Adiponectin Gene Is Expressed in Multiple Tissues in the Chicken: Food Deprivation Influences Adiponectin Messenger Ribonucleic Acid Expression

Abstract

Adiponectin is a cytokine hormone originally found to be secreted exclusively by white adipose tissue. However, recent evidences suggest that adiponectin is also produced in brown adipose tissue and skeletal muscle. The present study investigated the expression of adiponectin mRNA in various tissues in the chicken. We also studied the effect of food deprivation on adiponectin gene expression in adipose tissue, liver, anterior pituitary gland, and diencephalon in the chicken. The open reading frame of chicken adiponectin cDNA consists of 735 nucleotides that were 65-68% homologous to various mammalian adiponectin cDNAs. The deduced amino acid sequence of chicken adiponectin contains 22 glycine-X-Y repeats (in which X and Y represent any amino acid) at the N-terminal end as found in the mammalian adiponectin. By RT-PCR and Northern analysis, we detected chicken adiponectin mRNA transcript in adipose tissue, liver, anterior pituitary gland, diencephalon, skeletal muscle, liver, kidney, ovary, and spleen but not in blood. Adiponectin mRNA expression in various tissues was quantitated using real-time quantitative PCR and found to be the highest in adipose tissue, followed by liver, anterior pituitary, diencephalon, kidney, and skeletal muscle. We also found that adiponectin mRNA quantity was significantly decreased after a 48-h food deprivation in adipose tissue, liver, and anterior pituitary gland but not in diencephalon. Our results provide novel evidence that, unlike mammals, adiponectin gene is expressed in several tissues in the chicken and that its expression is influenced by food deprivation.

Regulation of adiponectin and its receptors in rat ovary by human chorionic gonadotrophin treatment and potential involvement of adiponectin in granulosa cell steroidogenesis

“…Adiponectin has already been found in the ovaries of different species, including chicken (Maddineni et al 2005) and porcine (Lord et al 2005, Ledoux et al 2006. …”

“…Placental adiponectin mRNA expression is increased during pregnancy in rat, whereas AdipoR2 has the contrary pattern (Caminos et al 2005). Adiponectin, AdipoR1 and AdipoR2 are also present in porcine (Lord et al 2005, Ledoux et al 2006) and chicken ovaries (Maddineni et al 2005, Ramachandran et al 2006. In this latter species, results from our laboratory have shown that adiponectin mRNA expression is 30-fold higher in theca than in granulosa cells (Chabrolle et al in press).…”

Ghrelin affects stopover decisions and food intake in a long-distance migrant

“…The role of leptin in birds has been hotly debated in the past (71)(72)(73)(74), and the presence of this hormone in the avian circulation has not been convincingly demonstrated (71,(75)(76)(77). Adiponectin, orexin, and obestatin have been studied only at the level of gene cloning or gene expression, but few functional data are available (78)(79)(80)(81)(82). Thus, the present study represents a break-through with regard to the role of appetite-stimulating or -suppressing hormones as physiological modulators of stopover decisions during migration.…”

Adiponectin and its receptors are expressed in the chicken testis: influence of sexual maturation on testicular ADIPOR1 and ADIPOR2 mRNA abundance

“…We identified the expression of full-length mRNAs encoding chicken adiponectin, ADIPOR1 and ADIPOR2 by RT-PCR analysis and localized adiponectin-, ADI-POR1-, and ADIPOR2-ir cells in the chicken testis. Once thought to be primarily secreted by white adipose tissue, adiponectin has recently been found to be expressed in multiple tissues in the chicken (Maddineni et al 2005). In particular, adiponectin gene expression has been identified in chicken ovarian follicles (Chabrolle et al 2007).…”

“…Although adiponectin was once thought to be exclusively secreted from adipose tissue, we have recently detected expression of adiponectin and its receptors in multiple tissues in the chicken (Maddineni et al 2005, Ramachandran et al 2007. However, it is not known whether adiponectin or its receptors are expressed in the chicken testis.…”