INHERITANCE OF GROWTH RATE IN NEUROSPORA CRASSA: CROSSES BETWEEN PREVIOUSLY SELECTED LINES

1970 ◽  
Vol 12 (1) ◽  
pp. 1-9 ◽  
Author(s):  
K. E. Papa
Keyword(s):  
Growth Rate ◽  
Neurospora Crassa ◽  
Genetic Variance ◽  
Continuous Selection ◽  
Linear Growth Rate ◽  
Selected Lines ◽  
Gene Effects ◽  
Different Temperatures ◽  
Additive Gene ◽  
The Difference

Continuous selection for fast linear growth rate in Neurospora crassa at 18°, 25°, and 35 °C was effective. Crossing plateaued selection lines within the same temperature revealed that different combinations of genes were synthesized in each line. Most of these differences could be attributed to non-additive gene effects. Twelve cycles of selection within progeny from crosses between selected lines were effective, although the growth rate reached previously in the fastest parent was not surpassed.Crossing plateaued selection lines improved at different temperatures generated new genetic variance, thus indicating the fixation of different alleles in different lines with temperature. The difference between lines selected at different temperatures could be explained be the additive effect of two to three genes. Estimates of the average genetic variance were found to be highest among the progeny from crosses involving 35°-selection lines and lowest from crosses involving 18°-selection lines

The Science of Breeding and Its Application to the Breeder Genetic Algorithm (BGA)

1993 ◽  
Vol 1 (4) ◽  
pp. 335-360 ◽  
Author(s):  
Heinz Mühlenbein ◽  
Dirk Schlierkamp-Voosen
Keyword(s):  
Genetic Algorithm ◽  
Genetic Variance ◽  
Response To Selection ◽  
Gene Effects ◽  
Fitness Functions ◽  
Additive Gene ◽  
Regression Techniques ◽  
Algorithm Theory ◽  
And Control ◽  
Theoretical Results

The breeder genetic algorithm (BGA) models artificial selection as performed by human breeders. The science of breeding is based on advanced statistical methods. In this paper a connection between genetic algorithm theory and the science of breeding is made. We show how the response to selection equation and the concept of heritability can be applied to predict the behavior of the BGA. Selection, recombination, and mutation are analyzed within this framework. It is shown that recombination and mutation are complementary search operators. The theoretical results are obtained under the assumption of additive gene effects. For general fitness landscapes, regression techniques for estimating the heritability are used to analyze and control the BGA. The method of decomposing the genetic variance into an additive and a nonadditive part connects the case of additive fitness functions with the general case.

DIALLEL CROSSES OF REPLICATE SELECTED LINES OF RATS

1975 ◽  
Vol 55 (4) ◽  
pp. 479-486 ◽  
Author(s):  
J. J. RUTLEDGE ◽  
A. B. CHAPMAN
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Combining Ability ◽  
Body Weight Gain ◽  
Selected Lines ◽  
Gene Effects ◽  
Body Weights ◽  
Marginal Means ◽  
Additive Gene ◽  
Good Agreement

A 6 × 6 diallel experiment was conducted with two control lines (Ri), two lines (Ui) selected for increased and two lines (Di) selected for decreased 3- to 9-wk body weight gain. Traits studied were 2-, 3-, 6- and 9-wk body weights and 3- to 9-wk body weight gain. For all traits, marginal means for dams or sires ranked in the order U > R > D. There was good agreement between replicate dam lines and between replicate sire lines for general combining ability. There was no clear evidence of any specific combining ability (non-additive gene effects) from crosses of lines within or between selection treatments.

scholarly journals Genetic Variance Components in Cotton by Generation Mean Analysis

2021 ◽  
Vol 3 (2) ◽  
pp. 72-85
Author(s):  
A. Isong ◽  
A. Balu ◽  
A. Ahmed ◽  
J. O. Mbe ◽  
I. G. Mohammed ◽  
...  
Keyword(s):  
Variance Components ◽  
Quantitative Traits ◽  
Genetic Variance ◽  
Gene Action ◽  
Dominance Effect ◽  
Generation Mean Analysis ◽  
Seed Cotton ◽  
Gene Effects ◽  
Main Effect ◽  
Additive Gene

