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PubMed1995

[Splenic lymphoma with circulating hairy lymphocytes lymphoma. Clinical cytological study of 4 patients].

PURPOSE: The splenic lymphoma with circulating villous lymphocytes (SLCVL) is an infrequent disease included within the low grade non Hodgkin's lymphoma, B-cell type. The results of the study of four patients are reported. PATIENTS AND METHODS: Clinical, cytological, immunophenotypic, ultrastructural, evolutive and therapeutic data have been revised in all the cases. RESULTS: Two males and 2 females of 76, 66, 68 and 62 years, respectively were diagnosed as having SLCVL. The initial symptoms were scarce, basically asthenia, and a big spleen without significant lymphadenopaty was the most relevant physical finding in each of them. In peripheral blood leukocyte count was normal with a slight lymphocytosis and a variable percentage of villous circulating lymphocytes. The immunophenotype of peripheral blood obtained by flow cytometry was according with a mature B-cell lymphocyte population, CD 5 and CD 25 negative. The cells were positive to acid phosphatase with a diffuse pattern of variable intensity; the reaction was inhibited by tartaric acid. All the patients had BM infiltration, studied with aspiration and biopsy. One case (M,66) had an IgM monoclonal gammopathy. The ultrastructural study, performed in 3 cases, showed thin and short villous prolongations. After splenectomy, a low degree lymphoma therapy has been employed in all the cases. The follow-up ranges between, 4 years and 4 months, all the patients being alive. CONCLUSIONS: The SLCVL is a definitive entity regarding the clinical, morphologic and immunophenotype features. A long clinical evolution and a good prognosis after splenectomy are common.

Aged↗
PubMed1991

Molecular evolution and phylogeny of the Drosophila virilis species group as inferred by two-dimensional electrophoresis.

Systematic relationship among the 12 species of the Drosophila virilis species group, and Drosophila robusta, were investigated by the use of two-dimensional electrophoresis (2-DE). A total of 389 protein characters (about 200 loci) were scored and analyzed both phylogenetically and phenetically. The resulting phylogeny was found to be largely concordant with the current views of evolution among these species based on other independent morphological, chromosomal, electrophoretic, and immunological data sets, although some notable differences were observed. The 2-DE data also appeared to be useful for constructing a molecular clock to date the absolute times of divergence among the species. It appears from this analysis that the evolution of the major clades within the species group occurred about 20 million years ago. Previous suggestions that the rate of molecular evolution was different between the virilis and montana phylads was not confirmed. The technique of 2-DE seems to be an excellent tool for reconstructing phylogenies and should be particularly valuable for examining relatively closely related species.

Animals↗
PubMed2005

The evolution of polymorphic sexual systems in daffodils (Narcissus).

Narcissus, the daffodil genus, exhibits an unusual diversity of sexual systems, with populations that are monomorphic, dimorphic or trimorphic for style length. Associated with this variation are striking differences among species in floral morphology and pollination biology. This diversity provides an opportunity to investigate the evolution of mating polymorphisms, and to determine how floral morphology promotes transitions among sexual systems. Because of the absence of heteromorphic incompatibility in Narcissus, floral morphology plays a key role in governing patterns of outcrossed mating. Phylogenetic evidence indicates that stylar monomorphism is ancestral in the genus, with multiple origins of stylar polymorphism, including independent origins of stigma-height dimorphism, distyly and tristyly. Sexual polymorphisms have evolved only in lineages with narrow floral tubes that are pollinated by Lepidoptera and/or long-tongued bees. Populations of polymorphic Narcissus species are typically dominated by the long-styled morph and display imperfect reciprocity in the positions of sexual organs. These features are consequences of the unusual association between stylar polymorphism and a self-incompatibility system that permits intramorph mating.

Biological Evolution↗
PubMed2003

Reconstructing cetacean brain evolution using computed tomography.

Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This approach will provide new insights into the little-known evolutionary history of cetacean brain evolution.

Animals↗
PubMed1998

Expression pattern of a butterfly achaete-scute homolog reveals the homology of butterfly wing scales and insect sensory bristles.

