Polymorphisms in the 5 ′ regulatory region of my-ostatin gene are associated with early growth traits in Yorkshire pigs

Myostatin is a negative regulator of skeletal muscle mass. The present study cloned the 5′ regulatory region of porcine myostatin gene, screened its polymorphisms and analyzed their associations with early growth traits in Yorkshire pigs. The results indicated that a fragment length polymorphism and a polymorphism concerning two nucleotide changes exist in the 5′ regulatory region of porcine my-ostatin gene. At sites 435 and 447, allele A and allele B have the haplotypes of A-G and G-A, respec-tively. The allelic frequency of B is 0.475 in Yorkshire pigs. No homozygous BB genotype was detected in 9 Laiwu Black pigs. Allele B was found to have positive effect on body weight on day 21 (BW21) (P<0.01), body weight on day 28 (BW28) (P<0.05), body weight on day 70 (BW70) (P<0.05), average daily gain from birth to 21 d (ADG1) (P<0.01), average daily gain from birth to 28 d (ADG2) (P<0.05) and av-erage daily gain from 21 d to 70 d (ADG3) (P<0.01), respectively. The additive effect of allele B on BW21, BW28, BW70, ADG1, ADG2 and ADG3 was 0.596±0.205 kg (P=0.0041), 0.498±0.200 kg (P=0.0136), 1.409±0.551 kg (P=0.0112), 28.39±9.74 g P=0.0041), 17.78±7.15 g (P=0.0136) and 37.00±16.92 g (P=0.0304), respectively, whereas its effect on average daily gain from 28 d to 70 d (ADG4) was not significant (P>0.1), although BB individuals are superior in average daily gain to AA and AB.     

猪肌肉生长抑制素基因5′调控区T→A突变与生长性状的关系分析

生长速度是猪育种中选择的主要目标性状之一,鉴定影响生长速度的QTL或基因具有重要的实践意义和理论价值.对猪肌肉生长抑制素基因(myostatin,MSTN)5′调控区TA突变与生长性状的关系进行了分析.突变所产生的基因型的判定采用PCR-RFLP方法进行.猪生长性状的测定指标包括60日龄体重(body weight at 60d,BW60)、前期平均日增重(average daily gain of stage one,ADG1)、后期平均日增重(average daily gain of stage two,ADG2)和全期平均日增重(average daily gain of whole stage,ADG),所采用的记录数分别来自165,276,275和275头无亲缘关系个体.采用SAS软件包的GLM程序对MSTN基因型与猪生长性状的关系进行分析.结果表明,MSTN基因型对猪BW60,ADG1和ADG2的效应不显著(P＞0.1),对ADG2的效应在剔除基因型与品种的互作效应以后几乎达到显著水平(P＝0.0522),突变等位基因的携带者(基因型为TA)具有较高的后期平均日增重.     

猪肌肉生长抑制素基因5‘调控区T→A突变与生长性状的关系分析

生长速度是猪育种中选择的主要目标性状之一,鉴定影响生长速度的QTL或基因具有重要的实践意义和理论价值。对猪肌肉生长抑制素基因（myostatin,MSTN)5‘调控区T→A突变与生长性状的关系进行了分析。突变所产生的基因型的判定采用PCR－RFLP方法进行。猪生长性状的测定指标包括60日龄体重（body weight at 60d,BW60)、前期平均日增重（average daily gain of stage one,ADG1)、后期平均日增重（average daily gain of stage two,ADG2)和全期平均日增重（average daily gain of whole stage,ADG),所采用的记录数分别来自165．276,275和275头无亲缘关系个体。采用SAS软件包的GLM程序对MSTN基因型与猪生长性状的关系进行分析。结果表明,MSTN基因型对猪BW60（P＝0．0522）,突变等位基因的携带者（基因型为TA）具有较高的后期平均日增重。     

Metabolic characteristics and nutrient utilization in high-feed-efficiency pigs selected using different feed conversion ratio models

