A higher content of Tn and sialyl-Tn receptors in glycophorin A of blood group N than in that of blood group M was suggested by reactions with anti-Tn lectins. Analysis of [^-elimination products of two blood group M and two blood group N preparations by gas liquid chromatography-mass spectrometry showed that GalNAc- -ol was detectable in minor amounts in all analyzed samples and its content was higher in the products obtained from desialylated antigens. Moreover, the content of Gal N Ac- -ol detected in blood group N samples was almost twice as high as in respective blood group M samples. Since blood group M and N antigens differ in two amino-acid residues, our results support the existence of sequence-dependent differences in efficiency of substitution of glycophorin GalNAc-Ser/Thr residues with galactose.
In this study a wide range of genetic markers (12 microsatellites, 7 blood-group loci, 10 blood-protein loci) and mitochondrial DNA (mtDNA) were used to assess genetic diversity in Polish Heavy horses. Three random samples were sequenced for 421 bp of the mitochondrial D-loop region, but no clear phylogenetic patterns were seen in mtDNA variation. Both heterozygosity and diversity levels are fairly high in Polish Heavy horses. In phylogenetic analysis the draught horses form a distinct cluster that pairs with the true pony breeds. Within this ‘cold-blooded’ group, the Polish Heavy Horse clusters most closely with the Posavina breed from Croatia and the Breton breed from France. From the standpoint of genetic conservation, the Polish Heavy Horse does not appear to be in jeopardy.