BACKGROUND: Lepidopteran wing scales are the individual units of wing color patterns and were a key innovation during Lepidopteran evolution. On the basis of developmental and morphological evidence, it has been proposed that the sensory bristles of the insect peripheral nervous system and the wing scales of Lepidoptera are homologous structures. In order to determine if the developmental pathways leading to Drosophila sensory bristle and butterfly scale formation use similar genetic circuitry, we cloned, from the butterfly Precis coenia, a homolog of the Drosophila achaete-scute (AS-C) genes--which encode transcription factors that promote neural precursor formation--and examined its expression pattern during development. RESULTS: During embryonic and larval development, the expression pattern of the AS-C homolog, ASH1, forecasted neural precursor formation. ASH1 was expressed both in embryonic proneural clusters--within which an individual cell retained ASH1 expression, enlarged, segregated, and became a neural precursor--and in larval wing discs in putative sensory mother cells. ASH1 was also expressed in pupal wings, however, in evenly spaced rows of enlarged cells that had segregated from the underlying epidermis but, rather than give rise to neural structures, each cell contributed to an individual scale. CONCLUSIONS: ASH1 appears to perform multiple functions throughout butterfly development, apparently promoting the initial events of selection and formation of both neural and scale precursor cells. The similarity in the cellular and molecular processes of scale and neural precursor formation suggests that the spatial regulation of an AS-C gene was modified during Lepidopteran evolution to promote scale cell formation.

Amino Acid Sequence↗
PubMed1981

Karyotype evolution and sex chromosome differentiation in Schistosomes (Trematoda, Schistosomatidae).

The morphology of C-banded metaphase chromosomes has been studied in two hermaphroditic and ten gonochoristic digenetic trematodes (schistosomes). Comparison of numbers and morphology of chromosomes indicates that the karyotype of primitive trematodes probably was composed of 10 (or 11) pairs of telocentric or subtelocentric chromosomes, and reduction of chromosome numbers in advanced species resulted from centromeric fusion rather than elimination of chromosomes. Observation of heteromorphic chromosomes in a hermaphroditic trematode (Spirorchis) suggested a differentiation of "pre-sex" chromosomes in species ancestral to dioecious trematodes which possess distinctly differentiated sex chromosomes. Our results indicate that differentiation of Z and W chromosomes in the gonochoristic trematodes resulted from: (a) partial constitutive heterochromatinization of the W chromosome (Schistosoma mansoni and S. haematobium complexes, African schistosomes), (b) deletion of part of the W (S. japonicum and S. mekongi, Asian schistosomes), and (c) translocation of part of one sex chromosome onto another (Schistosomatium douthitti and Heterobilharzia americana, American schistosomes) with subsequent heterochromatinization of the W in H. americana.

Animals↗
PubMed1975

The functional morphology of the cercopithecoid wrist and inferior radioulnar joints, and their bearing on some problems in the evolution of the Hominoidea.

The cercopithecoid wrist joint differs from the wrist joints of hominoids in several ways. The distal ulna, the distal radius, the pisiform, the triquetrum, the hamate, and the base of the fifth metacarpal are on the one hand remarkably alike among cercopithecoid genera, and on the other remarkably distinct from homologous bones in the Hominoidea. Functionally, the triquetrum and the pisiform, in conjuction with the ulnar styloid process, check the proximal carpal row during ulnar deviation, and are possibly important in stabilizing the wrist during dorsiflexion as well. The head of the ulna almost certainly betokens a range of radioulnar supination in cercopithecoids that is substantially less than is to be found in any of the hominoid genera. The articulation between the hamate bone and the base of the fifth metacarpal allows for considerable dorsiflexion in the Cercopithecoidea; this potential was not evidenct in any of the hominoids examined. Behaviorally, the cercopithecoid wrist can most profitably be viewed as an adaptation for a quadrupedal life style involving dorsiflexion of the wrist and palmigrade/digitigrade substrate contact. The hominoid wrist joint is not adapted for such a behavioral potential.

Animals↗
PubMed1994

Rapid morphological radiation and convergence among races of the butterfly Heliconius erato inferred from patterns of mitochondrial DNA evolution.

