中国叉茎管蚜蝇属及一新种记述(双翅目:食蚜蝇科)(英语)

叉茎管蚜蝇属Tigridemyia与墨管蚜蝇属 Mesembrius和美管蚜蝇属 Mallota形态相似,过去曾被作为后二属的亚属.但此属的雄性外生殖器阳茎的射精管端部4分叉与墨管蚜蝇属和美管蚜蝇属区别明显,因此,其属地位应予肯定.作者在整理中国的食蚜蝇标本时,发现该属1新种,刺腿叉茎管蚜蝇Tigridemyia acanthogemurilis sp.nov,加之过去已记录的1种,我国已知叉茎管蚜蝇属2种.本文描述了新种,并给出了中国已知2种的检索表和形态特征图及其分布.模式标本保存于华南农业大学植保系昆虫标本室.     

The Drosophila ribosomal protein L14-encoding gene, identified by a novel Minute mutation in a dense cluster of previously undescribed genes in cytogenetic region 66D

The Minute phenotype results from mutations at?>50 loci scattered throughout the genome of Drosophila. Common traits of the Minute phenotype are short and thin bristles, slow development, and recessive lethality. Here, we report a novel P-element induced Minute mutation, P{lacW}M(3)66D ¹ , that maps to region 66D on chromosome 3L. Flies heterozygous for P{lacW}M(3)66D ¹ have a strong Minute phenotype. Molecular characterisation of the chromosomal region revealed three previously undescribed Drosophila genes clustered within a 5-kb genomic fragment. Two of the genes have significant sequence homology to genes for the mammalian ribosomal proteins L14 and RD, respectively, and share a joint 240-bp promoter region harbouring the P-element insert. Quantitative Northern blot analyses showed the mutation to affect RPL14 mRNA levels only. Interestingly, the reduction in abundance of RPL14 mRNA is not constitutive, indicating that the promoter function abolished by the inserted P-element is utilised with different efficiencies in different developmental situations. Remobilisation of the P element produced wild-type flies with normal levels of RPL14 mRNA, demonstrating that the mutant phenotype is caused by the insertion. P{lacW}M(3)66D ¹ joins a growing list of Minute mutations associated with ribosomal protein-haploinsufficiency.     

野大豆(Glycine soja)叶绿体的光谱及其激子能量转移

野大豆叶绿体在低温(77K)时出现三条荧光发射谱带,它们来源于不同的色素蛋白复合体。 在纳秒脉冲激光激发下,捕光天线色素的相对荧光量子产额,随激光强度的增加有明显下降现象。用激子理论和动力学方程讨论和计算了激子扩散参量。指出激子转移是随机的,非相干的。     

Identification of differential genes in the ovary relative to the testis and their expression patterns in half-smooth tongue sole (Cynoglossus semilaevis)

Half-smooth tongue sole (Cynoglossus semilaevis) is a rare marine flatfish whose mature ovary and testis greatly differ in volume and weight. The length and weight of mature females are over twice greater than those of mature males. To obtain sufficient information on gonad differentiation and the relationship between gonad development and growth in the fish, we compared gene expression between the ovary and testis using suppression subtractive hybridization (SSH). Testis cDNAs are subtracted from...     

Leveraging Distant Relatedness to Quantify Human Mutation and Gene-Conversion Rates

The rate at which human genomes mutate is a central biological parameter that has many implications for our ability to understand demographic and evolutionary phenomena. We present a method for inferring mutation and gene-conversion rates by using the number of sequence differences observed in identical-by-descent (IBD) segments together with a reconstructed model of recent population-size history. This approach is robust to, and can quantify, the presence of substantial genotyping error, as validated in coalescent simulations. We applied the method to 498 trio-phased sequenced Dutch individuals and inferred a point mutation rate of 1.66 × 10⁻⁸ per base per generation and a rate of 1.26 × 10⁻⁹ for <20 bp indels. By quantifying how estimates varied as a function of allele frequency, we inferred the probability that a site is involved in non-crossover gene conversion as 5.99 × 10⁻⁶. We found that recombination does not have observable mutagenic effects after gene conversion is accounted for and that local gene-conversion rates reflect recombination rates. We detected a strong enrichment of recent deleterious variation among mismatching variants found within IBD regions and observed summary statistics of local sharing of IBD segments to closely match previously proposed metrics of background selection; however, we found no significant effects of selection on our mutation-rate estimates. We detected no evidence of strong variation of mutation rates in a number of genomic annotations obtained from several recent studies. Our analysis suggests that a mutation-rate estimate higher than that reported by recent pedigree-based studies should be adopted in the context of DNA-based demographic reconstruction.     

A genetic and spatial Bayesian analysis of mastitis resistance

A nationwide health card recording system for dairy cattle was introduced in Norway in 1975 (the Norwegian Cattle Health Services). The data base holds information on mastitis occurrences on an individual cow basis. A reduction in mastitis frequency across the population is desired, and for this purpose risk factors are investigated. In this paper a Bayesian proportional hazards model is used for modelling the time to first veterinary treatment of clinical mastitis, including both genetic and environmental covariates. Sire effects were modelled as shared random components, and veterinary district was included as an environmental effect with prior spatial smoothing. A non-informative smoothing prior was assumed for the baseline hazard, and Markov chain Monte Carlo methods (MCMC) were used for inference. We propose a new measure of quality for sires, in terms of their posterior probability of being among the, say 10% best sires. The probability is an easily interpretable measure that can be directly used to rank sires. Estimating these complex probabilities is straightforward in an MCMC setting. The results indicate considerable differences between sires with regards to their daughters disease resistance. A regional effect was also discovered with the lowest risk of disease in the south-eastern parts of Norway.     

An Effective Method for Raising Antisera Against β-defensins: Double-copy Protein Expression of mBin1b in E. coli

Defensins are a family of evolutionarily relatedvertebrate antimicrobial peptides with a characteristicβ-sheet-rich fold and a framework of six disulphide-linkedcysteines. The two main defensin subfamilies, α- andβ-defensin, differ in the length of pep…