The phylogenetic position of toadfishes (order Batrachoidiformes) in the higher ray-finned fish as inferred from partitioned Bayesian analysis of 102 whole mitochondrial genome sequences

In a previous study based on 100 whole mitochondrial genome (mitogenome) sequences, we sought to provide a new perspective on the ordinal relationships of higher ray-finned fish (Actinopterygii). The study left unexplored the phylogenetic position of toadfishes (order Batrachoidiformes), as data were unavailable owing to technical difficulties. In the present study, we successfully determined mitogenomic sequences for two toadfish species ( Batrachomoeus trispinosus and Porichthys myriaster ) and found that the difficulties resulted from unusual gene arrangements and associated repetitive non-coding sequences. Unambiguously aligned, concatenated mitogenomic sequences (13 461 bp) from 102 higher actinopterygians (excluding the ND6 gene and control region) were divided into five partitions (1st, 2nd and 3rd codon positions of the protein-coding genes, tRNA genes and rRNA genes) and partitioned Bayesian analyses were conducted. The resultant phylogenies strongly suggest that the toadfishes are not members of relatively primitive higher actinopterygians (Paracanthopterygii), but belong to a crown group of actinopterygians (Percomorpha), as was demonstrated for ophidiiform eels (Ophidiiformes) and anglerfishes (Lophiiformes) in the previous study. We propose revised limits of major unranked categories for higher actinopterygians and a new name (Berycomorpha) for a clade comprising two reciprocally paraphyletic orders (Beryciformes and Stephanoberyciformes) based on the present mitogenomic phylogenies.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 289–306.     

A role for oxalic acid generation in ozone‐induced signallization in Arabidopis cells

Ozone (O₃) is an air pollutant with an impact increasingly important in our industrialized world. It affects human health and productivity in various crops. We provide the evidences that treatment of Arabidopsis thaliana with O₃ results in ascorbate‐derived oxalic acid production. Using cultured cells of A. thaliana as a model, here we further showed that oxalic acid induces activation of anion channels that trigger depolarization of the cell, increase in cytosolic Ca²⁺ concentration, generation of reactive oxygen species and cell death. We confirmed that O₃ reacts with ascorbate in the culture, thus resulting in production of oxalic acid and this could be part of the O₃‐induced signalling pathways that trigger programmed cell death.     

Dopamine influences locomotor activity in honeybee queens: implications for a behavioural change after mating

Abstract Dopamine has been suggested to be involved in physiological and/or behavioural changes triggered by mating in European honeybee (Apis mellifera) queens but its specific role remains unclear. In the present study, the amounts of dopamine (DA) and its metabolite, N‐acetyldopamine (NADA) are measured, in queens of various ages to clarify the association with locomotor activity. The effects of DA receptor agonist/antagonist drugs on locomotor activity are further investigated. Brain levels of DA and NADA are relatively constant during the period before mating when locomotor activity reportedly increases with age but decreases in 1‐year‐old laying queens with low locomotor activity. Reduced DA and NADA levels are also found in haemolymph of 1–3‐month‐old laying queens. When a DA receptor agonist or antagonist is injected into 6‐day‐old virgin queens, locomotor activity levels increase significantly with 2‐amino‐6,7‐dihydroxy‐1,2,3,4‐tetrahydronaphthalene (agonist), and decreased with cis(Z)‐flupenthixol (antagonist). These results suggest that DA systems are involved in the motor control of honeybee queens, and that the decline in DA levels reduces locomotor activity after mating but increased locomotor activity before mating may be independent of DA levels.     

High temperature causes arrest of cell cycle in G2 phase in BmN cells derived from the silkworm, Bombyx mori

Abstract.  The influence of temperature on the insect cell line, BmN, derived from the silkworm, Bombyx mori is investigated. These cells proliferate at an accelerated pace as the temperature increases from 22 to 30 °C, but the growth rate slows at 34 °C, and proliferation stops at 38 °C. At high temperatures, abnormal cellular morphology is observed. Cells treated at 38 °C have cytoplasmic bilateral protrusions and they gradually aggregate and float in the medium. BmN cells without proliferation at 38 °C are viable but have reduced DNA synthesis. At high temperatures, the cell cycle of BmN cells halts at the G₂ phase. After heat treatment of the larvae, an accumulation of larval haemocytes with high DNA content is found, which suggests that the cell cycle arrest at G₂ also occurs in the silkworm at high temperatures.     

