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Results for “Developmental stage”

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PubMed1992

Novel excision products of T cell receptor gamma gene rearrangements and developmental stage specificity implied by the frequency of nucleotide insertions at signal joints.

We have cloned circular DNA excised by T cell receptor (TcR) gamma 1, gamma 2 and gamma 3 gene rearrangements in fetal and adult mouse thymocytes. Circular DNA contained a signal joint reciprocal to the genomic V-J coding joint. Although signal joints without nucleotide insertions are common in immunoglobulin (Ig) and TcR gene rearrangements, the signal joint of gamma found in adult thymocytes contained non-germ-line element (N) insertions at high frequency, while no insertions were found in fetal thymocytes. Thus developmental stage specificity of TcR gamma gene rearrangements is faithfully reflected on the signal joint of excision products. In addition, examination of gamma gene excision products revealed circular DNA products of TcR gamma-alpha transrearrangements, but no evidence of V gamma gene replacement in a rearranged segment.

Age Factors↗

PubMed2002

Cell-to-cell movement of the PVX 12K, 8K, or coat proteins may depend on the host, leaf developmental stage, and the PVX 25K protein.

The requirements for intercellular movement of Potato virus X (PVX) 12K, 8K, and coat proteins (CP) differed in two Nicotiana spp. Plasmids containing the green fluorescent protein (GFP) gene fused to PVX 12K, 8K, or CP genes were bombarded to tobacco leaves. Protein movement was observed in N. benthamiana but not N. tabacum leaves. GFP:12K and GFP:8K moved cell-to-cell in 25K-expressing transgenic N. tabacum source but not sink leaves. In N. tabacum, GFP:12K and GFP:8K intercellular movement depends on the 25K and leaf developmental stage. Leaves were bombarded using two biolistic delivery methods and the results were similar indicating that movement of GFP:12K or GFP:8K is independent of the delivery system. Mutations in 12K, 8K, and CP genes within the PVX genome inhibited viral intercellular movement in both Nicotiana spp. Thus plasmodesmata gating is not an essential function of these proteins for virus cell-to-cell movement. These proteins likely provide additional activities for virus cell-to-cell movement.

Biolistics↗

PubMed1994

Identification and partial characterization of the proteases from different developmental stages of Schistocephalus solidus (Cestoda: Pseudophyllidae).

The proteolytic activities of extracts prepared from procercoids and plerocercoids as well as adults of the pseudophyllidean cestode Schistocephalus solidus were examined using several proteins and synthetic peptides as substrates. Whole bodies of procercoids and the isolated syncytial tegument of plerocercoids and adults prepared by freeze-thaw were studied. Extracts of procercoids contained a chymotrypsin-like proteinase exhibiting a molecular weight of 23,500 determined by gel filtration chromatography. The proteinase showed collagenolytic activity and had a pH optimum at 8. Such a proteinase was absent in plerocercoids and adults. In these developmental stages leucine aminopeptidases were detected in the isolated syncytial tegument having molecular weights of 93,500 (plerocercoids) and 89,000 (adults), respectively. The aminopeptidases in both stages displayed optimal activity at pH 8.5. The chymotrypsin-like proteinase of the procercoid is possibly necessary for the penetration of the host's intestinal wall, whereas the aminopeptidases of the plerocercoid and the adult of S. solidus may aid in parasite nutrition by degrading oligopeptides at the tegumental surface.

Aminopeptidases↗

PubMed2006

Variation in the holm oak leaf proteome at different plant developmental stages, between provenances and in response to drought stress.

Major proteins of the holm oak leaf proteome have been previously identified using a combination of 2-DE, MS analysis and BLAST similarity search (Jorge et al., Proteomics 2005, 5, 222-234). That study, conducted with field samples from mature trees, revealed the existence of a great variability in the 2-DE protein map, with qualitative as well as quantitative changes, both analytical and biological. A similar study has been carried out with 2-year-old seedlings to analyze and study: (i) changes in the 2-DE protein profile at different tree developmental stages; (ii) the 2-DE protein map variability between three different Spanish provenances; and (iii) variations in the 2-DE protein profile in response to drought stress. Although the protein profile of leaves from seedlings and mature trees was fairly similar, the biological variance found was lower in the former. In the present study, new proteins have been identified. At least four different protein spots differentiated Spanish provenances, two of them identified as an ATP synthase alpha chain, and a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase. Fourteen different protein spots were qualitatively variable between well-watered and drought-stressed seedlings, with some of them corresponding to enzymes of carbohydrate and protein metabolism. Data presented indicated the mobilization of storage proteins and carbohydrates, as well as photosynthesis inhibition under drought conditions.

