Genetic Stability, Inheritance Patterns and Expression Stability in Biotech Crops

Abstract

Demonstration of the stability of traits newly introduced into a plant genome via genetic engineering approaches comprise a significant portion of the safety assessment that these products undergo prior to receiving the requisite regulatory approvals enabling commercial authorization. Different regions of the world have different regulatory requirements and many ask similar questions from multiple and overlapping perspectives. The entire central dogma, that is stability at the DNA level, mRNA level and protein level, is assessed for each product, although only a few regulatory authorities request data at the mRNA level. In this article, we present inheritance data obtained during the safety assessment of biotech products representing specific transgenic events in several crop species including Brassica napus (canola); canola quality Brassica juncea (yellow seeded canola); Glycine max (soybean), and Gossypium hirsutum (cotton) in which different traits have been introduced. The data presented confirm that all events examined were nuclear insertions that resulted in typical Mendelian Inheritance patterns and that the proteins are expressed similarly across multiple generations regardless of whether they were from backcrossed or outcrossed generations. These results demonstrate that newly inserted genes are transmitted to their progeny in a stable manner similar to that of endogenous genes. Further, the findings demonstrate that assessments of multigenerational stability have very limited value to a safety assessment.

Applying knowledge and experience from potato (Solanum tuberosum) to update genetic stability data requirements in the risk assessment for vegetatively propagated biotech crops

“…Conventional breeding practices that rely on sexual reproduction contribute to the maintenance of genetic heterozygosity within crop populations where meiosis and gamete fertilization have the potential to alter the chromosomal makeup of the cell during segregation and recombination. However, even for row crops developed using biotechnology and propagated by seed, newly inserted genes have been shown to be inherited in a stable and consistent manner similar to endogenous genes, across multiple generations ( Privalle et al, 2020 ).…”

“…Plants developed using biotechnology are not necessarily less stable than plants developed through conventional breeding, or even than wild relatives ( Privalle et al, 2020 ). While molecular characterization of the inserted DNA is important for food safety assessments, genetic stability data should only be required when there is an identified pathway to harm.…”

Comparison of RF3 <i>B. juncea</i> to RF3 <i>B. napus</i>

“…[39]. The mean, standard deviation, and range of analyte concentrations in RF3 B. juncea and RF3 B. napus are presented PAT/bar and Barstar in Table8 and Table 9, respectively.…”