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Genetic covariance between two traits generates correlated responses to selection, and may either enhance or constrain adaptation. Silene latifolia exhibits potentially constraining genetic covariance between specific leaf area (SLA) and flower number in males. Flower number is likely to increase via fecundity selection but the correlated increase in SLA increases mortality, and SLA is under selection to decrease in dry habitats. We selected on trait combinations in two selection lines for four generations to test whether genetic covariance could be reduced without significantly altering trait means. In one selection line, the genetic covariance changed sign and eigenstructure changed significantly, while in the other selection line eigenstructure remained similar to the control line. Changes in genetic variance–covariance structure are therefore possible without the introduction of new alleles, and the responses we observed suggest that founder effects and changes in frequency of alleles of major effect may be acting to produce the changes.

The role of sexual selection in the context of harvest-induced evolution is poorly understood. However, elevated and trait-selective harvesting of wild populations may change sexually selected traits, which in turn can affect mate choice and reproduction. We experimentally evaluated the potential for fisheries-induced evolution of mating behaviour and reproductive allocation in fish. We used an experimental system of zebrafish (Danio rerio) lines exposed to large, small or random (i.e. control) size-selective mortality. The large-harvested line represented a treatment simulating the typical case in fisheries where the largest individuals are preferentially harvested. We used a full factorial design of spawning trials with size-matched individuals to control for the systematic impact of body size during reproduction, thereby singling out possible changes in mating behaviour and reproductive allocation. Both small size-selective mortality and large size-selective mortality left a legacy on male mating behaviour by elevating intersexual aggression. However, there was no evidence for line-assortative reproductive allocation. Females of all lines preferentially allocated eggs to the generally less aggressive males of the random-harvested control line. Females of the large-harvested line showed enhanced reproductive performance, and males of the large-harvested line had the highest egg fertilization rate among all males. These findings can be explained as an evolutionary adaptation by which individuals of the large-harvested line display an enhanced reproductive performance early in life to offset the increased probability of adult mortality due to harvest. Our results suggest that the large-harvested line evolved behaviourally mediated reproductive adaptations that could increase the rate of recovery when populations adapted to high fishing pressure come into secondary contact with other populations.

Food products that are high in fiber and low in glycemic impact are healthier. Amylose is a form of resistant starch that mimics dietary fiber when consumed. A durum wheat (Triticum durum) line was created that lacks starch synthase IIa (SSIIa) activity, a key enzyme in amylopectin biosynthesis, by identifying a null mutation in ssIIa-B following mutagenesis of a line that has a naturally occurring ssIIa-A null mutation. Our objective here was to compare seed, milling, pasta, and nutritional characteristics of the SSIIa null line with a wild-type control line. The SSIIa null line had increased amylose and grain protein with lower individual seed weight and semolina yield. Refined pasta prepared from the SSIIa null semolina absorbed less water, had increased cooking loss, had a shorter cook time, and was considerably firmer even after overcooking compared with the wild-type line. Color of the SSIIa null cooked and uncooked pasta was diminished in brightness compared with the wild type. Nutritionally, the S...

Frost (Fst) is a candidate gene associated with the response to cold in Drosophila melanogaster because Fst mRNA accumulation increases during recovery from low temperature exposure. We investigated the contribution of Fst expression to chill-coma recovery time, acute cold tolerance and rapid cold hardening (RCH) in adult D. melanogaster by knocking down Fst mRNA expression using GAL4/UAS-mediated RNA interference. In this experiment, four UAS-Fst and one tubulin-GAL4 lines were used. We predicted that if Fst is essential for cold tolerance phenotypes, flies with low Fst mRNA levels should be less cold tolerant than flies with normal levels of cold-induced Fst mRNA. Cold-induced Fst abundance and recovery time from chill-coma were not negatively correlated in male or female flies. Survival of 2 h exposures to sub-zero temperatures in Fst knockdown lines was not lower than that in a control line. Moreover, a low temperature pretreatment increased survival of severe cold exposure in flies regardless of Fst abundance level during recovery from cold stress, suggesting that Fst expression is not essential for RCH. Thus, cold-induced Fst accumulation is not essential for cold tolerance measured as chill-coma recovery time, survival to acute cold stress and RCH response in adult D. melanogaster.

Summary We analysed an outbreed mouse line which was selected for the phenotype ‘high fertility’ for 158 generations. During this selection period the mouse strain increased the number of offspring per litter from 10.4 to 17.1 and the total litter weight up to ~160%. In this study, we initially characterize the reproductive phenotype of high fertility males. Surprisingly, male bucks of the fertility line (FL1) show reduced percentage of motile and progressive motile spermatozoa; however, other sperm motility characteristics (e.g. velocity parameters) are improved compared with an unselected control line. Cytometrical investigation of the testicular cell-type composition indicated a significant increased concentration of diploid cells by a concomitant reduction in haploid cells in the testicular parenchyma of FL1. Furthermore, total testosterone concentrations in blood are dramatically increased in FL1 (>20 ng/mL). In line with increased testosterone levels, we observed increased expression rates of steroidogenic key enzymes Cyp11 and Cyp17 from FL1 testis samples. These data indicate that FL1 males have a manifest ‘high fertility phenotype’. Diallelic crosses imply that male-only contribution largely determines the reproductive outcome in cross-breeding experiments. FL1 therefore is a promising model for future investigations on male factor (in)fertility. Our observation might also offer valuable cues for human reproductive medicine.

