Meiotic behaviour of sex chromosomes and polymeiosis in three species of insectivores

A study of male meiosis has been carried out on air-dried testicular preparations from three insectivore species: Crocidura russula, Neomys anomalus and Talpa occidentalis.Two particularities in relation to the meiotic process were found. The sex-chromosomes show a special allocycly. In the zygotene and pachytene stages, only some cells (a maximum of 50% in some individuals) present a typical sex-vesicle. In the majority of cells in these stages, the X-chromosome appears unfolded, isopycnotic or negatively heteropycnotic, with the ends of the arms together. The Y-chromosome is more condensed and it is associated with the ends of the X-chromosome. At diakinesis and metaphase I the sex chromosomes show end-to-end pairing. A second interesting feature in these species is the existence of spontaneous polymeiosis in a relative high frequency.The origin of this phenomenon, and the influence of these two particularities on fertility and the relation with the phylogeny of these species are discussed.     

Fissions,fusions, and translocations shaped the karyotype and multiple sex chromosome constitution of the northeast‐Asian wood white butterfly,Leptidea amurensis

Previous studies have shown a dynamic karyotype evolution and the presence of complex sex chromosome systems in three cryptic Leptidea species from the Western Palearctic. To further explore the chromosomal particularities of Leptidea butterflies, we examined the karyotype of an Eastern Palearctic species, Leptidea amurensis. We found a high number of chromosomes that differed between the sexes and slightly varied in females (i.e. 2n = 118–119 in females and 2n = 122 in males). The analysis of female meiotic chromosomes revealed multiple sex chromosomes with three W and six Z chromosomes. The curious sex chromosome constitution [i.e. W_1–3/Z_1–6 (females) and Z_1–6/Z_1–6 (males)] and the observed heterozygotes for a chromosomal fusion are together responsible for the sex‐specific and intraspecific variability in chromosome numbers. However, in contrast to the Western Palearctic Leptidea species, the single chromosomal fusion and static distribution of cytogenetic markers (18S rDNA and H3 histone genes) suggest that the karyotype of L. amurensis is stable. The data obtained for four Leptidea species suggest that the multiple sex chromosome system, although different among species, is a common feature of the genus Leptidea. Furthermore, inter‐ and intraspecific variations in chromosome numbers and the complex meiotic pairing of these multiple sex chromosomes indicate the role of chromosomal fissions, fusions, and translocations in the karyotype evolution of Leptidea butterflies.     

Cranial osteology of Picini (Aves: Piciformes: Picidae)

The Picini is composed of 26 species of woodpeckers from the old world that are grouped into seven genera. Given the absence of detailed studies on the cranial osteology of the Picini, the purpose of this study is to describe the cranial osteology of 14 species of Picini from six genera and to compare these species with each other, with other species of woodpeckers and with other bird groups. The results of the analysis of the bone structures of the skull of the Picini indicate that there are seven outstanding characteristic of bones involved in the functional mechanistics of the jaw apparatus. In the ossa cranii, these include the frontal overhang, the postorbital process, the extension of the parietal versus the frontal region and the temporal fossa. In the ossa faciei, these include the rostral expansion of the pterygoid, the ventral palatine fossa and the orbital process of the quadrate bone. For all of the structures associated with the cranial osteology of the investigated species, there is a clear distinction between the species of the genus Picus and the other species studied. Blythipicus rubiginosus, Chrysocolaptes lucidus, Reinwardtipicus validus, Gecinulus viridis and the species of the genus Dinopium exhibit additional particularities.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. II. PRUNOIDEAE: MADDENIA,PYGEUM; OSMARONIA

A survey of species of the prunoid genera, Maddenia and Pygeum, and of the genus Osmaronia has been made. The ovules of all are pendent, campylotropous, and epitropic. In the prunoids, the ovular supply is intimately connected with a central vascular plexus in the base of the carpel; that plexus is absent from Osmaronia. The prunoid carpels are marked by an extensive degree of fusion among the ovular and wing bundles, by fusion of the sutural margins, by fusion of the 2 integuments of the ovule to a single massive one, and by the presence of 3 or 5 well-developed bundles in the base. The carpel of Osmaronia also has a strongly fused bipartite ovular supply, separate bundles of which, however, become very much attenuated before reaching the funiculus; it has independent ovular and wing bundles, completely separate carpellary margins, 2 clearly separate integuments in the ovule, and 6 distinctive bundles in the carpel base. At the funiculus, the wing bundle of Osmaronia is connected with the adjoining weak ovular bundle by a well-developed vascular branch. Various particularities in the morphology of Osmaronia lend support to its segregation into a unique tribe, the Osmaronieae of Rydberg.     

