We investigated the acclimation of seedlings of three tropical rain forest sub-canopy Garcinia species (G. xanthochymus, G. cowa, and G. bracteata) after transfer from 4.5 (LI) to 40 % (HI) sunlight and 12.5 (MI) sunlight to HI (LH1 and LH2 denoting transfer from LI to HI and MI to HI transfer, respectively). The changes of chlorophyll (Chl) fluorescence, net photosynthetic rate (PN), dark respiration rate (RD), Chl content per unit area (Chlarea), leaf mass per unit area (LMA), and seedling mortality were monitored over two months after transfer. These parameters together with leaf anatomy of transferred and control seedlings (kept in LI, MI, and HI) were also examined after two months. No seedlings died during the two months. Fv/Fm, PN, and Chlarea of the transferred seedlings decreased in the first 3 to 12 d. LH1 leaves showed larger reduction in Fv/Fm (>23 % vs. <16 %) and slower recovery of Fv/Fm than LH2 leaves. PN started to recover after about one week of I transfer and approached higher values in all G. cowa seedlings and G. xanthochymus LH1 seedlings than those before the transfer. However, PN of G. bracteata seedlings approached the values before transfer. The final PN values in leaves of transferred G. xanthochymus and G. cowa seedlings approached that of leaves kept in HI, while the final PN values of transferred leaves of G. bracteata were significantly lower than that of leaves grown under HI (p<0.05). RD of G. xanthochymus LH1 seedlings and all G. cowa seedlings increased and approached the value of the seedlings in HI. The final Chlarea of both G. xanthochymus and G. cowa approached the values before transfer, but that of G. bracteata did not recover to the level before transfer. The final Chlarea of all transferred seedlings was not significantly different from that of seedlings in HI except that G. cowa LH1 seedlings had higher Chlarea than that in HI. LMA decreased within 2 d and then increased continuously until about 30 d and approached the value under HI. Spongy/palisade mesophyll ratio decreased after transfer because of the increase in palisade thickness. Leaf thickness did not change, so LMA increase of transferred seedlings was mainly due to the increase of leaf density. Thus the mature leaves under LI and MI of G. xanthochymus and G. cowa are able to acclimate to HI by leaf physiological and anatomical adjustment, while G. bracteata had limited ability to acclimate to HI. and X. R. Guo, K. F. Cao, Z. F. Xu.
The skin histology from the Danubian spined loach Cobitis elongatoides disputes the notion that the spawning marks (lighter spots on the body sides of the females) are the result of physical damage to the epidermis by a male during spawning. Physiological changes that induce a specific local decrease in lateral pigmentation in some individuals appear to be a more likely source.
The epidermis of the amphibious mudskipper fish, Boleophthalmus pectinirostris, consists of three layers: the outermost layer, middle layer and stratum germinativum. The outermost layer consists of polygonal cells or rather flattened cells arranged in one to eight layers. In between these cells, round small cells and mucous cells are present. The round small cells are ovoid to round with an inclusion of fine granules, which are weakly positive to acid chemical reaction. The mucous cells are predominantly acid mucopolysaccharide in nature. The middle layer consists of 1 to 50 layers of small or voluminous cells swollen by epidermal cells. Owing to various sizes and layers of the swollen cell, the middle layer shows a web-like structure. The stratum germinativum consists of a single layer of cuboidal cells, or more or less columnar cells. A dermal bulge is located at each apical area of the epidermis of the body regions, but does not exist in all the fins or in the sucking disc. In the epidermis of the body regions, the dermal bulges are sparsely occupied by dermal tissue and have dermal capillaries just beneath the stratum germinativum. The value of the diffusion distance is the lowest in the top of the head (mean 5.5 μm) and the highest in the ventral region (mean 44.3 μm).
The glycophenotyping of mammalian cells with plant lectins maps aspects of the glycomic profile and disease-associated alterations. A salient step toward delineating their functional dimension is the detection of endogenous lectins. They can translate sugar-encoded changes into cellular responses. Among them, the members of the lectin family of galectins are emerging regulators of cell adhesion, migration and proliferation. Focusing on galectins-1, -3 and -7, we addressed the issue whether their expression is regulated during wound healing in porcine skin as model. A conspicuous upregulation is detected for galectin-1 in the dermis and a neoexpression in the epidermis, where an increased level of galectin-7 was also found. Applying biotinylated tissue lectins as probes, the signal intensities for accessible binding sites decreased, intimating an interaction of the cell lectin with reactive sites. In contrast, galectin-3 parameters remained rather constant. Of note, epidermal cells in culture also showed an increase in expression/presence of galectin-1, measured on the levels of mRNA and protein, in this case by Western blotting and quantitative immunocytochemistry. Used as matrix, galectin-1 conferred resistance to trypsin treatment to attached human keratinocytes and reduced migration into scratch-wound areas in vitro. This report thus presents new information on endogenous lectins in wound healing and differential regulation among the three tested cases., J. Klíma ... [et al.]., and Obsahuje seznam literatury
A new species of trichosomoidid nematode, Huffmanela paronai sp. n., is established on the basis of its egg morphology and biological characters. The dark-shcllcd, cmbryonatcd eggs of this histozoic parasite occur in masses in the epidermis of the swordfish Xiphias gladius L. (Xiphiidae, Perciformes) from the Ligurian Sea in northern Italy. The eggs are concentrated in groups appearing as black spots in the skin of the fish host, being distributed mainly on the lower part of its body (lower jaw, gill covers, pectoral, anal and caudal fins, lower half of body). The parasite’s eggs are characterised mainly by their shape and markedly small size (48-51 x 21-24 pm), an aspinose surface, relatively small polar plugs, and thick egg wall (3 pm). This is the first Huffmanela species reported from fish in Europe.
A comparative study of mitotic activities and haemolymph ecdysteroid levels was performed in the phasmid Clitumnus extradentatus. Temporal correlation was found between increases in mitotic frequency in mandibular and general epidermis, and variations of ecdysteroid levels in the haemolymph of the insects. Whereas, mitotic waves occurring in the fat body cells or in the basal cells of the midgut did not appear to be strictly correlated with these hormonal variations. During the fourth larval instar of this phasma; an accurate study of mitotic figures, monitored from histological sections, indicated a time-lag in their stimulation according to the studied area, with a peak on day 2 in the mandible tips, on day 5 in the mandible bases and on day 7 in the head capsule, thorax and abdomen epidermis: namely a five-day delay with respect to the 12 days of the fourth instar. Simultaneously, the evolution of ecdysteroid levels in the haemolymph showed three increases of different importance. Each hormonal increase occurred 24 h before the triggering of each increase in the mitotic activity, whereas a fourth and very high peak, occurring on day 8, corresponded to the sudden fall in the number of epidermal mitoses.