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Parental Generation (parental + generation)
Selected AbstractsAncestral feeding and survival of offspring in European corn borerENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2002D.A. Andow Abstract Experiments were conducted to evaluate the influence of ancestral adult feeding by European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), on larval survival in the field and neonate movement behavior in laboratory. Larval survival was higher when either the grandparental or parental generation had fed, but the feeding sites of the surviving larvae were not affected by ancestral feeding condition. This is the first evidence that grandparental feeding could influence larval survival in the field. Larval movement was observed in the laboratory. Silking speed of neonates was faster when either grandparents or parents had fed, while walking speed was faster only when parents had fed. No broad-sense genetic correlation was found between silking speed and walking speed. Broad-sense heritability among feeding histories were not significant for silking speed, but was significantly greater than zero for walking speed when grandparents fed and parents did not. These intergenerational effects could induce complex population dynamics in this species. [source] Estrogenic compounds affect development of harpacticoid copepod Tigriopus japonicusENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2003Helen S. Marcial Abstract The aim of this investigation was to evaluate the impact of estrogenic compounds onthe harpacticoid copepod Tigriopus japonicus after continuous exposure to environmentally relevant concentrations. Natural estrogen (17,-estradiol), three known estrogenic compounds in vertebrates (bisphenol A, 4-nonylphenol, p - t -octylphenol), and an invertebrate molting hormone (20-hydroxyecdysone) were tested for their effects on development and reproductive characters in two successive generations of T. japonicus. Less than 24-h-old nauplii (parentals) were exposed to four sublethal concentrations of these compounds for 21 d at 25°C. The first brood of nauplii (F1) produced was monitored further under the same culture conditions and exposures to test compounds. Results showed that all estrogenic compounds affected development (both in number of days to reach copepodid stage and sexual maturity) in the parental generation. Similar effects were apparent in the F1; however, fecundity, sex ratio, and survival were not significantly affected, even at concentrations as high as 10 ,g/L (nominal concentration). The invertebrate molting hormone 20-hyroxyecdysone had no detectable effect on any of the endpoints tested but gave the lowest 48-h 50% lethal concentration (LC50) value. The results suggest that endocrine disruption could occur in copepods following exposure to environmentally relevant concentrations of estrogenic compounds, especially if they are exposed starting from embryonic development. [source] Growth of functional cranial components in rats submitted to intergenerational undernutritionJOURNAL OF ANATOMY, Issue 2 2006María F. Cesani Abstract The aim of the present study was to discover how intergenerational undernutrition affects the growth of major and minor functional cranial components in two generations of rats. Control animals constituted the parental generation (P). The undernourished generations (F1 and F2) were fed 75% of the control diet. Animals were X-rayed every 10 days from 20 to 100 days of age. The length, width and height of the major (neurocranium and splanchnocranium) and minor (anterior-neural, middle-neural, posterior-neural, otic, respiratory, masticatory and alveolar) cranial components were measured on each radiograph. Volumetric indices were calculated to estimate size variations of these components. Data were processed using the Kruskal,Wallis and Kolmogorov,Smirnov tests for two samples. Impairment in splanchnocranial and neurocranial growth was found, the latter being more affected than the former in F1. Comparison between F2 and F1 animals showed cumulative effects of undernutrition in both major and minor components (anterior-neural, respiratory, masticatory and alveolar in males, and middle-neural and respiratory in females). Such differential effects on minor components may reflect a residual mechanical strain resulting from the linkage between components. This phenomenon was clearly observed in the neurocranium and could be understood as an adaptive response to the demands of the associated functional matrices. [source] Potential for controlling codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) in Argentina using the sterile insect technique and egg parasitoidsJOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2010E. Botto Abstract Codling moth is the main pest affecting apples and pears worldwide. Most pest control strategies used against this insect have relied on the use of broad-spectrum insecticides which have led to non-desirable effects like pesticide resistance, residues in the environment, human health concerns and the reduction of access to international markets. Therefore, alternative pest control strategies that would result in sustainable fruit production systems while taking care of the environment are strongly promoted. The use of the sterile insect technique has proven to be a valuable pest control tactic within area-wide integrated pest management strategies, and its synergistic effect for Lepidoptera pests when combined with other biological control tactics such as parasitoids has been documented. The purposes of this research were to evaluate the response of an Argentinean codling moth strain to a sub-sterilizing radiation dose of 100 Gy and to assess the acceptability and suitability of sterile codling moth eggs by the egg parasitoids, Trichogramma cacoeciae (Marchal) and Trichogramma nerudai (Pintureau and Gerding). Irradiated female moths survived better than irradiated male moths and non-irradiated male and female moths. Also, the fecundity of irradiated female moths was reduced by more than 30% as compared to non-irradiated ones whereas their fertility was close to zero. The F1 generation was male biased with a lower fertility (inherited sterility) than the parental generation. Trichogramma cacoeciae and T. nerudai parasitized both fertile and sterile eggs. However, there was a significant reduction in acceptability for sterile eggs. Trichogramma nerudai parasitized more eggs than T. cacoeciae, but egg acceptability for this species was proportionally lower than for T. cacoeciae especially on eggs oviposited by irradiated females. Development to adult of both parasitoids species was not substantially affected by the origin of the eggs and the wasps had acceptable levels of adult emergence, survival and fecundity. These results provided useful information on the potential for controlling the codling moth using egg parasitoids and the sterile insect technique in Argentina. [source] Altitudinal variation in behavioural thermoregulation: local adaptation vs. plasticity in California grasshoppersJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2005J. SAMIETZ Abstract We investigated the