Expression of Eleven Egg Performance-associated Genes in the Ovary of Zi Geese <i>Anser anser domestica</i>

Abstract

a These authors contributed equallyThe relative expression of eleven egg performance-associated genes including the tau-crystallin/α enolase (ENO1), ribosomal protein S27a (RPS27A), calmodulin 1 (CALM1), solute carrier family 25 A6 (SLC25A6), arylsulfatase A (ARSA), syndecan 2 (SDC2), ribosomal protein L10a (RPL10A), ornithine decarboxylase antizyme 1 (OAZ1), cytochrome c somatic variant 2 (CYCS), adenosine triphosphate synthase, H + transporting, α subunit, isoform 1 (ATP5A1) and the ring finger protein 130 (RNF130) in the ovaries of pre-laying and laying Zi geese were analyzed using quantitative real-time PCR (qRT-PCR). Comparison between pre-laying and egg-laying stages, the relative expression of ENO1, RPS27A, SLC25A6, ARSA, SDC2, RPL10A, OAZ1, CYCS and RNF130 were significantly upregulated (P＜0.05), whereas the CALM1 and ATP5A1 were highly significantly up-regulated (P＜0.01). This study established the primary foundation to understand the possible roles of these genes in the ovaries.Key words: egg performance-associated genes, geese, ovaries, qRT-PCR J. Poult. Sci., 50: 91-98, 2013 Introduction Zi geese (Anser anser domestica) are excellent layers (around 100 per year) with a superior feed-to-egg conversion ratio (Kang et al., 2009). This species breeds in Northeast China (HeiLongjiang and JiLin provinces). In our previous study, in order to study the molecular genetic mechanisms of egg laying and improve laying performance, suppression subtractive hybridization (SSH) and reverse dot-blot were employed to identify egg laying performance-associated genes in the ovaries. We have discovered that the expression of 18 known and 8 unknown gene fragments were higher in the ovaries of egg-laying geese than pre-laying geese (Kang et al., 2009 identified to be differentially expressed in the ovaries by SSH. Their expression were confirmed by using quantitative real-time PCR (qRT-PCR) in both egg-laying and pre-laying stages in the ovaries of the Zi geese. This results provided the primary foundation to understand the possible roles of these genes in egg formation in geese. Materials and Methods Geese and Tissue CollectionTwenty female Zi geese were selected on a local farm and were raised according to the program used in farm. All the geese were fed according to conventional farming (Kang et al., 2009). Ten geese were killed by exsanguination at 5-month-old (average BW＝3.0±0.2 kg) and the ovaries were treated at pre-laying stage. Another 10 geese were killed at 8-month-old (average BW＝3.5±0.2 kg) and the ovaries were treated at egg-laying stage. Ovaries samples, which comprised the whole ovary including the small and large yellow follicles, were rapidly removed, wrapped in foil, frozen in liquid nitrogen, and stored at −70℃ until analysis. Extraction of Total RNA and Quality ControlTotal RNA was prepared by the Trizol reagent (Invitrogen Corporation, CA, U.S.A.) according to the instructions of the manufacturer. The total RNA samples from pre-laying and laying ovaries (n＝10, for each) were pooled separately. Genom...