title: Bone-remodeling transcript levels are independent of perching in end-of-lay white leghorn chickens.
abstract: Osteoporosis is a bone disease that commonly results in a 30% incidence of fracture in hens used to produce eggs for human consumption. One of the causes of osteoporosis is the lack of mechanical strain placed on weight-bearing bones. In conventionally-caged hens, there is inadequate space for chickens to exercise and induce mechanical strain on their bones. One approach is to encourage mechanical stress on bones by the addition of perches to conventional cages. Our study focuses on the molecular mechanism of bone remodeling in end-of-lay hens (71 weeks) with access to perches. We examined bone-specific transcripts that are actively involved during development and remodeling. Using real-time quantitative PCR, we examined seven transcripts (COL2A1 (collagen, type II, alpha 1), RANKL (receptor activator of nuclear factor kappa-B ligand), OPG (osteoprotegerin), PTHLH (PTH-like hormone), PTH1R (PTH/PTHLH type-1 receptor), PTH3R (PTH/PTHLH type-3 receptor), and SOX9 (Sry-related high mobility group box)) in phalange, tibia and femur. Our results indicate that the only significant effect was a difference among bones for COL2A1 (femur > phalange). Therefore, we conclude that access to a perch did not alter transcript expression. Furthermore, because hens have been used as a model for human bone metabolism and osteoporosis, the results indicate that bone remodeling due to mechanical loading in chickens may be a product of different pathways than those involved in the mammalian model.
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. mddale@ilstu.edu.
authors.forename: Maurice D
authors.initials: MD
authors.lastname: Dale
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. mortimr2@illinois.edu.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Mortimer
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. srkolli@gmail.com.
authors.forename: Santharam
authors.initials: S
authors.lastname: Kolli
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. eachramowicz@gmail.com.
authors.forename: Erik
authors.initials: E
authors.lastname: Achramowicz
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. borchert@southalabama.edu.
authors.forename: Glenn
authors.initials: G
authors.lastname: Borchert
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. sajulian@ilstu.edu.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Juliano
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. sdhalkyard@gmail.com.
authors.forename: Scott
authors.initials: S
authors.lastname: Halkyard
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. nseitz@ilstu.edu.
authors.forename: Nick
authors.initials: N
authors.lastname: Seitz
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. cgatto@ilstu.edu.
authors.forename: Craig
authors.initials: C
authors.lastname: Gatto
authors.affiliation: Department of Animal Sciences, Purdue University, 125 South Russell St, West Lafayette, IN 47907, USA. phester@purdue.edu.
authors.forename: Patricia Y
authors.initials: PY
authors.lastname: Hester
authors.affiliation: School of Biological Sciences, Illinois State University, Normal, IL 61701, USA. adavid@ilstu.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Rubin
mesh_terms: D000375:Aging; D000818:Animals; D016723:Bone Remodeling / Q000235:genetics*; D002645:Chickens; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D005260:Female; D005269:Femur / Q000378:metabolism*; D053244:Osteoprotegerin / Q000235:genetics / Q000378:metabolism; D044162:Parathyroid Hormone-Related Protein / Q000235:genetics / Q000378:metabolism; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism; D018016:Receptors, Parathyroid Hormone / Q000235:genetics / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D013977:Tibia / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D024043:Collagen Type II; D053244:Osteoprotegerin; D044162:Parathyroid Hormone-Related Protein; D053245:RANK Ligand; D018016:Receptors, Parathyroid Hormone; D055758:SOX9 Transcription Factor