An understanding of the nutrient utilization characteristics of pigs with different feed efficiencies(FEs) will help us to develop new strategies to reduce the costs of pig production. In this study, we selected pigs with a range of FEs according to two feed conversion ratio models: the feed intake(FI) model, where pigs had the same average daily gains(ADGs) but different FIs, and the ADG model, where pigs had the same FIs but different ADGs. High-FE pigs had a higher abundance of short chain fatty acid(SCFA)-producing bacteria(Lachnospiraceae, Clostridiaceae_1, and Coriobacteriaceae) in their caecum in the FI model, and low-FE pigs had a higher abundance of two families(Bacteroidales_S24_7_group and Peptococcaceae) and two genera(Anaerotruncus and Candidatus_Soleaferrea) in both models. By contrast, high-FE pigs had more goblet cells and higher m RNA expression of insulin-like growth factor 1(IGF-1) in the FI model, and higher mRNA expression of occludin but lower expressions of adenosine monophosphate-activated protein kinase(AMPK)-α2 and peroxisome proliferator-activated receptor gamma coactivator 1 alpha(PGC1α) in the ADG model. These findings suggest that the presence of SCFA-producing bacteria in the caecum and increased muscular growth may contribute to the high FE of low-FI pigs, while improved intestinal functions and decreased mitochondrial activity in the skeletal muscle are related to the high FE of high-ADG pigs.     

Effect of hormonal status and metabolic changes of restricted ewes during late pregnancy on their fetal growth and development

This study investigated the effects of hormonal status and metabolic changes of restricted ewes during late pregnancy on the ovine fetus growth and development. One hundred Mongolian ewes, synchro- nized for oestrus and mated, were divided into three groups and offered 0.175 MJME·kgw-0.75·d-1 (Re- stricted Group 1, RG1), 0.33 MJME·kgw-0.75·d-1 (Restricted Group 2, RG2) and ad libitum access to feed (Control Group, CG) during their late pregnancy respectively. The results suggested that with the sup- ply of exogenous energy decreasing during late pregnancy, maternal body weight and net body weight loss in RG2 and RG1 were lower than those of CG (P<0.01). The insulin and IGF-1 concentrations of ewes in RG2 and RG1 tended to be lower than those of CG (P>0.05), but the GH concentrations in RG2 and RG1 were enhanced and there was significant difference between RG1 and CG on d 120 of gesta- tion (P<0.05). The glucose concentration of ewes in RG2 and RG1 was decreased throughout the feed restriction period, and the differences were observed between RG1 and CG on d 120 of gestation (P<0.05). In addition, the nonesterified fatty acid (NEFA) and total amino acid (TAA) concentrations of ewes in RG2 tended to increase, but there was no significant difference (P>0.05). However, the NEFA and FAA concentrations of ewes in RG1 were reduced from d 90 to d 120 of gestation, then enhanced from d 120 to d 140 of gestation. During the late pregnancy, with the supply of nutrition decreasing, the negatively physiological and biochemical maternal reactions to restriction became worse, which sig- nificantly reduced the average lamb birth weight and daily growth rate of fetus in RG2 (P<0.05) and RG1 (P<0.01).     

Effect of recombinant growth hormone on expression of growth hormone receptor, insulin-like growth factor mRNA and serum level of leptin in growing pigs

Growth hormone (GH) plays an important role in regulation of animal growth, metabolism and lactation[1]. Numerous studies have shown that exogenous somatotropin (ST) can increase average daily weight gain, improve feed efficiency, stimulate protein deposition and muscle growth and decrease lipid accretion rate[1]. The original somatomedin hypothesis suggested that the effect of GH on postnatal growth was mediated by insulin-like growth hormone factor 1 (IGF-I) which was thought to be deriv…     

Offspring diet supersedes the transgenerational effects of parental diet in a specialist herbivore Neolema abbreviata under manipulated foliar nitrogen variability

