scholarly journals Foliar colleters in Macrocarpaea obtusifolia (Gentianaceae): anatomy, ontogeny, and secretion

Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Valdnéa Casagrande Dalvi ◽  
Lucas Siqueira Cardinelli ◽  
Renata Maria Strozi Alves Meira ◽  
Aristéa Alves Azevedo
Keyword(s):  
Chemical Nature ◽  
Developmental Stages ◽  
Structure And Function ◽  
Histochemical Analysis ◽  
Secretory Structures ◽  
Standard Type ◽  
Vegetative Organs ◽  
New Information ◽  
And Function ◽  
First Time

Colleters are secretory structures located in reproductive and (or) vegetative organs of many eudicots. In Gentianaceae Juss., the presence of foliar colleters has been neglected, and anatomical and histochemical studies are scarce. The objectives of this study were to investigate the anatomy, ontogeny, and chemical nature of the secretion found in Macrocarpaea obtusifolia (Griseb.) Gilg colleters to establish a relationship between their structure and function and check whether these structures are similar to those described for other genera of the Gentianaceae and other families of the Gentianales. Samples of leaves at different developmental stages were collected and processed for anatomical and histochemical analysis using light microscopy and scanning electron microscopy. Colleters in M. obtusifolia have a protodermal origin, are of standard type, and are not vascularized. Young colleters are translucent and produce an abundant amount of sticky secretion. Later, they turn yellowish with a blackened region at the apex of the head, and the secretion, composed of polysaccharides and proteins, becomes less abundant and brownish. During senescence, the process begins with complete degradation and cell collapse of the secretory portion. The colleters of the standard type in M. obtusifolia have been observed for the first time in the Gentianaceae and represent additional evidence that reinforces how common this type of colleter is in the Gentianales. Such results provide new information on the anatomy, ontogeny, histochemistry, and colleter types of Gentianaceae.

Strategies for Oral Delivery of Metal-Saturated Lactoferrin

2019 ◽  
Vol 20 (11) ◽  
pp. 1046-1051 ◽  
Author(s):  
Przemysław Gajda-Morszewski ◽  
Klaudyna Śpiewak-Wojtyła ◽  
Maria Oszajca ◽  
Małgorzata Brindell
Keyword(s):  
Biological Activity ◽  
Oral Delivery ◽  
Therapeutic Potential ◽  
Structure And Function ◽  
The Difference ◽  
And Function ◽  
First Time

Lactoferrin was isolated and purified for the first time over 50-years ago. Since then, extensive studies on the structure and function of this protein have been performed and the research is still being continued. In this mini-review we focus on presenting recent scientific efforts towards the elucidation of the role and therapeutic potential of lactoferrin saturated with iron(III) or manganese(III) ions. The difference in biological activity of metal-saturated lactoferrin vs. the unmetalated one is emphasized. The strategies for oral delivery of lactoferrin, are also reviewed, with particular attention to the metalated protein.

scholarly journals Influence of High Pressure on the Dimerization of ToxR, a Protein Involved in Bacterial Signal Transduction

2008 ◽  
Vol 74 (24) ◽  
pp. 7821-7823 ◽  
Author(s):  
Kai Linke ◽  
Nagarajan Periasamy ◽  
Matthias Ehrmann ◽  
Roland Winter ◽  
Rudi F. Vogel
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
High Pressure ◽  
Structure And Function ◽  
Transmembrane Segments ◽  
Bacterial Signal Transduction ◽  
Reporter Strains ◽  
And Function ◽  
First Time

ABSTRACT High hydrostatic pressure (HHP) is suggested to influence the structure and function of membranes and/or integrated proteins. We demonstrate for the first time HHP-induced dimer dissociation of membrane proteins in vivo with Vibrio cholerae ToxR variants in Escherichia coli reporter strains carrying ctx::lacZ fusions. Dimerization ceased at 20 to 50 MPa depending on the nature of the transmembrane segments rather than on changes in the ToxR lipid bilayer environment.