To determine whether genetic improvement could be attained through a selective breeding programme, divergent selection for shell length was conducted in a base population of the Manila clam, Ruditapes philippinarum. The 10% largest and 10% smallest clams were selected as parents for the upward-selected and downward-selected lines, respectively. Equal numbers of clams were randomly chosen to serve as parents for the control line before the selection. The selected and control lines were reared under the same environmental conditions at larvae, juvenile, and grow-out stages. The values of standardized responses to selection (SR) and realized heritability ( at the age of 360 d were 0.268 and 0.165 for the upward-selected line and 0.341 and 0.260 for the downward-selected line, respectively. Asymmetric differences were evident between the upward-selected and downward-selected lines in both SR and . Performance in shell length is improved by 3.55% in the upward-selected line after one generation, indicating that mass selection for shell length in a base population of the Manila clam, R. philippinarum, is effective and encouraging.

We show that two complementary asymmetric isolating mechanisms, likely mediated by divergence in body size, underlie the evolution of incipient reproductive isolation between a set of Drosophila melanogaster populations selected for rapid development and their ancestral controls. Selection has led to great reduction in body size in the fast developing lines. Small males belonging to fast developing lines obtain few matings with large control females, both in presence and absence of large control line males, giving rise to unidirectional, premating isolation caused by sexual selection. Conversely, small selected line females suffer greatly increased mortality following mating with large control males, causing unidirectional postcopulatory prezygotic isolation. We discuss preliminary evidence for evolution of reduced male harm caused to females upon mating in the fast developing lines, and speculate that the females from these lines have coevolved reduced resistance to male harm such that they can no longer resist the harm caused by males from control lines. This potentially implicates differing levels of sexual conflict in creating reproductive barrier between the selected line females and the control males. We also show that a large difference in development time is not sufficient to cause postzygotic incompatibilities in the two sets of populations reaffirming the belief that prezygotic isolation can evolve much earlier than postzygotic isolation.

Summary Ovulation rate (OR) is an important component of litter size, but mutation(s) in gene(s) underlying OR QTL have yet to be identified in pigs. Markers within an OR QTL on SSC3 were genotyped in three white composite lines selected for ten generations for increased OR or uterine capacity (UC), with one line being an unselected control. Numbers of corpora lutea (CL) and UC (number of fully formed fetuses) were collected at approximately 105 days of gestation, as well as ovary weight (OW), uterine length (UL) and uterine weight (UW) measurements at 160 d of age in generation 12 and 13 females from all three lines. Six microsatellites and ten single nucleotide polymorphisms (SNPs; 0–42 cM) were genotyped in pigs from all lines of generations 11 through 13. The allele frequencies of 24269.1, SW2429, 7907.2 and 7637.2 were different (P

A selective breeding program was initiated with a wild population of anadromous brook trout Salvelinus fontinalis from the Laval River, Quebec. The objective was to develop a new strain characterized by improved growth and reduced precocious sexual maturation. A control line was maintained by use of random within-family selection. Length and weight were measured and sexual maturity (mature or not mature) was determined at the end of the second year of growth (22 months of age). In the selected line, phenotypic variance, additive genetic variance, and heritability for weight within the selected families were reduced. A comparison between generations showed that fish weight at 22 months in the selected line increased by 23.1% from the F1 to the F2 generation and by 32.1% from the F2 to the F3 generation. The control line increased similarly in weight from the F1 to the F2 generation (34.7%) but not thereafter; this result was probably due to the domestication effect in the first generation after ca...

• Reduced lignin content in perennial crops has been sought as a means to improve biomass processability for paper and biofuels production, but it is unclear how this could affect wood properties and tree form. • Here, we studied a nontransgenic control and 14 transgenic events containing an antisense 4-coumarate:coenzyme A ligase (4CL) to discern the consequences of lignin reduction in poplar (Populus sp.). During the second year of growth, trees were grown either free-standing in a field trial or affixed to stakes in a glasshouse. • Reductions in lignin of up to 40% gave comparable losses in wood strength and stiffness. This occurred despite the fact that low-lignin trees had a similar wood density and up to three-fold more tension wood. In free-standing and staked trees, the control line had twice the height for a given diameter as did low-lignin trees. Staked trees had twice the height for a given diameter as free-standing trees in the field, but did not differ in wood stiffness. • Variation in tree morphogenesis appears to be governed by lignin x environment interactions mediated by stresses exerted on developing cells. Therefore our results underline the importance of field studies for assessing the performance of transgenic trees with modified wood properties.