Morphological provision for the specialization of hares to coprophagy: The architectonics of the mucous surface of the intestine

The macrostructure of the surface of the mucous membrane of the gastrointestinal tract were studied in detail in two hare species (Lepus europaeus and L. timidus) using scanning electron and digital microscopes. The morphology of the gastrointestinal tract of hares, which is similar in the two species studied, was described in detail. The macrostructure of the inner surface of the ileocecal junction was investigated. The particularities of the architectonics of the mucous membrane of the intestine that are specific for hares were revealed. In the jejunum of both hare species, the mucous membrane is represented by villi with merged bases, which form circular plates. The mucosa of the colon forms large conical villi, the surface of which is scattered with secreting cells. The possible functional significance of the revealed morphological particularities is discussed.     

Candoninae trapézoïdales (Crustacea, Ostracoda) du Bassin de Turiec (Slovaquie) du Miocène supérieur : systématique, écologie et évolution

The trapezoidal Candoninae from the Turiec Basin in Slovakia referred to the Candona sitari- and to C. aculeata-groups have characters that contrast with the valves of the Recent central European Candonines. The particularities concern the degree of calcification, the zone of concrescence, the overlap, and the presence of protuberances, the dorsum and the tubercles. Within the sitari-group, these characters evolve simultaneously with rapid evolution of the valve outline from subtrapezoidal to trapezoidal in shape. The species of this group acquire valve contours similar to those of the trapezoidal Candoninae of the Lake Pannon and the recent fauna of the long-lived lakes. The trapezoidal Candoninae of the Turiec Basin are associated with candonines that have triangular and rectangular carapaces with a pointed posteroventral margin. These three morphotypes indicate relatively stable habitats with weak environmental fluctuations. The trapezoidal species are rare in the littoral facies in both the north and the marginal areas of the Turiec Basin, but very abundant in the centre and south of the Basin. They probably lived in a profundal environment and their evolution probably occurred in relation to both sexual reproduction and a benthonic mode of life. The two groups comprise 18 species, of which 15 are described as new.     

C-banding in the polytene chromosomes of species of the plumosus group (Diptera,Chironomidae) and their experimental hybrids

The localization and amount of heterochromatin in the plumosus group were studied, including the species Chironomus plumosus L., C. vancouveri and C. balatonicus. The appearance of C bands of Chironomus plumosus in several European populations is traced. The role of the C heterochromatin in the differentiation of this species is discussed. From the evolutionary point of view the Swiss populations, in which large centromere heterochromatin blocks have been discovered, are more varied as to the amount of heterochromatin. The importance of duplications for this process is pointed out. The chromosomes of the individuals from C. vancouveri and C. balatonicus have centromeric, telomeric and interstitial heterochromatin. The centromeric heterochromatin is represented by thin C-bands. The particularities in the appearance of C heterochromatin in C. vancouveri and C. balatonicus reflect the structural peculiarities of their chromosomes. The change in the euchromatin regions in these forms is discussed in the light of transformation of euchromatin to heterochromatin in the process of evolution.The appearance of heterochromatin in hybrids (between populations and between species) created experimentally is traced. A change has been discovered in the appearance of heterochromatin in the hybrids compared to the initial parent forms. This difference is expressed more strongly in inter-species hybrids than in interpopulation hybrids of C. plumosus.     

Phytogeographical and phenological comparison of the Meuse and the Saône valley meadows (France)

The meadows of the floodplains of the Saône and the Meuse contain similar ecosystems subject to regular winter and spring flooding. The floristic and faunistic biodiversity decreases with the intensification of agricultural practices. The plant communities show the same zonation along a topographic gradient and have similar floristic progression. Thus, the climatic, biogeographic, human and soil factors have determined the floristic particularities of each valley. The floristic affinities of the two floodplains permitted the comparison of the phenological development of fourteen plant species. Many gaps in the development of species have been observed. These could be explained by the climatic differences betwen the two valleys (sub-Mediterranean influences in the Saône and sub-Atlantic in the Meuse), the existence of different types of soils in each valley (sand part more important in the Saône) and the occurrence of specific ecotypes in each valley.     

