Breeding selection
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Browsers represent a challenge for breeding facilities because of their sensitivity to nutritional management. Western Derby eland (Tautrotragus derbianus derbianus, WDE) is a large browsing antelope with a very diverse diet. Because of its critically endangered status, a small WDE population is kept for conservation purposes in the fenced Fathala reserve (Senegal) and during the critical, hot dry season, the animals are offered supplementary Acacia albida pods. We aimed to identify which woody plant species were preferentially selected/avoided by WDE during the period of food shortage, which plant nutritional properties were drivers of animals' diet selection, and how this selectivity was affected by supplemental feed. The animals were selective for certain plant species, most for Piliostigma thonningi pods. Preferences decreased with a feed supplement, while avoidances remained intact. Diet selection was connected with chemical traits, mostly by negative correlations to N, Mg, Ca and hemicellulose, which disappeared or were weaker when supplemental feed was offered. Our findings indicate that large browsers during periods of food shortage must cope with inappropriate chemical composition in regard to nutrition and seek to alleviate them not only by diversification of plant species in the diet, but also by adjusting chemical diet quality as a whole.
- MeSH
- antilopy fyziologie MeSH
- chov MeSH
- dieta * MeSH
- fyziologický stres MeSH
- fyziologie výživy zvířat MeSH
- krmivo pro zvířata analýza klasifikace MeSH
- ohrožené druhy MeSH
- preference v jídle * MeSH
- rostliny klasifikace metabolismus MeSH
- zachování přírodních zdrojů metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Senegal MeSH
Banana (Musa spp.) is an important crop in the African Great Lakes region in terms of income and food security, with the highest per capita consumption worldwide. Pests, diseases and climate change hamper sustainable production of bananas. New breeding tools with increased crossbreeding efficiency are being investigated to breed for resistant, high yielding hybrids of East African Highland banana (EAHB). These include genomic selection (GS), which will benefit breeding through increased genetic gain per unit time. Understanding trait variation and the correlation among economically important traits is an essential first step in the development and selection of suitable GS models for banana. In this study, we tested the hypothesis that trait variations in bananas are not affected by cross combination, cycle, field management and their interaction with genotype. A training population created using EAHB breeding material and its progeny was phenotyped in two contrasting conditions. A high level of correlation among vegetative and yield related traits was observed. Therefore, genomic selection models could be developed for traits that are easily measured. It is likely that the predictive ability of traits that are difficult to phenotype will be similar to less difficult traits they are highly correlated with. Genotype response to cycle and field management practices varied greatly with respect to traits. Yield related traits accounted for 31-35% of principal component variation under low and high input field management conditions. Resistance to Black Sigatoka was stable across cycles but varied under different field management depending on the genotype. The best cross combination was 1201K-1xSH3217 based on selection response (R) of hybrids. Genotyping using simple sequence repeat (SSR) markers revealed that the training population was genetically diverse, reflecting a complex pedigree background, which was mostly influenced by the male parents.
- MeSH
- banánovník genetika MeSH
- fenotyp MeSH
- genetická variace * MeSH
- genom rostlinný MeSH
- genomika MeSH
- genotyp MeSH
- lokus kvantitativního znaku genetika MeSH
- mikrosatelitní repetice genetika MeSH
- populační genetika * MeSH
- selekce (genetika) * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Afrika MeSH
BACKGROUND: Understanding the mechanisms and selective forces leading to adaptive radiations and origin of biodiversity is a major goal of evolutionary biology. Acrocephalus warblers are small passerines that underwent an adaptive radiation in the last approximately 10 million years that gave rise to 37 extant species, many of which still hybridize in nature. Acrocephalus warblers have served as model organisms for a wide variety of ecological and behavioral studies, yet our knowledge of mechanisms and selective forces driving their radiation is limited. Here we studied patterns of interspecific gene flow and selection across three European Acrocephalus warblers to get a first insight into mechanisms of radiation of this avian group. RESULTS: We analyzed nucleotide variation at eight nuclear loci in three hybridizing Acrocephalus species with overlapping breeding ranges in Europe. Using an isolation-with-migration model for multiple populations, we found evidence for unidirectional gene flow from A. scirpaceus to A. palustris and from A. palustris to A. dumetorum. Gene flow was higher between genetically more closely related A. scirpaceus and A. palustris than between ecologically more similar A. palustris and A. dumetorum, suggesting that gradual accumulation of intrinsic barriers rather than divergent ecological selection are more efficient in restricting interspecific gene flow in Acrocephalus warblers. Although levels of genetic differentiation between different species pairs were in general not correlated, we found signatures of apparently independent instances of positive selection at the same two Z-linked loci in multiple species. CONCLUSIONS: Our study brings the first evidence that gene flow occurred during Acrocephalus radiation and not only between sister species. Interspecific gene flow could thus be an important source of genetic variation in individual Acrocephalus species and could have accelerated adaptive evolution and speciation rate in this avian group by creating novel genetic combinations and new phenotypes. Independent instances of positive selection at the same loci in multiple species indicate an interesting possibility that the same loci might have contributed to reproductive isolation in several speciation events.