Summary Two C-repeat binding factor genes (EguCBF1a ⁄ b), isolated from E. gunnii and differentially cold-regulated, were constitutively overexpressed in a cold-sensitive Eucalyptus hybrid. In addition to the expected improvement on freezing tolerance, some resulting transgenic lines (EguCBF1a-OE and EguCBF1b-OE) exhibited a decrease in stomata density and an over-accumulation of anthocyanins also observed to a lesser extent in a cold-acclimated control plant. Given that the induction of five putative CBF target genes was observed in CBF-overexpressing lines as well as in the coldacclimated control line, these phenotypes might be related to cold acclimation. In comparison with the control plant, the most altered transgenic line (EguCBF1a-OE A1 line), exhibited reduced growth and better water retention capacity. This modified phenotype includes reduced leaf area and thickness associated with a decrease in cell size, as well as a higher oil gland density and a wax deposition on the cuticle. Surprisingly, the EguCBF1b-OE B9 line, with a level of transgene expression equivalent to the A1 line, showed a less marked phenotype, suggesting a difference in transactivation efficiency between EguCBF1A and B factors. The features of these transgenic lines provide the first signs of adaptive mechanisms controlled by CBF transcription factors in an evergreen broad-leaved tree. These data also open new prospects towards genetic improvement on Eucalyptus for freezing tolerance.

The beet armyworm, Spodoptera exigua, is an important migratory insect pest in tropical and subtropical regions worldwide. The current study investigated genetic variation in the flight capacity of both female and male moths, using a quantitative genetics approach. The offspring-parent regression showed that parents had a significant influence on the flight duration of offspring, and the heritability estimated as 0.302. The upward selection increased mean flight duration from 123.7 to 284.6 min in females and from 113.9 to 254.0 min in males during 8 h of flight test; by contrast, downward selection decreased it from 123.7 to 65.6 min in females and from 113.9 to 29.8 min in males, while it did not change significantly in either females or males of the control line over eight generations. The mean realized heritability was estimated as 0.432 based on upward selection but 0.130 on downward selection, suggesting the asymmetry of response to selection on flight capacity. Reciprocal crosses between the two selected lines confirmed the dominance of 'long-flying genes' in the inheritance of flight capacity. A positive genetic correlation was found between increased flight duration and pupal weight. The presence of such additive genetic variance and covariance for flight capacity and the fitness trait, pupal weight, in the population of S. exigua may have underpinned the evolution of its migratory behaviour.

Summary The polymorphism of five enzyme loci (amylase, alkaline phosphatase, albumin, for 4-week body weight was compared to that of the unselected control line (C). for 4 week body weight was compared to that of the unselected control line (C). Three loci in the C line and two in the P line demonstrated polymorphism. Plasma amylase was separated into six bands and zymograms were classified on the basis of these bands into nine phenotypes. Three of the nine types were of relatively high activity and six were of relatively low activity. All nine types were found in the C line, whereas, all birds of the P line had only the most active type. Two alkaline phosphatase alleles (Akp-2B and Akp-2C) were segregating in the C line. Gene frequencies of alkaline phosphatase for the Akp-2B allele were 0.92 in the C line and 1.00 in the P line. Two albumin alleles (AlbQ1 and AlbQ2) were segregating in both populations. Gene frequencies for the AlbQ1 allele were 0.74 in the C line and 0.81 in the P line. Two red cell esterase-D alleles (Es-DF and Es-Ds) were segregating in both populations. The gene frequency for the Es-Ds allele (0.61) was higher than that of the Es-DF allele in the C line. In the P line the frequency of the Es-DF allele was higher than that of the Es-Ds allele. Heterozygosities of the C and P lines were estimated as 0.2258 and 0.1560 respectively. The relative inbreeding coefficient of the P line, calculated from heterozygosities was 0.31.

Stylet penetration behaviors of cotton aphids Aphis gossypii Glover on a transgenic cotton line “GK-12” expressing Bt toxic protein of Cry1A (Bt cotton) and a non-Bt conventional cotton line “Simian-3” (CK cotton) were recorded with the direct current electrical penetration graph (DC-EPG) technique. Cotton aphids reared on Bt cotton (abbreviated as Bt-aphids) and its parental non-Bt control line (CK-aphids) for more than 20 generations each, were used for recordings on two cotton lines. Among 47 selected parameters reflecting the activities of aphid stylets within plant tissues, there were eight parameters of CK-aphids showing significant differences between the performances of CK-aphids on Bt cotton and CK cotton, while for Bt-aphids, all the parameters were statistically equal between the performances on the two cotton lines. All parameters with significant differences indicated that CK-aphids could penetrate into Bt cotton more easily, but the phloem saps of Bt cotton were not as good as those of regular cotton for CK-aphids. Based on the present results, we concluded that there were some factors in Bt cotton affecting penetration behaviors of CK-aphids, but it just took several generations for CK-aphids to completely adapt Bt cotton, and Bt-aphids could feed on two cotton lines without difficulty.

This study investigated whether genetic selection on a divergent behavioural trait of fearfulness (tonic immobility duration) was related to changes in the nervous control of the heart. Quail selected for either long or short tonic immobility (LTI or STI, respectively) duration was compared with an unselected control line (CTI). The autonomic control of the heart was assessed by heart rate variability analysis and pharmacological blockades. Quail were surgically fitted with a telemetric device. Heart rate before injection did not differ between the three lines. The vagal-sympathetic effect (VSE) at rest differed significantly from 1 in CTI and STI quail, suggesting that parasympathetic activity was dominant. In LTI quail, VSE did not differ from 1, suggesting a balance between parasympathetic and sympathetic activities. The intrinsic heart rate reached after the successive injections of propranolol and atropine did not differ between lines and was higher than the heart rate at rest in STI, which was in line with results of VSE at rest. After atropine injection, the sympathetic activity indicated by the low-frequency power was lower in CTI than in the two selected quail. After propranolol injection, the parasympathetic activity indicated by the root of the mean squares of successive differences and the high-frequency power was higher in STI than in CTI and LTI quail. Selection on tonic immobility duration thus appears to be associated with changes in the sympathovagal control of the heart, which may influence behavioural responses to stressful situations.

