scholarly journals Can mammalian mothers influence the sex of their offspring peri-conceptually?

Reproduction ◽  
2010 ◽  
Vol 140 (3) ◽  
pp. 425-433 ◽  
Author(s):  
Valerie J Grant ◽  
Lawrence W Chamley
Keyword(s):  
Evolutionary Biology ◽  
Sex Allocation ◽  
Molecular Mechanisms ◽  
Good Condition ◽  
The Other ◽  
Proximate Mechanisms ◽  
High Fat Diets ◽  
Fat Diets ◽  
To Receive ◽  
Maternal Glucose

Although controversial, growing evidence from evolutionary biology suggests that the mammalian mother may have a role in influencing the sex of her offspring. However, there is competing information on the molecular mechanisms by which such influence could be manifested. The new initiatives are based on hypotheses from evolutionary biology: the ‘good condition’ hypothesis, which suggests that post conception, higher levels of maternal glucose may differentially promote the development of male embryos; and the ‘maternal dominance’ hypothesis, which proposes that before conception, higher follicular testosterone may influence the development of the ovum so that it emerges already adapted to receive an X- or a Y-chromosome-bearing spermatozoon. Now, it seems these hypothesised mechanisms could be operating in synchrony, each complementing and reinforcing the other. On the other hand, there are continuing problems in identifying a precise sequence of mechanisms as evidenced from research in sperm-sorting. Research on high-fat diets and the sex ratio in polytocous species may indicate important differences in proximate mechanisms for sex allocation between polytocous and monotocous mammals.

scholarly journals Serum lipids, hepatic glycerolipid metabolism and peroxisomal fatty acid oxidation in rats fed ω-3 and ω-6 fatty acids

1992 ◽  
Vol 283 (2) ◽  
pp. 333-339 ◽  
Author(s):  
A C Rustan ◽  
E N Christiansen ◽  
C A Drevon
Keyword(s):  
Fatty Acids ◽  
Fish Oil ◽  
Linseed Oil ◽  
The Other ◽  
Acid Oxidation ◽  
High Fat ◽  
High Fat Diets ◽  
Peroxisomal Fatty Acid Oxidation ◽  
Fat Diets ◽  
Peroxisomal Fatty Acid

Rats were fed, for 3 weeks, high-fat (20% w/w) diets containing sunflower-seed oil, linseed oil or fish oil. Chow-fed rats were used as a low-fat reference. The high-fat diets markedly reduced non-fasting-rat serum triacylglycerol as compared with the low-fat reference, and the highest reduction (85%) was observed with the fish-oil group, which was significantly lower than that of the other high-fat diets. The serum concentration of phospholipids was significantly reduced (30%) only in the fish-oil-fed animals, whereas serum non-esterified fatty acids were reduced 40-50% by both the fish-oil- and linseed-oil-fed groups. The liver content of triacylglycerol showed a 1.7-fold increase with the fish-oil diet and 2-2.5-fold with the other dietary groups when compared with rats fed a low-fat diet, whereas the hepatic content of phospholipids was unchanged. Peroxisomal fatty acid oxidation (acyl-CoA oxidase) was 2-fold increased for the rats fed fish oil; however this was not significantly higher when comparison was made with rats fed the linseed-oil diet. There was no difference in phosphatidate hydrolysis (microsomal and cytosolic fractions) among animals fed the various diets. Acyl-CoA:diacylglycerol acyltransferase activity was increased by all high-fat diets, but the fish-oil-diet-fed group showed a significantly lower enzyme activity than did rats fed the other high-fat diets. A linear correlation between acyl-CoA:diacylglycerol acyltransferase activity and liver triacylglycerol was observed, and the microsomal enzyme activity was decreased 40-50% by incubation in the presence of eicosapentaenoyl-CoA. CoA derivatives of arachidonic, linolenic and linoleic acid had no inhibitory effect when compared with the control. These results indicate that dietary fish oil may have greater triacylglycerol-lowering effect than other polyunsaturated diets, owing to decreased triacylglycerol synthesis caused by inhibition of acyl-CoA:diacylglycerol acyltransferase. In addition, increased peroxisomal fatty acid oxidation and decreased availability of non-esterified fatty acids could also contribute by decreasing the amounts of fatty acids as substrates for triacylglycerol synthesis and secretion.

Statistic Comparison between High-Fat Gavage and Feeding to Establish Hyperlipemia Rat Model

2013 ◽  
Vol 641-642 ◽  
pp. 812-815
Author(s):  
Hong Yan Ma ◽  
Fang Wang ◽  
Jing Sheng Du
Keyword(s):  
Body Weight ◽  
Rat Model ◽  
Physiological Parameters ◽  
The Other ◽  
Control Group ◽  
Statistic Analysis ◽  
High Fat ◽  
Significant Difference ◽  
High Fat Diets ◽  
Fat Diets

The study established hyperlipemia rat model by high-fat diets feeding and high-fat solution gavage. Body weight and related bio-physiological parameters in plasma after 30 days of treatment were tested and then statistic analysis was performed. Body weight and bio-physiological parameters had significant difference in both high-fat diets feeding and high-fat solution gavage groups when they were compared with control group. Results of statistic analysis about two groups showed that the way of high-fat solution gavaging could reduce the influence on individual difference, meanwhile it could improve the uniformity and scientificity of the data compared with the other one.

