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PubMedDate not supplied

Genotyping Campylobacter jejuni strains isolated from the gut and oviduct of laying hens.

Campylobacter jejuni frequently colonizes the avian intestine. Recent evidence suggests that this organism can also colonize the oviduct of laying hens. However, the source and role of this colonization are unknown. Isolates from the ceca, cloacae, and oviducts of 11 laying hens in three intensive egg-producing flocks were genotyped by Fla typing with the restriction fragment length polymorphism of the polymerase chain reaction product of the flaA and flaB genes (fla typing) and pulsed-field gel electrophoresis (PFGE). A diversity in fla types and PFGE types was observed within and between flocks. Individual birds could be colonized by different genotypes at various intestinal and oviduct sites. However, the oviduct of individual birds appeared to be colonized by only one genotype at the time of sampling. In two birds, matching isolates investigated from the intestinal and reproductive tracts were genotypically identical but different from those oviduct isolates found in other birds in the same flock. Interestingly, not all cecal isolates appeared to be equally able to colonize the oviduct. These results suggest that oviduct colonization may result from ascending infection via the cloaca and that some strains of C. jejuni may be better adapted than others to oviduct colonization.

Animals↗
PubMed2003

Delayed selfing and resource reallocations in relation to mate availability in the freshwater snail Physa acuta.

We study the influence of mate availability on the mating behavior of the self-fertile, preferentially outcrossing freshwater snail Physa acuta. Previous optimization theory indicated that mating system interacts with life-history traits to influence the age at first reproduction, providing three testable predictions. First, isolated individuals should reproduce later than individuals with available mates in the expectancy of finding a partner and avoiding the cost of inbreeding. Second, resource reallocation to future fecundity is needed for such reproductive delays to evolve. Third, the reproductive delay can be optimized with respect to life-history traits (e.g., survival, growth) and the mating system (inbreeding depression). Our results largely validate these predictions. First, reproduction is significantly delayed in isolated individuals ("selfers") as compared with individuals frequently exposed to mates ("outcrossers"). Second, delayed reproduction is associated with reallocation to future growth, survival, and fecundity, although fecundity is also affected by the mating system (selfing vs. outcrossing). Third, the reproductive delay found (approximately 2 wk) is consistent with quantitative predictions from optimization models. The delay is largely heritable, which might be partly explained by among-family differences in the amount of inbreeding depression (mating system) but not growth or survival.

Animals↗
PubMed1999

Myocarditis and abortion associated with intrauterine infection of sows with porcine circovirus 2.

Porcine circovirus 2 (PCV2) is a recently identified agent that has been associated with postweaning multisystemic wasting syndrome (PMWS) in swine populations. In this report, the potential spectrum of disease associated with PCV2 is expanded by evidence of vertical transmission and associated reproductive failure. PCV2 was isolated from a litter of aborted piglets from a farm experiencing late-term abortions and stillbirths. Severe, diffuse myocarditis was present in 1 piglet associated with extensive immunohistochemical staining for PCV2 antigen. Variable amounts of PCV2 antigen were also present in liver, lung, and kidney of multiple fetuses. The presence of other agents that have been associated with fetal lesions and abortion in swine, including porcine parvovirus, porcine reproductive respiratory syndrome virus, encephalomyocarditis virus, and enterovirus, could not be established.

Abortion, Veterinary↗
PubMed2005

Caste-based differences in gene expression in the polyembryonic wasp Copidosoma floridanum.

The polyembryonic parasitoid Copidosoma floridanum produces two larval castes, soldiers and reproductives, during development within its host. Soldier larvae defend the brood against competitors while reproductive larvae develop into adult wasps. As with other caste-forming insects, the distinct morphological and behavioral features of soldier and reproductive larvae likely involve differential gene expression. In this study we used a bi-directional suppression subtractive hybridization (SSH) approach to isolate differentially expressed genes from C. floridanum soldier and reproductive larvae. We isolated 230 novel expressed sequence tags (ESTs) from the two subtractions (114 soldier/116 reproductive ESTs). Among these ESTs were sequences with significant similarity to genes coding for serine proteinases, proteinase inhibitors, odorant-binding and chemosensory proteins, and cuticular proteins. Also, three novel genes were isolated that resemble one another in conceptual translation and share the cysteine spacing pattern of short scorpion toxins and insect defensins. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of 20 ESTs from the two libraries indicated that 85% were differentially expressed in one caste or the other. We conclude that our SSH strategy was effective in identifying a number of genes differentially expressed in soldier and reproductive larvae and that several of these genes will be useful in characterizing caste-specific gene networks in C. floridanum.

