Direct and indirect effects of male genital elaboration in female seed beetles

Our understanding of coevolution between male genitalia and female traits remains incomplete. This is perhaps especially true for genital traits that cause internal injuries in females, such as the spiny genitalia of seed beetles where males with relatively long spines enjoy a high relative fertilization success. We report on a new set of experiments, based on extant selection lines, aimed at assessing the effects of long male spines on females in Callosobruchus maculatus . We first draw on an earlier study using microscale laser surgery, and demonstrate that genital spines have a direct negative (sexually antagonistic) effect on female fecundity. We then ask whether artificial selection for long versus short spines resulted in direct or indirect effects on female lifetime offspring production. Reference females mating with males from long-spine lines had higher offspring production, presumably due to an elevated allocation in males to those ejaculate components that are beneficial to females. Remarkably, selection for long male genital spines also resulted in an evolutionary increase in female offspring production as a correlated response. Our findings thus suggest that female traits that affect their response to male spines are both under direct selection to minimize harm but are also under indirect selection (a good genes effect), consistent with the evolution of mating and fertilization biases being affected by several simultaneous processes.

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Estimation of Genetic Parameters and Selection Response for Reproductive and Growth Traits in Rideau-Arcott sheep

Canadian Journal of Animal Science ◽

10.1139/cjas-2019-0152 ◽

2020 ◽

Author(s):

Mohammed Naser Boareki ◽

Luiz Brito ◽

Angela Cánovas ◽

V.R. Osborne ◽

Flavio S Schenkel

Keyword(s):

Litter Size ◽

Genetic Parameters ◽

Growth Traits ◽

Reproductive Traits ◽

Selection Response ◽

Direct Selection ◽

Correlated Response ◽

Response To Selection ◽

Weaning Weight ◽

Selection For

The goal of this study was to estimate genetic parameters and predict direct and correlated response to selection for lamb growth traits and ewe reproductive traits, based on single trait selection or combining multiple traits in an optimum index that targets total litter post-weaning weight in the first lambing as the main selection goal. Heritability estimates ranged from 0.04 to 0.19. Genetic correlations between growth and reproductive traits ranged from -0.24 to 0.15. The indirect response to selection for reproductive traits in later lambings, by selecting on first lambing performance, was 11 to 25% greater than direct selection. The response to indirect selection for composite reproductive traits, i.e. total weaning weight or total post-weaning weight, by selecting on individual lamb weaning weight or post-weaning weight was 1 to 69% greater than direct selection, but it was accompanied by a negative response on litter size. However, combining alternate growth and reproductive traits in optimum selection index resulted in correlated response of up to 96% greater than direct selection response for reproductive traits without a negative response on litter size. Therefore, multiple trait selection using an index of component traits was more effective than direct selection for a composite trait.

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Relationship between milk composition and yield of milk, fat and protein in Red Danish cattle

Animal Science ◽

10.1017/s0003356100026465 ◽

1968 ◽

Vol 10 (4) ◽

pp. 445-450 ◽

Cited By ~ 6

Author(s):

K. Christensen

Keyword(s):

Milk Yield ◽

Milk Fat ◽

Genetic Correlations ◽

Protein Yield ◽

Direct Selection ◽

Correlated Response ◽

Logarithmic Scale ◽

Progeny Testing ◽

Fat Yield ◽

Selection For

The relationships among five traits in dairy cattle (milk yield, fat yield, protein, fat % and protein %) were examined on the original and on a logarithmic scale. The data comprised the records on 5333 Red Danish cows tested at the Danish Progeny Testing Stations during the years 1960–66. None of the heritabilities or the correlations among the variates were altered appreciably by transformation. For the five traits heritability estimates were 0·56, 0·80, 0·65, 0·64 and 0·56, respectively. Phenotypic and genetic correlations among milk yield, fat yield and protein yield were all very high, about 0·95. The correlations between fat % and protein % were about 0·6. The coefficient of variation of a variate proved to be a good approximation of the standard deviation of the transformed variate even for milk, fat and protein yield with coefficients of variation of 17–18%. It was concluded that little is likely to be gained by using index selection for fat yield and protein yield. However, about 90% of the response obtainable by direct selection for fat or protein yield could be obtained merely by selection for milk yield. A large correlated response for protein yield could be obtained by selecting for fat yield.

