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1. H-FABP (heart-type fatty acid-binding protein) is an important fatty acid-binding protein that participates in the metabolism and intracellular transportation of lipids. This study was designed ...

RFamide-related peptides (RFRP) are synthesized by the hypothalamus and have a regulatory role in gonad development. The goal of this study was to investigate the association between SNP of the RFRP gene and the reproductive traits and hormone levels of Zhenning yellow chickens. The mRNA expression levels were detected based on different tissues, ages, and genotypes. Eleven mutation sites were detected in the RFRP gene, 4 of which were significantly related to reproductive traits and hormone levels. Association analysis revealed that A276G was associated with egg production at 300 d of age (EP300) and amount of prehierarchical follicles (P

Reproduction trait is one of the most important economic traits in poultry industry. This study was aimed to investigate the mRNA expression levels, single nucleotide polymorphisms (SNP) of POMC gene, and the association with reproduction traits in chickens. Five SNP (g.958 G > A, g.1374 G > C, g.1393 G > A, g.1817 C > T, and g.1918G > A) were detected in introns of POMC gene in 317 Zhenning yellow chickens. Association analysis revealed that g.958 G > A and g.1817 C > T showed significantly associations with fertilization rate, hatching rate of hatching eggs, and hatching rate of fertilized eggs in chickens. Simultaneously, g.1374 G > C and g.1918G > A were both associated with egg weight at 300 D of age (P < 0.05). The SNP of g.958 G > A, g.1393 G > A, and g.1817 C > T were all associated with E2 hormone levels (P < 0.05). The result of mRNA expression levels in different tissues showed that POMC mRNA expression level in the pituitary was higher than those in the other tissues and varied in different genotypes. In conclusion, the results in this study provided new evidences that polymorphisms of the POMC gene have potential effects on reproduction traits in chickens. The 5 SNP detected in this study could be potential markers for improving reproduction traits in chickens.

1. Fatty acid-binding proteins (FABP) are members of lipid-binding proteins, which participate in the metabolism and intracellular transportation of lipids. This study was designed to investigate t...

Myogenic differentiation 1 (MyoD1) belongs to the MyoD family and plays a key role in myogenesis and consequently, in determining muscle fiber characteristics. In this study, single nucleotide polymorphisms (SNPs) in the exons of MyoD1 were identified in 200 domestic pigeons (Columba livia) by direct DNA sequencing, and the association between MyoD1 polymorphisms and meat quality traits was analyzed. We found four novel variations (A2967G, G3044A, A3164C, and C3311G) in exon 3. The SNP A2967G is a synonymous mutation, while the other 3 SNPs are located in the 3' untranslated region. The analysis revealed 3 genotypes, in which allele A was the predominant allele in the SNP A2967G, while allele B was the predominant allele in the SNPs G3044A and A3164C. The mutations A2967G and G3044A were significantly associated with meat quality traits in pigeon. Pigeons with AA or AB genotypes had higher breast muscle concentrations of inosinic acid and intramuscular fat than those of BB genotype. Moreover, these 2 SNPs had significant effects on MyoD1 mRNA expression. The SNPs A2967G and G3044A were organized into 4 haplotypes, which formed 7 diplotypes. Association analysis showed that the diplotypes were not significantly associated with meat quality traits. Our results implied that associations do exist between MyoD1 gene polymorphisms and meat quality traits in domestic pigeons, and the AA and AB genotypes could be applied as genetic markers in marker-aid pigeon breeding.

In this study, nine non linear growth curve models were used to determine the goodness of fit by the body weight measurements of the total number of 178 partridges(Alectoris chukar), 93 females, and 85 males, respectively. The R2(coefficients of determination) values for the total partridges, females and males in Brody, Gompertz, Logistic, von Bertalanffy, asymptote regression,exponential, Monomolecular, Richards and Weibull-type were 0.985, 0.980 and 0.984, 0.997, 0.998 and 0.998, 0.996, 0.999 and 0.999, 0.995, 0.995 and 0.996, 0.985, 0.980 and 0.984, 0.891, 0.871 and 0.892, 0.985, 0.980 and 0.984, 0.997, 0.999 and 0.999, 0.997, 0.999 and 0.999, respectively. The R2 values for Gompertz, Logistic, von Bertalanffy, Richards and Weibull-type were >0.99, while the exponential (

