“三黄”鸡采精量和受精率的方差组分估计

用4种方法(Henderson方法Ⅰ、 MIVQUE、ML、REML)估计了两个“三黄”慢羽系的公鸡采精量和种蛋受精率的方差组分,并计算了它们与产蛋性状间的遗传相关。结果表明,采精量为中等到高遗传力性状(h2=0.29-0.3 9);受精率的遗传方差在品系之间存在着较大的差异,L系受精率性状的遗传力低,而Ⅰ系受精率为中等到高遗传力性状。采精量和受精率与开产日龄、 43周龄蛋重以及64周龄产蛋量间遗传相关不显著。此外,还对4种方差组分估计方法和两种数值转换方法的实际效果作了比较。     

Human Recombinant B7-H3 Expressed in E.colt Enhances T Lymphocyte Proliferation and IL-10 Secretion in Vitro

Since it was proposed in 1970, the two-signal hypothesis for T lymphocyte activation became widely accepted, which elucidated T cells required two distinct signals for optimal T helper precursor cell expansion. This model hypothesized that peptides presen…     

Smallest bitter taste receptor (T2Rs) gene repertoire in carnivores

Bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. Accordingly, carnivores, who encounter these toxic substances less often, should have fewer genes associated with bitter taste reception compared with herbivores and omnivores. To investigate the genetic basis of bitter taste reception, we confirmed bitter taste receptor (T2R) genes previously found in the genome sequences of two herbivores (cow and horse), two omnivores (mouse and rat) and one carnivore (dog). We also identified, for the first time, the T2R repertoire from the genome of other four carnivore species (ferret, giant panda, polar bear and cat) and detected 17-20 bitter receptor genes from the five carnivore genomes, including 12-16 intact genes, 0-1 partial but putatively functional genes, and 3-8 pseudogenes. Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species, supporting earlier speculations that carnivores have fewer T2R genes, herbivores an intermediate number, and omnivores the largest T2R gene repertoire. To further explain the genetic basis for this disparity, we constructed a phylogenetic tree, which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree, suggesting that carnivore T2Rs were conserved among mammals. Similarly, the small carnivore T2R family size was likely due to rare duplication events. Collectively, these results strengthen arguments for the connection between T2R gene family size, diet and habit.     

基于元分析的抗玉米丝黑穗病QTL比较定位

以玉米遗传连锁图谱IBM2 2005 Neighbors为参考图谱,通过映射整合不同试验中的抗玉米丝黑穗病QTL,构建QTL综合图谱。在国内外种质中,共发现22个抗病QTL,分布在除第7染色体外的9条玉米染色体上。采用元分析技术,获得2个“一致性”抗病QTL,图距分别为8.79 cM和18.92cM。从MaizeGDB网站下载“一致性”QTL区间内基因和标记的原始序列;采用NCBI网站在线软件BLASTx通过同源比对在2个“一致性”QTL区间内初步获得4个抗病位置候选基因。借助比较基因电子定位策略,将69个水稻和玉米抗性基因定位于玉米IBM2图谱上,在2个“一致性”QTL区间内分别发现1个水稻抗性基因,初步推断为抗病位置候选基因。本文结果为抗玉米丝黑穗病QTL精细定位和分子育种提供了基础。     

近交系小鼠微卫星DNA多态性的研究

随机选择位于小鼠不同染色体上的微卫星引物42对,用PCR技术对C3H、C57、BALB/c、DBA、TA2、T739、B615、BACB/c－nu－nu和SCID等9种实验室常用近交系小鼠微卫星DNA多态性进行了研究。结果显示有信息的40对引物中,9种近交系小鼠在各基因座上均出现一条清晰条带,28个基因座表现为多态性。其中D3Mit22、D7Nds1、D11Mit12、D12Nds2、D15Mit17、D16Mit3、D16Mit4基因座表现为显著多态性。T739、B615和TA2的遗传背景相近,其相似系数分别为90％和85％;其次为TA2、SCID和B615,其相似系数分别为80％和82.5％。结果表明所检测的小鼠符合近交要求,筛选出的引物能典型地反映9个近交系小鼠的品系特异性和遗传背景,可用于常规检测小鼠品系来源和遗传背景等。 Abstract：Forty-two microsatellites DNA loci on different chromosomes in nine kinds of inbred strain mice including C3H,C57,BALB/c,DBA,TA2,T739,B615,BALB/c-nu-nu and SCID were investigated by PCR analysis.It showed that all these mice tested display single allelic gene band with forty pairs of informative primers.Twenty-eight loci are polymorphisms,among which the polymorphisms of D3Mit22,D7Nds1,D11Mit12,D12Nds2,D15Mit17,D16Mit3,and D16Mit4 loci are significant.The genetic background of T739 was similarity with that of B615 and TA2 ,the similarity indices were 90％ and 85％ respectively;and that of TA2 was similarity with SCID and B615,the similarity indices were 80％ and 82.5％.These results suggest that these mice tested meet the request of inbred strain.Screened primers showing marked polymorphisms topically reflect the speciality of strains and genetic backgrounds,which could be used in determining the strains origin and genetic background of mice.     