The mode of gene action for the expression of quantitative traits is decided by the predominance of variances due to additive, dominance and epistasis gene effects. In this experiment, involving four F1 crosses (TCH1716 x TCB37, TCH1705-101 x TCB209, KC2 x TCB26 and TSH0250 x DB3) of upland cotton, inheritance of major yield components by Generation Mean Analysis was investigated. The investigation revealed that both additive and dominance gene effects were involved in the expression of most of the yield contributing traits. One or more types of epistatic interaction effects were prevalent for all the characters and thus played a major role in the control of the characters. The inheritance of the traits was found to be complex in lieu of the low heritability estimates and genetic advance over mean. For seed cotton yield per plant, the dominance x dominance interaction effect was positively significant for all the crosses, the additive x dominance effect was positively significant only in cross 1 and the dominance main effect showed negative significant in all crosses. The dominance (h) and dominance x dominance (l) effects were of opposite signs in all the crosses indicating the presence of duplicate epistasis in all the crosses. To harness additive gene effects for improvement of some of the traits, breeding methods with postponement of selection to later generation should be adopted.

scholarly journals 447 PB 282 INHERITANCE OF FRUIT FIRMNESS IN GENETICALLY PARTHENOCARPIC PICKLING CUCUMBERS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 495c-495
Author(s):  
Kevin L. Cook ◽  
August C. Gabert ◽  
James R. Baggett
Keyword(s):  
Maternal Effects ◽  
Genetic Variance ◽  
Fruit Firmness ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Pickling Cucumber ◽  
The Us ◽  
Pickling Cucumbers ◽  
Additive Gene ◽  
High Heritability

The firmness of parthenocarpic (P) pickling cucumber cultivars is generally considered unacceptable for processing by the US pickling cucumber industry. Genetic improvement in firmness of P pickling cucumbers may increase their acceptability. Inheritance of fruit firmness (FF) in nonparthenocarpic (NP) cucumbers has been reported as quantitative but highly heritable with additive gene effects accounting for most of the genetic variation and no maternal effects. Genetic investigations were conducted at Brooks, Oregon, in 1992 and 1993 to determine the inheritance of FF in P cucumbers. High heritability for FF was found with most genetic variance attributed to additive gene effects when F1's from four P gynoecious inbreds as females and five NP monecious inbreds as males were used in 1992. Experiments in 1993, with inbred derived populations, revealed that dominant variance and maternal effects for FF may be substantial in certain populations with parthenocarpic germplasm.

scholarly journals On the Path to Thermo-Stable Collagen: Culturing the Versatile Sponge Chondrosia reniformis

Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 669
Author(s):  
Boaz Orel ◽  
Marco Giovine ◽  
Micha Ilan
Keyword(s):  
Growth Rate ◽  
Disease Transmission ◽  
Marine Invertebrates ◽  
Biotechnological Applications ◽  
Optimal Temperature ◽  
Alternative Source ◽  
Controlled System ◽  
Food Industries ◽  
Different Temperatures ◽  
The Difference

The collagen proteins family is sought-after in the pharmaceuticals, cosmetics, and food industries for various biotechnological applications. The most abundant sources of collagen are pigs and cows, but due to religious restrictions and possible disease transmission, they became less attractive. An alternative source can be found in marine invertebrates, specifically in sponges. Alas, two problems arise: (1). Growing sponges is complicated. (2). Sponge collagen has low heat tolerance, which can impose a problem for human biotechnological usage. To fill these gaps, we studied the collagen-abundant sponge Chondrosia reniformis. Two culture experiments were conducted: (1). A sea-based system examined the difference in growth rates of C. reniformis from different habitats, growing under natural seasonal conditions; (2). A land-based controlled system, which assessed the growth-rate of C. reniformis at different temperatures. The results reveal that C. reniformis from shallow habitats are growing larger and faster than individuals from colder, deeper habitats, and that the optimal temperature for C. reniformis growth is 25 °C. The results demonstrate that C. reniformis is highly fit for culture and can produce thermally stable collagen. Further research is needed to determine the best conditions for C. reniformis culture for collagen extract and other exciting materials for bioprospecting.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

scholarly journals SELECTION FOR BLOOD PRESSURE LEVELS IN MICE

Genetics ◽  
1974 ◽  
Vol 76 (3) ◽  
pp. 537-549
Author(s):  
Gunther Schlager
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Population Bottleneck ◽  
Control Line ◽  
Selected Lines ◽  
High Line ◽  
Selection For ◽  
Random Control

