Ovine beta-globin gene: A new qPCR for rapid haplotype identification and association with susceptibility to Haemonchus contortus infection

Author(s)

Okino, Cintia Hiromi ^[1] ; Meo Niciura, Simone Cristina ^[1] ; Barbosa Toscano, Joao Henrique ^[2] ; Esteves, Sergio Novita ^[1] ; dos Santos, Isabella Barbosa ^[2] ; von Haehling, Marei Borsch ^[2] ; Figueiredo, Amanda ^[2] ; de Sena Oliveira, Marcia Cristina ^[1] ; de Souza Chagas, Ana Carolina ^[1]

Affiliation

^[1] Embrapa Pecuaria Sudeste, Rodovia Washington Luiz, Km 234 S-N, POB 339, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Estadual Paulista UNESP, Fac Ciencias Agr & Vet, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Sao Paulo - Brazil

• Document type: Journal article
• Source: Veterinary Parasitology; v. 294, JUN 2021.
• Web of Science Citations: 0

Abstract

Two beta-globin allelic haplotypes (A and B) were identified in domestic sheep, wherein animals which are homozygous for beta(B) allele (BB haplotype) have a deletion of pre-adult beta(c)-globin and consequently are less tolerant to anemia and hypoxia. Since Haemonchus contortus infection, is associated with severe anemia, studies performed from 1960s to 1990s investigated the association between beta-globin haplotype and resistance against this parasite. However, the findings were controversial, pointing out from increased resistance in animals harboring the beta(A) allele to inexistence of association. Thus, our study aimed to develop a qPCR for beta-globin haplotype identification, and to evaluate the association between beta-globin haplotype and resistance against H. contortus in a group of sheep submitted to artificial infection with this parasite. A total of 286 lambs of Morada Nova breed were experimentally challenged with 4000 H. contortus L3 and monitored for 112 days from weaning. Significantly improved (p < 0.05) phenotypic profiles (lower fecal egg counts, higher packed cell volume and birthweight) were observed for AA haplotype animals, especially when compared to BB animals, while AB animals were similar to BB. This is the first report of a qPCR assay for ovine beta-globin haplotype identification. In view of significant differences of phenotypic profiles between haplotype groups, the developed qPCR may constitute an important tool for sheep producers to improve genetic selection of parasite resistant animals. (AU)

• FAPESP's process: 19/02929-3 - Target selective treatment based on liveweight gain as nematode control strategy in Morada Nova lamb
• Grantee: Ana Carolina de Souza Chagas
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/16070-1 - Study of the impact of gastrointestinal nematodes infection on the performance of Morada Nova Lambs for development of a targeted selective treatment
• Grantee: Isabella Barbosa dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/00373-2 - Characterization of local immune responses associated with the parasitic resistance phenotype in morada nova lambs
• Grantee: João Henrique Barbosa Toscano
• Support Opportunities: Scholarships in Brazil - Master