scholarly journals Toward a More Comprehensive View of α-Amylase across Decapods Crustaceans

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 947
Author(s):  
Leandro Rodríguez-Viera ◽  
Daniel Alpízar-Pedraza ◽  
Juan Miguel Mancera ◽  
Erick Perera
Keyword(s):  
Amylase Activity ◽  
Feeding Habits ◽  
Carbohydrate Content ◽  
Molt Cycle ◽  
Comprehensive View ◽  
Low Carbohydrate ◽  
Enzyme Sequence ◽  
Carnivorous Species ◽  
Selection Force ◽  
Diet Shifts

Decapod crustaceans are a very diverse group and have evolved to suit a wide variety of diets. Alpha-amylases enzymes, responsible for starch and glycogen digestion, have been more thoroughly studied in herbivore and omnivore than in carnivorous species. We used information on the α-amylase of a carnivorous lobster as a connecting thread to provide a more comprehensive view of α-amylases across decapods crustaceans. Omnivorous crustaceans such as shrimps, crabs, and crayfish present relatively high amylase activity with respect to carnivorous crustaceans. Yet, contradictory results have been obtained and relatively high activity in some carnivores has been suggested to be a remnant trait from ancestor species. Here, we provided information sustaining that high enzyme sequence and overall architecture conservation do not allow high changes in activity, and that differences among species may be more related to number of genes and isoforms, as well as transcriptional and secretion regulation. However, recent evolutionary analyses revealed that positive selection might have also occurred among distant lineages with feeding habits as a selection force. Some biochemical features of decapod α-amylases can be related with habitat or gut conditions, while less clear patterns are observed for other enzyme properties. Likewise, while molt cycle variations in α-amylase activity are rather similar among species, clear relationships between activity and diet shifts through development cannot be always observed. Regarding the adaptation of α-amylase to diet, juveniles seem to exhibit more flexibility than larvae, and it has been described variation in α-amylase activity or number of isoforms due to the source of carbohydrate and its level in diets, especially in omnivore species. In the carnivorous lobster, however, no influence of the type of carbohydrate could be observed. Moreover, lobsters were not able to fine-regulate α-amylase gene expression in spite of large changes in carbohydrate content of diet, while retaining some capacity to adapt α-amylase activity to very low carbohydrate content in the diets. In this review, we raised arguments for the need of more studies on the α-amylases of less studied decapods groups, including carnivorous species which rely more on dietary protein and lipids, to broaden our view of α-amylase in decapods crustaceans.

scholarly journals Toward a More Comprehensive View of α-Amylase across Decapods Crustaceans: New Insights from Carnivorous

2021 ◽  
Author(s):  
Leandro Rodriguez-Viera ◽  
Daniel Alpízar-Pedraza ◽  
Juan Miguel Mancera ◽  
Erick Perera
Keyword(s):  
Amylase Activity ◽  
Feeding Habits ◽  
Carbohydrate Content ◽  
Alpha Amylase ◽  
Molt Cycle ◽  
Comprehensive View ◽  
Enzyme Sequence ◽  
Carnivorous Species ◽  
Alpha Amylase Gene ◽  
Alpha Amylases

Decapod crustaceans are a very diverse group and have evolved to suit a wide variety of diets. Alpha-amylases enzymes, responsible for starch and glycogen digestion, have been more thoroughly studies in herbivore and omnivore than in carnivorous species. We used information on the α-amylase of a carnivorous lobster as a connecting thread to provide a more comprehensive view of α-amylases across decapods crustaceans. Omnivorous crustaceans such as shrimps, crabs and crayfish present relatively high amylase activity respect to carnivorous. Yet, contradictory results have been obtained and relatively high activity in some carnivores has been suggested to be a remnant trait from ancestor species. Here we provided information sustaining that high enzyme sequence and overall architecture conservation do not allow high changes in activity, and that differences among species may be more related to number of genes and isoforms, as well as transcriptional and secretion regulation. However, recent evolutionary analyses revealed that positive selection might have also occurred among distant lineages with feeding habits as a selection force. Some biochemical features of decapod α-amylases can be related with habitat or gut conditions, while less clear patterns are observed for other enzyme properties. Likewise, while molt cycle variations in α-amylase activity are rather similar among species, clear relationships between activity and diet shifts through development cannot be always observed. Regarding the adaptation of α-amylase to diet, juveniles seem to exhibit more flexibility than larvae, and it has been described variation in α-amylase activity or number of isoforms due to the source of carbohydrate and its level in diets, especially in omnivore species. In the carnivorous lobster, however, no influence of the type of carbohydrate could be observed. Also, lobsters were not able to fine-regulate α-amylase gene expression in spite of large changes in carbohydrate content of diet, while retaining some capacity to adapt α-amylase activity to very low carbohydrate content in the diets. In this review, we raised arguments for the need of more studies on the α-amylases of less studied decapods groups, including carnivorous species which rely more on dietary protein and lipids, to broad our view of α-amylase in decapods crustaceans.

