Al Kalaldeh, Mohammad; Gibson, John; Lee, Sang Hong; Gondro, Cedric; van der Werf, Julius H J

Author(s)

Al Kalaldeh, Mohammad

Gibson, John

Lee, Sang Hong

Gondro, Cedric

van der Werf, Julius H J

Publication Date

2019-07-03

Abstract

Background: This study aimed at identifying genomic regions that underlie genetic variation of worm egg count, as an indicator trait for parasite resistance in a large population of Australian sheep, which was genotyped with the highdensity 600 K Ovine single nucleotide polymorphism array. This study included 7539 sheep from diferent locations across Australia that underwent a feld challenge with mixed gastrointestinal parasite species. Faecal samples were collected and worm egg counts for three strongyle species, i.e. Teladorsagia circumcincta, Haemonchus contortus and Trichostrongylus colubriformis were determined. Data were analysed using genome-wide association studies (GWAS) and regional heritability mapping (RHM). Results: Both RHM and GWAS detected a region on Ovis aries (OAR) chromosome 2 that was highly signifcantly associated with parasite resistance at a genome-wise false discovery rate of 5%. RHM revealed additional signifcant regions on OAR6, 18, and 24. Pathway analysis revealed 13 genes within these signifcant regions (SH3RF1, HERC2, MAP3K, CYFIP1, PTPN1, BIN1, HERC3, HERC5, HERC6, IBSP, SPP1, ISG20, and DET1), which have various roles in innate and acquired immune response mechanisms, as well as cytokine signalling. Other genes involved in haemostasis regulation and mucosal defence were also detected, which are important for protection of sheep against invading parasites. Conclusions: This study identifed signifcant genomic regions on OAR2, 6, 18, and 24 that are associated with parasite resistance in sheep. RHM was more powerful in detecting regions that afect parasite resistance than GWAS. Our results support the hypothesis that parasite resistance is a complex trait and is determined by a large number of genes with small efects, rather than by a few major genes with large efects.

Citation

Genetics Selection Evolution, v.51, p. 1-18

ISSN

1297-9686

0999-193X

Pubmed ID

31269896

Link

https://hdl.handle.net/1959.11/30814

Publisher

BioMed Central Ltd

Rights

Attribution 4.0 International

Title

Detection of genomic regions underlying resistance to gastrointestinal parasites in Australian sheep

Type of document

Journal Article

Entity Type

Publication

Author(s)	Al Kalaldeh, Mohammad Gibson, John Lee, Sang Hong Gondro, Cedric van der Werf, Julius H J
Publication Date	2019-07-03
Abstract	<b>Background:</b> This study aimed at identifying genomic regions that underlie genetic variation of worm egg count, as an indicator trait for parasite resistance in a large population of Australian sheep, which was genotyped with the highdensity 600 K Ovine single nucleotide polymorphism array. This study included 7539 sheep from diferent locations across Australia that underwent a feld challenge with mixed gastrointestinal parasite species. Faecal samples were collected and worm egg counts for three strongyle species, i.e. <i>Teladorsagia circumcincta, Haemonchus contortus</i> and <i>Trichostrongylus colubriformis</i> were determined. Data were analysed using genome-wide association studies (GWAS) and regional heritability mapping (RHM).<br/> <b>Results:</b> Both RHM and GWAS detected a region on <i>Ovis aries</i> (OAR) chromosome 2 that was highly signifcantly associated with parasite resistance at a genome-wise false discovery rate of 5%. RHM revealed additional signifcant regions on OAR6, 18, and 24. Pathway analysis revealed 13 genes within these signifcant regions (<i>SH3RF1, HERC2, MAP3K, CYFIP1, PTPN1, BIN1, HERC3, HERC5, HERC6, IBSP, SPP1, ISG20,</i> and <i>DET1</i>), which have various roles in innate and acquired immune response mechanisms, as well as cytokine signalling. Other genes involved in haemostasis regulation and mucosal defence were also detected, which are important for protection of sheep against invading parasites.<br/> <b>Conclusions:</b> This study identifed signifcant genomic regions on OAR2, 6, 18, and 24 that are associated with parasite resistance in sheep. RHM was more powerful in detecting regions that afect parasite resistance than GWAS. Our results support the hypothesis that parasite resistance is a complex trait and is determined by a large number of genes with small efects, rather than by a few major genes with large efects.
Citation	Genetics Selection Evolution, v.51, p. 1-18
ISSN	1297-9686 0999-193X
Pubmed ID	31269896
Link	https://hdl.handle.net/1959.11/30814
Publisher	BioMed Central Ltd
Rights	Attribution 4.0 International
Title	Detection of genomic regions underlying resistance to gastrointestinal parasites in Australian sheep
Type of document	Journal Article
Entity Type	Publication

Detection of genomic regions underlying resistance to gastrointestinal parasites in Australian sheep

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