--J. W. Higginbotham

Restriction fragment length polymorphism (RFLP) data exist for 35 of 37 inbred lines used to construct a two-dimensional (2-D) electrophoresis dataset of seedling proteins. An introduction to the 2-D dataset appears above (Higginbotham, JJW et al., this Newsletter) and in Higginbotham et al. (Electrophoresis, in press).

Genes conditioning the expression of protein spots are being assigned to putative chromosome locations by correlating protein spots with restriction fragments. The probe library in use at Pioneer Hi-Bred was constructed from genomic DNA. A few probes are known to contain transcription regions, but the vast majority of them are anonymous pieces of DNA. By linking the 2-D protein profile data to the RFLP data, information on sites of active gene expression will be acquired. Furthermore, protein spots which appear to be associated with fragments known to be linked to quantitative trait loci (QTLs) may merit further scrutiny.

Table 1 lists seven putatively allelic pairs of proteins and three other proteins. The putative locations of the genes conditioning the expression of these proteins are shown along with the probes on that chromosome arm which were correlated with the proteins. Many of these probes are genetically linked to a number of QTLs which are given in Table 1.

Because this is a correlative study rather than a mapping project, the power of the analysis is limited. It is, however, a method of ascertaining probable sites of active gene expression in the absence of a cDNA linkage map. Proteins visualized on 2-D gels may, themselves, be used as markers especially when the segment is poorly marked. The short arm of chromosome 9 is such a segment.

Table 1.  Protein spots, RFLP probes, and quantitative traits which appear to be associated.  The chromosome arm locations of the RFLP probes are given.
 

Protein Spot #	Chromosome Arm	Probe ID	Quantitative Trait
4204 4205	1S	PIO200689 PIO200603 UMC094 PIO200640	Heat units to pollen shed Delay between shed and silk  % moisture at harvest
8835	1L	UMC128 UMC033 PIO200668
	8L	UMC089 UMC030 UMC007	Heat units to pollen shed Heat units to silk
112 144	1L	PIO200557 UMC084
318 401	2	UMC139 PIO200005 UMC034 BNL06.20	% moisture at harvest Stay green
3806 4808	3L	PIO200509 PIO200576 PIO200558
311 312	4L	BNL07.65 PIO200071 BNL10.05 UMC019 UMC066	Ear height
5405 5406	5L	UMC040 PIO150018 PIO150024 PIO200589 PIO200715	Test weight Cob diameter Ear diameter Row length Row number
224	7L	PIO200593 BNL08.39 BNL08.32 PIO200684 PIO200708 PIO200746	Ear height Stay green % moisture at harvest
301	9S	UMC109 PIO100005 PIO200052 UMC081	Row number Yield in bushels per acre 100 kernel weight Plant height Heat units to pollen shed Heat units to silk
3804 3808	10L	BNL10.13 UMC044A

Return to the MNL 65 On-Line Index
Return to the Maize Newsletter Index
Return to the MaizeGDB Homepage