New species and records of the genera Milichia Meigen and Milichiella Giglio‐Tos (Diptera,Milichiidae) from the Oriental region and Seram Island

The species of the genera Milichia and Milichiella in the Oriental region and Seram Is. are taxonomically investigated. Three new species, Milichia linealis sp. nov. from the Philippines, Milichiella sulawesiensis sp. nov. and Milichiella nigella sp. nov. from Indonesia, are described. New distributional data of Milichiella bakeri Aldrich from Indonesia and M. spinthera Hendel from Indonesia, Nepal and Thailand are given. Keys to the species of Milichia and Milichiella in the Oriental region and Seram Is. are provided.     

The major carotenoid in all known species of heliobacteria is the C30 carotenoid 4,4′-diaponeurosporene, not neurosporene

The carotenoids of five species of heliobacteria (Heliobacillus mobilis, Heliophilum fasciatum, Heliobacterium chlorum, Heliobacterium modesticaldum, and Heliobacterium gestii) were examined by spectroscopic methods, and the C₃₀ carotene 4,4′-diaponeurosporene was found to be the dominant pigment; heliobacteria were previously thought to contain the C₄₀ carotenoid neurosporene. In addition, trace amounts of the C₃₀ diapocarotenes diapolycopene, diapo-ζ-carotene, diapophytofluene, and diapophytoene were also found. Up to now, diapocarotenes have been found in only three species of chemoorganotrophic bacteria, but not in phototropic organisms. Furthermore, the esterifying alcohol of bacteriochlorophyll g from all known species of heliobacteria was determined to be farnesol (C₁₅) instead of the usual phytol (C₂₀). Heliobacteria may be unable to produce geranylgeranyol (C₂₀). Received: 10 March 1997 / Accepted: 3 June 1997     

Notes on two species of the subgenus Lyrothorax Chaudoir (Coleoptera: Carabidae; genus Pterostichus), Pterostichus amagisanus Tanaka and Ishida and Pterostichus fujitai Tanaka and Ishida

Two species of the subgenus Lyrothorax Chaudoir (Coleoptera: Carabidae; genus Pterostichus ), Pterostichus amagisanus Tanaka and Ishida and Pterostichus fujitai Tanaka and Ishida, were revised based on the male endophallus (inner sac everted from aedeagus). P. amagisanus was newly recorded based on a single male from Kyushu, southwest Japan, far from its known distribution (Honshu; the Fuji-Hakone-Izu volcano area), although additional materials are necessary to confirm this record. Despite a highly disjunct distribution, no conspicuous difference was recognized in either external or genital characters between the materials from Honshu and Kyushu. The nominal species P. fujitai was separated into two species, P. fujitai (Honshu) and Pterostichus eoyoritomus sp. nov. (Shikoku; type locality: Mount Jingayama); these two species have some significant differences in the endophallic structures. Character states in male genitalia suggest a sister relationship between P. eoyoritomus sp. nov. and Pterostichus yoritomus Bates.     

Multiple nutritional phenotypes of fission yeast mutants defective in genes encoding essential mitochondrial proteins

Mitochondria are essential for regulation of cellular respiration, energy production, small molecule metabolism, anti-oxidation and cell ageing, among other things. While the mitochondrial genome contains a small number of protein-coding genes, the great majority of mitochondrial proteins are encoded by chromosomal genes. In the fission yeast Schizosaccharomyces pombe, 770 proteins encoded by chromosomal genes are located in mitochondria. Of these, 195 proteins, many of which are implicated in translation and transport, are absolutely essential for viability. We isolated and characterized eight temperature-sensitive (ts) strains with mutations in essential mitochondrial proteins. Interestingly, they are also sensitive to limited nutrition (glucose and/or nitrogen), producing low-glucose-sensitive and ‘super-housekeeping'' phenotypes. They fail to produce colonies under low-glucose conditions at the permissive temperature or lose cell viability under nitrogen starvation at the restrictive temperature. The majority of these ts mitochondrial mutations may cause defects of gene expression in the mitochondrial genome. mrp4 and mrp17 are defective in mitochondrial ribosomal proteins. ppr3 is defective in rRNA expression, and trz2 and vrs2 are defective in tRNA maturation. This study promises potentially large dividends because mitochondrial quiescent functions are vital for human brain and muscle, and also for longevity.     

