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[The genetic analysis of amplitude of progesterone secretion in serial blood collection from tail in min sows].

28 adult Min sows (3-7 parities), represented 9 sire families were selected to conduct the continual blood collection from the tail for two hours at the interval of ten minutes between 9:00-11:00 in the morning on the sixth day after the last mating. The content of progesterone was assayed by radio-immunological assay. The amplitudes of the secretion of progesterone were generated by the procedure of HORM fft. exe complied by the author. It is difficult to get a reasonable conclusion from the content analysis, because the content varied widely between different points of blood collection in single sow. After Fourier conversion, the heritability of amplitude for the fifth partial wave was high (h2 = 0.932); middle for the basal, 2nd and 3rd partial waves; lower for others. This supported the idea that prolific sows had more active secretion of progesterone in luteal cells. The coexist of low and high heritability components in amplitude of progesterone secretion showed that the activities of progesterone secretion were influenced by both the genetics and environments. The genetic correlation of basal, 1st, 5th partial waves were negative, the others were positive, with the litter size and litter size alive. It showed that the reproductive performance of Min pigs were not expressed perfectly, as the balance of secretion of progesterone did not reach the best. The genetic correlation of all partial waves with duration of estrus was negative which supported that the progesterone suppresses the estrus. The genetic correlation of 3rd, 5th partial waves were stronger than others, but selection for 5th partial wave would make high responses than the 3rd wave, because the genetic correlation of 3rd partial wave with litter size and litter size alive was positive, therefore, the more appropriats method of selection for progesterone was adopted, the better results would be achieved in the improvement of indirect selection response for litter size.

Animals↗

Genetic parameters of bovine serum immunoglobulins.

Radial immunodiffusion techniques were used to determine serum concentrations of immunoglobulins G1, G2, M, and A in 1,293 daughters of 282 Holstein-Friesian sires from 31 herds in southwestern Ontario, Canada. Mean serum immunoglobulin concentrations (mg/100 ml) were 2,163, 2,409, 531, and 107 for immunoglobulins G1, G2, M, and A, respectively. Herd effects were significant for all four immunoglobulin isotypes. Age of cow effects were significant for immunoglobulins G1 and G2 only. Both immunoglobulins G1 and G2 increased with age, but the rate of increase of G2 was twice that of G1. Stage of lactation had a significant effect on G2 and M. Immunoglobulin G2 was highest in the first 200 d post-calving and immunoglobulin M was highest late in lactation and during the dry period. Paternal half-sib heritabilities for immunoglobulins G1, G2, M, and A were .10, .10, .09, and .14, respectively. Genetic correlations among the four immunoglobulin isotypes ranged from .49 to 1.02. Genetic correlations between immunoglobulin G2 and 305-d milk and fat yields were .36 and .13 and between immunoglobulin A and 305-d milk and fat yields were .37 and .63. Genetic correlations between immunoglobulin M and milk and fat production were negative (-.83 and -.34). Phenotypic correlations between immunoglobulin isotypes were low except for the correlation between immunoglobulins G1 and G2, which was .36.

Age Factors↗

The genetics of phenotypic plasticity. IX. Genetic architecture, temperature, and sex differences in Drosophila melanogaster.

We examined the genetic architecture of plasticity of thorax and wing length in response to temperature in Drosophila melanogaster. Reaction norms as a function of growth temperature were analyzed in 20 isofemale lines in a natural population collected from Grande Ferrade near Bordeaux (southern France) in two different years. We found evidence for a complex genetic architecture underlying the reaction norms and differences between males and females. Reaction norms were negative quadratics. Genetic correlations were moderately high between traits within environments. Among characteristic values, the magnitudes of genetic correlations varied among traits and sexes. We hypothesized that genetic correlations among environments would decrease as temperatures became more different. This expectation was upheld for only one trait, female thorax length. For males for both traits, the correlations were large for both very similar and very different temperatures. These correlations may constrain the evolution of the shape of the reaction norms. Whether the extent of independence implies specific regulatory genes or only a specific allelic regulation of trait genes can not be decided from our results.

