Auriculora byssomorpha,a Tropical Lichen with a Remarkable Developmental Morphology*

The thallus, pycnidia, and the structure and ontogeny of the ascocarp in Auriculora byssomorpha are described and illustrated. The ontogeny of the apothecia is characterized by the repeated formation of new hymenia within the subhymenial layer. The development of the first hymenium is gymnocarpous but the de novo differentiation of new hymenia, each beneath the next older disintegrating one, gives rise to a peculiar type of secondary hemiangiocarpy. Portions of the decaying hymenia and adjacent subhymenial tissue frequently remain fastened to the apothecial margin and disc in the shape of ear-like appendages or as superimposed layers. In aged apothecia such decaying tissue may form a sheath around the apothecial margin and on the disc. The systematic position of the genus is briefly discussed.     

中国新疆天山山脉中部微孢衣属的研究

报道了天山山脉中部微孢衣属的3个种类,分别为被膜微孢衣(Acarospora molybdina)、疣微孢衣(Acarospora verruculosa)、戈壁微孢衣(Acarospora gobiensis)。其中被膜微孢衣为中国新记录种。该文对3种微孢衣属的地衣体和子囊盘的形态特征,以及子囊盘、子囊、子囊孢衣和侧丝等解剖特征进行了详细描述,并提供了相关彩色图片。     

A feeling for the superorganism: expression of plant form in the lichen thallus

The composite thalli produced by lichen fungi in symbiosis with algae often show structural convergences with plants. Similar overall thallus forms and branching patterns may arise in lichens with very different anatomical construction, indicating the autonomy of the morphological level of organization. Fungal and algal growth and division may be highly integrated within meristem-like morphogenetic zones in many lichens, whereas in others the symbionts may contribute in a less synchronized fashion to the construction of the thallus. Although thallus-level morphology and morphogenesis may be compared with those of plants, ontogeny of the lichen thallus differs fundamentally. Observations of lichen ontogeny illustrate the formation of the thallus by unification of autonomous, primary cellular elements in co-ordinated growth. In land plants and many algae, by contrast, the plant body is the primary structure, the cellular elements of which represent secondary subdivisions. The convergences in form are based on a common mode of nutrition in combination with cell-wall building materials that impart similar structural potential. The photosynthetic apparatus forming the basis of this mode of nutrition is not a convergent feature, however, but a homologous structure that originated in the cyanobacteria and subsequently passed laterally into diverse biological lineages by repeated endosymbioses. With consolidation of these symbioses as eukaryotic algae and plants, the organismal level of organization was repeatedly re-established with increasing degrees of complexity, and morphological convergences were expressed at these new levels. In lichens, by contrast, the symbiosis is not organismally consolidated; morphological expression instead emerges at the superorganismal level.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 89–99.     

Euopsis and Harpidium,Genera of the Lichinaceae (Lichenes) with Rostrate Asci*

Based on corresponding ascocarp ontogeny and thallus structure, the genera Euopsis and Harpidium are included in the family Lichinaceae. In the two species of Euopsis, E. granatina and E. pulvinata, the apothecia develop from ascogonia in generative tissue, while in H. rutilans they are pycnoascocarps. In thallus anatomy, the species of Euopsis resemble Pyrenopsis haematopsis and allied species, while H. rutilans corresponds in structure and development of the thallus and apothecia to Pyrenopsis haemaleella (syn. P. sphinctotricha). H. rutilans is the first member of Lichinaceae known to have only a green algal symbiont. In E. granatina, two phycobionts are always present, a species of Gloeocapsa and a chlorococcalean alga. In Euopsis and Harpidium, the ascus wall is composed of an outer, non-expansible and an inner, expansible layer; the latter surrounds the protoplast as an amyloid collar, which expands during spore release into a long, tapering rostrum. In Euopsis, the outer wall layer is strongly amyloid and the upper part separated from the expanded amyloid rostrum by a non-amyloid zone, appearing like a slit in LM studies. The ultrastructure and function of the ascus in E. granatina has been studied in TEM and is interpreted as functionally unitunicate-rostrate. Unitunicate asci with short rostrum are described for P. haemaleella and P. haematopsis.     