Diet quality influences organismal fitness within and across generations.For herbivorous insects,the transgenerational effecets of diet remain relatively underexplored.Usinga3×3×2 factorial experiment,we evaluated how N enrichment in parental diets of Neolemd abbreviata(Larcordaire)(C oleoptera:Chrysomelidae),a biological control agent for Tradescantia fluminensis Vell.(Commelinaceae),may influence life history and performance of Fi and F2 offspring under reciprocal experiments.We found limited transgenerational effects of foliar nitrogen variability among life-history traits in both larvae and adults.Larval weight gain and mortality were responsive to parental diet contrary to feeding damage,pupal weight and duration taken to pupate.There were significant parental diet x test interactions in larval feeding damage,weight gain,pupal weight and time to pupation.Generally,offspring from parents under high N plants performed better even under low N test plants.Adult traits including oviposition selection,feeding weight and longevity did not respond to the efects of parental diet nor its interaction with test diet as was the case in the larval stage.However,the main efects of test diet were more important in determining adult performance in both generations suggesting limited sensitivity to parental diet in the adult stage.Our results show conflicting responses to parental diet between larvae and adults ofthe same generation among an insec species with both actively feeding larual and adult life stagee These tranegeneratinonal efferte,or lack thereof,may have implications on the field performance of N.abbrevita under heterogencous nutritional landscapes.     

Histochemical study of the pre—and postnatal development of acetylcholinesterase in the rat spinal cord

The distribution of acetylcholinesterase(AChE)-positive structures in the developing rat spinal cord was studied with AChE-histochemistry.AChE-positive perikarya were first seen on embryonic day 14(E14) in the ventrolateral portion of the spinal cord.From that time onward.AChE=containing cells appeared gradually in the intermediate gray,dorsal horn and lateral spinal nucleus of the spinal cord in a ventral-to-dorsal,and lateral-to-medial order.No obvious rostral-to-caudal sequence was found.At birth,the distribution pattern of AChE-positive perikarya was basically similar to that in adults.After birth a dramatic increase in the AChE staining intensity extended from postnatal day 5(P5) to postnatal day 21(P21),In addition,two phases of transient AChE staining were observed in the external surface of the dorsal horn from embryonic day 15(E15) to embryonic day 21(E21) and in the marginal layer from embryonic day 21(E21) to postnatal day 14(P14),respectively.     

Production of endothelial nitric oxide synthase (eNOS) over-expressing piglets

Vascular function, vascular structure, and homeostasis are thought to be regulated in part by nitric oxide (NO) released by endothelial cell nitric oxide synthase (eNOS), and NO released by eNOS plays an important role in modulating metabolism of skeletal and cardiac muscle in health and disease. The pig is an optimal model for human diseases because of the large number of important similarities between the genomic, metabolic and cardiovascular systems of pigs and humans. To gain a better understanding of cardiovascular regulation by eNOS we produced pigs carrying an endogenous eNOS gene driven by a Tie-2 promoter and tagged with a V5 His tag. Nuclear transfer was conducted to create these animals and the effects of two different oocyte activation treatments and two different culture systems were examined. Donor cells were electrically fused to the recipient oocytes. Electrical fusion/activation (1 mM calcium in mannitol: Treatment 1) and electrical fusion (0.1 mM calcium in mannitol)/chemical activation (200 μM Thimerosal for 10 min followed by 8 mM DTT for 30 min: Treatment 2) were used. Embryos were surgically transferred to the oviducts of gilts that exhibited estrus on the day of fusion or the day of transfer. Two cloned transgenic piglets were born from Treatment 1 and low oxygen, and another two from Treatment 2 and normal oxygen. PCR, RT-PCR, Western blotting and immunohistochemistry confirmed that the pigs were transgenic, made message, made the fusion protein and that the fusion protein localized to the endothelial cells of placental vasculature from the conceptuses as did the endogenous eNOS. Thus both activation conditions and culture systems are compatible with development to term. These pigs will serve as the founders for a colony of miniature pigs that will help to elucidate the function of eNOS in regulating muscle metabolism and the cardiorespiratory system.     