Exotic plant species of the St Lawrence River wetlands: a spatial and historical analysis

Aim To evaluate the importance (number of species, plant cover) of the exotic flora in seven well‐defined sectors of one of the most important transportation waterways in North America. To determine the impact of exotic species on wetland plant diversity and reconstruct the spread of some invasive species. Location St Lawrence River, southern Québec. Methods The exotic flora (vascular plants) of wetlands bordering the St Lawrence River was studied using 713 sampling stations (25 m²) along a 560‐km long corridor. Results Exotic species represent 13.7% of the vascular flora of the St Lawrence wetlands. The relative plant cover occupied by exotic species is high in some of the fluvial sectors (42–44%), but low (6–10%) in the estuarine sectors. Wetlands (marshes) surrounding islands were particularly susceptible to invasion by exotic plants. Historical, abiotic and landscape factors may explain the differences observed between sites. Purple loosestrife (Lythrum salicaria L.) is the most common exotic species of the St Lawrence wetlands, but other species, namely flowering‐rush (Butomus umbellatus L.) and reed canary grass (Phalaris arundinacea L.) are much more invasive. There is no linear relationship between the exotic species cover and the diversity of wetland plants; low diversity sites can be dominated by either exotic or native plant species. In the other sites, exotic species generally have little impact on plant communities and can contribute to increase diversity. Common reed (Phragmites australis (Cav.) Trin. ex Steudel) and reed canary grass, both considered as exotic species in this study, clearly have a stronger impact on plant diversity than flowering‐rush and purple loosestrife. Main conclusions This study shows that the global impact of an invader cannot be adequately evaluated with only a few highly invaded sites. While nationwide strategies have been developed to control exotic species, large surveys are essential to adapt them to regional particularities.     

Universalising the particular? God and Indigenous spirit beings in East Kimberley

Some Aboriginal discourses in East Kimberley appear to indicate that Indigenous particularities are being universalised by evangelical Christianity. The aim of evangelical Christianity is to bring all peoples under the domain of one God. But counter statements by people of all ages reveal that the Christian universalising project in East Kimberley is an unfinished (and possibly unfinishable) project. Although Indigenous particularities contribute to generational conflict they are not disappearing, while Aboriginal people remain on or near the lands in which their stories are embedded. Locative traditions emphasise genealogical continuities between the living and the dead. Evangelical missionaries, however, direct spirits of the living to heaven and condemn spirits of the dead to follow Satan. One Aboriginal woman has reached a kind of resolution between God and Indigenous spirits: mamu and juwarri (spirits of the dead) are not evil spirits but sinners who will be redeemed in the Last Days. 1     

Species specificity in settling-plant selection by foundress ant queens in <Emphasis Type="Italic">Macaranga</Emphasis>–<Emphasis Type="Italic">Crematogaster</Emphasis> myrmecophytism in a Bornean dipterocarp forest

Previous studies have demonstrated that the obligate myrmecophytism between Macaranga ant-plants and Crematogaster plant-ants is highly species specific, although multiple Macaranga species can coexist in a microhabitat. However, the species specificity has been described based on the study of trees with established plant-ant colonies. We studied how the process of settling into the partner Macaranga seedlings by single foundress Crematogaster queens contributes to species specificity. By sampling seedlings of three sympatric Macaranga myrmecophytes species in the field, we tested two hypotheses. The first is that foundresses correctly select their specific partner plant species when they settle into seedlings. The second hypothesis is that the seasons in which seedlings available for settling by foundresses appear are segregated among the Macaranga species, and the seasons in which foundress queens settle are synchronized to the appearance of seedlings of specific partner species; thus species specificity is consequently generated. Our results support the former hypothesis but not the latter: we always observed foundresses settling species-specific host plants, and seedlings suitable for settling were always available in each Macaranga species. Electronic Publication     

