La formule chromosomique chez cinq espèces de Chiroptères

Summary Five species ofChiroptera were studied and the following numbers were found:Rhinolophus hipposideros Bechst.N=27;Barbastella barbastellus Schr.N=16;Plecotus auritus L.N=16;Myotis myotis Bork.N=21;Miniopterus schreibersii Kuhl,N=23. Centric fusions occur in the chromosomal evolution ofChiroptera. Sex-chromosomes ofX-Y type.     

Comparative aspects of structure and action of molluscan neuropeptides

A number of neuropeptides were isolated from the ganglia and muscles of molluscs, and their actions were examined. Diverse neuropeptides, in addition to several classical neurotransmitters, were suggested to be involved in the regulation of the anterior byssus retractor muscle ofMytilus. A wide structural variety of members of theMytilus inhibitory peptide family was observed in each of the generaMytilus, Achatina andHelix. Gly-Trp-NH₂, the C-terminal dipeptide fragment of the neuropeptide AGPWamide, showed a more potent action than the parent peptide in all of the muscles examined. Peptides related to some molluscan neuropeptides were found to be distributed interphyletically. Some neuropeptides containing ad-amino acid residue were found inAchatina andMytilus. These aspects of molluscan neuropeptides are thought not to be exceptional.     

Studies on the thyroid in transgenic mice expressing the genes for human and bovine growth hormone

Summary The thyroid glands of transgenic mice (TM) expressing the genes for human (h) and bovine (b) growth hormone (GH) were studied. The percentages of larger follicles inhGH TM of either sex were significantly greater than in the corresponding normal littermates, and follicles ranging up to 350 m in diameter were present in malehGH TM. In contrast, thyroid follicles were only slightly enlarged in malebGH TM, and were unchanged in femalebGH TM. The serum concentrations of T4 were significantly decreased in malebGH TM and not altered in the other groups. Serum concentrations of T3 were slightly, but significantly increased in femalehGH TM and femalebGH TM, but were unaffected in male TM of either type. Since the principal difference between these foreign GHs in rodents is the additional lactogenic activity of human GH, these results may indicate that the effects of prolactin can influence the development of the thyroid.     

Mitochondrial DNA variation in social wasps (Hymenoptera,Vespidae)

Summary Patterns of restriction fragment length polymorphisms (RFLP) of European Vespinae were more similar within genera than between them. Distance trees were constructed that support the hypothesis of monophyly of the generaVespula andDolichovespula. Within the genusVespula, V. germanica was more closely related toV. rufa than toV. vulgaris. The position of the genusVespa remained uncertain due to the precision limits of the RFLP technique.     

Gel-electrophoretic description of European populations ofTerellia virens (Loew) (Diptera,Tephritidae); implications for its use as an agent for the biological control ofCentaurea spp. (Asteraceae) in North America

Allozyme frequencies of 15 enzyme loci, 14 of which were polymorphic, were used to characterize sevenTerellia virens populations originating from three allopatrically distributedCentaurea species. The two populations whose origins were geographically furthest apart, from Israel (onC. iberica) and from Switzerland (onC. vallesiaca), showed relatively high values of genetic distance from the 5 populations sampled in Austria and Hungary (onC. maculosa) (Nei's D>0.07). The latter five displayed a high degree of genetic similarity. No diagnostic (fixed) allelic differences were observed between these three groups ofT. virens populations, but they could be well characterized by significant differences in allelic frequencies at 9 enzyme loci. Independently of this study, the populations from Switzerland (C. vallesiaca) and eastern Austria (C. maculosa) were selected as potential source populations for future introductions into North America for the biological control of introducedC. maculosa andC. diffusa. Based on the observed genetic differences and results from field experiments on the host specificity of these two potential source populations, it is argued that host specificity screening tests should be conducted separately for local (host plant) populations, as such populations might accept a different set of hosts. Biotype mismatch and the risk of spill-overs to native species could thus possibly be reduced.     

