Sequential gene activation and gene imprinting during early embryo development in maize

Area of Science:

• Epigenetics
• Plant Developmental Biology
• Genomics

Background:

• Gene imprinting is a known epigenetic phenomenon in maize endosperm.
• Its occurrence in maize embryos has been a subject of scientific debate.

Purpose of the Study:

• To investigate the presence and extent of gene imprinting in maize embryos.
• To analyze allelic gene expression patterns during early maize embryo development.

Main Methods:

• Utilized high-throughput RNA sequencing on laser capture microdissected and manually dissected maize embryos.
• Analyzed embryos from reciprocal crosses (B73 x Mo17) across six developmental time points (3-13 days after pollination).
• Performed co-expression analysis and in situ hybridization.

Main Results:

• Confirmed gene imprinting in maize embryos, with more imprinted genes detected at earlier developmental stages.
• Identified 64 strongly imprinted genes in manually dissected embryos (5-13 DAP) and 41 in laser capture microdissected embryos (3-5 DAP).
• Discovered 36 novel imprinted genes, not previously identified in maize endosperm or embryos.

Conclusions:

• Gene imprinting is a significant epigenetic mechanism occurring in maize embryos.
• This study provides strong evidence for gene imprinting in maize embryos, contributing to understanding early embryonic development.