ABSTRACT Response to two-way selection for systolic blood pressure was immediate and continuous for about eight generations. In the twelfth generation, the High males differed from the Low males by 38 mmHG; the females differed by 39 mmHg. There was little overlap between the two lines and they were statistically significant from each other and from the Random control line. There appeared to be no more additive genetic variance in the eleventh and twelfth generations. Causes for the cessation of response are explored. This is probably due to a combination of natural selection acting to reduce litter sizes in the Low line, a higher incidence of sudden deaths in the High line, and loss of favorable alleles as both selection lines went through a population bottleneck in the ninth generation.—In the eleventh generation, the selected lines were used to produce F1, F2, and backcross generations. A genetic analysis yielded significant additive and dominance components in the inheritance of systolic blood pressure.

scholarly journals How informative is Wright's estimator of the number of genes affecting a quantitative character?

Genetics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 235-247 ◽  
Author(s):  
Z B Zeng ◽  
D Houle ◽  
C C Cockerham
Keyword(s):  
Genetic Variance ◽  
Estimation Procedure ◽  
Expected Value ◽  
Allele Frequencies ◽  
Quantitative Character ◽  
Base Population ◽  
Single Population ◽  
Number Of Genes ◽  
Selection Limit ◽  
The Difference

Abstract S. Wright suggested an estimator, m, of the number of loci, m, contributing to the difference in a quantitative character between two differentiated populations, which is calculated from the phenotypic means and variances in the two parental populations and their F1 and F2 hybrids. The same method can also be used to estimate m contributing to the genetic variance within a single population, by using divergent selection to create differentiated lines from the base population. In this paper we systematically examine the utility and problems of this technique under the influences of unequal allelic effects and initial allele frequencies, and linkage, which are known to lead m to underestimate m. In addition, we examine the effects of population size and selection intensity during the generations of selection. During selection, the estimator m rapidly approaches its expected value at the selection limit. With reasonable assumptions about unequal allelic effects and initial allele frequencies, the expected value of m without linkage is likely to be on the order of one-third of the number of genes. The estimates suffer most seriously from linkage. The practical maximum expectation of m is just about the number of chromosomes, considerably less than the "recombination index" which has been assumed to be the upper limit. The estimates are also associated with large sampling variances. An estimator of the variance of m derived by R. Lande substantially underestimates the actual variance. Modifications to the method can ameliorate some of the problems. These include using F3 or later generation variances or the genetic variance in the base population, and replicating the experiments and estimation procedure. However, even in the best of circumstances, information from m is very limited and can be misleading.

A Model of Wheat Grain Growth and Its Applications to Different Temperature and Carbon Dioxide Levels

1995 ◽  
Vol 22 (5) ◽  
pp. 843 ◽  
Author(s):  
YP Wang ◽  
RM Gifford
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Temperature Response ◽  
Rate Sensitivity ◽  
Temperature Sensitive ◽  
Potential Growth ◽  
Carbon Supply ◽  
The Difference ◽  
Carbon Dioxide Levels ◽  
Kernel Growth

Kernel growth after anthesis is simulated as a function of the potential kernel growth rate, current photosynthate production and mobilisation of stored reserves. The potential growth rate of the kernel is simulated as two temperature-sensitive processes, cell production and cell growth. The difference between the potential and actual growth rates of the kernel depends on the carbon supply to the free space of the kernel endosperm, while the carbon supply is itself affected by the actual kernel growth rate. Sensitivity analysis showed that the growth rate of the grain per plant is most sensitive to the potential growth rate of the kernel and number of kernels per plant. This model is able to simulate the observed rates of grain growth and leaf senescence from anthesis to physiological maturity for wheat plants grown in two CO2 concentrations. The simulated temperature response of grain growth agrees well with the experimenal observations.

Sign in / Sign up

Export Citation Format

Share Document