Detailed comparative morphology of the peri-oral structures of the Mysidacea and Euphausiacea (Crustacea): an indication for the food preference

2001 ◽  
Vol 81 (2) ◽  
pp. 235-241 ◽  
Author(s):  
L. De Jong-Moreau ◽  
B. Casanova ◽  
J.-P. Casanova
Keyword(s):  
Food Preference ◽  
Feeding Habits ◽  
Comparative Morphology ◽  
Gut Content ◽  
Scanning Microscope ◽  
Content Analyses ◽  
Carnivorous Species ◽  
Meganyctiphanes Norvegica ◽  
Molar Process

Scanning microscope investigations were carried out on mandibles, labrum and paragnaths of several species of Mysidacea and Euphausiacea. Gut content analyses were in agreement with morphological observations. It appears that the morphology of the peri-oral structures and especially of the mandibles reflect the feeding habits, and that the well known relationships between the size of the molar process and the incisor one, i.e. a large molar process is associated with herbivorous feeding, is not always verified. Bacescomysis abyssalis and Bentheuphausia amblyops are believed to be mostly saprophagous, Boreomysis inermis and Meganyctiphanes norvegica are mostly phytophagous, Hemimysis speluncola is omnivorous, while Siriella armata and Thysanopoda orientalis are carnivorous species.

scholarly journals Ontogeny of Expression and Activity of Digestive Enzymes and Establishment of gh/igf1 Axis in the Omnivorous Fish Chelon labrosus

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 874 ◽  
Author(s):  
Neda Gilannejad ◽  
Verónica de las Heras ◽  
Juan Antonio Martos-Sitcha ◽  
Francisco J. Moyano ◽  
Manuel Yúfera ◽  
...  
Keyword(s):  
Digestive Enzymes ◽  
Specific Activity ◽  
Amylase Activity ◽  
Expression Patterns ◽  
Feeding Preferences ◽  
Protein Requirements ◽  
Expression Of Genes ◽  
Carnivorous Species ◽  
Juvenile Stages ◽  
Chelon Labrosus

Thick-lipped grey mullet (Chelon labrosus) is a candidate for sustainable aquaculture due to its omnivorous/detritivorous feeding habit. This work aimed to evaluate its digestive and growth potentials from larval to early juvenile stages. To attain these objectives the activity of key digestive enzymes was measured from three until 90 days post hatch (dph). Expression of genes involved in digestion of proteins (try2, ctr, pga2, and atp4a), carbohydrates (amy2a), and lipids (cel and pla2g1b), together with two somatotropic factors (gh and igf1) were also quantified. No chymotrypsin or pepsin activities were detected. While specific activity of trypsin and lipase were high during the first 30 dph and declined afterward, amylase activity was low until 57 dph and increased significantly beyond that point. Expression of try2, ctr, amy2a, and cel increased continuously along development, and showed a peak at the end of metamorphosis. Expression of pla2g1b, pga2 and atp4a increased until the middle of metamorphosis and decreased afterwars. Most of these trends contrast the usual patterns in carnivorous species and highlight the transition from larvae, with high protein requirements, to post-larvae/juvenile stages, with omnivorous/detritivorous feeding preferences. Somatotropic genes, gh and igf1, showed approximately inverse expression patterns, suggesting the establishment of the Gh/Igf1 axis from 50 dph.

scholarly journals Overweight and diabetes prevention: is a low-carbohydrate–high-fat diet recommendable?

2018 ◽  
Vol 57 (4) ◽  
pp. 1301-1312 ◽  
Author(s):  
Fred Brouns
Keyword(s):  
Type 2 Diabetes ◽  
Weight Loss ◽  
Carbohydrate Content ◽  
Food Sources ◽  
Long Term Effects ◽  
High Fat ◽  
Functional Changes ◽  
Low Carbohydrate

Abstract In the past, different types of diet with a generally low-carbohydrate content (< 50–< 20 g/day) have been promoted, for weight loss and diabetes, and the effectiveness of a very low dietary carbohydrate content has always been a matter of debate. A significant reduction in the amount of carbohydrates in the diet is usually accompanied by an increase in the amount of fat and to a lesser extent, also protein. Accordingly, using the term “low carb–high fat” (LCHF) diet is most appropriate. Low/very low intakes of carbohydrate food sources may impact on overall diet quality and long-term effects of such drastic diet changes remain at present unknown. This narrative review highlights recent metabolic and clinical outcomes of studies as well as practical feasibility of low LCHF diets. A few relevant observations are as follows: (1) any diet type resulting in reduced energy intake will result in weight loss and related favorable metabolic and functional changes; (2) short-term LCHF studies show both favorable and less desirable effects; (3) sustained adherence to a ketogenic LCHF diet appears to be difficult. A non-ketogenic diet supplying 100–150 g carbohydrate/day, under good control, may be more practical. (4) There is lack of data supporting long-term efficacy, safety and health benefits of LCHF diets. Any recommendation should be judged in this light. (5) Lifestyle intervention in people at high risk of developing type 2 diabetes, while maintaining a relative carbohydrate-rich diet, results in long-term prevention of progression to type 2 diabetes and is generally seen as safe.

