Number Of Progeny Research Articles

Creation of elite growth and development features in PAP1-programmed red Nicotiana tabacum Xanthi via overexpression of synthetic geranyl pyrophosphate synthase genes

We report effects of overexpression of synthetic cDNAs encoding two forms of geranyl pyrophosphate synthase (GPPS) on growth and development performance of Production of Anthocyanin Pigment 1 (PAP1) gene-programmed tobacco (Nicotiana tabacum Xanthi) plants. Isogenic PAP1-programmed tobacco plants have a new trait that highly expresses anthocyanin biosynthetic pathway in all plant tissues, thus being considered a novel material for different studies. We recently used a homomeric Myzus persicae GPPS (MpGPPS) cDNA as a template to synthesize two new cDNA forms, sMpGPPS-HA and PTP-sMpGPPS-HA, which were designed to localize encoded proteins in the cytosol and plastids, respectively. One binary construct containing sMpGPPS-HA, the other binary construct containing PTP-sMpGPPS-HA, and another control construct were introduced to PAP1-programmed plants, respectively. Twenty to twenty-two T0 plants were generated for each construct. Seeds were collected from all plants to select T1 progeny with one single copy of the transgenes. Based on the Mendel law of inheritance, four T0 lines for each construct were identified to contain one single copy of transgene. A large number of T1 progeny from these T0 plants were selected for evaluation of plant development performance. The resulting data showed that the overexpression of each synthetic cDNA significantly enhanced fast growth, increased internodes and leaf numbers, increased leaf sizes, promoted earlier flowering, and approximately doubled plant biomass. This study indicates that a simultaneous enhancement of plant anthocyanin and terpenoid pathways creates novel elite PAP1-programmed plant varieties.

Selecting for Nut Characteristics in Macadamia Using a Genome-wide Association Study

Current macadamia breeding programs involve a lengthy and laborious two-stage selection process: evaluation of a large number of unreplicated seedling progeny, followed by replicated trials of clonally propagated elite seedlings. Yield component traits, such as nut-in-shell weight (NW), kernel weight (KW), and kernel recovery (KR) are commercially important, are more easily measured than yield, and have a higher heritability. A genome-wide association study (GWAS) combined with marker-assisted selection offers an opportunity to reduce the time of candidate evaluation. In this study, a total of 281 progeny from 32 families, and 18 of their 29 parents have been genotyped for 7126 single nucleotide polymorphism (SNP) markers. A GWAS was performed using ASReml with 4352 SNPs. We found five SNPs significantly associated with NW, nine with KW, and one with KR. Further, three of the top 10 markers for NW and KW were shared between the two traits. Future macadamia breeding could involve prescreening of individuals for desired traits using these significantly associated markers, with only predicted elite individuals continuing to the second stage of selection, thus potentially reducing the selection process by 7 years.

Population structure of Lori-Bakhtiari sheep in Iran by pedigree analysis

The objective of this study was to describe the population genetic structure and evaluate the state of conservation of genetic variability of Lori-Bakhtiari sheep in Iran. As such, pedigree information of 10,644 lambs lambed from 1989 through 2016 in the stud flock of Lori-Bakhttiari sheep was included in the analysis. Our first goal was to estimate mean and variance of family size across sires and dams using pedigree data. Our second goal was to estimate population structure in Lori-Bakhtiari sheep including estimation of pedigree completeness (PC), genetic conservation index (GCI), effective population size (Ne), effective number of founders (fe), effective number of ancestors (fa), generation interval (L), individual inbreeding coefficient (F) and average relatedness coefficient (AR) using the ENDOG software. The results showed that the average number of progenies per ram and ewe in their lifetime were 26.44 (15–152) and 3.6 (1–15), respectively. The mean and variance of family size of sires differ across years. The pedigree completeness (PC) was equal to 0.61. The fe and fa were 109 and 98, respectively with a ratio of 1.11. The number of ancestors explaining 50% of genetic diversity was 30. The Ne also varied from 142.68 to 144.13 during the study period. The average generation interval was 4.11 years. The mean inbreeding coefficient was 2.5% in inbred lambs and 1.26% in whole population with an annual increase of 0.09% per year and 0.87% per generation. The AR of the total population was estimated to 2.27% with an incremental trend of 0.10% per year and 0.59% in each generation. The average GCI was 11.75 units with an incremental trend of 0.76 per year. The effects of birth type and year of birth were found to be significant on most of the studied demographic parameters. Though there is an increasing inbreeding coefficient trend over a number of generations, it is still lower than the maximum acceptable recommendation of 1% per generation. This provides us an opportunity for maintaining genetic diversity and implementation of the improvement breeding program. However, unbalanced use of rams led to the creation of family size variation over years. Therefore, this study warrants a comprehensive mating plan with minimum inbreeding rate to maintain genetic variability in Lori-Bakhtiari sheep.

