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PubMed2004

Effect of white grub developmental stage on susceptibility to entomopathogenic nematodes.

The pathogenicity of the entomopathogenic nematodes Heterorhabditis bacteriophora Poinar and Steinernema scarabaei Stock & Koppenhöfer against different developmental stages of the Japanese beetle, Popillia japonica Newman, and the oriental beetle, Anomala (=Exomala) orientalis Waterhouse, were studied under laboratory conditions. The efficacy of S. scarabaei did not differ between second and third instars in P. japonica or A. orientalis or between small (young) and large (older) third instars in A. orientalis. However, H. bacteriophora efficacy decreased from first over second to third instar and also from small third instars to large third instars in A. orientalis but did not differ significantly between P. japonica larval stages. Once A. orientalis third instars had purged their intestines in preparation for pupation, no significant mortality by S. scarabaei and H. bacteriophora was observed. In contrast, P. japonica susceptibility to both nematode species gradually decreased from stage to stage from actively feeding third instars to pupae. In two additional experiments, we found no difference in Steinernema glaseri (Steiner) susceptibility between second and third instars of A. orientalis but an increase in S. scarabaei susceptibility from the second to third instar of Asiatic garden beetle, Maladera castanea (Arrow). Our observations combined with those of previous studies with other nematode and white grub species show that nematode efficacy against white grub developmental stages varies with white grub and nematodes species, and no generalization can be made.

Animals↗

PubMed1976

Effects of 60Co irradiation of the early developmental stages of an ixodid tick, Hyalomma anatolicum.

Various developmental stages of Hyalomma anatolicum were subjected to a range of doses of 60Co radiation from 0-10 000 R, and their subsequent development was observed. Some of these ticks were infected with Theileria annulata. Doses of 2000 R and over prevented all but a very limited development of ticks. After 1000 R a proportion of exposed individuals continued development in a near-normal manner. Lower doses had proportionately less effect. 1000 R to ticks infected with T. annulata failed to prevent transmission of typical theileriasis to calves.

Animals↗

PubMed1995

The developmental stage of inactivation of rye origin rRNA genes in the embryo and endosperm of wheat x rye F1 hybrids.

To identify the developmental stage during which the preferential inactivation of rRNA genes from the rye parent occurs in wheat x rye hybrids, nucleolar activity was evaluated in the embryo and endosperm of developing seeds of the hybrids. The hybrids were obtained from crosses of euploid and aneuploid lines of hexaploid wheat, Triticum aestivum cv. Chinese Spring, with rye, Secale cereale cv. Centeio do Alto. The number of nucleolar organizing regions (NORs) and nucleoli present in the embryo and endosperm cells of wheat, and wheat x rye F1 hybrids, at different times after fertilization was scored by silver staining. The inactivation of rDNA of rye origin in F1 hybrids occurs simultaneously in the embryo and in the endosperm between 4 and 5 days after fertilization, when these have been through six and 10 cell cycles respectively. We conclude that the genomic interactions leading to the inactivation of the rye origin rDNA is a time-dependent process, related to the developmental stage and independent of the number of cell cycles (DNA replication rounds) they have been through.

Cell Count↗

PubMed2006

Relationship between time elapsed after human chorionic gonadotropin administration and developmental stage in porcine embryos collected from prepubertal gilts.

We examined the relationship between the time elapsed after human chorionic gonadotropin (hCG) administration and developmental stage of porcine embryos after collection. Prepubertal gilts, 7 to 8 months old, were given 1500 IU equine chorionic gonadotropin (eCG) intramuscularly, followed by 500 IU hCG 72 h later. The treated gilts were inseminated artificially on Day 1 (Day 0=the day of hCG administration) and on Day 2. Embryos were collected surgically on Day 6 (140, 144, and 147 h after hCG administration) or on Day 7 (164, 168, and 171 h), and the developmental stages of the collected embryos were examined. From 75.2% (276/367) of the prepubertal gilts treated with hormones, we collected an average of 20.7 embryos per gilt with normal morphology. At 140 h after hCG administration, morulae (54.4%) could be collected. At 144 h, morulae and early blastocysts (57.7% and 28.9%, respectively) were collected. By 147 h, the proportion of embryos at the blastocyst to expanded blastocyst stages had increased (10.0%). From 164 h to 171 h, expanding or expanded blastocysts of more than 200 microm in diameter and hatched blastocysts could be collected. The proportion of hatched blastocysts increased from 3.2% (164 h) to 41.0% (171 h). These results suggests that although the number of ovulations differed among gilts, porcine embryos at the appropriate stages can be collected efficiently by controlling the time elapsed between hCG administration and embryo collection.

