ETUDE DE L'HEREDITE DE PHOSPHATASES ACIDES CHEZ LE DACTYLE (DACTYLIS GLOMERATA) DIPLOIDE ET TETRAPLOIDE

Starch gel electrophoresis of leaves of diploid and more particularly tetraploid orchard grass (Dactylis glomerata L.) from cultivars as well as natural populations disclosed several anodal stable bands with fast migration and phosphatasic activity. Six different phenotypes with one band, many others with three regular bands or six bands (only in the tetraploid individuals), were observed, showing the dimeric structure of the enzymes. Inheritance studies showed one polymorphic locus with six codominant alleles AcPH 11.00, AcPH 10.95, AcPH 10.90, AcPH 10.88, AcPH 11.02 and AcPH 11.04 with differences in enzymatic expression. AcPH 1.00 and AcPH 10.90 have been found in the two ploidy levels. Results from the tetraploid progenies involved tetravalents in meiosis for individuals originating from cultivars but bivalents in the wild plants. The two loci AcPH 1 and GOT 1 (this last one coding for a glutamate oxaloacetate transaminase) are not linked and seem to be located on different chromosomes.

Dissociation-recombination of sunflower seed acid phosphatase

Formal genetic studies of sunflower (Helianthus annuus) seed acid phosphatase (ACP, E.C. 3.1.3.2) had suggested that the functional enzyme consists of two polypeptide subunits. The dimeric quaternary structure was demonstrated by dissociation-recombination procedures. Dissociation of electrophoretically distinct homodimers was effected upon freezing of extracts in a pH 8-9 buffer containing 1 M NaCl and 0.1 M 2-mercaptoethanol. Reassociation, as indicated by the formation of the hybrid isozyme, occurred during 12 hr dialysis against a pH 7.0 buffer.