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Expression of calcium transport proteins in the extraembryonic membranes of a reproductively bimodal lizard
Author(s) -
Ecay Tom W,
Fregoso Santiago P,
Linville Brent J,
Stewart James R,
Heulin Benoit
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1048.7
Subject(s) - oviparity , calcium , biology , eggshell , yolk , lizard , chorioallantoic membrane , microbiology and biotechnology , calcium binding protein , embryo , anatomy , zoology , medicine , ecology
Oviparous reptile eggs contain two sources of calcium to support embryonic growth and development: yolk and eggshell. Viviparous reptile eggs have attenuated shells that are not calcified, eliminating a source of embryonic calcium. For most viviparous reptiles, placental calcium transport compensates for lost shell calcium. Zootoca vivipara is a lizard with both oviparous and viviparous populations. We studied the developmental expression of calcium transport proteins (calbindin‐D28K, plasma membrane Ca 2+ ‐ATPase, and carbonic anhydrase II) in Z. vivipara eggs from viviparous and oviparous populations to test the hypothesis that calcium transport protein expression is independent of calcium source (shell or placenta). The pattern of yolk sack calbindin‐D28K expression does not differ between ovivparous and viviparous embryos as anticipated as this calcium source is common to both modes. Consistent with our starting hypothesis, calcium transport protein expression by the chorioallantois, which mediates shell or placental calcium transport, does not differ between reproductive modes. Similar patterns of calcium transport protein expression and embryonic calcium accumulation in oviparous and viviparous embryos suggest that the plasticity of uterine calcium delivery (to eggshell or for placental transfer) facilitates the evolution of reproductive mode in this lineage. (NSF grant IOB‐06515695)