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PubMed2000

Births of kittens produced by intracytoplasmic sperm injection of domestic cat oocytes matured in vitro.

In Experiment 1, cleavage frequency and in vitro development of domestic cat embryos produced after in vitro maturation of oocytes obtained from ovaries after ovariohysterectomy (in vitro) with that of oocytes retrieved from follicle-stimulating hormone-treated donors at 24 h after administration of luteinizing hormone (in vivo) and fertilization by intracytoplasmic sperm injection (ICSI) or IVF were compared. In each group presumptive zygotes were assessed for cleavage on IVC Days 1 and 4 and for development to blastocysts on IVC Day 7. In vitro matured oocytes had lower frequencies of meiotic maturation (59.2% v. 66.5%), cleavage at Day 1 (41.4% v. 64.9%) and development to the morula stage at Day 4 (65.8% v. 87.9%) than did in vivo matured oocytes, after ICSI and IVF. Development to the blastocyst stage was lower in in vitro matured oocytes (19.0%) than in vivo matured oocytes (29.5%) after ICSI. In Experiment 2, we evaluated the capacity of sperm injected oocytes without a visible polar body to undergo cleavage and in vitro development. More in vivo matured than in vitro matured oocytes underwent cleavage at Day 1 (46.6% v. 12.6%) and developed to the morula stage by Day 4 (66.7% v. 46.1%), but no blastocysts were obtained at Day 7 in either group. In Experiment 3, we evaluated the in vivo viability of domestic cat embryos derived from ICSI of in vitro matured oocytes. Morula stage embryos were transferred to 18 domestic cat recipients either on Day 4 or 5 after oocyte recovery. A total of 3 domestic cat recipients were pregnant after transfer to recipients on Day 5. Two pregnant cats delivered two normal and healthy live male kittens on Day 68 of gestation and the remaining cat delivered a male kitten on Day 62 that died during the last two days of gestation. These results demonstrate that: (1) inadequate cytoplasmic maturation of in vitro matured domestic cat oocytes is the main cause of deficient oocyte activation; (2) the injection of oocytes without a visible polar body is a useful technique to evaluate oocyte cytoplasmic maturation; and (3) blastocysts obtained after ICSI of in vitro matured oocytes are viable and not a result of parthenogenesis.

Animals↗

PubMed2005

Domestication of a Mesoamerican cultivated fruit tree, Spondias purpurea.

Contemporary patterns of genetic variation in crops reflect historical processes associated with domestication, such as the geographic origin(s) of cultivated populations. Although significant progress has been made in identifying several global centers of domestication, few studies have addressed the issue of multiple origins of cultivated plant populations from different geographic regions within a domestication center. This study investigates the domestication history of jocote (Spondias purpurea), a Mesoamerican cultivated fruit tree. Sequences of the chloroplast spacer trnG-trnS were obtained for cultivated and wild S. purpurea trees, two sympatric taxa (Spondias mombin var. mombin and Spondias radlkoferi), and two outgroups (S. mombin var. globosa and Spondias testudinus). A phylogeographic approach was used and statistically significant associations of clades and geographical location were tested with a nested clade analysis. The sequences confirm that wild populations of S. purpurea are the likely progenitors of cultivated jocote trees. This study provides phylogeographic evidence of multiple domestications of this Mesoamerican cultivated fruit tree. Haplotypes detected in S. purpurea trees form two clusters, each of which includes alleles recovered in both cultivated and wild populations from distinct geographic regions. Cultivated S. purpurea populations have fewer unique trnG-trnS alleles than wild populations; however, five haplotypes were absent in the wild. The presence of unique alleles in cultivation may reflect contemporary extinction of the tropical dry forests of Mesoamerica. These data indicate that some agricultural habitats may be functioning as reservoirs of genetic variation in S. purpurea.

Agriculture↗

PubMed2003

Domestication quantitative trait loci in Triticum dicoccoides, the progenitor of wheat.

