Food restriction affects reproduction and survival of F1 and F2 offspring of Rat-like hamster (Cricetulus triton)

Amino acid quality modifies the quantitative availability of protein for reproduction in Drosophila melanogaster

Diet composition, especially the relative abundance of key macronutrients, is well known to affect animal wellbeing by changing reproductive output, metabolism and length of life. However, less attention has been paid to the ways the quality of these nutrients modify these macronutrient interactions. Nutritional Geometry can be used to model the effects of multiple dietary components on life-history traits and to compare these responses when diet quality is varied. Previous studies have shown that dietary protein quality can be increased for egg production in Drosophila melanogaster by matching the dietary amino acid proportions to the balance of amino acids used by the sum of proteins in the fly's in silico translated exome. Here, we show that dietary protein quality dramatically alters the effect of protein quantity on female reproduction across a broad range of diets varying in both protein and carbohydrate concentrations. These data show that when sources of ingredients vary, their relative value to the consumer can vastly differ and yield very different physiological outcomes. Such variations could be particularly important for meta analyses that look to draw generalisable conclusions from diverse studies.

Maternal energy insufficiency affects testicular development of the offspring in a swine model

We determined the effects of insufficient maternal energy on testicular development in offspring in a swine model. Thirty-six sows were divided into control (CON) and low-energy diet (LE) groups during gestation. We observed that the number of Sertoli, germ, and Leydig cells in the offspring of the CON group were significantly higher than those in the LE group at 28 and 120 d after birth. Furthermore, the percentage of apoptotic testis cells was significantly higher in the offspring of the LE group than in the CON group. Transcriptome analysis of differentially expressed mRNAs and long noncoding RNAs in offspring testes indicated that these RNAs were mainly involved in lipid metabolism, apoptosis, cell proliferation, and some pivotal regulatory pathways. Results revealed that AMPK-PI3K-mTOR, MAPK, and oxidative phosphorylation signaling pathways play an important role in mediating the programming effect of insufficient maternal energy on testicular development, and that this effect occurs mainly at an early stage in life. mRNA and protein expression analyses confirmed the importance of certain signaling pathways in the regulation of testicular development. This study provides insights into the influence and possible mechanism underlying the effect of inadequate maternal energy intake on testicular development in the offspring.

Interpretation of Fiber Supplementation on Offspring Testicular Development in a Pregnant Sow Model from a Proteomics Perspective

To study the effects of maternal fiber supplementation during pregnancy on the testicular development of male offspring and its possible mechanisms, 36 sows (Landrace × Yorkshire) were allocated to either a control diet (n = 18) or a fiber diet (the control diet supplemented with 22.60 g/kg inulin and 181.60 g/kg cellulosic; n = 18) during pregnancy. The body and testes weight of the offspring, 7-day-old piglets, was recorded. Testes were collected for further analyses. Results showed that the testicular organ index and the number of spermatogonia in single seminiferous tubule were higher in piglets from the fiber group than from the control group (p < 0.05). In addition, a significant increase in the concentration of glucose, lactate, and lipids in the testes was found in the fiber group (p < 0.05). Proteomic analysis suggested that there were notable differences in glucolipid transport and metabolism, oxidation, and male reproduction-related proteins expression between the two groups (p < 0.05). Results revealed that the most enriched signaling pathways in the fiber group testes included starch and sucrose metabolism, fatty acid metabolism, glutathione metabolism, and the renin-angiotensin system. mRNA expression analyzes further confirmed the importance of some signaling pathways in maternal fiber nutrition regulating offspring testicular development. Our results shed new light on the underlying molecular mechanisms of maternal fiber nutrition on offspring testicular development and provided a valuable insight for future explorations of the effect of maternal fiber nutrition on man reproduction.

