Correlation between Beta-Globin genotyping and eggs count per gram of faeces (EPG) in sheep of different genetic groups.

• Grant number: 25/05023-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Biological Sciences - Parasitology - Helminthology of Parasites
• Principal Investigator: César Cristiano Bassetto
• Grantee: Heloisa Bravim Murback
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Sheep farming is constantly growing in Brazil; however, its production suffers from losses caused by gastrointestinal nematodes, mainly by the species Haemonchus contortus. The excessive use of anthelmintics to control these parasites has led to severe anthelmintic resistance. In search of alternatives for controlling gastrointestinal nematodes, genetic selection has been the focus of many studies. This study aims to genotype different genetic groups of sheep to identify the different beta-globin haplotypes (AA, AB, or BB) and correlate them with egg counts per gram of feces (EPG). Using abomasum or blood samples stored from previously conducted experiments, DNA extraction will be performed using the "QIAamp DNA Micro Kit." DNA amplification will be carried out using conventional multiplex PCR, employing the "Taq DNA Polymerase 2X Master Mix RED kit" and specific primers. After thermal cycling, the amplified product will be subjected to agarose gel electrophoresis. The EPG count data will be obtained from laboratory records, and an individual cumulative EPG will be calculated to determine resistance profiles (Resistant - high EPG, or Susceptible - low EPG). The genotyping data obtained through PCR and the EPG count data will be analyzed using the Kappa concordance coefficient. By evaluating different genetic groups and sheep breeds, this study aims to validate beta-globin genotyping as a new tool to assist producers in selecting sheep that are resistant or susceptible to gastrointestinal nematodes.