Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, P. R. China.
Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, Nanjing, 210014, P. R. China.
BMC Vet Res. 2023 Jul 28;19(1):97. doi: 10.1186/s12917-023-03669-2.
Porcine circovirus-like virus P1 is the animal virus with the smallest genome discovered so far, and it has become widely distributed in the Chinese mainland in recent years.
In this study, a BALB/c mouse model was used to reveal P1 infection in female reproductive systems and the vertical transmission of the virus. The female reproductive system, including the ovary and uterus, was harvested on day 14 postinfection and examined for pathological lesions. One-day-old mice without colostrum born from infected or uninfected mothers were collected, and P1 virus distribution in the different organs was investigated. During the trials, all the mice showed no clinical symptoms or gross lesions. However, stillbirth did occur in groups infected with the P1 virus. P1 nucleic acid was detected in the heart, liver, spleen, lung, kidney, and brain tissues of 1-day-old mice born from infected mice. Microscopic lesions in P1-infected female mice were characterized by necrosis of the ovarian follicular granulosa cells and abscission, follicular atresia, necrosis of the endometrial epithelial and uterine glandular epithelial cells, and hyperplasia of the squamous endometrial epithelium. The spermatocytes in the seminiferous tubules of the infected male mice were disorderly arranged, and the germ and Sertoli cells were shed, necrotic, and decreased in number. Immunohistochemical results identified P1-positive particles in the nucleus and cytoplasm of cells from the ovary and uterus of female mice.
This study shows that the P1 virus could cause pathological damage to the reproductive system of female mice and could be transmitted vertically.
猪圆环病毒样病毒 P1 是迄今为止发现的基因组最小的动物病毒，近年来已在中国大陆广泛分布。
本研究采用 BALB/c 小鼠模型揭示了 P1 感染雌性生殖系统及其垂直传播。在感染后第 14 天收获雌性生殖系统（包括卵巢和子宫），并检查其病理损伤。收集来自感染或未感染母亲的 1 日龄无初乳的小鼠，研究病毒在不同器官中的分布。试验期间，所有小鼠均未出现临床症状或明显病变。然而，感染 P1 病毒的小鼠仍发生死胎。从感染 P1 病毒的小鼠所生的 1 日龄小鼠的心脏、肝脏、脾脏、肺脏、肾脏和脑组织中检测到 P1 核酸。P1 感染雌性小鼠的微观病变特征为卵巢卵泡颗粒细胞坏死和脱落、卵泡闭锁、子宫内膜上皮和子宫腺上皮细胞坏死以及鳞状子宫内膜上皮增生。感染雄性小鼠的曲细精管中的精母细胞排列紊乱，生殖细胞和支持细胞脱落、坏死和数量减少。免疫组化结果显示，雌性小鼠卵巢和子宫细胞的核和细胞质中存在 P1 阳性颗粒。
本研究表明 P1 病毒可引起雌性小鼠生殖系统的病理损伤，并可垂直传播。
