Transient loss of Polycomb components induces an epigenetic cancer fate.

Although cancer initiation and progression are generally associated with the accumulation of somatic mutations1,2, substantial epigenomic alterations underlie many aspects of tumorigenesis and cancer susceptibility3-6, suggesting that genetic mechanisms might not be the only drivers of malignant transformation7. However, whether purely non-genetic mechanisms are sufficient to initiate tumorigenesis irrespective of mutations has been unknown. Here, we show that a transient perturbation of transcriptional silencing mediated by Polycomb group proteins is sufficient to induce an irreversible switch to a cancer cell fate in Drosophila. This is linked to the irreversible derepression of genes that can drive tumorigenesis, including members of the JAK-STAT signalling pathway and zfh1, the fly homologue of the ZEB1 oncogene, whose aberrant activation is required for Polycomb perturbation-induced tumorigenesis. These data show that a reversible depletion of Polycomb proteins can induce cancer in the absence of driver mutations, suggesting that tumours can emerge through epigenetic dysregulation leading to inheritance of altered cell fates.

The KNee OsteoArthritis Prediction (KNOAP2020) challenge: An image analysis challenge to predict incident symptomatic radiographic knee osteoarthritis from MRI and X-ray images.

OBJECTIVES: The KNee OsteoArthritis Prediction (KNOAP2020) challenge was organized to objectively compare methods for the prediction of incident symptomatic radiographic knee osteoarthritis within 78 months on a test set with blinded ground truth. DESIGN: The challenge participants were free to use any available data sources to train their models. A test set of 423 knees from the Prevention of Knee Osteoarthritis in Overweight Females (PROOF) study consisting of magnetic resonance imaging (MRI) and X-ray image data along with clinical risk factors at baseline was made available to all challenge participants. The ground truth outcomes, i.e., which knees developed incident symptomatic radiographic knee osteoarthritis (according to the combined ACR criteria) within 78 months, were not provided to the participants. To assess the performance of the submitted models, we used the area under the receiver operating characteristic curve (ROCAUC) and balanced accuracy (BACC). RESULTS: Seven teams submitted 23 entries in total. A majority of the algorithms were trained on data from the Osteoarthritis Initiative. The model with the highest ROCAUC (0.64 (95% confidence interval (CI): 0.57-0.70)) used deep learning to extract information from X-ray images combined with clinical variables. The model with the highest BACC (0.59 (95% CI: 0.52-0.65)) ensembled three different models that used automatically extracted X-ray and MRI features along with clinical variables. CONCLUSION: The KNOAP2020 challenge established a benchmark for predicting incident symptomatic radiographic knee osteoarthritis. Accurate prediction of incident symptomatic radiographic knee osteoarthritis is a complex and still unsolved problem requiring additional investigation.

Opinions, Attitudes, and Perceptions in Relation to Erectile Dysfunction and Premature Ejaculation in the Undiagnosed Spanish Male Population. Results of the PANDORA Project.

BACKGROUND: Approximately 43% of Spanish men report experiencing premature ejaculation (PE) at some point in their lives and 12.1% suffer from erectile dysfunction (ED), of whom only 16.5% have seen a doctor. Despite this, ED and PE remain undiagnosed among a supposedly healthy segment of the population. AIM: To assess the general knowledge of a representative population of healthy Spanish males of the symptoms, treatment, and expectations related to ED and PE. METHODS: This was a descriptive study based on an online questionnaire in which 2,515 males aged 25-75 years with no history of ED and/or PE presented their perception of aspects related to symptoms, diagnosis, treatment, and expectations in ED and PE. MAIN OUTCOME MEASURES: The study provided an evaluation of the knowledge, attitude, and underdiagnosis of ED and/or PE in healthy males and the approach taken by urology specialists and other disciplines. RESULTS: The survey was completed by 2,515 healthy males, including over 80% of those who had completed secondary or higher education. 60% of the sample had never seen a urologist and 59% and 62% of the participating men responded correctly to the statements about PE and ED, respectively. Their lack of knowledge of the therapeutic alternatives was clear (74% and 76% of the panel were unaware of the existence of effective treatments for ED and PE, respectively). Despite the initiative shown by some participants in seeking information about each condition (10.3% for ED; 16.7% for PE), only 4.7% of them had been questioned about ED by a medical practitioner (1.9% for PE). The underdiagnosis rate stood at 3.5% for ED (5.6% participants >65 years) and at about 10% for PE. CLINICAL IMPLICATIONS: These results will represent a point of departure for establishing some recommendations to improve the detection and treatment of these disorders. STRENGTHS & LIMITATIONS: This is the first study of its kind in Spain to analyze the underdiagnosis of ED and/or PE inferred from data reported by a population of healthy males. Screening for ED was performed with a validated questionnaire. However, the rest of the research was conducted using adaptations of validated questionnaires or a self-designed questionnaire based on and in consultation with a group of experienced andrologists. CONCLUSION: People need to have greater knowledge of both the conditions and the related false myths to make sure that they are familiar with the existence of drug treatments and socio-sanitary interventions. Primary care physicians and urologists should also be more proactive in routine visits in order to achieve better management of ED and PE. Prieto-Castro R, Puigvert-Martínez AM, Artigas-Feliu R, et al. Opinions, Attitudes, and Perceptions in Relation to Erectile Dysfunction and Premature Ejaculation in the Undiagnosed Spanish Male Population. Results of the PANDORA Project. J Sex Med 2020;17:1495-1508.