Animals↗

A behavior genetic investigation of the relationship between leadership and personality.

Phenotypic research on leadership style has long considered the importance of individual differences in personality when identifying the behaviors associated with good leaders. Although leadership and many personality traits have been separately shown to be heritable, these constructs have not been examined with genetically informative data to identify common sources of heritability in the two domains. A logical extension to current research, therefore, is to examine the extent to which factors of personality are predictive of leadership dimensions and the extent to which unique genetic contributions to the relationship between personality and leadership style may be identified. Adult twin pairs (183 MZ and 64 same-sex DZ) completed the Multifactor Leadership Questionnaire (MLQ) and the Personality Research Form (PRF). Univariate analyses indicated that both leadership factors (transformational and transactional leadership) and all five of the "Big Five" factors (openness, conscientiousness, extraversion, disagreeableness, and neuroticism) were best fit by genetic models. Multivariate genetic analyses suggest that transformational leadership shows a statistically significant positive genetic correlation with conscientiousness, extraversion, and openness to experience. Transactional leadership shows a significant negative genetic correlation with conscientiousness and extraversion, and a significant positive genetic correlation with disagreeableness. These results underscore the importance of conscientiousness and extraversion in predicting leadership style, and illustrate important differences between transformational and transactional leaders.

Adult↗

Investigation of three strategies for an international genetic evaluation of beef cattle weaning weight.

Weaning weights from 83,389 Limousin calves born between 1993 and 2002 in France and the Trans-Tasman block (Australia/New Zealand) were analysed to compare different strategies for running an international genetic evaluation for the breed. These records were a subset of the complete data for both countries and comprised a sample of herds that had recorded progeny of sires used across both countries. Genetic and phenotypic parameters for weaning weight were estimated within the countries. The estimates of direct genetic heritabilities were higher in France than in the Trans-Tasman block (0.31 vs. 0.22), while direct-maternal genetic correlations were less negative in the Trans-Tasman block (-0.10) than in France (-0.21). Different strategies for an international evaluation were studied, and the correlations between the estimated breeding values (EBV) of national evaluations and these strategies were derived. The international evaluation strategies were a) an animal model on raw performance data with non unity genetic correlations and heterogeneous residual and genetic variances across countries; b) the same animal model applied to pre-corrected (for fixed effects) performance data; and c) a sire model on de-regressed proofs (MACE). Estimates of the genetic correlations between weaning weight in both countries were 0.86 (0.80) for direct (maternal) genetic effects for the first strategy. Estimation of variance components by MACE appeared to be very sensitive to the sample of bulls and their reliability approximations. Variance component estimates obtained using pre-corrected data were inconsistent with estimates on raw data. However, the EBV predicted using pre-corrected data and parameters estimated from the raw data were similar to those predicted from raw data. Correlations between national and international EBV were always high (> 0.90) for sires, whichever genetic effect (direct or maternal) or international evaluation model was considered. The ranking of the bulls in the top 100 is of primary interest in terms of international genetic evaluation. In this study, some re-ranking of sires was observed for the top 100 bulls between countries and between the three international evaluation models. Thus, the origin of top sires may vary according to the implemented international evaluation strategy.

Algorithms↗

Genetic parameters for testosterone production in boars.

