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At least 19 recordsLinked to original sources
PubMed2025

Functional Characterization of Luciferase in a Brittle Star Indicates Parallel Evolution Influenced by Genomic Availability of Haloalkane Dehalogenase.

Determining why convergent traits use distinct versus shared genetic components is crucial for understanding how evolutionary processes generate and sustain biodiversity. However, the factors dictating the genetic underpinnings of convergent traits remain incompletely understood. Here, we use heterologous protein expression, biochemical assays, and phylogenetic analyses to confirm the origin of a luciferase gene from haloalkane dehalogenases in the brittle star Amphiura filiformis. Through database searches and gene tree analyses, we also show a complex pattern of the presence and absence of haloalkane dehalogenases across organismal genomes. These results first confirm parallel evolution across a vast phylogenetic distance, because octocorals like Renilla also use luciferase derived from haloalkane dehalogenases. This parallel evolution is surprising, even though previously hypothesized, because many organisms that also use coelenterazine as the bioluminescence substrate evolved completely distinct luciferases. The inability to detect haloalkane dehalogenases in the genomes of several bioluminescent groups suggests that the distribution of this gene family influences its recruitment as a luciferase. Together, our findings highlight how biochemical function and genomic availability help determine whether distinct or shared genetic components are used during the convergent evolution of traits like bioluminescence.

Echinodermata↗
PubMed1977

Convergent and parallel evolution: a model illustrating selection, phylogeny and phenetic similarity.

A model is proposed which considers the structural relationships of body characteristics and their role in a concept wherein the phylogenetic relationship of the organisms under study is interpreted as constituting degrees of convergent or parallel evolution. The model also accounts for the relationships between selection pressures, phylogeny, and phenetic expression. The phenomena of convergent and parallel evolution are based upon the observations of similar characteristics, the geometric concept, magnitude and similarity of selection pressures, and the phylogenetic relationship of the groups in question.

Animals↗
PubMed1991

Parallel evolution in mammalian and avian brains: comparative cytoarchitectonic and cytochemical analysis.

Comparative morphology, which is based on the selection theory of evolution, analyses the impact of function upon structure and, therefore, emphasizes the adaptive events and biological advantage during the evolution of organs. A comparison based on analogies is described here as an adequate method. The hypothesis is proposed that the evolution of the brain follows the same trends in birds as in mammals. This hypothesis is proved by (1) allometric studies of brain weight and brain structure volume in relation to body weight in mammals and birds; (2) architectonic studies using image analysis on cell and fibre stains as well as on histochemical preparations and receptor autoradiography; and (3) hodological studies with injections of [3H]leucin, HRP and WGA-HRP. The results reveal a vast amount of structural and functional similarities in avian and mammalian brain organization, especially an expansion of structures that permit multimodal integration capacity in the telencephalon. Thus, a parallel evolution occurred in these two groups of vertebrates. It is argued that this may be a general phenomenon in evolution. A cladistic approach, which is based on the concept of homologies (plesio-, apomorphies), pushes aside the existence of analogies. For this reason, cladism does not seem to be a method to answer questions of evolutionary morphology adequately.

Animals↗
PubMed1974

Three flies and three islands: parallel evolution in Drosophila.

Most organisms are evolutionary conservatives; they may subdivide their niches but tend to remain within them. Yet the fossil record shows many cases of breakthrough to a new mode of life. How may such evolutionary innovation be recognized at this time level? Three species of Drosophila have accomplished an innovation in that they breed as obligate commensals on tropical land crabs. This could be dismissed as a curious aberration were it not for the fact that the three flies concerned represent three different phyletic lines of the family. Although Drosophila is abundant on the continents, these three parallel innovative evolutions have occurred on islands. The proposal is made that the genetic systems of many conservative groups of organisms carry variability that would permit them to evolve in a novel direction. The realization of this capacity, however, is possible only under special environmental conditions.

Adaptation, Biological↗
PubMed1978

Parallel evolution of pairs of dehydrogenase isoenzymes.

Lactate dehydrogenase and glycerol 3-phosphate dehydrogenase are metabolically coupled by the anaerobic dismutation of glyceraldehyde 3-phosphate and by the NAD redox state. This causes the concentrations of lactate and glycerol 3-phosphate to accumulate proportionally during anaerobic muscle contraction; these concentrations are high relative to those in aerobic tissues such as liver. We show that the isoenzymes of lactate dehydrogenase and glycerol 3-phosphate dehydrogenase from chicken breast muscle have Km values for lactate and glycerol 3-phosphate, respectively, that are 10-fold higher than the Km values measured for the lactate dehydrogenase and glycerol 3-phosphate dehydrogenase isoenzymes from chicken liver. The association of proportionally higher Km values with the potential for proportionally higher accumulation of substrates suggests that the isoenzymes of lactate dehydrogenase and glycerol 3-phosphate dehydrogenase from chicken muscle have evolved in parallel as a coupled metabolic unit distinct from the coupled isoenzymes in liver. The parallelism observed for the reduced substrates extends to the oxidized substrates, and to the coenzymes, NAD+ and NADH.

