The Differential Expression of Hepatic Genes Between Prelaying and Laying Geese

Abstract

Suppression subtractive hybridization was used to detect differential expression of genes in the livers of laying and prelaying geese. Liver tissues from prelaying and laying geese were dissected for mRNA extraction. The cDNA, reverse transcribed from liver mRNA of prelaying geese, was subtracted from the cDNA generated from the laying geese (forward subtraction). Five hundred seventy-six clones with possible differentially expressed gene fragments were observed by forward subtraction hybridization. After differential screening using the reverse and forward subtraction cDNA, 164 clones were subjected to gene sequence determination and further analysis. Using Northern analysis, 5 known and 8 unknown genes were shown to be highly expressed in the livers of laying geese compared with prelaying geese. Vitellogenin I, apoVLDL-II, ethanolamine kinase, G-protein gamma-5 subunit, and leucyl-tRNA synthase were highly expressed in the livers of laying geese compared with that from the prelaying geese (P<0.05). The expression of these known genes suggests that their function in the liver of laying geese is primarily involved in lipid and lipoprotein metabolism. Several of these differentially expressed genes were found to be responsive to estrogen stimulation, confirming the involvement of these genes in the egg-laying function of the goose.

Abundantly expressed hepatic genes and their differential expression in liver of prelaying and laying geese

“…In the current study, laying goose apoVLDL II mRNA was only detected in the liver, similar to our previous observation (Yen et al, 2005;Ding et al, 2007). The expression of apoVLDL II protects apoVLDL II-containing very low density lipoprotein by inhibiting the activity of lipoprotein lipase in other peripheral tissues in laying birds, thus allowing greater lipid transport to the ovary for egg yolk formation (Schneider et al, 1990).…”

“…After vitellogenin transport into oocytes, it is cleaved into 2 smaller proteins, lipovitellin and phosvitin (Byrne et al, 1989). In our previous study, we have demonstrated that vitellogenin I was highly expressed in laying goose liver (Ding et al, 2007). In the current study, we cloned the vitellogenin II genes and found that they were also specifically expressed in the liver of laying geese.…”

“…Estrogen induces the expression of lipogenic and genes related to egg formation in the liver of the layers (Kudzma et al, 1975;Dashti et al, 1983;Courtney et al, 1988). We have previously demonstrated that estrogen injection increased the expression of very low density apolipoprotein II (apoVLDL II), vitellogenin I, and G-protein-γ5 subunit in prelay geese (Ding et al, 2007). These re-sults show that the induction of genes related to egg yolk lipid generation and other aspects of lipid metabolism is required for the induction and maintenance of egg laying.…”

Selection of Reliable Reference Genes for Real-time qRT-PCR Analysis of Zi Geese (&lt;italic&gt;Anser anser domestica&lt;/italic&gt;) Gene Expression

“…Scholz chose 18S rRNA as the endogenous reference to analyze the sex-dependent gene expression level in early brain development of chicken embryos by Real-time PCR (Scholz1 et al, 2006). Yen used ACTB as a reference gene for normalization of data in transcript analysis of pituitary gland genes in laying geese (Ding et al, 2007). Chen used ACTB as a reference gene to analyze relative mRNA expression levels in the hypothalamus/pituitary glands in the Red-feather Taiwan country chicken which show significantly different reproductive performance (Chen et al, 2007).…”

“…Chen used ACTB as a reference gene to analyze relative mRNA expression levels in the hypothalamus/pituitary glands in the Red-feather Taiwan country chicken which show significantly different reproductive performance (Chen et al, 2007). Ding chose 18S rRNA as a reference gene for normalization of data in transcriptional analysis of Vitellogenin I, apoVLDL-II, ethanolamine kinase, G-protein gamma-5 subunit, and leucyl-tRNA synthase expression level in the livers of the laying and pre-laying geese (Ding et al, 2007). …”