Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 183
Filter
1.
Fertil Steril ; 121(1): 4-11, 2024 01.
Article in English | MEDLINE | ID: mdl-37993053

ABSTRACT

The oocyte, a long-lived, postmitotic cell, is the locus of reproductive aging in women. Female germ cells replicate only during fetal life and age throughout reproductive life. Mechanisms of oocyte aging include the accumulation of oxidative damage, mitochondrial dysfunction, and disruption of proteins, including cohesion. Nobel Laureate Bob Edwards also discovered a "production line" during oogonial replication in the mouse, wherein the last oocytes to ovulate in the adult-derived from the last oogonia to exit mitotic replication in the fetus. On the basis of this, we proposed a two-hit "telomere theory of reproductive aging" to integrate the myriad features of oocyte aging. The first hit was that oocytes remaining in older women traversed more cell cycles during fetal oogenesis. The second hit was that oocytes accumulated more environmental and endogenous oxidative damage throughout the life of the woman. Telomeres (Ts) could mediate both of these aspects of oocyte aging. Telomeres provide a "mitotic clock," with T attrition an inevitable consequence of cell division because of the end replication problem. Telomere's guanine-rich sequence renders them especially sensitive to oxidative damage, even in postmitotic cells. Telomerase, the reverse transcriptase that restores Ts, is better at maintaining than elongating T. Moreover, telomerase remains inactive during much of oogenesis and early development. Oocytes are left with short Ts, on the brink of viability. In support of this theory, mice with induced T attrition and women with naturally occurring telomeropathy suffer diminished ovarian reserve, abnormal embryo development, and infertility. In contrast, sperm are produced throughout the life of the male by a telomerase-active progenitor, spermatogonia, resulting in the longest Ts in the body. In mice, cleavage-stage embryos elongate Ts via "alternative lengthening of telomeres," a recombination-based mechanism rarely encountered outside of telomerase-deficient cancers. Many questions about Ts and reproduction are raised by these findings: does the "normal" T attrition observed in human oocytes contribute to their extraordinarily high rate of meiotic nondisjunction? Does recombination-based T elongation render embryos susceptible to mitotic nondisjunction (and mosaicism)? Can some features of Ts serve as markers of oocyte quality?


Subject(s)
Telomerase , Male , Female , Humans , Mice , Animals , Aged , Telomerase/genetics , Telomerase/metabolism , Semen/metabolism , Reproduction/genetics , Aging/genetics , Oocytes/metabolism , Telomere/genetics
2.
Animal ; 18(1): 101048, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38160592

ABSTRACT

Beyond providing food, livestock species are linked to a wide range of uses and ecosystem services (ESs). Based on information reported by 41 countries on 3 361 national breed populations to the Domestic Animal Diversity Information System of the Food and Agriculture Organization of the United Nations, we investigated how factors such as species, region, breed adaptedness, or management system associate with the recognition of provision of a set of 52 ESs. Among species, a greater number of cultural ESs were reported for horses (2.47 for horses vs 0.75 on average across all species), while the major ruminant species (cattle, goats and sheep) were on average associated with more provisioning ESs (2.99 vs 2.39), and more regulating and maintenance ESs (1.86 vs 1.32). Compared to European breeds, African livestock contribute more provisioning ES (3.95 vs 1.88). Native breeds and, to a lesser extent, locally adapted breeds, were linked to more ESs than were exotic breeds (5.97 and 4.10 vs 2.90, respectively), regardless of the ES category considered. The total number of ES reported was greater for breeds primarily kept under Back Yard/Farm Yard and extensive management systems than in other production environments. Different "bundles" of ES were identified in relation to the interdependence among themselves, or according to species or regional specificities. Overall, our results highlight that native and locally adapted breeds, which tend to be raised in less specialized production systems than exotic breeds, are reported to play multiple roles contributing to rural community livelihoods and environmental sustainability of food systems.