Intergenerational response of steroidogenesis-related genes to maternal malnutrition

We sought to examine whether rat maternal food restriction (MFR) affects the expression of steroidogenesis-related genes Cyp19, Cyp17a1, Insl3 and Gdf-9 in the ovaries of offspring from the first (FRG1) and second (FRG2) generations at pre-pubertal age (week 4) and during adulthood (week 8). At week 4, MFR significantly increased the expression of RNAs for all analyzed genes in both FRG1 and FRG2 females, which may indicate that MFR affects the onset of the reproductive lifespan, by inducing early pubertal onset. At week 8, the Cyp19 gene was still upregulated in MRF-subjected animals (Cyp19: P=0.0049 and P=0.0508 in FRG1 and FRG2, respectively), but MFR induced a significant decrease in Cyp17 and Gdf-9 gene expression in the offspring of both FRG1 and FRG2 females when compared with the controls (Cyp17: P=0.0018 and P=0.0016, respectively; Gdf-9: P=0.0047 and P=0.0023, respectively). This suggests that females at week 8, which should normally be in their optimal reproductive capacity, experience premature ovarian aging. At week 4, the activation of Cyp19 and Cyp17 was higher in the FRG1 ovaries than in the FRG2 ovaries, whereas the extent of Insl3 and Gdf-9 activation was lower in the FRG1 ovaries. This may indicate that FRG2 females were more vulnerable to MFR than their mothers (FRG1) and grandmothers, which is consistent with the 'predictive adaptive response' hypothesis. Our findings reveal that MFR may induce intergenerational ovarian changes as an adaptive response to ensure reproductive success before death.

ARECOLINE CANNOT ALTER PINEAL-TESTICULAR RESPONSES TO METABOLIC STRESS IN WISTAR RATS

Context

Betel nut is consumed by millions of people for stress reduction and increased capacity to work. One of its components is arecoline which is useful for Alzheimer and schizophrenia; it also influences endocrine and gonadal functions.

Objective

Objective is to examine whether arecoline can influence pineal-testicular function in metabolic stress.

Design

Rats were deprived of food or water or treated them with arecoline, each separately for 5 days.

Subjects

Pineal and testis with sex accessories were studied.

Methods

Ultrastructural (pineal, testis, Leydig cells and prostate), hormonal (melatonin and testosterone) and other parameters (fructose and sialic acid) were examined. Pineal indoleamines were quantitated by fluorometric method; testosterone by ELISA, and carbohydrate fractions by spectrophotometric methods.

Results

Inanition/ water deprivation caused pineal stimulation ultrastructurally (with enlarged synaptic ribbons) and elevation of melatonin level, but reproductive dysfunction by ultrastructural degeneration of Leydig cells and prostate with fall of testosterone, fructose and sialic acid concentrations. Arecoline treatment showed reversed changes to those of metabolic stress, but arecoline treatment in metabolic stress showed same results as in metabolic stress.

Conclusion

The findings suggest that arecoline cannot alter the action of metabolic stress on pineal-testicular activity in rats.

An integrative overview of the role of gonadotropin-inhibitory hormone in behavior: applying Tinbergen's four questions

The integration of various fields of investigation is of key importance to fully comprehending endocrine function. Here, I enact the theoretical framework of Nikolaas Tinbergen's four questions for understanding behavior to help bridge the wide gap that exists between our relatively reductionist molecular knowledge of a particular neurohormone, gonadotropin-inhibitory hormone (GnIH), and its place in animal behavior. Hypothalamic GnIH, upon its discovery in 2000, was so named because of its inhibitory effect on the release of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), from the pituitary. Because gonadotropins are necessary for reproduction, this finding stimulated questions about the functional significance of GnIH in reproduction and sexual behavior. After over a decade of research, invaluable knowledge has been gained regarding the mechanistic attributes of GnIH (mammalian homolog, RFamide-related peptide (RFRP)) in a variety of vertebrate species. However, many questions remain regarding the effect of the environment on GnIH and the subsequent effects of GnIH on behavior. I review the role of GnIH in shaping behavior using the framework of Tinbergen's four questions of mechanism, ontogeny, function and phylogeny. The studies I review were conducted in various species of mammals, birds, and in one species of fish. Because GnIH can play a role in mediating behaviors such as those important for reproduction, sociality, feeding, and the stress response in a variety of species, an integrative approach to the study of GnIH will help provide a multipronged schema for answering questions of GnIH function. By using the framework highlighted by Tinbergen's four questions, we will deepen and enhance our knowledge of the role of hormones in behavior from the point of view of the mechanisms involved.