PITX2 is expressed in and plays an important role in myocytes of mice, and it has effects on late myogenic differentiation in chickens. However, the expression profile and polymorphisms of PITX2 remain unclear in chickens. Therefore, the aim of the present study was to detect its expression and investigate single nucleotide polymorphisms (SNPs) within its exons and then to evaluate whether these polymorphisms affect body size as well as carcass traits in chickens. The expression analysis showed that the expression level of chicken PITX2 mRNA in the leg muscle and hypophysis was significantly higher (p &lt, 0.01) than those in other tissues. The results of polymorphisms analysis identified two SNPs (i.e., g.9830C &gt, T and g.10073C &gt, T) in exon 1 and 10 SNPs (i.e., g.12713C &gt, T, g.12755C &gt, T, g.12938G &gt, A, g. 3164C &gt, T, g.13019G &gt, A, g.13079G &gt, A, g.13285G &gt, A, g.13335G &gt, A, g.13726A &gt, G and g.13856C &gt, T) in exon 3, including four novel SNPs (i.e., g.9830C &gt, T, g.12713C &gt, A and g.13856C &gt, T). In the loci of g.10073C &gt, T and g.12713C &gt, T, chickens with the CT genotype had the highest (p &lt, 0.05 or p &lt, 0.01) breast depth and breast angle, respectively. For the locus of g.13335G &gt, A, chickens with the GG genotype had the highest (p &lt, 0.01) breast angle and shank circumference. For the locus of g.13726A &gt, G, chickens with the GG genotype had the highest breast width, fossil keel bone length and shank circumference. The locus of g.12713A &gt, G had significant effects on the PITX2 mRNA expression level in leg muscle. The H1H7 diplotype showed the highest shank circumference, and the H2H8 diplotype showed the highest breast muscle rate. The present research suggested that polymorphisms of the exons of the PITX2 gene were significantly associated with the body size and carcass traits of Wuliang Mountain Black-bone chickens and the PITX2 gene could be a potential candidate gene for molecular marker-aided selection in Wuliang Mountain Black-bone chickens and other chicken breeds.

Pro-opiomelanocortin (POMC) is a member of prohormone family and has important functions in stress response, skin pigmentation, thermoregulation and reproduction. In this study, the single nucleotide polymorphisms (SNPs) of POMC gene exons were detected by direct sequencing in 317 Zhenning yellow chickens. The sequencing results indicated there were seven mutation sites (g.1140C T, g.1185 T C, g.2085 T C, g.3566A C, g.3572 G A, g.3594 G A and g.3628 G A) and all of these were synonymous. Furthermore, seven haplotypes were formed and sixteen diplotypes were obtained. The associations between the POMC gene polymorphisms or diplotypes and reproduction traits were also analyzed. The association analysis results indicated that the SNP of g.1140C T was associated with egg production at 300 d of age (E300), fertilization rate (FR), hatching rate of hatching eggs (HEHR) and hatching rate of fertilized eggs (FEHR; P 0.05). The SNP of g.3566AC was associated with FR (P 0.05), SNP of g.3594GA was associated with egg weight at 300d of age (EW300; P 0.05), and SNP of g.3628GA was associated with HEHR and FEHR (P 0.01), respectively. Furthermore, chickens with H2H3 diplotype had greater EW300 and FR than those with H1H7 and H3H4 diplotypes (P 0.05). These results indicate the expression of the POMC gene had significant genotype effects on the reproduction traits of Zhenning yellow chickens, and that the H2H3 diplotype could be used as a potential genetic marker to improve the reproduction traits in chicken breeding.

