Application of allyloxycarbonyl group as a protecting group to oligodeoxyribonucleotide synthesis

The allyloxycarbonyl (AOC) group, known as an efficient amino protective group in solution-phase synthesis of nucleotides, has been used for the first time in solid-phase oligonucleotide synthesis. The efficiency of the new procedure is compared with that of the conventional N-acyl protection.     

Blood group and serum protein polymorphisms in a population group of Moldavians

The distribution of the alleles and haplotypes for blood groups A1A2B0, MNSs, RHESUS, P1, KELL-CELLANO and biochemical markers of the alleles of loci AMY2, HPA, GC, C3, TF, BF, CP, PI (including subtypes) were studied in 125 Moldavian individuals from Karahasani settlement, Stefan-Voda District, Republic of Moldavia. The results show that the gene pool of Moldavians is similar to those of Southeastern European populations.     

Rabbit latent group a allotypes: characterization and relationship to nominal group a allotypic specificities.

Latent group a allotypes were detected with a sensitive radioimmune inhibition assay. Sera, IgG preparations, and antibody fractions containing these allotypes inhibited the binding of insolubilized allotypic antisera to various radiolabeled antigens including IgG pools, homogeneous antibodies, and, in the case of a3, a VH fragment from a3/b4 IgG. Several different group a antiallotypic sera were used in the assays and all gave similar results. Comparison of inhibition curves for nominal and latent allotypes indicated that the full spectrum of allotypic subspecificities may be expressed in latent allotypes. Hemagglutination studies carried out with five sera containing high levels of latent allotypes confirmed the results obtained with the radioimmunoassay and indicated that inhibition values did not, at least in four of the five samples studied, reflect the presence of antiallotype antibodies.     

Functional group substitutions of the branchpoint adenosine in a nuclear pre-mRNA and a group II intron.

Splicing of nuclear mRNA precursors (pre-mRNAs) takes place in the spliceosome, a large and complex ribonucleoprotein. Nuclear pre-mRNA splicing and group II intron self-splicing occur by a chemically identical pathway involving recognition of a specific branchpoint adenosine and nucleophilic activation of its 2'-hydroxyl group. The chemical similarity between these two splicing reactions, as well as other considerations, have suggested that the catalytic core of the spliceosome and group II introns may be related. Here we test this hypothesis by analyzing splicing and RNA branch formation of a pre-mRNA and a group II intron in which the branchpoint adenosine was substituted with purine base analogues. We find that replacement of the branchpoint adenosine with either of two modified adenosine analogues or guanosine leads to remarkably similar patterns of splicing and RNA branch formation in the two systems.     

Third-party grooming in a captive chimpanzee group

Social grooming is ubiquitous among the captive chimpanzees at Chester Zoo. Seven individuals were chosen here for a study of third-party social dynamics. The grooming decisions of five adult males were analysed, but only insofar as they directed attention to a mother–daughter pair. Uniquely, the daughter was an unpopular and physically disabled subadult whose congenital motor impairments prevented her from grooming others effectively. The impetus for this study was the observation that some males increased their grooming towards the disabled daughter during days when the mother had a tumescent anogenital swelling (sexually attractive to males) compared to days when the mother was not tumescent (less attractive). Apparently, males were grooming the daughter with no possibility of payback (because the daughter could never “return the favour”). A “grooming rate” (avg. grooming time/hour) was calculated that showed the grooming efforts of all five males towards both mother and daughter. These rates were compared on days when (1) the mother’s anogenital swelling was tumescent, and (2) days when the swelling was not tumescent. Each male showed a different pattern of behaviour. Two males groomed the daughter significantly more when the mother was tumescent. Results for all males were graphed against the quality of the social relationship between each male and the mother. Apparently, only males that had a weaker relationship to the mother groomed the daughter more when the mother was tumescent. This pattern did not exist for males with a stronger relationship to the mother. Possibly, the insecure males were using the disabled daughter as a way to curry favour with the attractive mother. If this is confirmed, then this type of triadic situation is a possible setting for indirect reciprocity to occur.     

