Animals ; Bacterial Proteins ; genetics ; metabolism ; Chickens ; microbiology ; Escherichia coli ; genetics ; metabolism ; Genotype ; beta-Lactamases ; genetics ; metabolism

OBJECTIVE: To investigate the effect of form-deprivation on level of gelatinase in the posterior sclera in chicks. METHODS: Fifty 1-day-old chicks were monocularly deprived to establish the animal model of form-deprivation myopia (FDM). According to the duration of form-deprivation the experimental chicks were divided randomly and equivalently into 5 groups, which were deprived for 3, 7, 14, 21 and 30 days respectively. Meanwhile the other eyes of the deprived chicks were used as self-control groups and chicks of the same days were chosen randomly as the normal control groups for each FDM group. At each form-deprivation point the changes of degree of diopters and axial length of chicks in each group were recorded. The levels of gelatinase in posterior sclera of the experimental eyes were measured by gelatin enzymography. RESULTS: Compared with the normal and self-control groups, the levels of MMP-2 activity in FDM groups were much higher (P <0.01). With the increase of the time of monocular deprivation these changes became more significant and reached the top after 14 days' deprivation with an inter-group statistical difference (P <0.01). The dynamic changes of MMP-2 activity were the same as those of axial length and degree of diopters in each experimental groups. There was positive correlation between the MMP-2 activity and axial length (r = 0.989, P < 0.01). But there was a negative correlation between the MMP-2 activity and refractive degree. CONCLUSION Increase of MMP-2 activity in the posterior sclera of chicks would be a direct key factor to trigger sclera ECM remodeling process in chick FDM.
Animals ; Chickens ; Gelatinases ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Myopia ; enzymology ; etiology ; Sclera ; enzymology

OBJECTIVETo screen the differently expressed proteins related to regulating the depolymerization of microtubules in the spinal cord of hens exposed to tri-o-cresyl phosphate (TOCP) and to provide target protein evidence for exploring the mechanisms of the delayed neurotoxicology (OPIDN) induced by organophosphorus compounds (OPs).

METHODSForty two Roman hens were randomly divided into three groups, i.e. TOCP group treated with 1000 mg/kg TOCP; intervention group treated with 40 mg/kg phenylmethanesulfonyl fluoride (PMSF) before 1000 mg/kg TOCP treatment and control group treated with tap water. Four hens in each group were sacrificed on the 5th and 20th days after exposure, respectively. Spinal cords were separated and homogenates at low temperature, and the total proteins were extracted. The OPIDN symptoms observed and recorded in the remaining 6 hens in each group. The differently expressed proteins related to regulating the depolymerization of microtubules were screen by two-dimensional electrophoresis and mass spectroscopy (MS).

RESULTSThe OPIDN symptoms appeared on the 5th day after exposure in TOCP group, which were gradually serious with time. The results by two-dimensional electrophoresis and MS showed that the Stathmin expression was downregulated 3.4 times and 2.8 times in TOCP group, respectively, as compared with the control and PMSF intervention groups. However, there was no significant difference of the Stathmin expression between control group and PMSF intervention group.

CONCLUSIONThe Stathmin expression in the spinal cord tissues of hens exposed to TOCP significantly downregulated. Moreover, the downregulated Stathmin expression may be related to excess polymerization of microtubules and the mechanism of OPIDN.

Animals ; Chickens ; Environmental Exposure ; Female ; Spinal Cord ; metabolism ; Stathmin ; metabolism ; Tritolyl Phosphates ; toxicity

Neuropeptide Y (NPY) is one of the most important orexigenic agents in central regulation of feeding behavior, body weight and energy homeostasis in domestic chickens. To examine differences in the hypothalamic NPY between layer-type and meat-type of chickens, which are two divergent kinds of the domestic chickens in feeding behavior and body weight, we detected mRNA levels of NPY in hypothalamic infundibular nucleus (IN), paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) of these two types of chickens using one-step real time RT-PCR. The meat-type chicken had more food daily (about 1.7 folds) and greater body weights (about 1.5 folds) and brain weights than the layer-type chicken at the age of 14 d. In the meat-type of chicken, NPY mRNA levels of the IN and PVN were significantly greater than those of the LHA, and were not significantly different between the IN and PVN. However, in the layer-type of chicken, NPY mRNA levels were significantly greater in the IN than those in the LHA and PVN, and were not significantly different between the PVN and LHA. In all these hypothalamic regions, the layer-type of chicken had significantly higher NPY mRNA levels than the meat-type chicken did. These results suggest the expression of NPY in the hypothalamus has a type-dependent pattern in domestic chickens.
Animals ; Body Weight ; Chickens ; classification ; metabolism ; Hypothalamus ; metabolism ; Male ; Meat ; Neuropeptide Y ; genetics ; RNA, Messenger ; analysis

