L. Paetzold

Radiation hybrid mapping and comparative sequence analysis of bovine RIG-I and MAVS genes

Retinoic acid inducible gene I (RIG-I) and mitochondrial antiviral signaling (MAVS) proteins have recently been found to operate in a pathway for the detection and subsequent elimination of replicating viral genomes. Because of this innate immunity role, RIG-I and MAVS are candidates for studies of disease resistance. The objectives of this work were to (1) radiation hybrid (RH) map bovine RIG-I and MAVS and (2) perform comparative sequence analysis of partial genomic sequence from each gene. Using a bovine 5000rad RH panel, RIG-I was localized to BTA08 (LOD > 12) and MAVS was localized to BTA13 (LOD > 12). RIG-I exon 14 and partial MAVS exon five were sequenced in nine breeds and compared with available sequence from the Bovine Genome Project. RIG-I exon 14 and partial MAVS exon five were conserved in all samples examined. One T–A transversion SNP was found in intronic sequence downstream of RIG-I exon 14.

Assessments of Temporal Variations in Haplotypes of ‘Candidatus Liberibacter solanacearum’ and Its Vector, the Potato Psyllid, in Potato Fields and Native Vegetation

Abstract The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera:Triozidae), had been known for nearly a century to cause psyllid yellows of solanaceous crops. However, it has only been a decade since the insect was discovered to transmit the bacterium ‘Candidatus Liberibacter solanacearum’ (Lso), which putatively causes potato zebra chip disease. This project was initiated to quantify temporal incidences of haplotypes of the psyllid (Central, Southwestern, and Western) and Lso (A, B) in potato fields and in native vegetation. Psyllids were collected from native vegetation in Texas (2011–2014), and from potato fields in Texas and New Mexico (2014–2017). Psyllids were tested for Lso and haplotypes of both psyllid and Lso. In Texas, the Central psyllid haplotype was overwhelmingly dominant both in potato fields and in native vegetation regardless of location and time of collection. However, in New Mexico potato fields, although the Southwestern haplotype was overall dominant, the ratios of individual haplotypes varied among years and within a season. The Southwestern psyllid haplotype was greater in incidence than the Central early but declined later in the season in each of the 4 yr, while the Central haplotype was low in incidence early but increased over time. Lso was detected in all three psyllid haplotypes representing the first report in Southwestern psyllid haplotype. InTexas, Lso haplotype A was more frequently detected than B, but in New Mexico the incidence of positive psyllids was not high enough to make definitive conclusions regarding predominant Lso haplotype.