Growth inhibitory,insecticidal and antifeedant effects of some antileukemic and cytotoxic quassinoids on two species of agricultural pests

Summary Several quassinoids, obtained by isolation and derivatization fromSimaba multiflora andSoulamea soulameoides, were evaluated for growth inhibitory and insecticidal effects against the tobacco budworm (Heliothis virescens) and for antifeedant effects againstH. virescens and the fall armyworm (Spodoptera frugiperda). The relative activity of the quassinoids as insect growth inhibitors generally paralleled their known relative potency as antileukemic and cytotoxic agents.Phytochemical aspects of this work were supported by Contract CM-97295 with the Division of Cancer Treatment, National Cancer Institute, National Institutes of Health, Bethesda, Md. Insects were kindly supplied by the agency of the United States Department of Agriculture at Brownsville, TX.     

On the specific attraction of the males of the six-toothed spruce bark beetle,Pityogenes chalcographus (L.) to a mixture of synthetic pheromones of the eight-toothed spruce bark beetle,Ips typographus (L.) (Coleoptera,Scolytidae)

Summary Traps containing a mixture of attractants forIps typographus also caught other species of bark beetles. The numbers ofPityogenes chalcographus, Pityogenes conjunctus, andTrypodendron lineatum were too high to be interpreted as accidental captures. The males of the polygamousP. chalcographus were specifically attracted, indicating that theI. typographus pheromone or one of its components acts as a kairomone and primary attractant for the pioneering males ofP. chalcographus.     

The effect of X-rays and EMS on the behavior of the transposing element,TE98, inDrosophila melanogaster

Summary The sensitivity of TE98 (carryingw ^+R andrst ⁺) to X-rays does not differ significantly from the mutability ofcurled andkarmoisin loci. In addition no spontaneous mutants of TE98 were recovered, indicating its extreme stability. On the effect of EMS nowhite mutants were found supporting the view that thew ⁺ gene of TE98 is duplicated.     

Effect of acetylcholine on melanophores ofRana tigrina

Summary Acetylcholine produced melanin aggregation and blanching of skin colour inRana tigrina, the common Indian frog. The effects were more prolonged in frogs pretreated with an anticholinesterase agent. Acetylcholine effects were not antagonized by eitherm-cholinolytic (atropine) orn-cholinolytic (pentolinium) agents, but were markedly inhibited by procaine. The results have been discussed in the light of the well-known membrane-stabilizing effect of procaine.     

Intergeneric interactions betweenEimeria separata (Apicomplexa) andNippostrongylus brasiliensis (Nematoda) in the rat

Summary Ova production inNippostrongylus brasiliensis infected rats was significantly greater than in rats singly infected with the helminth whenEimeria separata infections were introduced 4, 6 and 11 days postinoculation withN. brasiliensis. Patent periods were unaltered during concurrent infections. These results suggest that the presence ofE. separata affects helminth fecundity but does not increaseN. brasiliensis longevity as has been shown withE. nieschulzi.This study was supported by NIH MB RS Grant RRO8012-8.     

Fluorescence replication banding of frog chromosomes

To identify individual chromosomes of a frog karyotype by their fluorescence banding patterns, chromosomes were stained with actinomycin D and 4,6-diamidino-2-phenylindole (DAPI) after incorporation of BrdU during the late S-phase. The chromosomes of three Rana species which were selected for this study (R. ridibunda, R. lessonae and R. japonica) showed well-defined late replication bands. The fluorescence patterns obtained were the reverse of those produced by a 4Na-EDTA Giemsa-staining technique. Fluorescence patterns of the two water frog species (R. ridibunda and R. lessonae) were similar to each other, except for the different fluorescence of the centromeric heterochromatin, which gave extremely bright signals in R. ridibunda but no signal in R. lessonae. Experiments also showed differences between the fluorescence patterns of R. lessonae chromosome 13 in the Italian and Luxembourgian populations. These results sho w that the fluorescence replication banding using actinomycin D and DAPI is very effective in identifying individual frog chromosomes and detecting their structural changes. Received 7 June 1996; received after revision 23 July 1996; accepted 21 August 1996     

