The Expression of Genes Related to Egg Production in the Liver of Taiwan Country Chickens

Abstract

The purpose of this study was to detect expression of genes related to egg production in Taiwan Country chickens by suppression subtractive hybridization. Liver samples of mRNA extraction from two Taiwan Country chicken strains (L2 and B), originated from the same population but with very distinct egg production rates after long-term selection for egg and meat production respectively. Two-way subtraction was performed. The hepatic cDNA from the low egg production chickens (B) was subtracted from the hepatic cDNA from the high egg production strain (L2). The reversed subtraction (L2 from B) was also performed. The resulting differentially expressed gene fragments were cloned and sequenced. We sequenced 288 clones from the forward subtraction and 96 clones from the reverse subtraction. These genes were subjected to further screening to confirm the differential expression between the two genetic breeds of chickens. The apolipoprotein B (apoB) was expressed to a greater extent in the liver of the L2 than in the B line chickens. The 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (PURH) was expressed to a greater extent in the liver of the B than in the L2 strain chickens. We demonstrated that both apoB and PURH were more highly expressed in the liver than that in other tissues (muscle, ovary, and oviduct) in laying Taiwan Country chickens. Taken together, these data suggest that after the selection for egg production, expression of apoB and PURH genes were also changed. Whether the changed expression of these genes is directly related to egg production is not known, but these two genes may be useful markers for egg laying performance in Taiwan Country chickens.

Transcriptome analysis reveals differentially expressed genes associated with high rates of egg production in chicken hypothalamic-pituitary-ovarian axis

“…In this process, the hypothalamus produces gonadotropin-releasing hormone-I (GnRH-I) which triggers pituitary gland (adenohypophysis) to release FSH and LH, and stimulates the secretion of estradiol (E2) and progesterone (P4) in ovary while ovulation 19 . Hitherto, several studies have focused to uncover the molecular mechanism associated with egg production performance in chicken 10,20,21 . However, the differential gene expression and key pathways mediating the egg production process across hypothalamic-pituitary-ovarian (HPO) axis are yet to be uncovered.…”

Associations of Single Nucleotide Polymorphisms in BMPR-IB Gene with Egg Production in a Synthetic Broiler Line

“…Choi et al (2006) identified two SNPs in the uncoupling protein gene which are associated with daily percent lay. Ding et al (2008) showed that the expression of apoB and PURH genes in liver changed after selection for egg production. In order to identify more DNA markers that are associated with egg production in chickens, the present study selected chicken BMPR-IB as a candidate gene to characterize its polymorphisms and analyze their associations with egg production.…”

Canonical Correlation Analysis for Estimation of Relationships between Sexual Maturity and Egg Production Traits upon Availability of Nutrients in Pullets

“…Management and feeding practices in the starter, grower and/or developer phases can alter the body weight gain, growth curve, early egg weight and sexual maturity of the pullets and consequently egg production. Furthermore, advances in genetic selection make today's pullets quite different from those of only a few years ago (Flock, 1998;Jackson, 2006;Ding et al, 2008). Therefore, information on feeding programs for egg-type pullets to point of lay is still required to today's or improved pullets achieve an adequate sexual maturity in terms of body size at first egg, weight of the first egg and days to first egg, and subsequently the production characteristics of laying hens (Zhong et al, 2007;Sungu, 2007).…”