Expression and relationship of the insulin-like growth factor system with posthatch growth in the Korean Native Ogol chicken

Abstract

Insulin-like growth factors (IGF) act as regulators that modulate proliferation and differentiation of various cells. Also, IGF are involved in metabolism and body growth by regulating the synthesis and degradation of glycogen and proteins in animals. However, the effect of IGF system on body growth in poultry including Korean Native Ogol chickens (KNOC) has not been thoroughly studied. Therefore, this study was performed to investigate the expressions of IGF system and the relationship of IGF with body growth during posthatch growth in KNOC. Sera and organs were collected at hatch and at 1, 3, 5, and 7 wk. The mRNA expressions of IGF, IGF-I receptor, and IGF binding protein (IGFBP)-2 were quantitatively analyzed by reverse transcription (RT)-PCR. The IGF concentrations were measured by heterologous RIA, and the expression of IGFBP-2 was detected by Western ligand blotting. The body weight of KNOC rapidly increased during the experimental period, and increase in breast muscle weight was 5-fold from 1 to 3 wk. Although the circulating IGF-I concentration gradually increased, the level of IGF-I in breast muscle rapidly declined during growth period. The IGF-II expression was not similar to IGFBP-2 during postnatal growth. Moreover, the breast muscle IGF-II concentration was mainly correlated with body growth at 7 wk and breast muscle IGF-I at 1 and 5 wk. Taken together, the present study suggested that the endocrine manner of IGF-I was more important than auto/paracrine actions in body growth of KNOC and that expression of IGF-II was involved in body growth and IGF-I during posthatch growth of KNOC.

Expression profile of insulin-like growth factor system genes in muscle tissues during the postnatal development growth stage in ducks

“…Breast muscle displayed the highest expression of IGF-I mRNA at week 1. It then declined, consistent with the observations of other researchers; for example, Yun et al (2005) reported a dramatic decline in IGF-I expression in the breast muscles of Korean native Ogol chickens. These results suggest that the endocrine actions of IGF-I are more important than auto/paracrine actions in early postnatal growth in ducks.…”

“…These conflicting results have suggested that the association of IGF-I with the body growth of chickens depends on strain, nutrition, age, and sex. Yun et al (2005) have reported that the concentration of breast muscle IGF-II is negatively correlated with body growth at weeks 3 and 7, in contrast to the results of previous studies (Spencer et al, 1996;Yun et al, 2005;Llewellyn et al, 2007). Our results showed that IGF-II mRNA levels were negatively correlated with BMW and LMW, and especially that IGF-II mRNA levels were negatively correlated with LMW at week 4 (P < 0.05).…”

“…IGF-IR expression in breast muscle is strong during the early postnatal period in chickens and then decreases (Yun et al, 2005). Our results showed that breast muscle displayed the highest expression the IGF-IR mRNA at week 3.…”

Selective transport of long-chain fatty acids by FAT/CD36 in skeletal muscle of broilers

“…Fragments (75 to 150 bp) of the target genes (including FATP-1, mFABP, FAT/CD36, caveolin-1 and b-actin) were cloned and inserted into pMD18-T simple vectors as standard plasmids. Table 1 presents the forward and reverse primers for the tested genes and for the internal reference gene (b-actin; Yun et al, 2005). Q-PCR (SYBR Green Kit, TOYOBO, Osaka, Japan) technology was employed to detect the mRNA expression level.…”

Effects of Leptin on Lipid Metabolism and Gene Expression of Differentiation-Associated Growth Factors and Transcription Factors during Differentiation and Maturation of 3T3-L1 Preadipocytes

“…First-strand complementary DNA (cDNA) was synthesized using 1 μg of total RNA as template, 0.3 μg of a mixture of random primers (Gibco) and AccPower TM RT Premix (Bioneer Co., Daejeon, Korea) in a total volume of 20 μl according to the manufacturer's instruction as previously described [30]. The targeted fragment of cDNA per each of the differentiation-associated genes (Table 1) was amplified by PCR using 5 μl of the RT product, 20 pmoles of each of the primer pair and the AccuPower TM PCR premix (Bioneer) under the conditions also shown in Table 1.…”