Insulin requirement profiles and related factors of insulin pump therapy in patients with type 2 diabetes

Continuous subcutaneous insulin infusion(CSII) is an effective therapy to control hyperglycemia in both patients with type 1 diabetes and type 2 diabetes.However,there is little data investigating the insulin dose setting during CSII therapy in type 2 diabetes to achieve optimal glycemic control and avoid the risk of hypoglycemia.Thus,this study is aimed to assess the dose characteristics of insulin requirement and explore the related clinical factors in patients with type 2 diabetes who were treated with CSII.A total of 327 patients(195 males) aged 52.9±12.5 years old were included in this study.Patients were treated with CSII to achieve the target fasting capillary blood glucose(4.4-7.0 mmol L ~(-1)) and 2-h postprandial capillary blood glucose(4.4-10.0 mmol L ~(-1)) by adjusting insulin infusion according to the seven-point capillary blood glucose profiles.Total daily insulin dose(TDD),total daily insulin dose per kilogram(TDD kg-1) and the ratio of total basal insulin dose(TBD) to TDD(%TBa) were calculated after patients achieved the glucose targets for at least 3 days via 1-2 weeks of CSII treatment.And insulin dose,insulin dosing patterns and the relevant clinical factors were analyzed.The mean ratio of basal/bolus insulin distribution of all patients was 40%:60%.Patients with central obesity needed more TDD(51.3±17.1 U versus 43.5±14.0 U,P0.05) and TDD kg ~(-1)(0.8±0.3 U kg ~(-1) versus 0.7±0.2 U kg ~(-1),P0.05) than those without central obesity.Pearson's correlation analysis demonstrated that TDD was positively correlated with body mass index(BMI),waist circumference(WC),baseline fasting plasma glucose(FPG),fasting C-peptide level,2 h-postprandial C-peptide level and time to achieve glycemic target(all P0.05);TDD kg ~(-1) was positively correlated with waist-to-hip ratio(WHR),baseline FPG,glycosylated hemoglobin Ale(HbAlc),fasting C-peptide level and time to achieve glycemic target,and negatively correlated with BMI(all P0.05).Multiple linear regression analyses revealed that BMI(β=1.796,P0.01),WC(β=0.109,P0.01),baseline FPG(β=1.459,P0.01) and HbAlc(β=0.930,P=0.021) were independently related to TDD.Gender(β=-0.107,P=0.003),WC(β=0.005,P=0.029),baseline FPG(β=0.025,P0.01) and HbAlc(β=0.016,β=0.007) were independently associated with TDD kg ~(-1).Gender(β=-0.015,P=0.048) and disease duration(β=0.134,P=0.029) were independently associated with %TBa.%TBa is around 40% in Chinese patients with type 2 diabetes treated with CSII when glycemic control is achieved.In addition to body weight or BMI,WC and glucose levels before CSII should be considered to set TDD.Patients with central obesity or poor glycemic control might need more TDD.Higher %TBa should be considered in female patients or patients with longer disease duration.     

Responding to the weather:energy budgeting by a small mammal in the wild

Energy conservation is paramount for small mammals because of their small size,large surface area to volume ratio,and the resultant high heat loss to the environment.To survive on limited food resources and to fuel their expensive metabolism during activity,many small mammals employ daily torpor to reduce energy expenditure during the rest phase.We hypothesized that a small terrestrial semelparous marsupial,the brown antechinus Antechinus stuartii,would maximize activity when foraging conditions were favorable to gain fat reserves before their intense breeding period,but would increase torpor use when conditions were poor to conserve these fat reserves.Female antechinus were trapped and implanted with small temperature-sensitive radio transmitters to record body temperature and to quantify torpor expression and activity patterns in the wild.Most antechinus used torpor at least once per day over the entire study period.Total daily torpor use increased and mean daily body temperature decreased significantly with a reduction in minimum ambient temperature.Interestingly,antechinus employed less torpor on days with more rain and decreasing barometric pressure.In contrast to torpor expression,activity was directly related to ambient temperature and inversely related to barometric pressure.Our results reveal that antechinus use a flexible combination of physiology and behavior that can be adjusted to manage their energy budget according to weather variables.     