盐生植物碱地肤对盐碱胁迫的生理响应特点

以天然盐生植物碱地肤(Kochia sieversiana)为材料,采用人工生态模拟方法对其施加0~480mmol/L的盐胁迫(摩尔比1∶1的NaCl和Na2SO4)和碱胁迫(摩尔比1∶1的NaHCO3和Na2CO3),测定了盐碱胁迫下的相对生长率(RGR)、叶绿素含量及丙二醛含量.结果表明:低浓度的盐胁迫(80mmol/L)对碱地肤的生长具有刺激作用,其在高达480mmol/L的盐胁迫或400mmol/L的碱胁迫下仍能存活并维持一定的生长,具有强抗盐性和强抗碱性;在相同盐浓度下,碱地肤受碱胁迫的伤害强度和对碱胁迫所做出的胁变反应均大于对盐胁迫.可见,碱地肤的抗盐性强于抗碱性,受碱胁迫的伤害大于盐胁迫,维持高含水量可能是碱地肤适应高强度盐碱胁迫的重要特性.     

用野生醋栗花粉匀桨诱导栽培番茄变异的初步研究

实验以79286栽培番茄品种为受体,用野生醋栗花粉匀桨物质处理该受体植株柱头再对其授粉。从诱导后代中获得了结果习性、果肩色等具有某些醋栗性状的变异,并从中选育出一个耐储性好、多果型的番茄新品系。其受体番茄由聚伞花序转化为总状花序型的频率为7.8-23%。酶碎结果树有4-5个增加值6-8个。过大小介于供体与受体两者之间。Abstract: The exeperiment used tomato as the recipient and the pollen homogenate of wild-gooseberry as the donor. We treated the matuma of recipient with the pollen homogenate of donor, and then pollinated with normal pollen of the maternal plants. Several offspring of changed characters, as the size of fruit and the fruit number were obtainted in generation H2 From these plants, we have chosen a new variety with store-resisting and multifruit type. The above results show that the method was effective to practical tomato breeding and multifruit type. The above results show that the method was effective to practical tomato breeding. However some theoretical problem need to be further studied.     

PrP mutants with different numbers of octarepeat sequences are more susceptible to the oxidative stress

One of the physiological functions of cellular prion protein(PrP C )is believed to work as a cellular resistance to oxidative stress,in which the octarepeats region within PrP plays an important role.However,the detailed mechanism is less clear.In this study,the expressing plasmids of wild-type PrP (PrP-PG5)and various PrP mutants containing 0(PrP-PG0),9(PrP-PG9)and 12(PrP-PG12)octarepeats were generated and PrP proteins were expressed both in E.coli and in mammalian cells.Protein aggregation and formation of carbonyl groups were clearly seen in the recombinant PrPs expressed from E.coli after treatment of H2O2.MTT and trypan blue staining assays revealed that the cells expressing the mutated PrPs within octarepeats are less viable than the cells expressing wild-type PrP.Statistically significant high levels of intracellular free radicals and low levels of glutathione peroxidase were observed in the cells transfected with plasmids containing deleted or inserted octarepeats.Remarkably more productions of carbonyl groups were detected in the cells expressing PrPs with deleted and inserted octarepeats after exposing to H2O2.Furthermore,cells expressing wild-type PrP showed stronger resistant activity to the challenge of H2O2 at certain extent than the mutated PrPs and mock. These data provided the evidences that the octarepeats number within PrP is critical for maintaining its activity of antioxidation.Loss of its protective function against oxidative stress may be one of the possible pathways for the mutated PrPs to involve in the pathogenesis of familial Creutzfeldt-Jacob diseases.     

Persistence of VRC01-resistant HIV-1 during antiretroviral therapy

VRC01,a broadly neutralizing monoclonal antibody(bnmAb),can neutralize a diverse array of HIV-1 isolates by mimicking CD4 binding to the envelope glycoprotein gp120.We have previously demonstrated the presence of VRC01-resistant strains in an HIV-1 infected patient during antiretroviral therapy.Here,we report follow-up studies of two subsequent samples from the same patient.With genetic and phenotypic analysis of over 70 full-length molecular clones of the HIV-1 envelope,we show that VRC01-resistant HIV-1 continued to exist and change in its proportion of the infecting virus during treatment with a highly active antiretroviral therapy.Consistent with our previous observation,the resistant phenotype was associated with a single asparagine residue at position 460(N460),a potential N-linked glycosylation site in the V5 region.The persistence and continuing evolution of VRC01-resistant HIV-1 in vivo presents a great challenge to our future preventative and therapeutic interventions based on VRC01.