Effective use of nitrocellulose-blotted antigens for phage display monoclonal antibody selection

The combinatorial phage display library approach to antibody repertoire cloning offers a powerful tool for the isolation of specific antibodies to defined target antigens. Panning strategy is often a very critical point for selecting antibody displayed on the surface of bacteriophages. Most selection strategies described to date have relied on the availability of purified and often recombinant antigen, providing the possibility to perform selections on a well defined antigen source. However, when the antigen is difficult to purify by means of laborious and time-consuming chromatography procedures, panning of phage antibody libraries has to be performed on complex antigen sources such as cell surfaces or tissue sections, or even by in vivo selection methods. This provides a series of technical and experimental complications. In the present work, we successfully generated a mouse monoclonal antibody fragment from a phage display library directed against protein E7 of HPV18 avoiding antigen purification as for immunizing mice as for antibody library selection. Our work demonstrates the feasibility of phage antibody selections on antigens transferred to a nitrocellulose membrane as solid support, using one-dimensional polyacrylamide gel electrophoresis system as the only practice to separate a given antigen present in bacterial crude cell lysate.     

Polymorphism of erythrocyte glucosephosphate isomerase in sheep

An electrophoretic analysis of glucosephosphate isomerase (GPI) in seven Italian sheep populations suggests that this locus is more polymorphic than previously supposed. The observed phenotype distributions are in agreement with the hypothesis of the existence of three codominant alleles, GPI*F, GPI*S and GPI*N, GPI*S being the most frequent (0.935 ÷ 1.000).     

Sexual selection for syntax and kin selection for semantics: problems and prospects

The evolution of human language, and the kind of thought the communication of which requires it, raises considerable explanatory challenges. These systems of representation constitute a radical discontinuity in the natural world. Even species closely related to our own appear incapable of either thought or talk with the recursive structure, generalized systematicity, and task-domain neutrality that characterize human talk and the thought it expresses. W. Tecumseh Fitch’s proposal (2004, in press) that human language is descended from a sexually selected, prosodic proto-language that approximated its syntactic complexity, and later acquired semantics thanks to kin selection for its use as a means of pedagogical transmission, has the promise of meeting these explanatory challenges. However, Fitch’s theory raises two problems of its own: (1) according to Boyd and Richerson (1996, Proc. Br. Acad. 88: 77–93), circumstances in which pedagogy is adaptive are inevitably rare in nature, and (2) it is unlikely that our non-discursive precursors had generally systematic, task-domain neutral thoughts to communicate to their offspring. I propose solutions to these problems. Pedagogy would be favored in a population where complex rituals dominated diverse aspects of life. Prosodic proto-language could emerge as the medium of pedagogic transmission. As this medium was used to teach a greater variety of tasks, it would become increasingly general and domain neutral. The presence and importance of such a system of communication in hominid populations could then drive, via Baldwinian mechanisms, the evolution of a kind of ‘thinking for speaking’ (Slobin 1991, Pragmatics 1: 7–25) characterized by recursive structure, generalized systematicity, and task-domain neutrality.     

Polymorphism of ISSR-PCR markers in Tuvinian population of reindeer Rangifer tarandus L

The results of the first analysis of the reindeer population inhabiting the south of Siberia, the Republic of Tyva (Tuva), performed by use of inter-simple sequence repeat (ISSR) technique, are reported. Using ISSR-PCR with two primers, a total of 71 fragments of different size were detected. Furthermore, for the population examined the indices of the mean pairwise similarity and the mean heterozygosity were calculated. The approach used can be recommended as a useful tool for the genetic diversity monitoring in Tuvinian population of reindeer.     

Polymorphism and differential selection for the sexes.

Various genetic models with different fitnesses for the sexes are investigated. Only a limited set of fitness values will result in a stable polymorphism, and the rate of approach to these equilibrium frequencies is extremely slow. These results indicate that there are problems associated with the interpretation of some human genetic traits by such models.     

Polymorphism of erythrocyte malic enzyme in the goat

Three electrophoretic variants of erythrocyte malic enzyme (ME) in goats were reported. Inheritance data indicate that they are controlled by codominant alleles. The allele frequencies in four Mediterranean populations are given.     