The neotropical Heliconius butterflies are famous examples of Müllerian mimicry, due to the diverse array of shared, brightly colored wing patterns that advertise the butterflies' unpalatability. The parallel geographical variation in these patterns within several widespread species has been invoked to support the controversial Pleistocene refugium hypothesis of tropical diversification. However, in no Heliconius species have either evolutionary rates or relationships among geographical races been explicitly examined. I present a phylogenetic hypothesis based on mitochondrial DNA sequences for 14 divergent races of Heliconius erato, which reveals that similar wing patterns have evolved rapidly and convergently within the species. There is a basal split between groups of races from east and west of the Andes, reflecting a vicariant separation at the base of the Pleistocene. Within each of these clades, sequence divergence is very low, and some haplotypes are shared between allopatric races with radically different wing patterns. The topology implies a simultaneous radiation of races in these two areas within the last 200,000 years. Ages for the clades are estimated by comparing sequence divergence to a plot of mitochondrial divergence in several arthropod taxa with independently dated divergence times. This plot is linear and suggests that mitochondrial DNA in arthropods evolves in a clocklike manner, at least initially, when sequence divergence is low.

Animals↗
PubMed2002

Morphology of the external nose in Hipposideros diadema and Lavia frons with comments on its diversity and evolution among leaf-nosed Microchiroptera.

In some bats, a noseleaf is thought to help focus echolocation calls emitted through the nostrils. I studied the ontogenetic mode of the rhinarial cartilages and the associated facial muscles to assess how these rhinarial infrastructures interact with the noseleaf, and the inferred function of such a rhinarial complex. This study focuses on developmental stages of Hipposideros diadema and Lavia frons. Based on new data on these two rhinolophoids and a review of former studies concerning rhinopomatids, rhinolophoids and phyllostomids, the functional and phylogenetic implications of the rhinarial complex among leaf-nosed Microchiroptera are evaluated by the current study. Nasal emitting forms evolved several times independently in the Microchiroptera and share various features, irrespective of their phylogenetic position: the nostrils lie dorsally; the noseleaf has a well-developed horseshoe-shaped plate; the cartilago cupularis bears a large processus cupularis; M(iv) is extended on the lateral plate of the processus alaris superior. The unique similarities of the ontogenetic process of the nasal 'resonators' support the assumption that the rhinolophids + megadermatids and rhinopomatids may represent a natural group. In some features, the rhinolophids + megadermatids differ significantly from the phyllostomids. The noseleaf has a median flap and anterior-facing pockets. The processus alaris superior is half-tube-shaped or included in the lateral wall of the cupula nasi anterior. The cartilago accessoria and the attendant musculature perform an important function for supporting and moving the noseleaf. Similar emission of the echolocation pulses but alternative constructional designs of the external nose structures suggest that a separate history of rhinolophoids and phyllostomids might account for these differences.

Animals↗
PubMed2002

Atypical blasts and bone marrow necrosis associated with near-triploid relapse of acute promyelocytic leukemia after arsenic trioxide treatment.

The pathologic features of acute promyelocytic leukemia (APL) with t(15;17)(q22;q21) are highly characteristic, which with few exceptions enable a firm diagnosis to be made on morphologic grounds. An APL patient in first relapse presented with large, bizarre circulating blasts and bone marrow necrosis 2 weeks after chemotherapy consolidation for an arsenic trioxide-induced remission. Although a morphologic diagnosis could not be reached, cytogenetic investigations showed a near-triploid clone with t(15;17), confirming APL in second relapse. This case showed that clonal evolution with additional karyotypic aberrations might alter the blast morphology and pathologic features in APL.

Adult↗
PubMed2006

Homology and heterochrony: the evolutionary embryologist Gavin Rylands de Beer (1899-1972).

The evolutionary embryologist Gavin Rylands de Beer can be viewed as one of the forerunners of modern evolutionary developmental biology in that he posed crucial questions and proposed relevant answers about the causal relationship between ontogeny and phylogeny. In his developmental approach to the phylogenetic phenomenon of homology, he emphasized that homology of morphological structures is to be identified neither with the sameness of the underlying developmental processes nor with the homology of the genes that are involved in the development of the structures. De Beer's work on developmental evolution focused on the notion of heterochrony, arguing that paedomorphosis increases morphological evolvability and is thereby an important mode of evolution that accounts for the origin of many taxa, including higher taxa.

Animals↗
PubMed2001

Proximodistal domain specification and interactions in developing Drosophila appendages.

