scholarly journals Superficially Similar Adaptation Within One Species Exhibits Similar Morphological Specialization but Different Physiological Regulations and Origins

2020 ◽  
Vol 8 ◽  
Author(s):  
Yi Zhang ◽  
Xing-Xing Wang ◽  
Zhu-Jun Feng ◽  
Hao-Su Cong ◽  
Zhan-Sheng Chen ◽  
...  
Keyword(s):  
Morphological Specialization

Functional design of microvilli in the Malpighian tubules of the insect Rhodnius prolixus

1983 ◽  
Vol 60 (1) ◽  
pp. 117-135
Author(s):  
T.J. Bradley
Keyword(s):  
Plasma Membranes ◽  
Current Knowledge ◽  
Morphological Difference ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Free Standing ◽  
Narrow Channels ◽  
Morphological Specialization ◽  
Mitochondrial Volume ◽  
The Mean

The Malpighian tubules of Rhodnius prolixus are divided into two regions; the upper tubule, which is the site of isosmotic secretion and haemolymph filtration, and the lower tubule where water and KCl are resorbed. In the upper tubule the microvilli are arranged in clumps consisting of several hundred microvilli lying closely parallel. The microvillar plasma membranes do not touch but are held approximately equal to 16 nm apart along the full length of the microvilli. As a consequence, the extracellular space between the microvilli consists of long narrow channels. A morphometric analysis of extracellular, cytoplasmic, endoplasmic reticular and mitochondrial volume within the clumps was conducted. Using the secretion rate of the epithelium and the channel dimensions, it was calculated that the mean residence time for secreted fluid in the intermicrovillar spaces was approximately equal to 0.4s. In view of our current knowledge of the physiology and morphology of the upper tubule, it is argued: (1) that osmotically driven water passes principally through the cells, not the junctional spaces; and (2) that the microvillar clumps are a morphological specialization, which serves to maximize solute-water coupling in the upper tubule. The microvilli in the lower tubule are free-standing, with no pattern of clumping as in the upper tubule. The axopods are about twice as long as the microvilli (10-14 micron) and are found in all regions of the lower tubule. This is in agreement with the proposal that the motile axopods serve to propel uric acid crystals through the lower tubule. No morphological difference was found between the upper and lower halves of the lower tubule, although the two portions are known to be physiologically distinct.

Study of yolk-sac endoderm organogenesis in the chick using a specific enzyme (cysteine lyase) as a marker of cell differentiation

Development ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 159-174
Author(s):  
Nelly Bennett
Keyword(s):  
Cell Differentiation ◽  
Blood Cells ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Specific Enzyme ◽  
Cell Proliferation And Differentiation ◽  
Lyase Activity ◽  
Morphological Specialization

The detection of a specific enzyme (cysteine lyase) of the yolk-sac endoderm by a very sensitive method is employed to characterize cell differentiation during the early stages of endoderm organogenesis in the chick. The first cells to contain active cysteine lyase are found in the germ wall at the primitive streak stage. In vivo observations establish a relation between the morphological specialization and organization of endodermal cells, their loss of mitotic activity and the increase in cysteine lyase activity. They suggest an influence of the mesoderm on endoderm differentiation. In vitro experiments confirm the existence in the yolk-sac endoderm of an incompatibility between cell proliferation and differentiation, as well as the action of the mesoderm on both the structural organization of the endoblast and the appearance of cysteine lyase; this last action seems to be due mainly to blood cells; chicken and rabbit blood cells are equally active. The problems of the origin of the endoderm and of the interactions occurring during the organogenesis of the yolk-sac endoderm are discussed.

scholarly journals Wind, Waves, and Wing Loading: Morphological Specialization May Limit Range Expansion of Endangered Albatrosses

PLoS ONE ◽  
2008 ◽  
Vol 3 (12) ◽  
pp. e4016 ◽  
Author(s):  
Robert M. Suryan ◽  
David J. Anderson ◽  
Scott A. Shaffer ◽  
Daniel D. Roby ◽  
Yann Tremblay ◽  
...  
Keyword(s):  
Range Expansion ◽  
Wind Waves ◽  
Wing Loading ◽  
Morphological Specialization

scholarly journals Morphological specialization of heterantherous Rhynchanthera grandiflora (Melastomataceae) accommodates pollinator diversity

Plant Biology ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 583-590 ◽  
Author(s):  
S. Konzmann ◽  
F. Hilgendorf ◽  
C. Niester ◽  
A. R. Rech ◽  
K. Lunau
Keyword(s):  
Pollinator Diversity ◽  
Morphological Specialization

scholarly journals Morphology of a new blister beetle (Coleoptera, Meloidae) larval type challenges the evolutionary trends of phoresy-related characters in the genus Meloe

Entomologia ◽  
2014 ◽  
Author(s):  
A. Di Giulio ◽  
M. Carosi ◽  
R. Khodaparast ◽  
M.A. Bologna
Keyword(s):  
Evolutionary Trends ◽  
Morphological Comparison ◽  
Incertae Sedis ◽  
Larval Type ◽  
First Instar ◽  
Morphological Specialization ◽  
Alternative Scenarios ◽  
Blister Beetle