Stock dynamics of Cleisthenes herzensteini in the central and southern Yellow Sea

Anthropogenic activities and environmental changes have had a significant effect on the fishery ecosystem, biological characteristics, and population dynamics of marine fishes. Overfishing threatens the sustainability of many populations. We evaluated changes in the biological characteristics, distribution, and abundance of Cleisthenes herzensteini using bottom trawl survey data collected from 1985 to 2010 in the central and southern Yellow Sea. The dominant body length of C. herzensteini during spring was 80–160 mm in 1986, 60–160 mm in 1998, and 41–80 mm and 111–170 mm in 2010. During summer, the dominant body length was 80–180 mm and 130–169 mm in 2000 and 2007, respectively. During autumn, the dominant body length was 60–160 mm, 100–180 mm, and 90–149 mm in 1985, 2000, and 2009, respectively. During winter, the dominant body length was 80–200 mm, 120–220 mm, and 100–200 mm in 1985, 1999, and 2010, respectively. The dominant body length decreased gradually from 1985 to 2010 (excluding spring, 2010), illustrating the “miniaturization” of the C. herzensteini population. Growth was significantly different between male and female individuals, with male individuals forming a “smaller-size type”. The sex ratio of C. herzensteini was relatively stable during spring and summer, but significantly different during autumn and winter. The diet of C. herzensteini also changed significantly from 1985 to 2010. During 1985–1986, the diet consisted primarily of Crangon affinis, Eualus sinensis and Gammaridae species. C. affinis, Engraulis japonicus, and Ammodytes personatus were dominant during 1998–2000, whereas C. affinis was the dominant prey species during 2009–2010. Thus, there was a clear decrease in dietary diversity, with a shift to benthos shrimp, particularly C. affinis, which accounted for 82.58% of the total diet (by weight) in 2010. The gastric vacuous rate also decreased in every season and the gonad developmental stage changed with each season. The distribution of C. herzensteini shifted northward and offshore and became more concentrated. The average catch per haul of C. herzensteini decreased in spring and autumn. The average catch per haul ranged from 1.44 kg h^-1 to 0.14 kg h^-1 in spring and the percentage by weight ranged from 6.53% to 1.28%. The average catch per haul ranged from 3.03 kg h^-1 to 0.26 kg h^-1 in autumn and the percentage by weight ranged from 8.00% to 0.60%. The average catch per haul increased significantly during summer, ranging from 0.18 kg h^-1 to 0.58 kg h^-1, with a percentage by weight of 0.03–0.80%. The average catch per haul was relatively stable in winter (around 1.00 kg h^-1), but the percentage by weight gradually increased during 1985–2010. Taken together, our results suggested that the population structure, diet composition, and distribution of C. herzensteini had been altered during the last three decades. To address this, it is essential to initiate measures to conserve the C. herzensteini resource.     

Effect of the Yellow Sea Cold Water Mass (YSCWM) on distribution of bacterioplankton

Four surveys were carried out in August 2001, and in August, September and October 2002 in the southern Yellow Sea, China. Bacterioplankton abundance and biomass were quantified along the transects from Qingdao, China to the Korean island of Jeju. In this paper, the author describes the distribution of bacterioplankton and predatory pressures, and also discusses the impact of Yellow Sea Cold Water Mass (YSCWM) on the distribution of bacterioplankton. The range of Synechococcus biomass was 0.78–33.49 mg C/m³ (on average 6.26 mg C/m³), and heterotrophic bacteria biomass was 1.58–21.25 mg C/m³ (on average 5.79 mg C/m³, n=197). In the vertical direction, the distribution order of Synechococcus biomass was mid-layer>surface>bottom, and the one of heterotrophic bacteria biomass was surface>mid-layer>bottom. The contribution of Synechococcus to the total phytoplankton biomass (SB/PB) ranged from 2% to 99% (on average 42.5%), and the ratio of heterotrophic bacterial biomass to phytoplankton biomass (HBB/PB) was from 5% to 637% (on average 85%). Daily variations of bacterioplankton biomass at anchor stations showed that the maximal Synechococcus biomass was 8.8 times the minimum, and it was 2.8 times in heterotrophic bacterial biomass. The distribution of bacterioplankton accorded with temperature and salinity, and the minimum of bacterioplankton biomass occurred in the YSCWM waters. At the same time, the microzooplankton (20–200 μm) preyed on Synechococcus in these waters, with the ingestion rate of about 0.20–0.42/d.     