Redescription of Rigidohymena inquieta (Stokes, 1887) Berger, 2011 as Metahymena inquieta gen. nov., comb. nov. (Ciliophora,Hypotricha) Based on Morphology,Morphogenesis, and Molecular Phylogeny

The morphology and morphogenesis of Rigidohymena inquieta (Stokes, 1887) Berger, 2011, isolated from a lawn soil in the campus of the University of Ulsan, Korea, was studied, using live observation and protargol impregnation. The molecular phylogeny was studied based on the SSU rRNA gene sequences. The morphology of the Korean population of R. inquieta matches the previously known populations; however, the morphogenetic pattern shows differences to the species R. candens in the involvement of cirrus V/3 in the anlagen formation. A novel genus namely Metahymena gen. nov. has been erected for the present species based on the ontogenetic difference, and the new combination Metahymena inquieta gen. nov., comb. nov. is proposed. The morphology, morphogenesis, distribution, and phylogeny of M. inquieta are presented. The morphologic and morphogenetic data corroborate the phylogenetic analyses as M. inquieta clusters among the stylonychid ciliates in a clade distant from Rigidohymena candens.     

Patterns of intraspecific variation through ontogeny: a case study of the Cretaceous nautilid Eutrephoceras dekayi and modern Nautilus pompilius

The magnitude and ontogenetic patterns of intraspecific variation can provide important insights into the evolution and development of organisms. Understanding the intraspecific variation of organisms is also a key to correctly pursuing studies in major fields of palaeontology. However, intraspecific variation has been largely overlooked in ectocochleate cephalopods, particularly nautilids. Furthermore, little is known regarding the evolutionary pattern. Here, we present morphological data for the Cretaceous nautilid Eutrephoceras dekayi (Morton) and the modern nautilid Nautilus pompilius Linnaeus through ontogeny. The data are used to describe conch morphology and to elucidate the evolutionary patterns of intraspecific variation. We discovered a similar overall pattern of growth trajectories and the presence of morphological changes at hatching and maturity in both taxa. We also found that intraspecific variation is higher in earlier ontogeny than in later ontogeny in both taxa. The high variation in earlier ontogeny may imply increased flexibility in changing the timing of developmental events, which probably played an important role in nautilid evolution. We assume that the decrease in variation in later ontogeny reflects developmental constraints. Lastly, we compared the similarity/dissimilarity of ontogenetic patterns of variation between taxa. Results reveal that the similarity/dissimilarity of the ontogenetic pattern differs between E. dekayi and N. pompilius. We conclude that this shift in the ontogenetic pattern of variation may be rooted in changes in the developmental programme of nautilids through time. We propose that studying ontogenetic patterns of intraspecific variation can provide new insights into the evolution and development of organisms.     

<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.     

Lateral growth patterns in the Cladoniaceae

Lateral growth from the apex of vertical structures is widespread in cladoniiform lichens. In the family Cladoniaceae, it is accomplished through a developmental shift in the meristem, in which growth orientation changes from isotropous to anisotropous. In anisotropous development, the more or less constant relationship among the axial, radial, and circumferential planes of growth is altered during ontogeny. The result is pronounced lateral elongation of the apical meristem, a departure from the isotropous body plan of early ontogeny. Development that favors radial and circumferential growth over axial growth is an innovation that provides ontogenetic flexibility but which also entails the loss of control from a single centralized meristem to one or more meristems. A shift from the constraints of symmetry to the risks and potential of asymmetry and a subsequent diversity of heritable thallus forms reflect evolutionary processes in the Cladoniaceae. Similar morphogenetic activities, which are apparently highly conserved, are shared by species that are presumably only distantly related.     

