New methods for species and sex determination in three sympatric Mustelids, Mustela itatsi, Mustela sibirica and Martes melampus

We developed novel species and sex determination methods for three Japanese mustelid species. We used DDX3Y to determine sex and generated a primer set to amplify both DDX3X and DDX3Y DNA in Mustela itatsi, M. sibirica and Martes melampus. To determine species and sex simultaneously, we generated fluorescence-labelled primers that give different fragment lengths at D-loop, DDX3X and DDX3Y of these three species using a DNA sequencer.     

Evolutionary transfers of mitochondrial genes to the nucleus in the Populus lineage and coexpression of nuclear and mitochondrial Sdh4 genes

The transfer of mitochondrial genes to the nucleus is an ongoing evolutionary process in flowering plants. Evolutionarily recent gene transfers provide insights into the evolutionary dynamics of the process and the way in which transferred genes become functional in the nucleus. Genes that are present in the mitochondrion of some angiosperms but have been transferred to the nucleus in the Populus lineage were identified by searches of Populus sequence databases. Sequence analyses and expression experiments were used to characterize the transferred genes. Two succinate dehydrogenase genes and six mitochondrial ribosomal protein genes have been transferred to the nucleus in the Populus lineage and have become expressed. Three transferred genes have gained an N-terminal mitochondrial targeting presequence from other pre-existing genes and two of the transferred genes do not contain an N-terminal targeting presequence. Intact copies of the succinate dehydrogenase gene Sdh4 are present in both the mitochondrion and the nucleus. Both copies of Sdh4 are expressed in multiple organs of two Populus species and RNA editing occurs in the mitochondrial copy. These results provide a genome-wide perspective on mitochondrial genes that were transferred to the nucleus and became expressed, functional genes during the evolutionary history of Populus.     

Evolutionary trends in the Central American species of Piper (Piperaceae)

The gross morphology of the Central American species ofPiper is surveyed in respect to habit and habitat, protection of the shoot-tip, form and condensation of the inflorescence and floral parts, and anther-dehiscence. The cap-like structure covering the shoot-tip in many species is interpreted as a modified prophyll. A ligulate development and the inclusion of the inflorescence within the sheathing leaf-base in a few species are discussed. Diminution and compaction of the floral parts are interpreted as an evolutionary response to the activities of small pollen-collecting bees. Compaction of the floral parts is correlated with a truncation of the pistil apex and, in a few species, with a change in the mode of anther dehiscence. Apical and upward dehiscence of the anthers are interpreted as similar adaptations caused by a restriction of the pollinator’s activity to the surface of the spike. A relationship between ants and certain hollow-stemmed species is mentioned. The multiple origins and independent lines of evolutionary development discussed here suggest a complex phyletic history of the genus.     

A comparative description of mitochondrial DNA differentiation in selected avian and other vertebrate genera

Levels of mitochondrial DNA (mtDNA) sequence divergence between species within each of several avian (Anas, Aythya, Dendroica, Melospiza, and Zonotrichia) and nonavian (Lepomis and Hyla) vertebrate genera were compared. An analysis of digestion profiles generated by 13-18 restriction endonucleases indicates little overlap in magnitude of mtDNA divergence for the avian versus nonavian taxa examined. In 55 interspecific comparisons among the avian congeners, the fraction of identical fragment lengths (F) ranged from 0.26 to 0.96 (F = 0.46), and, given certain assumptions, these translate into estimates of nucleotide sequence divergence (p) ranging from 0.007 to 0.088; in 46 comparisons among the fish and amphibian congeners, F values ranged from 0.00 to 0.36 (F = 0.09), yielding estimates of P greater than 0.070. The small mtDNA distances among avian congeners are associated with protein-electrophoretic distances (D values) less than approximately 0.2, while the mtDNA distances among assayed fish and amphibian congeners are associated with D values usually greater than 0.4. Since the conservative pattern of protein differentiation previously reported for many avian versus nonavian taxa now appears to be paralleled by a conservative pattern of mtDNA divergence, it seems increasingly likely that many avian species have shared more recent common ancestors than have their nonavian taxonomic counterparts. However, estimates of avian divergence times derived from mtDNA- and protein-calibrated clocks cannot readily be reconciled with some published dates based on limited fossil remains. If the earlier paleontological interpretations are valid, then protein and mtDNA evolution must be somewhat decelerated in birds. The empirical and conceptual issues raised by these findings are highly analogous to those in the long-standing debate about rates of molecular evolution and times of separation of ancestral hominids from African apes.      