Effect of food restriction on the energy metabolism of the Chinese bulbul (Pycnonotus sinensis)

Food resources play an important role in the regulation of animals’ physiology and behavior. We investigated the effect of short-term food restriction on metabolic thermogenesis of Chinese bulbuls(Pycnonotus sinensis) by measuring changes in body mass, body fat, basic metabolic rate(BMR), and organ mass of wild-caught Chinese bulbuls from Wenzhou, China. Short-term food restriction induced a significant decrease in body mass and body fat but body mass returned to normal levels soon after food was no longer restricted. Food restriction caused a significant reduction in BMR after 7 days(P<0.05), which returned to normal levels after food restriction ceased. Log total BMR was positively correlated with log body mass(r2=0.126, P<0.05). The dry masses of livers and the digestive tract were higher in birds that had been subject to temporary food restriction than in control birds and those subject to continual food restriction(P<0.001 and P<0.05, respectively). There was also significant differences in the dry mass of the lungs(P<0.05), heart(P<0.01), and spleen(P<0.05) in birds subject to short-term food restriction compared to control birds and those subject to continual food restriction. BMR was positively correlated with body and organ(heart, kidney and stomach) mass. These results suggest that the Chinese bulbul adjusts to restricted food availability by utilizing its energy reserves, lowering its BMR and changing the weight of various internal organs so as to balance total energy requirements. These may all be survival strategies that allow birds to cope with unpredictable variation in food abundance.     

Effects of the monoclonal antibody against porcine 40 kDa adipocyte-specific plasma membrane protein on adipocytes and carcass composition

The effects of the mouse monoclonal antibody against 40 kDa adipocyte-specific plasma membrane protein on porcine adipocytes and carcass composition were investigated in vitro and in vivo. Results revealed that the in vitro complement-mediated cytotoxicity of this monoclonal antibody can lead to adipocyte lysis, remarkable reduction of adipocyte lipid accumulation （P〈0.01）, and significant decrease of well-differentiated fat cells （P〈0.01）. Treatment of adipocytes with this antibody alone in vitro did not induce cell lysis, but could lead to noticeable reduction of well-differentiated cells and lipid accumulation （P〈0.05） at the pre-adipocyte stage. In vivo, pigs injected with 0.5 mg/kg or 1.0 mg/kg of antibody showed smaller adipocyte sizes （P〈0.01） and reduced lipid accumulation of adipocytes （P〈0.01）. Our results also indicated that pigs intraperitoneally or subcutaneously immunized with 0.5 mg/kg of monoclonal antibody at 15 kg or 1.0 mg/kg antibody at 60 kg had a higher lean meat percentage （P〈0.05）, larger loin eye area （P〈0.05）, lower fat meat percentage （P〈0.05）, less backfat thickness （P〈0.05） and smaller leaf fat weight （P〈0.05） than the control pigs, but other carcass traits such as caul fat weight, heart weight, liver weight, spleen weight, kidney weight, lung weight, and dressing percentage were not significantly affected. These results suggested that this monoclonal antibody could be applied to restrain excessive fat deposition in porcine production.     

Bioavailability and possible benefits of wheat intake naturally enriched with selenium and its products

Bioavailability and possible benefits of wheat intake naturally enriched with selenium and its products was tested. Wheat obtained by application of an original combination and procedure for foliar supplementation of plants with Se was characterized on the average by five times higher content of Se, the main form being l-(+)-selenomethionine (SeMet). Substitution of Se-deficient wheat by wheat naturally enriched with Se and its products contributed to the increase of daily intake on the average by 18 μg (12–35 μg) in volunteers, which is more than 50% of the average daily intake. Six weeks after the beginning of its application, increased daily intake of Se brought about the increase of its concentration in the plasma of the examined persons by 53%, in their erythrocytes by 37%, in their hair by 44%, and in their urine by 54%. This result was comparable to the effect obtained in the course of an 8-wk daily intake of supplements with 100 μg Se in the form of enriched bakery yeast. Analysis of glutathione peroxidase (GSH-Px) activity in blood, thiobarbituric acid reactive substances (TBARS) in plasma, lipid parameters (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides), and glucose in serum of volunteers showed that the increased Se intake induced increased GSH-Px activity in blood and decreased concentrations of TBARS, lipid parameters, and glucose in blood. Using only one crop (wheat enriched with Se), the existing deficiency of Se in our population can be alleviated. In this way, one-fourth of our population with lower Se intake than 21 μg/d will satisfy basal requirements, whereas one-half will become moderately deficient in Se instead of distinctly deficient in Se.     

