Generation Progeny Research Articles

Registration of Pearl Millet Genetic Male‐Sterile (ms3) Stock NM‐10H

A single plant exhibiting male sterility was discovered in a population of about 1000 plants of an F5 dwarf line 34‐2B, the maintainer line for cytoplasmic male sterile line 34‐2A4 of pearl millet [Pennisetum glaucum (L.) R. Br.]. Its cause was investigated using selfed and full‐sib progeny derived from crosses to different lines. Segregation ratios in these progeny showed that the sterility was due to a single recessive nuclear gene, ms3, the expression of which remained consistent across progeny generations both in field and greenhouse tests. Genetic stock NM‐10H (Reg. No. GS‐4, PI 664478) is an F5 line of pearl millet containing the genetic male sterility gene and was derived from a cross between the male sterility found in line 34‐2B and line 68B. The male sterility is maintained in a heterozygote (NM‐10H). The ms3 genetic male‐sterility gene may be useful in studying the effects of different cytoplasms on heterosis and other traits by using isonuclear hybrids and in histological studies on the development of male sterility in different types of male sterility.

Environmentally Induced Epigenetic Transgenerational Inheritance of Altered Sertoli Cell Transcriptome and Epigenome: Molecular Etiology of Male Infertility

Environmental toxicants have been shown to induce the epigenetic transgenerational inheritance of adult onset disease, including testis disease and male infertility. The current study was designed to determine the impact of an altered sperm epigenome on the subsequent development of an adult somatic cell (Sertoli cell) that influences the onset of a specific disease (male infertility). A gestating female rat (F0 generation) was exposed to the agriculture fungicide vinclozolin during gonadal sex determination and then the subsequent F3 generation progeny used for the isolation of Sertoli cells and assessment of testis disease. As previously observed, enhanced spermatogenic cell apoptosis was observed. The Sertoli cells provide the physical and nutritional support for the spermatogenic cells. Over 400 genes were differentially expressed in the F3 generation control versus vinclozolin lineage Sertoli cells. A number of specific cellular pathways were identified to be transgenerationally altered. One of the key metabolic processes affected was pyruvate/lactate production that is directly linked to spermatogenic cell viability. The Sertoli cell epigenome was also altered with over 100 promoter differential DNA methylation regions (DMR) modified. The genomic features and overlap with the sperm DMR were investigated. Observations demonstrate that the transgenerational sperm epigenetic alterations subsequently alters the development of a specific somatic cell (Sertoli cell) epigenome and transcriptome that correlates with adult onset disease (male infertility). The environmentally induced epigenetic transgenerational inheritance of testis disease appears to be a component of the molecular etiology of male infertility.

The 10 Most Read Articles Published in Circulation Research in 2012

The 10 Most Read Articles Published in <i>Circulation Research</i> in 2012

Trans-Generational Effects of Mild Heat Stress on the Life History Traits of an Aphid Parasitoid

Temperature changes are common in nature and insects are particularly exposed and sensitive to such variations which can be potential stresses, ultimately affecting life history traits and overall fitness. Braconids have been widely used to study the effects of temperature on host-parasitoid interactions and the present work focused on the solitary endoparasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae Aphidiidae), an efficient biological control agent commercially used against aphids such as the potato aphid Macrosiphum euphorbiae Thomas (Sternorrhyncha: Aphididae). Contrary to previous studies using heat shocks at extreme temperatures, we evaluated the effects of mild heat stresses by transferring young parasitoid adults from the constant temperature of 20°C to either a warm (25°C) or hot (28°C) temperature, for either 1 h or 48 h. Such treatments are consistent with situations commonly experienced by parasitoids when moved from their rearing conditions to greenhouses or field conditions. The effects were evaluated both on the heat stressed A. ervi adults (G0) (immediate effects) and on their first generation (G1) progeny (trans-generational effects). G0 wasps’ mortality was significantly affected by the temperature in interaction with the duration of the stress. Longevity of G0 wasps surviving the heat stress was negatively affected by the temperature and females lived longer than males. Heat stress applied to A. ervi parents also had consequences on their G1 progeny whose developmental time, rates of mummification and percentage of parasitoid completing total development were negatively affected. Surprisingly, the egg load at emergence of the G1 female progeny was increased when their mothers had been submitted to a mild heat stress of 25°C or 28°C. These results clearly demonstrate trans-generational phenotypic plasticity, showing that adaptation to thermal stresses may be achieved via maternal effects. This study also sheds light on the complexity of insect responses and underlying mechanisms to fluctuating conditions in their natural environment.

