中国黑腹果蝇种组的组成与分布

1999~2004年,对全国27个省市的果蝇进行调查的结果表明:中国黑腹果蝇种组由10个种亚组组成,共67种.其中包括6个新种(D.sp.likeelegans,D.sp.likeauraria,D.sp.liketrapezifrons1,D.sp.liketrapezifrons2,D.sp.liketakahashii,D.chayusp nov);4个新记录种(D.giriensis,D.ogumai,D.ohnishii,D.pseudobaimaii);6个广布种(D.auraria,D.kikkawai,D.melanogaster,D.simulans,D.suzukii和D.takahashii).分布于全国33个省市,垂直分布的海拔高度在3 000 m以下.     

不同基因型黑腹果蝇的寿命比较

为了研究遗传因素对黑腹果蝇寿命的影响，本文用三角瓶液体饲养法饲养了４个基因型不同的果蝇品系（＃１、＃２、＃３和＃４的基因型分别为ＷＷＶｇＶｇＳｍＳｍＣｈＣｈ，ｗｗＶｇＶｇＳｍＳｍＣｈＣｈ，ＷＷｖｇｖｇＳｍＳｍＣｈＣｈ和ｗｗＶｇＶｇｓｍｓｍｃｈｃｈ），并记录和比较了它们的寿命。结果显示，群体的半数死亡期，平均寿命和最高寿命三项指标均呈现＃１＞＃２和＃３，＃２和＃３＞＃４的规律。提示显性基因多的果蝇品系寿命更长，从而支持了作者先前提出的“多显性基因决定长寿”的假说。     

基因组的进化与内含子中的基因的进化

论述了基因组整体进化过程中内含子所含的基因的进化．分析了内含子的起源方式与内含子中的基因种类的关系,并结合基因组在大小、组成等方面进化过程中内含子的演化趋势,探讨了内含子中的基因,特别是核仁小分子ＲＮＡ基因的进化规律．同时,对于内含子中的基因的进化,提出了一些可能的途径．     

黑腹果蝇热激蛋白基因家族的生物信息学分析

热激蛋白是细胞或生物体受到热激后新合成的一类遗传上高度保守的蛋白,在生物体中普遍存在,在细胞生长、发育、分化、基因转录等功能方面发挥重要的作用.本研究利用生物信息学方法首次对黑腹果蝇(Drosophila melanogaster)全部热激蛋白进行分析.结果表明,黑腹果蝇热激蛋白共有HSPC(HSP90)、HSPA(H...     

一种黑腹果蝇原种的培养方法

黑腹果蝇是高等院校遗传学实验教学中的一个重要材料,培养出健康适龄的果蝇对实验结果的重要性显得十分重要。因此,本文较为详细地介绍了一种从培养基的制备到培养全过程的黑腹果蝇培养方法,以期为培养健康适龄果蝇,并用于遗传学实验教学提供一定的参考。     

生地对黑腹果蝇寿命的影响

观察了生地对黑腹果蝇寿命的影响。实验组培养基药物浓度分别为０．３５％、０．７０％和１．４０％,对照组培养基不加药物。实验结果表明,与对照组相比,三种浓度的生地都能延长雌雄果蝇的平均寿命和最高寿命;在半数死亡期方面,０．３５％生地对雌雄果蝇都能延长,０．７０％生地仅能延长雌性果蝇,而１．４０％生地对雌雄果蝇均无延长作用。提示生地有延缓衰老的作用 。     

黄芪复方对黑腹果蝇寿命的影响

长寿和衰老是寿命的两种不同表现形式，统受许多对等位基因控制【“」，其中，每对等位基因都有完全显隐性之分，显性基因控制长寿，故称长寿基因，隐性基因控制衰老，故称衰老基因。由于父母携带长寿基因和衰老基因的数目不同，每个人携带该两类基因的数量也不同，但是，无论是携带的长寿基因多，还是衰老基因多，人们均无法对其进行任何修改。不过，在体内外环境优越的条件下，长寿基因可充分表现，因而携带长寿基因多者，可表现为长寿。相反，在环境不良的条件下，长寿基因不能充分表现，结果其作用可能几乎近似于衰老基因，因而一个人即…     

