scholarly journals Drosophila melanogaster Selection for Survival after Infection with Bacillus cereus Spores: Evolutionary Genetic and Phenotypic Investigations of Respiration and Movement

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Junjie Ma ◽  
Andrew K. Benson ◽  
Stephen D. Kachman ◽  
Deidra J. Jacobsen ◽  
Lawrence G. Harshman
Keyword(s):  
Egg Production ◽  
Metabolic Cost ◽  
Dry Weight ◽  
Male Response ◽  
Pathogenic Agent ◽  
Respiration Rates ◽  
Evolutionary Genetic ◽  
Laboratory Populations ◽  
Selection For ◽  
Male Activity

Laboratory populations of D. melanogaster have been subjected to selection for survival after live spores of B. cereus were introduced as a pathogenic agent. The present study was designed to investigate correlated traits: respiration as a metabolic trait and movement as a behavioral trait. An underlying hypothesis was that the evolution of increased survival after B. cereus infection exerts a metabolic cost associated with elevated immunity and this would be detected by increased respiration rates. There was support for this hypothesis in the male response to selection, but not for selected-line females. Two phenotypic effects were also observed in the study. Females especially showed a marked increase in respiration after mating compared to the other assay stages regardless of whether respiration was measured per fly or adjusted by lean mass or dry weight. Given that mating stimulates egg production, it is feasible that elevated metabolism was needed to provision oocytes with yolk. Females also moved less than males, perhaps due to behaviors related to oviposition whereas elevated male activity might be due to behaviors associated with seeking females and courtship. Relatively low movement of females indicated that their elevated respiration after mating was not due to a change in locomotion.

Third generation progress in breeding white clover for resistance to root-knot nematode

1996 ◽  
Vol 6 ◽  
pp. 163-166
Author(s):  
J. Van den Bosch ◽  
C.F. Mercer
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Egg Production ◽  
Control Method ◽  
Dry Weight ◽  
Third Generation ◽  
Root Knot Nematode ◽  
Root Dry Weight ◽  
Wide Range ◽  
Meloidogyne Sp

Root-knot nematode (Meloidogyne sp.) reduces growth and nutrition of white clover (Trifolium repens L.) in New Zealand, and breeding resistant cultivars (with low galls per gram of root) is the preferred control method. Resistant and susceptible selections were bred from a wide range of white clover lines for three generations. In the third generation there were significant differences between seed lines from the selections for number of galls, root dry weight, visual growth score and galls/gram of root dry weight. Resistant selections had 43% of the susceptible selections' galls per gram, and 50% of the number of galls. Germplasm showing resistance to Meloidogyne spp. in the USA showed partial resistance to the local Meloidogyne sp. Two resistant and two susceptible genotypes were also compared for nematode egg production; resistant genotypes had a mean of 3,460 eggs/plant, compared to 25,030 for susceptible genotypes. Keywords: breeding, Meloidogyne sp., resistance, rootknot nematode, screening, selection, Trifolium repens, white clover

Selection for Egg Production

1960 ◽  
Vol 16 (1) ◽  
pp. 36-46
Author(s):  
Fred Skaller
Keyword(s):  
Egg Production ◽  
Selection For

Paracelsus’ 16 th Century Philosophy Applied to Current Evolutionary Genetics

2017 ◽  
Author(s):  
Jenna Kewin
Keyword(s):  
Sixteenth Century ◽  
Intimate Relationships ◽  
Genetic Disease ◽  
Genetic Research ◽  
Evolutionary Genetics ◽  
Immunodeficiency Virus ◽  
Evolutionary Genetic ◽  
Health And Disease ◽  
Potential Impact ◽  
Selection For

