Epigamic selection by males as evidenced by courtship partner preferences in the checkered white butterfly (Pieris protodice)

Free-flying males of the checkered white butterfly, Pieris protodice, were presented with tethered females that varied with respect to both size (as measured by forewing length) and age (as measured by wing wear). Because males make a substantial investment in their offspring through nutrients passed to the female during copulation, they were expected to court young and large females for longer times than older and smaller females, and they did so. Additional experiments further suggest that size discriminations are made on the basis of apparent wing area and age discriminations are made on the basis of an age-related increase in ultraviolet reflectance that occurs in females. The discussion examines the adaptive value of these discriminations.     

An Ecteola-cellulose chromatography assay for 3′-phosphoadenosine 5′-phosphosulfate: Phenol sulfotransferase

A new assay procedure for phenol sulfotransferase which employs [35S]-3'-phosphoadenosine-5'-phosphosulfate as a sulfate donor and a variety of phenols as sulfate acceptors was developed. The appearance of the 35S-sulfated products or the disappearance of the [35S]-3'-phosphoadenosine-5'-phosphosulfate are determined simultaneously by chromatography of the assay incubation mixtures on Ecteola-cellulose columns, eluting with an NH4HCO3 step gradient. Various acidic, neutral, and basic phenols can be employed as substrates for phenol sulfotransferase using this procedure.     

A single succinic semialdehyde dehydrogenase is involved in 4-hydroxyphenylacetate and 4-aminobutyrate catabolism in Klebsiella pneumoniae M5a1

Abstract Klebsiella pneumoniae M5a1 grows readily on two compounds, 4-hydroxyphenylacetate and 4-aminobutyrate, whose catabolism produces succinic semialdehyde. A single succinic semialdehyde dehydrogenase was detected, native molecular weight 52000, that has NAD as the preferred cofactor and is induced by succinic semialdehyde functions in the oxidation of succinic semialdehyde during growth on both 4-hydroxyphenyl-acetate and 4-aminobutyrate. This contrasts with the situation for Escherichia coli and Pseudomonas putida where two distinct forms of succinic semialdehyde dehydrogenase have been observed.     

Enzymes of cyclic nucleotide degradation in eye tissues during experimental ocular herpes

Activity of phosphodiesterases disintegrating cAMP and cGMP in the cornea, sclera and ciliary body was investigated in health and in different stages of experimental herpetic keratitis. The problems concerning the role of the cyclase system in the pathogenesis of herpetic keratitis and the possibility of applying some of the drugs to the disease treatment are discussed.     

Fluorimetric determination of carbamoyl phosphate

A simple fluorimetric assay for the determination of carbamoyl phosphate in tissue extracts is described. In the assay, production of ATP from carbamoyl phosphate and ADP by carbamate kinase is coupled to the formation of NADPH, using glucose, hexokinase, NADP⁺, and glucose-6-phosphate dehydrogenase. Production of NADPH in this system proved to be equal to the amount of carbamoyl phosphate present.     

A- and B-type lamins are differentially expressed in normal human tissues

 A selection of normal human tissues was investigated for the presence of lamins B1, B2, and A-type lamins, using a panel of antibodies specific for the individual lamin subtypes. By use of immunoprecipitation and two-dimensional immunoblotting techniques we demonstrated that these antibodies do not cross-react with other lamin subtypes and that a range of different phosphorylation isoforms is recognized by each antibody. The lamin B2 antibodies appeared to decorate the nuclear lamina in all tissues examined, except hepatocytes, in which very little lamin B2 expression was observed. In contrast to previous studies, which suggested the ubiquitous expression of lamin B1 in mammalian tissues, we show that lamin B1 is not as universally distributed throughout normal human tissues as was to be expected from previous studies. Muscle and connective tissues are negative, while in epithelial cells lamin B1 seemed to be preferentially detected in proliferating cells. These results correspond well with those obtained for lamin B1 in chicken tissues. The expression of A-type lamins is most prominent in well-differentiated epithelial cells. Relatively undifferentiated and proliferating cells in epithelia showed a clearly reduced expression of A-type lamins. Furthermore, most cells of neuroendocrine origin as well as most hematopoietic cells were negative for A-type lamin antibodies. Accepted: 4 February 1997