Dehydration↗

PubMed1992

Developmental stages of the vomeronasal organ in the rat: a light and electron microscopic study.

This paper describes the development of the rat vomeronasal organ from the stage of anlage until adulthood. Groups of four rats were sacrificed daily from prenatal day 13 (E13) until birth; at days 2, 4, 7, 10, 14 and 16 after birth; weekly from day P21 to P42 plus an additional group of adults. The vomeronasal organs were processed for light microscopy, including alcian blue-PAS and NADH-diaphorase reactions, and also for electron microscopy. For summarizing our results we propose the following developmental stages: 1. Anlage (E13). 2. Early morphogenesis (E14-16). 3. Late morphogenesis (E17 to birth). 4. Initiation of secretory activity (First postnatal week). 5. Cytoarchitectural maturity (2nd postnatal week). 6. Complete maturity (From 3rd postnatal week onwards). Our results on the maturation of the histological structure and the histochemical reactions, indicate that there may be some functional activity at birth but the development of the organ still continues during the first three postnatal weeks to acquire its full functional capability.

Animals↗

PubMed1994

The impact of developmental stage, route of administration and the immune system on adenovirus-mediated gene transfer.

Important aspects of successful adenovirus gene transfer include the amount and persistence of gene expression, the ability to readminister virus and the localization of virus-directed gene expression to target organs. Our objective in this study was to use a single recombinant adenovirus bearing a quantifiable reporter gene [chloramphenicol acetyltransferase (CAT)] to establish the parameters which define the limits of adenovirus gene expression in a rat model. First, we determined how the route of virus administration affected the amount, duration and distribution of expression in different tissues and in rats of different developmental stages. All routes resulted in infection of all tissues tested. Surprisingly, the most efficient and widespread gene transfer was achieved by intracardiac muscle injection. The high levels of CAT protein that can be produced in a liver (< or = 1.7 mg) or a heart (< or = 196 micrograms) 5 days after infection suggest that the amount of gene product will not be a limitation in the use of adenovirus. Following peak activity at 5 days after infection, a gradual decline of CAT expression was observed in all tissues assayed; by 80 days neither CAT activity nor adenovirus DNA were detectable. In addition, adults could not be boosted by a second administration of virus, presumably due to the presence of high levels of neutralizing antibodies. The limited persistence of gene expression could be circumvented when virus was injected into neonates. Blocking T lymphocyte expansion by cyclosporine enhanced the persistence of CAT gene product over a 25-day period in heart and lung but not in liver compared with control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoviridae↗

PubMed2001

Analysis of 1202 orthopantograms to evaluate the potential of forensic age determination based on third molar developmental stages.

A total of 1202 orthopantograms of young dental patients were analyzed to assess the correlation of third molar root development with chronological age. The investigated patients were treated at a university dental clinic on an outpatient basis, included a variety of demographic characteristics (600 males and 602 females, 28% of other than central European background), and were 15-24 years old when the radiographs were obtained. Radiographs in which more than one third molar were either missing due to agenesia or extraction, or not evaluable because of deep destruction or marked tilting, were not included in the analysis. Our findings show that the growth patterns of third molars, based on seven defined stages of root development, did correlate with chronological age; age estimation when applied to a specific individual would involve a margin of error of +/- 2-4 years. There were no significant differences between the left and right jaw segments, but the stage of root development was generally more advanced in the upper than in the lower third molars. Root development was also more advanced among boys than among girls of the same age. There were no apparent differences in growth patterns based on national/ethnic background. While only 2.5% of 18-year-olds revealed fully developed third molars in all four quadrants, this percentage leaped to 38.4% among the 21-year-olds. To summarize, while the developmental stage of third molars is not per se a highly useful indicator of chronological age in juveniles and young adults, it is nevertheless a valuable supplementary parameter given the scarcity of other available age indicators.