The objective of this study was to determine if selection response for increased litter size in pigs could be partially attributed to three type 1 marker loci coding for genes known to affect litter size: oestrogen receptor (ESR), retinol-binding protein 4 (RBP4) and follistatin (FS). In the high litter size line (LS), pigs from the largest litters, based on number of pigs born alive (NBA), were retained to parent the next generation. A randomly selected control line (LC) was maintained. Gilts were reared in litters of 10 pigs or less to minimize maternal effects. Pigs were measured at generations 10-12. Additional traits scored were number of fully formed pigs (NFF) and number of mummified fetuses (MUM). Breeding values for NFF and NBA were greater (p < 0.05) in LS than LC in generations 11 and 12, but no significant line differences were found for MUM. The A allele of the ESR locus was fixed in both lines. After adjustment for effects of genetic drift, frequency of the two alleles segregating for the FS and RBP4 loci did not differ significantly between lines. No significant additive or dominance effects of the FS markers were detected for NFF, NBA and MUM in either LS or LC. Response to selection for increased litter size could not be attributed to effects at the ESR, RBP4 or FS loci.

Summary Data on mice selected for litter size over 122 generations have been analysed in order to reveal the effect of long-term selection on responses and changes in variances over a long selection period. Originally, three lines were established from the same base population, namely an H line selected for large litter size, an L line selected for small litter size and a K line without selection. In generation 122, the mean number of pups born alive (NBA) was 22 for the H line and 11 for the K line. Phenotypic response to selection is reduced over generations, but crossing of plateaued lines increased responses and realized heritabilities. Both realized heritabilities and heritabilities from residual maximal likelihood (REML) analyses were, in general, calculated from generation (−1)–44 (period 1), 45–70 (period 2) and 71–122 (period 3) separately. Realized heritabilities were in general smaller than heritabilities estimated from mixed model analysis. An overall estimate of heritability for NBA was found to be 0.19 (±0.01) by REML analysis. Additive variance is constant over all periods in the high line and the control line, but is reduced over periods in the low line. The reduction of additive variance in the low line could probably be explained by changes in gene frequencies. In all lines, environmental variances increased over periods. Inbreeding reduced the mean litter size by 0.72 (±0.10) pups per 10% increase in inbreeding, with substantial variance between periods and lines.

Summary 1Reproductive costs can affect survival and future reproduction. In winter and in short photoperiods, some individuals within populations of temperate-zone rodents inhibit reproduction and decrease food intake, while others do not. 2Two lines derived from a natural population of White-Footed Mice and selected to maintain or inhibit reproduction in short photoperiod were tested for two potentially correlated responses to selection: changes in food intake and body mass. Mice were raised to age 70 days in short or long photoperiod, following which testis size, body mass and food intake were measured over a 2-week period. 3In both lines and both photoperiods, there was an apparent response to selection in testis size and a correlated response to selection in food intake but not body mass. In both photoperiods, mice in the line selected for winter reproduction ate 50% more than mice in the line selected for winter reproductive inhibition. Mice in an unselected control line were intermediate for testis size and food intake. 4The increased food intake in a line of mice with a genetic tendency for winter reproduction suggests a potential cost of winter reproduction and a potential microevolutionary trade-off related to this cost of reproduction.

Transgenic alfalfa root cultures expressing sense and antisense barley hemoglobin transcripts were examined under varying levels of atmospheric oxygen. Root cultures overexpressing the hemoglobin gene (Hb+) maintained root growth when placed under 3% oxygen, whereas control cultures or cultures underexpressing hemoglobin (Hb-) experienced 30-70% declines in growth under the same conditions. ATP levels and ATP/ADP ratios for Hb+ lines did not significantly differ in 40 and 3% oxygen, whereas the ATP levels and ATP/ADP ratios in control and Hb- lines were significantly lower under 3% oxygen. Large increases in the production of nitric oxide (NO) were measured in root cultures grown under hypoxic conditions compared to aerobic conditions. The amount of NO accumulated in an Hb- line was 2.5-fold higher than that in the Hb+ line. Treatment of transgenic root lines under 40% oxygen with NO resulted in significant declines in the ATP levels and ATP/ADP ratio of an Hb- line and the control line, with no significant change in an Hb+ line. The root cell structure of an Hb- line showed evidence of cell breakdown under hypoxic growth, whereas an Hb+ line had no evidence of cell breakdown under similar growth conditions. These results lead us to hypothesize that NO is involved in the response of plants to hypoxia and that hemoglobin modulates the levels of NO in the hypoxic cell.