LABORATORY OBSERVATIONS ON THE EARLY LIFE STAGES OF THE DIAMOND SQUID THYSANOTEUTHIS RHOMBUS

The early life stages of the diamond squid Thysanoteuthis rhombusfrom early embryogenesis to post-hatching (0–7 days old)were observed through laboratory incubation using egg massescollected in the southern Sea of Japan. The egg diameter andmantle length increased during embryonic development throughhatching. Mantle-length growth was linear over time, and thegrowth rate was significantly higher at 25°C than at 20°C.The inner yolk was located on the dorsal side of the mantlecavity and increased in volume through hatching. Immediatelyafter they hatched, the hatchlings remained on the bottom ofculture plates with their ventral sides facing up, but 2–3days after hatching they began to swim with their dorsal sidesfacing up. Feeding experiments were conducted, but none of thehatchlings fed. Statolith growth increments were shown to formdaily. Ontogenetic changes that occur from fertilization throughpost-hatching are discussed. (Received 8 June 2005; accepted 2 November 2005)     

Quantitative trait loci controlling aluminium tolerance in two accessions of Arabidopsis thaliana (Landsberg erecta and Cape Verde Islands)

Quantitative trait loci (QTL) analysis of aluminium (Al) tolerance was performed using Ler/Cvi recombinant inbred (RI) lines of Arabidopsis thaliana. Relative root length (RRL) (root length with 4 µm Al/root length with no Al at pH 5.0) on day 5 was used as the Al tolerance index for QTL analysis. Al tolerance judged by RRL was well correlated to tolerance judged by other indexes, including accumulation of callose, reactive oxygen species in the root apex and growth performance on acid soil containing a large amount of exchangeable Al. Using data sets with an h_b² of 0.91, two QTLs were detected at the top of chromosome 1 and bottom of chromosome 3. These QTLs explained 40 and 16% of the phenotypic variation of Al tolerance, respectively, and the positive effect of the Cvi allele. The QTL on chromosome 1 overlapped with a major QTL in another recombinant inbred population, and is possibly related to malate excretion. A complete pair-wise search revealed 11 sets of epistatic interacting loci pairs, which accounted for the transgressive segregation among the RI population. Several epistatic interactions shared the same chromosomal region, indicating the possible involvement of regulatory proteins in Al tolerance in Arabidopsis.     

Non-cyclic photophosphorylation by spinach grana treated with 0.8 M Tris buffer

1. Photophosphorylation was measured with spinach grana sampleswashed by 0.8 M Tris buffer at pH 8.0, which no longer catalyzedthe ferricyanide and NADP HILL reactions with water as the electrondonor. The photophosphorylation with the reaction mixture containing2 10^–4 M 2,6-dichlorophenol indophenol (DCPI) plus above2 10^–3 M ascorbate as the electron donor system insteadof water under anaerobic conditions was, in the most part, dependenton the addition of both PPNR (a nonheme iron protein requisitefor photosynthetic pyridine nucleotide reduction ; spinach ferredoxin)and NADP as the electron acceptor system. However, when ascorbateconcentration only was lowered to 2 10^–4 M, the entirephotophosphorylation proceeded, even in the absence of the electronacceptor system. 2. When the NADP added in the reaction mixture had been reducedby glucose-6-phosphate and glucose-6-phosphate dehydrogenasebefore illumination, the photophosphorylation with 2 10^–4M DCPI plus 6.7 10^–3 M ascorbate decreased to aboutthe same rate as that obtained without NADP. 3. The time course for photophosphorylation in the presenceof NADP was consistent with the time course for the photoreductionof NADP: On the complete reduction of NADP, the photophosphorylationstopped. 4. In the presence of 6.7 10^–3 M dichloropheny 1.1,1-dimethylureaor 3 10^–4 M o-phenanthroline, non-cyclic photophosphorylationwith 2 10^–4 M DCPI plus 6.7 10^–3 M ascorbateas the electron donor system decreased to about half that ofthe control, and the remaining activities were hardly affectedeven at higher concentrations of both inhibitors. The P/2e^–ratios of non-cyclic photophosphorylation in the absence andpresence of ophenanthroline were 0.74 and 0.48, respectively. ¹Present address: Department of Biology, University of California,San Diego, La Jolla, California 92037, U. S. A.     

Reactivation of the Hill reaction of Tris-washed chloroplasts

The Hill reaction of chloroplasts was inhibited by washing themwith 0.8 M Tris buffer. This inhibition was further promotedby adding ferricyanide in the washing medium. When a reducingreagent, such as the 2,6-dichlorophenol indophenol (DCPIP)-ascorbatesystem or the hydroquinone (HQJ-ascorbate system, had been addedto the Tris buffer, Hill reaction activity was unaffected. Hill reaction activity of Tris-washed chloroplasts recoveredup to 70% of the initial level by re-washing the chloroplastswith a preparation medium containing theabove reducing reagents. Photobleaching of carotenoid and chlorophyll is characteristicof Tris-washed chloroplasts. However, reactivated chloroplastsshowed no photobleaching as in the case with intact chloroplasts. (Received April 20, 1970; )