Reproductive success of a marine teleost was correlated with proactive and reactive stress-coping styles.

The present study investigated the relationship between reproductive success and stress-coping styles in gilthead seabream Sparus aurata in captivity. To characterise stress-coping styles, a total of 22 breeders were submitted to three different individual-based tests, one group-based test and post-handling glucocorticoid quantification. To assess spawning participation, a microsatellite analysis was performed on a total of 2698 larvae, which allowed each offspring to be assigned unambiguously to a single parental couple. Overall, S. aurata showed defined proactive and reactive behavioural traits. Proactive breeders exhibited higher levels of activity and risk taking and lower glucocorticoid blood levels than reactive breeders. The stress-coping style traits were consistent over time and context (different tests). Breeders that contributed to a higher number of progeny exhibited proactive behaviours, while those showing low progeny contribution exhibited reactive behaviour. Therefore, breeders with a high proportion of progeny (> 20%) had significantly higher activity and risk taking and lower cortisol than breeders with low progeny contribution (< 20%). In addition, males were more proactive than females and males exhibited significantly higher activity, risk taking and lower cortisol than females. This study is the first to establish in S. aurata breeders: (a) a relationship between stress-coping styles and spawning success; (b) a relationship between stress-coping styles and gender; and (c) the existence of proactive and reactive traits at the adult stage.

Intergenerational reproductive toxicity of chlordecone in male Caenorhabditis elegans.

Chlordecone (CLD), also named Kepone, is a synthetic organochlorine pesticide. As one of the common persistent organic pollutants (POPs) in nature, CLD has a profound impact on the environment and human health. The study aims to investigate the reproductive toxicity effects of CLD on male Caenorhabditis elegans and on progeny. L1-stage male nematodes were exposed to the control group (M9 solution) and four dose groups (0.02, 0.2, 2, and 20μg/L). After exposure for 48h, the male nematodes were picked to mating experiment and progeny experiment that the number of progeny and the time of observation in male parent and in F1 generation were counted; the number of germ cells and the number of sperm in the meiotic division of male nematodes were counted by staining with dimercaptophenyl hydrazine (DAPI), and the nematode gland area was observed under the bright field of the microscope. In male nematodes, the results showed that a number of progeny were 351.20 ± 31.40, 321.60 ± 24.70, 307.30 ± 19.30, 240.10 ± 27.60, and 227.90 ± 22.70 (P < 0.05); the generation times were 55.80 ± 1.95h, 56.40 ± 1.60h, 56.70 ± 0.92h, 60.80 ± 0.95h, and 69.60 ± 1.97h (P < 0.05); relative areas of gonad were (99.80 ± 6.27)%, (93.00 ± 1.70)%, (85.00 ± 1.70)%, (70.70 ± 9.81)%, and (60.00 ± 5.23)% (P < 0.05); DAPI staining results showed the number of germ cells in meiosis area were 191.00 ± 10.97, 181.10 ± 15.56, 177.00 ± 9.20, 147.50 ± 10.56, and 139.30 ± 23.79 (P < 0.05); the sperm numbers were 335.60 ± 21.31, 308.60 ± 19.60, 306.00 ± 11.23, 260.10 ± 27.41, and 255.00 ± 3.72 (P < 0.05). In the F1 generation, the progeny numbers were 328.10 ± 22.28, 167.50 ± 15.30, 150.00 ± 13.65, 131.30 ± 18.40, and 130.20 ± 16.17 (P < 0.05); the generation times were 55.50 ± 2.36, 71.10 ± 0.97, 70.90 ± 0.52, 74.10 ± 2.07, and 73.90 ± 1.35h (P < 0.05). The groups are grouped in order as M9 solution, 0.02, 0.2, 2, and 20μg/L. The results revealed that CLD caused decrease in progeny number, relative area of gonad, number of germ cells, and sperm number and prolonged the generation time in the male nematode. In offspring grown up without CLD, the effect of CLD on generation time and sperm number can still be observed on offspring. In conclusion, CLD induces male nematode reproductive toxicity and causes defects in offspring.