Data were collected in 1982 through 1989 from 66 sires and 358 Duroc boars. Testosterone production was measured from peripheral blood samples before (PRE) and after (POST) GnRH challenge. Additionally, data were collected on testes length at 168 d (TL168), testes width at 168 d (TW168), testes volume at 168 d (TVOL), birth weight (BWT), average daily gain (ADG), days to 104 kg (DAYS104), and backfat adjusted to 104 kg (FAT). Overall means for these traits were 24.6 ng.ml-1.h-1, 75.7 ng.ml-1.h-1, 12.3 cm, 11.6 cm, 422.0 cm3, 1.5 kg, .5 kg, 189.3 d, and 18.5 mm, respectively. Son-sire regressions were used to calculate genetic parameters. Heritabilities for PRE, POST, TL168, TW168, TVOL, BWT, ADG, DAYS104, and FAT were .37, .26, .33, .34, .33, .21, .42, .35, and 0, respectively. Moderately favorable genetic correlations were obtained for PRE and POST with growth measurements. Large positive genetic correlations were present for both PRE and POST with TL168, TW168, and TVOL, and testes measurements had large positive genetic correlations with growth traits. Selection for testes size or testosterone production should be equally effective. However, it seems that selection for testes size would result in larger changes in measures of growth than selection for testosterone. This study suggests that testes measurements are good predictors of both basal and challenge testosterone levels. Selection for increased testis size or increased testosterone levels would be expected to enhance growth.

Adipose Tissue↗

The genetic overlap between schizophrenia and major depression with cognitive function.

This study aimed to systematically dissect the shared genetic basis of schizophrenia (SCZ) and major depression (MD) with cognitive function. To investigate this, we integrated large-scale genome-wide association studies (GWAS) summary statistics for SCZ (N = 175,799, [cases, 74,776; controls, 101,023]), MD (N = 2,622,273 [cases, 550,355; controls, 2,071,918]) and four cognitive traits (reaction time, N = 330,069; memory, N = 112,067; verbal-numerical reasoning, N = 36,035; educational attainment, N = 111,114). Linkage disequilibrium (LD) score regression analysis revealed that SCZ showed significant negative genetic correlations with reaction time, memory, and verbal-numerical reasoning. MD showed negative genetic correlations with memory, verbal-numerical reasoning, and educational attainment. Bayesian colocalization analysis identified seven genomic regions with strong or supportive evidence between SCZ and cognitive function, and two genomic regions with supportive evidence between MD and cognitive function. Gene mapping and over representation analysis (ORA) indicated that SCZ-associated genes were primarily involved in pathways related to transport processes, and MD-associated genes were significantly enriched in pathways related to neural development. Through genetic correlation and colocalization analysis, this study elucidates the genetic overlap between SCZ and MD with cognitive function, providing a new perspective for related research.

Journal Article↗

Heritability of test day somatic cell counts and its relationship with milk yield and protein percentage in dairy ewes.

A total of 6620 monthly test day records of SCC, milk yield, and protein percentage from single lactations of 2374 Spanish Churra ewes from 10 flocks was used to estimate genetic and environmental parameters. A subset of 4278 records containing data from healthy udders (SCC < or = 250,000 cells/ml) was also analyzed. Genetic parameters were estimated by REML using an animal model. Herd test date, parity, and lactation stage contributed significantly to variation of most variables, and birth type significantly affected milk yield only. The SCC increased markedly as parity number and stage of lactation increased. Heritabilities (+/- SE) for test day milk yield, log SCC, protein percentage, and log SCC (< or = 250,000 cells/ml) were 0.18 (0.03), 0.09 (0.02), 0.16 (0.03), and 0.03 (0.02), respectively. The corresponding repeatabilities were 0.54, 0.38, 0.38, and 0.10. Genetic correlations of log SCC with milk yield and protein percentage were -0.23 and 0.18, respectively. Phenotypic correlations were -0.15 and 0.16. Genetic and environmental reduction of SCC for dairy ewes could be achieved using practices similar to those for dairy cows. The negative genetic correlation between milk yield and SCC suggested that selection for increased milk yield alone is expected to result in a decrease in SCC.

Animals↗

Association of heifer fertility with cow fertility and yield in dairy cattle.

Genetic correlations of heifer fertility and first-parity yield usually were negative and opposite in sign from genetic correlations of first-parity fertility and yield. Most estimates of genetic correlation between heifer and first-parity fertility were not significantly different from zero. Increasing yield may improve genetic potential for fertility, but stress of increased yield may overcome genetic potential for improved fertility. Days open and 305-day yield for first parity were considered with index selection; sires were evaluated on daughter performance. Days open had a small influence on the selection index; genetic gains in days open for first parity were largely offset by correlated losses in service period for heifers. Restricted index selection, holding days open constant, required considerable economic importance of days open.

