The mis-expression of posterior Hox-4 genes in talpid (ta3) mutant wings correlates with the absence of anteroposterior polarity

Development ◽  
1992 ◽  
Vol 114 (4) ◽  
pp. 959-963 ◽  
Author(s):  
J.C. Izpisua-Belmonte ◽  
D.A. Ede ◽  
C. Tickle ◽  
D. Duboule
Keyword(s):  
Anteroposterior Axis ◽  
Morphological Differences ◽  
Anteroposterior Polarity

Developing chicken wings homozygous for the talpid (ta3/ta3) mutation are polydactylous and have defects in the establishment of their anteroposterior polarity. We analysed the expression domains of the posteriorly restricted homeobox Hox-4 genes in such mutant wings. The Hox-4 genes are now expressed right across the anteroposterior axis instead of being expressed just posteriorly. This correlates well with the absence of clear morphological differences between the talpid3 digits and reinforces the idea that vertebrate Hox-4 genes are involved in setting up the limb anteroposterior asymmetry.

A scanning electron microscopic study of the eggs of Culicoides variipennis (Diptera: Ceratopogonidae)

1987 ◽  
Vol 45 ◽  
pp. 884-885 ◽  
Author(s):  
R. A. Nunamaker ◽  
C. E. Nunamaker ◽  
B. C. Wick
Keyword(s):  
Distinct Species ◽  
Hemorrhagic Disease ◽  
Insect Vector ◽  
Electron Microscopic ◽  
Important Species ◽  
Scanning Electron Microscopic Study ◽  
Laboratory Colony ◽  
Culicoides Variipennis ◽  
Morphological Differences ◽  
Scanning Electron

Culicoides variipennis (Coquillett) is probably the most economically important species of biting midge in the U.S. due to its involvement in the transmission of bluetongue (BT) disease of sheep, cattle and ruminant wildlife, and epizootic hemorrhagic disease (EHD) of deer. Proposals have been made to recognize the eastern and western populations of this insect vector as distinct species. Others recommend use of the term “variipennis complex” until such time that the necessary biosystematic studies have been made to determine the genetic nature and/or minute morphological differences within the population structure over the entire geographic range of the species. Increasingly, students of ootaxonomy are relying on scanning electron microscopy (SEM) to assess chorionic features. This study was undertaken to provide comparative chorionic data for the C. variipennis complex.Culicoides variipennis eggs were collected from a laboratory colony maintained in Laramie, Wyoming.

Morphologic differences between abdominal and inguinal testes in stallions

1987 ◽  
Vol 45 ◽  
pp. 820-821
Author(s):  
F. Al-Bagdadi ◽  
D. Hoyt ◽  
P. Karns ◽  
G. Martin ◽  
M. Memon ◽  
...  
Keyword(s):  
Carcinoma Cells ◽  
Genital System ◽  
Diagnosis And Prognosis ◽  
Male Genital System ◽  
Morphological Differences ◽  
Hormone Imbalance ◽  
Made In ◽  
Male Genital

The most frequently occuring abnormality of the male genital system in mammals is the failure of one or both testes to descend into the scrotum. The reasons for abdominal or inguinal retention of testes could be anatomic malformation, faulty development or hormone imbalance.Cryptorchidism has been associated with either greatly reduced or absent spermatogenesis (Kaueakami et al, 1984), and being a source of neoplasia. According to Stick (1980), germinal carcinoma cells have been believed to be the cause of teratomas in equine cryptorchid testicles. Neoplasia has been reported in descended testes of unilateral cryptorchid patients (Martin et al, 1981).No distinction has been made in relating the problem of cryptorchid testes to inguinal or abdominal retention. The purpose of this study is to record the morphological differences between inguinal and abdominal cryptorchid testes as an aid in diagnosis and prognosis.

Observation of pseudo 10-fold symmetry in the ordered iron-zinc delta phase

1992 ◽  
Vol 50 (1) ◽  
pp. 36-37
Author(s):  
L. A. Giannuzzi ◽  
A. S. Ramani ◽  
P. R. Howell ◽  
H. W. Pickering ◽  
W. R. Bitler
Keyword(s):  
Single Phase ◽  
X Ray Diffraction ◽  
Rich Region ◽  
Average Cell ◽  
X Ray ◽  
Delta Phase ◽  
Cell Dimensions ◽  
Δ Phase ◽  
Morphological Differences ◽  
Concentration Discontinuity

The δ phase is a Zn-rich intermetallic, having a composition range of ∼ 86.5 - 92.0 atomic percent Zn, and is stable up to 665°C. The stoichiometry of the δ phase has been reported as FeZn7 and FeZn10 The deviation in stoichiometry can be attributed to variations in alloy composition used by each investigator. The structure of the δ phase, as determined by powder x-ray diffraction, is hexagonal (P63mc or P63/mmc) with cell dimensions a = 1.28 nm, c = 5.76 nm, and 555±8 atoms per unit cell. Later work suggested that the layer produced by hot-dip galvanizing should be considered as two distinct phases which are characterized by their morphological differences, namely: the iron-rich region with a compact appearance (δk) and the zinc-rich region with a columnar or palisade microstructure (δp). The sub-division of the δ phase was also based on differences in diffusion behavior, and a concentration discontinuity across the δp/δk boundary. However, work utilizing Weisenberg photographs on δ single crystals reported that the variation in lattice parameters with composition was small and hence, structurally, the δk phase and the δp phase were the same and should be thought of as a single phase, δ. Bastin et al. determined the average cell dimensions to be a = 1.28 nm and c = 5.71 nm, and suggested that perhaps some kind of ordering process, which would not be observed by x-ray diffraction, may be responsible for the morphological differences within the δ phase.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Morphological differences in individuals with lip competence and incompetence based on electromyographic diagnosis