DNG1, a Dictyostelium homologue of tumor suppressor ING1 regulates differentiation of Dictyostelium cells

dng1 is a Dictyostelium homologue of the mammalian tumor suppressor ING gene. DNG1 protein localizes in the nucleus, and has a highly conserved PHD finger domain found in chromatin-remodeling proteins. Both dng1 disruption and overexpression impaired cell proliferation. In dng1-null cells, the progression of differentiation was delayed in a cell-density-dependent manner, and many tiny aggregates were formed. Exogenously applied cAMP pulses reversed the inhibitory effect caused by dng1 disruption on the aggregation during early development, but formation of tiny aggregates was not restored. dng1-overexpressing cells acquired the ability to undergo chemotaxis to cAMP earlier and exhibited enhanced differentiation. These phenotypes were found to be coupled with altered expressions of early genes such as cAMP receptor 1 (car1) and contact site A (csA). Furthermore, disordered histone modifications were demonstrated in dng1-null cells. These results suggest a regulatory role of dng1 in the transition of cells from growth to differentiation.Received 29 December 2004; received after revision 24 May 2005; accepted 26 May 2005     

Phenological studies of selected savanna mosses of south-western Nigeria

It was established that there is little diversity of bryophytes in the derived savanna. Mosses were found in the sampling sites, whereas liverworts were rarely observed. The reproductive methods of four dominant sexually reproducing savanna mosses —Archidium ohioense, Bryum coronatum, Fissidens minutifolius andTrachycarpidium tisserantii were monitored over two consecutive rainy seasons. Protonemal and gametophyte production were noticed in the field in March/April, and capsule dehiscence and spore dispersal occurred in September/October. The sequential stages of development, starting with gametangial production and ending with the falling of the dehisced capsules, occurred within the rainy season. However,A. ohioense andT. tisserantii did not discharge their spores easily (cleistocarpous), unlike the stegocarpous speciesB. coronatum andF. minutifolius. Water availability and possibly high humidity may have contributed to growth. The short period between sex organ formation and dehiscence of capsule seen in these studies, compared with the longer period in some temperate mosses, may be an advantage for bryophytes in a savanna environment.     

Beta-carotene affects gene expression in lungs of male and female <Emphasis Type="Italic">Bcmo1</Emphasis><Superscript>−/−</Superscript> mice in opposite directions

Molecular mechanisms triggered by high dietary beta-carotene (BC) intake in lung are largely unknown. We performed microarray gene expression analysis on lung tissue of BC supplemented beta-carotene 15,15′-monooxygenase 1 knockout (Bcmo1 ^−/−) mice, which are—like humans—able to accumulate BC. Our main observation was that the genes were regulated in an opposite direction in male and female Bcmo1 ^−/− mice by BC. The steroid biosynthetic pathway was overrepresented in BC-supplemented male Bcmo1 ^−/− mice. Testosterone levels were higher after BC supplementation only in Bcmo1 ^−/− mice, which had, unlike wild-type (Bcmo1 ^+/+) mice, large variations. We hypothesize that BC possibly affects hormone synthesis or metabolism. Since sex hormones influence lung cancer risk, these data might contribute to an explanation for the previously found increased lung cancer risk after BC supplementation (ATBC and CARET studies). Moreover, effects of BC may depend on the presence of frequent human BCMO1 polymorphisms, since these effects were not found in wild-type mice.     

Overexpression of SUMO perturbs the growth and development of <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis>

Small ubiquitin-related modifiers (SUMOs) are important regulator proteins. Caenorhabditis elegans contains a single SUMO ortholog, SMO-1, necessary for the reproduction of C. elegans. In this study, we constructed transgenic C. elegans strains expressing human SUMO-1 under the control of pan-neuronal (aex-3) or pan-muscular (myo-4) promoter and SUMO-2 under the control of myo-4 promoter. Interestingly, muscular overexpression of SUMO-1 or -2 resulted in morphological changes of the posterior part of the nematode. Movement, reproduction and aging of C. elegans were perturbed by the overexpression of SUMO-1 or -2. Genome-wide expression analyses revealed that several genes encoding components of SUMOylation pathway and ubiquitin-proteasome system were upregulated in SUMO-overexpressing nematodes. Since muscular overexpression of SMO-1 also brought up reproductive and mobility perturbations, our results imply that the phenotypes were largely due to an excess of SUMO, suggesting that a tight control of SUMO levels is important for the normal development of multicellular organisms.     