Competitive abilities and related strategies in four aquatic plant species from an intermediately disturbed habitat

1. High species richness in disturbed habitats is commonly attributed to the coexistence of species with diverse competitive abilities and, more generally, to the coexistence of different plant strategies sensu Grime (1977, 1979). The present study tests this assumption for the case of intermediately disturbed, species-rich macrophyte habitats. 2. Four species, Sparganium emersum, Hippuris vulgaris, Groenlandia densa and Luronium natans that coexist solely in one flood-disturbed, cut-off channel of the Upper Rhone River (France) were selected for this study. Apart from this common, disturbed habitat, they presented different distribution patterns within the floodplain. The present study aimed to establish both a hierarchical ranking of their competitive abilities and their respective strategies according to the C-S-R-model. 3. The study was carried out during one growth season in a de Wit experimental design with supplementary monitoring of growth characteristics. Whereas a clear ranking of species competitiveness could not be established, the experiment revealed differences in their traits and strategies. 4. S. emersum possesses the traits of a competitor, whereas the other species present intermediate secondary strategies, with a C-R-strategy in G. densa, a C-S-strategy in H. vulgaris, and a C-S-R or S-R-strategy in L. natans. These strategies are well matched to the distribution of the species within the floodplain, since the distribution of S. emersum reaches far into weakly disturbed and undisturbed, and supposedly competition intensive sites, whereas Luronium occupies a habitat that is both disturbed and relatively nutrient-poor. Only the presence of Hippuris in disturbed habitats seems not to correspond to the established strategy, but this might be explained by its need for only moderately intensive competition and by particularities of its regeneration strategy. The revealed differences in strategy may also make it possible to interpret the patchy pattern in vegetation cover within disturbed habitats.     

Phylogenetic analysis of <Emphasis Type="Italic">Kengyilia</Emphasis> species based on nuclear ribosomal DNA internal transcribed spacer sequences

Phylogenetic analysis was conducted based on sequences of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA in 17 species of Kengyilia, together with those of 18 species from Pseudoroegneria, Agropyron, Roegneria and Douglasdeweya by the maximum parsimony, maximum likelihood and neighbor-joining distance methods. The results indicate that species of Kengyilia had close affinities to species of Douglasdeweya and Agropyron. The species in Kengyilia was identified as two subgroups with regard to geographic distribution, indicating that species from the same distribution had a closer phylogenetic relationship. The genus Kengyilia was found as a ligament-group between Roegneria and Agropyron. The ITS sequence is a useful tool for studying the phylogeny of closely related species.     

Performance of camera trapping and track counts for surveying large mammals in rainforest remnants

Getting information on terrestrial large mammals is particularly difficult in tropical rainforests and in altered landscapes, since the traditionally used method (line-transect census) presents low efficiency in dense vegetation, and is difficult to standardize among heterogeneous, fragmented areas where the small size of patches restricts the length of transects. Aiming to generate information to guide the choice of field protocols for surveying terrestrial large mammals in heterogeneous rainforest remnants, we compared the performance and the correlation between the results of two alternative techniques (track counts and camera trapping), and of two types of bait, in 24 forest remnants in a fragmented Atlantic forest landscape. Techniques resulted in similar observed and estimated richness and species composition at the study landscape, including medium-sized and nocturnal species usually poorly represented in line-transect censuses. Although camera trapping resulted in a higher recording rate of the most common species (Didelphis aurita) and track counts in higher recording rates of some less common species (e.g. Dasypus novemcinctus), observed richness and recording rates of most species were correlated across the 24 sites between techniques. Conversely, the use of different baits strongly influenced results, indicating the importance of standardizing baits in comparative studies. Our results suggest that the two alternative techniques present similar performance and are suitable for studying the factors affecting the distribution of large mammals in altered rainforest landscapes. The choice of field protocols should then focus on the available resources and infrastructure, and on particularities of the study area.     