Wild emmer wheat, Triticum dicoccoides, is the progenitor of modern tetraploid and hexaploid cultivated wheats. Our objective was to map domestication-related quantitative trait loci (QTL) in T. dicoccoides. The studied traits include brittle rachis, heading date, plant height, grain size, yield, and yield components. Our mapping population was derived from a cross between T. dicoccoides and Triticum durum. Approximately 70 domestication QTL effects were detected, nonrandomly distributed among and along chromosomes. Seven domestication syndrome factors were proposed, each affecting 5-11 traits. We showed: (i) clustering and strong effects of some QTLs; (ii) remarkable genomic association of strong domestication-related QTLs with gene-rich regions; and (iii) unexpected predominance of QTL effects in the A genome. The A genome of wheat may have played a more important role than the B genome during domestication evolution. The cryptic beneficial alleles at specific QTLs derived from T. dicoccoides may contribute to wheat and cereal improvement.

Alleles↗

PubMed1994

One subspecies of the red junglefowl (Gallus gallus gallus) suffices as the matriarchic ancestor of all domestic breeds.

The noncoding control region of the mitochondrial DNA of various gallinaceous birds was studied with regard to its restriction fragment length polymorphism (RFLP) and sequences of the first 400 bases. Tandem duplication of the 60-base unit was established as a trait unique to the genus Gallus, which is shared neither by pheasants nor by quails. Unlike its close ally Gallus varius (green junglefowl), the red junglefowl Gallus gallus is a genetically very diverse species; the 7.0% sequence divergence was seen between those from Thailand (G. g. gallus and G. g. spadiceus) and the other from the Indonesian island of Java (G. g. Bankiva). Furthermore, the divergence increased to 27.83% if each transversion is regarded as an equivalent of 10 transitions. On the other hand, a mere 0.5-3.0% difference (all transitions) separated various domestic breeds of the chicken from two G. g. gallus of Thailand, thus indicating a single domestication event in the area inhabited by this subspecies of the red junglefowl as the origin of all domestic breeds. Only transitions separated six diverse domesticated breeds. Nevertheless, a 2.75% difference was seen between RFLP type I breeds (White Leghorn and Nagoya) and a RFLP type VIII breed (Ayam Pelung). The above data suggested that although the mitochondrion of RFLP type V was the main contributor to domestication, hens of other RFLP types also contributed to this event.

Animals↗

PubMed1996

Monophyletic origin and unique dispersal patterns of domestic fowls.

With the aim of elucidating in greater detail the genealogical origin of the present domestic fowls of the world, we have determined mtDNA sequences of the D-loop regions for a total of 21 birds, of which 12 samples belong to red junglefowl (Gallus gallus) comprising three subspecies (six Gallus gallus gallus, three Gallus gallus spadiceus, and three Gallus gallus bankiva) and nine represent diverse domestic breeds (Gallus gallus domesticus). We also sequenced four green junglefowl (Gallus varius), two Lafayette's junglefowl (Gallus lafayettei), and one grey junglefowl (Gallus sonneratii). We then constructed a phylogenetic tree for these birds by the use of nucleotide sequences, choosing the Japanese quail (Coturnix coturnix japonica) as an outgroup. We found that a continental population of G. g. gallus was the real matriarchic origin of all the domestic poultries examined in this study. It is also of particular interest that there were no discernible differences among G. gallus subspecies; G. g. bankiva was a notable exception. This was because G. g. spadiceus and a continental population of G. g. gallus formed a single cluster in the phylogenetic tree. G. g. bankiva, on the other hand, was a distinct entity, thus deserving its subspecies status. It implies that a continental population of G. g. gallus sufficed as the monophyletic ancestor of all domestic breeds. We also discussed a possible significance of the initial dispersal pattern of the present domestic fowls, using the phylogenetic tree.

Animals↗

PubMed1998

Morphometrics of domestic Panstrongylus rufotuberculatus in Bolivia.

The trend to domesticity in Triatominae may represent a transitionary phase, towards increasing vectorial importance in the transmission of Chagas disease to humans, and requires sustained entomological surveillance. Although generally considered a sylvatic species, Panstrongylus rufotuberculatus has been recently captured inside human dwellings in the provinces of Nor Yungas and Muñecas in the Department of La Paz, Bolivia, providing evidence of this species' ability to colonise domestic habitats. The results of previous research on domestic and sylvatic specimens of other species of Triatominae indicate that morphometrics could be used to monitor this adaptive process. The most likely cause of differences seen in the size and shape of bugs from domestic colonies of P. rufotuberculatus from two neighbouring villages in Bolivia is probably genetic drift rather than environmental influences. Comparison with allopatric sylvatic specimens, including the holotype of P. rufatuberculatus, showed a general reduction in size from sylvatic to domestic specimens.