An artificial selection experiment was conducted for six generations to investigate the responses to selection for cadmium resistance in the least killifish, Heterandria formosa. There was a rapid response to selection. After only one generation of selection, two of the three selection lines had an increased resistance to cadmium, while all three selection lines had an elevated resistance by the next generation. After six generations of selection, fish from the selection lines survived about three times as long as control line fish when exposed to cadmium. Realized heritability for cadmium resistance was estimated to be 0.50. Cross-resistance to copper was studied in the F2, F3, and F6 generations; fish from the cadmium-resistant lines had a longer survival time than those from the control lines. Resistance to heat was investigated in the F2, F3, and F5 generations; the cadmium-resistant lines had a significantly shorter survival time than the control lines. Our results showed that evolution of resistance to cadmium was rapid, that cross-resistance to copper occurred, and that the evolution of resistance to cadmium was accompanied by a trade-off (fitness costs) as evidenced by the reduced heat tolerance.

To study the correlated evolution of locomotor behavior and exercise physiology, we conducted an artificial selection experiment. From the outbred Hsd:ICR strain of Mus domesticus, we began eight separate lines, each consisting of 10 breeding pairs. In four of the lines, we used within-family selection to increase voluntary wheel running. The remaining four lines were random-bred (within lines) to serve as controls. Various traits have been monitored to test for correlated responses. Here, we report on organ masses, with emphasis on the triceps surae muscle complex, an important extensor of the ankle. Mice from the selected lines exhibit reduced total body mass, increased relative (mass-corrected) kidney mass, and reduced relative triceps surae mass. In addition, a discrete muscle-mass polymor- phism was observed: some individuals had triceps surae that were almost 50% lighter than normal for their body mass. This small-muscle phenotype was observed in only three of the eight lines: in one control line, it has fluctuated in frequency between zero and 10%, whereas in two of the selected lines it has increased in frequency to approximately 50% by generation 22. Data from a set of parents and offspring (generations 23 and 24) are consistent with inheritance as a single autosomal recessive allele. Evidence for the adaptive significance of the small-muscle allele was obtained by fitting multiple-generation data to hierarchical models that include effects of genetic drift and/or selection. The small-muscle allele is estimated to have been present at low frequency (approximately 7%) in the base population, and analysis indicates that strong selection favors the allele in the selected but not control lines. We hypothesize that the small muscles possess functional characteristics and/or that the underlying allele causes pleiotropic effects (e.g., reduced total body mass; increased relative heart, liver, and kidney mass) that facilitate high levels of wheel running. Nevertheless, at generation 22, wheel running of affected individuals did not differ significantly from those with normal-sized muscles, and the magnitude of response to selection has been similar in all four selected lines, indicating that multiple genetic ''solutions'' are possible in response to selection for high activity levels.

Correlated responses in fitness and fertility traits were compared in transgenic and nontransgenic lines of mice selected for increased 8-week body weight. Two replicates of lines which either carried or did not carry the sheep metallothionein-1a sheep growth hormone transgene (oMt1a-oGH) were established. Host lines had been previously selected for rapid growth or selected randomly. Within-litter selection was carried out for 13 generations, and a randomly selected control line was kept for each set of replicate lines. Mice were genotyped every generation for the presence of the transgene, but this information was not used in selection decisions. The oMt1a-oGH construct was activated by adding 25 m m ZnSO₄ to the drinking water from 3 weeks (weaning) until 8 weeks of age. Zinc stimulation of the transgene was not carried out during mating, gestation and lactation. Correlated responses in fitness traits were measured by regression of least-squares means (as deviations from the control lines) on generation number. Two fitness indexes were defined to combine the information on individual fitness traits. The proportion of infertile matings was higher in generations 7 to 13 than in generations 0 to 6. Correlated responses to selection showed an increase in the cohabitation to littering interval in nontransgenic lines and an increase in litter sizes in lines from the selected background. Preweaning pup survival did not change over generations. Overall fitness increased in the transgenic line from the selection background whereas no changes were observed in the transgenic line from the control background. The initial frequency of 0.5 of the transgene was reduced to less than 0.10 in the selected background, but increased to an average of 0.62 in the control lines. The comparison of specific mating groups involving transgenic and nontransgenic mates revealed that the only consistent disadvantage in having a transgenic parent was the increase in the length of the cohabitation to littering interval. Major fitness problems were not associated with the oMt1a-oGH transgene, which makes this construct a potential choice for use in livestock breeding programmes.

A selection experiment for large adult weight based on individual performance was conducted for three generations in Helix aspersa aspersa. A second line was kept as an unselected control line. Direct response measured as deviation from the control line was 3.55 g after three generations of artificial selection, which averaged 13%. Realized heritability was 0.38 +/- 0.04. Correlated responses to selection showed a significant increase in weight after hibernation, mean egg weight and mean weight of newly-hatched snails with selection. For adult age, egg number, and hatching rate, no significant change correlated to selection was found, but this is to be confirmed.