scholarly journals Plant Histone HTB (H2B) Variants in Regulating Chromatin Structure and Function

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1435
Author(s):  
Janardan Khadka ◽  
Anat Pesok ◽  
Gideon Grafi
Keyword(s):  
Arabidopsis Thaliana ◽  
Chromatin Structure ◽  
Developmental Stages ◽  
Histone Variants ◽  
Structure And Function ◽  
Core Histone ◽  
Histone H2b ◽  
Histone Proteins ◽  
Genes Encoding ◽  
And Function

Besides chemical modification of histone proteins, chromatin dynamics can be modulated by histone variants. Most organisms possess multiple genes encoding for core histone proteins, which are highly similar in amino acid sequence. The Arabidopsis thaliana genome contains 11 genes encoding for histone H2B (HTBs), 13 for H2A (HTAs), 15 for H3 (HTRs), and 8 genes encoding for histone H4 (HFOs). The finding that histone variants may be expressed in specific tissues and/or during specific developmental stages, often displaying specific nuclear localization and involvement in specific nuclear processes suggests that histone variants have evolved to carry out specific functions in regulating chromatin structure and function and might be important for better understanding of growth and development and particularly the response to stress. In this review, we will elaborate on a group of core histone proteins in Arabidopsis, namely histone H2B, summarize existing data, and illuminate the potential function of H2B variants in regulating chromatin structure and function in Arabidopsis thaliana.

scholarly journals Crab scars reveal survival advantage of left-handed snails

2006 ◽  
Vol 2 (3) ◽  
pp. 439-442 ◽  
Author(s):  
Gregory P Dietl ◽  
Jonathan R Hendricks
Keyword(s):  
Social Interactions ◽  
Structure And Function ◽  
Snail Species ◽  
Left Handedness ◽  
Left Handed ◽  
Selection Processes ◽  
Living Organisms ◽  
And Function ◽  
First Time ◽  
Crab Predation

Biological asymmetries are important elements of the structure and function of many living organisms. Using the Plio–Pleistocene fossil record of crab predation on morphologically similar pairs of right- and left-handed snail species, we show here for the first time, contrary to traditional wisdom, that rare left-handed coiling promotes survival from attacks by right-handed crabs. This frequency-dependent result influences the balance of selection processes that maintain left-handedness at the species level and parallels some social interactions in human cultures, such as sports that involve dual contests between opponents of opposite handedness.

Structure and Function of the Normal Testis and Epididymis

1989 ◽  
Vol 8 (3) ◽  
pp. 457-471 ◽  
Author(s):  
Rupert P. Amann
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Developmental Stages ◽  
Structure And Function ◽  
Germinal Epithelium ◽  
Sperm Production ◽  
Human Male ◽  
Conventional Animal ◽  
And Function ◽  
Hormonal Interactions

The structure and function of the testis and epididymis are described, emphasizing the general similarities and specific differences between various species and humans. Current concepts of spermatogenesis are reviewed and the developmental stages of the germinal epithelium are discussed, as well as the complex hormonal interactions that take place. It is crucial to recognize that the efficiency of sperm production and the epididymal reserves in the human are considerably lower than those of conventional animal models. Therefore, the human male is more susceptible to a decline in fertility caused by a specific decrement in spermatogenesis than is an animal model.

scholarly journals Comparative transcriptome analysis identifies genes associated with chlorophyll levels and reveals photosynthesis in green flesh of radish taproot

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252031
Author(s):  
Yuan-yuan Li ◽  
Min Han ◽  
Rui-hua Wang ◽  
Ming-gang Gao
Keyword(s):  
Carbon Fixation ◽  
Developmental Stages ◽  
Developmental Process ◽  
Calvin Cycle ◽  
Comparative Transcriptome ◽  
Chl A ◽  
New Information ◽  
Green Tissue ◽  
And Function ◽  
Chl Fluorescence

