Mirror Duplication Research Articles

Nervous system and tissue polarity dynamically adapt to new morphologies in planaria

The coordination of tissue-level polarity with organism-level polarity is crucial in development, disease, and regeneration. Here, we characterize a new example of large-scale control of dynamic remodeling of body polarity. Exploiting the flexibility of the body plan in regenerating planarians, we used mirror duplication of the primary axis to show how established tissue-level polarity adapts to new organism-level polarity. Characterization of epithelial planar cell polarity revealed a remarkable reorientation of tissue polarity in double-headed planarians. This reorientation of cilia occurs even following irradiation-induced loss of all stem cells, suggesting independence of the polarity change from the formation of new cells. The presence of the two heads plays an important role in regulating the rate of change in overall polarity. We further present data that suggest that the nervous system itself adapts its polarity to match the new organismal anatomy as revealed by changes in nerve transport driving distinct regenerative outcomes. Thus, in planaria tissue-level polarity can dynamically reorient to match the organism-level anatomical configuration.

Self-absorbed Al lines in laser-induced plasma

Self-reversed line profiles of Al 3s23p → 3s24s transitions in a laser ablation plasma are considered following plasma initiation on the surface of an Al alloy target. Experimental self-absorption correction factors are tabulated by measuring plasma line profiles with and without its reflection using the mirror duplication method. At a delay of 60 ns, measured line profiles 0.5 mm from the Al surface show self-reversed line profiles. Corrected line widths are determined to be 1.1 ± 0.2 and 1.7 ± 0.2 nm for the 394.4 and 396.15 nm lines, respectively, following fitting with a Voigt line profile. Ne are determined to be 3.8 ± 0.4 and 10 ± 1 × 1018 cm−3, respectively.

A Rare Syndrome of Five Finger Hands and Polydactyly of the Feet: A Case Report

Combination of multiple congenital anomalies in the upper and lower limbs is an uncommon clinical presentation. Al-Qattan et al have indicated that the presence of double ulna is not mandatory to make the diagnosis of mirror hand. The absence of the thumb and the presence of the five-fingered hand and hypoplastic radius might be considered as an atypical mirror hand anomaly [1]. There are several definitions for the mirror foot anomaly including a foot with mirror image polydactyly, a foot with supernumerary rays with the characteristics of the post-axial toes situated medial to the first ray (preaxialy), and mirror duplication of the all skeletal structures on the tibial aspect of the foot [2]. This report presents a rare syndrome in a 22-year-old man who presented with five finger hands and polydactyly of his feet. The radius and the radial carpal bones were hypoplastic on both sides. The anomalies might be a rare syndrome of atypical mirror hands and mirror feet.

The proximal chromosome 14q microdeletion syndrome: Delineation of the phenotype using high resolution SNP oligonucleotide microarray analysis (SOMA) and review of the literature

We report on two patients with overlapping small interstitial deletions involving regions 14q12 to 14q13.1. Both children had severe developmental delay, failure to thrive, microcephaly, and distinctive facial features, including abnormal spacing of the eyes, epicanthal folds, sloping forehead, low-set ears, rounded eyebrows with triangular media aspect and outer tapering, depressed and broad nasal bridge, small mouth, a long philtrum, and a prominent Cupid's bow. Brain MRI of both children showed partial agenesis of the corpus callosum. Our first patient had bilateral hypoplastic optic nerves causing blindness, mild hearing impairment, sinus arrhythmia, abnormal temperature regulation, frequent apneic episodes, myoclonic jerks, and opisthotonus. Our second patient had a seizure disorder confirmed by EEG, sleep apnea, chronic interstitial lung disease, and several episodes of pneumonia and gastroenteritis. Cytogenetic analysis showed a normal karyotype in Patient 1 and a unique apparently balanced three-way translocation in Patient 2 involving chromosomes 4, 14, and 11. High resolution SNP Oligonucleotide Microarray Analysis (SOMA) revealed a deletion in the proximal region of chromosome 14q overlapping with the deletion of our first patient, and no copy number changes in chromosomes 4 and 11. Here, we review and compare published cases with a deletion involving the 14q12-22.1 chromosomal region in an effort to correlate phenotype and genotype. We also examine the underlying genomic architecture to identify the possible mechanism of the chromosomal abnormality. Our review found a patient with a mirror duplication of our first patient's deletion, confirming the existence of an underlying genomic structural instability in the region. © 2011 Wiley-Liss, Inc.

Morphogenetic bases and parametric system of trichome evolution in plants of the genus Draba L.