Adolescent↗

PubMed1996

Salicylic acid-independent induction of pathogenesis-related protein transcripts by sugars is dependent on leaf developmental stage.

Soluble sugars have been found to regulate a number of genes involved in functions associated with sink metabolism, defense reactions and photosynthesis. As viruses and pathogens induce the expression of pathogenesis-related (PR) protein genes and have also been reported to lead to localized sugar accumulation in leaves, it was investigated whether a salicylic acid-independent but sugar-dependent pathway for PR-protein gene induction may exist in plant cells. Leaf discs of tobacco plants were floated on different sugar solutions, transcript accumulation and salicylic acid (SA) levels were subsequently determined. PR-Q and PAR-1 transcripts were found to be inducible by glucose, fructose and sucrose. No significant change in SA content could be detected, following incubation. On the other hand, SAR8.2 transcripts were repressed by elevated levels of soluble sugars and sorbitol, respectively, suggesting sensitivity to turgor pressure. Since leaves undergo sink to source transition during growth, sugar responsiveness was investigated in leaves of different developmental stages. Interestingly, induction of PR-Q and PAR-1 by soluble sugars was essentially restricted to fully expanded leaves and was independent of plant age. Induction by salicylate was not confined to the source capacity of a leaf but was dependent on the age of the respective leaf. Repression of transcripts encoding photosynthetic genes (ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcS) and chlorophyll a/b binding protein (cab) by soluble sugars were largely independent from the leaf developmental state. These findings hint to the possibility of salicylic acid-independent defense reactions of plants against pathogens by induction of a set of PR proteins in source leaves. Furthermore, the data suggest different mechanisms for the induction of PR-protein genes and the repression of photosynthetic genes by soluble sugars.

Carbohydrate Metabolism↗

PubMed2002

Effects of nursing mothers on rPer1 and rPer2 circadian expressions in the neonatal rat suprachiasmatic nuclei vary with developmental stage.

The ability of nursing mothers to entrain the circadian pacemaker of rat pups was examined by measuring the rat Per1 (rPer1) and rPer2 expression levels in the suprachiasmatic nuclei (SCN). Newborn rats from mothers under a light-dark cycle (LD) were blinded immediately after birth and reared by foster mothers under either LD (LD blind pups) or reversed light-dark cycle (DL; DL blind pups). At postnatal day (P)6, small but significant phase differences were observed in the circadian gene expression rhythms of the SCN not only between the blind and sighted pups, but also between the two groups of blind pups, indicating the involvement of both free-running and maternal influence in phase-resetting the circadian rhythms of blind pups. However, from P6 to P13 the circadian rhythms of both LD and DL blind pups showed phase delays of similar extent, which suggests that the influence of nursing mothers was lost. From P13 to P20 (the day of weaning), the rPer1 and rPer2 rhythms phase-shifted in a different manner, the rPer2 rhythm being related more closely to the behavioural rhythm than was the rPer1. This finding suggests a differential influence of mothers on the rPer1 and rPer2 rhythms in the third week of life. It is concluded that the ability of nursing mothers to entrain pup circadian oscillation depends on the developmental stage.

Aging↗

PubMed2003

Genetic and phenotypic analysis of alleles of the Drosophila chromosomal JIL-1 kinase reveals a functional requirement at multiple developmental stages.

In this study we provide a cytological and genetic characterization of the JIL-1 locus in Drosophila. JIL-1 is an essential chromosomal tandem kinase and in JIL-1 null animals chromatin structure is severely perturbed. Using a range of JIL-1 hypomorphic mutations, we show that they form an allelic series. JIL-1 has a strong maternal effect and JIL-1 activity is required at all stages of development, including embryonic, larval, and pupal stages. Furthermore, we identified a new allele of JIL-1, JIL-1(h9), that encodes a truncated protein missing COOH-terminal sequences. Remarkably, the truncated JIL-1 protein can partially restore viability without rescuing the defects in polytene chromosome organization. This suggests that sequences within this region of JIL-1 play an important role in establishing and/or maintaining normal chromatin structure. By analyzing the effects of JIL-1 mutations we provide evidence that JIL-1 function is necessary for the normal progression of several developmental processes at different developmental stages such as oogenesis and segment specification. We propose that JIL-1 may exert such effects by a general regulation of chromatin structure affecting gene expression.

