maize mutant phenotypes

Ds-Cbreaker Clf1; (Ds-1S3-Clf1) Ear showing Ds-1S3 original kernel. Section of a fully colored M1 ear from the cross of Clf1/clf1 x Ac Clf1/- Clf1, Ds-10L2 R1-sc/Ds-10L2 R1-sc showing a single kernel with many tiny to small colorless patches, indicating chimeral loss of Clf1 in the 3N clf1 clf1 Clf1 endosperm, among fully normal colored sibling clf1 kernels. The embryo of this kernel was expected to be Ac Clf1/- clf1 with an associated Ds breaker nearby. The single purple and colorless mosaic kernel with small to medium-sized colorless sectors on a full purple ear was designated as Ds-1S3.

Ds-Cbreaker Clf1; (Ds-1S3-Clf1) Ds-1S3 kernels on the ear from the self of Ac Ds-1S3 Clf1/clf1, Ds-10L2 R1-sc/Ds-10L2 R1-sc plant showing many small to medium losses of Clf1 function caused by a distal chromosome breaking Ds. The diluted appearance of the middle kernel is the result of one dose of R1-sc in the 3N aleurone. This image shows normal full-colored kernels (1 and 3) and kernel 4 is a colorless floury defective kernel overlaid by red streaks of P1-vv in the pericarp.

Ds-Cbreaker Clf1; (Ds-1S3-Clf1) Enlargement of the middle kernel from Image 2 above, showing loss of color as small as two cells in size, and also a few cases of intense few-celled dots that may be interpreted as twin spots, but are not definitive because the dilution is the result of function of one dose of the R1 locus. Their small size and rarity makes this case subject to other interpretations. This case is similar to kernel 3.

Ds-Cbreaker Clf1; (Ds-1S3-Clf1) The top first and third kernels are heterozygous (Ac Ds Clf1/clf1/clf1 aleurone) and have large frequent losses of one dose of Clf1. The top middle kernel (#2) is probably the reverse combination, having two doses of Ac Ds Cld1/Ac Ds Clf1/clf1 and shows colorless spots only where the loss of both Deks coincide. The dark spots arise when twin spots from the breakage-fusion-bridge cycle occur, causing an increase in the copy number of clf1s that show on this coincidentally dilute kernel. This lighter occurrence establishes that Ds1-S3 is located distal to the centromere. In this case, Ac, Clf1 and Ds are all on the same chromosome strand and linked together, so there is one dose of all three of these in the pollen grain and two doses of all of these in the female gamete. The colorless kernel at the bottom lower left (#4) is homozygous clf1. The rounded kernel on the lower right side (#5) is lighter in color and has fewer colorless spots, and a few dark spots. The background is mottled. This kernel shows an interesting effect in that the upper right hand side of the kernel matches kernel #3 just above it, but the lower side matches kernel #2 to the left. This occurs because kernel #5 has two doses of Ds like the middle kernel (#2) so most of kernel 5 is like kernel #2, and a colorless patch arises only when the two of them coincide. In the upper right hand corner of kernel #5, an early event caused one of the two Ds cases to be lost which made the Ds disappear in the whole area. After the loss event, all subsequent tissue will not be colorless, it will be colored with the same kind of spotting as kernels #1 and #3 which have only one dose of Clf1 Ds.

Ds-Cbreaker Clf1; (Ds-1S3-Clf1) An enlarged view of kernel #3 from image above, showing colorless spots as small as one cell, indicating loss as late as the last cell division of the aleurone. The appearance of scattered one- to six-cell dark dots, especially along the border of the larger colorless spots, suggests twin spots but this is not definitive on such an intense background color. The fact that Ac is on the same chromosome but distal to Ds makes the interpretation of this observation difficult.