Association of the estrogen receptor gene Pvu II restriction polymorphism with expected progeny differences for reproductive and performance traits in swine herds in Brazil

Bárbara Amélia Aparecida Santana,Mauricio Borges,Fernando H Biase,Luiz Ricardo Goulart,Robson Carlos Antunes,Mauricio Machaim Franco

doi:10.1590/s1415-47572006000200013

Bárbara Amélia Aparecida Santana, Mauricio Borges + Show 4 more

Open Access

https://doi.org/10.1590/s1415-47572006000200013

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Abstract

Estrogen has an important function in swine reproduction and growth. A Pvu II restriction enzyme polymorphism has been proven to be an important genetic variation in the estrogen receptor gene (ESR) and may be considered as a candidate gene for use in pig production but there is no data regarding the prevalence of this polymorphism in the Brazilian pig population. We used DNA samples from the following three purebred pig breeds: Large White (336 females and 26 males), Landrace (304 females and 27 males) and Pietrain (125 females and 11 males). The ESR genotyping was performed using PCR-RFLP. For each breed, genotypes for the ESR gene were compared independently for expected progeny differences (EPD) in litter size (LS), average daily weight gain (DWG) (g/day) and back fat thickness (BT) as measured in mm by ultrasound. In the Large White breed, but not the other breeds, the ESR genotype was significantly (p < 0.05) associated to LS, DWG and BT. Large Whites genotyped as AA or AB had higher EPD values for the LS and BT traits compared to BB Large Whites, while AA Large Whites had higher DWG EPD values than BB Large Whites. Our results for the Large White population showed that the A allele has a beneficial effect on LS, DWG and BT expected progeny differences.

Highlights

Reproduction is an important area that influences swine production performance, but has low heritability (0.1-0.3) for reproductive characteristics (Holm et al, 2004; Rydhmer, 2000)
Landrace pigs genotyped as BB had higher expected progeny differences (EPD) values than AA or AB animals for the litter size (LS), daily weight gain (DWG) and back fat thickness (BT) traits, the differences were not statistically significant (p > 0.05)
Animals genotyped as AA or AB had higher EPD values compared to the BB animals for LS and BT traits, and AA

Summary

Introduction

Reproduction is an important area that influences swine production performance, but has low heritability (0.1-0.3) for reproductive characteristics (Holm et al, 2004; Rydhmer, 2000) This hampers direct selection of reproductive characteristics by conventional selection mating and this means that selection for litter size in pigs has variable results (Bolet et al, 1989). Rothschild et al (1991) identified a Pvu II restriction enzyme polymorphism in the estrogen receptor gene in three families of Chinese breeds (Meishan, Fengjing and Minzhu) This polymorphism was associated to reproductive and performance traits in Meishan, Large White and Yorkshire breeds (Rothschild et al, 1996; Short et al, 1997). The polymorphism has been proven to be an important genetic variation in the estrogen receptor gene to be studied as a candidate gene for pig production, there is no data on the prevalence of this polymorphism in the Brazilian pig population

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