The morphology and post-hatching development of the skull of Bolitoglossa nicefori (Caudata: Plethodontidae): developmental implications of recapitulation and repatterning

The cranial morphology of the direct-developing salamander Bolitoglossa nicefori and its post-hatching development are described and compared with that of other urodeles. Four stages of cranial development are defined on the basis of conspicuous events that occur during post-hatching ontogeny. The adult skull morphology of B. nicefori is similar to that of other plethodontids; however, some regions show interspecific variation. The post-hatching ontogeny of the skull and the stage of ossification observed in the hatchlings of B. nicefori show two important ontogenetic features: (1) a mosaic of early larval, metamorphic and post-metamorphic skull features in hatchlings, and (2) absence of characteristic larval elements in skull and hyoid apparatus. The distinctive stage of ossification in the hatchlings of B. nicefori could be caused by heterochronic changes in the ossification sequence, compared to the ontogeny of metamorphic salamanders. The possible heterochronic changes and the absence of larval traits are perhaps due to ontogenetic repatterning, yet without an obvious impact on the adult skull morphology (absence of morphological novelties). This might indicate a compartmentalized development. Further studies should be performed in order to establish the possible occurrence of recapitulatory patterns or ontogenetic repatterning in the skull morphogenesis of B. nicefori during its embryonic development.     

The Localization of Lead in the Lichen Ramalina duriaei (De Not.) Bagl.

In an attempt to ascertain whether the lichen Ramalina duriaei could be employed to biomonitor atmospheric lead pollution, specimens of this lichen were exposed to Pb (NO₃)₂ solutions and a buffered solution (tartaric acid/sodium bitartrate, pH 2.8) of sodium rhodizonate (C₆O₆Na₂) was used to locate lead in their thalli. The procedure entailed exposure of the lichen to 0, 5, 50 and 100 ppm Pb for 5 min and 1 h and the subsequent determination of the lead contents from photographs of the thalli. Distribution of lead in different parts of the thallus was assessed after exposure of the lichens to 2 ppm Pb (9 h or three d), 50 ppm (45 min) or 200 ppm (4d). Cross sections of vegetative parts of the thallus and of the apothecia revealed that lead penetrated into the cortical cells of the thallus but not into the algal cells of the phycobiont nor the ascospores or medullary cells. The observed massive penetration of lead into cortical cells supports the notion that Ramalina duriaei is sensitive to atmospheric lead pollution.     

Are ontogenetic shifts in foliar structure and resource acquisition spatially conditioned in tank‐bromeliads?

The phenotypic plasticity of plants has been explored as a function of either ontogeny (apparent plasticity) or environment (adaptive plasticity), although few studies have analyzed these factors together. In the present study, we take advantage of the dispersal of Aechmea mertensii bromeliads by Camponotus femoratus or Pachycondyla goeldii ants in shaded and sunny environments, respectively, to quantify ontogenetic changes in morphological, foliar, and functional traits, and to analyze ontogenetic and ant species effects on 14 traits. Most of the morphological (plant height, number of leaves), foliar (leaf thickness, leaf mass area, total water content, trichome density), and functional (leaf δ¹³C) traits differed as a function of ontogeny. Conversely, only leaf δ¹⁵N showed an adaptive phenotypic plasticity. On the other hand, plant width, tank width, longest leaf length, stomatal density, and leaf C concentration showed an adaptation to local environment with ontogeny. The exception was leaf N concentration, which showed no trend at all. Aechmea mertensii did not show an abrupt morphological modification such as in heteroblastic bromeliads, although it was characterized by strong, size‐related functional modifications for CO₂ acquisition. The adaptive phenotypic variation found between the two ant species indicates the spatially conditioned plasticity of A. mertensii in the context of insect‐assisted dispersal. However, ant‐mediated effects on phenotypic plasticity in A. mertensii are not obvious because ant species and light environment are confounding variables. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 299–312.     