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MASS SELECTION FOR POSTWEANING GROWTH IN SWINE. III. CORRELATED RESPONSE IN WEANING WEIGHT AND FEED EFFICIENCY TO RECURRENT SELECTION FOR POSTWEANING AVERAGE DAILY GAIN IN SWINE

Canadian Journal of Animal Science ◽

10.4141/cjas73-027 ◽

1973 ◽

Vol 53 (2) ◽

pp. 173-178

Author(s):

G. W. RAHNEFELD

Keyword(s):

Genetic Correlation ◽

Feed Efficiency ◽

Average Daily Gain ◽

Direct Selection ◽

Correlated Response ◽

Mass Selection ◽

Total Response ◽

Weaning Weight ◽

Selection For ◽

Daily Gain

Correlated response in weaning weight and feed efficiency were estimated for a genetically variable population of swine selected during nine generations for postweaning average daily gain. Total response in weaning weight to direct selection for gain was 0.03 kg per generation. This was 3.1% of the predicted response. The estimate of genetic correlation between postweaning average daily gain and weaning weight was found high and positive (> 1). Total response in feed efficiency to direct selection for gain was −0.58 kg per generation. This was 10% of the predicted response. The estimate of genetic correlation between postweaning gain and feed efficiency was −0.35.

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STUDIES ON THE SCUTELLAR BRISTLES OF DROSOPHILA MELANOGASTER. II. LONG-TERM SELECTION FOR HIGH BRISTLE NUMBER IN THE OREGON RC STRAIN AND CORRELATED RESPONSES IN ABDOMINAL CHAETAE

Genetics ◽

10.1093/genetics/71.4.567 ◽

1972 ◽

Vol 71 (4) ◽

pp. 567-595

Author(s):

B L Sheldon ◽

M K Milton

Keyword(s):

Population Level ◽

Direct Selection ◽

Correlated Response ◽

Selection Line ◽

Wild Type ◽

Correlated Responses ◽

Bristle Number ◽

Dominance Level ◽

The Mean ◽

Selection For

ABSTRACT Results are presented of 135 generations of selection for high scutellar bristle number in two lines M and M3 derived from the same original mating of one female with 5 bristles by one male with 4 bristles, the latter being the wild-type canalised phenotype. Results are also given of two relaxed lines per line and of a reselection line M2 derived from the first relaxed line of line M which had regressed almost to base population level. The effect of introducing the sc1 allele into the M and M3 selected backgrounds was studied at generations 39–44. At the end of selection the effect of an extra dose of sc+ was also studied in males of all selected backgrounds. The correlated responses in abdominal bristles were followed in all lines.—Considering their common origin, the selection lines differed markedly in pattern of scutellar response and in most other aspects observed, namely correlated responses in abdominals and p.c. scutellars, sex differences, and behaviour on relaxation. Selection limits for scutellar bristles in lines M and M2 were equal to or greater than the most extreme reported in the literature.—The probit span of the canalised 4 bristle class decreased in each selection line as the mean scutellar bristle number increased, and increased again in the relaxed lines as the mean bristle number decreased. In the context of an hypothesis that canalisation at 4 bristle is due to regulation of the scute locus, this result is now interpreted as being due mainly to selection for poor regulators of sc+, in contrast to a previous interpretation that only the minor gene background was altered by selection, the canalisation (regulation) genotype not being affected.—Introducing the sc 1 allele into the selected backgrounds M and M3 showed a reduced effect on sc 1 flies compared with sc+ flies, and an interaction of sc 1 and sc+ with selected background. sc 1 flies had about the same number of bristles in both backgrounds though the mean of sc+ flies in line M was about 3? higher than in line M3. Dominance of sc+ to sc 1 was reduced slightly in M3. However, the effect of an extra dose of sc+ at the end of selection was about the same as in unselected in all lines, so the first or dominance level of regulation of the scute locus was not significantly affected by selection, though the second or canalisation level of regulation was.—A large positive correlated response in abdominal bristles occurred in all lines. The response in line M was about twice that in M2 and M3 and was in fact as large as can be obtained from direct selection on abdominals. In line M some genes may have been selected with a proportionately greater effect on abdominals than on scutellars. This is supported by the further observation in line M that the abdominal scores of flies with particular scutellar bristles scores increased as the scutellar mean increased. An attempt was made to apply to these results Rendel's (1962) model of competition between scutellars and abdominals for common bristle-making resources. This could not be done satisfactorily mainly because the assumptions in the model about the similarity of effects in scute and wild-type flies were not met in the present material.

