Idiopathic pulmonary arterial hypertension syndrome (IPAH) is a disease of humans and chickens that results from chronic high pulmonary arterial pressure. IPAH in broiler chickens results in right-sided congestive heart failure leading to ascites that, if not aggressively treated, will result in death. We have been mapping chicken genes affecting resistance or susceptibility to IPAH. Previously, we identified two regions on Gga9 and one on Gga27 that show significant linkage disequilibrium to IPAH in our susceptible line. Within these regions we identified three candidate genes that are known to be related to susceptibility to pulmonary hypertension in humans. Those genes are angiontensinogen converting enzyme (ACE), 5-hydroxytryptamine (serotonin) receptor 2B(HTR2B), and a type 1 angiotensin II receptor (AGTR1). We are examining the expression of these three genes in chicken IPAH using reverse transcriptase quantitative PCR. Initial analyses suggest differences in the expression levels for two of the candidate genes in whole blood RNAs. Ribosomal Protein 14 (RPS14), β2-microglobulin (β2M), TATA Binding Protein (TBP), and RNA polymerase 2B (RP2B) were used as reference genes for qPCR. RPS14 and RP2B were found to give the most consistent qPCR delta-Ct values relative to TBP and β2M . We are expanding the analyses to include increased numbers of samples and a wider range of tissues specifically lung, kidney, liver, and heart.
-This work was supported by grants from the Arkansas Biosciences Institute and NIH/NHLBI Grant 1R15HL092517 01.