Animals↗

PubMedDate not supplied

Developmental stage of the dentition and speech sound production in a series of first-grade schoolchildren.

This study was undertaken to investigate the effect of developmental stage of the dentition on speech sound production in children with and without articulatory speech disorders. In the whole sample, there were 281 subjects, mean age 7.5 years (SD 0.4). The stage of the eruption of the permanent incisors was calculated as the percentage height of each tooth of the mean crown height of the corresponding tooth in a group of 252 young adults. Eruptional stage of the first permanent molars was classified into three categories. Articulatory disorders were diagnosed by one experienced speech therapist and phoniatrician using the Remes Articulation Test [Remes, 1975] for the Finnish language. The results showed a wide interindividual variation in developmental stage of the dentition in a group of 7-year-old children with a tendency of the first permanent molars but not the incisors to erupt earlier in girls than in boys. Boys had a higher frequency of misarticulations estimated to need treatment than did girls. The present results indicate that during eruption of permanent teeth it is more important to draw attention to symmetrical eruption and to individual timing pattern rather than to the mean values of tooth eruption in subjects of the same age. The findings also suggest a decreasing risk of faulty speech sound production with advancing eruption of some permanent teeth still present in 7-year-old children.

Child↗

PubMed1988

Analysis of the developmental stages of Pneumocystis carinii, in vitro.

Rat derived Pneumocystis carinii cultured in vitro was analyzed by a variety of light microscopic and staining techniques for identification of developmental stages and changes in these populations over time in culture. Evaluation of culture dynamics based on a limited number of life cycle stages indicated that trophic replication contributed significantly to the observed growth in vitro. Identification of additional life cycle stages, particularly early cyst forms, suggested that the process of maturation from early precyst to mature cyst may also contribute to the net growth. All developmental stages identified from culture were verified by their presence in stained impression smears of infected rat lung. Based on these data, a tentative life cycle for P. carinii in vitro has been proposed.

Animals↗

PubMed1975

Variation in average unit chain length of glycogen in relation to developmental stage in Blastocladiella emersonii.

Synchronous, single generations of Blastocladiella emersonii were grown along either the ordinary colorless or resistant sporangial plant pathways. Samples of cells were withdrawn at different developmental stages and glycogen was extracted, purified, debranched by isoamylase treatment, and its component unit chains separated by gel permeation chromatography. The elution profiles showed the distribution of unit chains. Average unit chain length was determined for plants at different developmental stages and shown to vary between 9 and 16. Some of these variations were correlated with other developmental events in the fungus.

Amylases↗

PubMed2003

Effect of developmental stage of embryo at freezing on pregnancy outcome of frozen-thawed embryo transfer.

BACKGROUND: The study aim was to investigate the impact of the developmental stage of embryos on pregnancy outcome of frozen embryo transfer (FET). METHODS: The survival rates of embryos after thawing and pregnancy outcome following FET were compared retrospectively between three cryopreservation strategies utilizing either zygote, day 2 or day 3 embryo freezing. RESULTS: A total of 4006 embryos was analysed in 1657 thaw cycles. The highest (P < 0.0001) survival rate (all cells survived) was observed for zygotes (86.5%), followed by day 2 (61.7%) and day 3 (43.1%) embryos. FET was performed in 1586 (95.7%) of all thaw cycles, resulting in overall clinical pregnancy and implantation rates of 20.7 and 14.2% respectively. The delivery rate per transfer was 16.5%, and live birth rate per transferred embryo 11%. There were no significant differences in clinical pregnancy, implantation, delivery and birth rates between frozen zygote, day 2 and 3 embryo transfers. However, an elevated miscarriage rate was observed in the day 3 group (45%) compared with zygotes (21.3%; P = 0.049) and day 2 embryos (18.3%; P = 0.004). The overall efficacy of FET (birth rate per thawed embryo) was 7.3%. The efficacy was lower in day 3 group (4.2%) than in the zygote (7.1%; P = 0.082) and day 2 (7.6%; P = 0.027) groups. CONCLUSIONS: The developmental stage of embryos at freezing has a profound effect on their post-thaw survival, but seems to have little effect on rates of clinical pregnancy, implantation, delivery and birth after FET. The elevated miscarriage rate for day 3 frozen embryo transfers may be caused by damage during freeze-thaw procedures. The low survival rate and elevated miscarriage rate were both responsible for a reduced overall efficacy for day 3 FET when compared with zygotes and day 2 embryos.

