Identification of a dosage-dependent region on chromosome 10 in maize which alters lipid composition in maize embryos

We wish to report the possible identification of another dosage dependent factor affecting the fatty acid composition of embryos. Altering the dosage of the long arm of chromosome 10 using TB-10L(19) reveals differences between hyperploid and hypoploid embryos for both palmitic and stearic acids. The data in the table below (% ± standard error) show that hyperploid embryos have a significantly higher percentage of palmitic acid and a significantly lower percentage of stearic acid than their hypoploid siblings:

H75 310 x 103-6 TB-10L(19)
# C16:0 C18:0 C18:1 C18:2
20 (6) 12.44±0.52 2.55±0.12 25.61±0.99 59.04±1.15
22 (7) 16.29±0.72* 1.94±0.15*** 25.34±0.68 56.11±0.58
*Significantly different from the hypoploid at p = 0.05.
***Significantly different from the hypoploid at p = 0.001.

TB-10L(19) with the breakpoint close to the centromere is one of a series of B-10 translocations generated by Bor-yaw Lin whose breakpoints lie throughout the entire length of 10L. This series can be used to further locate the dosage dependent factor discovered to specific chromosome regions between the individual breakpoints.

J. D. Shadley and D. F. Weber

Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.

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