An isoelectric focusing procedure for erythrocyte membrane proteins and its use for two-dimensional electrophoresis

Procedures are described and evaluated for one-dimensional isoelectric focusing of erythrocyte membrane dissolved in lysine, urea, and Triton X-100 without using sodium dodecyl sulfate (SDS) and for two-dimensional electrophoresis with SDS in the second dimension. The membrane was completely dissolved, most of the proteins including the anion porter(s) entered the focusing gel, and complex, well-resolved patterns were seen. Ampholines, 2-mercaptoethanol, or SDS in the applied sample each seriously reduced focusing resolution and phenylmethylsulfonyl fluoride blurred the patterns. The two-dimensional patterns showed more and sharper spots than did patterns obtained from membrane initially dissolved with SDS. Anion porter spots were seen with both procedures. However, major cytoskeletal proteins were much less well recovered with the former procedure than with the latter.     

Polymorphism of ISSR-PCR markers in Tuvinian population of reindeer Rangifer tarandus L.

The results of the first analysis of the reindeer population inhabiting the south of Siberia, the Republic of Tyva (Tuva), performed by use of inter-simple sequence repeat (ISSR) technique, are reported. Using ISSR-PCR with two primers, a total of 71 fragments of different size were detected. Furthermore, for the population examined the indices of the mean pairwise similarity and the mean heterozygosity were calculated. The approach used can be recommended as a useful tool for the genetic diversity monitoring in population of reindeer.     

Polymorphism of erythrocyte G-6-PD in the baboon

Blood samples from several populations of baboons (genus Papio) were examined for G-6-PD variants. Several G-6-PD phenotypes were detected by starch gel electrophoresis. The so-called fast variant phenotypes of G-6-PD in baboons differ from human variant phenotypes in several physicochemical constants.     

Definition of the concept "information" and prospects of its use in biology

It is suggested to define the concept "information" as a "guide to action",--as a sum of methods, rules and data necessary for constructing an operator which should ensure an increase in the probability of occurrence of some event called a "goal" in the initial situation. The main properties of information, the possibility of estimating its volume, value and efficiency, as well as the problems related to information dynamics are considered. Some prospects of using the formulated concepts in biology are discussed.     

Enzyme immunoassays for the detection of microbial antigens and prospects for improved assays

The rapid diagnosis of viral infections is an important tool in the management of patients with infectious diseases. Solid-phase enzyme immunoassays have proved to be useful tools for the direct detection of the antigens of some viruses directly in clinical specimens. Such assays have been particularly useful in the diagnosis of viral infections in the gastrointestinal and respiratory tracts. However, standard solid-phase enzyme immunoassays often do not display sufficient sensitivity for the diagnosis of all cases of viral infections. Techniques which might be utilized to increase the sensitivity of solid-phase immunoassays include the use of monoclonal antibodies to maximize the efficiency of the antigen-antibody interactions and the use of high-turnover enzymes to increase the amount of signal generated by the ensuing enzyme-substrate reactions. In addition, techniques making use of nucleic acid hybridization have a great deal of potential for the accurate detection of viral nucleic acids in human body fluids. The successful application of these techniques to the diagnosis of viral infections could lead to a marked improvement in the care of patients with suspected infectious diseases as well as to a decrease in the transmission of viral infections to high-risk individuals.     

Polymorphism and selection of rpoS in pathogenic Escherichia coli

Background  

Though RpoS is important for survival of pathogenic Escherichia coli in natural environments, polymorphism in the rpoS gene is common. However, the causes of this polymorphism and consequential physiological effects on gene expression in pathogenic strains are not fully understood.     

Lethality of palindromic DNA and its use in selection of recombinant plasmids

A plasmid derived from ColE1 is constructed so that the removal of one restriction endonuclease HindIII fragment allows the ends of the remaining single fragment (the replicator) to be joined, generating a palindromic sequence 2394 bp in length. The circular species thus produced gives rise to transformants of E. coli at very low frequency. Since the palindromic sequence is effectively lethal to a plasmid containing it, the replicator will give rise to more transformants when the restriction fragment originally removed from it is replaced by another. This principle can be exploited to allow the efficient molecular cloning of unselected restriction fragments.     

Antisense polynucleotides and prospects for their use in fighting viruses

Natural or synthetic anti-sense (as) polynucleotides complementary to distinct functional regions of mRNA (asRNA or asDNA) are able to inhibit the expression of any target gene. If certain viral mRNAs important for virus replication are targeted the inhibition of viral infection by asRNA or asDNA takes place. Inhibitory effects of complementary polynucleotides on gene activity in eukaryotic cells is due to the disturbance of translation of corresponding mRNAs as well as to the impairment of their splicing or transportation from the nuclei to cytoplasm. In prokaryotic cells, obviously, only the first factor is operating. The recombinant genes programming anti-viral asRNA can confer the resistance to the infection by other virus to the transformed cells. The resistance to viral infection observed in transgenic animals, expressing asRNA genes, may be considered as a new unnatural form of informational immunity.