The Novelty of Human Cancer/Testis Antigen Encoding Genes in Evolution

In order to be inherited in progeny generations, novel genes should originate in germ cells. Here, we suggest that the testes may play a special “catalyst” role in the birth and evolution of new genes. Cancer/testis antigen encoding genes (CT genes) are predominantly expressed both in testes and in a variety of tumors. By the criteria of evolutionary novelty, the CT genes are, indeed, novel genes. We performed homology searches for sequences similar to human CT in various animals and established that most of the CT genes are either found in humans only or are relatively recent in their origin. A majority of all human CT genes originated during or after the origin of Eutheria. These results suggest relatively recent origin of human CT genes and align with the hypothesis of the special role of the testes in the evolution of the gene families.

Third generation evaluation of the Pacific oyster(Crassostrea gigas) breeding lines selected for fast growth

The Pacific oyster Crassostrea gigas,naturally occurring in Japan,China and Korea,is a major global aquaculture species. It is economically important and has had the highest worldw ide production in any cultured aquatic animal species since 1993. China produced over 3.5 million tons of cultured oysters,and C. gigas is one of the most important species. In view of the importance of this species,conventional selections have been carried out worldw ide in order to increase growth rate,and to improve survival. How ever,nearly all the broodstock of oyster used remains unselected in China. In order to improve the productivity traits of C. gigas,a selective breeding program for faster grow th was initiated in 2006. From 2007,successive generation of mass selection for fast grow th in shell height was conducted in three C. gigas stocks from China,Japan and Korea. The progeny of the third generation of the three C. gigas breeding lines( CS3,JS3, and KS3) were compared with the controls in a 420-day farming experiment. Mean shell height and mean total weight of the oysters from all three selection lines were significantly greater than those of controls(P0.05),respectively. At harvest on day 420,the increase in shell height for the three selection lines over the controls were 13.4%,10.1% and 10.5%,the increase in weight were 18.5%,13.4% and 11.6%. In the third generation of three C. gigas breeding lines,the realized heritability of shell height were 0.447±0.226, 0.471±0.297 and 0.367±0.167. In addition,the genetic gain of total weight for the CS3,JS3,and KS3 was 16.01%±3.82%,15.03%±5.21% and 11.57%±5.15%,respectively,demonstrating that total weight had been improved markedly during selection for shell height. These results indicate that the selection for fast growth achieved encouraging progress in the third generation of C. gigas breeding lines.

II. The effect of various doses of gamma 60Co radiation upon some morphological features of China aster (Callistephus chinesis Nees) in M1 and M2 generations

The present paper discusses the effect of antecedent gamma radiation upon 4 varieties of China aster in M&lt;sub&gt;1&lt;/sub&gt; and M&lt;sub&gt;2&lt;/sub&gt; generations. Studies were undertaken on the effect of various doses of radiation upon the following features : height of plants, maximal length of ramification of the Ist order, diameter of inflorescence, and number of set inflorescence. In M&lt;sub&gt;1&lt;/sub&gt; generation (plants from irradiated seeds) negative effect of radiation was noted in almost all features under study, usually the greater the radiation dose. Only in case of two varieties ('Agnieszka' and 'Goplana') positive effect of irradiation upon plant height was noted, at radiation dose of 3 kR. However, further increase of radiation dose was harmful also for these two varieties. In M&lt;sub&gt;2&lt;/sub&gt; generation (progeny of irradiated plants) the effect of gamma radiation upon most features under study was beneficial - in most cases stimulation overbalanced rare symptoms of depression. Reaction was different in all varieties under study.

Genetic Variability Studies in Induced Mutants of Sunflower (Helianthus annuus L.)

