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.     

Seed Storage Glutelin α-2 Subunit Lacking Mutants in Rice

Nine rice Oryza sativa L.） mutant lines lacking the seed storage glutelin α-2 subunit were obtained from the progenies of fertilized egg cells treated with N-methy-N-nitrosourea (MNU). The mutants could be classified into three types: the α-1 subunit increased type (α-1H/α-2L), decreased the β-2 subunit decreased type (β-2L/α-2L) and the α-3 subunit increased type (α-3H/α-2L) according to their SDS-PAGE profiles. Two-dimensional electrophoresis analysis revealed that all of the mutants lacked a polypeptide of pI 6.71/α-2, while new polypeptides of pI 6.50/α-1 and pI 6.90/α-3 formed in α-1H/α-2L and α-3H/α-2L mutants respectively. Although the β-2L/α-2L mutants did not form new polypeptide, their pI 8.74/β-2 polypeptide was also decreased, suggesting that the two polypeptides decreased in β-2L/α-2L mutants might derive from the same glutelin precursor. These mutant lines are very useful in studying genetic characterisation,the mechanism of genetic regulation on biosynthesis, gene function and proteomics of rice seed storage glutelin.     

Protein Synthesis in Dormant and Non-Dormant Cocklebur Seed Segments

Using the axial and cotyledonary segments of lower cocklebur (Xanthium pensylvanicum Wallr.) seeds, protein synthesis as shown by incorporation of radioactive leucine was examined in relation to their dormant status. During the first 9 h of water imbibition, the protein synthesis was higher in the dormant axes than in the non-dormant, after- ripened ones. When imbibed for more than 12 h non-dormant axes had a higher activity than dormant ones. This was also the case with the cotyledonary segments. Cyctoheximide, an inhibitor of protein synthesis, blocked protein synthesis in the axial tissue regardless of its dormant status, and thereby inhibited germination of the non-dormant seeds. In the dormant seeds, however, cycloheximide at 3 mM slightly stimulated germination without stimulating the C₂H₄ production. Based on these results, it is suggested that in cocklebur seeds there may be some proteinaceous system which is involved in the maintenance of dormancy.     

ANALYSIS OF CELL PROLIFERATION DURING EARLY EMBRYOGENESIS

Cell proliferation was examined during early embryogenesis of the newt ( Triturus pyrrhogaster ) by various methods. After the two-cell stage, at 23°C, the blastomere (cell) number per whole embryo increased logarithmically until the mid-blastula stage (for about 19 hr) and the rate of increase slowed down in and after the late blastula stage. On the other hand, the synchronous cleavage of the blastomeres at the animal pole continued for 18 hr until the twelfth cleavage (mid-blastula) and the transition from synchronous to asynchronous division occurred abruptly at and after the thirteenth cell division (late blastula). The study also showed that the presumptive neuro-ectoderm consisted mainly of cells of the fifteenth generation (G-15) at the onset of gastrulation (pigment stage).
The present study suggested that the number of ectodermal cells of the early gastrula (stage 12a) nearly doubled during gastrulation at the presumptive neuro-ectoderm. This means that most of the ectodermal cells are in G-16 at the end of gastrulation. On the other hand, both mitotic activity and the rate of cell increase gradually diminished during gastrulation in the ectoderms of both the presumptive neural and epidermal regions, and there are evidently significant differences in both activities between the neuro-ectoderm and the epidermal ectoderm after stage 13b: the epidermal ectoderm showed greater decrease in the rate of both mitotic activity and cell proliferation than the neuro-ectoderm.
These facts suggested that, whether the ectodermal cells will differentiate into neural cells or epidermal cells is determined during G-15 or G-16 in normal primary induction.     

