Embryonic evidence uncovers convergent origins of laryngeal echolocation in bats

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Sodium/Proton Exchange in Cultured Bovine Adrenal Medullary Cells

We investigated the presence of Na+/H+ exchange in cultured bovine adrenal medullary cells. The intracellular pH in control cells measured by 5,5-dimethyl[2-14C]oxazolidine-2,4-dione was 7.13 +/- 0.02 (n = 6). Removal of Na+ from the incubation medium shifted the intracellular pH down to 6.67 +/- 0.12 (n = 6). Reintroduction of Na+ to the medium caused a rapid recovery in intracellular pH to 7.20-7.30 that was associated with an increase in uptake of 22Na+ by the cells. Both increases in intracellular pH and uptake of 22Na+ were inhibited by amiloride, an inhibitor of Na+/H+ exchange. The recovery of intracellular pH by addition of Na+ was partially inhibited by quinidine, another inhibitor of Na+/H+ exchange, but not by 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid, an anion-exchange (Cl-/HCO3-) inhibitor. Li+ could substitute for Na+ in the recovery of intracellular pH. Carbachol caused an increase in intracellular pH from 7.12 +/- 0.01 to 7.21 +/- 0.02 (n = 10). This increase in intracellular pH caused by carbachol was inhibited by amiloride. These results suggest the existence of an amiloride-sensitive Na+/H+ exchange that regulates the intracellular pH in adrenal medullary cells.     

Stored mRNA in cotyledons of Vigna unguiculata seeds: nucleotide sequence of cloned cDNA for a stored mRNA and induction of its synthesis by precocious germination

By differential hybridization screening, we previously selected a class of cDNA clones from a gt10 cDNA library that was constructed from the total poly(A)⁺ RNA of mature cowpea cotyledons (Plant Cell Physiol 31: 39–44, 1990). pSAS10, a clone of this class, hybridized with a cDNA probe complementary to poly(A)⁺ RNA from cotyledons collected 1 day after the onset of imbibition (DAI), but not with the cDNA probe from cotyledons at development stage II (13 to 15 days after flowering, DAF). pSAS10 mRNA was detectable only in cotyledons at development stage III (17 to 19 DAF) or later, and its level began to decline when seeds germinated. We have suggested that pSAS10 mRNA is likely to belong to the class of stored mRNA or the mRNA that is formed at the late stage of seed maturation, is conserved in quiescent seeds and becomes functional at the early stage of germination. We determined the nucleotide sequence of pSAS10 cDNA consisting of 459 bp and an approximately 36 bp poly(A) tract, and deduced the amino acid sequence of its product, a 10-kDa cysteine-rich polypeptide. Synthesis of pSAS10 mRNA was induced just before germination began, not only in mature seeds but also in immature seeds even at stages I (9 to 11 DAF) and II (13 to 15 DAF) if they were placed under conditions suitable for germination.     

Comparison of Two Pearl Sacs Formed in the Same Recipient Oyster with Different Genetic Background Involved in Yellow Pigmentation in <Emphasis Type="Italic">Pinctada fucata</Emphasis>

Color is one of the most important factors determining the commercial value of pearls. Pinctada fucata is a well-known pearl oyster producing high-quality Akoya pearls. Phenotypic variation in amount of yellow pigmentation produces white and yellowish pearls. It has been reported that polymorphism of yellow pigmentation of Akoya pearls is genetically regulated, but the responsible gene(s) has remained unknown. Here, we prepared pearl sac pairs formed in the same recipient oyster but coming from donor oysters that differ in their color. These two pearl sacs produced pearls with different yellowness even in the same recipient oyster. Yellow tone of produced pearls was consistent with shell nacre color of donor oysters from which mantle grafts were prepared, indicating that donor oysters strongly contribute to the yellow coloration of Akoya pearls. We also conducted comparative RNA-seq analysis and retrieved several candidate genes involved in the pearl coloration. Whole gene expression patterns of pair sacs were not grouped by pearl color they produced, but grouped by recipient oysters in which they were grown, suggesting that the number of genes involved in the yellow coloration is quite small, and that recipient oyster affects gene expression of the majority of genes in the pearl sac.     

Microbial desulfurization of dibenzothiophene in the presence of hydrocarbon

The bacterium, Rhodococcus erythropolis H-2, which can utilize dibenzothiophene (DBT) as a sole source of sulfur in the presence of hydrocarbon, was isolated from soil samples. When this strain was cultivated in a medium containing 0.27 mM DBT and 40% n-tetradecane, DBT was metabolized stoichiometrically to 2-hydroxybiphenyl within 1 day. This strain grew in the presence of n-octane and longer-carbonchain hydrocarbons, but not with n-hexane, styrene, p-xylene, cyclooctane or toluene. DBT degradation proceeded in the resting cell system with lyophilized cells of this strain. The addition of n-tetradecane enhanced the reaction rate, the optimal concentration being 40%. DBT degradation occurred in the reaction mixture even in the presence of 70% n-tetradecane, whereas at concentrations above 80% n-tetradecane suppressed the degradation.     

Distinct pathways for jasmonate- and elicitor-induced expressions of a cytochrome P450 gene in soybean suspension-cultured cells

The mechanisms of the jasmonate-induced expression of genes encoding the cytochrome P450 CYP93A1 and lipoxygenase L-4 were analyzed in a soybean photomixotrophic cultured cell line, SB-P. The induction of the cytochrome P450 gene caused by methyl jasmonate (MeJA) was specifically suppressed by trifluoperazine and DCMU, inhibitors of chloroplast electron transport. Additionally, induction of the cytochrome P450 gene required irradiation. In contrast, induction of the lipoxygenase L-4 gene by the MeJA treatment occurred in both dark and light. Based on the results, the presence of two distinct signalling pathways for jasmonate-inducible gene expression, light-dependent and light-independent, is proposed. The jasmonate-inducible cytochrome P450 was also specifically induced by a fungal elicitor from a cell wall fraction of Phytophthora megasperma , a fungal pathogen, suggesting a role for P450 in the defense response to fungus in soybean cells. However, trifluoperazine did not block the elicitor-induced expression of cytochrome P450.     

The photochemistry of thiophene S-oxides.

Thiophene S-oxides have been prepared and their photoreactivity has been studied. In many cases, the sulfur moiety of the thiophene S-oxides is deoxygenated. Here, the corresponding thiophenes or hydroxylated thiophenes are isolated. In the case of the photoirradiation of tert-butyl substituted thiophene S-oxides, the oxygen of the sulfoxy unit is incorporated into the heterocyclic ring system and the corresponding furans have been isolated. Also, structures with two thiophene cores have been oxidized to the respective thiophene S-oxides. These molecules undergo photodeoxygenation, a reaction, which is catalysed by (non-oxidized) thiophenes.     

Successful retrograde transport of fluorescent latex nanospheres in the cerebral cortex of the macaque monkey.

Retrograde axonal transport of latex nanospheres offers a means of delivering chemical agents to a targeted region of the central nervous system (CNS). In this study we performed microinjections of latex nanospheres into the cerebral cortex of cynomolgus monkeys and observed successful retrograde labeling of neurons in the contralateral region. Our data indicate the successful use of this delivery system, reported in studies using other animals, may also be achievable with primates as well.