Variant discovery in genes identified as differentially expressed genes between the abomasal lymph node transcriptome of resistant and susceptible adult sheep to teladorsagia circumcincta infection

Abstract

Gastrointestinal nematode infections are one of the major health issues facing grazing sheep populations and it incurs on major economic losses for sheep breeders. The resistance/susceptibility trait appears to be a highly complex trait (Behnke et al. 2003; Dominik 2005). In sheep resistance to nematode infection shows a moderate level of heritability (range 0.3-0.6) (Stear et al. 2001). Several QTL mapping studies have tried to identify genomic regions and mutations that influence resistance to nematode infection (Atlija et al. 2016; Coltman et al. 2001; Gutiérrez-Gil et al. 2009; Sayers et al. 2005), although the detection of causal mutations for this trait is still a challenge for the research community. The recently available RNA-seq technology provides the opportunity to extract highthroughput transcriptome data from a specific tissue to perform gene quantification, differential gene expression and detection of variants (SNPs and indels), which could be assessed as potential causal mutations (Hudson, Dalrymple, and Reverter 2012). A previous study of our research group has identified a list of 106 differential expression genes (DEGs) based on RNA-Seq dataset obtained from the abomasal lymph nodes of 12 adult sheep, previously classified as resistant or susceptible to GIN infection based on an artificial infection with T. circumcincta larvae Chitneedi et al. (2018). In the present study we present a detailed study of the variants mapping within the list of DEGs previously reported in that study. Thus, the present study provides a list of functionally relevant variants that could underlie the genetic control of resistance/susceptibility to T. circumcincta in adult sheep. Financiado por la Junta de Castilla y León (Conserjería de Educación) y Fondo Social Europeo (Ref. LE248U14). Ejecución: Universidad de León. Dpto. Producción Animal. Investigador Principal: Dr. Beatriz Gutierrez Gil