Yolk proteins and their plasmatic precursor in the tetraploid Odontophrynus americanus (Amphibia, Anura).

The vitellogenin of Odontophrynus americanus is a large (426.5 kDa) plasmatic protein. The vitellogenin is composed of two different phosphoglycopeptides: VTG1 = 207.5 kDa and VTG2 = 202.4 kDa. The vitellins originating from the partial proteolysis of the plasmatic vitellogenin on the ovary cells are composed of lipovitellins and phosphoproteins. Lipovitellin 1 has two glycopeptides with different amino acid sequences as determined by peptide mapping (LV1 alpha, 104.6 kDa; and LV1 beta, 92.6 kDa). Lipovitellin 2 is composed of three kinds of polypeptides (LV2 alpha, 31.7 kDa; LV2 beta, 29.7 kDa; LV2 gamma, 27.8 kDa). There are three phosphopeptides in the yolk: phosvitin (PV, 37.4 kDa) and phosvettes 1 (PVT1, 27.7 kDa) and 2 (PVT2, 26.1 kDa).