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

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.


2019 ◽  
Vol 20 (11) ◽  
pp. 1046-1051 ◽  
Author(s):  
Przemysław Gajda-Morszewski ◽  
Klaudyna Śpiewak-Wojtyła ◽  
Maria Oszajca ◽  
Małgorzata Brindell

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.



2008 ◽  
Vol 74 (24) ◽  
pp. 7821-7823 ◽  
Author(s):  
Kai Linke ◽  
Nagarajan Periasamy ◽  
Matthias Ehrmann ◽  
Roland Winter ◽  
Rudi F. Vogel

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.



2013 ◽  
pp. 1-32 ◽  
Author(s):  
Leszek Konieczny ◽  
Irena Roterman-Konieczna ◽  
Paweł Spólnik


Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Valdnéa Casagrande Dalvi ◽  
Lucas Siqueira Cardinelli ◽  
Renata Maria Strozi Alves Meira ◽  
Aristéa Alves Azevedo

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.



Author(s):  
Alan Herbert ◽  
Alexander Rich


1897 ◽  
Vol s2-40 (157) ◽  
pp. 165-184
Author(s):  
ARTHUR WILLEY

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.



1998 ◽  
Vol 201 (21) ◽  
pp. 2913-2925 ◽  
Author(s):  
K B Døving ◽  
D Trotier

Many animals use their vomeronasal organs to gain direct and specific contact with chemical cues released by congeners and in biological fluids. These cues provide information about the physiological status of the emitter and facilitate or regulate social interactions such as sexual relationships. The present review gives a short description of the discovery of the vomeronasal organ and the pivotal findings of Jacobson. The distribution of the organ and its anatomy in some vertebrates are described. The mechanisms for stimulus entry and egress are discussed, and the findings that led to the appreciation of the vomeronasal organ in mammals as a main chemosensory organ for pheromones mediating reproductive status and inducing sexual behaviour are reported. The anatomical, biochemical and functional properties of the receptor neurones are described.



Author(s):  
John Parrington

This book draws on the latest research on the human brain to show how it differs strikingly from those of other animals in its structure and function at molecular and cellular level. It argues that this ‘shift’, enlarging the brain, giving it greater flexibility and enabling higher functions such as imagination, was driven by tool use, but especially by the development of one remarkable tool—language. The complex social interaction brought by language opened up the possibility of shared conceptual worlds, enriched with rhythmic sounds and images that could be drawn on cave walls. This transformation enabled modern humans to generate an exceptional human consciousness, a sense of self that arises as a product of our brain biology and the social interactions we experience. Linking early work by the Russian psychologist Lev Vygotsky to the findings of modern neuroscience, the book also explores how language, culture, and society mediate brain function, and what this view of the human mind may bring to our understanding and treatment of mental illness.



Antibodies ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 29 ◽  
Author(s):  
Lefranc ◽  
Lefranc

At the 10th Human Genome Mapping (HGM10) Workshop, in New Haven, for the first time, immunoglobulin (IG) or antibody and T cell receptor (TR) variable (V), diversity (D), joining (J), and constant (C) genes were officially recognized as ‘genes’, as were the conventional genes. Under these HGM auspices, IMGT®, the international ImMunoGeneTics information system® (http://www.imgt.org), was created in June 1989 at Montpellier (University of Montpellier and CNRS). The creation of IMGT® marked the birth of immunoinformatics, a new science, at the interface between immunogenetics and bioinformatics. The accuracy and the consistency between genes and alleles, sequences, and three-dimensional (3D) structures are based on the IMGT Scientific chart rules generated from the IMGT-ONTOLOGY axioms and concepts: IMGT standardized keywords (IDENTIFICATION), IMGT gene and allele nomenclature (CLASSIFICATION), IMGT standardized labels (DESCRIPTION), IMGT unique numbering and IMGT Collier de Perles (NUMEROTATION). These concepts provide IMGT® immunoinformatics insights for antibody V and C domain structure and function, used for the standardized description in IMGT® web resources, databases and tools, immune repertoires analysis, single cell and/or high-throughput sequencing (HTS, NGS), antibody humanization, and antibody engineering in relation with effector properties.



2008 ◽  
Vol 364 (1519) ◽  
pp. 881-894 ◽  
Author(s):  
V Llaurens ◽  
M Raymond ◽  
C Faurie

Since prehistoric times, left-handed individuals have been ubiquitous in human populations, exhibiting geographical frequency variations. Evolutionary explanations have been proposed for the persistence of the handedness polymorphism. Left-handedness could be favoured by negative frequency-dependent selection. Data have suggested that left-handedness, as the rare hand preference, could represent an important strategic advantage in fighting interactions. However, the fact that left-handedness occurs at a low frequency indicates that some evolutionary costs could be associated with left-handedness. Overall, the evolutionary dynamics of this polymorphism are not fully understood. Here, we review the abundant literature available regarding the possible mechanisms and consequences of left-handedness. We point out that hand preference is heritable, and report how hand preference is influenced by genetic, hormonal, developmental and cultural factors. We review the available information on potential fitness costs and benefits acting as selective forces on the proportion of left-handers. Thus, evolutionary perspectives on the persistence of this polymorphism in humans are gathered for the first time, highlighting the necessity for an assessment of fitness differences between right- and left-handers.



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