Anatomical adaptations in aquatic and wetland dicot plants: Disentangling the environmental, morphological and evolutionary signals

Anatomical, morphological, physiological and biochemical adaptations of leaf as the most ecologically sensitive organ in the species P. tobira and P. heterophyllum, grown in the zones of greenhouse complex with different degree of illumination (1 zone – the level of illumination is 100–300 lx, zone 2 – 3000–7000 lx, and zone 3 – more than 10 thousand lx).) were studied. We revealed the structural morphological and anatomical adaptations, which manifested in the increase of leaf structure xeromorphy (thickening of the leaf, adaxial epidermis and columnar parenchyma, increasing pubescence density) under conditions of high insolation. With a low level of illumination in plants of both species, the thickness of the lamina decreased, mainly due to the mesophyll – the number of layers of the columnar parenchyma and the size of the cells reduced. Interspecific differences in the content of photosynthetic pigments in both species studied were found. A common trend in plants under low light conditions was decrease of chlorophyll a compared with the control, whereas the concentration of chlorophyll b in the leaves of plants increased with shading and high insolation. The result of the adaptation of the photosynthetic apparatus of Pittosporum plants, which normalizes its functioning, is a decreasing chlorophyll index both during shading and intense solar radiation. The maximum is determined in the range of 3–7 thousand lx. Such light regime is optimal for plants of the species studied. The observed decreasing pigment index in P. heterophyllum leaves is considered as an adaptive response of more light-loving species of the genus to their cultivation in the shade. The dependence of the peroxidase activity in Pittosporum leaves on the illumination level was studied. Adaptive reactions manifested in changes of peroxidase fractional composition in the leaves of the plants grown in different conditions. The obtained results on the activation and inactivation of the enzymatic activity of free and cell wall-associated peroxidase are interesting for using as an additional diagnostic indicator of stress degree for the plants of the interiors. It was established that adaptive changes in experimental plants were determined by the origin of species and their ecological and biological features.

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Differing mechanisms of cold-induced changes in capillary supply in m. tibialis anterior of rats and hamsters

Journal of Experimental Biology ◽

10.1242/jeb.205.6.829 ◽

2002 ◽

Vol 205 (6) ◽

pp. 829-840 ◽

Cited By ~ 2

Author(s):

Durmus Deveci ◽

Stuart Egginton

Keyword(s):

Skeletal Muscle ◽

Cold Acclimation ◽

Oxygen Diffusion ◽

Tibialis Anterior ◽

Capillary Density ◽

Disuse Atrophy ◽

Diffusion Distance ◽

Capillary Supply ◽

Fibre Size ◽

Anatomical Adaptations

SUMMARY The physiological, metabolic and anatomical adaptations of skeletal muscle to chronic cold exposure were investigated in Wistar rats (Rattus norvegicus), a species that defends core temperature, and Syrian hamsters (Mesocricetus auratus), which may adopt a lower set point under unfavourable conditions. Animals were exposed to a simulated onset of winter in an environmental chamber, progressively shortening photoperiod and reducing temperature from 12 h:12 h L:D and 22°C to 1 h:23 h L:D and 5°C over 4 weeks. The animals were left at 4°C for a further 4 weeks to complete the process of cold-acclimation. M. tibialis anterior from control (euthermic) and cold-acclimated animals of similar mass showed a significant hyperactivity-induced hypertrophy in the rat, but a small disuse atrophy in the hamster. Little evidence was found for interconversion among fibre types in skeletal muscle on cold-acclimation, and only modest differences were seen in activity of oxidative or glycolytic enzymes in either species. However, adjustments in Type II fibre size paralleled the muscle hypertrophy in rat and atrophy in hamster. Cold-induced angiogenesis was present in the rat, averaging a 28 % increase in capillary-to-fibre ratio (C:F) but, as this was balanced by fibre hypertrophy across the whole muscle, there was no change in capillary density (CD). In contrast, the C:F was similar in both groups of hamsters, whereas CD rose by 33 % in line with fibre atrophy. Within distinct regions of the m. tibialis anterior, there was a correlation between angiogenesis and fibre size in rats, in which oxygen diffusion distance increased, but not in hamsters, in which there was a reduced oxygen diffusion distance. Consequently, the change in C:F was greatest (39 %) in the glycolytic cortex region of the m. tibialis anterior in rats. We conclude that non-hibernator and hibernator rodents improve peripheral oxygen transport following cold-acclimation by different mechanisms. In rats, an increase in fibre girth was accompanied by a true angiogenesis, while the improved apparent capillary supply in hamsters was due to smaller fibre diameters. These responses are consistent with the strategies of resisting and accommodating, respectively, an annual fall in environmental temperature.