TheAdh genomic region ofDrosophila ambigua: Evolutionary trends in different species

Summary The study of individual genes is essential to a comprehensive understanding of genome evolution. The wealth of information on alcohol dehydrogenase (Adh) inDrosophila makes this gene particularly suitable for such analysis. We have characterized more than 4 kb of the genomicAdh region inDrosophila ambigua and compared this region toDrosophila mauritiana andDrosophila pseudoobscura. The presence of two genes,Adh and 3ORF (open reading frame), has been confirmed and some of their essential features have been inferred from primary structural analysis. Inter- and intraspecific comparisons have led us to support that both genes may have diverged from an ancient precursor. They appear to be evolving independently, and show a species-specific pattern. TheAdh in theobscura group species lacks amino acids three and four when compared to the species of themelanogaster group and has accumulated most of its amino acid replacements in the third exon. Neither characteristic is observed when any other group species are compared, which suggests that these may be particular features of the evolution of theobscura group. The 3ORF is highly conserved among the three species analyzed, although variability in the length of the third exon and the nucleotide substitution rate, which is much higher than inAdh, are worth noting. According to our data, both mutation/fixation rates and the distribution of mutations vary over time, which makes it difficult to predict the evolutionary dynamics of specific genome regions.     

Cell differentiation lineage in the prostate

Prostatic epithelium consists mainly of luminal and basal cells, which are presumed to differentiate from common progenitor/stem cells. We hypothesize that progenitor/stem cells are highly concentrated in the embryonic urogenital sinus epithelium from which prostatic epithelial buds develop. We further hypothesize that these epithelial progenitor/stem cells are also present within the basal compartment of adult prostatic epithelium and that the spectrum of differentiation markers of embryonic and adult progenitor/stem cells will be similar. The present study demonstrates that the majority of cells in embryonic urogenital sinus epithelium and developing prostatic epithelium (rat, mouse, and human) co-expressed luminal cytokeratins 8 and 18 (CK8, CK18), the basal cell cytokeratins (CK14, CK5), p63, and the so-called transitional or intermediate cell markers, cytokeratin 19 (CK19) and glutathione-S-transferase-pi (GSTpi). The majority of luminal cells in adult rodent and human prostates only expressed luminal markers (CK8, CK18), while the basal epithelial cell compartment contained several distinct subpopulations. In the adult prostate, the predominant basal epithelial subpopulation expressed the classical basal cell markers (CK5, CK14, p63) as well as CK19 and GSTpi. However, a small fraction of adult prostatic basal epithelial cells co-expressed the full spectrum of basal and luminal epithelial cell markers (CK5, CK14, CK8, CK18, CK19, p63, GSTpi). This adult prostatic basal epithelial cell subpopulation, thus, exhibited a cell differentiation marker profile similar to that expressed in embryonic urogenital sinus epithelium. These rare adult prostatic basal epithelial cells are proposed to be the progenitor/stem cell population. Thus, we propose that at all stages (embryonic to adult) prostatic epithelial progenitor/stem cells maintain a differentiation marker profile similar to that of the original embryonic progenitor of the prostate, namely urogenital sinus epithelium. Adult progenitor/stem cells co-express both luminal cell, basal cell, and intermediate cell markers. These progenitor/stem cells differentiate into mature luminal cells by maintaining CK8 and CK18, and losing all other makers. Progenitor/stem cells also give rise to mature basal cells by maintaining CK5, CK14, p63, CK19, and GSTpi and losing K8 and K18. Thus, adult prostate basal and luminal cells are proposed to be derived from a common pleuripotent progenitor/stem cell in the basal compartment that maintains its embryonic profile of differentiation markers from embryonic to adult stages.     

