estonia

2016 ◽  
Vol 31 (2) ◽  
pp. 248-264 ◽  
Author(s):  
Eeva Kesküla ◽  
Krista Loogma
Keyword(s):  
Life History ◽  
Social Groups ◽  
Rapid Change ◽  
Value System ◽  
Material Recognition ◽  
Anthropological Theory ◽  
Societal Value ◽  
The Status ◽  
Theory Of Value ◽  
A Site

This article considers how the status of teachers relates to a changing value system, and how the perceived worth of a profession depends on the values its practitioners carry. The article analyses the work of teachers as both productive and reproductive, needing both material and non-material recognition. It argues that in times of radical social change, social groups struggle to determine what value is. The rapid introduction of a neoliberal market economy in Estonia has created a situation where teachers’ labour becomes a site of contestation determining what values prevail in society. Based on 24 semi-structured life history interviews, this article combines theories of the value of labour, of professionalism and the anthropological theory of value to argue for the key role that teachers play during rapid change to a societal value regime.

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