Abstract: An investigation was carried out to elicit information on genetic variability and for yield and its component traits in 34 mutants of Morden and 32 mutants of DSF 15B in M3 generation progenies of sunflower along with control. Most of the characters exhibited moderate to high variability. All the characters exhibited moderate to high heritability in mutants.

Genetic Analysis of Captive Spawning Strategies for the Endangered Rio Grande Silvery Minnow

Captive breeding and rearing are central elements in conservation, management, and recovery planning for many endangered species including Rio Grande Silvery Minnow, a North American freshwater cyprinid. Traditionally, the sole purpose of hatcheries was to produce as many fish as feasible for stocking and harvest. Production quotas are also an important consideration in hatchery programs for endangered species, but they must also maintain and maximize genetic diversity of fish produced through implementation of best breeding practices. Here, we assessed genetic outcomes and measures of productivity (number of eggs and larval viability) for three replicates of three mating designs that are used for this small, pelagic-spawning fish. These were 1) monogamous mating, 2) hormone-induced communal spawning, and 3) environmentally cued communal spawning. A total of 180 broodstock and 450 progeny were genotyped. Genetic diversity and egg productivity did not differ significantly among spawning designs (H e : F = 0.52, P = 0.67; H o : F = 0.12, P = 0.89; number of eggs: F = 3.59, P = 0.09), and there was evidence for variance in reproductive success among individuals in all three designs. Allelic richness declined from the broodstock to progeny generation in all breeding designs. There was no significant difference in the genetic effective size (regardless of the method used) among designs. Significantly more viable eggs were produced in environmentally cued communal spawn compared to the alternative strategies (F = 5.72, P = 0.04), but this strategy is the most difficult to implement.

Hormonal imprinting in the central nervous system: causes and consequences

The notion of the perinatal "hormonal imprinting" has been published at first in 1980 and since that time it spred expansively. The imprintig develops at the first encounter between the developing receptor and the target hormone - possibly by the alteration of the methylation pattern of DNA - and it is transmitted to the progeny generations of the cell. This is needed for the complete development of the receptor's binding capacity. However, molecules similar to the target hormone (hormone-analogues, drugs, chemicals, environmental pollutants) can also bind to the developing receptor, causing faulty imprinting with life-long consequences. This can promote pathological conditions. Later it was cleared that in other critical periods such as puberty, imprinting also can be provoked, even in any age in differentiating cells. The central nervous system (brain) also can be mistakenly imprinted, which durably influences the dopaminergic, serotonergic and noradrenergic system and this can be manifested - in animal experiments - in alterations of the sexual and social behavior. In our modern age the faulty hormonal imprintig is inavoidable because of the mass of medicaments, chemicals, the presence of hormone-like materials (e.g. soya phytosteroids) in the food, and environmental pollutants. The author especially emphasizes the danger of oxytocin, as a perinatal imprinter, as it is used very broadly and can basically influence the emotional and social spheres and the appearance of certain diseases such as auitism, schizophrenia and parkinsonism. The danger of perinatal imprinters is growing, considering their effects on the human evolution.

Effect of Entophytic Bacteria on the Rooting and Establishment of Cuttings of Hibiscus Rosasinensis

Any plants that are propagated vegetatively are likely to have an enduring community of bacterial colonists that are transferred in successive progeny generations. The plant growth promoting effects attributed to endophytes are due to the direct production of phytohormones such as auxins, cytokinins etc or through the induction of phytohormone synthesis by the plant. Being a vegetatively propagated plant species, Hibiscus rosasinensis shoots are amenable for treatment with endophytic bacteria. The effect of endophytic bacteria on the rooting and establishment of cuttings of Hibiscus rosasinensis was studied here. Four endophytic isolates and the consortium of them screened for their plant hormone production was used for this study. The treatment of cuttings with the tomato isolate LEE19 (Klebsiella sp.) for 12 hours, showed 75 % sprouting of cuttings and the highest shoot and root parameters compared to uninoculated cuttings. The rooting also increased to 100 % in LEE19 treatment. The treatment of entophytic bacteria increased significantly the number of leaves/ cutting, the shoot length, root length and fresh weight of roots. So the pre-plant stem treatment of cuttings can be recommended as a strategy for substituting or supplementing the use of chemical plant growth hormones in vegetative propagation of cuttings.