Explosive radiation of a bacterial species group

The current diversity of life on earth is the product of macroevolutionary processes that have shaped the dynamics of diversification. Although the tempo of diversification has been studied extensively in macroorganisms, much less is known about the rates of diversification in the exceedingly diverse and species-rich microbiota. Decreases in diversification rates over time, a signature of explosive radiations, are commonly observed in plant and animal lineages. However, the few existing analyses of microbial lineages suggest that the tempo of diversification in prokaryotes may be fundamentally different. Here, we use multilocus and genomic sequence data to test hypotheses about the rate of diversification in a well-studied pathogenic bacterial lineage, Borrelia burgdorferi sensu lato (sl). Our analyses support the hypothesis that an explosive radiation of lineages occurred near the origin of the clade, followed by a sharp decay in diversification rates. These results suggest that explosive radiations may be a general feature of evolutionary history across the tree of life.     

Emigration in a black howling monkey group

From August 1989 to January 1994, we monitored the age-sex composition of a small group of Alouatta carayainhabiting a 2-ha seminatural forest. During this period we observed seven cases of emigration: four by juvenile females, two by subadult females, and one by a subadult male. Five subjects formed a new bisexual group living in a marginal 0.3-ha portion of the site. Four of them died. Male changes occurred and seem to be followed by infanticides.     

A morphogenetic system matched to a group

A period of morphogenesis is operationally defined as a system. This period precedes cell differentiation and is axially expressed. Six interacting elements of structure are defined utilizing Spemann and Mangold's heteroplastic transplantation experiments. The system generates thirty-six interactions, given a rule of composition and specific premises. The element set and operation is matched to the symmetric group S₃.     

Stereochemistry of peptides containing a thioacyl group

Endothiopeptides are oligopeptides in which one or more oxoacyl moieties in peptide groups are replaced with thioacyl moieties. The stereochemical consequences of this replacement are discussed and compared with results from X-ray crystallographic determinations of small oligopeptides containing one or two thiopeptide groups. The analysis shows that the conformations normally observed around C alpha carbon atoms in proteins are also stereochemically favourable for peptides in which a thiopeptide group has been introduced. Limitations are only present in cases where the thiopeptide is part of structural elements like helices and beta-sheets. This opens the possibility of using one or more thiopeptide groups as functional modifiers of biologically active oligopeptide and protein molecules.     

Variation of group composition and spatial structure with group size in a sex-changing fish

Current knowledge of stable social groups of different size and structure suffers from a paucity of data on processes of group formation and development. If, for stable groups of one species, fission, growth, or other features of development reflect a uniform process operating on all groups, one might expect any group at one point in time to represent a single stage in the developmental process. Thus, unless group development is synchronous, a population should contain groups at all stages. A simple way to provide information about group development is to describe a large number of groups in a uniform habitat and to arrange the data along a variable axis, such as group size, that is thought to vary directly with development. A study was conducted on the tropical marine fish Anthias squamipinnis. Groups ranged in size from 1 to 370 fish. Small groups were spatially unitary. Intermediate-sized groups were divided into two spatially separate subgroups, i.e. were bipartite. Large groups were divided into three subgroups, i.e. were tripartite. Subgroups within each group were classified by relative size as small, medium, or large. Unitary groups were statistically similar to the larger subgroups in bi- and tripartite groups, but differed from smaller subgroups in sex ratio, juvenile membership, and relation to the substrate. While subdivision of groups could, in theory, be explained by proximity among randomly dispersed aggregations or by discontinuity of underlying substrate or available food, existing evidence does not favour these hypotheses. Group subdivision is probably the consequence of successive fissions of a previously unitary group.     

The different effects of an epoxy and a methylene group on enzymic reductions of a vicinal oxo group

In the case of two 3-hydroxysteroid dehydrogenases, 1 α,2α-epoxy-17β-hydroxy-5α-androstan-3-one was shown to be a substrate, whereas 17β-hydroxy-1 α,2α-methylene-5α-androstan-3-one scarcely served as a substrate and was an inhibitor. This is unlikely to be a simple steric effect, but its electronic basis is not clear.