Amino Acid Sequence↗
PubMedDate not supplied

Morphological differentiation of Tritrichomonas foetus from other protozoa of the bovine reproductive tract.

Tritrichomonas foetus is a protozoan parasite associated with reproductive failure in the bovine. Its incidence has effectively been controlled in the UK, as in many other countries, through a policy of testing of breeding animals and the widespread use of artificial insemination (AI). As a result there have been only two cases of bovine trichomoniasis in the UK over the past 20 years. Despite the virtual absence of T. foetus in bovine preputial and vaginal samples, routine examinations have occasionally revealed the presence of motile protozoa which require careful identification. In this paper, the morphological characteristics of T. foetus, and other protozoa isolated from the bovine reproductive tract, are presented.

Animals↗
PubMed1988

Identification and comparison of Campoletis sonorensis virus transcripts expressed from four genomic segments in the insect hosts Campoletis sonorensis and Heliothis virescens.

The Campoletis sonorensis virus (CsV; Polydnaviridae) genome consists of at least 28 closed circular superhelical (SH) DNAs. In this study we used complete clones of four SH DNAs to analyze viral transcription both in the adult parasitic wasp host Campoletis sonorensis (Ichneumonidae) and in the lepidopteran host, Heliothis virescens (Noctuidae). CsV genes are expressed in parasitized H. virescens, but no viral transcripts had been characterized from C. sonorensis until this study. The clones of the SH DNAs B, H, M, and O1 were used to probe Northern blots of poly(A)+ RNA isolated from C. sonorensis reproductive tissue and from parasitized H. virescens larvae. All four SH DNAs hybridized to viral transcripts. SH-H,-M, and -O1 hybridized to messages expressed in both hosts. SH-B and -M hybridized to transcripts that were detected only in either C. sonorensis reproductive tissue or parasitized H. virescens larvae. These results suggest that some CsV genes are expressed in a host-specific manner. In a previous study we identified a family of imperfectly conserved tandemly repeated 540-bp repeat elements on SH-B,-H and -O1 (D. A. Theilmann and M. D. Summers, 1987 J. Virol. 61; 2589-2598). Hybridization of the 540-bp repeat regions to Northern blots showed that they were all homologous to viral transcripts. A cDNA clone of a mRNA that is transcribed from the 540-bp repeat region of SH-B was isolated from a lambda gt 10 library and completely sequenced. The sequence data revealed that the 540-bp repeat element was contained within the open reading frame of this gene. These results indicate that transcribed sequences homologous to the 540-bp repeat elements represent a second gene family to be identified within the CsV genome.

Amino Acid Sequence↗
PubMed1996

Testing models of female reproductive migratory behaviour and population structure in the Caribbean hawksbill turtle, Eretmochelys imbricata, with mtDNA sequences.

Information on the reproductive behaviour and population structure of female hawksbill turtles, Eretmochelys imbricata, is necessary to define conservation priorities for this highly endangered species. Two hypotheses to explain female nest site choice, natal homing and social facilitation, were tested by analyzing mtDNA control region sequences of 103 individuals from seven nesting colonies in the Caribbean and western Atlantic. Under the social facilitation model, newly mature females follow older females to a nesting location, and subsequently use this site for future nesting. This model generates an expectation that female lineages will be homogenized among regional nesting colonies. Contrary to expectations of the social facilitation model, mtDNA lineages were highly structured among western Atlantic nesting colonies. These analyses identified at least 6 female breeding stocks in the Caribbean and western Atlantic and support a natal homing model for recruitment of breeding females. Reproductive populations are effectively isolated over ecological time scales, and recovery plans for this species should include protection at the level of individual nesting colonies.

Animals↗
PubMed1992

Localization of Lom-AG-myotropin I-like substances in the male reproductive and nervous tissue of the locust, Locusta migratoria.