The size and shape of the cockerel comb, ran be regarded as secondary sexual characters or sexual ornaments. Sexual characters are assumed to be costly to express and the expression of a secondary sexual character is suggested to be favourably correlated with the bearer's condition or fitness. The aim of this study was to clarify the effects of selection for male sexual characters, the correlated responses in other male traits and whether selection for sexual characters affects viability. Two selection lines (lines S and H) and a control line was used for 10 generations. Line S was selected for male comb size at 29 weeks of age and from generation six onwards, comb shape (the way the cockerel bear his comb) was added. Line H was selected for high concentration of hyaluronic acid (HA) in the comb at 28 weeks of age. The average number of animals of each sex and;election line was 560 and the randomly mated control line comprised an average of 150 animals of each sex per generation. Traits recorded an analysed were comb size (CS) and body weight (BW) at 29 weeks of age, comb shape (SH) at 32 weeks of age, comb weight (CW) after slaughter and mortality (M). In line S, the genetic and phenotypic trends increased for CS, CW and BW. Both CS and SH are traits involved in the impression of comb size as visualized by females during male choice and by males during male-male competition. With artificial upward selection for the male character CS (line S), CS, CW, BW and M also increased but SH was impaired. When adding SH to the selection criteria in line S, the negative generic trend for SH was changed to positive. As CS approaches its environmental limit, the heritability and genetic progress can be expected to decline. It seems that 10 generations of selection for increased CS is not enough to reach the environmental limit at which CS is expected to stabilize at an optimum size determined by natural selection. (Less)

Summary The data consisted of information on egg production traits (age at first egg, egg number and egg weight), and reproduction traits such as percentage fertile eggs (PF), percentage hatched of fertile eggs (PHF) and percentage hatched of total egg set (PHT) were also recorded for the selected parents. The experiment was carried out for 10 generations of selection for increased egg number (EN), egg weight (EW), egg mass (EM) along with a control line (C). Although line C had high PF, PHF and PHT in most generations compared to the selected lines, it was not significantly better than the EN and EM lines at the last generation. Differences in PF, PHF and PHT were also observed among the selected lines. The lowest performances of PF, PHF and PHT was observed in line EW. (Co)variances and resulting correlations were estimated between egg production and reproduction traits using a multivariate animal model. The result showed that the estimates of heritability values for egg production traits were moderate to high and low for reproduction traits. The genetic correlation between PF and egg weight traits in line EW was negative and positive in line EM. PHF was positively correlated with egg number in line EN and negatively correlated with egg weight in line EW. Genetic trends calculated from the animal model showed that direct selection for increased egg number in line EN, egg weight in line EW and egg mass in line EM has resulted in substantial genetic gain over generations. Moreover, in lines selected for egg number and egg mass there were consistent positive genetic trends of PHF and PHT along with the selected trait. Selection for increased egg weight, however, negatively affected PF, PHF and PHT over generations. Zusammenfassung Wird Reproduktion durch Selektion auf Legeleistung verschlechtert? Produktionsdaten waren Alter bei Legebeginn, Eizahl und Eigewicht, Reproduktion wurde durch %fruchtbarer Eier (PF) %Schlupf fruchtbarer Eier (PHF) und %Gesamtschlupf (PHT) bei selektierten Elterntieren erfasst. In drei Linien wurde durch 10 Generationen entweder auf Eizahl (EN), Eigewicht (EW) oder Eimasse (EM) selektiert und eine Kontollinie paralell vermehrt. Obwohl C uberlegen in Reproduktion war, fehlte statistische Signifikanz in Vergleich zu EN und EM in der letzten Generation. Die selektierten Linien unterschieden sich ebenfalls in Reproduktionseigenschaften, wobei diese in Linie EW am schlechtesten waren. (Co)Varianzen wurden mittels eines multivariaten Modells zwischen Produktions- und Reproduktionsmerkmalen geschatzt. Die genetische Korrelation zwischen EW und PF war in EW negativ aber positiv in EM. Heritabilitaten waren mittel bis hoch fur Produktions- und gering fur Reproduktionsmerkmale. PHF war mit Eizahl in der EN Linie positiv und negativ mit EW in der EW Linie korreliert. Die mittels Tiermodell geschatzten genetischen Trends zeigten erhebliche Gewinne bei direkt selektierten Merkmalen in den drei Linien und in Linien EN und EM konsistent positive Trends fur PHF und PHT, wahrend in Linie EW sich PF, PHF und PHT ungunstig veranderten.

Summary Inbreeding depression was estimated for four experimental Tribolium castaneum lines. Each line, containing approximately 7000 animals, was selected for 16 generations either randomly (control), on pupae weight (PWT), on family size (FST) or on an index containing both PWT and FST. The inbreeding trend was 0.9, 0.5, 0.5 and 0.4 % inbreeding per generation in PWT-selected, FST-selected, index-selected, and control line, respectively. The model used to estimate the inbreeding depression included a linear regression on individual inbreeding coefficients, and random additive genetic effects. Using all the performance and pedigree data, estimated inbreeding depressions in the control line were —0.13 (SE = 0.16; #) and —8.50 (SE = 2.66; μg) per 1 % inbreeding for FST and PWT, respectively. Using only performance data of the latest generation in the control line, the estimated inbreeding depressions changed considerably: —0.17 (SE = 0.82) and —37.4 (SE= 11.9) for FST and PWT, respectively. Estimated inbreeding depression for FST in the FST-selected line was — 0.40 (SE = 0.31). Inbreeding depression for PWT in the PWT-selected line was 21.6 (SE = 25.8). This study indicates that estimating inbreeding depression might best be based on the performance data of animals with an equal and sufficiently-large number of ancestral generations known. Zusammenfassung Wirkung von Datenstruktur und Selektion auf geschatzte Inzuchtdepression in experimentellen Triboleum castaneum Linien Jede der vier experimentellen Linien, aus je etwa 7000 Individuen, wurde durch 16 Generationen selektiert, zufallig die Kontrolle, auf Puppengewicht (PWT), Familiengrose (FST), oder auf einen beide Merkmale kombinierenden Index. Inzucntzuwachse in diesen vier Linien waren 0.4, 0.9, 0.5 und 0.5% je Generation. Das Modell zur Schatzung der Inzuchtdepression beinhaltete eine lineare Regression auf individuelle Inzuchtkoeffizienten und zufallige additive-genetische Wirkungen. Aus allen Daten, Leistung und Pedigree, ergaben sich —0.13 (SE = 0.16; #) und — 8.5 (SE = 2.66; mg) je 1% Inzucht fur FST und PWT, Daten der letzten Generation ergaben deutlich andere Werte: —0.17 (SE = 0.82) und —37.4 (SE = 11.9) fur FST und PWT. Inzuchtdepressionen fur FST bzw. PWT in den jeweils hierfur selektierten Linien waren —0.40 (SE = 0.31) und 21.6 (SE = 25.8). Es wird gefolgert, das Schatzungen auf Leistungen von hinreichend groser Zahl von Vorfahrengenerationen beruhen sollten.

