Successful embryo transfer in Tianzhu white yak using standard protocol

The present study was carried out to investigate the efficiency of superovulation, oestrus synchroni-zation, and embryo recovery in Tianzhu white yaks and also to confirm the pregnancy rate of black yaks, to which embryos collected from white yaks were transplanted. Forty-seven yaks were selected from different experiment groups, including 10 Tianzhu white female yaks (donor, group A) and 37 black female yaks (recipient, groups B and C). Superovulation of the donor was induced by the application procedure of CIDR-B FSH PG. Oestrus synchronization of recipients was induced using two meth-ods: group B was given the same treatment as group A, except that the follicle-stimulating hormone (FSH) injection was not administered, whereas group C was injected with cloprostenol only once when corpus luteum (corpora lutea) was (were) palpated. The results showed that the oestrous rates in group A were higher (80%) than those in group B (60%) and group C (44.5%). As for the efficiency of su-perovulation, it was indicated that the mean numbers (±SD) of total corpora lutea, follicles, viable (transferable), and degenerated embryos were 4.75 ± 2.19, 1.13 ± 0.83, 2.50 ± 1.31, and 1.38 ± 0.92, re-spectively. The mean embryo recovery rates were 55.6%. All together, 18 viable embryos of Tianzhu white yak were obtained and 12 of them were transplanted to 10 recipients. The pregnancy rate was 50% and the delivery rate was 40%.     

Simulated biological effects of microgravity on phospholipid and energy metabolism of chicken embryonic brain cells studied by ~(31)P-NMR spectroscopy

Levels of phosphomonoester (PME), phosphodiester (PDE), ATP and pH in brain cells of chicken embryos rotated for 24 h in a clinostat during the period of hatching the 13th day (E13) and 15th day (E15) embryos were investigated by using 31P-NMR spectroscopy. Significant increases in the values of PME, ATP and pH were identified after E13 rotating for 24 h. With the same treatment, differences were obtained in the phospholipid and energy metabolism of E15, but no significant levels have been reached . The calorimetric assay (malachite green method) was used for measuring the activity of total ATPase. A dramatic decrease was evident in the activity of ATPase in brain cells of rotated E13 and E15. The former is more sensitive than the latter. All the levels mentioned above could restore in 24 h after the rotation stopped, except that the level of ATP was still higher than the control.     

Efficient production of transgenic chickens using self-inactive HIV- based lentiviral vectors

We demonstrated the simple and effective production of transgenic chickens, in which the enhanced green fluorescence protein （EGFP） was expressed by using third-generation self-inactive HIV-based lentiviral vectors. In our experiments, lentiviruses were injected into 204 fertilized eggs, from which 30 （15%） chickens were hatched. The exogenous gene was detected in the genomes of 16 out of 30 （53%） chickens. The green fluorescence signal was observed directly in various body parts, and was particularly significant in the testes. The transgenes were also found in the offspring of these chickens. The results indicate that HIV-based lentiviral vectors can be used to generate transgenic birds economically and effectively [ Current Zoology 55 （5）： 383 - 387,2009].     

鸡胚胎干细胞的分离、培养和鉴定

SNL cells (permanent line of irradiated mouse fibroblast cells), primary mice embryonic fibroblasts (PMEF) cells and primary chicken embryonic fibroblasts (PCEF) cells were respectively used as the feeder cells for chicken embryonic stem cell culture. The isolated blastoderm cells front the stage X embryos of chicken were cultured in Dulercco‘‘ s Modified Eagle Medium (DMEM) supplemented with leukemia inhibitory factor (LIF, 1 000 IU/ml), basic fibroblast growth factor (bFGF 10 ng/ml) and stem cell factor (SCF, 5 ng/ml). The alkaline phosphatase (AKP) test, differentiation experiment in vitro and chimeric chicken production were carried out. The resuts showed that culture on feeder layer of PMEF yielded high quality CES cell colonies. The shape of typical CES clone showed as follows: nested aggregation (clone) with clear edge and round surface as well as close arrangement within the clone. Strong positive AKP reactive cellswere observed. On the other hand, the fourth passage CES cells could differentiate into various cells in the absence of feeder layer cells and LIF in vitro. The third and fourth passage cells were injected into the subgerminal cavity of recipient embryos at stage X. The manipulated embryos were incubated until hatching. Of 269 Hailan embryos injected with CES cells of Shouguang Chickens, 8.2 % (22/269) survived to hatching, 3 feather chimeras had been produced, which suggests that an effective culture systems were established and it could promote the growth of CES cells and maintain them in an undifferentiated state .     