Porcine growth differentiation factor 9 gene polymorphisms and their associations with litter size

Growth differentiation factor 9 (GDF9) is expressed in oocytes and is thought to be required for ovarian folliculogenesis.Given this function,GDF9 may be considered as a candidate gene controlling pig ovulate rate.In this study,the complete coding sequence was cloned (encoding a 444 amino acid),intron sequence and partial 5'-UTR of pig GDF9.RT-PCR results showed that GDF9 mRNA is expressed in a wide range of tissues of the ruttish Erhualian pig.The expression levels of GDF9 mRNA in pituitary,ovary,uterus and oviduct are higher in the Erhualian pigs than those in Duroc pigs,especially in pituitary with a significant difference (P＜0.05).Comparative sequencing revealed 12 polymorphisms,including 8 single nucleotide polymorphisms (SNPS) and one 314 bp indel in noncoding regions,and the other 3 SNPS in coding regions.Four polymorphisms,G359C,C1801T,T1806C and 314 bp indel,were developed as markers for further use in population variation and association studies.The G359C polymorphism segregates only in Chinese native pigs,Erhualian and Dahuabai,on the contrary,314 bp indel segregates only in Duroc and Landrace.C1801T and T1806C sites seem to be completely linked and segregate in Erhualian,Dahuabai and Landrace.In a word,GDF9 may be not associated with pig litter size in extensive populations as per the studies of allele distributions of the four polymorphisms and pilot association in four breeds.     

Effects of Feeding Time on the Growth Performance and Variation of RNA/DNA Ratio of the Chinese Soft-shelled Turtle,Pelodiscus sinensis

The present study was to investigate the effects of feeding time on growth of the Chinese soft-shelled turtle. The experiment was carried out with a photoperiod of 12L(light):12D(dark) with lights on at 06:00 and off at 18:00. Turtles were maintained at a temperature of 32 ± 0.2 °C in tanks throughout the length of the experiment. The turtles in group 1 to group 6 were fed respectively at 00:00, 04:00, 08:00, 12:00, 16:00 and 20:00 with 60 turtles each(Initial body weight 88.27 ± 0.09 g). Acrophases of postprandial RNA/DNA ratio in liver in each group was shown between 5h and 7h after feeding. A positive linear correlation could be seen between specific growth rate(SGR) and RNA/DNA:SGR=1.1586RNA/DNA–0.7097(r = 0.9328, P = 0.0066). The results indicated that the values at the acrophases of about 6h after feeding might be used as an instantaneous growth index in the Chinese soft-shelled turtle. The turtles in group 1 grew better than group 3, group 4, group 5, group 6, because they ate more, but they ate more and grew slower than group 2, whose feed conversion rate was also higher. Meanwhile, the SGR and feeding rate of turtles fed at 12:00 were the lowest from the six groups(P 0.05). Turtles fed in group 1, group 2 and group 6 developed more heavy final body weight(FBW), higher feeding rate and SGR than the other three groups. This probably suggested that turtles fed in scotophase grew better than that fed at photophase in total.     

The single nucleotide polymorphisms of the chicken myostatin gene are associated with skeletal muscle and adipose growth

Myostatin, a new member of the TGF-p superfamily, is predominantly expressed in skeletal muscle cells and functions as a negative regulator of skeletal muscle growth in animals. Recently, we have reported three single nucleotide polymorphisms (SNPs) in the chicken my-ostatin gene. Herein, we investigate the association of those SNPs with the production traits in a F2 chicken line derived from Broilers crossing to Silky with the least square analysis. The results show that the BB and AA genotypes are strongly associated with abdominal fat weight (AFW), abdominal fat percentage (AFP), and birth weight (BW) (P < 0.05). Breast muscle percentage (BMP) of the AA type is higher than that of the AB type. The breast muscle weight and breast muscle percentages of F2 individuals have significant difference between CC and DD genotypes (P< 0.05). Breast muscle weight (BMW) of EF birds is higher than that of EE birds (P< 0.05). In this report, we present the first genetic evidence to show that chicken myostatin not o