Towards development of a parasitoid cottage industry of the parasitoid wasp Habrobracon hebetor (say): optimum rearing and releases conditions for successful biological control of the millet head miner Heliocheilus albipunctella (De Joannis) in the Sahel

Augmentative biological control by the parasitoid Habrobracon hebetor (Say) (Hymenoptera: Braconidae) is the most promising strategy to control millet head miner, Heliocheilus albipunctella (De Joannis) a major insect pest of pearl millet in the Sahel. As H. hebetor survival is somehow challenging during the nine month long off-season when the host, H. albipunctella is in diapause, there needs to be a sufficient supply of parasitoids for fresh release each year. Therefore, the aim of this study was to establish a small-scale parasitoid rearing process adjusted to the Sahel conditions that can be scaled-up as necessary. We conducted experiments to fine-tune and standardize the rearing technique of H. hebetor for cottage industrial use. The results showed that parasitoids fed with 30% honey solution and supplied daily with one late-larval-stage Corcyra cephalonica Stainton (Lepidotera, Pyralidae) produced highest number of progeny. The optimal times for mating and egg fertilization, was achieved when a male and female pair was confined for 24 h in a 30-cc vial. Our findings indicated that, compared with the conventional rearing method -2 females supplied once with 25 C. cephalonica larvae-, this new method resulted in 14-times greater parasitoid production. Furthermore parasitoid female can be stored for up to three weeks at fluctuating 23–32°C temperature and 25%–80% relative humidity for numbers accumulations prior to on-farm augmentative releases without altering its fitness.

In vivo Toxicity Assessment of Silver Nanoparticles in Homeostatic versus Regenerating Planarians

Silver nanoparticles (AgNPs) belong to the most commercialized nanomaterials, used in both consumer products and medical applications. Despite its omnipresence, in-depth knowledge on the potential toxicity of nanosilver is still lacking, especially for developing organisms. Research on vertebrates is limited due to ethical concerns, and planarians are an ideal invertebrate model to study the effects of AgNPs on stem cells and developing tissues in vivo, as regeneration mimics development by triggering massive stem cell proliferation. Our results revealed a strong interference of AgNPs with tissue- and neuroregeneration which was related to an altered stem cell cycle. The presence of a PVP-coating significantly influenced toxicity outcomes, leading to elevated DNA-damage and decreased stem cell proliferation. Non-coated AgNPs had an inhibiting effect on stem cell and early progeny numbers. Overall, regenerating tissues were more sensitive to AgNP toxicity, and careful handling and appropriate decision making is needed in AgNP applications for healing and developing tissues. We emphasize on the importance of AgNP characterization, as we showed that changes in physicochemical properties influence toxicity.

Influence of Density on Interspecific Competition Between Spathius galinae (Hymenoptera: Braconidae) and Tetrastichus planipennisi (Hymenoptera: Eulophidae), Larval Parasitoids of the Invasive Emerald Ash Borer (Coleoptera: Buprestidae).

