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ABSTRACT. The objective of this study was to investigate the effects of sex and slaughter age of chickens on fatty acid composition and TBC1D1 gene expression in 4 different tissues: breast muscle, thigh muscle, abdominal fat, and subcutaneous fat. Sixty Erlang mountainous chickens (hybrid SD02 x SD03) were raised under the same conditions and slaughtered at 8, 10, and 13 weeks of age. The results showed that the sex of the animal significantly affected the content of arachidic acid (C20:0), sinapic (C22:1), linoleic (C18:2n-6), eicosapentaenoic (C20:5n-3), and docosahexaenoic acids (C22:6n-3), whereas other fatty acid contents were not affected. Age had a significant effect on most monounsaturated fatty acids, except for octadecenoic acid (C18:1). TBC1D1 mRNA was abundant in all tissues at all 3 ages of slaughter. Cocks exhibited higher TBC1D1 7705 TBC1D1 gene expression in chicken ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 7704-7714 (2015) mRNA levels than hens in the thigh muscle and abdominal fat at 10 and 13 weeks, respectively.

This study aimed at examining the effect of overfeeding on the activity of the mTOR pathway in the liver and muscle tissues of Gang geese. Eighty healthy male Gang geese were reared under the same feeding conditions, and were divided at 14 weeks of age into a control group and an overfed group. All birds were slaughtered after three weeks of over feeding. Gene expression and protein content of several genes involved in the mTOR pathway were evaluated. The results showed that the gene expression of mTOR, raptor, and rictor, and the protein contents of mTOR and PI3K were higher in liver, breast muscle, and leg muscle of the overfed group than that of control group. However, the S6K expression level was clearly lower in the liver of the overfed group than that of control group, and there was no evident difference in both breast muscle and leg muscle between the control group and the overfed group. These results suggest that overfeeding induces the activity of raptor, rictor, and mTOR, and that mTOR signaling pathway was closely linked with PI3K pathway in the evaluated geese. 294

BMP6, a member of the subfamilies of the morphogenetic proteins (BMPs), plays a crucial role in osteogenic and chondrocyte differentiation in vitro and stimulates chondrogenesis, making chondrocytes differentiate on their terminal stage. The objective of this study is to explore the relationship between polymorphism of BMP6 gene and slaughter traits in chicken respectively. We screened the exonic and intronic regions of BMP6 gene by DNA pool construction and amplified DNA fragment by PCR, and finally, we got nine SNPs. Association analysis revealed that BMP6 had no significant association among all slaughter traits in Yellow bantam chicken. However, BMP6 had a significant difference with femur weight, tibia weight, femur length (p<0.05), and was extremely significant with tibia length (p<0.01) in Avian chicken. Moreover, femur perimeter also had significant correlation with BMP6 in Avian chicken. These results provide useful information for further investigation on the function of chicken BMP6 gene.

ABSTRACT. The sterol regulatory element-binding transcription factor 2 gene (SREBF2) plays an important role in regulating lipid homeostasis. To reveal the genetic factors that underlie carcass fat deposition in chickens, we cloned the coding DNA sequence of chicken SREBF2, investigated SREBF2 mRNA expression levels in various tissues, detected single nucleotide polymorphisms (SNPs) in the exon regions of the gene, and conducted association analyses between single markers/haplotypes and carcass traits. The entire 2859-bp cDNA sequence of chicken SREBF2 that encoded 952 amino acids was obtained and characterized. SREBF2 mRNA was highly 2 F. Ye et al. Genetics and Molecular Research 15 (3): gmr.15038514 expressed in the uropygial gland, followed by the liver, breast muscle, and leg muscle. Ten SNPs were detected, and four (g.49363077T>A, g.49357503C>T, g.49355533G>A, and g.49354641G>A) were novel. When analyzing the associations between the single mutations and carcass traits, significant differences were found in three SNPs and g.49357915G>A was highly significantly associated with most carcass traits, except for abdominal fat weight and sebum thickness. In addition, haplotype combinations that were constructed using the SREBF2 SNPs were associated with breast muscle weight. Chickens with the combined genotype H21H21 had the highest live weight, carcass weight, eviscerated weight, and semi-eviscerated weight values. To the best of our knowledge, this is the first study conducted on chicken SREBF2 polymorphisms, which are predictive of the genetics that underlie the economic performance of chickens.

There is increasing evidence that bone morphogenetic protein 6 (BMP6) plays critical roles in regulating various stages of ovarian follicle development in mammals. However, the mechanisms of regulation of BMP6 in the chicken ovary remain unclear. In this study, mRNA and protein expression level of BMP6 in chicken ovarian follicles at different development stages were determined by qRT-PCR and western blot separately. Different concentrations of BMP6 protein and FSH were added to the culture medium, and the effects to proliferation of granulose cells were detected, further effect on expression pattern of progesterone synthesis associated genes were also analyzed by qRT-PCR and Western blotting and the secretion of progesterone was detected by ELISA. The results showed that mRNA and protein expression level of BMP6 increased significantly in the follicle with the development of follicle (p<0.05) and reached a peak at F1 follicle. Adding concentration of 50ng/ml and 100ng/ml of BMP6 protein promoted significantly the proliferation of granulosa cells (p<0.05), as well as up-regulated the expression of Steroid hormone synthesis acute regulatory protein (StAR) and 3β-hydroxysteroid dehydrogenase (3β-HSD) genes in mRNA and protein level. Meanwhile, the secretion of progesterone was significantly higher in the group that added BMP6 and FSH separately than blank control group (p<0.05) and reached a peak in the group that both added BMP6 and FSH. Collectively, these findings highlight that BMP6 is associated with proliferation of follicular cells and the synthesis of progesterone, which indicated that it took an important role in the follicular development of chicken.

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