Dietary n-3 but not n-6 fatty acids modulate anthropometry and fertility indices in high-fat diet fed rats: a two-generation study

Effects of maternal preconception high-fat diet on the fertility of dams and on the somatic parameters and reflex ontogeny of their male offspring

BACKGROUND

Female consumption of a high-fat diet (HFD) may cause fertility issues and affects offspring development.

OBJECTIVE

Evaluate the acute maternal preconception intake of a HFD on the fertility and reproduction parameters of breeding females; and on the somatic parameters and reflex ontogeny of male offspring.

METHODS

Twenty-four rats were randomized into control (PC; n=12) and high-fat diet group (PHF; n=12) that consumed their respective diets during the 23-day preconception period. After that, 6 rats per group underwent oral glucose tolerance and insulin tolerance tests and were euthanized. The remaining rats were mated, during gestation and lactation, both groups ate a control diet. After birth, the male offspring's somatic parameters and reflexes were assessed.

RESULTS

The preconception diet caused dyslipidemia in the PHF. The PHF uterus exhibited a higher SFA (50.74 ± 0.32 %), a lower PUFA concentration (35.59 ± 0.33 %), and an increase in arachidonic acid (2.48 ± 0.03 %). PHF rats had hypertrophy in the endometrium, and ovaries with a higher quantity of corpora albicans and immature primordial follicles. The offspring of PHF rats had greater weight (6.70 ± 0.82 g), nasal-anal length (4.93± 0.27 cm), and tail length (1.74 ± 0.12 cm) on the first day of life, and had improved righting reflex, but delayed negative geotaxis reflex.

CONCLUSIONS

An acute maternal preconception HFD induced a pro-inflammatory fatty acid profile and changed structure in uterus, altered ovarian follicle profile. Also, potential interference in the size of the pups at birth and in brain development of male offspring.

Lower Plasmatic Levels of Saturated Fatty Acids and a Characteristic Fatty Acid Composition in the Ovary Could Contribute to the High-Fertility Phenotype in Dummerstorf Superfertile Mice

In recent decades, fertility traits in humans as well as in farm animals have decreased worldwide. As such, it is imperative to know more about the genetics and physiology of increased or high fertility. However, most of the current animal models with reproductive phenotypes describe lower fertility or even infertility (around 99%). The “Dummerstorf high-fertility lines” (FL1 and FL2) are two unique mouse lines selected for higher reproductive performances, more specifically for higher number of pups per litter. We recently described how those superfertile mice managed to increase their reproductive phenotype by doubling the ovulation rate and consequently the litter size compared to the unselected mice of the same founder population. FLs show an unusual estrous cycle length and atypical levels of hormones that link reproduction and metabolism, such as insulin in FL1 and leptin in FL2. Moreover, we described that their higher ovulation rate is mostly due to a higher quality of their oocytes rather than their sheer quantity, as they are characterized by a higher quantity of high-quality oocytes in antral follicles, but the quantity of follicles per ovary is not dissimilar compared to the control. In the present study, we aimed to analyze the lipid composition of the fertility lines from plasma to the gonads, as they can connect the higher reproductive performances with their metabolic atypicalities. As such, we analyzed the fat content of FLs and fatty acid composition in plasma, liver, fat, oocytes of different quality, and granulosa cells. We demonstrated that those mice show higher body weight and increased body fat content, but at the same time, they manage to decrease the lipid content in the ovarian fat compared to the abdominal fat, which could contribute to explaining their ovarian quality. In addition, we illustrate the differences in fatty acid composition in those tissues, especially a lower level of saturated fatty acids in plasma and a different lipid microenvironment of the ovary. Our ongoing and future research may be informative for farm animal biology as well as human reproductive medicine, mostly with cases that present characteristics of lower fertility that could be reversed following the way-of-managing of Dummerstorf high-fertility lines.

Three-Generation Study of Male Rats Gestationally Exposed to High Butterfat and Bisphenol A: Impaired Spermatogenesis, Penetrance with Reduced Severity

Gestational high butterfat (HFB) and/or endocrine disruptor exposure was previously found to disrupt spermatogenesis in adulthood. This study addresses the data gap in our knowledge regarding transgenerational transmission of the disruptive interaction between a high-fat diet and endocrine disruptor bisphenol A (BPA). F0 generation Sprague-Dawley rats were fed diets containing butterfat (10 kcal%) and high in butterfat (39 kcal%, HFB) with or without BPA (25 µg/kg body weight/day) during mating and pregnancy. Gestationally exposed F1-generation offspring from different litters were mated to produce F2 offspring, and similarly, F2-generation animals produced F3-generation offspring. One group of F3 male offspring was administered either testosterone plus estradiol-17β (T + E2) or sham via capsule implants from postnatal days 70 to 210. Another group was naturally aged to 18 months. Combination diets of HFB + BPA in F0 dams, but not single exposure to either, disrupted spermatogenesis in F3-generation adult males in both the T + E2-implanted group and the naturally aged group. CYP19A1 localization to the acrosome and estrogen receptor beta (ERbeta) localization to the nucleus were associated with impaired spermatogenesis. Finally, expression of methyl-CpG-binding domain-3 (MBD3) was consistently decreased in the HFB and HFB + BPA exposed F1 and F3 testes, suggesting an epigenetic component to this inheritance. However, the severe atrophy within testes present in F1 males was absent in F3 males. In conclusion, the HFB + BPA group demonstrated transgenerational inheritance of the impaired spermatogenesis phenotype, but severity was reduced in the F3 generation.