The present study assessed the life spans in two lines of mice selectively bred for high (Turku Aggressive, TA) and low (Turku Nonaggressive, TNA) levels of aggression. The maintained parental Swiss albino strain (N), normally distributed with regard to aggression, served as a control line. It was found that the TNA males had a significantly shorter life span than the other lines of mice of both sexes. The relative early death of the TNA males was discussed in terms of male age-related decline of inherited low levels of catecholamine and androgenous hormone concentrations. © 1996 Wiley-Liss, Inc.

Populations of Brassica rapa were grown for three generations in each of two environments: intraspecific competition, with four surrounding Brassica rapa neighbors per pot, and interspecific competition, with two Raphanus sativus neighbors per pot. In each environment, the largest (by flower number) 10% of the plants were outcrossed and provided seeds for the next generation. As a control, a randomly chosen 10% of the plants in each environment were outcrossed to produce seed for the next generation. Each of these four treatments, the selected lines in intra- and interspecific competition and the corresponding control lines, was maintained for three generations. After a single generation of growth in a common, no-competition environment, replicate plants from each treatment were grown with no competition and with intra- and interspecific competition for determination of growth responses. After two generations of selection, flower number in the intraspecific-selection line had increased by more than 50% over that in the control line and by more than 19% over that under interspecific selection. After a common-environment generation, plants from the intraspecific-selection line were shown to have significantly faster growth in height and flower number as seedlings. Plants in the interspecific-selection line showed similar but nonsignificant trends. No differences in seed mass, emergence time, or photosynthetic rate were found between control and selected lines in either intra- or interspecific competition. Some differences between control and selected lines were noted in biomass allocation related to differences in phenology. The results demonstrate that performance in competitive environments can evolve through changes in plant development but that rates of evolution will differ in intra- and interspecific competition.

Summary Correlated responses in pituitary gland weight and growth hormone (GH) concentration in the serum and pituitary were studied in lines of mice selected for growth rate, and in controls. The selection criteria were weight gain between 28 and 38 days on an ad libitum feed intake (EPA line), or on intake restricted to 80% of the control mice (EPR line), and weight gain between 48 and 58 days under the above two feeding regimes (LPA and LPR lines). The control line was maintained by random breeding. In generation 13, pituitary weight and growth hormone levels were determined at 38 days in lines EPA, EPR and the control and at 58 days in lines LPA, LPR and the control. Pituitary weight, corrected for body weight gain, was smaller in the EPA line than in the control line at 38 days and was greater in the LPR line than in the control line at 58 days. There were large differences in serum GH concentrations between the selected lines and the control; the differences were statistically significant at 38 days, with the EPA and EPR lines having lower levels than the controls. Zusammenfassung Veranderung von Wachstumshormonspiegel bei Selektion fur Zuwachs bei Mausen Veranderungen im Hypophysengewicht und Wachstumshormon-(GH)-Konzentrationen im Serum und in der Hypophyse wurden bei Wachstumsselektionslinien und bei Kontrollmausen untersucht. Selektionskriterien waren Zuwachs zwischen 28 und 38 Tagen bei ad libitum Futteraufnahme (EPA Linie) oder bei Linien, wo Futteraufnahme auf 80% derjenigen der Kontrollmause (EPR Linie) begrenzt wurde und Zuwachs zwischen 48 und 58 Tagen unter beiden Futterweisen (LPA und LPR Linie). Die Kontrollinie wurde durch Zufallspaarung fortgepflanzt. In Generation 13 wurden Hypophysengewicht und Wachstumshormonspiegel im Alter von 38 Tagen in Linien EPA, EPR und in Kontrollen und bei 58 Tagen in Linien LPA und LPR und Kontrollen bestimmt. Hypophysengewicht, korrigiert fur Zuwachs, war geringer in der LPA Linie als in der Kontrolle bei 38 Tagen Alter und groser in der LPR Linie als in der Kontrolle bei 58 Tagen. Zwischen GH Konzentrationen selektierter und Kontrollinien waren erhebliche Differenzen, die bei 38 Tagen signifikant waren, wobei EPA und EPR Linien geringere Werte als die Kontrollen aufwiesen.

