Artículos de revistas
Reference gene selection for gene expression analysis of oocytes collected from dairy cattle and buffaloes during winter and summer
Fecha
2014-03Registro en:
PLOS ONE, São Francisco, v. 9, n. 3, e93287, p. 1-13, March 2014
10.1371/journal.pone.0093287
Autor
Macabelli, Carolina Habermann
Ferreira, Roberta Machado
Gimenes, Lindsay Unno
Carvalho, Nelcio Antonio Tonizza de
Soares, Júlia Gleyci
Ayres, Henderson
Ferraz, Márcio Leão
Watanabe, Yeda Fumie
Watanabe, Osnir Yoshime
Sangalli, Juliano Rodrigues
Smith, Lawrence Charles
Baruselli, Pietro Sampaio
Meirelles, Flavio Vieira
Chiaratti, Marcos Roberto
Institución
Resumen
Oocytes from dairy cattle and buffaloes have severely compromised developmental competence during summer. While analysis of gene expression is a powerful technique for understanding the factors affecting developmental hindrance in oocytes, analysis by real-time reverse transcription PCR (RT-PCR) relies on the correct normalization by reference genes showing stable expression. Furthermore, several studies have found that genes commonly used as reference standards do not behave as expected depending on cell type and experimental design. Hence, it is recommended to evaluate expression stability of candidate reference genes for a specific experimental condition before employing them as internal controls. In acknowledgment of the importance of seasonal effects on oocyte gene expression, the aim of this study was to evaluate the stability of expression levels of ten well-known reference genes (ACTB, GAPDH, GUSB, HIST1H2AG, HPRT1, PPIA, RPL15, SDHA, TBP and YWHAZ) using oocytes collected from different categories of dairy cattle and buffaloes during winter and summer. A normalization factor was provided for cattle (RPL15, PPIA and GUSB) and buffaloes (YWHAZ, GUSB and GAPDH) based on the expression of the three most stable reference genes in each species. Normalization of non-reference target genes by these reference genes was shown to be considerably different from normalization by less stable reference genes, further highlighting the need for careful selection of internal controls. Therefore, due to the high variability of reference genes among experimental groups, we conclude that data normalized by internal controls can be misleading and should be compared to not normalized data or to data normalized by an external control in order to better interpret the biological relevance of gene expression analysis.