Reproductive resilience to food shortage in a small heterothermic primate

The massive energetic costs entailed by reproduction in most mammalian females may increase the vulnerability of reproductive success to food shortage. Unexpected events of unfavorable climatic conditions are expected to rise in frequency and intensity as climate changes. The extent to which physiological flexibility allows organisms to maintain reproductive output constant despite energetic bottlenecks has been poorly investigated. In mammals, reproductive resilience is predicted to be maximal during early stages of reproduction, due to the moderate energetic costs of ovulation and gestation relative to lactation. We experimentally tested the consequences of chronic-moderate and short-acute food shortages on the reproductive output of a small seasonally breeding primate, the grey mouse lemur (Microcebus murinus) under thermo-neutral conditions. These two food treatments were respectively designed to simulate the energetic constraints imposed by a lean year (40% caloric restriction over eight months) or by a sudden, severe climatic event occurring shortly before reproduction (80% caloric restriction over a month). Grey mouse lemurs evolved under the harsh, unpredictable climate of the dry forest of Madagascar and should thus display great potential for physiological adjustments to energetic bottlenecks. We assessed the resilience of the early stages of reproduction (mating success, fertility, and gestation) to these contrasted food treatments, and on the later stages (lactation and offspring growth) in response to the chronic food shortage only. Food deprived mouse lemurs managed to maintain constant most reproductive parameters, including oestrus timing, estrogenization level at oestrus, mating success, litter size, and litter mass as well as their overall number of surviving offspring at weaning. However, offspring growth was delayed in food restricted mothers. These results suggest that heterothermic, fattening-prone mammals display important reproductive resilience to energetic bottlenecks. More generally, species living in variable and unpredictable habitats may have evolved a flexible reproductive physiology that helps buffer environmental fluctuations.

Testosterone, social and sexual behavior of perinatally and lifelong calorie restricted offspring

Calorie restriction (CR) during sensitive perinatal periods has consistently been demonstrated to alter the development of a variety of physiological systems, which consequently affect behavior. This study compared the social behavior and sexual behavior of the adult male offspring of mothers administered a 25% CR at one of four times in the perinatal period: a brief period preconception, during gestation, during lactation, or a lifelong restriction (beginning at conception and continuing throughout life). Levels of serum testosterone were also determined in these animals. Social interaction increased in the gestation and lifelong CR groups. The lifelong group also exhibited more dominant type behaviors. CR during preconception and lactation resulted in offspring that displayed an enhanced and more efficient copulatory pattern compared to all other conditions. This was demonstrated by a reduced frequency of intromissions, shorter latency to ejaculation, and a greater frequency of ejaculations by the preconception and lactation group compared to some, if not all of the other CR groups and controls. Serum testosterone was significantly higher in the preconception group compared to controls. These findings indicate that CR during specific periods of development can differentially alter the social behavioral phenotype and hormone levels in adulthood.

Effect of maternal food restriction during gestation on early development of F1 and F2 offspring in the rat-like hamster (Cricetulus triton)

Maternal food restriction (FR) may have strong and long-term effects on body weight, brain and behavior development of offspring. However, it is still not well understood whether such an effect is carried over to the next generation. Our objective was to examine the differences of maternal behavior, body growth, cranial growth and early development of F1 and F2 offspring of rat-like hamsters between a FR group and a control group. Results show that FR has a significant influence on maternal gathering behavior. The body weight of F1 offspring was significantly lower in the food-restricted group compared with that of the control animals, while the body weight of food-restricted F2 offspring was not significantly different from that of the control group. The physical development and neurodevelopment of food-restricted F1 and F2 offspring were significantly delayed compared to the controls. These results suggest that FR in female rat-like hamsters affected negatively the body growth of F1 offspring, and the physical and neurodevelopment of both F1 and F2 offspring. The effect of maternal FR on F2 offspring was smaller than that on F1 offspring. These factors may, in turn, play an important role in the population regulation of this species.