Paracelsus contributed greatly to medical philosophy in the early sixteenth century, yet his reputation was so tainted by his hypocrisy that he left few followers and is often forgotten. Many aspects of his teachings, however, can be applied to current theories governing evolutionary genetic research. His claim, “Where diseases arise, one can also find the roots of health” hints at the intimate relationships between health and  disease that are the foundations of fascinating research. In many devastating medical cases, it has been  found that expression of one genetic disease can confer resistance for another. Sickle­cell anemia sufferers have an increased resistance to malaria, cystic fibrosis is associated with decreased susceptibility to  influenza, tuberculosis and cholera, and even the human immunodeficiency virus (HIV­1) is theorized to  have stemmed from a selection for resistance to the Bubonic Plague. These examples demonstrate the ambiguities in distinguishing between health and disease. While scientists today would likely scoff at Paracelsus’ dated medical rants, when they discover a disease favoured by natural selection, one of the first questions is how it could have conferred a benefit ancestrally. Applying Paracelsus’ theories to a discipline as contrary to evolutionary genetics demonstrates both the robustness of his claims, and the potential impact philosophy can have on medical, scientific and sociological questions surrounding challenging  epidemics

scholarly journals Evolution of reduced pre-adult viability and larval growth rate in laboratory populations of Drosophila melanogaster selected for shorter development time

2000 ◽  
Vol 76 (3) ◽  
pp. 249-259 ◽  
Author(s):  
N. G. PRASAD ◽  
MALLIKARJUN SHAKARAD ◽  
VISHAL M. GOHIL ◽  
V. SHEEBA ◽  
M. RAJAMANI ◽  
...  
Keyword(s):  
Growth Rate ◽  
Drosophila Melanogaster ◽  
Development Time ◽  
Larval Growth ◽  
Dry Weight ◽  
Relative Reduction ◽  
Larval Growth Rate ◽  
Laboratory Populations ◽  
The Difference ◽  
Faster Development

Four large (n > 1000) populations of Drosophila melanogaster, derived from control populations maintained on a 3 week discrete generation cycle, were subjected to selection for fast development and early reproduction. Egg to eclosion survivorship and development time and dry weight at eclosion were monitored every 10 generations. Over 70 generations of selection, development time in the selected populations decreased by approximately 36 h relative to controls, a 20% decline. The difference in male and female development time was also reduced in the selected populations. Flies from the selected populations were increasingly lighter at eclosion than controls, with the reduction in dry weight at eclosion over 70 generations of selection being approximately 45% in males and 39% in females. Larval growth rate (dry weight at eclosion/development time) was also reduced in the selected lines over 70 generations, relative to controls, by approximately 32% in males and 24% in females. However, part of this relative reduction was due to an increase in growth rate of the controls populations, presumably an expression of adaptation to conditions in our laboratory. After 50 generations of selection had elapsed, a considerable and increasing pre- adult viability cost to faster development became apparent, with viability in the selected populations being about 22% less than that of controls at generation 70 of selection.

Genetic parameters for egg weight v. age curve, and other egg production and egg weight traits, in synthetic lines of chickens

1983 ◽  
Vol 34 (1) ◽  
pp. 85 ◽  
Author(s):  
BH Yoo ◽  
BL Sheldon ◽  
RN Podger
Keyword(s):  
Standard Deviation ◽  
Genetic Correlation ◽  
Egg Production ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Egg Mass ◽  
Control Line ◽  
Egg Weight ◽  
Egg Number ◽  
Selection For

An exponential curve, W = P-Qexp(- Rt), where W is egg weight at age t, was fitted to egg weights of individual pullets, and genetic parameters were estimated for P, Q and R, the residual standard deviation and other egg weight and egg production characters. The data consisted of records collected over six generations on more than 4000 pullets in two selection lines and a control line which originated from a synthetic gene pool of White Leghorn x Australorp crosses. The half-sib and offspring-on-parent regression estimates of heritability pooled over the lines were 0.23 and 0.33 for P, 0.14 and 0.20 for Q, and 0.14 and 0.25 for R. Genetic correlations were estimated to be -0.10 between P and Q, -0.46 between P and R, and 0.90 between Q and R. These estimates suggest that the egg weight v. age curve may be modified to increase the proportion of eggs in desirable weight grades and reduce the incidence of oversized eggs later in the production year. The genetic correlation between mean weight of first 10 eggs and egg weight at 62 weeks of age was estimated to be 0.68, further suggesting that early egg weight may be improved partly independently of late egg weight. The heritability estimates of egg mass output were not higher than those of egg number in spite of the highly heritable average egg weight being an important component of egg mass, probably because of the negative genetic correlation (r = -0.49) between egg number and average egg weight. The standard deviation of individual pullet's egg weights was moderately heritable and genetically correlated positively with egg weight characters and negatively with egg production; these estimates were consistent with the responses to selection for reduced egg weight variability observed elsewhere

scholarly journals Selection Criteria for Drought-Tolerant Bread Wheat Genotypes at Seedling Stage

