MOLECULAR PHYLOGENY AND THE GEOGRAPHIC ORIGIN OF HALIOTIDAE TRACED BY HAEMOCYANIN SEQUENCES

Phylogenetic relationships of 12 species of the vetigastropodfamily Haliotidae were analysed on the basis of partial haemocyanincoding genes. Both protein-coding and genomic sequence data,of which the latter includes one ancient intron, were analysed.We were able to distinguish two genetically different monophyleticgroups with high bootstrap support: (i) the abalones from Europe,South Africa, Australia, Taiwan and Japan group together andare separated from (ii) five California and two Japanese abalones.The usefulness of haemocyanin as a phylogenetic character andthe origin of the Haliotidae are discussed. (Received 4 March 2005; accepted 4 July 2005)     

Comparative ultrastructural studies of the epidermis, sperm and nerve fibres of Cleistogamia longicirrus and Seritia stichopi (RhabdocoeIa, UmagiIIidae)

The epidermis of Cleistogamia longicirrus consists of columnar, interdigitated cells with apical mitochondria, short microvilli and cilia which have a single horizontal rootlet anchored in the adjacent cytoplasm by transverse bars and a thin side branch. Cells are held together by desmosomes and intermediary junctions. Epidermal cilia have a terminal, electron dense rod between the central microtubules and doublet 1 and a terminal plate; doublets 1 and 6–9 lose one of their microtubules and gradually all doublets lose one microtubule and peripheral doublets disappear. Spermatozoa have a single closed peripheral row of microtubules, numerous electron dense granules and mitochondria and axonemes are of the 9 +"1" type and free for most of their length. Nerve fibres have microtubules and some nerve fibres are surrounded by lamellae and have invaginations of the fibre wall. The epidermis of Seritia stichopi resembles that of Cleistogamia , but cilia have a single horizontal rootlet anchored by transverse bars in the cytoplasm, without a side branch. Spermatozoa also are similar to those of Cleistogamia . Certain ultrastructural similarities between some Umagillidae and Neodermata are apparently due to convergent evolution and do not allow the conclusion that Umagillidae and Neodermata are particularly closely related.     

Fine Structure of Pseudokeronopsis carnea (Ciliophora,Hypotrichida)1

ABSTRACT Two kinds of pigment structures, pigment vacuoles and pigmentocysts, cause the orange-red color of Pseudokeronopsis carnea (Cohn, 1866). The pigment vacuoles are undischargeable and two to five layers of them form a characteristic ectoplasmic zone. The pigmentocysts mainly surround the infraciliature and show a unique channel which is probably used for extrusion. Previous data on the fine structure of subpellicular granules and extrusomes of hypotrich ciliates are summarized. Their obviously diverse organization argues for a great value of these structures in species identification. The basic structural features of the infraciliature and the cytoplasmic organelles of P. carnea are similar to those found in other hypotrichs; however, a special kind of linear microtubular array borders the longer sides of the cirral bases and the margins of the adoral membranelles and those of the membranes in the right buccal area. To the left of the endoral membrane, these microtubular arrays result in a highly ordered structure reminiscent of oral ribs. This peculiar arrangement of microtubules in cirri and paramembranelles has also been found in the related form, Thigmokeronopsis jahodai, probably indicating a homogeneity of the fine structure of urostylid hypotrichs. In P. carnea, the basal bodies of the paroral membrane are proximally connected like a polykinetid. Its cilia are unlinked, whereas those of the endoral membrane are fused by microfibrillar material. The terms diplostichomonad and polystichomonad only refer to quantitative aspects and omit the evident, high diversity of microtubular and microfibrillar associates occurring in the membranes in the right buccal area. These terms need to be redefined on the basis of more material that is better described.     

Osmocytosis and Vacuolar Fragmentation in Guard Cell Protoplasts: Their Relevance to Osmotically-lnduced Volume Changes in Guard Cells

Guard cell protoplasts were prepared from young leaves of peaplants. Under hypertonic conditions they shrink and large numbersof endocytotic (‘osmocytotic’) vacuoles are formedby invagination of the plasma membrane. In thin section theseare indistinguishable from other small vacuoles (‘mini-vacuoles’)which are formed by fragmentation of the large central vacuole.However, the two types of vacuole can be individually recognizedby labelling the central vacuole with neutral red and by performingthe osmotic shrinkage with fluorochromes such as Lucifer Yellow-CHor Cascade Blue present in the extracellular medium. Osmocytoticvacuoles do not fuse with the plasma membrane nor with the mini-vacuolesduring a subsequent swelling phase. After several hours, osmocytosedLucifer Yellow gradually leaks out of the endocytotic vacuoleswhen protoplasts are returned to hypotonic conditions. Thisleakage is not prevented by probenecid at concentrations (20–50mmol m^–3) which do not give rise to pathological changesin protoplast ultrastructure. In order to determine the relevanceof these observations to the situation in planta, intact guardcells in epidermal strips were first allowed to accumulate neutralred in their vacuoles and then subjected to osmotic shrinkagein the presence of external Lucifer Yellow. Osmocytotic vacuoleswere not formed, although the production of mini-vacuoles wasfrequently observed. Key words: Guard cell protoplasts, fluid phase markers, Pisum sativum, probenecid, osmocytosis, shrinkage-swelling cycles     