The outcomes of interspecific interactions between parasitoids depend on a variety of factors. Understanding the influence of these factors is important for classical biological control, where the success of parasitoid releases partly depends on interactions with native and other introduced species. However, results from laboratory experiments may not always reflect those in the field, as densities may be artificially inflated. To mitigate this problem, we examined the effects of multiple densities on interspecific competition between two larval parasitoids of emerald ash borer (Agrilus planipennis Fairmaire): Spathius galinae Belokobylskij and Tetrastichus planipennisi Yang. Parasitoid species were housed individually or together at two different densities, and we measured the effects on percent parasitism and progeny production, before calculating the interaction strengths. We found no significant effects of parasitoid density on percent parasitism, but the effect of competition on parasitism generally was reduced at lower densities. However, there were significant differences in parasitism by species, with S. galinae parasitizing more larvae than T. planipennisi. There were also no significant effects of parasitoid density on the number of progeny produced by each species, though the effect of competition on progeny production was greater at higher densities. Similarly, though, there were significant differences between species in the number of progeny produced. Specifically, T. planipennisi consistently produced larger broods than S. galinae. Our findings complement existing research suggesting that competition between these two species in the field will likely be negligible.

Assessment of Rhyzopertha dominica (F.) progeny and feeding damage on rice dried with infrared radiation

Infrared radiation (IR) is a method of drying grains that eliminates insect and microbial pests. It is unknown if IR could cause grains to be more susceptible to insects. Thus, the effects of IR on Rhyzopertha dominica development and feeding damage using long-grain rice varieties, Clearfield XL745 (hybrid) and CL152 (pureline), were examined. Rough rice was dried with three IR intensities: 2.15, 2.83, and 10.84 kW/m2. The number of progeny developed, feeding damage, and frass weight after IR-drying were compared with air-drying methods for rough rice and rice milled to brown rice after drying. Since R. dominica develop internally, X-ray technology was used to examine internal progeny and feeding damage. Progeny development and kernel damage appeared to be more affected by fraction (brown rice) than the cultivar of rice or intensity of IR used, with more progeny produced on brown rice than rough rice. An IR intensity of 10.84 kW/m2 increased the number of overall progeny, the amount of adults, and frass produced on CL152 brown rice. An intensity of 10.84 kW/m2 also increased the amount of larvae observed for both varieties and fractions. The intensity of 10.84 kW/m2, under the conditions of this study, is not recommended for drying rice.

Susceptibility of selected maize seed genotypes to Sitophilus zeamais (Coleoptera: Curculionidae)

Studies were carried out under laboratory conditions of 25 ± 2 °C and 70 ± 5% RH in an incubator to determine the relative susceptibility of eighteen maize genotypes to attack by the maize weevil, Sitophilus zeamais Motschulsky. The experiment was laid out in a Completely Randomized Design (CRD) with three replications. Adult mortality, number of F1 progeny, weevil development time, susceptibility index, percentage seed damage, percentage weight loss, and weight of powder produced were determined after storage period of three months. The susceptibility index was determined using Dobie’s formula and the genotypes were classified into different susceptibility groups. The genotypes exhibited varying degrees of susceptibility to S. zeamais attack. Only Aseda was regarded as resistant and TZE-Y POP STR as moderately resistant to S. zeamais. Kpari-Faako, Tintim, WACCI-M-1215, WACCI-M-1594 and Wang-Dataa were regarded as moderately susceptible to S. zeamais. However, Abontem, Bihilifa, Ewul-Boyu, Sanzal-Sima, TZE-I 17, WACCI-M-1205, WACCI-M-1508 and WACCI-M-1510 were regarded as susceptible genotypes. Furthermore, Aburohemaa, Obaatanpa and Omankwa were regarded as highly susceptible to S. zeamais. Number of F1 progeny, seed damage, seed weight loss, weight of dust produced and seed moisture content had positive relationship with varietal susceptibility while adult weevil mortality, median development period and seed germination after infestation had an inverse relationship with susceptibility in maize. The use of insect resistant genotypes would offer a sustainable way of minimizing postharvest losses of seeds in storage especially for smallholder farmers who keep harvested grains for future use as food and seed.

How accurately do behavioural observations predict reproductive success in free-ranging lizards?