2000 ◽  
Vol 27 (10) ◽  
pp. 893-901 ◽  
Author(s):  
K. Yamaguchi ◽  
Y. Morimoto ◽  
R. S. Nanda ◽  
J. Ghosh ◽  
K. Tanne
Keyword(s):  
Morphological Differences

Haemostatic Clot Formation at Anastomosis of Synthetic Venous Graft in Defibrinogenated Dogs: A Scanning Electron Microscopic Study

1981 ◽  
Vol 45 (03) ◽  
pp. 276-281 ◽  
Author(s):  
S Ishimaru ◽  
E Berglin ◽  
H-A Hansson ◽  
A-C Teger-Nilsson ◽  
G William-Olsson
Keyword(s):  
Vena Cava ◽  
Treated Group ◽  
Control Group ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic Study ◽  
Fibrin Network ◽  
Scanning Electron Microscopic ◽  
Expanded Polytetrafluoroethylene Graft ◽  
Morphological Differences ◽  
Scanning Electron

SummaryA segment of the inferior vena cava was replaced by an expanded polytetrafluoroethylene graft in 13 dogs. Five of them served as a control group, while the other 8 were moderately or severely defibrinogenated with subcutaneous batroxobin. Plasma fibrinogen decreased to extremely low values throughout the experiment in the defibrinogenated dogs except in the moderately treated group in which it temporarily rose to 0.72-0.87 g/1 on the first postoperative day.Scanning electron microscopic observations of the haemostatic clot formed at the anastomoses of the graft revealed no significant morphological differences in platelet adhesion and/or aggregation between the three groups. These findings confirmed that platelets play a key role in primary haemostasis during defibrinogenation.The fibrin network was slightly diminished and only short fibrin filaments could be seen in the moderately and severely defibrinogenated groups respectively. These differences in composition of the clots are discussed in relation to their haemostatic capacity.

A new species of Contomastix (Squamata, Teiidae) supported by total evidence, with remarks on diagnostic characters defining the genus

2019 ◽  
pp. 23-36
Author(s):  
Mario. R. Cabrera
Keyword(s):  
New Species ◽  
Geographic Distribution ◽  
Phylogenetic Reconstruction ◽  
Total Evidence ◽  
Molecular Evidence ◽  
Proximal Margin ◽  
Diagnostic Characters ◽  
Morphological Differences ◽  
A New Species ◽  
Molecular Characters

Formerly Cnemidophorus was thought to be the most speciose genus of Teiidae. This genus comprised four morphological groups that were later defined as four different genera, Ameivula, Aurivela, Cnemidophorus and Contomastix. The last appears as paraphyletic in a recent phylogenetic reconstruction based on morphology, but monophyletic in a reconstruction using molecular characters. Six species are allocated to Contomastix. One of them, C. lacertoides, having an extensive and disjunct geographic distribution in Argentina, Uruguay and Brazil. Preliminary analyses revealed morphological differences among its populations, suggesting that it is actually a complex of species. Here, we describe a new species corresponding to the Argentinian populations hitherto regarded as C. lacertoides, by integrating morphological and molecular evidence. Furthermore, we demonstrate that the presence of notched proximal margin of the tongue is a character that defines the genus Contomastix.

Notes on the molecular taxonomy of the Proclossiana eunomia complex (Lepidoptera, Nymphalidae: Argynnini): analysis of DNA barcodes

2018 ◽  
Vol 8 (1) ◽  
pp. 222-232 ◽  
Author(s):  
R. V. Yakovlev ◽  
N. A. Shapoval ◽  
G. N. Kuftina ◽  
A. V. Kulak ◽  
S. V. Kovalev
Keyword(s):  
Body Size ◽  
Molecular Taxonomy ◽  
Taxonomic Status ◽  
Molecular Data ◽  
Coi Gene ◽  
Wing Pattern ◽  
Molecular Approach ◽  
Dna Barcodes ◽  
Morphological Differences ◽  
Proclossiana Eunomia

The Proclossiana eunomia (Esper, 1799) complex is currently composed of the several subspecies distributed throughout Palaearсtic region and North America. Despite the fact that some of the taxa have differences in wing pattern and body size, previous assumptions on taxonomy not supported by molecular data. Therefore, the identity of certain populations of this complex has remained unclear and the taxonomic status of several recently described taxa is debated. Here, we provide insights into systematics of some Palaearctic members of this group using molecular approach, based on the analysis of the barcoding fragment of the COI gene taking into account known morphological differences.

Alkaliphilic species Euastrum lacustre (Charophyta, Zygnematophyceae), first record from Russia

2020 ◽  
Vol 54 (2) ◽  
pp. 313-320
Author(s):  
O. V. Anissimova
Keyword(s):  
Cell Wall ◽  
New Species ◽  
First Record ◽  
European Russia ◽  
Similar Species ◽  
Morphological Differences ◽  
First Time ◽  
Kursk Region

Euastrum lacustre is reported for Russia for the first time. This alcaliphilic species was found in the periphyton and plankton of three lakes in the Kursk Region (European Russia). A description of morphology, including the relief of cell wall, and habitats where this taxon is found are represented. LM and SEM microphotographs are provided. Morphological differences of E. lacustre from similar species are discussed. New species for region, namely Closterium aciculare, Cosmarium formosulum, C. granatum, C. pseudoinsigne, C. reniforme and Staurastrum pingue, are found in the samples together with E. lacustre.

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