QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online September 5, 2008
Journal of Experimental Biology 211, 2960-2968 (2008)
Published by The Company of Biologists 2008
doi: 10.1242/jeb.017897

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wagner, E. C. Articles by Williams, T. D. Search for Related Content PubMed PubMed Citation Articles by Wagner, E. C. Articles by Williams, T. D. Pubmed/NCBI databases Substance via MeSH Social Bookmarking                         What's this?

Hematological changes associated with egg production: direct evidence for changes in erythropoiesis but a lack of resource dependence?

Emily C. Wagner^*, Christine A. Stables and Tony D. Williams

Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6

^* Author for correspondence at present address: Women's Health Research Institute, Provincial Health Services Authority, Room E208–4500 Oak Street (Box 42), Vancouver, British Columbia, Canada V6H 3N1 (e-mail: ewagner3{at}cw.bc.ca)

Accepted 14 July 2008

Reductions in hematological parameters among laying birds are well reported, but the cause of this anemia is not known. We tested specific predictions generated from several, non-mutually exclusive hypotheses for mechanisms underlying reproductive anemia associated with egg production (hemodilution, transient suppression of erythropoiesis, resource dependence) in relation to (1) the time-course of development and recovery from anemia, (2) changes in specific hematological traits, and (3) the effect of diet quality, in female zebra finches (Taeniopygia guttata). Female zebra finches showed marked decreases in hematocrit (6%), red blood cell counts (8%), and plasma hemoglobin concentration (9%) during egg production, even on a high-quality ad libitum diet, consistent with an effect of hemodilution associated with yolk precursor production. However, our results provide strong support for the hypothesis that erythropoiesis is transiently suppressed during egg-laying and that the recovery from anemia is relatively long-lasting, extending through incubation and hatching periods. Decreased hematocrit, red blood cell counts, and hemoglobin concentration did not recover at clutch completion, but showed evidence of recovery to baseline pre-breeding levels at hatching. More importantly, there was significant time-dependent variation in the proportion of reticulocytes, which increased at clutch completion but peaked at hatching 10–12 days after clutch completion, and in mean red blood cell volume, which showed a significant increase at clutch completion; consistent with enhanced production and release of larger immature cells into the circulation following suppression of erythropoiesis. Finally, we found no evidence for resource dependence of anemia associated with egg production in relation to diet quality, i.e. exogenous lipid and protein resources available to the laying female. This study demonstrates that transient suppression of erythropoiesis and, subsequently, increased reticulocytosis, are key components of reproductive anemia in egg-laying females.

Key words: anemia, cost of reproduction, egg production, erythropoiesis, estrogen, zebra finch

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

Related articles in JEB:

BIRDS LAY OFF BLOOD CELLS WHEN LAYING EGGS

Kathryn Phillips
JEB 2008 211: ii. [Full Text]  

This article has been cited by other articles:

				K. Phillips BIRDS LAY OFF BLOOD CELLS WHEN LAYING EGGS J. Exp. Biol., September 15, 2008; 211(18): ii - ii. [Full Text] [PDF]