Digital gene expression analysis of mature seeds of transgenic maize overexpressingAspergillus nigerphyA2and its non-transgenic counterpart

Abstract

The next generation sequencing technologies have been recently used for transcriptome analysis in many organisms because of the decreased sequencing cost and increased sequence output. In this study, we used digital gene expression (DGE) technique to compare the transcriptomic changes in mature seeds between transgenic maize overexpressing Aspergillus niger phyA2 and its non-transgenic counterpart. Deep sequencing of DGE libraries of the transgenic and its non-transgenic counterpart seeds generated 3,783,500 and 3,790,500 reads of 21-nucleotide, respectively, with frequencies spanning over four orders of magnitude. In transgenic maize, 53.97% of the unambiguous signature tags were mapped to the maize B73 reference genome, and 46.47% of genes were detected by at least two reads; in non-transgenic maize, the corresponding numbers were 51.38% and 47.39%. Compared with non-transgenic counterpart, about 12% of detected genes were differentially expressed in the transcriptome of transgenic maize seeds. Among these differentially expressed genes, there were 23 transcription factors in 14 families and no allergen genes. Pathway enrichment analysis revealed that 21 pathways were significantly affected by the transgenic event, in which the pathway involved in protein processing in endoplasmic reticulum was the most significantly affected. Results from this study indicated that both intended and unintended transcriptomic changes occurred in the transgenic maize, thus emphasizing the importance of transcriptome profiling in risk assessment of transgenic events.

Fungal Phytase Production in Different Hosts: A Brief Review

“…Other types of plants have also been addressed for the expression of heterologous phytase. Plants such as Triticum aestivum, Chlamydomonas reinhardtii, Mature maize, Brassica napus and Zea mays L were used to express A. japonicas phytases reported by Abid, et al (2017) and A. niger studied by Rao, et al (2016), Rao J, et al (2013), and Drakakaki, et al (2005) [33][34][35][36][37] respectively.…”

Transgenic cereals: Current status and future prospects

“…There is great deal of published information on these topics (eg http://www.efsa.europa.eu/en/panels/gmo.htm) and it will not be repeated here, but some of the recent information on compositional analysis has been summarised by Herman and Price (2013), Kitta (2013) and Privalle et al (2013). Other specific recent data include information on transcriptome changes in maize expressing a phytase gene (Rao et al, 2013), tests for possible changes in allergens in GM maize (Fonseca et al, 2012) and a proteomic study on GM rice (Gong et al, 2102). Animal feeding tests (Buzoianu et al, 2013) are also a required part of any regulatory process, though the outcome of some such tests has recently provoked further controversy about GM safety (Arjó et al, 2013;Fresco, 2013) .…”