2019 ◽  
Vol 11 (9) ◽  
pp. 2584 ◽  
Author(s):  
Hafiz Ahmed ◽  
Muhammad Sajjad ◽  
Mingju Li ◽  
Muhammad Azmat ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Selection Criteria ◽  
Dry Weight ◽  
Shoot Length ◽  
Seedling Stage ◽  
Chlorophyll B ◽  
Fresh Weight ◽  
Drought Tolerant ◽  
Selection For ◽  
Thermo Stability

Diminishing water resources as a result of excessive use of water for irrigation and climate change posture a severe global threat to food security. Herein, an experiment was conducted to determine the selection criteria for drought-tolerant bread wheat genotypes at the seedling stage using morphological and photosynthetic pigmentation-related traits. A panel of 105 wheat landraces, historical Pakistani varieties, and advance breeding lines were evaluated under normal and drought stress using factorial completely randomized design. The root length, fresh weight, dry weight, cell membrane thermo-stability, and chlorophyll b were positively correlated among themselves under both normal and stress conditions. Hence, selection of any one of these traits enhances the performance of other traits. The shoot length was non-significant and negatively associated with all other studied characters except relative water content. The results suggested that selection for shoot length could not improve genetic gain for drought tolerance. Out of 10 principal components (PCs), the first three PCs were showed significant genetic variation under both conditions. The first three PCs showed 74.6% and 76% cumulative genetic variation under normal and drought conditions, respectively. Based on PCA, 10 drought-tolerant and five drought-susceptible genotypes were identified. Overall results suggested that selection for root length, fresh weight, dry weight, cell membrane thermo-stability, and chlorophyll b at the seedling stage would improve genetic gain for drought tolerance. The outperforming genotypes under drought stress conditions can be useful in future wheat breeding programs, and early selection for the traits recommended in this study will be effective for developing high-yielding and drought-tolerant wheat varieties.

scholarly journals Some results of breeding a predatory stink bug of Perillus bioculatus F. (Hemiptera, Pentatomidae) in the Republic of Moldova

2020 ◽  
Vol 21 ◽  
pp. 00024
Author(s):  
Dina Elisovetcaia ◽  
Valeriu Derjanschi ◽  
Irina Agas’eva ◽  
Mariya Nefedova
Keyword(s):  
Egg Production ◽  
Galleria Mellonella ◽  
Food Preferences ◽  
Leaf Beetle ◽  
Stink Bug ◽  
Leaf Beetles ◽  
Republic Of Moldova ◽  
Perillus Bioculatus ◽  
Laboratory Populations ◽  
The Impact

The impact of insect artificial diet on the egg production of females was examined for L29 consequently generations of laboratory populations Perillus bioculatus (F.) (Hemiptera: Pentatomidae, Asopinae). Particular attention is paid to the overwintered generation, which plays a key role in the rehabilitation of the predator populations after hibernation. It was shown that with an increase in the number of laboratory generations of a predator (from L13 to L29), egg production of P. bioculatus females significantly decreases – from 16.4-35.7 to 15.0-27.5 eggs / female in terms of the total number of females in the laboratory populations. The proportion of eggs laid by females of winter generation was the lowest when feeding on Galleria mellonella larvae. Was established food preferences among the assortment of native for Republic of Moldova leaf beetles: Entomoscelis adonidis Pallas 1771, Chrysolina herbacea (Duftschmid, 1825) and C. coerulans (Scriba, 1791). P. bioculatus imago overwintered generation refused to feed on E. suturalis larvae and imago, probably because of the isoquinoline alkalods contained in the hemolymph of the leaf beetle. Studies have shown that supplementary feeding with imago of E. adonidis, C. herbacea and C. coerulans increases from 8.3±0.5/50 till 11.2±0.7/104 per day / total egg production of P. bioculatus females of the overwintered generation.

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