PhD student Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland Olsztyn, Warminsko-Mazurskie, Poland
Abstract Authors: Dominika Kawka1, Maria Guzewska1, Alicja Zochowska-Klepanska1, Monika M. Kaczmarek1
1. Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland
Abstract Text: Nutrition significantly influences various aspects of reproductive outcomes, including gamete quality, hormonal balance, and the progression of pregnancy. Emerging research explores gender-specific mechanisms through which dietary habits may shape individual reproductive health and leave a lasting impact on the fertility of subsequent generations. In this study, we investigated the impact of malnutrition during the early postnatal period on the reproductive performance and fertility of female and male mice, spanning two successive generations.
Newborn pups (F1) were assigned to either the control group (CON), where mothers were fed ad libitum, or the lactation undernutrition group (LUN), where mothers were provided with 50% of the daily portion of chow consumed by control dams. After weaning (postnatal day 21 = PND21), F1 offspring was fed ad libitum. Sexually mature F1 mice were bred in three different combinations: CON female x CON male (CC), LUN female x CON male (LC) and LUN female x LUN male (LL), to generate F2 offspring not directly exposed to undernutrition. A morphometric analysis of ovaries and testes was performed at PND21, while follicle count and daily sperm production were assessed in adults. Upon reaching sexual maturity, estrus cycles were monitored in F1 and F2 females. The hormonal status of both sexes was evaluated by measuring androstenedione, progesterone, luteinizing hormone (LH), and testosterone (males only) in blood plasma. To assess reproductive performance over time, breeding pairs from the F1 and F2 generations were monitored for the number of pups and litters over a 20-week period.
LUN females displayed irregular initial estrus cycles compared to CON. At PND21, their ovaries exhibited smaller sizes with fewer antral follicles, a trend that persisted into adulthood with decreased follicle counts. Furthermore, LUN females showed lower androstenedione levels and elevated LH levels at PND21, with lower progesterone levels observed in sexually mature animals. Notably, these effects were not detected in the second generation of female mice. The scenario differed significantly for males. Early-life malnutrition affected the morphological appearance of the testes. Both LUN and LL males exhibited decreased daily sperm production compared to the CON and CC groups, respectively. Additionally, LUN and LL males displayed lower levels of androstenedione and testosterone at PND21, along with elevated levels of LH. LUN females had limited reproductive capacity after 15 weeks of breeding, whereas LUN males had a decreased total number of delivered offspring over time compared to control pairs. LL females paired with CC males appeared to have slightly better reproductive performance over time than LL males paired with CC females.
In summary, early-life malnutrition in the F1 generation impairs their reproductive performance. Notably, adverse effects on gamete production and hormonal balance in the next generation (F2) were observed only in males. This study highlights the crucial role of parental nutritional history in determining the reproductive performance in a sex-specific manner.
Research supported by Polish National Science Centre [2018/31/B/NZ4/03527].
