Detection of quantitative trait loci for resistance to gastrointestinal nematode infections in Creole goats

Abstract

This study aimed to identify regions of the genome affecting resistance to gastrointestinal nematodes in a Creole goat population naturally exposed to a mixed nematode infection (Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostomum columbianum) by grazing on irrigated pasture. A genome-wide quantitative trait loci (QTL) scan was performed on 383 offspring from 12 half-sib families. A total of 101 microsatellite markers were genotyped. Traits analysed were faecal egg count (FEC), packed cell volume (PCV), eosinophil count and bodyweight (BW) at 7 and 11 months of age. Levels of activity of immunoglobulin A (IgA) and activity of immunoglobulin E (IgE) anti-Haemonchus contortus L3 crude extracts and adult excretion/secretion products (ESPs) were also analysed. Using interval mapping, this study identified 13 QTL for parasite resistance. Two QTL linked with FEC were found on chromosomes 22 and 26. Three QTL were detected on chromosomes 7, 8 and 14 for eosinophil counts. Three QTL linked with PCV were identified on chromosomes 5, 9 and 21. A QTL for BW at 7 months of age was found on chromosome 6. Lastly, two QTL detected on chromosomes 3 and 10 were associated with IgE anti-L3, and IgE anti-ESP was linked with two QTL on chromosomes 1 and 26. This study is the first to have identified regions of the genome linked with nematode resistance in a goat population using a genome scan. These results provide useful tools for the understanding of parasite resistance in small ruminants.

Genome-wide association study of conformation and milk yield in mixed-breed dairy goats

“…Quantitative trait loci for traits such as birth and weaning weight (Mohammad Abadi et al, 2009;Visser et al, 2013), hair fiber characteristics (Cano et al, 2007;Visser et al, 2011), growth (Mohammad Abadi et al, 2009), body conformation (Marrube et al, 2007), parasite resistance (Bolormaa et al, 2010;De La Chevrotière et al, 2012), milk traits (Roldán et al, 2008), and α S1 -casein (Sacchi et al, 2005;Hayes et al, 2006;Dagnachew et al, 2011) have been identified in goats using microsatellite markers. With the availability of the Illumina Caprine 50K BeadChip (Illumina Inc., San Diego, CA;Tosser-Klopp et al, 2012, 2014, it is now possible to perform genome-wide scans in goats Genome-wide association study of conformation and milk yield in mixed-breed dairy goats with much greater resolution.…”

Immunogenomics of gastrointestinal nematode infection in ruminants – breeding for resistance to produce food sustainably and safely

“…There is extensive evidence in the literature for a definitive role for IgE in the regulation of FEC in numerous breeds of sheep and goat . In all studies, parasite‐specific IgE antibodies were negatively correlated with FEC; of concern, however, is that variable genetic correlations with body weight were observed in both sheep (to T. circumcincta ;) and goats (to H. contortus ;). This is potentially due to the mast cell degranulation event affecting the robustness of the tight‐junctional complex at the mucosal surface, allowing protein deficiencies to develop;…”

“…The action of IgE is through a classical type I hypersensitivity reaction that is mediated by mast cell proliferation/degranulation in the mucosa of the GIT following exposure of the mast cells to L3 antigen . There is extensive evidence in the literature for a definitive role for IgE in the regulation of FEC in numerous breeds of sheep and goat . In all studies, parasite‐specific IgE antibodies were negatively correlated with FEC; of concern, however, is that variable genetic correlations with body weight were observed in both sheep (to T. circumcincta ;) and goats (to H. contortus ;).…”

“…[8][9][10][11] In all ruminants studied to date, resistance to GIN infection has been shown to be a moderately heritable trait with most heritability estimates ranging between 0.2 and 0.4 in sheep, cattle and goats. [12][13][14][15][16][17][18][19][20][21] In addition, a variety of breeds have been identified that are relatively more resistant to GIN infection. [22][23][24] These observations have stimulated the development of breeding strategies, in combination with T A B L E 1 Nematodes identified in farmed ruminants Taylor et al 142 ).…”

The Application of Genomic Technologies to Investigate the Inheritance of Economically Important Traits in Goats

“…A bibliographic search at NCBI Pubmed Database (http://www.ncbi.nlm.nih.gov/) revealed few publications where caprine QTL are described (a representative list can be found at Table 1). For instance, De la Chevrotière et al [2] identified 13 QTL for resistance to gastrointestinal nematode infections in Creole goats by analysing 101 microsatellites. Quantitative trait loci affecting mohair [3,4] and conformation traits [5] as well as preweaning growth [6] have also been reported in Angora goats.…”