Cellulase genes from the parabasalian symbiont <Emphasis Type="Italic">Pseudotrichonympha grassii</Emphasis> in the hindgut of the wood-feeding termite <Emphasis Type="Italic">Coptotermes formosanus</Emphasis>

Cellulase genes of Pseudotrichonympha grassii (Hypermastigida: Eucomonymphidae), the symbiotic flagellate in the hindgut of the wood-feeding termite Coptotermes formosanus, were isolated and characterized. The nucleotide sequences of the major cellulase component in the hindgut of C. formosanus were determined based on its N-terminal amino acid sequence. The five isolated nucleotide sequences (PgCBH-homos) had an open reading frame of 1350 bp showing similarity to catalytic domains of glycoside hydrolase family (GHF) 7 members, and primary structure comparison with GHF7 members whose tertiary structures are well-characterized revealed the overall similarity between PgCBH-homo and the catalytic domain of a processive cellulase Cel7A (formerly CBHI) from the aerobic fungus Trichoderma reesei. Functional expression of PgCBH-homos in Escherichia coli, using the carboxymethylcellulose-Congo red assay, demonstrated the actual cellulolytic activity of PgCBH-homo. RT-PCR showed that PgCBH-homos were expressed, from the three flagellates in the hindgut, specifically in P. grassii. Received 10 July 2002; accepted 26 July 2002 RID="*" ID="*"Corresponding author.     

The origin of the brown frogs with 2n=24 chromosomes

Late replication and C-banding analyses of somatic metaphase chromosomes were attempted on three species of brown frogs with 2n=26 chromosomes (Rana japonica, R. tsushimensis andR. temporaria), and three with 2n=24 chromosomes (R. ornativentris, R. dybowskii andR. chensinensis), which are distributed in the Palearctic region. The late replication banding patterns were highly conserved in these species. Four chromosome inversions were demonstrated inR. ornativentris, two inR. dybowskii and two inR. tsushimensis. From a detailed comparison of late replication and C-banding patterns between the 2n=26 and the 2n=24 species, it was found that an end-to-end fusion of two small chromosomes (nos 11 and 13) in an ancestral 2n=26 species may have produced the medium-sized no. 6 chromosome of the 2n=24 species.     

Urochordates carry multiple genes for goose-type lysozyme and no genes for chicken- or invertebrate-type lysozymes

Genome clones and expressed sequence tags (ESTs) from the ascidian Ciona intestinalis and from the larvacean Oikopleura dioica were analysed for the presence of lysozyme-encoding genes. Two genes were found to potentially code for goose-type lysozymes in Oikopleura, while three or possibly more g-type proteins form the lysozyme complement of C. intestinalis, and at least one of these genes from each species is expressed based on EST data. No genes for chicken- or invertebrate-type lysozymes were found in either urochordate species. Consistent with this finding, extracts of Oikopleura animals possessed hydrolysing activity on bacterial cell walls, and this activity was not inhibited in the presence of a known inhibitor of chicken-type lysozyme. A wide range of isoelectric points for the predicted lysozymes from Ciona (pI 4.4, 6.4 and 9.9) and from Oikopleura (pI 5.0 and 8.0) suggests tissue-specific adaptations as well as specific functional roles of the lysozymes. Comparisons of gene structures, encoded sequences, cysteine residue content and their positions in the proteins indicate that the g-type lysozymes of Ciona intestinalis are more closely related to those of vertebrates than are the g-type lysozymes of Oikopleura. Multiple genes from each species may result from separate and lineage-specific duplications followed by functional specialisation.Received 29 June 2003; received after revision 24 July 2003; accepted 29 July 2003     

The syntheses of spin labelled juvenoids

Summary 5 juvenoids labelled with stable nitroxyl radicals were synthesized and were shown to have morphogenetic effect onTenebrio molitor L. andDysdercus cingulatus.     

Cytogenetic studies of Hynobiidae (Urodela). IX. Karyological characteristics ofHynobius abei Sato by means of R-and C-banding

Summary Chromosomal characteristics of the salamander speciesHynobius abei, from Ohimya (Kyoto) were revealed by the techniques of R-and C-banding. The karyotype ofH. abei was characterized by the shortness of an R-negative (C-positive) band in the terminal region of the long arm of chromosome 2 and a band encompassing the whole short arm of chromosome 10. These two bands inH. abei were the shortest among those of the variousHynobius species that have been examined. Otherwise no differences could be detected betweenH. abei and seven other pond-type species ofHynobius (2n=56) in terms of the banding patterns of 18 specifically identifiable pairs of their chromosomes.