Validation of a reference gene (BdFIM) for quantifying transgene copy numbers in Brachypodium distachyon by real-time PCR.
Brachypodium distachyon has been proposed as a new model system for gramineous plants with a sequenced genome and an efficient transformation system. Many transgenic B. distachyon plants have been generated in recent years. To develop a reliable fast method for detecting transgenic B. distachyon and quantifying its transgene copy numbers, a species-specific reference gene is of great priority to be validated both in qualitative PCR and quantitative real-time PCR detection. In this study, we first proved that the BdFIM (B. distachyon fimbrin-like protein) gene is a suitable reference gene in qualitative PCR and quantitative real-time PCR for B. distachyon. Fourteen different B. distachyon varieties were tested by both qualitative and quantitative PCRs, and identical amplification products of BdFIM were obtained with all of them, while no amplification products were observed with samples from 14 other plant species, suggesting that BdFIM gene was specific to B. distachyon. The results of Southern blot analysis revealed that the BdFIM gene was low copy number in seven tested B. distachyon varieties. In conclusion, the BdFIM gene can be used as a reference gene, since it had species specificity, low heterogeneity, and low copy number among the tested B. distachyon varieties. Furthermore, the copy number of inserted sequences from transgenic B. distachyon obtained by real-time PCR methods and Southern blot confirmed that the BdFIM gene was an applicable reference gene in B. distachyon.
Shanghai Chenshan Plant Science Research Center, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai Chenshan Botanic Garden, 3888 Chenhua Road, Songjiang, Shanghai, China, 201602.
Hong
H
Zhu
Feng
F
Wen
Peng
P
Li
Xiang
X
Liu
Jianmei
J
Cao
Min
M
Jiang
Feng
F
Ming
Zhaoqing
Z
Chu
D001483:Base Sequence; D015139:Blotting, Southern / Q000592:standards; D058431:Brachypodium / Q000235:genetics*; D018628:Gene Dosage; D018506:Gene Expression Regulation, Plant; D020043:Genes, Essential; D018745:Genome, Plant; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D060888:Real-Time Polymerase Chain Reaction / Q000592:standards; D012015:Reference Standards; D019076:Transgenes