Animals↗

PubMed1999

Use of embryonic and somatic cells for production of transgenic domestic animals.

In contrast to the highly developed genetic modification systems available for manipulating the mouse genome, at this time only simple gain of function modifications can be undertaken in domestic species. Clearly, the greatest barrier to gene targeting in domestic species has been the unavailability of cell lines that can be modified in vitro and still be used to generate a living organism. In the mouse, the embryonic stem (ES) cells and embryonic germ (EG) cells have fulfilled that role. While the nuclear transfer procedures have solved this problem in sheep and cattle, in swine ES and EG cells are still needed. In addition, targeting in domestic species is affected by the need to develop targeting constructs containing isogenic DNA regions. As a result, it is necessary to isolate the gene of interest, sequence required regions, and develop isogenic targeting constructs by technologies such as long-range PCR. On the positive side, enrichment protocols developed in the mouse can be applied to domestic species, thus facilitating the identification of correctly modified cell lines. Hence, progress in mammalian cloning, the development of EG cell lines, and advances in gene targeting presently allows the introduction of precise genetic modifications into the domestic animal genome.

Journal Article↗

PubMed2001

Double exposure. The combined impact of domestic responsibilities and job strain on common symptoms in employed Swedish women.

BACKGROUND: This study investigated the influence of domestic responsibility and job strain, and especially simultaneous exposure to these factors (i.e. 'double exposure') on common physical and mental symptoms in Swedish women. METHODS: A questionnaire containing items on socio-economic factors, domestic responsibilities, and psychosocial working conditions was sent to a random population of women, 40 to 50 years of age, in a rural Swedish community. The response rate was 81.7% (397 women). Multiple logistic regression analyses were used to test for potential confounding factors and effect modification. Attributable risks were computed based on prevalence data. RESULTS: Women shouldering great domestic responsibility or who experienced job strain were at risk of a high level of common symptoms (OR 1.76; 1.04-2.97 and OR 3.48; 2.05-5.92, respectively). 'Double exposure' considerably increased the odds for common symptoms (OR 6.91; 2.58-18.48), with support for synergy noted. The population attributable risk (PAR) of great domestic responsibility was 10.0% and of job strain it was 26.7% in producing a high level of common symptoms. The corresponding figure for the population of women subjected to 'double exposure' was 11.8% and for the population of women subjected to either single or 'double exposure' the PAR was 30.3%. CONCLUSION: Heavy domestic responsibility and/or a job strain situation are factors that seem to make important contributions to the causes of a high level of common symptoms among salaried women 40 to 50 years of age. 'Double exposure' showed a particularly high risk because of synergy.

Adult↗

PubMed2002

Comparative sequencing in the genus Lycopersicon. Implications for the evolution of fruit size in the domestication of cultivated tomatoes.

Sequence variation was sampled in cultivated and related wild forms of tomato at fw2.2--a fruit weight QTL key to the evolution of domesticated tomatoes. Variation at fw2.2 was contrasted with variation at four other loci not involved in fruit weight determination. Several conclusions could be reached: (1) Fruit weight variation attributable to fw2.2 is not caused by variation in the FW2.2 protein sequence; more likely, it is due to transcriptional variation associated with one or more of eight nucleotide changes unique to the promoter of large-fruit alleles; (2) fw2.2 and loci not involved in fruit weight have not evolved at distinguishably different rates in cultivated and wild tomatoes, despite the fact that fw2.2 was likely a target of selection during domestication; (3) molecular-clock-based estimates suggest that the large-fruit allele of fw2.2, now fixed in most cultivated tomatoes, arose in tomato germplasm long before domestication; (4) extant accessions of L. esculentum var. cerasiforme, the subspecies thought to be the most likely wild ancestor of domesticated tomatoes, appear to be an admixture of wild and cultivated tomatoes rather than a transitional step from wild to domesticated tomatoes; and (5) despite the fact that cerasiforme accessions are polymorphic for large- and small-fruit alleles at fw2.2, no significant association was detected between fruit size and fw2.2 genotypes in the subspecies--as tested by association genetic studies in the relatively small sample studied--suggesting the role of other fruit weight QTL in fruit weight variation in cerasiforme.

