Document Detail

Stable isotope tracer reveals that viviparous snakes transport amino acids to offspring during gestation.
MedLine Citation:
PMID:  22323198     Owner:  NLM     Status:  MEDLINE    
Viviparity and placentation have evolved from oviparity over 100 times in squamate reptiles (lizards and snakes). The independent origins of placentation have resulted in a variety of placental morphologies in different taxa, ranging from simple apposition of fetal and maternal tissues to endotheliochorial implantation that is homoplasious with mammalian placentation. Because the eggs of oviparous squamates transport gases and water from the environment and calcium from the eggshell, the placentae of viviparous squamates are thought to have initially evolved to accomplish these functions from within the maternal oviduct. Species with complex placentae have also been shown to rely substantially, or even primarily, on placental transport of organic nutrients for embryonic nutrition. However, it is unclear whether species with only simple placentae are also capable of transporting organic nutrients to offspring. Among viviparous squamates, all of the snakes that have been studied thus far have been shown to have simple placentae. However, most studies of snake placentation are limited to a single lineage, the North American Natricinae. We tested the abilities of four species of viviparous snakes - Agkistrodon contortrix (Viperidae), Boa constrictor (Boidae), Nerodia sipedon (Colubridae: Natricinae) and Thamnophis sirtalis (Colubridae: Natricinae) - to transport diet-derived amino acids to offspring during gestation. We fed [(15)N]leucine to pregnant snakes, and compared offspring (15)N content with that of unlabeled controls. Labeled females allocated significantly more (15)N to offspring than did controls, but (15)N allocation did not differ among species. Our results indicate that viviparous snakes are capable of transporting diet-derived amino acids to their offspring during gestation, possibly via placentation.
James U Van Dyke; Steven J Beaupre
Related Documents :
3735128 - Effect of reduced hepatic energy state on acetaminophen conjugation in rats.
996548 - Is there selection against wobble in codon-anticodon pairing?
22577978 - Some macronutrient content in mycelia and culture broth of medicinal mushrooms cultivat...
2874138 - The purine nucleotide cycle and ammoniagenesis in rat kidney tubules.
6815718 - Arachidonic acid metabolism in rat pancreatic acinar cells: calcium-mediated stimulatio...
25425658 - Mutation analysis and molecular modeling for the investigation of ligand binding modes ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of experimental biology     Volume:  215     ISSN:  1477-9145     ISO Abbreviation:  J. Exp. Biol.     Publication Date:  2012 Mar 
Date Detail:
Created Date:  2012-02-10     Completed Date:  2012-05-29     Revised Date:  2012-06-19    
Medline Journal Info:
Nlm Unique ID:  0243705     Medline TA:  J Exp Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  760-5     Citation Subset:  IM    
601 SCEN, Department of Biological Sciences, 1 University of Arkansas, Fayetteville, AR, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acids / metabolism*
Biological Transport
Nitrogen Isotopes / analysis
Snakes / embryology*,  metabolism*
Viviparity, Nonmammalian*
Reg. No./Substance:
0/Amino Acids; 0/Nitrogen Isotopes

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Mechanisms underlying parallel reductions in aerobic capacity in non-migratory threespine sticklebac...
Next Document:  Geometry of compensatory feeding and water consumption in Drosophila melanogaster.