Effect of luteinizing hormone/choriogonadotropin receptor (LHCGR) gene on chicken reproductive traits

Abstract

Luteinizing hormone/choriogonadotropin receptor (LHCGR) gene, potentially related to reproductive traits in chickens, was genotyped by using the Pooled DNA Sequencing, PCR-SSCP and Directing Sequencing techniques. 306 Erlang Mountain chickens form one line (SD03, a line that has been selected for egg quality from a local chicken breed in Sichuan province, China) were genotyped in this study. The associations between LHCGR polymorphisms and six reproductive traits [body weight at first egg (BWAFE), weight of first egg, age at first egg (AFE), number of eggs at 300 days of age (EN), body weight at 300 days of age and egg weight at 300 days of age (EWTA)] were estimated using the one-way analysis of variance method. Results showed that SNP +G4058A and SNP +T4099G of the LHCGR gene were significantly associated with BWFE and AFE. Birds with the AG genotype for the +G4058A SNP exhibited shorter AFE (P < 0.05) and greater EN than those of the GG and AA genotypes, suggesting a balancing selection (overdominance); the effect of allele C in SNP +C3021T and allele C in SNP +T4490C on EN and AFE is additive and may reflect the influence of positive selection. These alleles have promise as genetic markers for future marker-assisted selection.

Polymorphisms in the Chicken Growth Differentiation Factor 9 Gene Associated with Reproductive Traits

“…Birds were reared in the poultry farm of Sichuan Agricultural University (Sichuan, China), and feed protocols and conditions followed those in previous research [ 33 ]. Six reproductive traits that are conventional selection indices in breeding programs for laying hens [ 3 , 16 , 34 ] were measured: age at first egg (AFE), body weight at first egg (BWFE), weight of first egg (WFE), body weight at 300 days of age (BWTA), egg weight at 300 days of age (EWTA), and total number of eggs at 300 days of age (EN). Blood samples were collected from the wing veins of all chickens.…”

Influence of the digestive/reproductive tract microbiota on chicken egg production beyond host genetics

“…Egg production is an important economic trait in the poultry industry [9], and it is a polygenic inheritance trait with low to moderate heritability values ranging from 0.05 to 0.44, depending on the period involved [10,11]. Therefore, other effective approaches for modulating egg production in laying hens are urgently required.…”