Alleles↗

PubMed2004

Selection versus demography: a multilocus investigation of the domestication process in maize.

The domestication of maize (Zea mays ssp. mays) from its wild ancestor (Zea mays ssp. parviglumis) led to a loss of genetic diversity both through a population bottleneck and through directional selection at agronomically important genes. In order to discriminate between those effects and to investigate the nature of the domestication bottleneck, we analyzed nucleotide diversity data from 12 chromosome 1 loci in parviglumis. We found an average loss of nucleotide diversity of 38% across genes, but this average was skewed downward by four putatively selected loci (tb1, d8, ts2, and zagl1). To better understand the domestication process, we used the coalescent with recombination to simulate bottlenecks under various lengths and population sizes. For each locus, we determine the likelihood of the observed data using three summary statistics: the number of segregating sites, an estimate of the population recombination parameter, and Tajima's D. Based on the eight neutrally evolving loci, a model with a bottleneck had a significantly higher likelihood than a model without one. The four putatively selected loci had significantly different likelihood optimums than the neutral loci, and this approach confirmed that ts2 and d8 were selected either during domestication or breeding. Overall, the best-fitting models had a bottleneck in which the population size and the bottleneck duration had a ratio of approximately 4- to approximately 5; for example, if the initial domestication event occurred over a 500-year period, the population size was roughly 2,000 to 2,500 individuals. However, this range did vary with the summary statistic used to assess the fit of simulations to data. In this context, Tajima's D performed poorly as a goodness-of-fit statistic, probably because Z. mays ssp. parviglumis has a frequency spectrum that is significantly skewed toward low-frequency variants. Finally, we found that demography is unlikely to account for the previously observed positive correlation between nucleotide diversity and the population-recombination parameter in maize, leaving this observation difficult to interpret.

Amino Acid Sequence↗

PubMed2005

Estimating a nucleotide substitution rate for maize from polymorphism at a major domestication locus.

To estimate a rate for single nucleotide substitutions for maize (Zea mays ssp. mays), we have taken advantage of data from genetic and archaeological studies of the domestication of maize from its wild ancestor, teosinte (Z. mays ssp. parviglumis). Genetic studies have shown that the teosinte branched1 (tb1) gene was a major target of human selection during maize domestication, and sequence diversity in the intergenic region 5' to the tb1-coding sequence is extraordinarily low. We show that polymorphism in this region is consistent with new mutation following fixation for a small number of tb1 haplotypes during domestication. Archeological studies suggest that maize was domesticated approximately 6,250-10,000 years ago and subsequently the size of the maize population is thought to have expanded rapidly. Using the observed number of mutations within the region of selection at tb1, the approximate age of maize domestication, and approximations for the maize genealogy, we have derived estimates for the nucleotide substitution rate for the tb1 intergenic region. Using two approaches, one of which is a coalescent approach, we obtain rate estimates of approximately 2.9 x 10(-8) and 3.3 x 10(-8) substitutions per site per year. We also show that the pattern of polymorphism in the tb1 intergenic region appears to have been strongly affected by the mutagenic effect of DNA methylation. Excluding target sites of symmetric DNA methylation (CG and CNG sites) from analysis, the mutation rate estimates are reduced by approximately 50%-60%, while the rates for CG and CNG sites are nearly an order of magnitude higher. We use rate estimates from the tb1 region to estimate the timing of expansion of transposable elements in the maize genome and suggest that this expansion occurred primarily within the last million years.

Base Sequence↗

PubMed2000

On the origin and domestication history of Barley (Hordeum vulgare).

Remains of barley (Hordeum vulgare) grains found at archaeological sites in the Fertile Crescent indicate that about 10,000 years ago the crop was domesticated there from its wild relative Hordeum spontaneum. The domestication history of barley is revisited based on the assumptions that DNA markers effectively measure genetic distances and that wild populations are genetically different and they have not undergone significant change since domestication. The monophyletic nature of barley domestication is demonstrated based on allelic frequencies at 400 AFLP polymorphic loci studied in 317 wild and 57 cultivated lines. The wild populations from Israel-Jordan are molecularly more similar than are any others to the cultivated gene pool. The results provided support for the hypothesis that the Israel-Jordan area is the region in which barley was brought into culture. Moreover, the diagnostic allele I of the homeobox gene BKn-3, rarely but almost exclusively found in Israel H. spontaneum, is pervasive in western landraces and modern cultivated varieties. In landraces from the Himalayas and India, the BKn-3 allele IIIa prevails, indicating that an allelic substitution has taken place during the migration of barley from the Near East to South Asia. Thus, the Himalayas can be considered a region of domesticated barley diversification.