Laboratory Evaluation of Insecticidal Potentials of Kane Plant (Anogeissus leiocarpus Guil and Perr) for the Control of Bambara Groundnut Weevil (Callosobruchus subinnotatus Pic.) on Stored Bambara Groundnut ( Vigna subterranean (L.)Verdcourt)

Laboratory experiment was conducted during the year 2010 to evaluate the insecticidal potentials of different parts of Kane plant, Anogeissus leiocaipus Guil and Perri (leaves, stem and root barks), compare their efficacy with conventional insecticide (pirimiphos-methyl) and determine the concentration/rate that is effective in the control of damage caused by Bambara groundnut weevil, Callosobruchus subinnotatus Pic. on stored grains of Barn bar a ground nut (Vigna subterranae (L.) Verd.). The different parts of the plant materials were tested in powdered form at three different concentrations viz: 1, 3 and 5g/100g grain while the synthetic insecticide was applied at the recommended rate of 0.25g/100gseed. The experiment was laid out in a completely randomized design with each treatment replicated three times. The result shows that root bark at 1g/100g grain was the most effective in reducing oviposition (10.78) thereby bringing about a significant reduction in adult emergence (4.72), number of emergence holes (4.72), mortality (4.69) at 3 days after treatment (DAT) and grain damage (3 .07) while it competed favorably with the synthetic insecticide (pirimiphos-methyl). A significantly higher mortality of 2.89 and 2.89 in the first generation progeny was recorded in the leaf treated grains at 60 and 90 DAT, respectively. All the three different plant parts did not exhibit any significant negative effect on viability of the seeds tested. The stem bark and the leaves proved equal in efficacy to the root lark only at the highest rate/concentrations of 5g/100g grain. Based on the results of the experiments conducted, applications of the root bark of A. lelocarpus at the rate of 1- 5g/100g grain is recommended for an effective, cheap and safe protection of V. subterranean grains against damage caused by C. subinnotatus in storage.

Divergência genética entre acessos de batata-doce utilizando caracteres fenotípicos de raiz

Estudos de quantificação da divergência genética entre acessos e caracterização dos recursos genéticos têm sido de grande importância em programas de melhoramento, auxiliando na identificação de genitores e no conhecimento do material genético disponível. Os objetivos do presente trabalho foram: (1) avaliar os acessos de batata-doce pertencentes ao banco de germoplasma da Embrapa com base em caracteres de raiz; (2) calcular a importância relativa dos caracteres morfo-agronômicos quantitativos na discriminação dos acessos e, (3) obter indicações das combinações híbridas mais promissoras para cruzamentos. Foi avaliada uma coleção de 11 clones pertencentes ao Banco Ativo de Germoplasma da Embrapa por meio de um experimento conduzido na Embrapa SPM/EN, em Canoinhas-SC. Os acessos foram cultivados em condições de campo no delineamento em blocos ao acaso com quatro repetições, onde a parcela experimental foi composta por 10 plantas. As plantas de cada parcela foram colhidas e avaliadas para 12 caracteres fenotípicos de raiz. O estudo indicou que os caracteres número e massa total de raízes e peso específico foram os que mais contribuíram para a divergência genética. A maioria dos acessos é bastante similar quanto aos caracteres quantitativos avaliados. Porém, há a possibilidade de ganhos com a heterose, geração de variabilidade genética e de progênies superiores cruzando-se os acessos dos diferentes grupamentos formados; pois os genótipos mais contrastantes '1228', '051-1' e '1270' foram agrupados entre os melhores para várias características como massa e número total de raízes, massa comercial de raízes; os dois primeiros apresentaram elevado peso específico e o '1270' apresentou coloração alaranjada intensa, indicativo de alto teor de β-caroteno.

