EN
INTRODUCTION: Advanced paternal age (APA) is a risk factor for conceiving children with autism spectrum disorders. Social deficits, altered communication and repetitive behaviors are key diagnostic symptoms of autism. AIM(S): In this study we used a mouse model to investigate the effects of APA on offspring communicative behaviors - ultrasound vocalization (USV). METHOD(S): 4–5 month old Swiss males conceived by fathers of 3 different ages – 12 month old (Advanced Paternal Age, APA n=32), 2 month old (Young Paternal Age, YPA-1 n=17), 5 month old (YPA-2 n=16) - and mothers aged 3 months, were subjected to the resident-intruder test to evoke USVs emission. The tested mouse, which had been previously isolated for 7 days, was habituated for 7 minutes to a soundproof chamber. An intruder (C57/CBA 2–4 month old male) was then introduced to the home-cage of the tested mouse. Ultrasound vocalizations were recorded for 180 s using an ultrasound-sensitive microphone placed 10 cm above the cage and were analysed using Avisoft SASLab software. RESULTS: There were no statistically significant differences among groups in the latency to start USV emission. The percentage of vocalizing mice in APA was 87,5%, YPA‑1 – 53% and YPA‑2 – 87,5%. APA mice displayed increased number of USVs (p=0.003), increased duration and decreased sound amplitude of USVs, compared to YPA mice (p<0.001 and p<0.0001, respectively). No significant changes were observed in minimum and maximum USV frequencies. Furthermore, USVs were classified based on their waveform pattern. Mice conceived by differently aged fathers exhibited different repertoires of vocalizations. CONCLUSIONS: Overall, paternal age affects USV patterns in adult offspring. Heritable de novo mutations and/ or epigenetic alterations transmitted by the sperm may underlie the phenotypic changes observed in offspring. FINANCIAL SUPPORT: This work was supported by the Polish National Science Center (2014/15/D/NZ4/04274) and in part by Statutory Research Fund of the Department of Animal and Human Physiology of University of Gdansk.