Animals↗
PubMed1991

Histochemical, connectional and cytoarchitectonic evidence for a secondary reduction of the pretectum in the European eel, Anguilla anguilla: a case of parallel evolution.

There are at least three different patterns of pretectal organization in teleost fishes: a simple pattern observed in cyprinids, an elaborate pattern present in percomorphs, and an intermediately complex pattern seen in many other teleost groups. The taxonomic distribution of the pretectal patterns indicates that the simple and the elaborate patterns are both evolutionarily derived (apomorphic) from the primitive (plesiomorphic) intermediately complex one. In anguillids, the pretectal pattern observed cytoarchitectonically has an anatomical configuration similar to that of the simple pattern in cyprinids. The distribution of acetylcholinesterase positivity in the pretectum (namely acetylcholinesterase positivity in the parvo- and magnocellular superficial and posterior pretectal nuclei, and acetylcholinesterase negativity in the pretectal cell plate and the ovoid preglomerular cell aggregate), as well as the retinal projections (namely retinal terminals in the parvocellular superficial and central pretectal nuclei, and absence of such terminals in the magnocellular superficial and posterior pretectal nuclei and the pretectal cell plate), strongly supports the interpretation suggested by the cytoarchitectonic analysis. As anguillids (elopomorpha) and cyprinids (ostariophysi) are related only distantly, this secondary simplification in the pretectum likely occurred independently, i.e. this simplification represents a case of parallel reduction.

Acetylcholinesterase↗
PubMed1990

Parallel evolution of antibody variable regions by somatic processes: consecutive shared somatic alterations in VH genes expressed by independently generated hybridomas apparently acquired by point mutation and selection rather than by gene conversion.

We identified, in independently generated hybridoma antibodies, blocks of shared somatic alterations comprising four consecutive amino acid replacements in the CDR2s of their heavy chain variable regions. We found that the nucleotide sequences encoding the shared replacements differed slightly. In addition, we performed genomic cloning and sequencing analyses that indicate that no genomic sequence could encode the block of shared replacements in any one of the antibodies and thus directly serve as a donor by a recombinational process. Finally, in a survey of other somatically mutated versions of the same heavy chain variable gene, we found several examples containing one, two, or three of the shared CDR2 mutations in various combinations. We conclude that the shared somatic alterations were acquired by several independent events. This result, and the fact that the antibodies containing the four shared mutations were elicited in response to the same antigen and are encoded by the same VH and VK gene segments, suggests that an intense selection pressure has fixed the shared replacements by favoring the clonal expansion of B cells producing antibodies that contain them. The basis of this selection pressure is addressed elsewhere (Parhami-Seren, B., L. J. Wysocki, M. N. Margolies, and J. Sharon, manuscript submitted for publication).

Amino Acid Sequence↗
PubMed1976

[New data on non-parallel evolution of karyotype and morphology in Phyllotinae (Rodents, Cricetidae)].

The non-concordance of the morphological and chromosomal evolution in the Phyllotinae is discussed in the light of the latest karyological data concerning the genus Zygodontomys: individual specimens of this genus from French Guiana present a new chromosomal formula with a high number 2 N; their karyotypical and morphological peculiarities are sufficient to warrant creating a new species Z. reigi. The great variability of the karyotypes appearing in this genus permits one to think that the various groups could represent successive aspects of the same chromosomal evolution, an increase of the number 2 N preceding an eventual decrease.

Animals↗
PubMed1991

General procedure to construct highly specific kDNA probes for clones of Trypanosoma cruzi for sensitive detection by polymerase chain reaction.

Our strategy of probes designing for major clones of Trypanosoma cruzi was performed taking into account the: (i) clear identification of the major clones under multilocus study; (ii) hypothesis of a parallel evolution between the extranuclear and nuclear markers; (iii) structure of kDNA which allowed to amplify high variable regions of the minicircle (HVRm) by PCR. The large production of HVRm was very useful to test their ability to be used as probes for detection of DNA from a diversified genetic panel of T. cruzi. Our success in designing such probes has important implications on: the enhancement of 2 evolutive hypothesis about the clonal structure of T. cruzi and the parallel evolution of their extranuclear and nuclear genetics markers; direct diagnosis in patients and vectors. Studies on bio-clinical significance of major clones are discussed. This procedure could be used as a general strategy to generate DNA probes for Kinetoplastida.

Animals↗
PubMed1990

Parallel karyotypic evolution and tumor progression in uterine leiomyoma.