Abortion, Spontaneous↗

PubMed2004

Expression of Babesia equi EMA-1 and EMA-2 during merozoite developmental stages in erythrocyte and their interaction with erythrocytic membrane skeleton.

In the present study, we investigated the cellular localizations and expression patterns of equi merozoite antigens (EMA) -1 and -2 of Babesia equi during its asexual erythrocytic-developmental cycle using anti-EMA-1t or -2t mono-specific mouse serum. Indirect fluorescent antibody tests demonstrated that EMA-1 and EMA-2 were not expressed in all the erythrocytic-developmental stages of the merozoites and that these two antigens were co-expressed during the early developmental stages. Additionally, it was shown that EMA-1 and EMA-2 were mutually expressed on the surface of extra-erythrocytic merozoites and also that the intra-erythrocytic merozoites shed only EMA-2 antigen in the infected erythrocytic cytoplasm or inside the membrane surface. The specific binding of EMA-2 to a Triton X-100-insoluble horse erythrocyte membrane fraction was also demonstrated. These findings facilitate our understanding of the biological roles of merozoite surface proteins of B. equi and our investigation for new drug targets.

Animals↗

PubMed2006

Dynamic of the genetic structure of bacterial and fungal communities at different developmental stages of Medicago truncatula Gaertn. cv. Jemalong line J5.

The genetic structure of bacterial and fungal communities was characterized in the rhizosphere of Medicago truncatula Gaertn. cv. Jemalong line J5 at five developmental stages (three vegetative and two reproductive stages), and in three compartments (bulk soil, rhizosphere soil and root tissues). The genetic structure of microbial communities was determined by cultivation-independent methods using directly extracted DNA that was characterized by automated ribosomal intergenic spacer analysis (ARISA). Principal component analyses (PCA) indicate that, for all developmental stages, the genetic structure of microbial communities differed significantly by compartment, with a major shift in the community in root tissues corresponding to the most intimate compartment with the plant. Differences were also recorded during plant development, the most significant being observed during the transition between vegetative and reproductive stages. Throughout this period, plants were shown to establish the highest level of symbiotic association (mycorrhization, nodulation) with arbuscular mycorrhizal fungi and Rhizobia. During the reproductive stages, the dynamics of the genetic structure differed between bacterial and fungal communities. At the last reproductive stage, the genetic structure of bacterial communities became close to that recorded during the first vegetative stages, suggesting a resilience phenomenon, whereas the genetic structure of fungal communities remained different from the vegetative stages and also from the early reproductive stages, suggesting a persistence of the rhizosphere effect.

Bacteria↗

PubMed2005

[Gene expression of p38 mitogen-activated protein kinase and its MAPKKs in skin at different developmental stages and its possible biological significance].

OBJECTIVE: To investigate the gene expression of p38 mitogen-activated protein kinase (p38MAPK) and its upstream signaling molecule (mkk3 and mkk6) in fetal skin at different developmental stages and postnatal skin and its potential biological significance. METHODS: The fetal skin biopsies were obtained from human embryo of spontaneous abortion at gestational ages from 13 to 32 weeks and postnatal skin specimens were collected from patients (4-16 years) undergoing plastic surgery. After the morphological characteristics of skins at different developmental stages were detected with pathological methods, the gene expressions of p38MAPK, mkk3 and mkk6 in skins were examined with reverse transcription-polymerase chain reaction analysis (RT-PCR). RESULTS: The gene expressions of p38MAPK, mkk3 and mkk6 could all be detected in fetal and postnatal skins. In fetal skins, these 3 genes were strongly expressed. Along with fetal growth and development, the gene expressions of p38MAPK and its upstream signaling molecules were faded gradually. In postnatal skin, the mRNA contents of these 3 genes were significantly decreased in comparison with those in fetal skin (P < 0.01). CONCLUSION: p38 MAPK mediated signal pathways might be involved in the skin development at embryonic stage and in the determination of cutaneous structure and function, and also in wound healing at postnatal stage. The relative increment of these gene transcription in younger fetal skin might be one of the reasons why cutaneous cells proliferate rapidly and the wounds heal without scar.

Adolescent↗

PubMed2004

Expression of peroxisome proliferator-activated receptors in zebrafish (Danio rerio) depending on gender and developmental stage.

Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors involved in embryo development and differentiation of several tissues in mammals. The aim of the present study was to investigate the possible differential expression of the three PPAR subtypes (PPARalpha, PPARbeta, and PPARgamma) in relation to gender and developmental stage in zebrafish. For this purpose PPAR expression was assessed by immunohistochemistry in 7-day-old larvae, 1-month-old juveniles, and 1-year-old adults. Additionally, the activity of peroxisomal acyl-CoA oxidase (AOX), a gene regulated by PPARs, and the volume density of catalase-immunolabeled liver peroxisomes (V(VP)) was examined. No significant gender-related differences were detected in the tissue distribution of the three PPAR subtypes or in peroxisomal AOX activity and V(VP). The percentage of PPARbeta-positive hepatocytes was significantly higher in females than in males suggesting a specific regulatory role of this subtype in female zebrafish. The three PPAR subtypes were already expressed at the larval stage, with a similar tissue distribution pattern to that found in adults. For all stages, PPARalpha and PPARgamma were expressed at higher levels than PPARbeta, and PPARbeta immunolabeling was stronger in juveniles than in larval or adult stages. The percentages of hepatocyte nuclei immunolabeled for PPARs was higher in early developmental stages than in adults, similarly to AOX activity and V(VP). In conclusion, our results indicate that PPAR expression, the activity of its target gene AOX, and peroxisomal biogenesis are developmentally modulated in zebrafish.

Acyl-CoA Oxidase↗

PubMed2004

Neurites from trigeminal ganglion explants grown in vitro are repelled or attracted by tooth-related tissues depending on developmental stage.

Although neurite attracting factors are present in the developing dental pulp and trigeminal ganglion (TG) axons can respond to such factors, nerve fibres do not enter the tooth pulp until a late developmental stage compared with surrounding tissues supplied by the TG. This suggests that the dental pulp secretes neurite growth inhibitory molecules. Semaphorins represent one group of substances, which can inhibit/repel growing neurites. The aims of the present study were to investigate if dental tissue explants inhibit/repel neurite growth from TGs at some developmental stages in vitro, and if so, to seek evidence for or against a participation of semaphorins in that interaction. By co-culturing mandibular or dental epithelial and mesenchymal tissue explants and TGs in collagen gels, we found that embryonic day 11 (E11) mandibular and E13 dental mesenchymal explants repel neurites from corresponding TGs. Repulsion was replaced by attraction if tissues from late embryonic or early postnatal mice (E17-postnatal day 5) were used. Using semi-quantitative reverse transcription/polymerase chain reaction we showed that a number of semaphorins were expressed by tooth-related mesenchyme collected from embryonic and postnatal mice. The expression of some semaphorins (3A, 3C, 3F, 4F, 5B, 6A, 6B and 6C) was high early in development and then decreased in a temporal pattern that correlated with neurite inhibitory/repulsive effects of dental mesenchyme observed in co-cultures. The expression of other semaphorins increased with development (3B, 4A and 7A), whilst others varied irregularly or remained at a fairly constant level (3E, 4B, 4C, 4D, 4G and 5A). Immunohistochemistry was used to determine if tooth-related nerve fibres possess neuropilins. This revealed that axons surrounding embryonic tooth buds express neuropilin-1, but not neuropilin-2. In postnatal teeth, nerve fibres located within the tooth pulp were immunonegative for neuropilin-1 and neuropilin-2. We conclude that developing mandibular/dental mesenchyme can inhibit/repel neurite growth in vitro. Our results support the hypothesis that semaphorins may be involved in this interaction.

Animals↗

PubMed1989

Partial denervation of the rat soleus muscle at two different developmental stages.

Rat soleus muscles were partially denervated at two developmental stages. The L5 ventral ramus was sectioned in rats which were 4-6 days old, when the motor unit size of soleus muscles was still large, and at 17-19 days, when motor unit territory reached its adult value. The response of axons in the L4 ventral ramus to this procedure was then investigated. The removal of the L5 ventral ramus at 4-6 days results in an initial brief increase of motor unit size, after which the motor units retain the territory they occupied at 4-6 days. After removal of the L5 ventral ramus at 17-19 days, the L4 ventral ramus is able to expand to occupy a territory comparable in size to that of animals operated at 4-6 days. In both cases the final percentage of mean motor unit tension is two- to three-fold greater than that in normal muscles. Although the final motor unit territory is similar for both groups, it is achieved by different mechanisms. In animals operated on at 4-6 days the normal elimination of terminals does not occur, and the large neonatal motor units are retained, whereas in animals operated on at 17-19 days the peripheral field of L4 axons expands by axonal sprouting.