- MeSH
- biodiverzita MeSH
- biologická evoluce MeSH
- fenotyp MeSH
- genetická variace MeSH
- hybridizace genetická MeSH
- pohlavní chromozomy * MeSH
- reprodukční izolace MeSH
- selekce (genetika) * MeSH
- tok genů * MeSH
- vznik druhů (genetika) MeSH
- zpěvní ptáci genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
Here, we perform cross-generational GS analysis on coastal Douglas-fir (Pseudotsuga menziesii), reflecting trans-generational selective breeding application. A total of 1321 trees, representing 37 full-sib F1 families from 3 environments in British Columbia, Canada, were used as the training population for (1) EBVs (estimated breeding values) of juvenile height (HTJ) in the F1 generation predicting genomic EBVs of HTJ of 136 individuals in the F2 generation, (2) deregressed EBVs of F1 HTJ predicting deregressed genomic EBVs of F2 HTJ, (3) F1 mature height (HT35) predicting HTJ EBVs in F2, and (4) deregressed F1 HT35 predicting genomic deregressed HTJ EBVs in F2. Ridge regression best linear unbiased predictor (RR-BLUP), generalized ridge regression (GRR), and Bayes-B GS methods were used and compared to pedigree-based (ABLUP) predictions. GS accuracies for scenarios 1 (0.92, 0.91, and 0.91) and 3 (0.57, 0.56, and 0.58) were similar to their ABLUP counterparts (0.92 and 0.60, respectively) (using RR-BLUP, GRR, and Bayes-B). Results using deregressed values fell dramatically for both scenarios 2 and 4 which approached zero in many cases. Cross-generational GS validation of juvenile height in Douglas-fir produced predictive accuracies almost as high as that of ABLUP. Without capturing LD, GS cannot surpass the prediction of ABLUP. Here we tracked pedigree relatedness between training and validation sets. More markers or improved distribution of markers are required to capture LD in Douglas-fir. This is essential for accurate forward selection among siblings as markers that track pedigree are of little use for forward selection of individuals within controlled pollinated families.
- MeSH
- genomika MeSH
- lineární modely MeSH
- modely genetické MeSH
- Pseudotsuga genetika růst a vývoj MeSH
- šlechtění rostlin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Britská Kolumbie MeSH
A plant selection system based on the phosphomannose isomerase gene (pmi) as a selectable marker is often used to avoid selection using antibiotic resistance. Nevertheless, pmi gene is endogenous in several plant species and therefore difficult to use in such cases. Here we evaluated and compared Agrobacterium-mediated transformation of Linum usitatissimum breeding line AGT-952 (without endogenous pmi gene) and Nicotiana tabacum var. WSC-38 (with endogenous pmi gene). Transformation was evaluated for vectors bearing transgenes that have the potential to be involved in improved phytoremediation of contaminated environment. Tobacco regenerants selection resulted in 6.8% transformation efficiency when using a medium supplemented with 30 g/L mannose with stepwise decrease of the sucrose concentration. Similar transformation efficiency (5.3%) was achieved in transformation of flax. Relatively low selection efficiency was achieved (12.5% and 34.8%, respectively). The final detection of efficient pmi selection was conducted using PCR and the non-endogenous genes; pmi transgene for flax and todC2 transgene for tobacco plants.