Animals↗

Genomic meta-analyses of binge-eating behavior and anorexia nervosa yield insights into the unique and shared biology of eating disorder phenotypes.

Eating disorders-including anorexia nervosa (AN), bulimia nervosa and binge-eating disorder-are clinically distinct but exhibit symptom overlap and diagnostic crossover. Genomic analyses have mostly examined AN. Here we conducted a genomic meta-analysis of case-control studies of binge-eating behavior (BE; 39,279 cases, 1,227,436 controls), alongside analyses of AN (24,223 cases, 1,243,971 controls) and its subtypes (all European ancestries). We identified six BE-associated loci, including loci associated with a higher body mass index and impulse-control behaviors. AN genome-wide association studies yielded eight loci, validating six loci. Subsequent polygenic risk score analysis demonstrated an association with AN in two East Asian ancestry studies. BE and AN exhibited similar positive genetic correlations with psychiatric disorders but opposing genetic correlations with anthropometric traits. Most of the genetic signal in BE and AN was not shared with body mass index. We have extended eating disorder genomics beyond AN; future work will incorporate multiple diagnoses and global ancestries.

Behavioural genetics↗

Genome-wide association studies of binge eating behaviour and anorexia nervosa yield insights into the unique and shared biology of eating disorder phenotypes.

Eating disorders -including anorexia nervosa (AN), bulimia nervosa, and binge eating disorder-are clinically distinct but exhibit symptom overlap and diagnostic crossover. Genomic analyses have mostly examined AN. We conducted the first genomic meta-analysis of binge eating behaviour (BE; 39,279 cases, 1,227,436 controls), alongside new analyses of AN (24,223 cases, 1,243,971 controls) and its subtypes (all European ancestries). We identified six loci associated with BE, including loci associated with higher body mass index (BMI) and impulse-control behaviours. AN GWAS yielded eight loci, validating six loci. Subsequent polygenic risk score analysis demonstrated an association with AN in two East Asian ancestry cohorts. BE and AN exhibited similar positive genetic correlations with psychiatric disorders, but opposing genetic correlations with anthropometric traits. Most of the genetic signal in BE and AN was not shared with BMI. We have extended eating disorder genomics beyond AN; future work will incorporate multiple diagnoses and global ancestries.

Journal Article↗

Genetic parameter estimates for reproductive traits of male and female littermate swine.

Reproductive traits of purebred and crossbred pigs produced in a four-breed diallel mating system using the Duroc, Landrace, Spotted and Yorkshire breeds were collected for five consecutive farrowing seasons (two farrowing seasons/year) beginning in fall 1976. Paternal half-sib heritabilities and genetic correlations for testicular traits (120 boars from 36 sires), serum testosterone (TE) and luteinizing hormone (LH) concentrations before and after treatment with gonadotropin releasing hormone (GnRH; 131 boars from 37 sires) and breeding performance traits (151 boars from 38 sires) were estimated. Heritability estimates were generally small to moderate except for sperm/gram testis (SGT), LH concentrations before (LHO) and at 3 h (LH3) after treatment with GnRH (.73 +/- .48, .61 +/- .46 and 1.19 +/- .45, respectively). A large positive genetic correlation was found for LHO with LH3 (.94 +/- .39), while a negative relationship existed for LH3 with TE concentrations at 3 h after GnRH injection. The genetic correlation between a boar's average first service conception rate and average conception rate also was significant (.82 +/- .54). Genetic correlations among littermate traits would suggest that selection for decreased age at puberty in gilts could cause an increase in LH concentrations in boar offspring, before and after GnRH injection, and may also have adverse effects on their ability to settle females. Selection for increased weight at puberty of gilts could cause TE concentrations of boar offspring to increase while having little effect on their breeding performance.

