Characterization and transcription of non-classical class I major histocompatibility complex (MHC) genes in buffaloes.

The objective of the present study was to characterize non-classical class I major histocompatibility complex (MHC) genes in buffaloes and evaluate the expression of these genes in different tissue components of the placenta of buffaloes during pregnancy and in trophoblastic cells after stimulation using lipopolysaccharide (LPS). To do this, DNA was extracted from the blood of buffaloes and was subjected to PCR testing and sequencing of the genes NC3 and MICB. The RNA extracted from the placentome and intercotyledonary region of buffaloes in their first (n = 6), second (n = 6) and third (n = 6) trimesters of gestation was subjected to real-time PCR. Explants were created using the chorioallantoic membrane and two experimental groups were established: control and stimulated with LPS for four hours to evaluate the gene expression profile. Analysis on the sequences obtained showed that the genes NC3 and MICB of buffaloes were homologous with those of cattle, with high similarity in the analysis on the sequence variation pattern. The gene expression analysis showed that the genes assessed were transcribed at stages and in placental tissue that differed from what was seen in cattle. The transcription of these genes varied in the tissues studied, with greater transcription of MICB in the intercotyledonary region over the first third of gestation, while the genes studied in the placentome presented low rates of transcription. The trophoblastic cells of the chorioallantoic membrane stimulated with LPS for six hours did not present non-classic MFC-I transcription alterations. The present study therefore provides additional knowledge regarding the immune regulation of placental tissues of buffaloes.