Base Sequence↗

PubMed2005

Conservation genomics: disequilibrium mapping of domestic cattle chromosomal segments in North American bison populations.

Introgressive hybridization is one of the major threats to species conservation, and is often induced by human influence on the natural habitat of wildlife species. The ability to accurately identify introgression is critical to understanding its importance in evolution and effective conservation management of species. Hybridization between North American bison (Bison bison) and domestic cattle (Bos taurus) as a result of human activities has been recorded for over 100 years, and domestic cattle mitochondrial DNA was previously detected in bison populations. In this study, linked microsatellite markers were used to identify domestic cattle chromosomal segments in 14 genomic regions from 14 bison populations. Cattle nuclear introgression was identified in five populations, with an average frequency per population ranging from 0.56% to 1.80%. This study represents the first use of linked molecular markers to examine introgression between mammalian species and the first demonstration of domestic cattle nuclear introgression in bison. To date, six public bison populations have been identified with no evidence of mitochondrial or nuclear domestic cattle introgression, providing information critical to the future management of bison genetic resources. The ability to identify even low levels of introgression resulting from historic hybridization events suggests that the use of linked molecular markers to identify introgression is a significant development in the study of introgressive hybridization across a broad range of taxa.

Animals↗

PubMed2006

Bayesian analyses of admixture in wild and domestic cats (Felis silvestris) using linked microsatellite loci.

Methods recently developed to infer population structure and admixture mostly use individual genotypes described by unlinked neutral markers. However, Hardy-Weinberg and linkage disequilibria among independent markers decline rapidly with admixture time, and the admixture signals could be lost in a few generations. In this study, we aimed to describe genetic admixture in 182 European wild and domestic cats (Felis silvestris), which hybridize sporadically in Italy and extensively in Hungary. Cats were genotyped at 27 microsatellites, including 21 linked loci mapping on five distinct feline linkage groups. Genotypes were analysed with structure 2.1, a Bayesian procedure designed to model admixture linkage disequilibrium, which promises to assess efficiently older admixture events using tightly linked markers. Results showed that domestic and wild cats sampled in Italy were split into two distinct clusters with average proportions of membership Q > 0.90, congruent with prior morphological identifications. In contrast, free-living cats sampled in Hungary were assigned partly to the domestic and the wild cat clusters, with Q < 0.50. Admixture analyses of individual genotypes identified, respectively, 5/61 (8%), and 16-20/65 (25-31%) hybrids among the Italian wildcats and Hungarian free-living cats. Similar results were obtained in the past using unlinked loci, although the new linked markers identified additional admixed wildcats in Italy. Linkage analyses confirm that hybridization is limited in Italian, but widespread in Hungarian wildcats, a population that is threatened by cross-breeding with free-ranging domestic cats. The total panel of 27 loci performed better than the linked loci alone in the identification of domestic and known hybrid cats, suggesting that a large number of linked plus unlinked markers can improve the results of admixture analyses. Inferred recombination events led to identify the population of origin of chromosomal segments, suggesting that admixture mapping experiments can be designed also in wild populations.

Animals↗

PubMed2006

Domestication and the distribution of genetic variation in wild and cultivated populations of the Mesoamerican fruit tree Spondias purpurea L. (Anacardiaceae).