The purpose of the present study was to examine the kinetic process of hemoglobin (Hb) carrying and releasing oxygen. Under the standard conditions (pH 7.4, Po(2) 20 mmHg, 20 °C) the blood samples of chicken, rabbit, frog and carp were equilibrated in oxygen content analyzer with calibrated gas mixture A (0.5% CO(2) and 99.5% N(2)). Then the blood samples were exposed to gas mixture B (21% O(2), 0.5% CO(2) and 78.5% N(2)). After equilibration, the blood samples were exposed to gas mixture A again. During the whole process, Po(2) of blood samples was detected in real-time. The time spent in blood Po(2) changing from 0 to 21 kPa was recorded carefully. The results indicated that the kinetic curve of Hb carrying oxygen presented a shape of "S". It was similar to the Hb oxygen dissociation curve (Hb ODC). Based on the curve, T(50), a new kinetic parameter, was established. T(50) is the time of 50% O(2) saturation of Hb. It can reflect the efficiency of Hb carrying oxygen. Through comparing of T(50), the efficiency of Hb carrying oxygen among 4 species of animals was: frog < carp < rabbit < chicken. In the phase I of Hb carrying and releasing oxygen kinetic curve, the slope in carp was much larger than that in rabbit; the time [(1 411±6) s] of Hb releasing oxygen in chicken was longer than that in other 3 animals. These differences reflected the variety of efficiency of Hb carrying and releasing oxygen. In addition, the kinetic features of Hb carrying oxygen were likely to become an important index to evaluate the function of Hb carrying oxygen, especially in evaluating the ability of artificial blood substitute. On the basis of the analysis of the kinetic curve of Hb carrying oxygen and Hb ODC, another new important efficacy parameter E(50) was proposed. E(50) reflects the relationship between the time of 50% O(2) saturation of Hb and environmental Po(2). E(50) can be used as a synthetic index to assess the efficiency of Hb carrying oxygen.
Animals ; Anura ; Carps ; Chickens ; Hemoglobins ; metabolism ; Hydrogen-Ion Concentration ; Kinetics ; Oxygen ; metabolism ; Rabbits

Overexpression of Krüppel like factor 2 (Klf2) or Klf7 inhibits adipocyte formation. However, it remains unclear whether Klf2 regulates klf7 expression in adipose tissue. In this study, oil red O staining and Western blotting were employed to study the effect of Klf2 overexpression on the differentiation of chicken preadipocytes. The results showed that Klf2 overexpression inhibited the differentiation of chicken preadipocytes induced by oleate and the expression of pparγ, while promoted klf7 expression in chicken preadipocytes. Spearman correlation analysis was used to study the correlation between the expression data of klf2 and klf7 in the adipose tissue of both human and chicken. The results showed that there was a significantly positive correlation between the expression of klf2 and klf7 in adipose tissues (r > 0.1). Luciferase reporter assay showed that overexpression of Klf2 significantly promoted the activity of chicken klf7 promoter (-241/-91, -521/-91, -1 845/-91, -2 286/-91, -1 215/-91; P < 0.05). In addition, the activity of klf7 promoter (-241/-91) reporter in chicken preadipocytes was significantly positively correlated with the amount of klf2 overexpression plasmid transfected (T_au=0.917 66, P=1.074×10^-7). Moreover, Klf2 overexpression significantly promoted the mRNA expression of klf7 in chicken preadipocytes (P < 0.05). In conclusion, upregulation of klf7 expression might be one of the pathways that Klf2 inhibits chicken adipocyte differentiation, and the sequence from -241 bp to -91 bp upstream chicken klf7 translation start site might mediate the regulation of Klf2 on klf7 transcription.
Animals ; Humans ; Chickens/genetics* ; Kruppel-Like Transcription Factors/metabolism* ; Transcription Factors/metabolism* ; Adipocytes/metabolism* ; Adipose Tissue/metabolism*

cDNA microarray containing 9024 cDNAs was used to construct gene expression profile in order to screen differentially expressed genes of adipose tissue between broiler and Bai' er and investigate the molecular mechanism related with body fatness traits between the two breeds. Sixty seven differentially expressed genes, being involved in fat metabolism, energy metabolism, cytoskeleton, transcription and splicing factor, protein synthesis and degradation, were screened out. Furthermore, some genes that had no annotation in GenBank were screened out, they were presumed to be unknown new genes. The roles that they may play in chicken fat metabolism need clarify later.
Adipose Tissue ; metabolism ; Animals ; Chickens ; classification ; genetics ; metabolism ; Gene Expression Profiling ; methods ; Lipid Metabolism ; genetics ; Oligonucleotide Array Sequence Analysis

