Taxonomy of the African giant pouched rats (Nesomyidae: Cricetomys): molecular and craniometric evidence support an unexpected high species diversity

Our study combined a mitochondrial cytochrome b phylogeny with cranial measurements from giant pouched rats collected across sub‐Saharan Africa. The mitochondrial phylogeny resolves two West African clades and a clade with east and central Africa representatives. This last clade can be further divided into four subclades. Altogether they represent six species (Cricetomys gambianus, Cricetomys ansorgei, Cricetomys emini, and three undescribed taxa) that can be distinguished on the basis of their mitochondrial DNA sequences and craniometry. In the absence of adequate craniometric data the existence of Cricetomys kivuensis cannot be confirmed by our data. Our combined molecular and craniometric data allowed us to broadly delineate the distribution ranges of the detected species. Cricetomys gambianus occurs in the savannah and forest clearings of West Africa. Cricetomys ansorgei is distributed in the savannah of East and southern Africa. Cricetomys emini, as currently recognized across the Guineo‐Congolian forest of Africa, is shown to be diphyletic. Cricetomys sp. 1, a separate operational taxonomic unit closely resembling C. emini, occurs in the forest zone of West Africa. An undescribed sister‐species of C. ansorgei, Cricetomys sp. 2, occurs in the forest of Central Africa along the left bank of the Congo River. Cricetomys sp. 3 occurs on the right bank of the Congo River from Cameroon to the Republic of Congo, whereas the true C. emini also occurs on the right bank of the Congo River but appears to be restricted to the Democratic Republic of Congo. Cranial phenotype within the genus tends to conform to ecological zonation (either forest or savannah) rather than to phylogenetic affiliation of the species concerned, suggesting that diversifying selection across environmental gradients could be responsible for biological diversification within the genus.     

A MEDIUM FOR THE CULTIVATION OF LACTOBACILLI

SUMMARY: An improved growth medium for lactobacilli is described. It supports good growth of lactobacilli generally and also is particularly useful for a number of fastidious strains which grow only poorly in other general media. In addition, tomato juice, a highly variable material, is not required. In a slightly modified form, it can also be used as a basal medium for fermentation tests.     

Rhythmic Growth Rings of Wood and Their Relationship with the Foliage in Oak Seedlings Grown in a Favourable Environment

The anatomy of wood was studied inQuercus roburL. andQuercussuberL. seedlings exhibiting 3–8 units of extension, eachwith a tier of photosynthesizing leaves in their upper parts,generated as the result of rhythmic shoot growth under favourableconditions. At all the axis levels examined (i.e. the base ofeach of the different units of extension, four other equidistantlevels within the first unit of extension and the upper partof the taproot), the wood displayed rings when treated withWiesner reagents. This indicated cinnamaldehyde groups presentin lignins. No rings appeared when the Maüle reaction wasused for specific detection of syringyl subunits in lignins.A trend towards a periodical arrangement of xylem parenchymabands was also found when sections were treated with I₂/KI.The number of rings coincided with the number of leaf tiersabove the level of measurement, and did not vary inside thefirst unit of extension. Thus, the rings are called rhythmicgrowth rings. In sections of the first and the second unitsof extension, and in the taproot, the area and width of a givenrhythmic growth ring were highly correlated with the total areaof leaves present above the level of measurement at the presumedtime of growth ring formation. Moreover, stem diameter at thebase of the units of extension was highly correlated with theleaf area above. These results indicate that differentiationof xylem, particularly its lignification, varies rhythmicallyin oak seedlings. They imply that wood production is linkedto the photosynthesizing and/or transpiring area of the plant.Thus, during a growth cycle ofQ. roburandQ. suberseedlings,there appears to be integration of the primary metabolic activitieswith the laying down of rhythmic growth rings.Copyright 1998Annals of Botany Company Allometric relationship, juvenile wood, leaf area, lignification, oak seedling, periodic structure,Quercus roburL.,Quercus suberL., rhythmic growth ring, unit of extension.     

A PANEL PERFORMANCE PROCEDURE IMPLEMENTED IN R

Monitoring performance is essential for the efficient use of a sensory panel both during training and while carrying out product assessments. We present a concise procedure to monitor panel performance based on classical statistical methods. The program includes tests for the ability to discriminate between products, repeatability of assessments, scale use, agreement between panelists and a principal component analysis map of panelist means across attributes. The algorithm is implemented in R – a state‐of‐the‐art, freely available statistical software package. The program output is summarized in graphs and tables. This easily applicable panel performance procedure is aimed at improving sensory practice, especially in areas where the use of highly complex systems is not feasible.     

