Lipovitellins and phosvitins of the fertilized eggs during embryo growth in the oviparous lizard Podarcis sicula

Abstract

In the lizard Podarcis sicula, the major vitellogenin (VTG)-derived yolk proteins, lipovitellins and phosvitins, were extracted from the yolk globules of laid and fertilized eggs at different periods of incubation up to 44 days close to hatching. Embryonic development was almost over at this time. Yolk proteins were isolated by precipitation in saturated (NH(4))(2)SO(4), separated on SDS-PAGE and detected by Western blotting with homologous polyclonal anti/VTG antibody. Two lipovitellins of 110 and 116 kDa were always present in the yolk of laid eggs after 1, 10, 18, and 44 days from oviposition. Both these proteins were glycosylated and were recognized by the anti/VTG antibody; their N-terminal sequences were analyzed. Four phosvitins were detected in freshly laid eggs, but their number decreased during incubation, and after 44 days only a single protein of approximately 6.5 kDa was present. The results indicated that, in this lizard, during embryonic development, lipovitellins remain unchanged, whereas the phosphorylated components of yolk undergo continuous degradation.

A Novel Pattern of Yolk Processing in Developing Snake Eggs (Colubridae: Lampropeltini) and its Functional and Evolutionary Implications

“…Not only is this pattern similar to that of the corn snake Pantherophis guttatus (Powers and Blackburn, ), but it appears to resemble that of certain lizards. Sparse information from light microscopy suggests that yolk‐filled endodermal cells surround small blood vessels in the eggs of two oviparous lizards (Romano et al., ; Stewart et al., ) and a viviparous one (Weekes, ) (see Elinson et al., ). A recent light microscopic study has examined yolk sac development in detail in three Australian skinks, Lampropholis guichenoti, Saproscincus mustelinus , and Morethia adelaidensis (Stewart and Thompson, ).…”

Amniote yolk sacs: diversity in reptiles and a hypothesis on their origin

“…4B). A meshwork also develops in the yolk of the lizard Podarcis sicula (Lacertidae) (Romano et al, 2002). The presence of yolkfilled endodermal cells associated with blood vessels within the yolk sac cavity also has been described in the family Scincidae in both a viviparous species (Weekes, 1927) and an oviparous one (Stewart et al, 2012).…”

Quantitative composition of vitellogenin‐derived yolk proteins and their effects on viability of embryos and larvae of common dentex (Dentex dentex), a marine pelagophil teleost

“…Embryogenesis and larvae development of teleosts such as the other oviparous (nonplacental or nontrophotenic) vertebrate with meso and megalecithal eggs is dependent on proteolytic cleavage of the vitellogenin (Vtg)-derived yolk proteins (Romano et al, 2002) (lipovitellins, Lvs, phosvitins, Pvs (see Sawaguchi et al, 2006), b 0 -component, b 0 -c (Matsubara and Sawano,'95) and C-terminal domine, C-t (Matsubara et al, 2003)) to generate a supply of free amino acids (Engelmann,'79;Hagedorn and Kunkel,'79), as a resource for energy production (Finn et al,'96), as a source for protein synthesis during development (Ohkubo and Matsubara, 2002), as osmotic active compounds (Fabra et al, 2005(Fabra et al, , 2006Finn, 2007;Finn and Kristoffersen, 2007) along with inorganic ions (Selman et al, 2001;Finn et al, 2002;Fabra et al, 2006).…”