The flesh of the taproot of Raphanus sativus L. is rich in chlorophyll (Chl) throughout the developmental process, which is why the flesh is green. However, little is known about which genes are associated with Chl accumulation in this non-foliar, internal green tissue and whether the green flesh can perform photosynthesis. To determine these aspects, we measured the Chl content, examined Chl fluorescence, and carried out comparative transcriptome analyses of taproot flesh between green-fleshed “Cuishuai” and white-fleshed “Zhedachang” across five developmental stages. Numerous genes involved in the Chl metabolic pathway were identified. It was found that Chl accumulation in radish green flesh may be due to the low expression of Chl degradation genes and high expression of Chl biosynthesis genes, especially those associated with Part Ⅳ (from Protoporphyrin Ⅸ to Chl a). Bioinformatics analysis revealed that differentially expressed genes between “Cuishuai” and “Zhedachang” were significantly enriched in photosynthesis-related pathways, such as photosynthesis, antenna proteins, porphyrin and Chl metabolism, carbon fixation, and photorespiration. Twenty-five genes involved in the Calvin cycle were highly expressed in “Cuishuai”. These findings suggested that photosynthesis occurred in the radish green flesh, which was also supported by the results of Chl fluorescence. Our study provides transcriptome data on radish taproots and provides new information on the formation and function of radish green flesh.

Tomb Robberies at the End of the New Kingdom

2018 ◽  
Author(s):  
Valentina Gasperini
Keyword(s):  
British Museum ◽  
New Kingdom ◽  
Intermediate Period ◽  
Ancient Egyptian ◽  
New Information ◽  
New Interpretation ◽  
And Function ◽  
The 19Th Century ◽  
First Time ◽  
Egyptian History

At the end of the 19th century W.M.F. Petrie excavated a series of assemblages at the New Kingdom Fayum site of Gurob. These deposits, known in the Egyptological literature as 'Burnt Groups', were composed by several and varied materials (mainly Egyptian and imported pottery, faience, stone and wood vessels, jewellery), all deliberately burnt and buried in the harem palace area of the settlement. Since their discovery these deposits have been considered peculiar and unparalleled. Many scholars were challenged by them and different theories were formulated to explain these enigmatic 'Burnt Groups'. The materials excavated from these assemblages are now curated at several Museum collections across England: Ashmolean Museum, British Museum, Manchester Museum, and Petrie Museum. For the first time since their discovery, this book presents these materials all together. Gasperini has studied and visually analysed all the items. This research sheds new light on the chronology of deposition of these assemblages, additionally a new interpretation of their nature, primary deposition, and function is presented in the conclusive chapter. The current study also gives new information on the abandonment of the Gurob settlement and adds new social perspective on a crucial phase of the ancient Egyptian history: the transition between the late New Kingdom and the early Third Intermediate Period. Beside the traditional archaeological sources, literary evidence ('The Great Tomb Robberies Papyri') is taken into account to formulate a new theory on the deposition of these assemblages.

MORPHOLOGY, DISTRIBUTION, AND HISTOCHEMISTRY OF SECRETORY STRUCTURES IN VEGETATIVE ORGANS OF SANTOLINA LEUCANTHA BERTOL. (ASTERACEAE)

1999 ◽  
Vol 47 (4) ◽  
pp. 257-263 ◽  
Author(s):  
Anna Marta Pagni ◽  
Antonio Masini
Keyword(s):  
Glandular Trichomes ◽  
Secondary Compounds ◽  
Histochemical Analysis ◽  
Secretory Structures ◽  
Vegetative Organs ◽  
Secretory Ducts

In the vegetative organs of Santolina leucantha Bertol. (Anthemideae), two distinct types of secretory structures are present: Internal secretory ducts and external glandular trichomes. The ducts are variable in morphology and location, depending on the organ in which they are present. The trichomes, however, show the same structure everywhere. In the roots, there are also scattered cells rich in secretion that are distributed in the periphery of the cortical cylinder. The histochemical analysis of the secretion reveals the presence in all the vegetative organs of many important secondary compounds. Vegetative secretory structures are similar to those in the capitulum we have described in a previous paper.

