Glu-D1bn{03124}. 5*t+12{03124}. dv: Ae. tauschii.
Glu-D1 {421} appears to have arison as the result of a deficiency of subunit 12 from Glu-D1a (2+12); subunits 2 and 12 are referred to as D1 and D5 in {421}. One of the Glu-D1o subunits has been numbered 13 in {755}; 13 was previously used to number a subunit encoded by Glu-B1f {13+16} and Glu-B1g {13+19} {1116}. Subunit 9 of Glu-D1g (5+9) was so numbered in {478} because its mobility is the same as one of the subunits encoded by Glu-B1c (7+9).
Five combinations involving 6 HMW subunits [1D {p-t}] are listed in {420}. Eleven additional Glu-D1 alleles in T. tauschii were described {755}.
Seven transfers of Glu-D1a and 10 of Glu-D1d (5+10) from chromosome 1D to chromosome 1A in triticale were described {846}.
The subunit 2.2* encoded by Glu-D1al above and Glu-D1-1m in the appropriate list below has an unusually high Mr comparison of its N-terminal sequence and amino acid composition with those of subunit 2 (encoded by Glu-D1-1a indicated that its greater Mr, could be due to the presence of a larger central repetitive domain, although further evidence suggested that this does not affect the conformational properties of the subunit {02107}. The alleles originally designated Glu-D1w (encoding 'subunits' 2 (or 2t denoting its origin in the Ae. tauschii genome) +T1+T2), Glu-D1af (encoding 3 9or 3t)+T1+T2) and Glu-D1ag (encoding 1.5 (or1.5t)+T1+T2) share the component T1 that was originally classified as a HMW glutenin. However, it has since been shown {02108} that this protein is soluble in aqueous ethanol, casting doubt upon this classification. More recently, it has been shown {02109}, from one and two dimensional gel electrophoresis based upon SDS-PAGE and A-PAGE, and from N-terminal sequencing, that this protein is an omega-gliadin of unusually low electrophoretic mobility in SDS-PAGE, encoded by a locus located on the short arm of chromosome 1D, though distant 913.18cM) from the principle gliadin-encoding locus on 1D, Gli-D1, and 40.20cM from the high molecular weight encoding locus, Glu-D1. The authors named the locus Gli-DT1 (see below, section Gliadins). Reference to T1 was consequently removed from the Glu-D1 list. As a consequence of this finding, allele Glu-D1w was reused for a distinct allele, and Glu-D1af was omitted and will be reused for a future allele, since the combinations of subunits that these alleles originally represented are no longer unique.
In {03124}, null alleles were observed for both Glu-D1-1 and Glu-D1-2,which, naturally, are not necessarily the same as those previously reported for this locus, meaning that composite alleles involving them in this study and corresponding to combinations apparently already listed in the Catalogue, may, in fact, represent novel alleles. It is also found that certain subunits of apparently identical relative mobility in SDS-PAGE showed different surface hydrophobocities in RP-HPLC; and the reverse situation was also observed (the same hydrophobicity, but different electrophoretic mobilities).
It was shown {03126} that the relatively small size of a y-type HMW glutenin subunit, named 12.4t (encoded by Glu-D1-1t {03124} - see the relevant list below) and carried by accession CPI110750 of Ae. tauschii, is due to the deletion of blocks of repetitive motifs, amounting to approximately 200 amino acids, probably caused by unequal crossing-over.
Note that the cultivar Fiorello is given as a standard for Glu-D1h encoding subunits 5+12 and for Glu-D1w encoding subunits 5*+10. An attempt to resolve this apparent conflict will be made in a future update.
Alleles and subunits at Glu-A1-1 and Glu-A1-2: Glu-A1-1 encodes X-type glutenins and Glu-A1-2 encodes y-type glutenins.