Inheritance of body and testis size in the bushcricket Poecilimon veluchianus Ramme (Orthoptera; Tettigoniidae) examined by means of subspecies hybrids

The inheritance of three parameters of body size: body mass, hind femur length and pronotum length, and of three measurements of male fertility: testis mass, relative testis mass (as part of body mass) and sperm number per spermatophore, were examined in crosses between the bushcricket subspecies Poecilimon veluchianus veluchianus and P. v. minor . Body size parameters differed surprisingly in their apparent genetic control: the genes determining pronotum length were autosomal, hind femur length was probably partly X-chromosomal and body mass was largely determined by genes on the X-chromosome. I consider whether sexually selected traits may commonly be sex-linked. Testis mass in the hybrid males was clearly different in reciprocal hybrids and was similar to the father's subspecies in both cases. As a result of the X-chromosomal (maternal) inheritance of body mass and a testis mass similar to the paternal subspecies, the relative testis mass in the hybrid males was larger or smaller than in the pure subspecies. In the male hybrids with reduced testis mass, the mean number of sperm was strongly affected. About 50% of these males transferred only a few sperm per spermatophore.     

Lorica Construction in Eufolliculina sp. (Ciliophora,Heterotrichida)1

ABSTRACT. The structure and ultrastructure of the chitinous lorica of Eufolliculina sp. are described. The lorica is produced from precursor material secreted by the motile swarmer immediately after settling. This material is located in numerous vesicles found in the cortical region of the cells and is secreted by exocytosis. Initially, material is secreted from the ventral part of the cell to produce the attachment plate of the lorica. After this, exocytosis occurs over most of the body surface as the ampulla part of the lorica is constructed. During the later stages of lorica formation, secretion is mainly limited to the anterior of the cell as the neck is formed. The lorica is shaped mainly by the action of the cilia and by the behavior of the cell. While the neck is being formed, the anterior part of the cell is deformed by a local accumulation of cytoplasmic vacuoles. This deformation is employed in shaping the neck. No changes were detected in the organization of the cortical infraciliature during the first stages of lorica formation, but they do occur after the neck has been produced and as the swarmer develops into the sessile form.     

Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus

Walossek, D. & Müller, K. J. 1990 10 15: Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus. Lethaia , Vol. 23, pp. 409–427. Oslo. ISSN 0024–1164.
Three new arthropods in uncompressed condition have been discovered in Upper Cambrian limestone nodules (Orsten) of Västergötland, Sweden. Together with Martinssonia elongafa Müller & Walossek, 1986, they are recognized as descendants of early offshoots from the stem-lineage of Crustacea. Their morphology provides new insights into the evolutionary path and progressive development of ground plan characteristics along the stem-lineage and gives further support for the monophyletic origin of Crustacea s. str., which embraces all taxa with extant derivatives. Structures of the ventral morphology shared between these stem-lineage crustaceans and Agnostus lead to the consideration of alternatives for the currently assumed position of agnostids. ▭ Crustacea. ontogeny, phosphatization. phylogeny, stem-lineage, Sweden, 3 D-preseroation, Trilobita     

Ultrastructure of the sense receptors of adult Multicotyle purvisi (Trematoda, Aspidogastrea)

The following presumptive sense receptors of adult Multicotyle purvisi from the intestine of freshwater turtles in Malaya are described by transmission electron microscopy: disc-like receptor with many electron-dense collars and modified ciliary rootlet forming a 'disc'; non-ciliate receptor with long rootlet; non-ciliate receptor with branching rootlet and dense mass of irregularly arranged microtubules; non-ciliate receptor with rootlet fanning out from basal body, cross-striated in its upper and with electron-dense structures in its lower part; uniciliate receptor with thick layer of cytoplasm around axoneme; receptor with short cilium, at base of deep invagination of tegument; receptor with short cilium terminating in an electron-dense apical cap; and uniciliate receptor with long cilium. In addition, there may be a small non-ciliate receptor with a long ciliary rootlet at the base of the thick dorsal tegument, and uniciliate receptors differing from the uniciliate receptor with long cilium in the number of electron-dense collars and the length of the cilium and ciliary rootlet. Implications of the findings for the phylogeny of the parasitic Platyhelminthes and for evolutionary trends within that group arc discussed. The considerable degree of divergence of receptor types between the species of one family is attributed to the archaic nature of the group.