To clone and express the gene encoding chicken aminopeptidase N (chAPN), and analysis the biological function of chAPN expressed in Escherichia coli (E. coli). The chAPN gene was amplified by RT-PCR from the kidney cells of chicken embryo and then cloned into the prokaryotic expression vector pCOLD-TF. Recombinant expression plasmid of pCOLD-TF-chAPN was constructed and then transformed into the competent E. coli BL21(DE3) cells for expression under different conditions such as induction time and inductor concentrations. Purified soluble recombinant chAPN was obtained by Ni-NTA His Bind Resin affinity chromatography and identified by SDS-PAGE gel and Western blotting assay. Its biological function was detected by its reaction with Leu-PNA and Enzyme-Linked Immunosorbent Assay (ELISA). The results showed that the expression product of chAPN gene in E. coli was soluble. It was able to bind infectious bronchitis virus (IBV) dose-dependently. In conclusion, chAPN gene has been successfully cloned and expressed in E. coli, which will establish a basis for further research the enzymatic activity and antiviral function.
Animals ; CD13 Antigens ; biosynthesis ; genetics ; metabolism ; Chickens ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism

OBJECTIVETo investigate the dynamic changes of alpha-tubulin, beta-tubulin and beta-actin in sciatic nerve of hen with organophosphorus ester-induced delayed neuropathy (OPIDN).

METHODSOPIDN was induced in 10-month-old Roman hens by daily subcutaneous administration of 30 mg/kg methamidophos for 15 days. Hens were sacrificed 2, 10, and 23 days respectively after manifesting neuropathy. The sciatic nerves were dissected, homogenized and used for the determination of the alpha-tubulin, beta-tubulin and beta-actin levels by western blotting.

RESULTSThe levels of alpha-tubulin in supernatant of sciatic nerves were decreased by 6%, 15% and 25% respectively on day 2, 10 and 23 respectively, while those in pellet remained almost unchanged. beta-tubulin were decreased by 27%, 6%, 19% in pellet and 1%, 21%, 22% in supernatant of sciatic nerves on 2, 10 and 23 days. Beta-actin level in pellet of sciatic nerve increased by 24%, 48% and 17% on day 2, 10 and 23, and little changes were observed in supernatant.

CONCLUSIONMethamidophos may induced changes of alpha-tubulin, beta-tubulin and beta-actin levels in sciatic nerve of hen, which may be one of the mechanism of the contribution to the occurrence and development of OPIDN.

Actins ; metabolism ; Animals ; Chickens ; Female ; Insecticides ; toxicity ; Organothiophosphorus Compounds ; toxicity ; Sciatic Nerve ; drug effects ; metabolism ; Tubulin ; metabolism

OBJECTIVETo develop the organophosphate-induced delayed neuropathy (OPIDN) hen model with 2,4,6-trimethylbenzoyl phenylphosphonate (TOCP), and observe the change of pathology and investigate the alterations of microtubulin associated protein 2 (MAP2).

METHODS48 adult hens were randomly divided into four groups, including three experimental groups and control group (n = 12 each group). The hens in three experimental groups were treated with TOCP by gavage at single dosages of 250, 500 and 750 mg/kg respectively while the control hens received an equivalent volume of corn oil by gavage. All hens were sacrificed after 21 days of treatment. Half hens in each group were dissected for HE examination and myelin straining of brain, spinal cord and sciatic nerve while brains of another half hens were dissected for the determination of MAP2 by western blotting.

RESULTSThe delayed neurotoxicity symptoms of hens both in 500 and 750 mg/kg groups were consistently observed. The pathological changes of brain, spinal cord and sciatic nerve in 500 and 750 mg/kg groups showed nerve cells difference necrosis, increased cytoplasm basophilia, microglia proliferation, mono-nuclear and lymphocyte infiltration, myelin sheath extensive up to part of them disaggregation deletion. Compared with the control group, at 500 and 750 mg/kg respectively the increase of MAP2 was 25% and 23% (P < 0.01 and P < 0.05).

CONCLUSIONSThe histopathologic changes of OPIDN caused by TOCP have dose-response relationship. The changes of MAP2 in nervous system may contribute to the occurrence and development of TOCP induced delayed neurotoxicity.

Animals ; Brain ; metabolism ; pathology ; Chickens ; Female ; Microtubule-Associated Proteins ; metabolism ; Nervous System Diseases ; chemically induced ; metabolism ; pathology ; Organophosphates ; toxicity