adaptive significance of behavioural thermoregulation in univoltine populations of the grasshopper Melanoplus sanguinipes along an altitudinal gradient in California using laboratory tests of animals raised under different temperatures. Trials consisted of continuous body temperature measurements with semi-implanted microprobes in a test arena, and observation and simultaneous recording of behavioural responses. These responses included mobility, basking and orientation of the body axes (aspect angle) towards a radiation source. Mobility and basking are determined by the altitudinal origin of the parental generation and not by the temperature treatments. With increasing altitude, individuals tend increasingly to raise body temperatures via mobility and increased basking. In contrast, body orientation towards the radiation source is influenced by the temperature treatments but not by the altitude of origin. Individuals experiencing higher temperatures during rearing show a lower tendency to lateral flanking. We conclude that body orientation responses are not adapted locally. In contrast other components of the behavioural syndrome that increase body temperature, such as mobility and basking, are adaptive in response to local selection pressure. The thermoregulatory syndrome of these grasshoppers is an important contribution to life-history adaptations that appropriately match season lengths. [source] TIMP-1 as candidate gene for embryo survival in two divergent lines selected for uterine capacity in rabbits,MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 6 2006Jordi Estellé Abstract Selection on uterine capacity has been used in animal breeding as a way to improve the litter size. A divergent selection experiment for uterine capacity was performed in rabbits during ten generations. After the first generations of selection, large differences in number of implanted embryos were obtained between high and low lines. The major part of the differences between lines was due to embryo survival. A segregation analysis suggested the presence of a major gene affecting the reproductive traits. The objective of this work was to test the TIMP-1 gene as a candidate gene for embryo survival in rabbits since it stands up as a target for the investigation of reproductive problems in humans. We have analyzed the parental generation of a F2 cross which consists of 8 and 14 animals from the high and low uterine capacity lines, respectively. The rabbit TIMP-1 gene structure and sequence has been determined, including the proximal promoter region. Despite of the absence of polymorphism between lines in the screened regions (CDS, proximal promoter, exon 1, intron 1, and exon 2), a real-time RT-PCR quantification of the TIMP-1 mRNA in oviduct has shown significant differences between high and low lines at 62 hr of gestation, just when rabbit embryos are located in the oviduct, postulating TIMP-1 as an interesting candidate gene to be involved in the phenotypic differences between the two rabbit lines. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source] Gamma radiation sensitivity of the eggs, larvae and pupae of Indian meal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2008Abdurrahman Ayvaz Abstract BACKGROUND: This study focused on determining the minimal effective gamma radiation dose that prevents commodity damage caused by the Indian meal moth Plodia interpunctella (Hübner). The study was also designed to assess the effect of releasing either partially sterilized males alone or both partially sterilized males and females on the reproductive potential of P. interpunctella populations. RESULTS: The dose of radiation required to prevent larval emergence from irradiated eggs was 350 Gy, and the same dose was also required to prevent adult emergence from mature larvae. A dose of 300 Gy was not able to prevent adult emergence from irradiated pupae. The dose at which 100% sterility was achieved in treated females mated to treated males was 300 Gy for the parental generation of irradiated pupae. Fertility of the parental males from irradiated pupae was 48.17% at 300 Gy in treated males crossed with untreated females, but male progeny of irradiated male parents had a residual fertility of 11.06% at the same dose. CONCLUSION: F1 males from irradiated pupae were more sterile than parental males. To prevent larval emergence from irradiated eggs, a dose of 350 Gy is required. The same dose is required to prevent the larvae from reaching the adult stage. Copyright © 2008 Society of Chemical Industry [source] Study of anticipation in Chinese families with schizophreniaPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 2 2001Ching-Hua Lin MD Abstract The anticipation phenomenon is an important aspect in several genetic disorders in which the age at onset (AAO) decreases and the severity of illness increases in successive generations. This phenomenon has been reported in several schizophrenic family studies, and expanded repeat mutations are implicated. In the present study, we investigate the anticipation phenomenon in Chinese schizophrenic families. We compare the AAO between two generations of 38 unilinear schizophrenic families. Intergenerational comparisons show that the AAO was significantly earlier in the offspring generation (mean AAO, 22.2 years) than that in the parental generation (mean AAO, 31.0 years) (P < 0.001). When only including the offspring generation who married, the AAO difference between the two generations was not significant (28.4 years vs 31.0 years, P = 0.151). Our findings suggest that a selection bias in the parental group might greatly impact the study of anticipation in schizophrenia. Other unavoidable biases associated with these analyses are discussed in the text. [source] Assessing the spawning season in common dentex (Dentex dentex) using microsatellitesAQUACULTURE RESEARCH, Issue 12 2008Yaisel J Borrell Abstract A set of five variable microsatellite markers was used for the genetic characterization of two common dentex (Dentex dentex) broodstocks from an experimental hatchery and for the screening of the egg batches spawned during the complete spawn season in 2006. After parentage assignment, simulations were performed for the hatchery 1 broodstocks; the microsatellite set correctly assigned over 93% of descendants to parents when one parent was known and 80% when neither parent was known. Of the 261 eggs that the DNA was correctly amplified from, 254 were successfully assigned to a parental couple. More than one female or male took part (at the same point in time) in the spawning season. However, we observed ,dominant' individuals that produced high proportions of the descendants (unequal reproductive success) in all the sampling periods, although the contributions of these dominant individuals could change over time. This phenomenon reduces the effective breeding numbers, and could lead to inbreeding if this factor is not taken into account when the next parental generation is obtained. This factor should also be considered in aquaculture selection programmes because the dominant breeders may not be the most interesting individuals for commercial or productive schemes. [source] | ||||||||||