- MeSH
- Agrobacterium genetika MeSH
- bakteriální transformace genetika MeSH
- biodegradace MeSH
- geneticky modifikované rostliny genetika MeSH
- kultivační média chemie MeSH
- len účinky léků genetika MeSH
- mannosa-6-fosfátisomerasa genetika MeSH
- mannosa metabolismus farmakologie MeSH
- selekce (genetika) MeSH
- tabák účinky léků genetika MeSH
- Publikační typ
- časopisecké články MeSH
When individuals breed more than once, parents are faced with the choice of whether to re-mate with their old partner or divorce and select a new mate. Evolutionary theory predicts that, following successful reproduction with a given partner, that partner should be retained for future reproduction. However, recent work in a polygamous bird, has instead indicated that successful parents divorced more often than failed breeders (Halimubieke et al. in Ecol Evol 9:10734-10745, 2019), because one parent can benefit by mating with a new partner and reproducing shortly after divorce. Here we investigate whether successful breeding predicts divorce using data from 14 well-monitored populations of plovers (Charadrius spp.). We show that successful nesting leads to divorce, whereas nest failure leads to retention of the mate for follow-up breeding. Plovers that divorced their partners and simultaneously deserted their broods produced more offspring within a season than parents that retained their mate. Our work provides a counterpoint to theoretical expectations that divorce is triggered by low reproductive success, and supports adaptive explanations of divorce as a strategy to improve individual reproductive success. In addition, we show that temperature may modulate these costs and benefits, and contribute to dynamic variation in patterns of divorce across plover breeding systems.
- MeSH
- biologická evoluce * MeSH
- Charadriiformes fyziologie MeSH
- chov MeSH
- párová vazba MeSH
- rozmnožování fyziologie MeSH
- rozvod MeSH
- sexuální chování zvířat fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
KEY MESSAGE: This work discusses several selected topics of plant genetics and breeding in relation to the 150th anniversary of the seminal work of Gregor Johann Mendel. In 2015, we celebrated the 150th anniversary of the presentation of the seminal work of Gregor Johann Mendel. While Darwin's theory of evolution was based on differential survival and differential reproductive success, Mendel's theory of heredity relies on equality and stability throughout all stages of the life cycle. Darwin's concepts were continuous variation and "soft" heredity; Mendel espoused discontinuous variation and "hard" heredity. Thus, the combination of Mendelian genetics with Darwin's theory of natural selection was the process that resulted in the modern synthesis of evolutionary biology. Although biology, genetics, and genomics have been revolutionized in recent years, modern genetics will forever rely on simple principles founded on pea breeding using seven single gene characters. Purposeful use of mutants to study gene function is one of the essential tools of modern genetics. Today, over 100 plant species genomes have been sequenced. Mapping populations and their use in segregation of molecular markers and marker-trait association to map and isolate genes, were developed on the basis of Mendel's work. Genome-wide or genomic selection is a recent approach for the development of improved breeding lines. The analysis of complex traits has been enhanced by high-throughput phenotyping and developments in statistical and modeling methods for the analysis of phenotypic data. Introgression of novel alleles from landraces and wild relatives widens genetic diversity and improves traits; transgenic methodologies allow for the introduction of novel genes from diverse sources, and gene editing approaches offer possibilities to manipulate gene in a precise manner.