氯化钇对黑腹果蝇生育率的影响

探讨稀土元素钇（Y）对黑腹果蝇生育率的影响。在不同浓度（1、4、16 mg/L）氯化钇（YCl₃）培养基中饲养野生型黑腹果蝇（红眼Canton-S）。并设置普通培养基作为对照，收集8 h内羽化的果蝇，雌雄果蝇分别放置在0、1、4、16 mg/L的YCl₃培养基中喂养10 d，后分别与异性果蝇按照1:3的比例在普通培养基中进行杂交，7 d后去除异性果蝇，第10 d开始统计羽化的果蝇总数量（F1），连续统计5 d后，计算新生成果蝇的数目。结果表明YCl₃浓度为1 mg/L时，雄性果蝇繁殖能力未见明显异常；浓度增加到4 mg/L时，实验组雄果蝇的生育率与对照组相比有所下降；随着浓度的不断增加，雄性果蝇的生育率下降80%。然而以雌性果蝇作为实验对象，无论是在低浓度还是高浓度的YCl₃喂养，其生育率与对照组相比没有明显下降，统计学没有显著差异（P＞0.05）。YCl₃超过一定浓度会降低黑腹果蝇的繁殖能力，对果蝇的生殖系统产生不利影响。并且我们此次实验发现，随着YCl₃浓度的升高，对雄性果蝇生殖系统的危害要远大于对雌性果蝇的影响，存在显著的性别差异且呈现明显的剂量效应关系。     

黑腹果蝇抗真菌肽基因Drs的真核可溶性表达

将黑腹果蝇（Drosophila melanogaster）抗真菌肽基因Drosomycin（Drs）克隆到pPICZα-A载体中,构建分泌型表达载体pPICZα-A-Drs,转化宿主菌Pichia pastoris X-33.在 AOX1（醇氧化酶）启动子调控下,抗真菌肽DRS成功表达,其分子量约为5 kD.抑菌试验显示,DRS对供试真菌有明显的抑菌活性.采用考马斯亮蓝法测定抗真菌肽的具体表达量,并优化了诱导条件.     

Xenogeneic homologous genes, molecular evolution and cancer therapy

Cancer is one of the main causes for death of human beings to date, and cancer biotherapy (mainlyimmunotherapy and gene therapy) has become the most promising approach after surgical therapy, radiotherapy andchemotherapy. However, there are still many limitations on cancer immunotherapy and gene therapy; therefore great ef-fort is being made to develop new strategies. It has been known that, in the process of evolution, a number of genes, theso-called xenogeneic homologous genes, are well-conserved and show the structural and/or functional similarity betweenvarious species to some degree. The nucleotide changes between various xenogeneic homologous genes are derived frommutation, and most of them are neutral mutations. Considering that the subtle differences in xenogeneic homologousgenes can break immune tolerance, enhance the immunogenicity and induce autologous immune response so as to elimi-nate tumor cells, we expect that a strategy of inducing autoimmune response using the property of xenogeneic homologousgenes will become a new therapy for cancer. Moreover, this therapy can also be used in the treatment of other diseases,such as autoimmune diseases and AIDS. This article will discuss the xenogeneic homologous genes, molecular evolutionand cancer therapy.     