Effects of shark hepatic stimulator substance on the function and antioxidant capacity of liver mitochondria in an animal model of acute liver injury

This study was carried out to investigate whether shark hepatic stimulator substance （HSS） can prevent acute liver injury and affect mitochondrial function and antioxidant defenses in a rat model of thioacetamide （TAA）-induced liver injury. The acute liver injury was induced by two intraperitoneal injections of TAA （400 mg/kg） in a 24 h interval. In the TAA plus shark HSS group, rats were treated with shark HSS （80 mg/kg） 1 h prior to each TAA injection. In this group, serum liver enzyme activities were significantly lower than those in the TAA group. The mitochondrial respiratory control ratio was improved, and the mitochondrial respiratory enzyme activities were increased in the TAA plus shark HSS group. The mitochondrial antioxidant enzyme activities and glutathione level were higher in the TAA plus shark HSS group than in the TAA group. These results suggest that the protective effect of shark HSS against TAA-induced acute liver injury may be a result of the restoration of the mitochondrial respiratory function and antioxidant defenses and decreased oxygen stress.     

Treatment of chronical myocardial ischemia by adenovirus-mediated hepatocyte growth factor gene transfer in minipigs

Growth factor gene transfer-induced therapeutic angiogenesis has become a novel approach for the treatment of myocardial ischemia. In order to provide a basis for the clinical application of an adeno- virus with hepatocyte growth factor gene (Ad-HGF) in the treatment of myocardial ischemia, we estab- lished a minipig model of chronically ischemic myocardium in which an Ameroid constrictor was placed around the left circumflex branch of the coronary artery (LCX). A total of 18 minipigs were ran- domly divided into 3 groups: a surgery control group, a model group and an Ad-HGF treatment group implanted with Ameroid constrictor. Ad-HGF or the control agent was injected directly into the ischemic myocardium, and an improvement in heart function and blood supply were evaluated. The results showed that myocardial perfusion remarkably improved in the Ad-HGF group compared with that in both the control and model groups. Four weeks after the treatment, the density of newly formed blood vessels was higher and the number of collateral blood vessels was greater in the Ad-HGF group than in the model group. The area of myocardial ischemia reduced evidently and the left ventricular ejection fraction improved significantly in the Ad-HGF group. These results suggest that HGF gene therapy may become a novel approach in the treatment of chronically ischemic myocardium.     

Heat sensitivity of eggs attributes to the reduction in Agasicles hygrophila population

Agasicles hygrophila has been introduced worldwide as a control agent for the invasive weed Alternanthera philoxeroides.However,global warming has potential impact on its controlling efficacy.The aim of this research was to explore the primary factors responsible for the greatly reduced A.hygrophila population in hot summers.To imitate the temperature conditions in summers,different developmental stages of hygrophila were treated with high temperatures from 32.5℃ to 45℃ for 1-5 h.Based on the survival rate,the heat tolerance of each developmental stage was ranked from lowest to highest as follows:egg,1st,2nd,3rd instar larva,adult and pupa.Eggs showed the lowest heat tolerance with 37.5℃ as the critical temperature affecting larval hatching.Heat treatment of the A.hygrophila eggs at 37.5℃ for 1 h decreased the hatch rate to 24%.Our results indicated that when compared with the control at 25℃,1 h treatment at 37.5℃ prolonged the duration of the egg stage,shortened the duration of oviposition and total longevity,and changed the reproductive pattern of A.hygrophila.The net reproductive rate,intrinsic rate and finite rate were all significantly reduced.The results suggest that low heat tolerance of the eggs was the major factor responsible for the reduction of A.hygrophila populations,and the key temperature was 37.5°C.Therefore,appropriate measures should be taken to protect eggs in order to maintain the efficacy of A.hygrophila in the biological control of A.philoxeroides in hot summers.     