Myostatin (MSTN) is a negative regulator of skeletal muscle growth and plays an important role in muscle development. In this research, we constructed a tissue expression profile of the pigeon MSTN gene in eight tissues and a spatio-temporal expression profile in the pectoral muscle using qRT-PCR method. And the pectoralis muscle fiber traits during pigeon post-hatching stages at 1, 7, 14, 21, and 28 D were analyzed through the paraffin sections. Then the correlations between the muscle fiber diameter, cross-sectional area, density, and the expression of MSTN in the pectoral muscle were analyzed. Results showed that MSTN mRNA was mainly expressed in breast muscle, heart, spleen, and kidney and it was almost unexpressed in the liver and lungs. Moreover, the MSTN mRNA expression level in breast muscle was significantly higher than that in other tissues (P < 0.05), and showed an interesting trend that it decreased in the first week and then increased with age. Meanwhile, decrease of myostatin transcripts was accompanied by the down-regulation of Myf5 and the up-regulation of MyoG during the first week post-hatching. In addition, the paraffin sections analysis results revealed that the diameter and cross-sectional area of pectoralis muscle fiber significantly increased with age (P < 0.05), and a significant positive correlation was shown between the MSTN gene expression level and muscle fiber diameter (P < 0.05). These fundamental researches might contribute to further understanding of the roles MSTN played in the post-hatching muscle fiber development in pigeon.

1. Adenylosuccinate lyase (ADSL) plays an important role in the synthesis of inosine monophosphate (IMP). In this trial, a total of 200 pigeons were sampled and slaughtered. Seven meat quality traits and 11 carcass traits were measured. DNA sequencing was used to detect nucleotide mutations, and associations between ADSL gene polymorphisms and meat quality and carcass traits were analysed. 2. Sequencing results showed that 9 nucleotide mutations were found in the exons of the ADSL gene. All the mutations were synonymous except C13065G, which caused a change in amino acids (Ser to Arg). In addition, two of the detected single nucleotide polymorphisms (SNPs) had significant associations with meat quality and carcass traits. 3. For the C13065G SNP located in exon11, the IMP content of breast muscle in AA and AB genotype was higher than in the BB genotype (P 0.01). The SNP G10696A located in exon10 was significantly associated with carcass rate, in which AA and AB genotype were higher than the BB genotype (P 0.01). 4. The results indicated that the ADSL gene has a close association with meat quality and carcass traits in domestic pigeons, and G10696A and C13065G SNPs could be applied as genetic markers in molecular marker-assisted breeding of pigeons.

1. Diacylglycerol acyltransferase (DGAT) plays an important role in the synthesis of triacylglycerol, but its effects on meat quality and carcass composition in pigeons are unclear. In this study, single-nucleotide polymorphisms (SNPs) in the exons of the DGAT2 gene were identified and analysed by using DNA sequencing methods in 200 domestic pigeons (Columba livia). The associations between DGAT2 polymorphisms and carcass and meat quality traits were also analysed. 2. Sequencing results showed that 5 nucleotide mutations were detected in exons 3, 4, 5 and 6 of the DGAT2 gene. The analysis revealed three genotypes (AA, AB and BB) in G18398T and G22484C, in which the AA genotype and A allele had the highest frequency. 3. In the SNP of G18398T located in exon 5, individuals with genotype BB had significantly higher meat quality and lower abdominal fat content than those with AA or AB genotype. In the SNP of G22484C located in exon 6, the genotype AA showed highest carcass trait values, while the genotype BB represented better meat quality, compared to AA and AB genotypes. 4. The results imply that DGAT2 gene has a close relationship with carcass and meat quality traits in pigeons, and the SNPs of G18398T and G22484C can be used as genetic markers for marker-assisted breeding in pigeon.

Previous study in our lab showed that indigenous Xianju chickens from free-range system (FRS) under summer conditions had lower egg production than those from conventional cage rearing system (CRS). The objective of this study was to preliminarily determine the FRS-dependent mechanism of depressing laying performance according to determining the effect of rearing systems on reproductive hormones secretion and their receptors mRNA expression in Xianju chickens reared under summer conditions. A total of 360 indigenous Xianju chickens were randomly allocated to CRS and FRS groups, each of which included 5 replicates of 36 hens. The experiment lasted between 21 and 29 wk of age. We found that the ovarian weight, numbers of small yellow follicles, and large white follicles in the FRS group were lower than those in the CRS group (P < 0.05). Changing from CRS to FRS increased serum concentrations of prolactin and decreased serum-luteinizing hormone and progesterone levels (P < 0.05). Gene expressions in the preovulatory follicles from FRS hens were upregulated for prolactin receptor and downregulated for luteinizing hormone receptor and progesterone receptor, compared to those from CRS hens (P < 0.05). It can be concluded that changing from CRS to FRS in the current experimental conditions depressed egg production traits in Xianju chickens by inducing a synergistic activity of reproductive hormones and the gene expressions of their receptors.