D471G Mutation in LCMV-NP Affects Its Ability to Self-associate and Results in a Dominant Negative Effect in Viral RNA Synthesis

Arenaviruses merit significant interest because several family members are etiological agents of severe hemorrhagic fevers, representing a major burden to public health. Currently, there are no FDA-licensed vaccines against arenaviruses and the only available antiviral therapy is limited to the use of ribavirin that is partially effective. Arenavirus nucleoprotein (NP) is found associated with the genomic RNA forming the viral ribonucleoproteins (vRNPs) that together with the polymerase (L) direct viral replication and transcription. Virion formation requires the recruitment of vRNPs into budding sites, a process in which the arenavirus matrix-like protein (Z) plays a major role. Therefore, proper NP-NP and NP-Z interactions are required for the generation of infectious progeny. In this work we demonstrate the role of the amino acid residue D471 in the self-association of lymphocytic choriomeningitis virus nucleoprotein (LCMV-NP). Amino acid substitutions at this position abrogate NP oligomerization, affecting its ability to mediate replication and transcription of a minigenome reporter plasmid. However, its ability to interact with the Z protein, counteract the cellular interferon response and bind to dsRNA analogs was retained. Additionally, we also document the dominant negative effect of D471G mutation on viral infection, suggesting that NP self-association is an excellent target for the development of new antivirals against arenaviruses.

Chlamydiae assemble a pathogen synapse to hijack the host endoplasmic reticulum.

Chlamydiae are obligate intracellular bacterial pathogens that replicate within a specialized membrane-bound compartment, termed an ‘inclusion’. The inclusion membrane is a critical host–pathogen interface, yet the extent of its interaction with cellular organelles and the origin of this membrane remain poorly defined. Here we show that the host endoplasmic reticulum (ER) is specifically recruited to the inclusion, and that key rough ER (rER) proteins are enriched on and translocated into the inclusion. rER recruitment is a Chlamydia-orchestrated process that occurs independently of host trafficking. Generation of infectious progeny requires an intact ER, since ER vacuolation early during infection stalls inclusion development, whereas disruption post ER recruitment bursts the inclusion. Electron tomography and immunolabelling of Chlamydia-infected cells reveal ‘pathogen synapses’ at which ordered arrays of chlamydial type III secretion complexes connect to the inclusion membrane only at rER contact sites. Our data show a supramolecular assembly involved in pathogen hijack of a key host organelle.

Resistance Development in Culex quinquefasciatus to Spinosad: A Preliminary Report

A Culex quinquefasciatus colony was established from surviving late instars and pupae from a semifield microcosm test with Natular XRG (a granular formulation containing 2.5% spinosad) applied at 14.2 kg/ha. The initial lethal concentrations for 50% and 90% of the population (LC50 and LC90) against Natular XRG were determined in the laboratory for the 1st generation progeny (F1). Selection was applied at LC70-90 levels to 10,000-15,000 of late 3rd and early 4th instars each generation. Susceptibility changes were determined every other generation and referenced to a susceptible laboratory colony as well as freshly collected wild populations of the same species concurrently. Tolerance to spinosad (resistance ratio < 5.0 fold) was observed up to F8 generation in the selected population. Thereafter, resistance ratios increased significantly from F10 to F16 generations, being 7.26- to 20.52-fold at the LC50 and 7.48- to 20.08-fold at the LC90 level.

Verification of epigenetic inheritance in a unicellular model system: multigenerational effects of hormonal imprinting

The unicellular Tetrahymena has receptors for hormones of higher vertebrates, produces these hormones, and their signal pathways are similar. The first encounter with a hormone in higher dose provokes the phenomenon of hormonal imprinting, by which the reaction of the cell is quantitatively modified. This modification is transmitted to the progeny generations. The duration of the single imprinter effect of two representative signal molecules, insulin and 5-HT (5-hydroxytryptamine), in two concentrations (10(-6) and 10(-15) M) were studied. The effects of imprinting were followed in 5 physiological indices: (i) insulin binding, (ii) 5-HT synthesis, (iii) swimming behaviour, (iv) cell growth and (v) chemotaxis in progeny generations 500 and 1000. The result of each index was different from the non-imprinted control functions, growth rate, swimming behaviour and chemotactic activity to insulin being enhanced, while others, e.g. synthesis and chemotactic responsiveness of 5-HT and the binding of insulin were reduced. This means that a function-specific heritable epigenetic change during imprinting occurs, and generally a single encounter with a femtomolar hormone concentration is enough for provoking durable and heritable imprinting in Tetrahymena. The experiments demonstrate the possibility of epigenetic effects at a unicellular level and call attention to the possibility that the character of unicellular organisms has changed through to the present day due to an enormous amount of non-physiological imprinter substances in their environment. The results - together with results obtained earlier in mammals - point to the validity of epigenetic imprinting effects throughout the animal world.