Papillary thyroid microcarcinoma with minimal extrathyroidal extension. Has it so indolent course to require a less aggressive treatment? / Microcarcinoma papilar de tiroides con extensión extratiroidea mínima. ¿Tiene un curso tan indolente para precisar un tratamiento menos intensivo?

BACKGROUND: Although the incidence of papillary thyroid microcarcinoma (PTMC) has increased in recent decades, the role played by minimal extrathyroidal extension (mETE) in the prognosis of PTMC is still unclear. The aim of this study is to analyse the factors associated with PTMC and mETE and the long-term prognosis of PTMC. MATERIAL AND METHODS: We conducted a retrospective study with a population consisting of patients with a histological diagnosis of PTMC. We excluded patients who had previously undergone thyroid surgery, those who had other synchronous malignancies, those with an ectopic location of the PTMC and those lost to follow-up within 2years. We compared group 1 (PTMC without extrathyroidal extension) versus group 2 (PTMC with mETE) and performed a multivariate analysis. RESULTS: We observed PTMC with mETE in 11.2% (n=18) of the patients. In the multivariate analysis, mETE was associated with an age ≥45 years (OR, 4.383; 95% CI 1.051-18.283, p=.043), a tumour size ≥8mm (OR, 5.913; 95% CI 1.795-19.481; p=.003), bilaterality (OR, 4.430; 95% CI 1.294-15.173; p=.018) and metastatic lymph nodes (OR, 12.588; 95% CI 2.919-54.280; p=.001). During a mean follow-up of 119.8±65 months, one recurrence was detected in group 2 (0% vs. 5.6%; p=.112), but none of the patients died due to the disease. Disease-free survival was lower in group 2 (124.9±5.6 vs. 97.4±10.3 months; p=.034). CONCLUSIONS: The mETE of MCPT is a factor of worse prognosis, associated with the presence of metastatic lymph nodes and lower disease-free survival.

Trends in depression prevalence in the USA from 2005 to 2015: widening disparities in vulnerable groups.

BACKGROUND: Major depression is associated with significant disability, morbidity, and mortality. The current study estimated trends in the prevalence of major depression in the US population from 2005 to 2015 overall and by demographic subgroups. METHODS: Data were drawn from the National Survey on Drug Use and Health (NSDUH), an annual cross-sectional study of US persons ages 12 and over (total analytic sample N = 607 520). Past-year depression prevalence was examined annually among respondents from 2005 to 2015. Time trends in depression prevalence stratified by survey year were tested using logistic regression. Data were re-analyzed stratified by age, gender, race/ethnicity, income, and education. RESULTS: Depression prevalence increased significantly in the USA from 2005 to 2015, before and after controlling for demographics. Increases in depression were significant for the youngest and oldest age groups, men, and women, Non-Hispanic White persons, the lowest income group, and the highest education and income groups. A significant year × demographic interaction was found for age. The rate of increase in depression was significantly more rapid among youth relative to all older age groups. CONCLUSIONS: The prevalence of depression increased significantly in the USA from 2005 to 2015. The rate of increase in depression among youth was significantly more rapid relative to older groups. Further research into understanding the macro level, micro level, and individual factors that are contributing to the increase in depression, including factors specific to demographic subgroups, would help to direct public health prevention and intervention efforts.

Neural mechanisms of mismatch negativity dysfunction in schizophrenia.

Schizophrenia is associated with cognitive deficits that reflect impaired cortical information processing. Mismatch negativity (MMN) indexes pre-attentive information processing dysfunction at the level of primary auditory cortex. This study investigates mechanisms underlying MMN impairments in schizophrenia using event-related potential, event-related spectral decomposition (ERSP) and resting state functional connectivity (rsfcMRI) approaches. For this study, MMN data to frequency, intensity and duration-deviants were analyzed from 69 schizophrenia patients and 38 healthy controls. rsfcMRI was obtained from a subsample of 38 patients and 23 controls. As expected, schizophrenia patients showed highly significant, large effect size (P=0.0004, d=1.0) deficits in MMN generation across deviant types. In ERSP analyses, responses to deviants occurred primarily the theta (4-7 Hz) frequency range consistent with distributed corticocortical processing, whereas responses to standards occurred primarily in alpha (8-12 Hz) range consistent with known frequencies of thalamocortical activation. Independent deficits in schizophrenia were observed in both the theta response to deviants (P=0.021) and the alpha-response to standards (P=0.003). At the single-trial level, differential patterns of response were observed for frequency vs duration/intensity deviants, along with At the network level, MMN deficits engaged canonical somatomotor, ventral attention and default networks, with a differential pattern of engagement across deviant types (P<0.0001). Findings indicate that deficits in thalamocortical, as well as corticocortical, connectivity contribute to auditory dysfunction in schizophrenia. In addition, differences in ERSP and rsfcMRI profiles across deviant types suggest potential differential engagement of underlying generator mechanisms.