Behavioural ecologists often use data on patterns of male–female association to infer reproductive success of free-ranging animals. For example, a male seen with several females during the mating season is predicted to father more offspring than a male not seen with any females. We explored the putative correlation between this behaviour and actual paternity (as revealed by microsatellite data) from a long-term study on sand lizards (Lacerta agilis), including behavioural observations of 574 adult males and 289 adult females, and paternity assignment of more than 2500 offspring during 1998–2007. The number of males that contributed paternity to a female's clutch was correlated with the number of males seen accompanying her in the field, but not with the number of copulation scars on her body. The number of females that a male accompanied in the field predicted the number of females with whom he fathered offspring, and his annual reproductive success (number of progeny). Although behavioural data explained less than one-third of total variance in reproductive success, our analysis supports the utility of behavioural-ecology studies for predicting paternity in free-ranging reptiles.

Genetic gain of Al tolerance and contribution of agronomic traits on Al tolerance in the early stage of sorghum breeding program

ABSTRACT Genetic gain (GG), heritability and contribution of the agronomic traits on Al tolerance are precious information for selection strategy in the breeding of Al-tolerant sorghum. The objectives of this study were (i) to estimate the GG of Al tolerance in sorghum and (ii) to determine the direct effect of agronomic traits on Al tolerance through path analysis. Evaluation of agronomic characters used F2, and F3 sorghum progenies in field experiment and screening of Al tolerance used the hematoxylin-staining method. Three sorghum populations showed the low GG of Al tolerance (GG = 0.558–1.108). This result indicates that high allocation of progenies in the early stages of the Al-tolerant breeding program and high selection differential (sd) of Al tolerance should be applied to obtain a higher gain of Al tolerance. Selection pressure for early maturity (sd = −2.942) and short plant height (PH) (sd = −38.165) resulted in lower improvement of GG for Al tolerance. The high dry weight and tall PH provided a more genetic contribution to the advancement of Al tolerance. Based on the overall path analysis data, the increase of plant biomass, the significant number of progenies in the early stage of breeding and strong sd of Al tolerance would be more appropriate to improve the Al tolerance in sorghum.

Inferring Demography and Selection in Organisms Characterized by Skewed Offspring Distributions.

The recent increase in time-series population genomic data from experimental, natural, and ancient populations has been accompanied by a promising growth in methodologies for inferring demographic and selective parameters from such data. However, these methods have largely presumed that the populations of interest are well-described by the Kingman coalescent. In reality, many groups of organisms, including viruses, marine organisms, and some plants, protists, and fungi, typified by high variance in progeny number, may be best characterized by multiple-merger coalescent models. Estimation of population genetic parameters under Wright-Fisher assumptions for these organisms may thus be prone to serious mis-inference. We propose a novel method for the joint inference of demography and selection under the Ψ-coalescent model, termed Multiple-Merger Coalescent Approximate Bayesian Computation, or MMC-ABC. We first demonstrate mis-inference under the Kingman, and then exhibit the superior performance of MMC-ABC under conditions of skewed offspring distributions. In order to highlight the utility of this approach, we reanalyzed previously published drug-selection lines of influenza A virus. We jointly inferred the extent of progeny-skew inherent to viral replication and identified putative drug-resistance mutations.

Auxin application in interploidy crosses and genome stability: across-generation investigations on German chamomile (Matricaria recutita [L.] Rauschert) of various origins

Interploid crosses display a common approach in plant breeding to vary ploidy level in crops. This research included three trials to determine ploidy purity and genomic stability of diploid, triploid and auto-tetraploid varieties of German chamomile during life-time and across generations after interploid crosses. Impacts of auxin application were evaluated for seed set, germination rate and progeny ploidy. Ploidy was assessed by flow cytometry and chromosome counting. Ploidy purity in cultivars ranged from 64% (‘Lutea’, 4x) to 100% (‘Bona’, 2x), the share of ploidy-deviants was in 4x-cultivars higher (8%) than in 2x (1%). Auxin application resulted in higher seed set in tetraploids only, while the number of progeny did neither depend on cross direction nor on auxin application. Life time genome stability applied for all ploidy levels. Ploidy level of progeny from 2x × 4x crosses was mostly linked to the maternal level. 3x plants bore progeny with diverse ploidy forms, but not with triploidy. However, cultivars should regularly be monitored for conformance to declared ploidy also in awareness of possible unintended contamination.

