Search results for "Ontogeny"

Spatial and temporal dynamics of innervation during the development of fetal human pancreas.

2008

The delineation of pancreatic nerve innervations during fetal life may contribute to our understanding of pancreatic pain modalities after birth. The aim of this study was to characterize the spatial and temporal distribution of nerve structures in the human pancreas throughout gestation. Computer-based image morphometry with piecewise polynomial interpolation analysis was performed to quantify nervous structures in the head, body and tail of the pancreas. Nerve structures were detected by automatic immunostaining techniques using a polyclonal antibody against two S-100 proteins that reacts strongly with human S100A and B that are detected in Schwann cells. Immunoreactivity was found in the…

Effects of the Shiitake Mushroom on Ontogenesis and Reproduction of the Social Vole Microtus socialis

2001

Ontogenetic and phylogenetic diversification of the hooded staminode in Marantaceae

2010

The flowers of Marantaceae are known for their unique pollination mechanism mediated by an explosive style movement. The mechanism is based on the highly modified elements of the inner androecial whorl, i.e., the single half-fertile anther and the fleshy and hooded staminodes. We investigated 67 species across 24 genera to elucidate which parts of the hooded staminode are shared by all species, thus likely under strong selection pressure, and which are allowed to vary. We treated hooded staminodes as character syndromes and grouped them based on gross similarities. We identified characters underlying the similarity and investigated their diversity and developmental pathways. All hooded stam…

Combining ontogenetic and evolutionary scales of morphological disparity: a study of early Jurassic ammonites

2007

SUMMARY Two major research themes in Evolutionary Developmental Biology and in Paleobiology, respectively, have each become central for the analysis and interpretation of morphological changes in evolution: the study of ontogeny/ phylogeny connections, mainly within the widespread and controversial framework of heterochrony; and the study of morphological disparity, the morphological signal of biodiversity, describing secular changes in morphospace occupation during the history of any given clade. Although enriching in their respective fields, these two themes have remained rather isolated to date, despite the potential value of integrating them as some recent studies begin to suggest. Here…

Breaking the temperature-size rule: Thermal effects on growth, development and fecundity of a crustacean from temporary waters

2013

The temperature-size rule (TSR) is a well-established phenomenon to describe the growth response of ectotherms to temperature by which individuals maintained at low temperatures grow more slowly, but attain a larger size upon maturity. Although there are adaptive and non-adaptive theories about the plasticity of body size in response to temperature, these cannot be applied to all ectotherms, and little is known about the changes in growth and development rates through ontogeny. The ostracod species Heterocypris bosniaca, an inhabitant of freshwater temporary ponds, was used to examine the growth and development rates of its nine growth stages and female fecundity at four different temperatu…

Testing the ontogenetic base for the transient model of inflorescence development

2013

† Backgrounds and Aims: Current research in plant science has concentrated on revealing ontogenetic processes of key attributes in plant evolution. One recently discussed model is the ‘transient model’ successful in explaining some types of inflorescence architectures based on two main principles: the decline of the so called ‘vegetativeness’ (veg) factor and the transient nature of apical meristems in developing inflorescences. This study examines whether both principles find a concrete ontogenetic correlate in inflorescence development. † Methods: To test the ontogenetic base of veg decline and the transient character of apical meristems the ontogeny of meristematic size in developing inf…

Digestive Enzymes in Larvae and Juveniles of Farmed Sharpsnout Seabream (Diplodus puntazzo) (Cetti, 1777)

2011

The ontogenetic development and pattern of main digestive enzyme activities (proteases, carbohydrases and lipases) were investigated in farmed sharpsnout seabream Diplodus puntazzo larvae and juveniles, during the passage from the larval stage to adult (from 21 to 277 days after hatching - DAH). Larvae showed exponential growth, thus confirming that Rotifers and Artemia nauplii are suitable preys for early feeding of D. puntazzo larvae. Pepsin activity was low in the larvae, but it increased afterwards in relation with stomach development. In juveniles, levels of specific activity of trypsin, chymotrypsin and elastase were lower compared to that recorded in larvae. A decrease in the activit…

ANP Ontogeny in rat developing in the lateral choroid plexus.

2008

An immunohistochemical study was carried out to verify whether ANP is present in the lateral plexus in adult and embryos rats. The results evidenced the ANP presence in ependymal cells of the plexus in adult rat and also at 16° day of foetal life suggesting the imnportant role of ANP in the development and maturation of brain.

Atrial Natriuretic Peptide presence in parotid gland of human fetus at 13th week of development and in adult man

2013

Our immunohistochemical study shows that atrial natriuretic peptide (ANP) is present in both human fetal and adult parotid gland. In the fetuses ANP is localized in cell clusters, while in adult parotid gland, the ANP is seen only in the wall of intra- and extralobular ducts. The results suggest that ANP might play a role in the differentiation of the parotid gland similarly as in brain and that during fetal growth ANP may play a role in the regulating the secretion of primitive salivary fluid, even if acini are still not developed. (Folia Histochemica et Cytobiologica 2013, Vol. 51, No. 1, 55-58)

Quantification de révolution morphologique du crâne des Hominidés et hétérochronies

1998

Abstract Comparisons of adult skulls of various species of great apes, fossil hominids and modern humans in the sagittal, Francfort and ortho-sagittal planes reveal a series of three separate organisation plans: ‘Great Ape’, ‘Australopithecine’ and ‘Homo’, the latter including primitive men ( Homo ergaster-erectus-neandertalensis ) and modern humans ( Homo sapiens ). Morphological changes between these plans are quantified for the first time here by vector fields. This study confirms the existence of cranio-facial contraction, which occurs as a series of leaps. The juvenile morphology of the great ape skull is broadly preserved in adult Homo sapiens, suggesting that numerous heterochronies …