Effect of dietary fat on the retention of calcium and phosphorus in buffaloes (Bos bubalis)

1983 ◽  
Vol 100 (2) ◽  
pp. 359-362
Author(s):  
K. Nath ◽  
O. N. Agarwala
Keyword(s):  
Adverse Effect ◽  
Dietary Fat ◽  
The Other ◽  
High Fat ◽  
Groundnut Oil ◽  
P Nutrition ◽  
High Fat Diets ◽  
Calcium And Phosphorus ◽  
Fat Diets ◽  
Supplemental Fat

SUMMARYFive feeding and metabolism trials were conducted on buffaloes fed different amounts of groundnut oil as a source of supplemental fat. Ca and P retentions were determined. The first two trials were conducted on 12 and 16 milch buffaloes and the other three trials on 15, 15 and 4 buffalo bulls. The dietary fat ranged from 1·32 to 6·00% of the ration in milch buffaloes and 0·51 to 6·33% in buffalo bulls. The retentions of Ca and P did not differ significantly with the percentage of fat in the ration. This showed that the phenomenon of formation of Ca soaps with fatty acids in non-ruminants with consequent wastage of Ca does not seem to be applicable to ruminants which have a much lower pH in the duodenum and upper jejunum. It is concluded that under practical conditions of feeding, within the usual range of dietary fat in ruminants, there is no likelihood of an adverse effect on Ca and P nutrition such as is encountered in non-ruminants on high-fat diets.

scholarly journals The Trivers–Willard hypothesis: sex ratio or investment?

2016 ◽  
Vol 283 (1830) ◽  
pp. 20160126 ◽  
Author(s):  
Carl Veller ◽  
David Haig ◽  
Martin A. Nowak
Keyword(s):  
Simple Model ◽  
Sex Ratio ◽  
Sex Allocation ◽  
Good Condition ◽  
The Other ◽  
Reproductive Value ◽  
Small Subset ◽  
Female Fitness ◽  
Male And Female ◽  
Fitness Functions

The Trivers–Willard hypothesis has commonly been considered to predict two things. First, that a mother in good condition should bias the sex ratio of her offspring towards males (if males exhibit greater variation in reproductive value). Second, that a mother in good condition should invest more per son than per daughter. These two predictions differ empirically, mechanistically and, as we demonstrate here, theoretically too. We construct a simple model of sex allocation that allows simultaneous analysis of both versions of the Trivers–Willard hypothesis. We show that the sex ratio version holds under very general conditions, being valid for a large class of male and female fitness functions. The investment version, on the other hand, is shown to hold only for a small subset of male and female fitness functions. Our results help to make sense of the observation that the sex ratio version is empirically more successful than the investment version.

Non-Fasting Factor VII Coagulant Activity (FVII:C) Increased by High-Fat Diet

1994 ◽  
Vol 71 (06) ◽  
pp. 755-758 ◽  
Author(s):  
E M Bladbjerg ◽  
P Marckmann ◽  
B Sandström ◽  
J Jespersen
Keyword(s):  
High Fat Diet ◽  
Fat Content ◽  
Factor Vii ◽  
Amidolytic Activity ◽  
High Fat ◽  
Low Fat Diet ◽  
Increased Risk ◽  
Coagulant Activity ◽  
High Fat Diets ◽  
Fat Diets

SummaryPreliminary observations have suggested that non-fasting factor VII coagulant activity (FVII:C) may be related to the dietary fat content. To confirm this, we performed a randomised cross-over study. Seventeen young volunteers were served 2 controlled isoenergetic diets differing in fat content (20% or 50% of energy). The 2 diets were served on 2 consecutive days. Blood samples were collected at 8.00 h, 16.30 h and 19.30 h, and analysed for triglycerides, FVII coagulant activity using human (FVII:C) or bovine thromboplastin (FVII:Bt), and FVII amidolytic activity (FVIPAm). The ratio FVII:Bt/FVII:Am (a measure of FVII activation) increased from fasting levels on both diets, but most markedly on the high-fat diet. In contrast, FVII: Am (a measure of FVII protein) tended to decrease from fasting levels on both diets. FVII:C rose from fasting levels on the high-fat diet, but not on the low-fat diet. The findings suggest that high-fat diets increase non-fasting FVII:C, and consequently may be associated with increased risk of thrombosis.

Global Economic Crisis of 2008-2009: Sources and Roots

2009 ◽  
pp. 18-31
Author(s):  
G. Rapoport ◽  
A. Guerts
Keyword(s):  
Oil And Gas ◽  
Trade Deficit ◽  
Developed Countries ◽  
The Other ◽  
Energy Resources ◽  
Market Mechanisms ◽  
Production Output ◽  
The One ◽  
To Receive ◽  
Partial Destruction

In the article the global crisis of 2008-2009 is considered as superposition of a few regional crises that occurred simultaneously but for different reasons. However, they have something in common: developed countries tend to maintain a strong level of social security without increasing the real production output. On the one hand, this policy has resulted in trade deficit and partial destruction of market mechanisms. On the other hand, it has clashed with the desire of several oil and gas exporting countries to receive an exclusive price for their energy resources.

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

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