Subject(s)
Ecosystem , Livestock , Animals , Cattle , Sheep , Horses , Conservation of Natural Resources/methods , Animals, Domestic , Agriculture , Goats
3.
RSC Adv ; 13(9): 6287-6303, 2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36825284

ABSTRACT

The development of photoactive systems to solve serious environmental problems is a key objective of researchers and remains a real challenge. Herein, n-p heterojunction ZnO-based composites were developed to achieve better photocatalytic performance in methylene blue (MB) degradation under natural solar irradiation. The hydrothermal technique was used to synthesize zinc oxide (ZnO)/metal oxide (MO) composites, with a molar ratio of 1 : 1 (MO = Mn3O4; Fe3O4; CuO; NiO). Various characterization techniques were used for the analysis of the structural, morphological and optical properties. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) Diffuse Reflectance Spectroscopy analysis (DRS), and Diffuse Reflectance Spectroscopy analysis (DRS) validated the presence of two phases for each sample, excluding any impurities. Indeed, the ZnO structure was not affected by the coupling with MO, confirming that MO was well dispersed on the surface of the ZnO crystalline lattice for each composite. Eventually, the photocatalytic performance evaluation test of the synthesized photocatalysts was carried out on aqueous MB solution. According to the results, the ZnO/Fe3O4 nano-catalyst showed the best photodegradation efficiency. This result suggests that the formation of Fe3O4/ZnO as a p/n heterojunction reduces the recombination of photo-generated electron/hole pairs and broadens the solar spectral response range, resulting in significant photocatalytic efficiency. Meanwhile, the possible mechanism for degradation of the MB was discussed.

4.
Am J Obstet Gynecol ; 226(3): 379-383, 2022 03.
Article in English | MEDLINE | ID: mdl-34111406

ABSTRACT

In the past, the reproductive freedom of African American women was hindered by forced reproduction and sterilization campaigns. Unfortunately, these involuntary practices have now mostly been replaced by inequality because of disproportionate tubal factor infertility rates within African American communities. Our work aimed to describe the inequities in increased rates of pelvic inflammatory disease and tubal factor infertility as it relates to African American women. In addition, we highlighted the need for improved access to screening and treatment of sexually transmitted infections, access to barrier contraception, and health literacy related to the understanding and prevention of tubal factor infertility in African American women.


Subject(s)
Infertility, Female , Infertility , Pelvic Inflammatory Disease , Black or African American , Female , Freedom , Humans , Infertility/complications , Infertility, Female/etiology , Pelvic Inflammatory Disease/diagnosis , Reproduction
6.
J Assist Reprod Genet ; 38(9): 2283-2289, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34125361

ABSTRACT

PURPOSE: Whether differences in stimulation parameters alter the number and proportion of MII oocytes retrieved. METHODS: Records of 2546 patients were examined, looking at age, day 2/3 follicle-stimulating hormone (FSH) and estradiol (E2) levels, total dose of gonadotropins administered (including FSH and human menopausal gonadotropin [hMG]), fraction of hMG administered, number of days of treatment with gonadotropins, and the dose of gonadotropins administered per day. We segregated the patients into 3 different classes depending on the trigger method used and 2 groups based on egg freeze vs. ICSI. Multiple regression methods were used to examine associations between stimulation parameters and the total number of eggs, number of immature oocytes (Poisson regression), and the fraction of retrieved oocytes that were immature (Logistic regression). RESULTS: After adjustments for different triggers and egg freeze versus ICSI, both the #immature oocytes and the immature fraction of oocytes were associated with the total gonadotropin dose (inversely) and the gonadotropin dose/day (positively). Other parameters were associated with the number of immature oocytes but were also associated with the number of oocytes retrieved. CONCLUSIONS: Stimulations using less total gonadotropin and more gonadotropin per day were associated with more immaturity. The type of trigger method used for final maturation was associated with immaturity but was believed to be predominantly due to trigger assignment to patients based on response. The association between use of ICSI and less immaturity was believed to be due to additional time for maturation in the ICSI group.