Evolutionary trends in the genus Bordetella

The genus Bordetella comprises seven species with pathogenic potential for different host organisms. This article attempts to review our current knowledge about the systematics and evolution of this important group of pathogens, their relationship to environmental microorganisms and about molecular mechanisms of host adaptation.     

Evolutionary trends in the androecium of theOrchidaceae

The evolution of the androecium in theOrchidaceae shows three major trends. There is a progressive trend in the degree of fusion of the filament(s) and staminode(s) to the gynoecium. Secondly, there is a reduction in the number of fertile anthers. Finally, there is a progressive change in the position of the base of the anther relative to the apex of the stigma; in the more primitive orchids the apex of the stigma is always higher than the base of the anther (this position is reversed in the higher orchids). All three trends reflect variation in the evolution of pollen dispersal and pollen reception mechanisms in theOrchidaceae. Trends in the evolution of the orchid anther(s) tend to parallel trends in the evolution of their pollinaria.     

Evolutionary relationships among the male and female mitochondrial DNA lineages in the Mytilus edulis species complex

A novel form of mitochondrial DNA (mtDNA) inheritance has previously been documented for the blue mussel (Mytilus edulis). Female mussels inherit their mtDNA solely from their mother while males inherit mtDNA from both their mother and their father. In males, the paternal mtDNA is preferentially amplified so that the male gonad is highly enriched for the paternal mtDNA that is then transmitted from fathers to sons. We demonstrate that this mode of mtDNA inheritance also operates in the closely related species M. galloprovincialis and M. trossulus. The evolutionary relationship between the male and female mtDNA lineages is estimated by phylogenetic analysis of 455 nucleotides from the large subunit ribosomal RNA gene. We have found that the male and female lineages are highly divergent; the divergence of these lineages began prior to the speciation of the three species of blue mussels. Further, the separation between the male and female lineages is estimated to have occurred between 5.3 and 5.7 MYA.      

The complete mitochondrial genome of sable, Martes zibellina

The complete mitogenome sequence of the Sable (NC_011579) was determined using long PCR (Polymerase Chain Reaction). The genome was 16,523?bp in length and contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and 1 control region. The gene composition and order of which was similar to most other mammals. The overall base composition of the heavy strand in descending order is A (32.0%), C (27. 6%), T (25.8%) and G (14.7%). The base compositions present clearly the A-C skew, which is most obviously in the control region and protein-coding genes. The extended termination-associated sequence domain, the central conserved domain, and the conserved sequence block domain are defined in the mitochondrial genome control region of Sable. This mitogenome sequence data would play an important role in phylogenetics and systematics of Martes zibellina.     

Evolutionary trends in wading birds

For the most part populations ot wading birds have expanded and contracted with the variations in the extent of their habitats during the Pleistocene. It is suggested that as a result of geographical isolation, populations of the same species have evolved to a level at which secondary hybridization has resulted on their again coming together. 'Southern' forms of some wading birds have resulted from this secondary hybridization and in some cases the increased heterogeneity has given rise to new evolutionary potential. It is suggested that this may have occurred many times during the Pleistocene and that microevolution has played a significant part in the evolution of wading birds.     

Evolutionary trends in sperm structure

In the marine invertebrates which practise external fertilization, the spermatozoon is a flagellate cell, possessing an acrosomal complex made up of acrosome and perforatorium. In the animal phyla which adapted to land after having achieved internal fertilization the spermatozoon has acquired an elongated shape and develops accessory cytoskeletal organelles in the tail. In the highest forms, the flagellum seems to have become too long for perfect motility; in such a condition, aberrant axonemal patterns can appear and aflagellate spermatozoa can also be found. At the apex of the terrestrial phyla, alternative motile apparatuses have been achieved and also the acrosomal complex varies, according to the different structures of egg envelopes.     