Using quantitative morphological analysis of light microscopy data, the normal variation of trichome morphogenesis is studied in six whitlow grass species (Draba L.) and the morphological variation of adult trichomes in 11 species. The evolution consists in the transition from a radial morphogenesis pattern to bilateral and replacement of complex (branched) trichome rays with simple (unbranched) rays. A parametric system is constructed for classification of the ray morphology; this system includes two parameters-the ratio of the numbers of complex to simple rays, characterizing the probability of secondary branching of primary buds, and the number of primary buds, characterizing the probability of primary branching on the surface of the trichome cell. In this parametric space, all of the studied species fit well a third-order curve consisting of two ascending branches displaying a positive correlation between the primary and secondary branchings and a descending branch, located between them, where the primary and secondary branches are negatively correlated. The deduced evolutionary direction is almost independent of the size of the trichome cells and is explained exclusively by the mechanics of morphogenesis: acceleration in the development of the primary bud of the ray decreases the probability of its own branching and creates additional elastic extension of the cell surface, preventing other buds from branching. The morphogenesis itself appears to be a mechanically nonholonomic system, filtering in a selective manner the fluctuations of the same sign, which explains the directed pattern of its evolution. In the evolutionarily initial state, trichome ontogenesis is absent because its modules (primary buds) are formed by a mirror duplication. The ontogenesis commences when mirror symmetry in the formation of modules is lost and replaced with an axial pattern; thus, the change in the morphological type of buds is a direct consequence of the emergence of ontogenesis and its further evolution. Its main material is intraindividual variation, the only source of which is the mechanics of morphogenesis itself. It is found that morphological evolution can take place at an initially zero heritability and zero adaptive value of morphological differences.

Mirror duplication of chromosome 21 with complete phenotype of Down syndrome

Mirror duplication of chromosome 21 with complete phenotype of Down syndrome

Polydactylie complexe des membres : le pied en miroir. À propos de deux cas et revue de la littérature

Polydactyly is the most common congenital limb anomaly occurring both as an isolated defect or as part of a syndrome. However mirror foot is an exceptional abnormality (14 cases reported). The authors describe two sporadic cases of mirror foot. The first case presents a mirror polydactyly of the left foot, an hexadactyly of the right foot and a central polysyndactyly of both hands. The second case presents a mirror polydactyly of both feet. Mirror foot is a very rare defect. Both sporadic and familiar cases have been reported. This malformation can affect one or both feet. Some cases are associated with other congenital anomalies. The definition of mirror foot is warying according to the authors and the review of literature shows an important variability in the patterns of mirror polydactyly. Mirror duplication of hands and feet result of aberrant positioning of the zone of polarizing activity in relation to the apical ectodermal ridge during limb bud development. Different genes encoding limb pattern have been described.

Anatomy of a duplicated human foot from a limb with fibular dimelia

At birth, a patient presented with a right lower limb featuring preaxial polydactyly and fibular dimelia with a complete absence of the tibia. Radiographic studies of the patient's foot revealed a duplicated tarsus with eight metatarsals and toes. The three preaxial toes were surgically removed at 1 year of age. A hallux and four normal-appearing postaxial toes remained. The foot was amputated when the patient was 3 years old. Dissection of the amputated foot revealed that the muscles of the dorsum were normal, except that the tendon of the extensor hallucis brevis muscle inserted into both the hallux and toe 2, rather than only into the hallux. The few abnormalities observed among the muscles on the plantar surface of the foot included absence of the insertions of the tibialis posterior and the abductor hallucis muscles. In addition, the two heads of the adductor hallucis muscle inserted abnormally into the medial (tibial) side of metatarsal 1, rather than into the lateral side. These various muscular anomalies, in addition to the mirror duplication of the foot with the presence of only a single metatarsal 1, leads us to propose that this metatarsal probably represents two lateral (fibular) halves that form a laterally duplicated bone. Although the dorsalis pedis artery was present on the dorsal surface of the foot, most of its derivatives were absent. This artery did give rise to a supernumerary medial branch that ended abruptly in the connective tissue (presumably postsurgical scar) at the medial border of the foot. This branch may have represented a duplicated dorsalis pedis artery associated with the duplicated preaxial portion of the foot. The arteries on the plantar surface of the foot were normal. Even though some anomalies in the pattern of the cutaneous innervation were observed, the nerves of the foot were largely normal. The gross and radiographic anatomy of this specimen and the radiographic anatomy of the leg suggest that some teratogenic event occurred when developmental specification reached the level of the future knee. The teratogenic event, which probably occurred early in the fifth week of development, may have caused damage that led to a lateral duplication of both the leg and the foot with the absence of some of the most medial structures. Teratology 60:272–282, 1999. © 1999 Wiley-Liss, Inc.

A dicephalic monster embryo ofDrosophila melanogaster.

A monster embryo with a head on each end developed from an abnormalDrosophila egg produced by a M(1)oSp/Binsn female. The embryo probably represents a longitudinal mirror duplication of head and all 3 thoracic segments. The significance of this type of pattern anomaly for embryonic pattern specification inDrosophila is discussed.