Intracellular Interactions in the Reproduction Control of Introgressed Strains Involving Species from &amp;lt;i&amp;gt;Drosophila saltans&amp;lt;/i&amp;gt; Group (&amp;lt;i&amp;gt;Sophophora Subgenus&amp;lt;/i&amp;gt;) with Emphasis to the Effect of &amp;lt;i&amp;gt;Wolbachia&amp;lt;/i&amp;gt; Infection

Interspecific hybrids and constructed research models have provided infor-mation on intracellular interactions. We used two introgressed, chromosomally differentiated strains (H4 and H2) derived from F1 hybrids of crosses between D. prosaltans females and D. saltans males. In H4, the D. prosaltans chromosomes were eliminated. In H2, a mixture was maintained, preserving the entire genome of D. prosaltans (except the Y chromosome) and parts of the D. saltans genome. The IIR arm and a segment of chromosome III were eliminated. A third strain, used for comparison, was a normal D. prosaltans strain (P). This study aimed primarily to analyze the effect on the reproductive char-acteristics productivity (number of progeny) and sex-ratio caused by Wolbachia infection in interaction with different chromosome constitutions. For this, infected and uninfected flies were used in intrastrain cross combinations. Firstly, we analyzed the productivity of intracrosses of uninfected parents, in each strain, in order to detect the effects of intracellular interactions, in flies carrying different chromosome constitutions and sharing a Wolbach-ia-free, D. prosaltans cytoplasm. Data indicated that the chromosome parts that were eliminated, in H2, carry the isolating genes that impair productivity in hybrids of the two species, and suggested the occurrence of a nuclear/nuclear interaction. The analysis of Wolbachia-infected flies showed that the three strains presented different responses, depending on the chromosome constitution. As to productivity, the infection was harmful in P strain, in H2 behaved as mutualistic, and, in H4, produced the effect cytoplasmic incompatibility. As to sex-ratio, intracrosses showed significant differences in P and H4 strains. These results, associated with the cytological characteristics of the strains, pointed to the fundamental importance of host chromosome constitution to define the interactive process host/Wolbachia, and showed the flexibility of the endo-symbiont manifested in different forms of self-preservation.

A Strategy To Exploit Surrogate Sire Technology in Livestock Breeding Programs.

In this work, we performed simulations to develop and test a strategy for exploiting surrogate sire technology in animal breeding programs. Surrogate sire technology allows the creation of males that lack their own germline cells, but have transplanted spermatogonial stem cells from donor males. With this technology, a single elite male donor could give rise to huge numbers of progeny, potentially as much as all the production animals in a particular time period. One hundred replicates of various scenarios were performed. Scenarios followed a common overall structure but differed in the strategy used to identify elite donors and how these donors were used in the product development part. The results of this study showed that using surrogate sire technology would significantly increase the genetic merit of commercial sires, by as much as 6.5 to 9.2 years’ worth of genetic gain compared to a conventional breeding program. The simulations suggested that a strategy involving three stages (an initial genomic test followed by two subsequent progeny tests) was the most effective of all the strategies tested. The use of one or a handful of elite donors to generate the production animals would be very different to current practice. While the results demonstrate the great potential of surrogate sire technology there are considerable risks but also other opportunities. Practical implementation of surrogate sire technology would need to account for these.

Effect of avocado and yogurt in diet media on wing length, ovariole number and progeny production of Drosophila melanogaster

Dietary constituents are known to have profound effect on physiological activities including reproductive fitness, fecundity and body size of the organism. In the present study, the flies of Drosophila melanogaster were reared in yogurt and avocado supplemented media to understand its effect on the wing length, ovariole number and progeny production. The results showed that the wing length, ovariole number and progeny production were significantly higher in those reared on avocado+ yogurt media followed by yogurt supplemented media. This suggests that avocado and yogurt as a combination followed by yogurt alone provided required nutrients to the flies to grow larger in size and have a greater number of ovarioles, and produce greater number of progeny than the flies grown in wheat-cream agar media. These results suggest that avocado and yogurt as a combination provide reproductive fitness benefits followed by yogurt media alone.

