TY - JOUR
T1 - Expression of hypothalamic GnRH-I mRNA in the female turkey at diverent reproductive states and following photostimulation
AU - Kang, ASeong W.
AU - Thayananuphat, Aree
AU - Rozenboim, Israel
AU - Millam, James R.
AU - Proudman, John A.
AU - El Halawani, Mohamed E.
PY - 2006/1/1
Y1 - 2006/1/1
N2 - In birds, changes in hypothalamic gonadotropin-releasing hormone-I (GnRH-I) content and release are correlated with reproductive stages. This study examined the distribution and expression level of GnRH-I mRNA in anatomically discrete hypothalamic nuclei throughout the turkey reproductive cycle and following photostimulation. GnRH-I mRNA expression was determined using in situ hybridization in non-photostimulated (NPS), egg-laying (LAY), incubating (INC) and photorefractory (REF) hens. Overall, GnRH-I mRNA expression was greatest in the nucleus commissurae pallii (nCPa) and around the organum vasculosum lamina terminalis (OVLT), with less expression observed in the nucleus septalis lateralis (SL), cortico-habenula cortico-septum area, and within the nucleus preopticus medialis. GnRH-I mRNA expression was signiWcantly increased in nCPa, OVLT, and SL after NPS hens (6L:18D) were exposed to a 30 or 90 min pulse of light beginning 14 h after Wrst light (dawn). GnRH-I mRNA abundance within nCPa, OVLT and SL was greater in LAY than in NPS and INC hens, while mRNA expression was least in REF hens. These results indicate that GnRH-I mRNA expression in birds is sensitive to light stimulation during the photosensitive period and can be used to more precisely characterize their diVerent reproductive stages.
AB - In birds, changes in hypothalamic gonadotropin-releasing hormone-I (GnRH-I) content and release are correlated with reproductive stages. This study examined the distribution and expression level of GnRH-I mRNA in anatomically discrete hypothalamic nuclei throughout the turkey reproductive cycle and following photostimulation. GnRH-I mRNA expression was determined using in situ hybridization in non-photostimulated (NPS), egg-laying (LAY), incubating (INC) and photorefractory (REF) hens. Overall, GnRH-I mRNA expression was greatest in the nucleus commissurae pallii (nCPa) and around the organum vasculosum lamina terminalis (OVLT), with less expression observed in the nucleus septalis lateralis (SL), cortico-habenula cortico-septum area, and within the nucleus preopticus medialis. GnRH-I mRNA expression was signiWcantly increased in nCPa, OVLT, and SL after NPS hens (6L:18D) were exposed to a 30 or 90 min pulse of light beginning 14 h after Wrst light (dawn). GnRH-I mRNA abundance within nCPa, OVLT and SL was greater in LAY than in NPS and INC hens, while mRNA expression was least in REF hens. These results indicate that GnRH-I mRNA expression in birds is sensitive to light stimulation during the photosensitive period and can be used to more precisely characterize their diVerent reproductive stages.
KW - Avian hypothalamus
KW - GnRH-I mRNA expression
KW - In situ hybridization
KW - Photostimulation
KW - Turkey reproductive cycle
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U2 - 10.1016/j.ygcen.2005.10.017
DO - 10.1016/j.ygcen.2005.10.017
M3 - Article
C2 - 16427052
AN - SCOPUS:33646903476
SN - 0016-6480
VL - 146
SP - 86
EP - 94
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 2
ER -