- MeSH
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- fenotyp MeSH
- genetická variace MeSH
- geneticky modifikované rostliny genetika MeSH
- genetika dějiny MeSH
- genom rostlinný MeSH
- genomika MeSH
- hrách setý genetika MeSH
- lokus kvantitativního znaku MeSH
- mapování chromozomů MeSH
- selekce (genetika) MeSH
- šlechtění rostlin * MeSH
- Check Tag
- dějiny 19. století MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- Publikační typ
- biografie MeSH
- časopisecké články MeSH
- historické články MeSH
- přehledy MeSH
- O autorovi
- Mendel, Johann Gregor, 1822-1884 Autorita
Spermatogenesis is a costly process that is expected to be under selection to maximise sperm quantity and quality. Testis size is often regarded as a proxy measure of sperm investment, implicitly overlooking the quantitative assessment of spermatogenesis. An enhanced understanding of testicular function, beyond testis size, may reveal further sexual traits involved in sperm quantity and quality. Here, we first estimated the inter-male variation in testicular function and sperm traits in red deer across the breeding and non-breeding seasons. Then, we analysed the relationships between the testis mass, eight parameters of spermatogenic function, and seven parameters of sperm quality. Our findings revealed that the Sertoli cell number and function parameters vary greatly between red deer males, and that spermatogenic activity co-varies with testis mass and sperm quality across the breeding and non-breeding seasons. For the first time in a seasonal breeder, we found that not only is the Sertoli cell number important in determining testis mass (r = 0.619, p = 0.007 and r = 0.248, p = 0.047 for the Sertoli cell number assessed by histology and cytology, respectively), but also sperm function (r = 0.703, p = 0.002 and r = 0.328, p = 0.012 for the Sertoli cell number assessed by histology and cytology, respectively). Testicular histology also revealed that a high Sertoli cell number per tubular cross-section is associated with high sperm production (r = 0.600, p = 0.009). Sperm production and function were also positively correlated (r = 0.384, p = 0.004), suggesting that these traits co-vary to maximise sperm fertilisation ability in red deer. In conclusion, our findings contribute to the understanding of the dynamics of spermatogenesis, and reveal new insights into the role of testicular function and the Sertoli cell number on testis size and sperm quality in red deer.
The objective of this paper was to adapt gene-flow methodology for the calculation of economic weights (EW) for direct and maternal traits and trait components in sheep and to apply this methodology to the Suffolk breed in the Czech Republic. Computer programs were developed in which annual-lambing sheep production systems with purebreeding or partial terminal crossing were simulated. Using these programs, the EW for 12 production and functional traits were estimated for i) Suffolk sires whose sons were used both in purebreeding and in terminal crossing with the 4 dual-purpose breeds, Romanov, Sumavska, Romney, and Merinolandschaf; and ii) Suffolk sires used only for terminal crossing. For case (i), the EW were at first calculated separately for the purebreeding system and for the crossing systems with the 4 dual-purpose breeds in dam position. Compound EW for the general breeding goal for Suffolk were then estimated as weighted averages from the EW in the 5 subsystems. Standardized EW were calculated by multiplying the marginal EW with the genetic SD of the trait, and relative EW were defined as absolute values of the standardized EW expressed as percentage of the sum of the absolute values of the standardized EW over all traits. The 5 most important trait components for Suffolk sires whose sons were used both in purebreeding and in terminal crossing were (relative EW given in parentheses): the direct components of survival rate until weaning (21.0%), daily BW gain until weaning (14.1%), survival rate at birth (14.0%), the maternal component of survival rate until weaning (10.7%), and litter size at lambing (7.6%). There were only small differences between the relative EW calculated for the whole system with pure- and crossbreeding and the relative EW for the purebred system within the Suffolk breed. Therefore, selection of Suffolk rams using a selection index based on the compound EW is expected to be of high efficiency in all of the simulated breeding systems. Only direct traits were relevant for Suffolk sires used only for terminal crossing; the most important (range of relative EW calculated for the 4 crossing systems given in parentheses) were survival rate until weaning (35.2 to 36.5%), daily BW gain until weaning (24.2 to 26.3%), and survival rate at birth (23.7 to 24.8%).
- MeSH
- biologické modely MeSH
- chov ekonomika MeSH
- genetická variace MeSH
- hmotnostní přírůstek MeSH
- ovce genetika MeSH
- rozmnožování genetika fyziologie MeSH
- tok genů MeSH
- vlna MeSH
- zemědělství ekonomika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