Heritability of ram mating success in multi-sire breeding situations

Multi-sire mating of a mob of ewes is commonly used in commercial sheep production systems. However, ram mating success (defined as the number of lambs sired by an individual) can vary between rams in the mating group. If this trait was repeatable and heritable, selection of rams capable of siring larger numbers of lambs could reduce the number of rams required for mating and ultimately lead to increased genetic gain. However, genetic correlations with other productive traits, such as growth and female fertility, could influence the potential for ram mating success to be used as a selection trait. In order to investigate this trait, parentage records (including accuracy of sire assignment) from 15 commercial ram breeding flocks of various breeds were utilised to examine the repeatability and heritability of ram mating success in multi-sire mating groups. In addition, genetic and phenotypic correlations with growth and female fertility traits were estimated using ASReml. The final model used for the ram mating success traits included age of the ram and mating group as fixed effects. Older rams (3+years old) had 15% to 20% greater mating success than younger rams (1 or 2 years of age). Increasing the stringency of the criteria for inclusion of both an individual lamb, based on accuracy of sire assignment, or a whole mating group, based on how many lambs had an assigned sire, increased repeatability and heritability estimates of the ram mating success traits examined. With the most stringent criteria employed, where assignment of sire accuracy was >0.95 and the total number of lambs in the progeny group that failed to have a sire assigned was<0.05, repeatability and heritability for loge(number of lambs) was 0.40±0.09 and 0.26±0.12, respectively. For proportion of lambs sired, repeatability and heritability were both 0.30±0.09. The two ram mating traits (loge(nlamb) and proportion) were highly correlated, both phenotypically and genetically (0.88±0.01 and 0.94±0.06, respectively). Both phenotypic and genetic correlations between ram mating success and growth and other female fertility traits were low and non-significant. In conclusion, there is scope to select rams capable of producing high numbers of progeny and thus increase selection pressure on rams to increase genetic gain.

Generation of Neural Stem Cells from Induced Pluripotent Stem Cells.

Neural stem cells (NSCs) are defined by three necessary but not sufficient criteria: (1) self-renewable, (2) ability to generate a large number of progeny, and (3) ability to differentiate into the principal central nervous system (CNS) cell types, neurons, astrocytes, and oligodendrocytes. There are various approaches to derive neural lineages from pluripotent stem cells. It is well recognized that the chosen method of NSC derivation is critical to answering the basic biology question under investigation, to the success rate in drug discovery and to the efficacy of the therapeutic cells intended for repairing the CNS. There are three critical attributes of NSCs: (1) well-defined and stable cellular composition, (2) consistent process of perpetuation that avoids drift in composition, and (3) stable phenotype or therapeutic activity of the NSCs or their differentiated progeny. Over the past decades, we have been continuously developing consistent processes for generating stable, multipotent self-renewable NSCs from various sources. In this chapter, we report a method to generate NSCs from induced pluripotent stem cells.

Behavioral and biological responses of black bean aphid (Aphis fabae, Scopoli, 1763) on seven Algerian local broad bean cultivars

We studied the behavioral and biological parameters of Aphis fabae (Homoptera: Aphididae, Scopoli, 1763) on seven local Vicia faba L. cultivars. The antixenosis was conducted under laboratory controlled conditions of the temperature, light regime and relative humidity (18 ± 0.25 °C; L16: D8; 37.5 ± 0.6 %) for test in light, and (19 °C; 42 % relative humidity) for test in dark. The least preferred host plants for attractivity was the cultivar 141 in both tests while the cultivar 145 was the most preferred in light test, and the cultivar 107 in dark test. The antibiotic experiment was conducted also under laboratory conditions (L16: D8 photoperiod, 17 ± 1 °C, and 43.5 ± 5 % r. h.). Antibiosis was determined by studying the pre-reproductive period, reproductive period, adult longevity, survival, daily and total fecundity. The analysis of variance indicated that no significant differences on pre-reproductive period and daily fecundity of the A. fabae among the cultivars. However, the longest times of reproductive period, adult longevity, and survival were recorded on cultivar 135 followed by cultivar 141. The highest (85.8) and the lowest (15.8) number of progeny were observed on 135 and 141 cultivars, respectively.