Domestication occurs as humans select and cultivate wild plants in agricultural habitats. The amount and structure of variation in contemporary cultivated populations has been shaped, in part, by how genetic material was transferred from one cultivated generation to the next. In some cultivated tree species, domestication involved a shift from sexually reproducing wild populations to vegetatively propagated cultivated populations; however, little is known about how domestication has impacted variation in these species. We employed AFLP data to explore the amount, structure, and distribution of variation in clonally propagated domesticated populations and sexually reproducing wild populations of the Neotropical fruit tree, Spondias purpurea (Anacardiaceae). Cultivated populations from three different agricultural habitats were included: living fences, backyards, and orchards. AFLP data were analysed using measures of genetic diversity (% polymorphic loci, Shannon's diversity index, Nei's gene diversity, panmictic heterozygosity), population structure (F(ST) analogues), and principal components analyses. Levels of genetic variation in cultivated S. purpurea populations are significantly less than variation found in wild populations, although the amount of diversity varies in different agricultural habitats. Cultivated populations have a greater proportion of their genetic variability distributed among populations than wild populations. The genetic structure of backyard populations resembles that of wild populations, but living fence and orchard populations have 1/3 more variability distributed among populations, most likely a reflection of relative levels of vegetative reproduction. Finally, these results suggest that S. purpurea was domesticated in two distinct regions within Mesoamerica.

Anacardiaceae↗

PubMed2006

Genetic analysis of rice domestication syndrome with the wild annual species, Oryza nivara.

With a small and sequenced genome, rice provides an excellent system for studying the genetics of cereal domestication. We conducted a quantitative trait locus (QTL) analysis of key domestication traits using an F2 population derived from a cross between the cultivated rice, Oryza sativa, and the annual wild species, O. nivara. We found that the QTL of large phenotypic effects were targeted by domestication selection for effective harvest and planting, including a reduction in seed shattering and seed dormancy and the synchronization of seed maturation. Selection for higher yield was probably responsible for the fixation of mutations at a cluster of QTL on chromosome 7 and a few other chromosomal locations that could have substantially improved plant architecture and panicle structure, resulting in fewer erect tillers and longer and more highly branched panicles in cultivated rice. In comparison with the wild perennial species, O. rufipogon, rice domestication from O. nivara would have involved QTL with a greater degree of chromosomal co-localization and required little genetic change associated with life history or mating system transitions. The genetic analyses of domestication traits with both wild relatives will open opportunities for the improvement of rice cultivars utilizing natural germplasm.

Chromosome Mapping↗

PubMedDate not supplied

Ciliated protozoa in the rumen of Turkish domestic cattle (Bos taurus L.).

Rumen contents obtained from 28 domesticated cattle (Bos taurus L.) slaughtered at abatoirs near Izmir, Turkey were surveyed for ciliate protozoa. Protozoa are known to make an appreciable contribution to ruminal fiber digestion in many different geographical areas; however, little if any information is available on their occurrence in Turkish cattle. As a result of our survey, 13 genera including 52 species were identified. Nine of the species were further divided into 36 forma. The average ciliate density in our cattle (52.44 X 10(4)/ml) was higher than that of Turkish domestic sheep and other domestic cattle reported previously from different geographical areas. Entodinium basoglui, Entodinium williamsi f. williamsi, E. williamsi f. turcicum, E. dalli f. rudidorsospinatum, Entodinium imai, Entodinium oektemae, Eudiplodinium dehorityi, Epidinium graini, Ophryoscolex purkynjei f. bifidobicinctus, and Ophryoscolex purkynjei f. bifidoquadricinctus have previously been reported from Turkey and appear to be endemic. All ofthe remaining species represent a new host record for domestic Turkish cattle. This study also reports for the second time the presence of Entodinium constrictum in herbivorous mammals, and is the first record of its occurrence in domesticated cattle.

Animals↗

PubMed1984

Domestic smoke pollution and chronic bronchitis in a rural community of the Hill Region of Nepal.

An earlier study of chronic bronchitis in a rural community of the Hill Region of Nepal using Medical Research Council criteria showed a high prevalence rate that was more or less equal in the two sexes. Most of the women in the study population are exposed to domestic smoke caused by wood and straw fires used for cooking and heating purposes in the ill ventilated houses without chimneys. Data from 1375 individuals were analysed to determine whether there was any relationship between domestic smoke pollution and chronic bronchitis. Exposure to domestic smoke was assessed according to the average time per day spent near the fireplace. The association between chronic bronchitis and cigarette smoking was confirmed. In female nonsmokers and smokers and past smokers of both sexes crude and age adjusted prevalence rates for chronic bronchitis were significantly associated with increasing exposure to domestic smoke. In the living conditions existing in the rural Hill Region of Nepal domestic smoke pollution is an important contributing factor in the development of chronic bronchitis.

Adult↗