The effects of random response errors in amplitude and phase, element failures, and crosstalks on array gain and sidelobe level of ultrasonic transducer arrays are investigated by multivariate statistical analysis. The derived estimate equations are confirmed by simulation and measured data of various sonar arrays. The results show that the reasonable control limit of response errors for an infallible sidelobe reduction is not determined by the mean value of statistical sidelobes described in other papers but by the 95-percent control line proposed in this paper.

Alcoholics are almost invariably heavy users of tobacco. Both alcoholism and smoking appear to be influenced by genetic factors but it is not known whether the same or different genes regulate the abuse of ethanol and nicotine. Recent studies have demonstrated that the long-sleep (LS) and short-sleep (SS) mouse lines, which were selectively bred for differences in ethanol-induced anesthesia ("sleep-time"), also differ in several effects of nicotine and the muscarinic agonist, oxotremorine. In order to determine whether or not these differences are due to chance, the relative sensitivities of rat lines which were selectively bred for differences in ethanol-induced sleep-time were determined. The high alcohol sensitivity (HAS) rat line was more sensitive to the locomotor and body temperature depressant effects of nicotine than was the low alcohol sensitivity (LAS) rat line. The control line (CAS) was intermediate in sensitivity. The rat lines did not differ in sensitivity to oxotremorine's hypothermia-producing effects. The numbers and affinities of two classes of brain nicotinic receptors were measured in eight brain regions. No differences among the rat lines were detected. These results suggest that ethanol elicits some of its depressant actions via an effect on brain nicotinic systems, but the differences in sensitivity to ethanol and nicotine are probably not due to differences in the number of brain nicotinic receptors. Perhaps this interaction explains the high correlation between alcoholism and smoking in humans.

A Josephson timed regulator has been designed and tested which supplies timed bias current to logic gates, such as EX-OR and NOT gates. This regulator consists of four SQUIDs in series, where the output line is coupled twice to each SQUID. In addition, this output line functions as the SQUID control line. As a result, all SQUID junctions are able to simultaneously switch even if the junction critical current is scattered. This regulator is fabricated using Pb alloy technology, successfully tested, and then favorably compared with computer simulation results.

Several neonatal and adult parameters were determined in the Roderick-Wimer lines of mice selected for low (L) or for high (Hb and Hg) adult brain weight, and in the unselected control line (C). Neonatal cerebral weight, DNA (index of cell number), and protein were significantly higher in the H and C lines than in the L line. The ratios of cerebral DNA/weight (index of cell density), cerebral protein/weight, and cerebral protein/DNA (index of protein content per cell or cell size) were at birth practically the same in all lines. In the adult animals all the differences were amplified and, in addition, some of the differences in the above ratios were significant, for the cerebral cortex as well as for the cerebellum. These findings may be causally related to the reported superiority in behavioral performance of the H line.

Rates of depletion and half-lives of linoleic acid from epididymal, subcutaneous and retroperitoneal fat pads and the residual body were compared among 5 genetically diverse strains of mice: M16, a polygenic obese line developed by selection for high postweaning gain; ICR, a control line from which M16 was derived; H6, a nonobese strain selected for large 6-week body weight; L6, selected for small 6-week body weight; and C2 a control line from which H6 and L6 were initiated. Rates of depletion and half-lives of linoleic acid were obtained on a fat-free diet following an enrichment period of feeding a diet high in linoleic acid. The M16 mice have an increased capability of synthesizing fat from carbohydrates as shown by a continued increase in fat depot weights when fed the fat-free diet. The 4 other lines showed no subsequent increase in fat depot weights on the fat-free diet. Rates of depletion of linoleic acid were significantly different among lines in each of the 4 depots. Ranking of lines for depletion rates was similar among the 3 discrete depots, but a more rapid rate of depletion was observed in subcutaneous and retroperitoneal fat depots than in the epididymal fat depot. Rates of depletion in line M16 were slower than in the ICR control line. Line H6 had a slower rate of depletion than line L6. Line L6 deviated more from the C2 control than did line H6, indicating an asymmetric correlated selection response. The decreased depletion rate of linoleic acid in fat tissue of M16 and H6 mice suggests the possibility that the turnover rates of fatty acids have been reduced in these lines as a result of a reduction in lipolytic activity. The increased depletion rate of linoleic acid in L6 mice suggests that selection for small body size has substantially increased the rate of fat turnover. The experiment demonstrates that genetic differences among lines in fat turnover have accurued as corelated responses to selection for growth rate.

From a pool of primary rat embryo fibroblast cells, three lines—two SV40-infected and one control—were serially propagated. Prior to unequivocal morphological evidence of transformation, increased sensitivity to vesicular stomatitis virus (VSV) was found in the two SV40-infected lines when compared to the control line. The increased VSV sensitivity of the transformed cells seems to be due to a diminished production of and sensitivity to interferon, and not to differences in adsorption. When a collection of diverse transformed cell lines were also compared with arbitrarily selected control cell populations, the majority of the transformed cells also exhibited enhanced VSV sensitivity. Lines transformed by methylcholanthrene also featured this property. The data suggest that diminished sensitivity to and production of interferon is an early consequence of infection by oncogenic viruses, and a property that persists in many lines of transformed cells.