The morphological diversification of appendages represents a crucial aspect of animal body plan evolution. The arthropod antenna and leg are homologous appendages, thought to have arisen via duplication and divergence of an ancestral structure (Snodgrass, R. (1935) Book Principles of Insect Morphology. New York: McGraw-Hill). To gain insight into how variations between the antenna and the leg may have arisen, we have compared the epistatic relationships among three major proximodistal patterning genes, Distal-less, dachshund and homothorax, in the antenna and leg of the insect arthropod Drosophila melanogaster. We find that Drosophila appendages are subdivided into different proximodistal domains specified by specific genes, and that limb-specific interactions between genes and the functions of these genes are crucial for antenna-leg differences. In particular, in the leg, but not in the antenna, mutually antagonistic interactions exist between the proximal and medial domains, as well as between medial and distal domains. The lack of such antagonism in the antenna leads to extensive coexpression of Distal-less and homothorax, which in turn is essential for differentiation of antennal morphology. Furthermore, we report that a fundamental difference between the two appendages is the presence in the leg and absence in the antenna of a functional medial domain specified by dachshund. Our results lead us to propose that the acquisition of particular proximodistal subdomains and the evolution of their interactions has been essential for the diversification of limb morphology.

Animals↗
PubMed2025

Isolation and characterization of bacteriophages from clinical enterohemorrhagic Escherichia coli strains.

Temperate bacteriophages play a pivotal role in the biology of their bacterial host. Of particular interest are bacteriophages infecting enterohemorrhagic E. coli (EHEC) due to their significant contribution to the pathogenicity of its host, most notably by encoding the key virulence factor of this pathogen, the Shiga toxin. To better understand the role of EHEC phages on the functionality of its host, we isolated eight temperate phages from clinical EHEC isolates and characterized their genomic composition, morphology, and receptor targeting. Morphological analysis identified one long-tailed siphophage, targeting the OmpC receptor for host recognition, whereas the other seven phages are short-tailed podophages and target the essential BamA protein. Genomic characterization revealed significant variations between the long- and short-tailed phages. Five of the eight isolated phages encode the potent Shiga toxin. Comparative analysis displays the typical lambdoid mosaicism, indicative of horizontal gene transfer driving evolution. These findings provide insights into the genetic and morphologic diversity and receptor specificity of EHEC phages, highlighting their role in the evolution and pathogenicity of clinical EHEC strains.IMPORTANCECharacterizing bacteriophages from clinical EHEC isolates is crucial in understanding the mechanisms underlying bacterial evolution and virulence. Despite the clinical relevance of EHEC bacteriophages, they remain underexplored, and particularly phage receptors are often not characterized. Studying temperate EHEC phages is essential in the development of strategies to address the global burden of these foodborne infections. Notably, identifying the phage receptors is critical in unraveling the specific interaction between phage and host. Knowledge of the phage receptors can provide insights into the mechanisms of phage infection, host range, and bacterial resistance and is fundamental in the design of targeted therapies like new antimicrobials, phage therapy, or prevention of those infections.

Humans↗
PubMed2003

Anatomical study of human adductor hallucis muscle with respect to its origin and insertion.

The adductor hallucis muscle (ADH) is evolutionally and functionally important, but no detailed morphological data about this muscle in the human body is available. In the present study, we examined the origin and insertion of the oblique and transverse heads of the ADH. Forty-five feet (20 right, 25 left) of 34 cadavers (13 men, 21 women, average age of 80 years old) were used in the present study. The origin, insertion and nerve supplies of the oblique and transverse heads of the ADH were macroscopically examined in detail. Most commonly, the oblique head of the ADH arose from the bases of the 2nd, 3rd and 4th metatarsal bones, the plantar metatarsal ligaments spanned between the bases of the 2nd, 3rd and 4th metatarsal bones, the lateral cuneiform bone, the fibrous sheath of the tendon of the peroneus longus muscle and the long plantar ligament, and inserted into the lateral sesamoid bone of the great toe and the capsule of the 1st metatarsophalangeal joint. Most commonly, the transverse head of the ADH originated from the capsules of the 3rd and 4th (and occasionally 5th) metatarsophalangeal joint and the deep transverse metatarsal ligaments, and inserted into the lateral sesamoid bone of the great toe, the capsule of the 1st metatarsophalangeal joint and lateral surface of the base of the 1st proximal phalanx. This muscle was classified into four types based on the origin of its oblique head and was classified into three types based on the origin of its transverse head. The percent ratio of the weight of the oblique head to the total weight of all the intrinsic muscles of the foot was 9.4% +/- 1.5, and the transverse head was 1.5% +/- 0.6 (n = 14). The transverse head of ADH tends to be reduced in size in the human, but the oblique head is well developed with no sign of reduction.