Comparative study of chloroplast morphology and ontogeny in <Emphasis Type="Italic">Asterochloris</Emphasis> (Trebouxiophyceae,Chlorophyta)

Confocal laser scanning microscopy was utilized to compare the chloroplast morphology and ontogeny among five strains of the green alga Asterochloris. Parsimony analysis inferred from the rDNA ITS sequences confirmed their placement in three distinct lineages: Asterochloris phycobiontica, Trebouxia pyriformis and Asterochloris sp. Examination by confocal microscopy revealed the existence of interspecific differences in the chloroplast ontogeny of Asterochloris; this was based upon either specific chloroplast structures observed in a single species, or on the differential timing of particular ontogenetic sequences. The occurrence of flat parietal chloroplasts prior to cell division, considered as a basic morphological discriminative character of Asterochloris, was clearly associated with the process of aplanosporogenesis. By contrast, chloroplast transformation prior to the formation of autospores proceeded simply by the multiple fission of the chloroplast matrix in the cell lumen. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

Form of the worm:: genetics of epidermal morphogenesis in C. elegans

The development of the epidermis of the nematode worm Caenorhabditis elegans illustrates many common processes of epithelial morphogenesis. In the worm, these morphogenetic movements have been described with single-cell resolution, and the roles of individual cells have been probed in laser killing experiments. Genetic dissection is yielding insights into the molecular mechanisms of these complex morphogenetic processes.     

ASCOMA ONTOGENY: IS THIS CHARACTER SET OF ANY USE IN THE SYSTEMATICS OF LICHENIZED ASCOMYCETES?

The use of ascoma ontogeny in the systematics of lichenized asco-mycetes is reviewed briefly. Two recently studied examples are discussed to illustrate the use of ontogenetic studies to discover phylogenetic relationships. As one example, theAgyriaceaewas mainly circumscribed by the ascus type and included diverse genera.Xylographais characterized by lirelliform apothecia. However, the ascoma development shares the ontogenetic pattern observed inTrapeliaand its placement in the family was confirmed. In contrast,Anamylopsoraexhibited a substantially different apothecial development and was separated as a family of its own. As a second example, theCandelariaceaeis based on chemical characters. With the detection of pulvinic acid derivatives also in the genusLecanora, the distinction of theCandelariaceaeandLecanoraceaebecame doubtful. Therefore, the ascoma ontogeny was employed to evaluate this classification and is illustrated here in detail forCandelaria fibrosa. The substantial similarity of the ascoma development found in both families suggests that both might be better united. Finally, a general discussion of the significance of ontogenetic characters in lichen taxonomy is included.     

Role of thyroid hormone in the ontogeny and morphological diversification of <Emphasis Type="Italic">Barbus intermedius sensu</Emphasis> Banister, 1973 of Lake Tana in Ethiopia

The role of thyroid hormone in the ontogeny of the Large African barb Barbus intermedius sensu Banister, 1973 (Teleostei; Cyprinidae)—the presumed ancestral species for the species flock of the large African Barbs of Lake Tana (Ethiopia)—has been studied. It has been shown that the thyroid hormone influences the timing and rate of many morphogenetic processes and a change in its level causes heterochronies, affecting the definitive morphology of fish. Thus, it can be assumed that even a slight change in activity of the thyroid axis during ontogeny can be the cause of wide morphological variability in B. intermedius and may underlie explosive diversification of the species flock of Large African Barbs of Lake Tana.     

Ontogeny of the eodiscoid trilobite Tsunyidiscus acutus from the Lower Cambrian of South China

Abstract: The morphology and ontogeny of the eodiscid trilobite Tsunyidiscus acutus Sun is described on the basis of numerous calcified specimens collected from the Lower Cambrian Shuijingtuo Formation in Yichang and Changyang, Hubei Province, South China. An ontogenetic series is established based on the articulated material including the previously unknown protaspides and meraspides (degrees 0 and 1). The material, revealing some prominent morphological changes such as the number of pygidial axial rings, genal spines retained throughout ontogeny and pygidial pleurae from furrowed to unfurrowed, enables a discussion on the trunk segmentation schedule, indicating that somitogenesis and tagmosis occurred independently during the ontogenetic development of T. acutus.     