Lom-AG myotropin I (Lom-AG-MTI) was the first peptide to be isolated from the male accessory reproductive glands of the locust, Locust migratoria. It shows no sequence similarity to any of the peptides identified from vertebrate or invertebrate tissues. A polyclonal antiserum was used to localize Lom-AG-MTI-like material in the male reproductive system and nervous system of the locust. Immunoreactivity was found in two of the hyaline gland tubules. In the brain, cell bodies were detected in the photo- and deuterocerebrum as well as the frontal ganglion. Nerve fibers were stained in the neuropils of the brain and throughout the labial nerves into the recurrent nerve. Thoracic and last abdominal ganglia contained neurons which could be stained with Lom-AG-MTI antiserum. The pronounced reactivity in the central nervous system suggests a possible neuroregulatory function of the peptide.

Amino Acid Sequence↗
PubMed2005

Comparative study of carrageenans from reproductive and sterile forms of Tichocarpus crinitus (Gmel.) Rupr (Rhodophyta, Tichocarpaceae).

A comparative study of the structure and properties of the sulfated polysaccharides (carrageenans) isolated from the vegetative and reproductive forms of the red alga Tichocarpus crinitus was performed. The polysaccharides were separated into the gelling (KCl-insoluble) and non-gelling (KCl-soluble) fractions by precipitation with 4% KCl. The total content of polysaccharides extracted from the reproductive form of the alga was 1.8-fold more than that extracted from the vegetative form, and in the first case, the gelling polysaccharides mostly accumulated. The gelling polysaccharides from the vegetative form have the highest molecular weight (354 kD). According to the results of FT-IR and 13C-NMR spectroscopy, the gelling polysaccharide fractions from both forms are kappa/beta carrageenans. The differences concern the content of the kappa- and beta-disaccharide units and the presence of a small content of the sulfated disaccharide segments (precursors of the kappa-carrageenans) in the polysaccharide from the reproductive form of the alga. The non-gelling polysaccharide fractions from both forms of the plant are mixtures of sulfated galactans with a low content of 3,6-anhydrogalactose.

Carrageenan↗
PubMed2006

Asymmetrical reinforcement and Wolbachia infection in Drosophila.

Reinforcement refers to the evolution of increased mating discrimination against heterospecific individuals in zones of geographic overlap and can be considered a final stage in the speciation process. One the factors that may affect reinforcement is the degree to which hybrid matings result in the permanent loss of genes from a species' gene pool. Matings between females of Drosophila subquinaria and males of D. recens result in high levels of offspring mortality, due to interspecific cytoplasmic incompatibility caused by Wolbachia infection of D. recens. Such hybrid inviability is not manifested in matings between D. recens females and D. subquinaria males. Here we ask whether the asymmetrical hybrid inviability is associated with a corresponding asymmetry in the level of reinforcement. The geographic ranges of D. recens and D. subquinaria were found to overlap across a broad belt of boreal forest in central Canada. Females of D. subquinaria from the zone of sympatry exhibit much stronger levels of discrimination against males of D. recens than do females from allopatric populations. In contrast, such reproductive character displacement is not evident in D. recens, consistent with the expected effects of unidirectional cytoplasmic incompatibility. Furthermore, there is substantial behavioral isolation within D. subquinaria, because females from populations sympatric with D. recens discriminate against allopatric conspecific males, whereas females from populations allopatric with D. recens show no discrimination against any conspecific males. Patterns of general genetic differentiation among populations are not consistent with patterns of behavioral discrimination, which suggests that the behavioral isolation within D. subquinaria results from selection against mating with Wolbachia-infected D. recens. Interspecific cytoplasmic incompatibility may contribute not only to post-mating isolation, an effect already widely recognized, but also to reinforcement, particularly in the uninfected species. The resulting reproductive character displacement not only increases behavioral isolation from the Wolbachia-infected species, but may also lead to behavioral isolation between populations of the uninfected species. Given the widespread occurrence of Wolbachia among insects, it thus appears that there are multiple ways by which these endosymbionts may directly and indirectly contribute to reproductive isolation and speciation.

Animals↗
PubMed2007

Insect gonadotropic peptide hormones: some recent developments.