Cytogenetic evidence of clonal evolution was detected in five uterine leiomyomas. In two tumors, two clones were found, the third tumor had four, the fourth had nine, and the fifth had 12 clones. The first tumor had trisomy 12 as the primary anomaly and a sideline that also contained a del(7)(q21q31). Both clones of the second tumor had three structural changes in common but differed by the presence in the more advanced clone of an inv(7)(q31q34). Two cytogenetically unrelated pairs of clones were seen in the third tumor. One clone had a stemline of 46 and an r(1); a sideline had developed through duplication of this clone. The other pair had a del(7)(q21q31) in common. The last two tumors both had t(12;14)(q14-15;q23-24) as the primary abnormality. They also had a high frequency of telomeric associations that involved certain chromosome arms only. One of the secondary changes in the fourth tumor was a del(7)(q21q31); the principal secondary change in the fifth case was a ring chromosome 1 of variable size in the different clones. The analysis of these five uterine leiomyomas and the collation of the results with previously obtained data lead us to conclude that del(7)(q21q31) is secondary to t(12;14) and + 12 in this tumor type, and that ring formation involving chromosome 1 material, often with duplication of segments, is a common phenomenon during clonal evolution. The fact that the tumors were classified as cellular and had an increased mitotic rate indicates a parallel development between histologically detectable tumor progression and cytogenetically recognizable clonal evolution in uterine leiomyomas.

Chromosome Aberrations↗
PubMedDate not supplied

Parallel gradualistic evolution of Ordovician trilobites.

There are very few high-resolution studies of the fossil record from which to assess the relative frequency of gradualistic and punctuated evolution. Here I report some of the first detailed evidence of phyletic gradualism in benthic macroinvertebrates, based on a study of approximately 15,000 trilobites from central Wales. Over a period of about three million years, as many as eight lineages underwent a net increase in the number of pygidial ribs, a species-diagnostic character. The end members of most lineages have previously been assigned to different species and, in one case, to different genera. In view of intermediate morphologies and temporary trend reversals, however, practical taxonomic subdivision of each lineage proved impossible. The apparent success of earlier Linnean nomenclature (with its implications of discrete species) could easily have been misinterpreted as evidence of punctuation and stasis, and it is probable that detection of many other gradualistic patterns has been hindered by ready application of binominal taxonomy to fossils.

Animals↗
PubMed1989

Effects of inactivity and exercise on bone.

Bone mass and muscular mass show a parallel evolution during growth, and parallel involution with age. However, the bone loss related to the withdrawal of oestrogens is independent of muscular waste. The extensive study of disuse osteoporosis shows that exercise without weightbearing cannot counteract the loss of bone mass provoked by bed rest or weightlessness. Physical training, even at low frequency (30 to 60 min/day, 2 or 3 days/week), can increase bone mass or reduce bone loss associated with age. This effect is even present when exercise is practised by very old people at a seemingly low level of muscular tension on bone. It is not known whether muscular exercise could be helpful in pathological osteopenia. Experiments in animals indicate a short-lived benefit of exercise practised during a definite growth period; the long term effect of physical training in humans, after cessation of such activity, has not been studied extensively. Equal distribution of tension on all parts of the skeleton is probably not mandatory to obtain a general effect of exercise on bone mass. It is assumed that muscular exercise acts through tension exerted on bone, but the exact mechanism is unknown, as are the specifications of effective exercise in terms of site of application, intensity, frequency and duration. Moreover, little is known about the expected synergy between exercise and occupational activity.

Aging↗
PubMed1988

The amphibian octavo-lateralis system and its regressive and progressive evolution.

The phylogenetic and ontogenetic changes in the octavolateralis system of sarcopterygian fish and tetrapods, presumed to be important for the formation of an amphibian auditory system, are reviewed. The lateral line system shows rudimentation of lines and loss of ampullary electroreceptors in many amphibians; in some amphibians it never develops. The metamorphic changes of the lateral-line system show different patterns in the different amphibian lineages with metamorphic retention in most urodeles and metamorphic loss in most anurans. The multitude of both ontogenetic and phylogenetic changes of the lateral line system among amphibians do exclude any prediction as to how this system might have changed in ancestral amniotes. The most important auditory epithelium of the tetrapod inner ear, the basilar papilla, seems to be primitively present in all tetrapods and Latimeria. In two amphibian lineages there is a trend towards rudimentation and loss of the basilar papilla. Only in the third order, the anurans, a tympanic ear develops and the inner ear shows a progressive evolution of the auditory epithelia. Together with the known differences in the periotic labyrinth of amphibians and amniotes, this scenario suggests a parallel evolution of the amniotic and anuran auditory periphery. All mechanoreceptive hair cells of the lateral line system and the inner ear appear to receive a common and bilateral efferent innervation. Among amphibians this pattern is represented only in some urodeles, whereas anurans show a derived pattern with loss of a bilateral component and presumably also of a common neuromast/inner ear component. Changes in the rhombencephalic nuclei which receive octavo-lateralis afferent fibers show a trend towards development of auditory nuclei only in the anuran lineage. The phylogenetic appearance of an auditory nucleus in this lineage coincides with the complete absence of formation of ampullary electroreceptors. In contrast, the earlier claim of a correlation between a metamorphic loss of the lateral line system and the formation of an auditory nucleus is not supported by more recent data: an auditory nucleus develops in anurans already prior to metamorphosis and is present in all anurans even when they retain the neuromast system. In anurans with a metamorphic loss of the neuromasts, the second order neurons degenerate as well. This independence of the auditory and the second order lateral line nuclei is further substantiated by their separate projection to other brain areas, like the torus semicircularis of the midbrain, and their functional properties.(ABSTRACT TRUNCATED AT 400 WORDS)

Amphibians↗