Subject(s)
Chorionic Gonadotropin/administration & dosage , Fertilization in Vitro/methods , Oocyte Retrieval/methods , Oocytes/cytology , Oogenesis , Ovulation Induction/methods , Adolescent , Adult , Child , Female , Fertility Agents, Female/administration & dosage , Follicle Stimulating Hormone/metabolism , Gonadotropin-Releasing Hormone/metabolism , Humans , Middle Aged , Oocytes/drug effects , Oocytes/metabolism , Pregnancy , Pregnancy Rate , Reproductive Techniques, Assisted , Retrospective Studies , Young Adult
7.
J Assist Reprod Genet ; 37(5): 1221-1225, 2020 May.
Article in English | MEDLINE | ID: mdl-32405899

ABSTRACT

PURPOSE: To determine the impact of accelerated telomere shortening on the fertility parameters and treatment outcomes of a woman with dyskeratosis congenita (DKC). METHODS: A case study of the clinical data, blood, discarded oocytes, and arrested embryos of a woman with DKC and donated cryopreserved embryos from unaffected patients. Mean telomere length in blood cells was analyzed by flow cytometry-fluorescence in situ hybridization (flow-FISH) and qPCR. The load of short telomeres in blood cells was measured by universal single telomere length analysis (Universal STELA). The mean telomere length in embryos was analyzed by single-cell amplification of telomere repeats (SCATR) PCR. RESULTS: Comparison of clinical parameters revealed that the DKC patient had reduced anti-Mullerian hormone (0.3 vs 4.1 ± 5.7 ng/ML), reduced oocytes retrieved (7 vs 18.5 ± 9.5), reduced fertilization rate, and reduced euploidy rate relative to unaffected patients. Additionally, mean telomere length in DKC embryos were shorter than unaffected embryos. However, hormone treatment led to increased leukocyte telomere length, while the load of short telomeres was also shown to decrease during the course of treatment. CONCLUSIONS: We demonstrate for the first time the direct detrimental impacts of short telomeres on female fertility. We further demonstrate positive effects of hormone treatments for people with telomere disorders.


Subject(s)
Dyskeratosis Congenita/genetics , Fertility Preservation , Oocytes/ultrastructure , Telomere Shortening/genetics , Dyskeratosis Congenita/diagnosis , Dyskeratosis Congenita/physiopathology , Female , Flow Cytometry , Humans , In Situ Hybridization, Fluorescence , Oocytes/pathology , Telomerase/genetics , Telomere/genetics , Telomere/ultrastructure , Telomere Homeostasis/genetics
8.
Animal ; 14(4): 670-680, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31685075

ABSTRACT

Conservation of animal genetic resources requires regular monitoring and interventions to maintain population size and manage genetic variability. This study uses genealogical information to evaluate the impact of conservation measures in Europe, using (i) data from the Domestic Animal Diversity Information System (DAD-IS) and (ii) a posteriori assessment of the impact of various conservation measures on the genetic variability of 17 at-risk breeds with a wide range of interventions. Analysis of data from DAD-IS showed that 68% of national breed populations reported to receive financial support showed increasing demographic trends, v. 51% for those that did not. The majority of the 17 at-risk breeds have increased their numbers of registered animals over the last 20 years, but the changes in genetic variability per breed have not always matched the trend in population size. These differences in trends observed in the different metrics might be explained by the tensions between interventions to maintain genetic variability, and development initiatives which lead to intensification of selection.


Subject(s)
Cattle/genetics , Conservation of Natural Resources , Equidae/genetics , Genetic Variation , Livestock/genetics , Ruminants/genetics , Animals , Animals, Domestic , Breeding , Demography , Europe , Female , Male , Pedigree , Population Density
9.
J Assist Reprod Genet ; 36(9): 1877-1890, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31332596

ABSTRACT

PURPOSE: To identify and characterize amyloid-like substance (ALS) in human and mouse oocytes and preimplantation embryos. METHODS: An experimental prospective pilot study. A total of 252 mouse oocytes and preimplantation embryos and 50 immature and in vitro matured human oocytes and parthenogenetic human embryos, from 11 consenting fertility patients, ages 18-45. Fluorescence intensity from immunofluorescent staining and data from confocal microscopy were quantified. Data were compared by one-way analysis of variance, with the least square-MEANS post-test, Pearson correlation coefficients (r), and bivariate analyses (t tests). ALS morphology was verified using transmission electron microscopy. RESULTS: Immunostaining for ALS appears throughout the zona pellucida, as well as in the cytoplasm and nucleus of mouse and human oocytes, polar bodies, and parthenogenetic embryos, and mouse preimplantation embryos. In mouse, 2-cell embryos exhibited the highest level of ALS (69000187.4 ± 6733098.07). Electron microscopy confirmed the presence of ALS. In humans, fresh germinal vesicle stage oocytes exhibited the highest level of ALS (4164.74088 ± 1573.46) followed by metaphase I and II stages (p = 0.008). There was a significant negative association between levels of ALS and patient body mass index, number of days of ovarian stimulation, dose of gonadotropin used, time between retrieval and fixation, and time after the hCG trigger. Significantly higher levels of ALS were found in patients with AMH between 1 and 3 ng/ml compared to < 1 ng/ml. CONCLUSION: We demonstrate for the first time the presence, distribution, and change in ALS throughout some stages of mouse and human oocyte maturation and embryonic development. We also determine associations between ALS in human oocytes with clinical characteristics.