Aging↗

PubMed1994

Ultrastructural localization of monoclonal antibodies against Pneumocystis carinii. Differentiation between developmental stage and host origin.

The ultrastructural immunolocalization of target antigens recognized by two monoclonal antibodies against Pneumocystis carinii was investigated using both human- and rat-derived organism. Labelling was seen using both cryo electron microscopy and postembedding in Epon after fixation in glutaraldehyde. The antibodies showed different host species- and developmental stage specificity. One of the antibodies reacted with the outer membrane of all developmental stages of human-derived but not rat-derived organisms, whereas the other reacted only with the cyst form. The distribution of the latter was similar to that reported for methenamine silver, a widely used cytochemical stain for the parasite, and reacted with both human- and rat-derived organisms. The antibodies described appear to be useful markers in studies on the differentiation of Pneumocystis carinii.

Animals↗

PubMed2004

Glutathione S-transferase in the developmental stages of the insect Apis mellifera macedonica.

We investigated the pattern of glutathione S-transferase (GST) activity in the course of the development of Apis mellifera macedonica. GST activity is present in all developmental stages of A. mellifera macedonica. The highest activity towards the substrate 1-chloro-2,4-dinitrobenzene (CDNB) is found in the adult stage and the lowest in the egg. The kinetic characteristics of the whole enzyme change as the insect develops. Significant changes are observed in substrate specificity, inhibitor sensitivity and V(max). The number of isoenzymes and their rate of expression vary as the insect develops. However, two main isoenzymes are present in all developmental stages, one in the alkaline area and the other in the acidic. While in the larval stage the acidic isoenzyme is expressed at a slightly higher rate (52.2% over 47.8% for the alkaline isoenzyme), in the adult stage, the rate is reversed dramatically (13.24% and 84.2%, respectively).

Animals↗

PubMed1994

Dystrophin-related protein is found in the central nervous system of mice at various developmental stages, especially at the postsynaptic membrane.

Dystrophin deficiency is known to be the cause of X-linked Duchenne muscular dystrophy (DMD). A recently cloned B3-cDNA shares 80% homology with the C-terminus and actin-binding portion of dystrophin. This autosome-derived gene product is called dystrophin-related protein (DRP). DRP is known to exist in fetal muscles even in mdx mice, an animal model for X-linked DMD, but not in mature mouse muscles. We raised a polyclonal antibody against a B3-unique amino acid sequence (Ab-LDP) and investigated the existence and distribution of DRP in the central nervous system (CNS) tissues of mdx and normal control B10 mice at various stages of development using immunoblotting and immunohistochemical methods. The former shows that DRP exists in the CNS of both B10 and mdx mice, regardless of the developmental stage, with the exception that the 420 kDa DRP band of the 15-day fetus is faint. In immunohistochemical studies, the choroid plexus, some neurons, glial cels, pia mater, and blood vessels were stained with Ab-LDP. Staining intensity did not differ between B10 and mdx mice or between developmental stages except that the 15-day fetus stained only faintly. This is in contrast to the results obtained for muscles in which DRP localized to muscle membrane in embryo decreases and is assembled at the neuromuscular junction in adults. In addition, an electron microscopic study on the cerebral cortex from adult B10 mice was also performed and revealed Ab-LDP staining of the postsynaptic membrane of dendrite and the rough endoplasmic reticulum of neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1990

Partial purification and characterization of cysteine proteinases from various developmental stages of Paragonimus westermani.

1. During development of Paragonimus westermani, larvae develop during migration within the host, and adult worms feed on pulmonary tissues, causing significant pathology in the mammalian host. In this report acidic extracts of various developmental stages (metacercariae and worms at one, two and three months of development) were examined for cysteine proteinase activity. 2. A soluble thiol-dependent proteinase activity with a native molecular weight of approximately 20,000 was isolated and partially purified. 3. The enzymes purified from the various developmental stages of the parasite had maximal activity at acidic pH and showed inhibitor susceptibilities similar to the vertebrate acidic cysteine proteinases. 4. Enzymatic activity was stable at pH 5.0 for at least two days when stored at 4 degrees C. 5. It is suggested that these enzymes may be involved in the nutrition of these parasites and/or during penetration and lysis of the tissues.

Animals↗