Alleles↗

PubMed1998

Horizontal cells of the rat retina show choline acetyltransferase- and vesicular acetylcholine transporter-like immunoreactivities during early postnatal developmental stages.

We examined cholinergic neurons in the developing rat retina; an antiserum against choline acetyltransferase (ChAT) and an antiserum against vesicular acetylcholine transporter (VAChT) were used. From postnatal day 4 (P4) to P10, ChAT- and VAChT-like immunoreactivities were seen in cells which were located in the outer part of the inner nuclear layer. These cells had relatively large cell bodies and extended several transversely oriented processes. Double fluorescence immunohistochemistry using an antiserum against calbindin D-28K, a specific marker for the horizontal cells, revealed that all of ChAT- or VAChT-labeled cells showed calbindin D-28K-like immunoreactivity. These cells were no longer immunostained after P11. Thus, acetylcholine was considered to be transiently synthesized in the horizontal cells during early postnatal developmental stages in the rat retina.

Acetylcholine↗

PubMed1997

Expression pattern of connexin gene products at the early developmental stages of the mouse cardiovascular system.

The synchronized contraction of myocytes in cardiac muscle requires the structural and functional integrity of the gap junctions present between these cells. Gap junctions are clusters of intercellular channels formed by transmembrane proteins of the connexin (Cx) family. Products of several Cx genes have been identified in the mammalian heart (eg, Cx45, Cx43, Cx40, and Cx37), and their expression was shown to be regulated during the development of the myocardium. Cx43, Cx40, and Cx45 are components of myocyte gap junctions, and it has also been demonstrated that Cx40 was expressed in the endothelial cells of the blood vessels. The aim of the present work was to investigate the expression and regulation of Cx40, Cx43, and Cx37 during the early stages of mouse heart maturation, between 8.5 days post coitum (dpc), when the first rhythmic contractions appear, and 14.5 dpc, when the four-chambered heart is almost completed. At 8.5 dpc, only the reverse-transcriptase polymerase chain reaction technique has allowed identification of Cx43, Cx40, and Cx37 gene transcripts in mouse heart, suggesting a very low activity level of these genes. From 9.5 dpc, all three transcripts became detectable in whole-mount in situ-hybridized embryos, and the most obvious result was the labeling of the vascular system with Cx40 and Cx37 anti-sense riboprobes. Cx40 and Cx37 gene products (transcript and/or protein) were demonstrated to be expressed in the vascular endothelial cells at all stages examined. By contrast, only Cx37 gene products were found in the endothelial cells of the endocardium. In heart, Cx37 was expressed exclusively in these cells, which rules out any direct involvement of this Cx in the propagation of electrical activity between myocytes and the synchronization of contractions. Between 9.5 and 11.5 dpc, Cx40 gene activation in myocytes was demonstrated to proceed according to a caudorostral gradient involving first the primitive atrium and the common ventricular chamber (9.5 dpc) and then the right ventricle (11.5 dpc). During this period of heart morphogenesis, there is clearly a temporary and asymmetrical regionalization of the Cx40 gene expression that is superimposed on the functional regionalization. In addition, comparison of Cx40 and Cx43 distribution at the above developmental stages has shown that these Cxs have overlapping (left ventricle) or complementary (atrial tissue and right ventricle) expression patterns.

Amino Acid Sequence↗

PubMed1989

Integrity of the preimplantation pig blastocyst during expansion and loss of polar trophectoderm (Rauber cells) and the morphology of the embryoblast as an indicator for developmental stage.