Aged↗
PubMed2003

Morphology and histology of chimpanzee primary visual striate cortex indicate that brain reorganization predated brain expansion in early hominid evolution.

Human brain evolution is characterized by an overall increase in brain size, cerebral reorganization, and cerebral lateralization. It is generally understood when brain enlargement occurred during human evolution. However, issues concerning cerebral reorganization and hemispheric lateralization are more difficult to determine from brain endocasts, and they are topics of considerable debate. One region of the cerebral cortex that may represent the earliest evidence for brain reorganization is the primary visual cortex (PVC), or area 17 of Brodmann. In nonhuman primates, this region is larger in volume (demarcated anteriorly by the lunate sulcus), and extends further rostrally than it does in modern humans. In early hominid fossil (Australopithecus) endocasts, this region appears to occupy a smaller area compared to that in nonhuman primates. Some have argued that the brain first underwent size expansion prior to reorganization, while others maintain that reorganization predated brain expansion. To help resolve this question, we provide a description of two male, common chimpanzee (Pan troglodytes) brains, YN77-111 and YN92-115, which clearly display a more posterior lunate sulcal morphology than seen in other chimpanzees. These data show that neurogenetic variability exists in chimpanzees, and that significant differences in organization (e.g., a reduced PVC) can predate brain enlargement. While the human brain has experienced numerous expansion and reorganization events throughout evolution, the data from these two chimpanzees offer significant support for the hypothesis that the neurogenetic basis for brain reorganization was present in our early fossil ancestors (i.e., the australopithecines) prior to brain enlargement.

Animals↗
PubMed1997

Organization of the Fugu rubripes Hox clusters: evidence for continuing evolution of vertebrate Hox complexes.

The clustered organization of Hox genes provides a powerful opportunity to examine gene gain and loss in evolution because physical linkage is a key diagnostic feature which allows homology to be established unambiguously. Furthermore, Hox genes play a key role in determination of axial and appendicular skeletal morphology and may be a key component of the evolution of diverse metazoan body forms. Despite suggestions that changes in Hox gene number played a role in evolution of metazoan body plans, there has been a general lack of evidence for such variation amongst gnathostomes (or indeed any vertebrate) and it has therefore been widely assumed that differential regulation may be the key element in all vertebrate Hox evolution. We have studied the Hox gene clusters of a teleost fish, Fugu rubripes, to test the possibility that Hox organization may have varied since the origin of jawed vertebrates. We have identified four Hox complexes in Fugu and found an unprecedented degree of variation when compared with tetrapod clusters. Our data show that: Fugu clusters are widely variant with respect to length; at least nine genes have been lost; there is a new group-2 paralogue; and pseudo-gene remnants of group-1 and group-3 paralogues were found in the Hoxc complex, when compared with the present mammalian clusters. We show that gene loss after duplication of the prototypical vertebrate Hox clusters is a key feature of both tetrapod and fish evolution.

Amino Acid Sequence↗
PubMed2001

The origin and evolution of the woolly mammoth.

The mammoth lineage provides an example of rapid adaptive evolution in response to the changing environments of the Pleistocene. Using well-dated samples from across the mammoth's Eurasian range, we document geographical and chronological variation in adaptive morphology. This work illustrates an incremental (if mosaic) evolutionary sequence but also reveals a complex interplay of local morphological innovation, migration, and extirpation in the origin and evolution of a mammalian species. In particular, northeastern Siberia is identified as an area of successive allopatric innovations that apparently spread to Europe, where they contributed to a complex pattern of stasis, replacement, and transformation.

Africa↗
PubMed1990

[Quantitative changes of the blood serum immunoglobulins in patients with diabetes mellitus types I and II and microangiopathy detected by morphologic study].

A study was made of the immunological mechanisms implicated in the evolution of diabetic microangiopathy. For this purpose in 270 patients with type I and II diabetes mellitus, the concentration of IgA, IgM and IgG was measured and compared with morphological alterations in skin biopsy specimens. The control group was made up of 30 normal persons (donors). The sections were stained with conventional methods, which made it possible to reveal by light microscopy the correlation between the intensity of diabetic microangiopathy and the rise of the IgG level.

Adolescent↗