FGF signaling via MAPK is required early and improves Activin A-induced definitive endoderm formation from human embryonic stem cells

Considering their unlimited proliferation and pluripotency properties, human embryonic stem cells (hESCs) constitute a promising resource applicable for cell replacement therapy. To facilitate this clinical translation, it is critical to study and understand the early stage of hESCs differentiation wherein germ layers are defined. In this study, we examined the role of FGF signaling in Activin A-induced definitive endoderm (DE) differentiation in the absence of supplemented animal serum. We found that activated FGF/MAPK signaling is required at the early time point of Activin A-induced DE formation. In addition, FGF activation increased the number of DE cells compared to Activin A alone. These DE cells could further differentiate into PDX1 and NKX6.1 positive pancreatic progenitors in vitro. We conclude that Activin A combined with FGF/MAPK signaling efficiently induce DE cells in the absence of serum. These findings improve our understanding of human endoderm formation, and constitute a step forward in the generation of clinical grade hESCs progenies for cell therapy.

Imp2 controls oxidative phosphorylation and is crucial for preserving glioblastoma cancer stem cells

Growth of numerous cancer types is believed to be driven by a subpopulation of poorly differentiated cells, often referred to as cancer stem cells (CSCs), that have the capacity for self-renewal, tumor initiation, and generation of nontumorigenic progeny. Despite their potentially key role in tumor establishment and maintenance, the energy requirements of these cells and the mechanisms that regulate their energy production are unknown. Here, we show that the oncofetal insulin-like growth factor 2 mRNA-binding protein 2 (IMP2, IGF2BP2) regulates oxidative phosphorylation (OXPHOS) in primary glioblastoma (GBM) sphere cultures (gliomaspheres), an established in vitro model for CSC expansion. We demonstrate that IMP2 binds several mRNAs that encode mitochondrial respiratory chain complex subunits and that it interacts with complex I (NADH:ubiquinone oxidoreductase) proteins. Depletion of IMP2 in gliomaspheres decreases their oxygen consumption rate and both complex I and complex IV activity that results in impaired clonogenicity in vitro and tumorigenicity in vivo. Importantly, inhibition of OXPHOS but not of glycolysis abolishes GBM cell clonogenicity. Our observations suggest that gliomaspheres depend on OXPHOS for their energy production and survival and that IMP2 expression provides a key mechanism to ensure OXPHOS maintenance by delivering respiratory chain subunit-encoding mRNAs to mitochondria and contributing to complex I and complex IV assembly.

Does inbreeding promote evolutionary reduction of flower size? Experimental evidence from Crepis tectorum (Asteraceae)

Small, autogamous flowers have evolved repeatedly in the plant kingdom. While much attention has focused on the mechanisms that promote the shift to autogamy, there is still a paucity of information on the factors that underlie the reduction of flower size so prevalent in selfing lineages. In this study of Crepis tectorum, I examine the role of inbreeding, acting alone or together with selection, in promoting evolutionary reduction of flower size. Experimental crosses were performed to produce progeny populations that differed in inbreeding and (or) selection history. Progenies were grown in two different environments and scored for flower size and other characters. Inbreeding depressed flower and fruit size, but also caused changes in flowering time and the number of heads produced. Despite some inconsistencies in the results for the last progeny generation, the decline in flower size was persistent over generations, consistent across environments, and similar in magnitude to the effects of selection for small flower size and the floral reduction inferred to have taken place during the shift toward autogamy within the study species. The floral size reduction was largely independent of changes in overall vigor, and there was considerable adaptive potential in flower size (measured by sib analyses and parent-offspring comparisons) after inbreeding. The results of this study indicate that inbreeding can promote evolutionary reduction of flower size and highlight the close, persistent association between flower and fruit size in the study species.