Class Specificity of Avian and Mammalian Sera in Regards to Myogenic Cell Growth in vitro

Chick myogenic cells grew in the presence of a small amount of avian serum in a culture medium composed of Eagle's minimum essential medium (MEM) and horse serum. Mammalian sera, except for fetal bovine serum at high concentrations, could not substitute for the avian serum.
Rat myogenic cells grew in the presence of a small amount of mammalian serum in a culture medium composed of MEM and chick serum: avian sera, except for dove serum at high concentrations, could not substitute for the mammalian serum.
Serum from animals of the class from which the myoblasts were obtained was needed for cell growth. It is thus concluded that there is a class specificity among sera in regards to myogenic cell growth. The only exceptions to this hypothesis found so far were fetal bovine and dove sera.     

UV reflectance of inter-subspecific hybrid females obtained by crossing cabbage butterflies from Japan (Pieris rapae crucivora) with those from New Zealand (P. rapae rapae)

Cross-mating was performed between subspecies of cabbage butterfly Pieris rapae crucivora from Japan and P. rapae rapae from New Zealand, whose females are known to reflect and absorb ultraviolet (UV) light, respectively. In the female F ₁ hybrids UV reflectance was intermediate between the two parent females. Further, the UV reflectance was significantly higher in the female F ₁ hybrids derived from females of the New Zealand subspecies than in those derived from females of the Japanese subspecies.     

A bimodal germination response to temperature in cocklebur seeds. I. Cyanide-sensitive and cyanide-resistant respirations

Abstract. Pre-imbibed cocklebur ( Xanthium penn-sylvanicum Wallr.) seeds displayed bimodal germination-temperature responses with two optima at 8 and 33° C. Such germination responses occurred subsequent to bimodal respiration-temperature upsurges at lower and higher temperature regions. At lower temperatures, cocklebur seeds respired predominantly through a cyanide-sensitive cytochrome pathway. A rise in temperature resulted in a marked increase in flux via an alternative pathway, a propyl gallate- (PG) or benzohydroxamic-acid- (BHAM) sensitive pathway, thus resulting in an increase in the ratio of this pathway relative to the cytochrome pathway. Both an increased capacity for the alternative pathway and an increase in the ratio of this pathway to the cytochrome pathway were obtained when pre-imbibed seeds were exposed to either 8 or 33°C for a short period. The effects of low temperature were reduced as the exposure time was prolonged beyond 3d, resulting in a reduction in germination. Neither PG nor BHAM had an inhibitory effect on the chilling-induced germination, but the germination-stimulating effect of high temperatures was less pronounced in the presence of PG or BHAM. At high temperatures, on the other hand, KCN and NaN₃ were ineffective or, rather, slightly inhibited germination. It was thus concluded that low and high temperatures exert their germination-stimulating effects by an essentially similar manner which increases fluxes both via the cytochrome pathway and, especially, via the alternative pathway and, as a result, raises the ratio of the latter to the former.     

PHOTOSYNTHETIC NITRITE REDUCTASE II. FURTHER PURIFICATION AND BIOCHEMICAL PROPERTIES OF THE ENZYME

1. Further purification of photosynthetic nitrite reductase (PNiR),which catalyzes the transfer of hydrogen (or electron) fromthe photolytic system to nitrite, is reported in this paper.Chromatography on DEAE- cellulose and Sephadex gel-filtrationwere effective for the purification of PNiR.
2. PNiR could befractionated into two components. It was inferredfrom the dataobtained that one of these components is identicalwith PPNR,and the other one may probably be a hitherto unreportedflavinenzyme containing FMN as prosthetic group.
3. The propertiesof these two components of PNiR were described,and the interrelationshipbetween these catalysts and possibleintermediary carriers ofthis electron transfer system was discussed.

¹Dedicated to Prof. H. TAMIYA on the occasion of his 60th birthday.This investigation was supported by a Grant in Aid for FundamentalScientific Research from the Ministry of Education (No. 407130-1961)and a Grant in Aid for Organized Scientific Research from theMinistry of Education (No. 95037-1960), which are gratefullyacknowledged here. The authors also wish to acknowledge thatthe progress of this study was facilitated by a Grant from theKAISEI-KAI. A preliminary report on this work was read beforethe 25th Annual Meeting of the Botanical Society of Japan (1960,Osaka).