Evolutionary trends in Winteraceae pollen

The Winteraceae, being considered as one of the most basal angiosperm families, has been extensively studied palynologically. The present study reviews the characters dispersal unit (monad versus tetrad) and size of the lumina in the tectum in the light of recent molecular research. Monads and small-meshed reticula appear to be derived from large-meshed tetrads. The fossil record supports the apomorphic state of a small-meshed tectum. In contrast to earlier reports, genuine monads are unknown as fossils. The fossil monads recorded so far are considered to be detached from permanent tetrad configurations.     

Field immobilization of American martens (Martes americana) and short-tailed weasels (Mustela erminea).

Ketamine hydrochloride (KH) and a 5:1 combination of KH and xylazine hydrochloride (XH) were used successfully to immobilize short-tailed weasels (Mustela erminea) and American martens (Martes americana), respectively. Four adult male martens were intramuscularly injected with 30 to 82 mg/kg KH and 8.0 to 16.4 mg/kg XH. Three adult male short-tailed weasels were intramuscularly injected with 20.8 to 42.1 mg/kg KH. Mean (+/- SE) induction times for martens and short-tailed weasels were 1.8 +/- 0.2 min and 46 +/- 4.1 sec, respectively; recovery times were 100.4 +/- 19.3 min and 97.9 +/- 6.3 min, respectively. Heart rate was relatively constant among martens; however, respiration varied widely (21 to 122 breaths per minute). Marten body temperature decreased between 0 and 20 min post-recumbency. Short-tailed weasel heart rate and respiration decreased in response to sedation until slightly before arousal. Body temperature stabilized by 20 min post-recumbency. Two short-tailed weasels tremored slightly within 10 min of arousal. I conclude that KH and KH/XH are safe immobilizing agents for martens and short-tailed weasels, respectively.     

Coordinate reciprocal trends in glycolytic and mitochondrial transcript accumulations during the in vitro differentiation of human myoblasts

Changes in the mRNA levels during mammalian myogenesis were compared for seven polypeptides of mitochondrial respiration (the mitochondrial DNA-encoded cytochrome oxidase subunit III, ATP synthase subunit 6, NADH dehydrogenase subunits 1 and 2, and 16S ribosomal RNA; the nuclear encoded ATP synthase beta subunit and the adenine nucleotide translocase) and three polypeptides of glycolysis (glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase, and triose-phosphate isomerase). Progressive changes during the conversion from myoblasts to myotubes were monitored under both atmospheric oxygen (normoxic) and hypoxic environments. Northern analyses revealed coordinate, biphasic, and reciprocal expression of the respiratory and glycolytic mRNAs during myogenesis. In normoxic cells the mitochondrial respiratory enzymes were highest in myoblasts, declined 3- to 5-fold during commitment and exist from the cell cycle, and increased progressively as the myotubes matured. By contrast, the glycolytic enzyme mRNAs rose 3- to 6-fold on commitment and then progressively declined. When partially differentiated myotubes were switched to hypoxic conditions, the glycolytic enzyme mRNAs increased and the respiratory mRNAs declined. Hence, the developmental regulation of muscle bioenergetic metabolism appears to be regulated at the pretranslational level and is modulated by oxygen tension.     

Evolutionary trends in Mediterranean flora and vegetation

Summary The vegetation of the Mediterranean Basin was originally composed of evergreen forests; during the Pleistocene deciduous forests expanded, chiefly in the mountains. In historical time the forest belt was strongly reduced by human activity and substituted by anthropogenous vegetation types (macchia, garigue, weed-communities). The frequency of polyploids in the present vegetation types support this interpretation. Reciprocal relationships between the vegetational system and social system are discussed and a terminology is proposed. During ancient times and the middle ages a reciprocal control of vegetation and human activity was possible (cyclic system), stabilizing the vegetation in a steady state; the technological impact modified these conditions in a linear sense, and now the vegetation is menaced by irreversible changes.Contribution to the Symposium on Plant species and plant communities, held at Nijmegen, 11–12 November 1976, on the occasion of the 60th birthday of Professor Victor Westhoff.