Single nucleotide polymorphisms in chicken lmbr1 gene were associated with chicken growth and carcass traits

Lmbr1 is the key candidate gene controlling vertebrate limb development, but its effects on animal growth and carcass traits have never been reported. In this experiment, lmbr1 was taken as the candi-date gene affecting chicken growth and carcass traits. T/C and G/A mutations located in exon 16 and one A/C mutation located in intron 5 of chicken lmbr1 were detected from Silky, White Plymouth Rock broilers and their F2 crossing chickens by PCR-SSCP and sequencing methods. The analysis of vari-ance (ANOVA) results suggests that T/C polymorphism of exon 16 had significant association with eviscerated yield rate (EYR), gizzard rate (GR), shank and claw rate (SCR) and shank girth (SG); A/C polymorphism of intron 5 was significantly associated with SCR, liver rate and head-neck weight (HNW), while both sites had no significant association with other growth and carcass traits. These results demonstrate that lmbr1 gene could be a genetic locus or linked to a major gene significantly affecting these growth and carcass traits in chicken.     

Efficient generation of transgenic chickens using the spermatogonial stem cells in vivo and ex vivo transfection

The highly efficient novel methods to produce transgenic chickens were established by directly in-jecting the recombinant plasmid containing green fluorescent protein (GFP) gene into the cock's testis termed as testis-medianted gene transfer (TMGT), and transplanting transfected spermatogonial stem cells (TTSSCs). For the TMGT approach,four dosages of pEGFP-N1 DNA/cationic polymer complex were injected intratesticularly. The results showed: (1) 48 h after the injection,the percentages of testis cells expressing GFP were 4.0%, 8.7%, 10.2% and 13.6% in the 50, 100, 150 and 200 μg/mL group, re-spectively. The difference from the four dosage groups was significant (P<0.05). On day 25 after the injection, a dosage-dependent and time-dependent increase in the number of transgenic sperm was observed. The percentages of gene expression reached the summit and became stable from day 70 to 160, being 12.7%, 12.8%, 15.9% and 19.1%, respectively. The difference from the four dosage groups was also significant (P<0.05). (2) 70 d after the injection, strong green fluorescent could be observed in the seminiferous tubules by whole-mount in-situ hybridization. (3) 70 d after the injection, the semen was collected and used to artificially inseminate wild-type females. The blastoderms of F1 and F2 transgenic chicken expressed GFP were 56.2% (254/452) and 53.2% (275/517), respectively. The detec-tion of polymerase chain reaction (PCR) of F1 and F2 transgenic chicken blood genomic DNA showed that 56.5% (3/23) of F1 and 52.9% (9/17) of F2 were positive. Southern blot showed GFP DNA was in-serted in their genomic DNAs. (4) Frozen whole mount tissue sections of F1 and F2 transgenic chicken liver, heart, kidney and muscle showed that the rates of green fluorescent positive were between 50.0% and 66.7%. (5) With the TTSSCs method, SSCs ex vivo transfected with GFP were transplanted into recipient roosters whose endogenic SSCs had been resoluted. The donor SSCs settled and GFP ex-pression became readily detectable in the frozen whole mount tissue sections of recepient testes. Moreover, sperms carrying GFP could be produced normally. The results of artificially inseminating wild-type females with these sperms showed 12.5% (8/64) of offspring embryo expressed GFP and 11.1% (2/18) hatched chicks were tested transgenic. Our data therefore suggest TMGT and TTSSCs are the feasible methods for the generation of transgenic chickens.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.