Animals↗

Genetic parameters for yield traits of cows treated or not treated with bovine somatotropin.

The objective of this study was to estimate genetic correlations between yield traits of cows treated with bovine somatotropin (bST) and the same yield traits of untreated cows. Lactation records from registered Holstein cows were divided by parity into 3 data sets: 1, 2, and 3 through 5. Approximately 10% of the records in each data set were from cows treated with bST. The numbers of records of treated and untreated cows in the data sets were 4,337 and 48,765; 3,730 and 37,796; and 3,645 and 33,957. Two-trait animal models (records for cows treated or not treated) were used to estimate genetic parameters for milk production traits and somatic cell score (SCS). Estimates of heritability for milk yield for records of treated and untreated cows for the 3 data sets were 0.13, 0.16, and 0.09, and 0.18, 0.18, and 0.14, respectively, with estimates of repeatability of 0.50 and 0.41 for data set 3. Estimates of heritability for fat yield for records of treated and untreated cows were 0.31, 0.16, and 0.12, and 0.27, 0.21, and 0.16. Estimates of repeatability were 0.50 and 0.43 for data set 3. Heritability estimates for protein yield for records of treated and untreated cows were 0.13, 0.17, and 0.12, and 0.20, 0.23, and 0.16, with estimates of repeatability of 0.52 and 0.47. Estimates of heritability for SCS for treated and untreated cows were 0.08, 0.15, and 0.13, and 0.11, 0.13, and 0.13 with repeatability estimates of 0.52 and 0.45. Estimates of genetic correlations between milk yields with and without bST treatment in lactations 1, 2, and 3 to 5 were all 0.99. Estimates of genetic correlations for fat and protein yields were 0.96 for all data sets. Estimates for SCS were 0.99. Estimates of genetic correlations between records of treated and untreated cows were large enough to conclude that records of treated and untreated cows could be considered to be one trait, with treatment as a fixed effect to account for differences in means.

Animals↗

Utility of genetic markers in the study of human resemblance.

A method for the estimation of genetic correlations based upon analysis of genetic marker phenotypes is presented. At a given marker locus, the probability of observing a pair of individuals with a specific combination of phenotypes can be expressed as a function of the gene frequencies at that locus and the genetic correlation (R) between that pair. The likelihood of obtaining a sample of n such pairs with their phenotypes at m marker loci can be expressed as a product of nm such functions. From the likelihood function, maximum likelihood estimates of R can be obtained, and hypotheses about R may be tested. A sample of Swedish twin families (61 dizygotic twin pairs, 268 husband-wife pairs, and 164 sib pairs) were analyzed by this method using information from 21 markers. It was found that for the twin pairs, R = 0.458, which was significantly different from the R calculated for sib pairs (R = 0.558) but not significantly different from the expected 0.5. for the husband-wife pairs, it was found that R = 0.086, which did differ significantly from the expected value of 0, indicating the presence of nonrandom mating in this population.

Adult↗

Genetic parameters of lactation cell counts and milk and protein yields in dairy ewes.

A total of 3231 lactation records of somatic cell counts (SCC), milk yield, and protein percentage for 2379 Spanish Churra ewes from 10 flocks were used to estimate genetic and environmental parameters. Genetic parameters were estimated by REML with a multitrait repeatability animal model. A lactation measure of SCC was obtained as the mean of test day log SCC adjusted for stage of lactation. Heritabilities for SCC, milk yield, and protein percentage were 0.12, 0.24, and 0.17, respectively. The corresponding repeatabilities were 0.35, 0.49, and 0.38. Heritability and repeatability estimates of SCC obtained from this study fell within the range frequently reported for dairy cows. Therefore, as practiced for dairy cattle, future possibilities for sire evaluation to improve udder health status using lactation measures of SCC for dairy sheep are not rejected, although hygienic practices are regarded as more important. Genetic correlations of SCC with milk yield and protein percentage were -0.15 and -0.03, respectively. The genetic correlation between milk yield and protein percentage was -0.47. The low genetic correlations of SCC with milk yield and protein percentage may indicate that breeding decisions to improve milk and protein yields of Churra ewes are not expected to have an effective correlated response in SCC.

