To understand the relationship between DNA replication and developmental programmes, it is important to examine replication and nuclear substructure in different developmental contexts including natural cell-cycle progressions in situ. Plant meristems offer an ideal opportunity to analyse such processes in the context of normal growth of an organism. Our current understanding of large-scale chromosomal DNA replication has been limited by the lack of appropriate tools to visualize DNA replication with high resolution at defined points within S phase. In this perspective, we discuss a promising new system that can be used to visualize DNA replication in isolated maize (Zea mays L.) root tip nuclei after in planta pulse labelling with the thymidine analogue, 5-ethynyl-2′-deoxyuridine (EdU). Mixed populations of EdU-labelled nuclei are then separated by flow cytometry into sequential stages of S phase and examined directly using 3-dimensional deconvolution microscopy to characterize spatial patterns of plant DNA replication. Combining spatiotemporal analyses with studies of replication and epigenetic inheritance at the molecular level enables an integrated experimental approach to problems of mitotic inheritance and cellular differentiation.

Genome size variation in wild and cultivated maize along altitudinal gradients

Concepción M. Díez,1 Brandon S. Gaut,1 Esteban Meca,2 Enrique Scheinvar,3 Salvador Montes-Hernandez,4 Luis E. Eguiarte,3 and Maud I. Tenaillon5

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119021/

Thank you, Desimir Knezevic. I am reading the paper, but the genome  size of Zea mays 'B73' as the second internal control used in this paper was 5.64 pg/2C(which means genome size= 2.82pg). Which also conflict with previous result( neither FCM nor whole genome sequence size).

Now, I got really confused about which size I should use in my experiment.

Thank you again, with my appreciation.

Thank you very much, Naveen Kumar K.L. The paper you send is quite useful, I am reading it now.

thank you, have a nice day.

From my experience you will face the same situation / problem in every species you are working with. I usually go by the Royal Botanic Gardens, Kew - Plant DNA C-values database. http://data.kew.org/cvalues/

For maize it says the following: 2.73 pg Bennett et al., 1976

With flow cytometry the result will always vary depending on what you use as a standard and how you define the standard size.

I am not familiar with your experiment - if it simply for comparison purposes the absolute genome size is not that important - as you want to detect relative differences...

Nonetheless, you will have to decide on one.

thank you, Kristina Košmrlj.