Search results for "differentiation"

Polyamines and ripening of photoreceptor outer segments in chicken embryos.

1995

Abstract Polyamines and their related monoacetyl derivatives were studied in rod outer segment (ROS) and cone outer segment (COS) of photoreceptor cells from chick embryo retina during eye development (7th–18th days). Putrescine was found to be necessary, in the second phase of retinogenesis, to sustain both ROS and COS differentiation and, after acetylation, γ-aminobutyric acid synthesis. On the other hand, spermidine and even more spermine intervene in the third phase of development when photoreceptors mature. Moreover, the presence of N1-acetylspermidine already at the 7th day indicates that in the outer segment of photoreceptor cells too, as in the whole retina, putrescine synthesis com…

Stepping up to genome scan allows stock differentiation in the worldwide distributed blue shark Prionace glauca

2023

The blue shark Prionace glauca is a top predator with one of the widest geographic distributions of any shark species, yet classified as critically endangered in the Mediterranean Sea, and Near Threatened globally. Previous genetic studies did not reject the null hypothesis of a single global population across the worldwide species range. Blue shark situation was proposed as a possible archetype of the ‘grey zone of population differentiation’, coined to designate cases where population structure may be too recent or too faint to be detected using a limited set of markers. Here, blue shark samples collected throughout its global range were sequenced using a specific ddRAD method (DArTseq; G…

Variation of olivine composition in the volcanic rocks in the Songliao basin, NE China: lithosphere control on the origin of the K-rich intraplate ma…

2016

Abstract Lithospheric thickness and the heterogeneity of the mantle lithosphere are two major parameters that play a role in determining the final composition of the mafic melts and their minerals. The Songliao basin in northeast China represents an ideal natural laboratory to study the effect of these two parameters on early Pliocene to Holocene K-rich mafic lavas (K2O > 4 wt.%; K2O/Na2O > 1). A series of Cenozoic volcanic edifices (Erkeshan, Wudalianchi, Keluo and Xiaogulihe) are tentatively divided into three groups (Group 1 — thin, Group 2 — middle, and Group 3 — thick) according to the lithosphere thickness. They are located in the northern region of the Songliao basin extending in a n…

The oocyte derived growth factors, GDF9 and GDF9B, and their biological activities in 'in vitro' cell models

2007

Wharton’s jelly mesenchymal stem cells differentiation into hepatocyte-like cells: functional characterization and expression of immunomodulatory mol…

2015

Mesenchymal stem cells derived from Wharton’s jelly (WJ-MSCs) recently emerged as promising tools for cellular therapy due to their ability to differentiate into diverse cell types and their immunomodulatory features. Little is known on the expression of immunomodulatory molecules in mature cells differentiated from WJ-MSCs, therefore we aimed to characterize the extent of maintenance of the naive traits of these cells also in a highly specialized differentiated counterpart. WJ-MSCs were differentiated into hepatocyte-like cells (HLCs) with a four weeks protocol. RT-PCR, flow cytometry, IHC and ICC were performed to assess expression of key markers in both undifferentiated and differentiate…

Divergent parasite infections in sympatric cichlid species in Lake Victoria

2018

Parasitism has been proposed as a factor in host speciation, as an agent affecting coexistence of host species in species‐rich communities and as a driver of post‐speciation diversification. Young adaptive radiations of closely related host species of varying ecological and genomic differentiation provide interesting opportunities to explore interactions between patterns of parasitism, divergence and coexistence of sympatric host species. Here, we explored patterns in ectoparasitism in a community of 16 fully sympatric cichlid species at Makobe Island in Lake Victoria, a model system of vertebrate adaptive radiation. We asked whether host niche, host abundance or host genetic differentiatio…

Cell differentiation markers in human umbilical cord; an immunohistochemical study

2011

The full-term human umbilical cord is made of three blood vessels (two arteries and a vein) surrounded by the Wharton’s jelly, a soft connective tissue made of few mesenchymal stromal cells and an abundant extracellular matrix. Both endothelial and Wharton’s jelly cells are versatile in their differentiation potential; they have shown to be able to differentiate into several cell lineages. Since the differentiation potential of these cells is very wide, we thought it could be interesting to investigate the expression of several cell differentiation markers in the different regions of human umbilical cord. Immunohistochemistry showed the expression of E-cadherin and cytokeratins in the amnio…

Hybridization, developmental stability, and functionality of morphological traits in the ground beetle Carabus solieri (Coleoptera, Carabidae).

2006

Correspondance.: stephane.garnier@u-bourgogne.fr; International audience; The assessment of developmental stability in hybrids can provide valuable information in the study of species formation because it allows an evaluation of the degree of incompatibility of genetic systems that control developmental processes. The present study assessed the impact of two hybridization events, assumed to have occurred at different times, on developmental instability in the ground beetle Carabus solieri . Developmental instability was estimated in 678 individuals from 27 populations from the fluctuating asymmetry (FA) levels of four morphological traits: the tibia length of middle and hind legs, which are…

Izglītības iestādes vadības politika diferencēta mācību procesa nodrošināšanā vispārējā pamatizglītības posmā

2022

Pētījuma “Izglītības iestādes vadības politika diferencēta mācību procesa nodrošināšanā vispārējā pamatizglītības posmā” mērķis ir pētīt principus un organizatoriskos darbību soļus, kuru ievērošana Latvijas Republiku vispārējo pamatizglītības iestāžu vadību komandām ļauj nodrošināt mācību procesa diferenciāciju. Mācību procesa diferenciācija ir izglītojamo individuālo vajadzību ņemšana vērā, atbilstoši viņu vajadzībām (gatavība, intereses, mācību profils) pielāgojot mācību saturu, procesu, produktu jeb rezultātu, kā arī mācību vidi. To dara izglītības iestādes vadības komanda – organizēta cilvēku grupa, kura pārrauga un vada visus izglītības iestādē notiekošos procesus. Veiksmīgai mācību pr…

Networks of manufacturers and retailers

2011

We study the endogenous formation of networks between manufacturers of differentiated goods and multi-product retailers who interact in a successive duopoly. Joint consent is needed to establish and/or maintain a costly link between a manufacturer and a retailer. We find that only three distribution networks are stable for particular values of the degree of product differentiation and link costs: (i) the non-exclusive distribution & non-exclusive dealing network in which both retailers distribute both products is stable for intermediate degree of product differentiation and small link costs; (ii) the exclusive distribution & exclusive dealing network in which each retailer distributes a dif…