Subject(s)
Amyloid/metabolism , Blastocyst/metabolism , Oocytes/metabolism , Adolescent , Adult , Animals , Body Mass Index , Female , Humans , In Vitro Oocyte Maturation Techniques , Metaphase , Mice , Microscopy, Fluorescence , Middle Aged , Oocyte Retrieval , Ovulation Induction , Parthenogenesis , Pilot Projects , Prospective Studies , Young Adult , Zona Pellucida/metabolism
10.
Heliyon ; 5(6): e01912, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31245643

ABSTRACT

This work is focused on the photocatalytic activities of undoped ZnO, Co (1%) doped ZnO (CZO) and In (1%) doped ZnO (IZO) thin films grown on flexible PEI (Polyetherimide) substrate by spray pyrolysis. The photodegradation of crystal violet dye was investigated under UV and sunlight irradiations. Doping and excitation energy effects on photocatalytic efficiencies are discussed. All ZnO thin films show high photocatalytic efficiency up to 80% under either UV or sunlight irradiations for 210 min. However, CZO has the higher photocatalytic performance under UV irradiation. While, the photodegradation efficiency of IZO was enhanced under sunlight irradiation due to the narrowing of its optical gap. These results are discussed based on structural, morphological and optical investigations. The photocatalytic stability of ZnO films was studied as well. So, after three photocatalysis cycles, all ZnO thin films still effective. The obtained results are promising for the use of doped ZnO/PEI as talented photocatalysts for applications in large surfaces with various geometries for photodegradation of hazardous pollutants.

11.
Vet J ; 248: 18-24, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31113557

ABSTRACT

Breeding against canine hip dysplasia (HD) may benefit from the importation of foreign sires. When foreign sires are evaluated on a different HD scale, this may diminish the efficacy. Using stochastic simulations, we evaluated genetic change and inbreeding levels for different scenarios of importing sires with high genetic merit for HD. Population size and genetic parameters (e.g. heritability, accuracy of selection, genetic correlation) were based on actual data for HD in Golden retrievers and Labrador retrievers in the UK and Sweden. For countries with different HD scales and an estimated breeding value (EBV) evaluation in place, the importation was useful if imported sires had EBV rankings in the top 50% and if genetic correlations between EBV systems were above 0.85. When importing sires with EBV rankings in the top 10%, moderate accuracies of EBVs (>0.40) and moderately strong genetic correlations (>0.70) were needed. Selection against HD without the importation of sires may increase inbreeding levels, while the importation of sires can decrease inbreeding levels. For national genetic evaluation and selection programmes, importing sires with high genetic merit can be an effective breeding strategy, but care is needed to estimate reliable EBVs.


Subject(s)
Breeding , Hip Dysplasia, Canine/prevention & control , Animals , Dogs , Europe , Female , Genetic Predisposition to Disease , Hip Dysplasia, Canine/genetics , Male , Pedigree , Pregnancy , Selection, Genetic , Stochastic Processes
12.
Int J Radiat Oncol Biol Phys ; 103(1): 112-115, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30099132