The discovery of some specimens of a new first instar larval type in blister beetles, collected in Iran on Anthophora bees, confirms the existence of repetitive and parallel trends in morphological specialization to phoresy in distinct lineages of Meloidae and in particular in the subfamily Meloinae. The new Iranian larva, herein described and illustrated, shows several characters and a peculiar phoretic strategy that closely parallel that of the Meloe subgenus Lampromeloe, with similar modifications of the fronto-clypeal setae into strong lanceolate spines used to pierce the intersegmental membranes of the bees. Both parallel and shared derived evolution of these characters seem possible. The coexistence in this larva of characters in both primitive and derived state is of particular interest in order to analyse the different rates and trends of evolution of phoretic adaptations. A morphological comparison (SEM) of this new meloine larva (incertae sedis), tentatively assignable to Meloe, with the M. (Lampromeloe) larvae is carried out in order to discuss the evolutionary implications of its placement in Lampromeloe, and the relative characters that would support it, vs other possible alternative scenarios.

scholarly journals Early Morphological Specialization for Insect-Spider Associations in Mesozoic Lacewings

2016 ◽  
Vol 26 (12) ◽  
pp. 1590-1594 ◽  
Author(s):  
Xingyue Liu ◽  
Weiwei Zhang ◽  
Shaun L. Winterton ◽  
Laura C.V. Breitkreuz ◽  
Michael S. Engel
Keyword(s):  
Morphological Specialization

scholarly journals STUDIES ON CILIA

1965 ◽  
Vol 26 (3) ◽  
pp. 805-834 ◽  
Author(s):  
Peter Satir
Keyword(s):  
Cross Section ◽  
Length Change ◽  
The Body ◽  
Cell Of Origin ◽  
Ciliary Movement ◽  
The Matrix ◽  
Morphological Specialization ◽  
Dense Band ◽  
The Cross ◽  
Different Order

Termination of peripheral filaments of the axoneme of gill cilia of fresh-water mussels (Elliptio or Anodonta) occurs in characteristic fashion: (a) subfiber b of certain doublets ends leaving a single simplified tubular unit; (b) the wall of the unit becomes thick and may even obliterate the interior; and (c) the filament drops out of the 9 + 2 pattern. The order in which doublets begin simplifying is also characteristic. This may be determined by numbering the filaments, those with the bridge being 5–6, with the direction of numbering determined by the apparent enantiomorphic configuration (I to IV) of the cross-section. Shorter filaments can be identified in simplifying tips with mixed double and single peripheral units. In this material, laterofrontal cirri show a morphological specialization in the region where individual cilia simplify. The cilia studied run frontally from the body of the cirrus and point in the direction of effective stroke. The longest filaments (Nos. 3, 4, 5, 6, 7) appear as the doublets at the bottom of the cross-section, nearest the surface of the cell of origin. Above them, and above the central pair, a dark band (a section of a dense rod) runs through the matrix. The remaining filaments are the single units. Effective-pointing frontal and lateral ciliary tips end in a fashion similar to laterofrontal tips, although no dense band is present. For all effective-pointing tips studied, the order in which the peripheral filaments end appears to be Nos. (9, 1), 8, 2, 7, 6, 3, 4, 5. However, recovery-pointing lateral tips show a different order: Nos. 7, 6, 8, 5, 9, 4, 1 (3, 2), although the longer filaments are still at the bottom of the cross-section. In simple models of ciliary movement involving contraction of the peripheral filaments, filaments at the top of the cross-section should be longer, if any are. Such models are not supported by the evidence here. These results can be interpreted as supporting sliding-filament models of movement where no length change of peripheral filaments occurs.

The kinematics and performance of escape responses of the knifefish Xenomystus nigri

1993 ◽  
Vol 71 (1) ◽  
pp. 189-195 ◽  
Author(s):  
M. A. Kasapi ◽  
P. Domenici ◽  
R. W. Blake ◽  
D. Harper
Keyword(s):  
High Speed ◽  
Longitudinal Axis ◽  
The Body ◽  
Maximum Acceleration ◽  
Low Speed ◽  
Average Maximum ◽  
Morphological Specialization ◽  
Escape Responses ◽  
And Performance ◽  
Stage 1

The kinematics and performance of the escape responses of the knifefish Xenomystus nigri, a fish specialized for low-speed, undulatory median-fin propulsion, were recorded by means of high-speed cinematography. Two types of escape were observed, one involving the formation of a C-shape along the longitudinal axis of the fish (stage 1), followed by a slow recoil of the body (single bend); the other (double bend) involved stage 1 followed by a contralateral bend (stage 2). The pectoral fins were extended throughout escapes of both types. The average maximum acceleration for double bend escapes was 127.98 m∙s−2; acceleration was usually greatest in stage 1. In double bend escapes, turning angles for stages 1 and 2 were not correlated. Pitch and roll orientations change during escapes. In stage 1, the average roll and average pitch were linearly correlated, suggesting that roll was partly responsible for establishing pitch. Knifefish achieved high maximum acceleration relative to other fish. Therefore, performance was not compromised by morphological specialization for low-speed swimming; however, a negative correlation of pitch with acceleration in stage 1 suggested that escapes involve a trade-off between acceleration and confusing a predator by changing planar orientation.

MORPHOLOGICAL SPECIALIZATION AS A MACROEVOLUTIONARY RATCHET IN CARNIVORES

2018 ◽  
Author(s):  
Blaire Van Valkenburgh ◽  
◽  
Mairin Balisi ◽  
Mark Juhn
Keyword(s):  
Morphological Specialization
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