Ontogenetic pattern,morphological sexual and side dimorphism in the saccular otolith of a scaleless killifish Aphanius furcatus (Teleostei: Aphaniidae)

The relationships between ontogenetic and sexual factors with otolith morphology are poorly studied in killifish genus Aphanius Nardo, 1827. We studied the ontogeny, morphological sexual and side dimorphism in the saccular otolith of a scaleless killifish Aphanius furcatus inhabiting a high‐salinity environment in Southern Iran. The results highlighted growth‐dependent variability in the otolith of A. furcatus, which might be useful to define its certain developmental stages. We underlined those characters that were consistent during fish development, which could be valuable to identify the species. Considering the ontogenetic pattern of otolith in A. furcatus, it was found that the otoliths of young individuals have largely been influenced by sexes and that it was reduced during the fish development. Morphological side dimorphism in the otolith of A. furcatus tends to be increased during fish development. The outcomes of this study are essential since they have provided new information on ontogenetic changes and the sexual and side dimorphism of Aphanius otolith.     

Effect of hydrogen peroxide on morphological characteristics and resistance of wheat calluses to <Emphasis Type="Italic">T. caries</Emphasis> Tul.

We studied the effect of hydrogen peroxide on morphological characteristics and resistance of common wheat calluses ( Triticum aestivum L.) to Tilletia caries Tul. The induction of the defense response and morphogenesis in calluses depended on H₂O₂ concentration. A correlation was revealed between the elevated concentration of hydrogen peroxide in wheat calluses and high activity of oxalate oxidase in the cell wall. Administration of H₂O₂ into the callus culture medium was followed by rhizogenesis, induced the formation of dense regions, and inhibited fungal growth on calluses. Hydrogen peroxide at high concentrations was less potent in inhibiting the growth of fungi. A relationship was found between oxalate oxidase activity, H₂O₂ concentration, and morphogenetic and defense responses of calluses induced by exogenous hydrogen peroxide. These data suggest that the induction of H₂O₂ generation is one of the approaches to increase callus resistance.     

Ontogeny of the hominoid scapula: The influence of locomotion on morphology

Primate shoulder morphology has been linked with locomotor habits, oftentimes irrespective of phylogenetic heritage. Among hominoids, juvenile African apes are known to climb more frequently than adults, while orangutans and gibbons maintain an arboreal lifestyle throughout ontogeny. This study examined if these ontogenetic locomotor differences carry a morphological signal, which should be evident in the scapulae of chimpanzees and gorillas but absent in taxa that do not display ontogenetic behavioral shifts. The scapular morphology of five hominoid primates and one catarrhine outgroup was examined throughout ontogeny to evaluate if scapular traits linked with arboreal activities are modified in response to ontogenetic behavioral shifts away from climbing. Specifically, the following questions were addressed: 1) which scapular characteristics distinguish taxa with different locomotor habits; and 2) do these traits show associated changes during development in taxa known to modify their behavioral patterns? Several traits characterized suspensory taxa from nonsuspensory forms, such as cranially oriented glenohumeral joints, obliquely oriented scapular spines, relatively narrow infraspinous fossae, and inferolaterally expanded subscapularis fossae. The relative shape of the dorsal scapular fossae changed in Pan, Gorilla, and also Macaca in line with predictions based on reported ontogenetic changes in locomotor behavior. These morphological changes were mostly distinct from those seen in Pongo, Hylobates, and Homo and imply a unique developmental pattern, possibly related to ontogenetic locomotor shifts. Accordingly, features that sorted taxa by locomotor habits and changed in concert with ontogenetic behavioral patterns should be particularly useful for reconstructing the locomotor habits of fossil forms. Am J Phys Anthropol 152:239–260, 2013. © 2013 Wiley Periodicals, Inc.