ABSTRACT

PURPOSE: Prostate cancer survivors who receive androgen deprivation therapy (ADT) are at increased risk of cardiovascular disease. They require coordinated care between cancer specialists and primary care physicians to monitor for cancer control and manage cardiovascular risk factors. METHODS AND MATERIALS: We prospectively enrolled 103 men receiving ADT with radiation therapy (RT) from 7 institutions to assess cardiovascular risk factors and survivorship care. Medical records, fasting laboratory test values, and patient-reported outcomes using a validated instrument were assessed at baseline (pretreatment) and 1 year post-RT. RESULTS: Cardiovascular disease (39%) and risk factors (diabetes, 22%; hypertension, 63%; hyperlipidemia, 31%) were prevalent at baseline. During the first year after RT completion, 63% received cardiovascular monitoring concordant with American Heart Association guidelines. Fasting laboratory test values at 1 year showed 24% with inadequately controlled blood sugar and 22% elevated cholesterol. Patient perceptions about care coordination were relatively low. At 1 year, 57% reported that their primary care physicians "always know about the care I receive at other places," 67% reported that their cancer physician "communicated with other providers I see," and 65% reported that the cancer care physician "knows the results of my visits with other doctors." CONCLUSIONS: Patients with prostate cancer who receive ADT and RT are a vulnerable population with prevalent baseline cardiovascular disease and risk factors and suboptimal survivorship care specifically related to coordinated care and cardiovascular monitoring. Clinical trials examining ways to improve the care and outcomes of these survivors are needed.


Subject(s)
Androgen Antagonists/adverse effects , Cancer Survivors , Cardiovascular Diseases/prevention & control , Preventive Medicine , Prostatic Neoplasms/mortality , Prostatic Neoplasms/therapy , Aged , Aged, 80 and over , Cardiovascular Diseases/etiology , Humans , Male , Middle Aged , Prospective Studies , Prostatic Neoplasms/complications
13.
Animal ; 12(12): 2627-2638, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29757124

ABSTRACT

This study investigates how the ecosystem services (ES) linked to livestock grazing are perceived across countries. A total of 82 case studies collected from 42 countries via survey (53.7% cases from Europe and 46.3% from outside of Europe) have been analysed through a multivariate approach. In all, 18 non-provisioning ES were considered. Overall, the reported impacts of livestock grazing on the different ES were much more positive than negative. Notably, a large proportion of respondents reported either positive or very positive impacts for some cultural ES, namely cultural, historic and natural heritage (84%), knowledge systems and educational values (77%), landscape values (74%), and for some supporting and regulating ES, namely habitat provision (66%), nutrient cycling (65%), and bush encroachment/fire control (66%). Based on multiple regression analysis, geographic origin, stakeholder type and species category, as well as protection status of the grazing area, had significant effects on the perception of the impacts. Respondents reported those impacts as more positive in Europe, in protected areas and where several species were present in the grazing area. A significantly larger proportion of respondents reported recognition of ES provided by the grazing livestock population in European countries (40.9%) compared with non-European countries (23.7%). Based on the survey responses it appears that in non-European countries absence of formal recognition, especially by policy makers, is a major challenge for the continued provision of ES in grazing systems. In Europe, where such recognition is already often included in legislation, the long-term sustainability of related policies and incentives to provide such services is viewed as a major issue by the respondents.


Subject(s)
Conservation of Natural Resources , Ecosystem , Livestock , Animals , Europe , Plants
14.
Vet J ; 234: 130-135, 2018 04.
Article in English | MEDLINE | ID: mdl-29680385

ABSTRACT

To improve the health and welfare of pedigree dogs, national kennel clubs (KCs) are key players in the governance and regulation of dog breeding. In a survey conducted to investigate differences between KCs in breeding policies and management of pedigree dogs, a questionnaire was completed by 15 KCs from 11 European countries (Austria, Belgium, Denmark, France, Germany, Ireland, Latvia, The Netherlands, Norway, Sweden and the United Kingdom) and four non-European countries (Australia, Mexico, Uruguay and the USA). The most important concerns reported by KCs were exaggerated morphological features and inherited disorders. A wide variety of information, tools and strategies was used to address these issues, with implementation differing across countries and breeds. KCs reported progress in the collection and provision of information related to canine health and welfare. Implementation of advanced breeding tools, such as genetic evaluation and online advisory mating tools, and balanced breeding strategies, endorsed by clubs and breeders, remain challenging and require further development.