The embryonic ectoderm of the pig differentiated and became part of the outer barrier of the blastocyst (earlier formed by the trophectoderm alone) before shedding of the overlying polar trophectoderm around Day 10, thus securing the integrity of the rapidly expanding blastocyst. Ferritin, added to the medium of the blastocyst, was taken up rapidly by trophectoderm cells, but did not reach the blastocoele, and consequently no tracer was found within hypoblast cells. Embryonic ectoderm cells did not absorb the macromolecule, before or after loss of the polar trophectoderm. When ferritin was injected into the blastocoele, trophectoderm, hypoblast and embryoblast cells all absorbed the tracer. At Day 11, blastocyst diameter and embryoblast cell number varied widely and were hardly correlated. We suggest that embryoblast development may be a more reliable indicator for the developmental stage of a blastocyst than its diameter, which may merely be an indication of the viability of the trophoblast.

Animals↗

PubMed1993

Treatment of fish parasites. 11. Morphogenesis of Henneguya laterocapsulata Landsberg, 1987 (Myxosporea, Myxozoa), and the effects of a new triazine derivative, HOE 092 V, on its developmental stages: a light and electron microscopy study.

The ultrastructure of sporogenesis was studied in Henneguya laterocapsulata parasitizing the skin of hybrid catfish (Clarias gariepinus x Heterobranchus bidorsalis) in Nigeria. Sporogenesis started when a generative cell was surrounded by a second nondividing cell (i.e., envelope cell). By subsequent divisions of the generative cell, ten cells were produced, which finally became arranged into two spore-producing units. Each unit consisted of a binucleate sporoplasm, two capsulogenic cells, and two valvogenic cells. Apparently capsulogenesis, valvogenesis, and sporoplasm differentiation occurred concomitantly. In research for chemotherapy of fish parasitized by myxosporeans a new triazine derivative, 2-[3,5-alpha-dichloro-4-(4-methyl-sulfonylphenoxy)-phenyl]-1-me thy l- hexahydro-1,2,4-triazine-3,5-dion (HOE 092 V), was tested in vivo against the uni- and multicellular developmental stages of H. laterocapsulata. Naturally infected catfish were incubated in water containing 0, 2.5, 5, and 10 micrograms HOE 092 V/ml or the pure solvent for 3 h. After the fish had been returned into fresh water, they were killed 1 day after the treatment and the plasmodia were studied by means of light and transmission electron microscopy. Starting with a dose of 2.5 micrograms HOE 092 V/ml, the pericyte's outer membrane was broken in the bi- and multicellular stages. The number of ribosomes in the bi- and multicellular stages decreased. In the multicellular stages the rough endoplasmic reticula of the capsulogenic cells were enlarged. Treatment with 5 micrograms HOE 092 V/ml led to breaks in the limiting outer membranes of the capsulogenic cells and to vacuolization of their peripheral cytoplasm. In early prespore stages a decrease in the number of spherical inclusions was recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Differential myelinogenic capacity of specific developmental stages of the oligodendrocyte lineage upon transplantation into hypomyelinating hosts.

The capacity of oligodendrocytes (OLs) and their progenitors to migrate, proliferate, and differentiate in vivo was evaluated by transplanting highly enriched populations of sequential stages of the OL lineage (A2B5+O4-, O4+GalC-, and GalC+) into the telencephalon of the hypomyelinating mouse, shiverer. The shiverer mouse neither expresses the major myelin basic protein (MBP) nor makes normal myelin due to a large deletion in the gene for MBP. Thirty days after transplantation, serial 225 micron sections of the host brain were immunostained with antiserum to MBP and analyzed by confocal microscopy. The presence of MBP+ patches of myelin in the otherwise MBP- host brain allowed a retrospective analysis of the myelinogenic activity of the transplanted progenitors cells. Both the extent of MBP+ myelin and the location of MBP+ structures relative to the initial site of cell deposition were highly dependent on the developmental stage of the transplanted cells. Specifically, A2B5+O4- OL progenitors migrated distances of > or = 600 microns and produced MBP+ patches in nearly every slice of the host brain. An average of over 250 separate patches were found per host brain, some of which had cross-sectional areas of > 250,000 microns2 containing as many as 60 MBP+ OL cell bodies, and with densities of myelination rivaling that of normal brain. In marked contrast, transplantation of O4+GalC- cells produced only small (1,000-25,000 microns2), scattered (25-40 per brain) patches of MBP+ myelin containing one to five cell bodies, all of which were within 50 microns of the needle track or the nearest ventricular surface. GalC+ cells produced MBP+ myelin at a level similar to that of O4+CalC- cells. These data suggest that the developmental transition of OL progenitors from the O4- to the O4+ phenotype is accompanied by a dramatic reduction in the innate capacity of the cells to migrate and survive in vivo. The use of developmentally identified, enriched populations of OL progenitor cells offers the opportunity for more precise analyses of transplantation and remyelination behavior, and relates to clinically relevant studies indicating that contaminant cell types can seriously interfere with the stable integration of donor tissue into the host.

