Four single nucleotide polymorphisms (SNPs) are associated with resistance and resilience to Haemonchus contortus in Brazilian Morada Nova sheep

Autor(es)

Haehling, Marei B. ^[1] ; Cruvinel, Giovanna G. ^[2] ; Toscano, Joao H. B. ^[1] ; Giraldelo, Luciana A. ^[2] ; Santos, Isabella B. ^[1] ; Esteves, Sergio N. ^[3] ; Benavides, V, Magda ; Barioni Junior, Waldomiro ^[3] ; Niciura, Simone C. M. ^[3] ; Chagas, Ana Carolina S. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Fac Ciencias Agr & Vet, UNESP, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP - Brazil

^[2] Ctr Univ Cent Paulista UNICEP, Rua Miguel Petroni 5111, BR-13563470 Sao Carlos, SP - Brazil

^[3] Embrapa Pecuaria Sudeste, Rod Washington Luiz, Km 234 Fazenda Canchim, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Veterinary Parasitology; v. 279, MAR 2020.
• Citações Web of Science: 0

Resumo

Gastrointestinal nematodes are a major constraint in sheep production. Breeding for resistance has proven to be an effective and feasible approach to address this problem. The use and investigation of genetic markers for resistance traits could accelerate genetic progress and lead to a better understanding of underlying molecular mechanisms. Thus, the aim of this study was to evaluate if five single nucleotide polymorphisms SNPs OAR2\_14765360, OAR6\_81718546, OAR11\_62887032, OAR12\_69606944 and OAR15\_59871543 are associated with resistance and resilience traits in a flock of the Morada Nova sheep breed. Lambs were submitted to two consecutive parasite challenges by oral infection with 4000 infective larvae L-3) of Haemonchus contortus. Fecal egg counts (FEC), packed cell volume (PVC) and body weight were measured every one or two weeks for 42 days in each trial. DNA samples from 287 lambs, 131 ewes and 4 rams were amplified by ARMS-PCR or PCR-RFLP and genotypes were determined. Analysis of variance (ANOVA) was used for association analyses between genotypes and phenotypes. In case of significant association, the allele substitution effect was calculated based on a linear model. OAR2\_14765360 and OAR12\_69606944 were associated with FEC, and OAR12\_69606944 also had significant effects on PCV and weight gain, showing favourable associations of the CC genotype with all evaluated traits. Both OAR6\_81718546 and OAR11\_62887032 were associated with weight gain, and OAR6\_81718546 had an additional effect on PCV. OAR15\_59871543 was not polymorphic in the population. OAR6\_81718546 and OAR12\_69606944 presented significant allele substitution effects of -1.06 +/- 0.52 kg for the T allele on final body weight and 0.74 +/- 0.32 for the C allele in PCV of the same sampling date, respectively. This is the first report of SNPs associated with gastrointestinal nematode resistance in this sheep breed. Our findings support the existence of quantitatice trait loci (QTL) for resistance and resilience in linkage disequilibrium with the polymorphic SNPs and suggest their future use for explorations of these traits in Morada Nova sheep. (AU)

• Processo FAPESP: 17/24289-0 - Cordeiros Morada Nova: cuidados ao nascimento, avaliação dos níveis de infecção por nematóides gastrintestinais e seu impacto no ganho de peso
• Beneficiário: Luciana Aparecida Giraldelo
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 17/01626-1 - Caracterização genética e de respostas imunes associadas ao fenótipo de resistência parasitária em rebanho ovino da raça Morada Nova
• Beneficiário: Ana Carolina de Souza Chagas
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/00373-2 - Caracterização de respostas imunes locais associadas ao fenótipo de resistência parasitária em cordeiros da raça morada nova
• Beneficiário: João Henrique Barbosa Toscano
• Modalidade de apoio: Bolsas no Brasil - Mestrado