Analysis of Variance↗

Spirometric performance in Belgian Blue calves: II. Analysis of environmental factors and estimation of genetic parameters.

Genetic parameters and environmental effects for spirometric variables (SV) in calves were estimated using 734 Belgian Blue calves (15 to 297 d of age), sired by 20 AI bulls. For each calf, the following SV were measured: 1) the average ventilation (l/min) recorded during the 15 s of maximal ventilatory changes induced by lobeline administration (0.25 mg/kg, i.v.) (15-s MV(L)); 2) the vital capacity, and the maximal peak expiratory and inspiratory flows recorded after lobeline administration; and 3) the ventilatory reserve (15-s MV(L) - ventilation at rest). Analysis of environmental factors showed age of calf, herd, sex, and vaccination status had significant effects on SV. A sire model and a multiple-trait derivative-free REML procedure were used to estimate genetic parameters for SV, body weight, and muscling score. Heritabilities for SV ranged from 0.28 +/- 0.11 to 0.44 +/- 0.16. Genetic correlations among SV varied from 0.76 to 0.98 and environmental correlations from 0.69 to 0.80. Genetic correlations of SV with body weight (0.25 to 0.56) and with muscling score (0.21 to 0.76) were positive, as were environmental correlations of SV with body weight (0.44 to 0.70) and muscling score (0.09 to 0.25). These results suggest that selection may improve SV without impairing other traits of economic importance.

Animals↗

Genetic and phenotypic relationships among locomotion type traits, profit, production, longevity, and fertility in Spanish dairy cows.

The phenotypic and genetic relationships of 3 locomotion traits with profit, production, longevity, and fertility traits were studied to determine the importance of locomotion traits for dairy producers. Two data sets including official milk records and type classification scores of 62,293 cows, and reproductive records of 24,561 cows from the Basque and Navarra Autonomous Regions were analyzed. Higher scores for feet and legs (FL), foot angle (FA), and rear legs set (RLS) were positively related to production and functional traits, whereas fertility was not significantly affected. The cows that scored the highest for FL were $213/yr more profitable, produced 575 kg more milk per year, and remained in the herd for 307 more functional days than the cows scoring the lowest. Feet and legs was the trait most genetically correlated to profit, although a low value (0.10) was obtained, whereas RLS was the trait most correlated to milk production (0.12). Genetic correlations among FL, FA, RLS, and longevity traits (from -0.10 to 0.05) were low. Quadratic curves were the best fit for both profit and functional herd life for EBV of each of the 3 locomotion traits. Further studies dealing with profitability and lameness, instead of using conformation traits, could be performed directly if a larger data pool of lameness was routinely recorded.

Animals↗

Factors influencing international comparisons of dairy sires.

A method of dairy sire evaluation across multiple countries is described. Factors influencing this method are overestimation of genetic trends within countries, inclusion of evaluations of imported bulls, years of birth of the bulls included in the analysis, and estimates of genetic correlations between countries. Fall 1994 evaluations for milk, fat, and protein yields from Canada (4559 bulls), Germany (5894 bulls), and France (8419 bulls) were used to study the effect of these factors. After inclusion of ancestors there were 21,555 bulls in total. Eight data files were created based on combinations of three factors: 1) bulls born from 1970 to present versus bulls born from 1979 to present, 2) all bulls included versus imported bulls omitted, and 3) official Canadian evaluations for all lactations versus Canadian evaluations for first lactation only. Separate evaluations for two of the data files assumed a uniform genetic correlation of 0.995 between countries. Rankings of top bulls from analyses were affected by all factors to various degrees, depending on the country. Evaluations of imported bulls have an effect on bull rankings and probably should not be included. An assumed uniform genetic correlation between countries of 0.995 may not be appropriate. Proper methods and data for estimation of the genetic correlation between countries should be sought.

Animals↗