ABSTRACT
Ligands for only two human olfactory receptors are known. One of them, OR1D2, binds to Bourgeonal, a volatile chemical constituent of the fragrance of the mythical flower, Lily of the valley or Our Lady's tears, Convallaria majalis (also the national flower of Finland). OR1D2, OR1D4 and OR1D5 are three full-length olfactory receptors present in an olfactory locus in the human genome. These receptors are more than 80% identical in DNA sequences and have 108 base pair mismatches among them. Apparently, these mismatch positions show no striking pattern using computer pattern recognition tools. In an attempt to find a mathematical rule in those mismatches, we find that an L-system generated sequence can be inserted into the OR1D2 subfamily-specific star model and novel full-length olfactory receptors can be generated. This remarkable mathematical principle could be utilized for making new subfamily olfactory receptor members from any olfactory receptor subfamily. The aroma and electronic nose industry might utilize this rule in future.
Subject(s)
Algorithms , Base Pair Mismatch , Exons , Receptors, Odorant/genetics , Seminal Plasma Proteins/genetics , Aldehydes/chemistry , Base Sequence , Genomics , Humans , Molecular Sequence Data , Multigene FamilyABSTRACT
Both scanning electron microscopy (SEM) and contact mode imaging via atomic force microscopy (AFM) have been utilized to elucidate the ultrastructure of mung bean seed surfaces. The results indicate: 1) that AFM is useful in the examination of seed surface ultrastructure ex-vaccuo without the need for additional complex preparative procedures; and 2) that both the cotyledon and seed coat of different strains of mung beans bear specific ultrastructural details unique to each strain. To our knowledge, these are the first AFM images of seed surfaces.
Subject(s)
Mammals/physiology , Pheromones/physiology , Animals , Female , Male , Sebaceous Glands/metabolism , Sexual Behavior, AnimalABSTRACT
The effect of tunicamycin (TM), a nucleoside antibiotic, known to inhibit growth of a number of virus, protozoan and metazoan organisms, presumably by intervening in the glycosylation of glycoproteins, has been studied on Limnaea egg cells and rabbit erythrocytes. TM decreases the adhesion of cells in Limnaea morula and, apparently, induces a high degree of membrane permeability probably leading to the extrusion of cytoplasmic material. The effect of TM is more specific on mature rabbit erythrocytes which have no subcellular structure. TM treatment in vitro alters the normal bioconcave disc-shaped erythrocytes successively into crenated discs, crenated spheres, and smooth spheres. This type of transformation is known to be caused by a number of substances but the present report is the first to indicate a nucleoside-containing compound. This irreversible reaction may be attributed to a structural change of the cellular membrane of erythrocytes.
Subject(s)
Cleavage Stage, Ovum/drug effects , Erythrocytes/drug effects , Glucosamine/analogs & derivatives , Morula/drug effects , Snails/embryology , Tunicamycin/pharmacology , Animals , Cell Adhesion/drug effects , Cell Membrane Permeability/drug effects , Erythrocytes/cytology , Morula/cytology , RabbitsABSTRACT
Pheromones of the tiger happen to be a mixture of amines which are "fixed" by lipids. One of these, found always in all the four tigers investigated, is phenylethylamine. This may be a biochemical marker at a species level.
Subject(s)
Carnivora/physiology , Phenethylamines , Pheromones , Animals , Pheromones/physiologyABSTRACT
Cerulenin, a new antibiotic known to inhibit lipid synthesis in yeast, fungi and bacterial systems, has been tested with Limnaea embryos. In the presence of 40--50 microgram/ml cerulenin, lipid synthesis is inhibited by about 65% while RNA synthesis is inhibited by about 35% as is evident from the incorporation of 14C-acetate and 14C-uracil, respectively. In embryos treated with cerulenin, washed and returned to normal medium to which 14C-uracil was added, RNA synthesis continued normally. Such pretreatment with actinomycin, however, inhibits lipid synthesis by about 50%. Cerulenin treatment of eggs at the early morula or uncleaved stage for 30 min leads to a marked abnormality at the late veliger stage, and the embryos die before hatching. These results have been discussed in comparison with the known effects of actinomycin. As, unlike actinomycin, cerulenin has no delayed action, the present experiment offers a system for exploring the delayed effects of early transcription.
Subject(s)
Antifungal Agents/pharmacology , Cerulenin/pharmacology , Embryo, Nonmammalian/metabolism , Lipids/biosynthesis , Mollusca/metabolism , RNA/biosynthesis , Animals , Carbon Radioisotopes , Depression, Chemical , Uracil/metabolismABSTRACT
An attempt has been made to partially characterize the substance responsible for the rhythmic incorporation of 35S (inorganic sulfate) in the course of the cell cycle in early Limnaea embryos. This trichloroacetic acid (TCA) insoluble substance is partly pronase sensitive, and dissociable into two fractions after treatment with NaCl. One of these remains TCA-insoluble while the other is TCA soluble but precipitable by cetyl pyridinium chloride. Thus, unlike in some other higher organisms, the major part of the inorganic sulfate is incorporated here into a fraction which is not a single mycopolysaccharide, but is more likely to be a protein-mucopolysaccharide complex, rather like the chondromucoprotein of chick-embryo cartilage.