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BREEDING FOR FEED EFFICIENCY: SWINE AND DAIRY CATTLE

Canadian Journal of Animal Science ◽

10.4141/cjas84-061 ◽

1984 ◽

Vol 64 (3) ◽

pp. 505-512 ◽

Cited By ~ 11

Author(s):

B. W. KENNEDY

Keyword(s):

Growth Rate ◽

Dairy Cattle ◽

Feed Efficiency ◽

Large Scale ◽

Experimental Studies ◽

Direct Selection ◽

Correlated Response ◽

Selection For ◽

Potential Improvement ◽

Current Selection

Feed efficiency in dairy cattle is moderately heritable and selection for its improvement theoretically would be effective. Despite this, direct selection for feed efficiency is not practiced in dairy cattle. Growth of milk recording programs which monitor feeding information has made selection for feed efficiency, or at least efficiency of concentrate conversion, possible on a large scale. However, it has been estimated that correlated response to direct selection for increased milk yield probably results in 70–95% of the potential improvement in feed efficiency that could be achieved through direct selection for feed efficiency. Current selection practices for increased body size may be detrimental to feed efficiency. In swine also, little direct selection for improved feed efficiency is practiced. Experimental studies for selection for feed efficiency have been less successful than expected. Correlated response from selection for an index that combines growth rate and backfat seems to be as effective in improving feed efficiency as direct selection. Development of automated feeding devices which allow measurement of individual feed intake under group penning will facilitate monitoring of and selection for improved feed efficiency. Key words: Selection, feed efficiency, swine, dairy cattle

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Correlated response in longevity from direct selection for production in the South African Jersey breed

South African Journal of Animal Science ◽

10.4314/sajas.v42i1.5 ◽

2012 ◽

Vol 42 (1) ◽

Author(s):

J Du Toit ◽

JB Van Wyk ◽

A Maiwashe

Keyword(s):

South African ◽

Direct Selection ◽

Correlated Response ◽

The South ◽

Selection For

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Trends in genetic and environmental parameters, genetic correlations, and response to indirect selection for 10-year volume in a Norway spruce clonal experiment

Canadian Journal of Forest Research ◽

10.1139/x89-136 ◽

1989 ◽

Vol 19 (7) ◽

pp. 897-903 ◽

Cited By ~ 8

Author(s):

B. G. Bentzer ◽

G. S. Foster ◽

A. R. Hellberg ◽

A. C. Podzorski

Keyword(s):

Norway Spruce ◽

Genetic Correlations ◽

Environmental Parameters ◽

Volume Index ◽

Direct Selection ◽

Correlated Response ◽

Diameter At Breast Height ◽

Breast Height ◽

Selection For ◽

Efficient Selection

Seventy-five clones of Norway spruce (Piceaabies (L.) Karst.) were tested for height, diameter, and volume at two locations in southern Sweden. Total height was measured at seven ages from age 1 to 10 years, whereas diameter at breast height was measured and volume index calculated only at age 10. Clone effects were consistently significant for all traits, whereas clone × location interaction effects only showed significance for diameter at breast height at age 10, volume index, and height at age 3. Location effects for height were small and error effects large, up to age 6. Between ages 7 and 10, location effects increased considerably, while error effects decreased correspondingly. Clone-mean heritability for height remained stable from years 3 to 10, but was slightly higher at age 1. Genetic correlations between traits were generally large, which made efficient selection for height possible as early as age 4. The correlated response in volume index at age 10, when selecting for height at age 4 or later, was exceptionally good, and it provided gain estimates in volume that were as large as or larger than estimates from direct selection for volume index at age 10.

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Seed yield can be explained by altered yield components in field-grown western wheatgrass (Pascopyrum smithii Rydb.)

Scientific Reports ◽

10.1038/s41598-019-54586-0 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Zhao Chen ◽

Junpeng Niu ◽

Xinlong Cao ◽

Wenbo Jiang ◽

Jian Cui ◽

...

Keyword(s):

Seed Yield ◽

Yield Components ◽

Seed Weight ◽

Antagonistic Effect ◽

Yield Component ◽

Direct Selection ◽

Pascopyrum Smithii ◽

Western Wheatgrass ◽

Selection For ◽

High Seed Yield

AbstractWestern wheatgrass (Pascopyrum smithii Rydb.) is an important cool-season forage and turfgrass. However, due to seed dormancy and poor seedling vigor, it is difficult to develop high seed yield production systems, and assessing these components in response to seed yield. Based on multifactor orthogonally designed field experimental plots under various field management regimes, the effects of numbers of fertile tillers m−2 (Y1), spikelets/fertile tiller (Y2), florets/spikelet (Y3), seed numbers/spikelet (Y4), and seed weight (Y5) on seed yield (Z) were determined over three successive years. Correlation analysis indicated that fertile tillers (Y1) was the most important seed yield component. And the biggest contribution of those five yield component is fertile tillers (Y1), followed by seed numbers/spikelet (Y4), spikelets/fertile tiller (Y2), florets/spikelet (Y3) and seed weight (Y5), respectively. By using ridge regression analysis, we have developed an accurate model of seed yield with its five components. Finally, the results of synergism and antagonism among these yield components on seed yield showed that fertile tillers and seed numbers/spikelet had an antagonistic effect on seed yield. Therefore, selection for high seed yield by direct selection for large values of fertile tillers and seed numbers/spikelet would be the most effective breeding strategy for western wheatgrass.

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