Bovine herpesvirus type 1 in cumulus-oocyte complexes collected from naturally infected cows

Oliveira, André Alves de; Heinemann, Marcos Bryan; Cortéz, Adriana; Nascimento, P. M. P.; Leite, Rômulo Cerqueira; Viana, J. H. M.

doi:10.1590/s0100-204x2016000500031

Cited by 1 publication

(1 citation statement)

References 13 publications

(13 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Researchers using the polymerase chain reaction (PCR) test to detect BoHV-1 DNA have concluded that the risk of transmission of BoHV-1 by COCs and follicular fluid from seropositive cows without clinical symptomatology is irrelevant (Oliveira et al 2016), since the presence of viral DNA was not observed in any of their tested samples.…”

Section: Discussionmentioning

confidence: 99%

Impairment on nuclear maturation rate in oocytes from cows naturally infected by bovine herpesvirus 1 (BoHV-1)

et al. 2018

View full text Add to dashboard Cite

Bovine herpesvirus 1 (BoHV-1) is an important bovine pathogen that is responsible for causing respiratory diseases and reproductive failures. The presence of BoHV-1 in an in vitro embryo production system affects fertilization, maturation, and embryonic development. The objective of this study was to evaluate the developmental capacity of oocytes from naturally infected cows with no reproductive history. Moreover, this study investigated the presence of viral DNA in cumulus oophorus complexes (COCs). Experimental groups were differentiated by titrating the antibodies detected through seroneutralization assays, establishing three groups: seronegative animals (titer lower than 2), low titer (2 to 8), and animals with a titer above or equal to 16. COCs were obtained from 15 donors during 22 sessions of ultrasound-guided follicular aspiration. DNA was extracted from a pool of COCs obtained from all aspirations from the same donor as well as from whole blood and nested PCR reactions were performed. Only COCs with a compact layer of cumulus cells, an intact zona pellucida, and homogeneous cytoplasm were selected for in vitro culture and evaluation of nuclear maturation rate. After culturing for 24 hours, the oocytes were fixed and stained to evaluate the meiotic cell cycle stage. Oocytes that showed a chromosomal configuration in metaphase II were considered to have reached nuclear maturation. Compared with the other groups, the oocyte nuclear maturation rate in animals with a titer greater than or equal to 16 (50%) was compromised (P< 0.05). However, the viral titer did not influence the maturation rate of bovine oocytes in animals exhibiting low titration (62.2%) when compared with the control group (76.7%). Viral DNA was not observed in the blood samples but was detected in the COC pool from three seropositive donors. In view of the results obtained, we conclude that natural infections by the BoHV-1 virus can compromise the nuclear maturation rate in cows, depending on the titration levels of antibodies against the virus. Moreover, viral DNA could be present in COCs, contradicting the hypothesis that seropositive animals with no history of clinical symptomatology pose a negligible risk of transmitting BoHV-1 by COCs.

show abstract

Section: Discussionmentioning

confidence: 99%