Gonadotropic peptides are a new generation of peptide hormone regulators of insect reproduction. They have been isolated from ovaries, oviducts, or brains of insects. The subject of this paper is insect peptides that exert stimulatory or inhibitory effects on ovarian development and oocyte maturation. On the basis of the literature data and the results of our investigations, the structure and biological properties of different groups of peptides are presented.

Amino Acid Sequence↗
PubMedDate not supplied

Potential significance of genomic imprinting defects for reproduction and assisted reproductive technology.

Recent studies suggest a possible link between human assisted reproductive technology and genomic imprinting disorders. Assisted reproductive technology includes the isolation, handling and culture of gametes and early embryos at times when imprinted genes are likely to be particularly vulnerable to external influences. Evidence of sex-specific differences in imprint acquisition suggests that male and female germ cells may be susceptible to perturbations in imprinted genes at specific prenatal and postnatal stages. Imprints acquired first during gametogenesis must be maintained during preimplantation development when reprogramming of the overall genome occurs. In this review, we will discuss both new developments in our understanding of genomic imprinting including the mechanisms and timing of imprint erasure, acquisition and maintenance during germ cell development and early embryogenesis as well as the implications of this research for future epigenetic studies in reproduction and assisted reproductive technology.

Angelman Syndrome↗
PubMed1992

Schistosoma mansoni p48 eggshell protein gene: characterization, developmentally regulated expression and comparison to the p14 eggshell protein gene.

Egg production by worm pairs is a major cause of pathogenesis in schistosomiasis. To further the understanding of female reproductive development, we have isolated and characterized a complete copy of an eggshell protein precursor gene, p48. Sequence analysis reveals that the gene has 3 open reading frames and does not contain an intron. One of the open reading frames, ORF1, encodes a polypeptide of 50 kDa which shows strong homology to insect chorion proteins. Determination of the position of the mRNA cap-site facilitated identification of putative regulatory elements in the 5' upstream region of the gene. Some of these elements (e.g., TCACGT) have been shown to play a role in the regulation of chorion gene expression in insects. p48 mRNA is detectable only in mature female worms and the ability to detect the mRNA coincides temporally with worm pairing. Quantitative comparisons, during female reproductive development, of p48 transcripts to those from another eggshell protein precursor gene, p14, show that the p48 mRNA is significantly less abundant than p14 mRNA. In mature female worms, p48 mRNA can only be detected in vitelline cells. Antibodies made against the polypeptide sequence deduced from ORF1 of the p48 gene recognize a 50-kDa molecule in extracts from mature female worms, but not in extracts from immature females or males.

Amino Acid Sequence↗
PubMed1980

A circuit for safe diagnostic electrical stimulation of the human brain.

An electronic circuit for controlled electrical stimulation of the human brain has been designed to optimize safety in charge transfer from electrodes to brain and to eliminate the likelihood of unwanted currents from the neurostimulator resulting from component failure. The circuit schematics feature the following designs: (1) a highly accurate and versatile rate generator 0.5 p.p.s. to 99 in increments of 0.5 p.p.s., (2) symmetrically-biphasic lead and lag pulses of 100 musec duration, (3) photo-isolated driver amplifiers with accurate waveform, reproduction, (4) true biphasic passive-current regulators driven by an isolated battery supply voltage for switch-selectable currents of 0.25 to 5 ma or variable current regulation, (5) accurate current and voltage waveform monitors that isolate the stimulating electrodes from the monitors, and (6) capacity-coupled outputs to guarantee no net D.C. component at the end of each biphasic pulse. Relay-switching circuits are also shown that allow sequential stimulation and recording from one or several electrodes. This neurostimulator has been in use for over two years without evidence of electrolytic damage at identifiable electrode tips. The utility of simultaneous stimulation of several different electrodes at safe charge levels is described.

Amygdala↗
PubMed2006

Effects of forest fragmentation on phenological patterns and reproductive success of the tropical dry forest tree Ceiba aesculifolia.