Subject(s)
Breeding/legislation & jurisprudence , Dog Diseases/genetics , Dog Diseases/prevention & control , Pedigree , Animal Welfare , Animals , Dogs , Female , Male
15.
Vet J ; 226: 51-56, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28911842

ABSTRACT

In order to reduce the prevalence of inherited diseases in pedigree dogs, the feasibility of implementation of an international breeding program was investigated. One prerequisite is a strong genetic correlation between countries and our objective was to estimate this correlation for canine hip dysplasia (HD) across three countries to evaluate the feasibility of an international genetic evaluation. Data were provided by the Société Centrale Canine (SCC, France), Svenska Kennelklubben (SKK, Sweden) and The Kennel Club (KC, UK) on Golden retriever and Labrador retriever dogs. Trivariate analysis on the three different modes of scoring HD in France, Sweden and the UK was performed using a mixed linear animal model. Heritability, genetic correlation, number of common sires, genetic similarity, selection differentials and accuracy of selection were calculated. The estimated heritabilities of Golden retrievers (Labrador retrievers) for HD scores were 0.28 (0.15), 0.28 (0.29) and 0.41 (0.34) in France, Sweden and the UK, respectively. The feasibility of performing a genetic evaluation of HD across countries was indicated by the favourable genetic correlations estimated between score modes (ranged from 0.48 to 0.99). The accuracy of selection for the most recent birth year cohorts of male dogs was not improved by international evaluation compared to national evaluation. Improvement in genetic progress can however be achieved by selection across populations in different countries, particularly for small populations, which were indicated by the large difference between selection differentials based on the national and international evaluations.


Subject(s)
Hip Dysplasia, Canine/genetics , Animals , Breeding , Dogs , France , Hip Dysplasia, Canine/diagnosis , Inheritance Patterns , Male , Pedigree , Phenotype , Species Specificity , Sweden , United Kingdom
16.
J Anim Breed Genet ; 134(2): 152-161, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27862377

ABSTRACT

Merging pedigree databases across countries may improve the ability of kennel organizations to monitor genetic variability and health-related issues of pedigree dogs. We used data provided by the Société Centrale Canine (France), Svenska Kennelklubben (Sweden) and the Kennel Club (UK) to study the feasibility of merging pedigree databases across countries and describe breeding practices and international gene flow within the following four breeds: Bullmastiff (BMA), English setter (ESE), Bernese mountain dog (BMD) and Labrador retriever (LBR). After merging the databases, genealogical parameters and founder contributions were calculated according to the birth period, breed and registration country of the dogs. Throughout the investigated period, mating between close relatives, measured as the proportion of inbred individuals (considering only two generations of pedigree), decreased or remained stable, with the exception of LBR in France. Gene flow between countries became more frequent, and the origins of populations within countries became more diverse over time. In conclusion, the potential to reduce inbreeding within purebred dog populations through exchanging breeding animals across countries was confirmed by an improved effective population size when merging populations from different countries.


Subject(s)
Dogs/classification , Dogs/genetics , Animals , Biological Evolution , Breeding , Databases, Genetic , Dogs/physiology , Female , France , Male , Pedigree , Sweden , United Kingdom
17.
J Anim Sci ; 94(12): 5055-5063, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28046135

ABSTRACT

This study investigates the relationships between various environmental and geographic, demographic, and socioeconomic factors with the diversity of livestock breeds reported within countries across the world. Statistical analyses were performed considering the numbers of breeds reported by 158 countries for 4 livestock mammalian species (cattle, sheep, goats, and pigs). Organization for Economic Cooperation and Development (OECD) countries reported more breeds than non-OECD countries in general. Strong and positive correlations were found between agricultural area, human population size, species population size, and number of breeds per country. When considering regression models, the species population size was found as the most important explanatory factor for the number of breeds reported by countries in the 4 species. Diversity of production systems in the country had a significant association with the number of breeds reported for sheep, goats, and pigs. The number of ruminant breeds was positively associated with the size of agricultural area and the diversity of land cover in the country. While demographic and cultural importance of a given species is a major factor associated with the number of livestock breeds within countries, this diversity is also connected to the variability in environmental and production conditions.


