Phylogenetic expression of Galα1-4Gal on avian glycoproteins: Glycan differentiation inscribed in the early history of modern birds

Abstract

Glycoproteins containing Gal␣1-4Gal (galabiose) had been rarely found in vertebrates, except in a few species of birds and amphibians. We had previously reported that pigeon (Columba livia) egg white and serum glycoproteins are rich in N-glycans with Gal␣1-4Gal at nonreducing termini. To investigate the origin of Gal␣1-4Gal expression in avian evolution, we examined the presence of Gal␣1-4Gal glycoproteins in egg whites from 20 orders, 88 families, 163 genera, and 181 species of birds, as probed by Western blot with Griffonia simplicifolia-I lectin (terminal ␣-Gal͞GalNAc-specific) and anti-P1 mAb (Gal␣1-4Gal␤1-4GlcNAc␤1-specific). One of the significant observations is the total absence of Gal␣1-4Gal glycoproteins in Struthioniformes (four species), Tinamiformes (three species), Craciformes (two species), Galliformes (14 species), and Anseriformes (10 species), which are phylogenetically separated from other orders at earlier stage of modern bird diversification (100 -65 million years ago). The presence or absence of Gal␣1-4Gal glycoproteins in other avian orders varied by the species (104 species positive, and 44 species negative), even though some of them belong to the same order or family. Our results revealed that the expression of Gal␣1-4Gal glycoproteins is not rare among avians, and is correlated with the phylogeny. The expression was most likely differentiated at earlier stage of diversification in modern birds, but some birds might have lost the facility for the expression relatively recently.

New candidate species most closely related to penguins

“…Recent molecular and morphological studies have yielded a consensus that the basal split among extant birds resides between palaeognath (ratites and tinamous) and neognaths (all other extant birds) (Cracraft, 1988(Cracraft, , 2001Cracraft and Mindell, 1989;Livezey and Zusi, 2001;van Tuinen et al, 2000;Edwards et al, 2002;Garcia-Moreno et al, 2003;Sorenson et al, 2003;Chubb, 2004;Cracraft et al, 2004;Fain and Houde, 2004;Harrison et al, 2004;Suzuki et al, 2004). This basal divergence in the avian tree is now well established, but the higher-order relationships and those among orders of neognaths birds remain unclear even among recent molecular studies, necessitating a reexamination of the phylogeny by including data from diverse bird species.…”

Molecular Cloning of Pigeon UDP-galactose:β-d-Galactoside α1,4-Galactosyltransferase and UDP-galactose:β-d-Galactoside β1,4-Galactosyltransferase, Two Novel Enzymes Catalyzing the Formation of Galα1–4Galβ1–4Galβ1–4GlcNAc Sequence

“…However, we found that the expression of Gal␣1-4Gal on glycoproteins is correlated with the avian phylogeny (8). To investigate the enzyme catalyzing the formation of Gal␣1-4Gal on glycoproteins, we successfully isolated the cDNA encoding pigeon ␣4GalT(Gal), which had not been identified previously.…”

Structural and Physicochemical Characteristics of Novel Basic Proteins Isolated from Duck Egg White

“…This result corresponds to the close evolutionary relationship within Galloanserae according to the absent of Gal 1-4Gal in all tested glycoproteins of Galloanserae EW. 25) In addition, the relationship of meleagrin with ''similar to meleagrin,'' from the same order (Galliformes), is closer than with cygnin or dBPS 2 , from the different order (Anseriformes). A close relationship within Galliformes order than with other from Anseriformes order was also suggested in ovotransferrin.…”