Memoirs: On Ptychodera flava, Eschscholtz

1897 ◽  
Vol s2-40 (157) ◽  
pp. 165-184
Author(s):  
ARTHUR WILLEY
Keyword(s):  
Living Condition ◽  
Structure And Function ◽  
The Other ◽  
Detailed Structure ◽  
Pharyngeal Wall ◽  
Littoral Habitat ◽  
Collar Region ◽  
Ptychodera Flava ◽  
And Function ◽  
First Time

1. This is the first time that an Enteropneust with a free pharynx has been studied in the living condition. 2. The Ptychodera flava of Eschscholtz (char. emend. mihi) is rightly assigned by Spengel to his amended genus Ptychodera, as shown by the presence of the genital pleura, of external liver saccules, and by the length of the collar region. 3. P. flava belongs to Spengel's sub-genus Chlamydothorax, as shown by the ventral origin of the genital pleura, the diffuse gonads, and the free pharynx. 4. In the fact of the gill-slits being open directly to the exterior throughout their entire length, P. flava is more closely related to P. bahamensis than to any other described species. This is also indicated by the simple rows of paired liver saccules as opposed to the irregular multiple arrangement met with in P. erythræa. 5. The genus Ptychodera. (referring more especially to the sub-genus Chlamydothorax) probably represents an archaic type, as shown by the diffuse arrangement of the gonads, the free pharynx, and its littoral habitat; and it is probably not, as Spengel supposes it to be, phylogenetically younger than the other genera of Enteropneusta. 6. The gill-slits, branchial skeleton, and the temporary atrium formed by the apposition of the genital pleura in Ptychodera, offer a general homology to the corresponding structures in Amphioxus and the Ascidians, while presenting many differences in the details of their structure and relations. 7. Some of these differences are comparatively unimportant, and such as might well be expected to occur in distantly related forms with such totally different habits of existence, while others are to be accounted for by a wide interpretation of the principle of correlation between structure and function. 8. Many differences of detailed structure in the pharyngeal wall and its skeletal supports between the Enteropneusta and Amphioxus are to be correlated with the fact that, in the former, the tongue-bars are larger (often, as in P. flava, very much larger) than the primary bars, while in the latter the reverse condition obtains.

The Bakerian Lecture, 1972 - Insulin, its chemistry and biochemistry

1974 ◽  
Vol 186 (1084) ◽  
pp. 191-215 ◽  
Keyword(s):  
Amino Acid ◽  
Amino Acid Analysis ◽  
Structure And Function ◽  
Complete Understanding ◽  
Know How ◽  
New Information ◽  
History Of ◽  
And Function ◽  
Structure Of Proteins

It is fifty years, this year, since insulin was successfully used to treat patients suffering from diabetes. It is thirty years since A. C. Chibnall gave the Bakerian lecture on ‘Amino acid analysis and the structure of proteins’, (1942), including insulin, and ten years since F. G. Young gave the Croonian lecture on ‘Insulin and its action’ (1962). It is difficult not to feel that this is a particularly appropriate moment at which to discuss, once again, insulin, its chemistry and biochemistry, its structure and function. Chibnall did, of course, warn us in 1942 to beware of the ‘hypnotic power of numerology’. The most serious reason for discussing insulin today is not the existence of the recurring anniversaries (other dates are more important in the history of the study of insulin), but the fact that we still do not know how it works in living creatures. Very recently we have acquired a great wealth of new information about the actual arrangement in space of the atoms in insulin molecules in crystals. We can begin to answer many of the questions chemists and biochemists have been asking about the behaviour of insulin for years past. It seems useful to give here some of these answers in the hope that they may guide further experiments towards the complete understanding of the action of insulin that still eludes us.

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