Particularities of mitochondrial structure in parasitic protists (Apicomplexa and Kinetoplastida)

Without mitochondria, eukaryotic cells would depend entirely on anaerobic glycolysis for ATP generation. This also holds true for protists, both free-living and parasitic. Parasitic protists include agents of human and animal diseases that have a huge impact on world populations. In the phylum Apicomplexa, several species of Plasmodium cause malaria, whereas Toxoplasma gondii is a cosmopolite parasite found on all continents. Flagellates of the order Kinetoplastida include the genera Leishmania and Trypanosoma causative agents of human leishmaniasis and (depending on the species) African trypanosomiasis and Chagas disease. Although clearly distinct in many aspects, the members of these two groups bear a single and usually well developed mitochondrion. The single mitochondrion of Apicomplexa has a dense matrix and many cristae with a circular profile. The organelle is even more peculiar in the order Kinetoplastida, exhibiting a condensed network of DNA at a specific position, always close to the flagellar basal body. This arrangement is known as Kinetoplast and the name of the order derived from it. Kinetoplastids also bear glycosomes, peroxisomes that concentrate enzymes of the glycolytic cycle. Mitochondrial volume and activity is maximum when glycosomal is low and vice versa. In both Apicomplexa and trypanosomatids, mitochondria show particularities that are absent in other eukaryotic organisms. These peculiar features make them an attractive target for therapeutic drugs for the diseases they cause.     

The “<Emphasis Type="Italic">Tetrahymena pyriformis</Emphasis>” complex of cryptic species

Cryptic species are common among protists and have long been known in ciliates. The ciliate genus Tetrahymena contains a large group of morphologically indistinguishable species referred to as the ‘T. pyriformis’ complex. These species include those reproductively isolated by mating type as well as asexual species characterized by the absence of the germinal micronucleus. This paper examines the molecular diversity of the species and describes the biogeography of ‘T. pyriformis’ species. Most species are globally distributed, though the best studied species, T. thermophila, is confined to North America and gives evidence of population structure in local populations. Selfers and asexual species are common and arise from sexual species, a possible exploitation of nuclear dimorphism. It is argued that the cryptic species likely have different ecological roles and that the biodiversity of Tetrahymena in particular, and ciliates in general, is underestimated. Special Issue: Protist diversity and geographic distribution. Guest editor: W. Foissner.     

Photosynthetic characteristics in <Emphasis Type="Italic">Oryza</Emphasis> species

Photosynthetic rate (P _N), SPAD value, specific leaf area (SLA), flag leaf area (FLA), and nitrogen content (LN) of genus Oryza were investigated and their correlation was analyzed to assess some of the main photosynthetic traits among different species in the genus Oryza. The results revealed wide variation in these traits. The species O. rufipogon and O. australiensis exhibited maximum photosynthetic rate. Comparison of different types of genomes (diploid: 2n=2x=24; tetraploid: 2n=4x=48) and growth habit (shade- or sun-grown) showed the species of diploid (with genome symbol EE; 2n=2x=24) genomes, with perennial and sun-grown species, had high apparent photosynthesis compared to others. The species with BB/BBCC, shade-grown and the tetraploids showed high SPAD value, and the flag leaf in sun-grown species and diploids were thicker (low SLA) compared with others. However, no significant difference could be noticed among the different types of genomes. Higher leaf area was noticed among the species of CC/CCDD genome, perennial shade-grown species and tetraploids than in others. The variety IR 36 exhibited highest leaf nitrogen concentration. Correlation analysis showed a strong relationship between P _N and leaf nitrogen concentration while no marked relationships were observed among other characteristics. It implies that the species with thick and small leaves with high nitrogen concentration and high photosynthesis evolved better than others. O. rufipogon, with the same genome as O. sativa, could be one of the wild rice resources for elite crop improvement.     

<Emphasis Type="Italic">Byssoloma rubromarginatum</Emphasis> (Pilocarpaceae: Ascomycota), a new corticolous species from <Emphasis Type="Italic">Nothofagus</Emphasis> forests in Argentina

A new corticolous species of Byssoloma, B. rubromarginatum Messuti and de la Rosa from Nothofagus dombeyi forests is described and illustrated. The new species is characterized by the morphology of the thallus and apothecia, the 3–5 (7)-septate ascospores, the presence of an anthraquinone in the exciple, and its ecology. It is the first species within the genus known to have gyrophoric acid in the apothecial margin. A key to Byssoloma species known from Nothofagus temperate forests in South America is provided.