Subject(s)
Cattle/genetics , Goats/genetics , Sheep/genetics , Swine/genetics , Agriculture , Animals , Breeding , Demography , Environment , Genetic Variation , Geography , Humans , Livestock , Population Density , Principal Component Analysis , Regression Analysis , Socioeconomic Factors
18.
Animal ; 10(2): 262-73, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26503101

ABSTRACT

Crossbreeding, considering either terminal or rotational crossing, synthetic breed creation or breed replacement, is often promoted as an efficient strategy to increase farmers' income through the improvement of productivity of local livestock in developing countries. Sustainability of crossbreeding is however frequently challenged by constraints such as poor adaptation to the local environment or lack of logistic support. In this review, we investigate factors that may influence the long-term success or the failure of crossbreeding programs, based on the scientific literature and country reports submitted for The Second Report on the State of the World's Animal Genetic Resources for Food and Agriculture. Crossbreeding activities vary widely across species and countries. Its sustainability is dependent on different prerequisites such as continual access to adequate breeding stock (especially after the end of externally funded crossbreeding projects), the opportunity of improved livestock to express their genetic potential (e.g. through providing proper inputs) and integration within a reliable market chain. As formal crossbreeding programs are often associated with adoption of other technologies, they can be a catalyst for innovation and development for smallholders. Given the increasing global demand for animal products, as well as the potential environmental consequences of climate change, there is a need for practical research to improve the implementation of long-term crossbreeding programs in developing countries.


Subject(s)
Animal Husbandry/economics , Animals, Domestic , Developing Countries , Hybridization, Genetic , Animal Husbandry/methods , Animals , Breeding/economics , Breeding/methods , Cattle , Chickens , Developing Countries/economics , Goats , Sheep , Swine
19.
Microbiology (Reading) ; 162(2): 256-267, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26581883

ABSTRACT

Whole genome sequencing of the response of Porphyromonas gingivalis W83 to hydrogen peroxide revealed an upregulation of several uncharacterized, novel genes. Under conditions of prolonged oxidative stress in P. gingivalis, increased expression of a unique transcriptional unit carrying the grpE, dnaJ and three other hypothetical genes (PG1777, PG1778 and PG1779) was observed. The transcriptional start site of this operon appears to be located 91 bp upstream of the translational start, with a potential -10 region at -3 nt and a -35 region at -39 nt. Isogenic P. gingivalis mutants FLL273 (PG1777 : : ermF-ermAM) and FLL293 (PG1779 : : ermF-ermAM) showed increased sensitivity to and decreased survival after treatment with hydrogen peroxide. P. gingivalis FLL273 showed a fivefold increase in the formation of spontaneous mutants when compared with the parent strain after exposure to hydrogen peroxide. The recombinant PG1777 protein displayed iron-binding properties when incubated with FeSO4 and Fe(NH4)2(SO4).6H2O. The rPG1777 protein protected DNA from degradation when exposed to hydrogen peroxide in the presence of iron. Taken together, the data suggest that the grpE-dnaJ-PG1777-PG1778-PG1779 transcriptional unit may play an important role in oxidative stress resistance in P. gingivalis via its ability to protect against DNA damage.


Subject(s)
Hydrogen Peroxide/pharmacology , Iron-Binding Proteins/metabolism , Oxidative Stress/physiology , Porphyromonas gingivalis/genetics , DNA Damage/drug effects , Gene Expression Regulation, Bacterial , Microbial Sensitivity Tests , Multigene Family/genetics , Oxidative Stress/drug effects , Porphyromonas gingivalis/drug effects , Transcription, Genetic/genetics
20.
Anim Genet ; 47(2): 141-53, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26662214

ABSTRACT

Preservation of specific and inheritable phenotypes of current or potential future importance is one of the main purposes of conservation of animal genetic resources. In this review, we investigate the issues behind the characterisation, utilisation and conservation of rare phenotypes, considering their multiple paths of relevance, variable levels of complexity and mode of inheritance. Accurately assessing the rarity of a given phenotype, especially a complex one, is not a simple task, because it requires the phenotypic and genetic characterisation of a large number of animals and populations and remains dependent of the scale of the study. Once characterised, specific phenotypes may contribute to various purposes (adaptedness, production, biological model, aesthetics, etc.) with adequate introgression programmes, which justifies the consideration of (real or potential) existence of such characteristics in in situ or ex situ conservation strategies. Recent biotechnological developments (genomic and genetic engineering) will undoubtedly bring important changes to the way phenotypes are characterised, introgressed and managed.


Subject(s)
Animals, Domestic/genetics , Genetic Variation , Phenotype , Agriculture , Animals , Biotechnology , Breeding , Conservation of Natural Resources , Genetic Engineering , Inheritance Patterns
SELECTION OF CITATIONS
SEARCH DETAIL
...