18,19-Dihydroxydeoxycorticosterone; A novel product of cytochrome P-45011β-catalyzed reaction

After incubating 18-hydroxydeoxycorticosterone (18-OH-DOC) with cytochrome P-450_11β in the reconstituted system, the products were analyzed with HPLC. There appeared two product-peaks on the chromatogram, one of which was identified as a peak of 18-hydroxycorticosterone (18-OH-B), an expected product of the 11β-hydroxylation. Another peak did not coincide with those of any known corticoids. This unidentified product was further purified, and the purified material was analyzed by gas chromatography-mass spectrometry ($\text{GC}\text{MS}$). The mass spectrum showed that the unidentified product is one of the structural isomers of 18-OH-B. A further analysis with ¹H-NMR spectrometry indicated that a proton resonance peak of 19-CH₃ in 18-OH-DOC disappeared in the product and the methyl group of the substrate seemed to be converted to -CH₂OH. These results suggested that the unidentified product generated from 18-OH-DOC by P-450_11β-linked hydroxylase system may be 18,19-dihydroxydeoxycorticosterone (18,19,21-trihydroxypregn-4-ene-3,20-dione; 18,19-diOH-DOC), a hitherto unreported corticoid.     

Phylogeny of ground beetles subgenus Nialoe (s. lat.) Tanaka (Coleoptera: Carabidae; genus Pterostichus): A molecular phylogenetic approach

We constructed a phylogeny of the ground beetle subgenus Nialoe ( s. lat. ), genus Pterostichus (Coleoptera: Carabidae) based on two mitochondrial (cytochrome oxidase I and 16S ribosomal DNA) and one nuclear (28S ribosomal DNA) gene sequences. Thirty-three representative species of the group and three outgroup species were analyzed. The resultant trees (maximum parsimonious, maximum likelihood and Bayesian trees of the combined data of the three gene sequences) indicated that there are two large and three small lineages in the group, some of which were supported by a previous morphology-based phylogeny. In all the analyses, the small lineage composed of two Korean species is sister to the rest of the subgenus, but relationships of other four lineages differed among the analyses and remained unresolved. The implications of the present results are discussed in terms of taxonomy and biogeography of the group.     

Curing the Megaplasmid pTT27 from Thermus thermophilus HB27 and Maintaining Exogenous Plasmids in the Plasmid-Free Strain

Stepwise deletions in the only plasmid in Thermus thermophilus HB27, megaplasmid pTT27, showed that two distantly located loci were important for maintenance of the plasmid. One is a minimum replicon including one gene, repT, coding a replication initiator, and the other encodes subunits of class I ribonucleotide reductase (RNR) for deoxynucleoside triphosphate (dNTP) synthesis. Since the initiator protein, RepT, bound to direct repeats downstream from its own gene, it was speculated that a more-downstream A+T-rich region, which was critical for replication ability, could be unwound for replication initiation. On the other hand, the class I RNR is not necessarily essential for cell growth, as evidenced by the generation of the plasmid-free strain by the loss of pTT27. However, the plasmid-free strain culture has fewer viable cells than the wild-type culture, probably due to a dNTP pool imbalance in the cell. This is because of the introduction of the class I RNR genes or the supplementation of 5′-deoxyadenosylcobalamin, which stimulated class II RNR encoded in the chromosome, resolved the decrease in the number of viable cells in the plasmid-free strain. Likewise, these treatments dramatically enhanced the efficiency of transformation by exogenous plasmids and the stability of the plasmids in the strain. Therefore, the class I RNR would enable the stable maintenance of plasmids, including pTT27, as a result of genome replication normalized by reversing the dNTP pool imbalance. The generation of this plasmid-free strain with great natural competence and its analysis in regard to exogenous plasmid maintenance will expand the availability of HB27 for thermophilic cell factories.     

Minifascicular neuropathy: a new concept of the human disease caused by desert hedgehog gene mutation.

We recently found a patient with 46,XY partial gonadal dysgenesis who presented with polyneuropathy. Sural nerve pathology revealed peculiar findings characterized by extensive minifascicular formation and with a decreased density of myelinated fibers. We found in the patient, a homozygous missense mutation at the initiating codon in exon 1 of the desert hedgehog (DHH) gene, which predicts a failure of translation of the gene. These data demonstrate that DHH is a key molecule in both male gonadal differentiation and perineurial formation in peripheral nerves.