灵长类酪氨酸酶基因外显子1序列进化研究

酪氨酸酶是黑色素合成当中的关键酶,酪氨酸酶基因的突变将导致白化病,测定了黑猩猩,倭黑猩猩,大猩猩、猩猩、长臂猿、食蟹猴、猴猴９个灵长类中代表物种的酪氨酸酶基因外显子１的ＤＮＡ序列。     

Molecular evolution of the exon 2 of CHS genes and the possibility of its application to plant phylogenetic analysis

The exon 2 of chalcone synthase (CHS) gene is relatively conserved during evolution. In this study, three exon 2 fragments from two species in gymnosperm (Cycas panzhihuaensis, Ginkgo biloba) and seven from four species in angiosperm (Magnolia denudata, Salix babylonica, Nymphaea tetragona, Camellia japonica) have been amplified by PCR from genomic DNA and sequenced. Together with other 73 sequences ofCHS collected from EMBL database and literature, these sequences, which embrace 19 families of gymnosperm and angiosperm, have been analyzed for their phylogenetic relations by parsimony method. The result indicated that sequences from the same systematic family usually grouped together except those from Theaceae, Magnoliaceae and Nymphaeaceae. The relative rate test revealed the rate heterogeneity of CHS genes among the families. For the nucleotide substitution the sequences from Asteraceae and Solanaceae evolve faster than those from the other families analyzed while the sequences from Poaceae, Asteraceae and Solanaceae evolve faster for the nonsynonymous substitution. These results suggest that the duplication and extinction events of CHS genes are different among systematic families, therefore it seems impractical to look for orthologous sequences from CHS genes to study plant phylogeny at the family level andlor above. However, it is possible to do so below the family level.     

Origin and evolution of new genes

Organisms have variable gcnome sizes and contain different numbers of genes. This difference demonstrates that new gene origination is a fundamental process in evolutionary biology. Though the study of the origination of new genes dated back more than half a century ago, it is not until the 1990s when the first young genejingwei was found that empirical investigation of the molecular mechanisms of origination of new genes became possible. In the recent years, several young genes were identified and the studies on these genes have greatly enriched the knowledge of this field. Yet more details in a general picture of new genes origination are to be clarified. We have developed a systematic approach to searching for young genes at the genomic level, in the hope to summarize a general pattern of the origination and evolution of new genes, such as the rate of new gene appearance, impact of new genes on their host genomes, etc.     

黑腹果蝇Drosophila melanogaster因PM体系造成的卵巢败育的实验测定

黑腹果蝇在北美的群体自1950年后受到 P 转座子的侵入,现在该区域的果蝇几皆成为P 型,而我国境内的果蝇在 P 因子的特征上具有很大的差别,从我们22个品系的杂交实验,子代卵巢解剖的实验测定中可以得到明确的证明。杂交组合正反交结果不同,证明与细胞质型有关。     

Randomization of protein encoding gene during species evolution

Employing chi-square teat, the authors observed the bias of 4 kinds of bases’ locating in 3 codon positions in gene sequence, and proved that there is a positive correlation between higher chi-square value and protein coding structure. By this, the observatlon that genes undergo progressive reduction in chi-values along evolution direction will reflect the progressive randomization of gene structures and the loss of the characteristics of protein coding sequences. The result proposed that during the evolution of life, genes are unexpectedly degenerating.     

Detecting positive darwinian selection in brain-expressed genes during human evolution

To understand the genetic basis that underlies the phenotypic divergence between human and non- human primates, we screened a total of 7176 protein-coding genes expressed in the human brain and compared them with the chimpanzee orthologs to identify genes that show evidence of rapid evolution in the human lineage. Our results showed that the nonsynonymous/synonymous substitution (Ka/Ks) ratio for genes expressed in the brain of human and chimpanzee is 0.3854, suggesting that the brain-expressed genes are under functional constraint. The X-linked human brain-expressed genes evolved more rapidly than autosomal ones. We further dissected the molecular evolutionary patterns of 34 candidate genes by sequencing representative primate species to identify lineage-specific adaptive evolution. Fifteen out of the 34 candidate genes showed evidence of positive Darwinian selection in human and/or chimpanzee lineages. These genes are predicted to play diverse functional roles in em- bryonic development, spermatogenesis and male fertility, signal transduction, sensory nociception, and neural function. This study together with others demonstrated the usefulness and power of phy- logenetic comparison of multiple closely related species in detecting lineage-specific adaptive evolu- tion, and the identification of the positively selected brain-expressed genes may add new knowledge to the understanding of molecular mechanism of human origin.