Animals↗

PubMed1990

Toxicity of cyclosporin A (CsA) against developmental stages of Schistosoma mansoni in mice.

It has been shown elsewhere that the immunosuppressive drug cyclosporin A (CsA) exerts profound schistosomicidal activity when given to infected mice via a multiple administration regime. We show here that a single treatment regime also effects significant reductions in worm burden. Moreover, drug efficacy is maintained at CsA concentrations shown to be subimmunosuppressive in other systems. Subcutaneous treatment effected higher levels of schistosomicidal activity than intraperitoneal or oral treatment, irrespective of whether the drug was given prior to or during infection. Topical application of CsA to the skin site of cercarial penetration, prior to infection resulted in no reduction in worm burden. Systemic release of CsA from a slowly adsorbed, oil-based drug-vehicle combination effected greater levels of killing than when CsA was dissolved in an aqueous drug vehicle. All developmental stages of Schistosoma mansoni were susceptible to killing by a single dose of CsA but, in the case of liver-stage worms, an increased concentration of drug and a longer period between treatment and portal perfusion were needed for killing to be measurable as a reduction in worm numbers.

Adjuvants, Pharmaceutic↗

PubMed2002

[Studies upon behaviour of snails in anthropogenically changed water environment. 1. Locomotor activity of Lymnaea stagnalis (L.), with regard to subpopulations infected with developmental stages of digeneans].

The aim of the paper was to analyse the locomotor activity of snails, Lymnaea stagnalis, with regard to physico-chemical properties of water in an inhabited reservoir and parasitic infection. The material was collected in selected anthropogenic water environments situated in the Upper Silesian Industrial Region (sinkhole ponds, sand- and clay-excavations). The locomotor activity of each snail was analysed in laboratory conditions by designation of number of penetrated segments, marked in tanks filled with water originating from a given reservoir, during 15', with intervals of 1'. It was observed the significant relationship between locomotor activity of examined snails and the water carbonaceous hardness (r = -0,812, at range of the independent variable 173.0-863.5 mg CaCO3/dm3). Correlation coefficients with other physico-chemical parameters of water were close to zero. Locomotion of snails infected with developmental stages of digenetic trematodes was significantly lower comparing to non-infected individuals. Locomotor activity of these former ones was dependend more on degree of the digestive gland damage by the parasite than on the infection agent.

Animals↗

PubMed1999

B cells are programmed to activate kappa and lambda for rearrangement at consecutive developmental stages.

Kappa and lambda, the two types of immunoglobulin light (L) chains present in mammals, contribute differently to the L chain pool of each species. Here we show that the extreme preponderance of kappa in the mouse results from programmed sequential activation of the kappa and lambda loci. Activation--a prerequisite of rearrangement--was monitored by analyzing transcription of unrearranged J-C clusters. Upon in vitro differentiation of a rearrangement-deficient pro/pre-B line, germ-line transcripts of the lambda J-C clusters, that are newly described here, became detectable 2 days later than their counterparts of J-C kappa. Clear differences could also be observed in vivo: germ-line transcripts of kappa were already present in large B220+ CD25+ pre B-II cells whereas germ-line lambda transcripts first became detectable at the consecutive developmental stage of small B220+ CD25+ pre-B-II cells. This activation pattern was found to be identical in mice which can not rearrange kappa due to a targeted deletion or inactivation of kappa. This suggests that pre-B-II cells follow a hit-and-run mechanism of development which includes programmed transitions and differential activation of the L chain loci, i.e. kappa first, then lambda. Thus, privileged activation of kappa might be the decisive factor in setting the 10:1 ratio of kappa to lambda present in the mouse.

Animals↗