Numerical chromosomal aberrations in sperm are considered to be a major factor in infertility, early pregnancy loss and syndromes with developmental and cognitive disabilities in mammals, including primates. Despite numerous studies in human and farm animals, the incidence and importance of sperm aneuploidies in non-human primate remains mostly undetermined. Here we investigated the incidence and distribution of sperm aneuploidy in chimpanzees (Pan troglodytes), the species closest to human. We identify evolutionary conserved DNA sequences in human and chimpanzee and selected homologous sub-telomeric regions for all chromosomes to build custom probes and perform sperm-FISH analysis on more than 10,000 sperm nuclei per chromosome. Chimpanzee mean autosomal disomy rate was 0.057 ± 0.02%, gonosomes disomy rate was 0.198% and the total disomy rate was 1.497%. The proportion of X or Y gametes was respectively 49.94% and 50.06% for a ratio of 1.002 and diploidy rate was 0.053%. Our data provide for the first time an overview of aneuploidy in non-human primate sperm and shed new insights into the issues of aneuploidy origins and mechanisms.

Summary Sperm morphometric and morphologic data have been shown to represent useful tools for monitoring fertility, improving assisted reproduction techniques and conservation of genetic material as well as detecting inbreeding of endangered primates. We provide here for the first time sperm morphologic and morphometric data from Cercopithecus neglectus, Cercopithecus cephus, Papio papio and critically endangered Cercopithecus roloway, as well as comparative data from other Cercopithecinae species, i.e. Allochrocebus lhoesti, Mandrillus sphinx and Papio anubis. Following collection from the epididymis, spermatozoa were measured for each species for the following parameters: head length, head width, head perimeter, head area, midpiece length and total flagellum length, and the head volume, ellipticity, elongation, roughness and regularity were then calculated. Our data are consistent with both the general morphology and the morphometric proportions of Cercopithecinae sperm. Some specificities were observed, with C. cephus displaying a narrow head (width = 2.76 ± 0.26 µM) and C. roloway displaying a short midpiece (6.65 ± 0.61 µM). This data set represents an important contribution, especially for Cercopithecus roloway, one of the most endangered monkeys in the world, and further data on additional specimens coupled to data on mating systems and reproductive ecology should allow a better understanding of the mechanisms underlying these morphological differences across primate species.

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Within a month, all five individuals of a pileated gibbon (Hylobates pileatus) family presented the same symptoms: diarrhoea, vomiting and severe apathy. During this first outbreak, three of them died acutely and a fourth died during another outbreak 7 months later. Extensive virology, bacteriology and parasitology undertaken on faeces did not reveal any pathogen. Haematology and extensive biochemistry did not demonstrate any obvious medical disorder. Necropsy revealed a severe proliferative enteropathy, and rare argyrophilic bacteria were noted within the lumen of hyperplastic colonic glands on histology with silver staining. Specific faecal PCR was positive for Lawsonia intracellularis infection. These combined elements led to a strong suspicion of L intracellularis epizooty, despite the absence of large numbers of argyrophilic bacteria, as usually expected in this disease process. L intracellularis has mostly been described in pigs even if reported in a broad range of mammalian species including primates. L intracellularis may be underdiagnosed in zoos as it requires a faecal PCR for identification and silver staining for histological visualisation.