Spatial isolation caused by forest fragmentation and temporal isolation caused by asynchronous flowering of plants have been proposed as important factors that affect the reproduction ofplant populations. In a 4-year study, we determined the effects of forest fragmentation and spatial isolation on flowering phenology and reproductive success of the tropical tree Ceiba aesculifolia ([Kunth] Britton & Rose). We conducted our study in the dry forest of Mexico and compared populations in two habitat conditions based on density and environmental conditions: (1) disturbed habitat (four populations of < or =3 reproductive individuals/ha surrounded by agriculturalfields or pastures) and (2) undisturbed habitat (three populations of groups of >6 reproductive individuals/ha surrounded by undisturbed mature forest). We compared the following variables within these populations over 4 years: flowering overlap, proportion of individuals with flowers and fruit, total flower production, total fruit production, fruit set, seed production, and seed abortion. Little overlap in flowering occurred among the populations in the two habitat conditions. The flowering period of trees in the disturbed habitat initiated between 15 to 20 days before the flowering period of trees in the undisturbed habitat during 3 years. Flowering of trees in the undisturbed habitat peaked at the end of the flowering period of the trees in the disturbed habitat. The proportion of trees that flowered was greater in the undisturbed habitat. Nevertheless, total flower production was greater in the disturbed habitat and these differences were maintained across 3 years. The proportion of individuals that produced fruit did not differ across habitat conditions but did differ across years. Total fruit production was greater in the disturbed habitat, but fruit set and seed production were the same across years and between habitat conditions. Seed abortion varied over years between habitats. We concluded that forest fragmentation does not negatively affect the reproductive success of C. aesculifolia It appears that the highly mobile bat pollinators maintain reproductive connectivity between trees in both habitats.

Animals↗
PubMed1993

[Gardnerella vaginalis in infections of reproductive organs].

The study was aimed at multidirectional studies on bacteria isolated from smears from vagina and cervix uteri in 226 patients with inflammatory states of their reproductive organs. Most frequently isolated aerobic bacteria were Gram-negative--27%, mainly E. coli, and Enterococcus faecalis--in 18% of cases. Anaerobic bacteria were isolated in 81% of cases: Gardnerella vaginalis was isolated in 28% and Lactobacillus in 53% of cases. Other anaerobic bacteria were: Peptococcus asaccharolyticus (15.5%), Streptococcus sp. (15.9%), and Bacteroides melaninogenicus (14.1%). Gardnerella vaginalis was most frequently found in chronic cases of vaginosis (41.7%). All strains of G. vaginalis were susceptible to cefotaxime, while 15-40% of them were resistant to gentamycin, tetracycline and metronidazole.

Chronic Disease↗
PubMed1999

Life-cycle toxicity of bis(tributyltin) oxide to the sheepshead minnow (Cyprinodon variegatus).

The effects of tributyltin (TBT) to the life cycle of the estuarine fish Cyprinodon variegatus were examined in a 180-day flow-through exposure. The study was initiated with embryos less than 24 h postfertilization and monitored through hatch, maturation, growth, and reproduction under continuous exposure to mean measured TBT concentrations of 5.4, 3.2, 1.3, 0.66, and 0.41 microg TBT/L. Progeny isolated at the onset of reproduction by the parental generation (F0) were monitored for survival as embryos, survival as fry/juveniles, and growth 30 days postisolation. TBT, at a concentration of 5.4 microg/L, significantly reduced embryo survival of the F0 generation sheepshead minnows. By day 145 of the exposure, significant effects to the survival of this generation increased and included all test concentrations >/=0.66 microg/L. Survival of 0.66 microg/L was reduced 59% relative to control survival by termination of the F0 generation. Growth of F0 generation organisms as measured by standard length was significantly reduced only on day 90 at 3.2 microg/L, however no significant reductions of wet or dry weight related to treatment concentration were detected. Due to complete mortality of organisms exposed to 5.4 microg/L by study day 7, effects to fecundity and progeny were monitored at measured concentrations of 3.2, 1.3, 0.66, and 0.41 microg TBT/L. Fecundity, as measured by the production of viable eggs produced per female per day, was unaffected by any of the test treatments. All F1 generation embryos isolated from treatment chambers into 3.2 microg/L died. Survival, standard length, wet and dry weight of the F1 generation at the remaining treatment concentrations were unaffected. The results of this study indicate that exposure to TBT reduced survival of the F0 generation sheepshead minnow and establishes the lowest observed effect concentration (LOEC) as 0.66 microg TBT/L, and the no observed effect concentration (NOEC) as 0.41 microg TBT/L for this species.http://link.springer-ny. com/link/service/journals/00244/bibs/37n2p258.html

Aging↗