A phylogenetic reconstruction of the Ichneumonoidea (Hymenoptera) based on the D2 variable region of 28S ribosomal RNA

The D2 variable region of 28S rRNA was sequenced in a wide range of Ichneumonoidea to provide the first comprehensive phylogenetic reconstruction of this superfamily. The two constituent families (Braconidae and Ichneumonidae) were each found to contain a single well-supported clade dominated by the more plesiomorphic life history strategies (idiobiosis, ectoparasitism and attacking endoephytic hosts). In the Braconidae this clade corresponds to the morphologically-defined group called the cyclostomes. In the Ichneumonidae the clade unites for the first time the pimpliformes ( sensu Wahl) with most of the phygadeuontoid subfamilies and several small taxa including Adelognathus and Euceros . Relationships among the remaining, more biologically-derived, subfamilies were less well resolved, but included among the Braconidae a well-supported microgastroid clade and strong evidence for a sister group relationship between the Agathidinae and Sigalphinae.     

Ultrastructure and Cytochemistry of the Cell-types in the Tumorous Hematopoietic Organs and the Hemolymph of the Mutant Lethal (1) Malignant Blood Neoplasm (l(1)mbn) of Drosophila Melanogaster

The fine structure and histochemistry of the neoplastic primordial blood cell-types in the larval hematopoietic organs and the mature cell-types in the hemolymph of the blood tumor mutant lethal (1) malignant blood neoplasm (l(1) mbn ) of Drosophila melanogaster were investigated. In this mutant the cell-types of the plasmatocyte-line are neoplastic while the cell-types of the crystal-cell-line are not and are much reduced in numbers (1, 2).
In contrast to the wild-type the mutant hematopoietic organs are enlarged and contain, in addition to primordial blood-cells, large numbers of mature plasmato-, podo-, and lamellocytes.
All cell-types of the plasmatocyte-line differ in their fine structure and behavior from their wild-type counterparts. The mutant blood cells show generally a numerical increase of cell organelles and acid phosphatase positive primary and secondary lysosomes. In the phenol oxidase test they showed a vigorous melanization reaction. Plasmato- and podocytes invade into the tissues of the larva and show high phagocytic activity.     

Ultrastructure and Cytochemistry of the Cell Types in the Larval Hematopoietic Organs and Hemolymph of Drosophila Melanogaster

The ultrastructure of the primordial blood cells in the first and second hematopoietic lobes of the late second and third instar larva and prepupa of Drosophila melanogaster was compared with the ultrastructure of the blood cells found freely in the larval hemolymph. Within the hematopoietic lobes two principal cell-types were detected: (i) the prohemocytes and proplasmatocytes, and (ii) different developmental stages of crystal cells., Prohemocytes are characterized by a ribsome-rich cytoplasm, showing small amounts of mitochondria, rough ER and Golgi complexes and few primary lyosomes. Prohemocytes differentiate into proplasmatocytes. When released into the hemolymph they transform further into plasmato-, podo-, and lamellocytes. This differentiation pathway is characterized by a gradual, numerical increase of cytoplasmic organelles, the development of the lysosomal system and the aquisition of the capacity for phagocytosis and melanin formation. The differentiation of a procrystal cell into a crystal cell involves a number of intermediate stages, during which the crystalline material is produced, accumulated, and crystallized. Primary and secondary lysosomes in the primordial blood cells of the hematopoietic organs as well as the free blood cells in the hemolymph were identified cytochemically with the help of the acid phosphatase test. The capacity for melanin synthesis was studied with the phenol- and polyphenol oxidase test.     

Molecular systematics of mantelline frogs from Madagascar and the evolution of their femoral glands

Several genera of frogs from Madagascar, classified in the family Mantellidae, subfamily Mantellinae, possess structures commonly called 'femoral glands' on the ventral side of their shanks. The question arises as to the origin and phylogenetic significance of these glands. A molecular phylogeny based on 3601 nucleotide DNA sequences of three mitochondrial and two nuclear genes of 30 mantellid species provided strong support for monophyly of the included mantellines, all characterized by enlarged femoral gland clusters, as well as for those with gland clusters of coordinated central arrangement of secretion ducts. However, the phylogeny also strongly supported the hypothesis of convergent evolution of structurally similar glands in unrelated frogs ( Indirana , Petropedetes ), and several trends of convergent evolution of gland structure within mantellines. We studied the light microscopic structure of the femoral glands in a representative array of 18 mantellid species. Males of all species of the subfamily Mantellinae were characterized by clusters of distinct single glands. Each was structurally similar to an enlarged granular gland and secreted independently, probably through a single duct. By contrast, the largely semi-aquatic frogs in the genus Mantidactylus had a specialized cluster of glands, in which the secretion ducts led into a macroscopically recognizable central depression. In Boophis opisthodon , a mantellid species of the subfamily Boophinae without externally recognizable femoral glands, we observed a large number of enlarged granular glands of various sizes in the ventral skin of the shank. This observation is consistent with the hypothesis that the large and more uniform organs of mantellines are derived granular glands.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 529–539.