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The Anatomy of the Infra-red Sense Organ in the Facial Pit of Pit Vipers

Journal of Cell Science ◽

10.1242/jcs.s3-98.42.219 ◽

1957 ◽

Vol s3-98 (42) ◽

pp. 219-234

Author(s):

THEODORE H. BULLOCK ◽

WADE FOX

Keyword(s):

Sense Organ ◽

Single Layer ◽

Visible Spectrum ◽

Nerve Endings ◽

Size Spectrum ◽

Broad Absorption ◽

Fibre Size ◽

Infra Red ◽

Anatomical Adaptations ◽

Sensory Endings

1. The histological composition of the sensory membrane in the facial pit of rattle-snakes (Crotalus spp.), the disposition of the nerve-trunks entering it, the fibre-size spectrum of the nerves, and the form of the sensory endings are described. 2. Between the two layers of extremely attenuated epidermis the principal constituent of the membrane is a single layer of specialized parenchyma cells with osmiophil, reticular cytoplasm. These are not regarded as sense cells but they react strongly and locally to degeneration of nerve-endings. 3. The axons enter through numerous trunks from three branches of the trigeminal nerve, from all sides of the membrane, providing a dense innervation. They lose their myelin, taper to about 1µ, then expand into flattened palmate structures which bear many branched processes terminating freely over an average area of about 1,500µ2, overlapping only slightly with adjacent units but leaving virtually no area unsupplied. This means there are from 500 to 1,500 axons ending per mm2, an estimate which agrees with the nerve-counts. No other form of ending was found. 4. The mode of the fibre-size spectrum lies in the region 5-7µ, diameter. 5. A transmission spectrum of the fresh membrane shows broad absorption peaks at 3 and 6µ and about 50% transmitted in other regions out to 16µ. The visible spectrum is at least 50% transmitted and probably much is lost by reflection. Strong absorption takes place at wavelengths shorter than 490µ 6. The anatomical adaptations of the sense organ are discussed, especially the concentration of warm receptor fibres, the thinness of the membrane, the extremely superficial position of the nerve-endings--all increasing sensitivity to caloric flux. The overhanging margins of the pit and the richness of supply are believed to permit directionality of reception. 7. It is suggested that the palmate form of the ending has a significance in permitting several independent local sub-threshold activity generators to coexist in the processes and in pooling their coincident, electrotonically spread potentials to influence the initiation of spikes which may take place at the junction of axon and palm.

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Feathers and flight

Essential Ornithology ◽

10.1093/oso/9780198804741.003.0002 ◽

2020 ◽

pp. 21-47

Author(s):

Graham Scott

Keyword(s):

Collision Avoidance ◽

Wind Farm ◽

Bird Species ◽

Collision Risk ◽

Basic Physics ◽

Range Of Functions ◽

Anatomical Adaptations ◽

The Many

This chapter covers two themes: feathers and flight. It takes a close look at the many aspects of feathers—their evolution, structure, growth, maintenance, and their replacement through moult. The broad range of functions of feathers in display (including how different pigmentations arise), for insulation, and in flight are considered. Moult strategies are compared and discussed. The second part of the chapter describes the anatomical adaptations of birds to flight, and the process of flight itself. The basic physics, physiology and metabolism, and energetics of flight are covered in some detail. A review of studies on the neurological control of collision avoidance by flying birds and the implications in relation to wind-farm collision risk is given. The chapter ends with a discussion on the evolution of flight and subsequent flightlessness of some bird species.

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Multiple Matings and Sperm Competition

Reproductive Biology ◽

10.1093/oso/9780190688554.003.0012 ◽

2020 ◽

pp. 332-363

Author(s):

Carola Becker ◽

Raymond T. Bauer

Keyword(s):

Genetic Diversity ◽

Sperm Competition ◽

Mate Guarding ◽

Sperm Storage ◽

Internal Fertilization ◽

Multiple Matings ◽

Storage Organs ◽

Anatomical Adaptations ◽

Multi Level ◽

Molecular Aspects

In polyandrous mating systems, females mate multiple times and males have evolved adaptations for sperm competition which increase the number and fitness of their offspring. Mate guarding is a widespread monopolization strategy in groups where female receptivity is temporally restricted and often associated with the molt. Precopulatory guarding occurs in branchipods, copepods, peracarids and decapods. Postcopulatory guarding is notable in numerous brachyurans with males protecting females until her exoskeleton has hardened. During copulation, male success in fertilization depends on an effective sperm transfer mechanism, the precise placement of ejaculates closest to where female gametes are fertilized. Male copulatory systems are highly diverse and strongly adapted to these tasks, especially the structures that interact with the female genital ducts. The elaborate tips of brachyuran gonopods are supposed to act in the displacement, possibly even in the removal of rival sperm masses; however, sperm removal is only evident in crayfish: males eat spermatophores previously deposited by other males. During copulation of several crustacean groups, males transfer secretions that harden and form a sealant. These sperm plugs, plaques and gel layers may protect their own sperm, prevent remating or seal off rival sperm from the site of fertilization. Several groups of isopods and decapods have internal insemination, elaborate sperm storage organs and some exhibit internal fertilization. The intensity of sperm competition increases with the latency between the processes of insemination and fertilization. This chapter gives on overview on mate guarding, male sealants and the anatomical adaptations to sperm competition in crustaceans. We also briefly discuss the consequences of multiple matings for the genetic diversity of broods, i.e., single vs. multiple paternities. There is still a lack of data for many crustacean groups. Moreover, it is often hard to assess how successful a male strategy to ensure paternity actually is as many studies focus on either the behavioral, anatomical, or molecular aspects, while comprehensive multi-level studies on crustacean sperm competition are virtually absent from the literature.

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Anatomical adaptations in species of Poaceae growing in Al-Hair region of Riyadh, Saudi Arabia

African Journal of Plant Science ◽

10.5897/ajps2019.1809 ◽

2019 ◽

Vol 13 (7) ◽

pp. 201-208

Author(s):

A. Banan Shamah ◽

A. Al-Watban Ahlam ◽

R. Doaigey Abdullah ◽

A. Alsahli Abdulaziz ◽

El-Zaidy Mohamed

Keyword(s):

Saudi Arabia ◽

Anatomical Adaptations

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