Feeding habits of the velvet belly lanternshark Etmopterus spinax (Chondrichthyes: Etmopteridae) off the Algarve, southern Portugal

2006 ◽  
Vol 86 (4) ◽  
pp. 835-841 ◽  
Author(s):  
João Neiva ◽  
Rui Coelho ◽  
Karim Erzini
Keyword(s):  
Deep Water ◽  
Foraging Behaviour ◽  
Prey Size ◽  
Feeding Habits ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Prey Composition ◽  
Southern Portugal ◽  
Meganyctiphanes Norvegica ◽  
Diet Shifts

Etmopterus spinax is one of the most abundant predators of the upper continental slope off the Algarve (southern Portugal), where it is captured in large quantities in deep-water fisheries. The feeding habits of E. spinax off the Algarve were investigated through the analysis of stomach contents of 376 individuals. Prey composition was described and maturity, sex and size related variations in the diet analysed. The overall diet of E. spinax suggested a fairly generalized benthopelagic foraging behaviour primarily tuned to pelagic macroplankton/microneckton, teleost fish and cephalopods. Sex and maturity related differences in the diet were not significant. Two main ontogenic diet shifts were observed at about 17 and 28 cm total length. Small and medium sized immature sharks had a diet dominated by eurybathic crustaceans, chiefly Meganyctiphanes norvegica and Pasiphaea sivado. Larger individuals consumed more teleosts and cephalopods, in part associated with scavenging as a new feeding strategy. With increasing shark size the diet diversified both in terms of resources exploited and prey size.

scholarly journals Nutritional regulation of glucokinase: a cross-species story

2014 ◽  
Vol 27 (1) ◽  
pp. 21-47 ◽  
Author(s):  
Stéphane Panserat ◽  
Nicole Rideau ◽  
Sergio Polakof
Keyword(s):  
Rainbow Trout ◽  
Animal Species ◽  
Feeding Habits ◽  
Present Review ◽  
Nutritional Regulation ◽  
Dietary Carbohydrates ◽  
Biochemical Characteristics ◽  
Nutritional Importance ◽  
Carnivorous Species ◽  
Different Levels

The glucokinase (GK) enzyme (EC 2.7.1.1.) is essential for the use of dietary glucose because it is the first enzyme to phosphorylate glucose in excess in different key tissues such as the pancreas and liver. The objective of the present review is not to fully describe the biochemical characteristics and the genetics of this enzyme but to detail its nutritional regulation in different vertebrates from fish to human. Indeed, the present review will describe the existence of the GK enzyme in different animal species that have naturally different levels of carbohydrate in their diets. Thus, some studies have been performed to analyse the nutritional regulation of the GK enzyme in humans and rodents (having high levels of dietary carbohydrates in their diets), in the chicken (moderate level of carbohydrates in its diet) and rainbow trout (no carbohydrate intake in its diet). All these data illustrate the nutritional importance of the GK enzyme irrespective of feeding habits, even in animals known to poorly use dietary carbohydrates (carnivorous species).

scholarly journals The influence of nitrogen fertilizations and light intersity on mother plants productivity and the rooting of cuttings of Chrysanthemum (cultivar - Horim Golden)

2013 ◽  
Vol 45 (1-2) ◽  
pp. 61-74
Author(s):  
Lidia Kozłowska
Keyword(s):  
Light Intensity ◽  
Nitrogen Fertilization ◽  
Carbohydrate Content ◽  
Clear Correlation ◽  
Fluorescent Lamps ◽  
Low Carbohydrate ◽  
Mother Plants ◽  
Rooting Of Cuttings ◽  
Nitrogen Ratio ◽  
High Intensity Light

