Germocyte lesions caused by porcine circovirus type 2b in Kunming mice

Abstract

Porcine circovirus type 2 (PCV2) has been known as a causative agent of reproductive failure in the sow. In the present study mouse model was used to investigate PCV2 infection. In order to investigate whether PCV2 can induce lesions of spermatocytes and oocytes, 6 male and 6 female mice were each inoculated intraperitoneally with PCV2b, and 3 male and 3 female mice mock-infected with cell culture supernatant served as controls. Samples of testes and ovaries from PCV2b-inoculated and mock-infected mice were investigated using PCR, histopathological, ultrastructural and immunofluorescent histochemical methods at 14 and 21 day post infection (dpi). The study revealed that in the virus-inoculated mice leydig cells in testes and granulosa cells in ovaries were degenerated, and a small number of spermatocytes and oocytes showed apoptosis. Positive PCV2b antigen signals were also observed in these apoptotic cells. It can be suggested that PCV2 can cause lesions of spermatocyte and oocyte prior to zygotes formation in its host.

Mouse models of porcine circovirus 2 infection

“…Microscopic lesions in PCV2‐infected mice are characterized by the expansion of germinal centers in lymphoid organs, with large numbers of histiocytic cells and lymphoblasts, apoptosis of histiocytic cells in germinal centers, and mild lymphoid depletion of the paracortex . Moreover, PCV2 can also cause lesions of spermatocytes and oocytes prior to zygote formation; Leydig cells in the testes and granulosa cells in the ovaries were degenerated, and a small number of spermatocytes and oocytes underwent apoptosis …”