Mother plants of <i>Chrysanthemum</i> cv. "Horim Golden" have been cultivated at three levels of nitrogen fertilization, dosage for a 3 l pot was 100,500,1000 mg N. The plants were growing with fluorescent lamps on (5000 lx or 10000 lx). The rooting of the cuttings obtained under such conditions took place with 5000 lx. The effect of nitrogen on the productivity of mother plants depended on the light intensity. Higher nitrogen doses affected favourably the number of cuttings, the growth and number of roots per cuttings - only when higher light intensity was applied for mother plants. Light of various intensity used in the cultivation of chrysanthemum mother plants had a significantly higher effect on the dynamics of rooting that did nitrogen fertilization. High intensity light, irrespective of the nitrogen dose used, also increased the weight and number of roots per cutting. Moreover, a clear correlation has been found between the carbohydrate content in cuttings and the dynamics of rooting and the number and weight of roots formed. The process of root formation took place later and was slower in cuttings in which a higher carbohydrate content was found; however, the number and weight of roots formed by these cuttings were considerably higher. In cuttings characterised by a low carbohydrate; total nitrogen ratio a decrease in the number and weight of roots has been found.

scholarly journals Ketogenic Diet for Cancer: Critical Assessment and Research Recommendations

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3562
Author(s):  
Jordin Lane ◽  
Nashira I. Brown ◽  
Shanquela Williams ◽  
Eric P. Plaisance ◽  
Kevin R. Fontaine
Keyword(s):  
Clinical Trials ◽  
Ketogenic Diet ◽  
The United States ◽  
Carbohydrate Content ◽  
Cancer Development ◽  
Antitumor Effects ◽  
Low Protein ◽  
Low Carbohydrate ◽  
Diet And Lifestyle ◽  
Research Recommendations

Despite remarkable improvements in screening, diagnosis, and targeted therapies, cancer remains the second leading cause of death in the United States. It is increasingly clear that diet and lifestyle practices play a substantial role in cancer development and progression. As such, various dietary compositions have been proposed for reducing cancer risk and as potential adjuvant therapies. In this article, we critically assess the preclinical and human trials on the effects of the ketogenic diet (KD, i.e., high-fat, moderate-to-low protein, and very-low carbohydrate content) for cancer-related outcomes. The mechanisms underlying the hypothesized effects of KD, most notably the Warburg Effect, suggest that restricting carbohydrate content may impede cancer development and progression via several pathways (e.g., tumor metabolism, gene expression). Overall, although preclinical studies suggest that KD has antitumor effects, prolongs survival, and prevents cancer development, human clinical trials are equivocal. Because of the lack of high-quality clinical trials, the effects of KD on cancer and as an adjunctive therapy are essentially unknown. We propose a set of research recommendations for clinical studies examining the effects of KD on cancer development and progression.

scholarly journals Dietary Carbohydrate Deprivation Increases 24-Hour Nitrogen Excretion without Affecting Postabsorptive Hepatic or Whole Body Protein Metabolism in Healthy Men

2003 ◽  
Vol 88 (8) ◽  
pp. 3801-3805 ◽  
Author(s):  
P. H. Bisschop ◽  
M. G. M. de Sain-van der Velden ◽  
F. Stellaard ◽  
F. Kuipers ◽  
A. J. Meijer ◽  
...  
Keyword(s):  
Total Energy ◽  
Protein Metabolism ◽  
Carbohydrate Content ◽  
Nitrogen Excretion ◽  
Whole Body ◽  
Dietary Carbohydrate ◽  
High Fat ◽  
Body Protein ◽  
Healthy Men ◽  
Low Carbohydrate

Because insulin is an important regulator of protein metabolism, we hypothesized that physiological modulation of insulin secretion, by means of extreme variations in dietary carbohydrate content, affects postabsorptive protein metabolism. Therefore, we studied the effects of three isocaloric diets with identical protein content and low-carbohydrate/high-fat (2% and 83% of total energy, respectively), intermediate-carbohydrate/intermediate-fat (44% and 41% of total energy, respectively), and high-carbohydrate/low-fat (85% and 0% of total energy, respectively) content in six healthy men. Whole body protein metabolism was assessed by 24-h urinary nitrogen excretion, postabsorptive leucine kinetics, and fibrinogen and albumin synthesis by infusion of [1-13C]leucine and [1-13C]valine. The low-carbohydrate/high-fat diet resulted in lower absorptive and postabsorptive plasma insulin concentrations, and higher rates of nitrogen excretion compared with the other two diets: 15.3 ± 0.9 vs. 12.1 ± 1.1 (P = 0.03) and 10.8 ± 0.5 g/24 h (P = 0.005), respectively. Postabsorptive rates of appearance of leucine and of leucine oxidation were not different among the three diets. In addition, dietary carbohydrate content did not affect the synthesis rates of fibrinogen and albumin. In conclusion, eucaloric carbohydrate deprivation increases 24-h nitrogen loss but does not affect postabsorptive protein metabolism at the hepatic and whole body level. By deduction, dietary carbohydrate is required for an optimal regulation of absorptive, rather than postabsorptive, protein metabolism.

Sign in / Sign up

Export Citation Format

Share Document