Stress-related hormonal alterations, growth and pelleted starter intake in pre-weaning Holstein calves in response to thermal stress.

This study aimed to investigate the effect of heat stress and month of birth on growth performance, pelleted starter intake, and stress-related hormones in Holstein calves. Birth weight and growth records, representing 4735 Holstein calves from a large commercial dairy herd in northern Mexico (25° N; 22.3 °C mean annual temperature) from 2013 to 2015, were analyzed. Temperature-humidity index (THI) at calving, season of birth, and month of birth were the independent variables, whereas growth traits were the dependent variables. Increased THI at birth from < 65 to > 85 units was associated with a decrease in birth weight from 39.3 to 38.7 kg. Calves subjected to high THI (> 75 units) at calving showed lesser (P < 0.01) pre-weaning gains (405 ± 97 g/calf/day), whereas those calves born with THI < 70 units presented the highest gains (466 ± 112 g/calf/day). Birth during the fall months reduced (P < 0.01) weaning weight by about 5 kg compared with winter months. Also, the pre-weaning average daily gain for calves born in the fall was about 70 g less (P < 0.01) than calves delivered in winter months. Plasma triiodothyronine and tetraiodothyronine levels were lower (1.02 ± 0.21 and 48 ± 7.9 ng/mL, respectively; P < 0.01) in summer and highest in winter (1.64 ± 0.48 and 66 ± 11 ng/mL, respectively). Mean plasma cortisol concentration was higher in heat-stressed calves born in summer (59 ± 40 ng/mL) than calves born in winter (20 ± 28 ng/mL). Pelleted starter intake 1 week before weaning was lowest (P < 0.01) in the fall (0.82 ± 0.26 kg/calf/day; mean ± SD) and highest in spring (1.26 ± 0.43 kg/calf/day). It was concluded that in this particular environment, heat stress affects birth weight and growth rate of Holstein calves. Thus, environmental management of the newborn calf during hot spring and summer months is warranted to optimize pelleted starter intake and calf growth rates.

The legacy of Columbus in American horse populations assessed by microsatellite markers.

Criollo horse populations descend from horses brought from the Iberian Peninsula over the period of colonization (15th to 17th century). They are spread throughout the Americas and have potentially undergone genetic hybridization with other breeds in the recent past. In this study, 25 autosomal microsatellites were genotyped in 50 horse breeds representing Criollo populations from 12 American countries (27 breeds), breeds from the Iberian Peninsula (19), one breed each from France and Morocco and two cosmopolitan horse breeds (Thoroughbred and Arabian). The genetic relationships among breeds identified five clusters: Celtic; Iberian; North American with Thoroughbred influence; most Colombian breeds; and nearly all other Criollo breeds. The group of "all other Criollo breeds" had the closest genetic relationship with breeds originating from the Iberian Peninsula, specifically with the Celtic group. For the whole set of Criollo breeds analysed, the estimated genetic contribution from other breeds was approximately 50%, 30% and 20% for the Celtic, Iberian and Arab-Thoroughbred groups, respectively. The spatial distribution of genetic diversity indicates that hotspots of genetic diversity are observed in populations from Colombia, Ecuador, Brazil, Paraguay and western United States, possibly indicating points of arrival and dispersion of Criollo horses in the American continent. These results indicate that Criollo breeds share a common ancestry, but that each breed has its own identity.

Pediatric Allergic Contact Dermatitis: Clinical and Epidemiological Study in a Tertiary Hospital. / Dermatitis alérgica de contacto pediátrica. Estudio clínico-epidemiológico en un hospital terciario.

BACKGROUND: Few epidemiological studies have investigated the incidence of allergic contact dermatitis in children. Underdiagnosis has been observed in some studies, with many cases in which the condition is not suspected clinically and patch tests are not performed. However, the prevalence of pediatric sensitization to allergens has been reported to be as high as 20%, and the diagnosis should therefore be contemplated as a possibility in this age group. MATERIAL AND METHODS: We performed a retrospective analysis of the skin allergy database of the Dermatology Department of Consorcio Hospital General Universitario de Valencia. Children between 0 and 16 years of age diagnosed with allergic contact dermatitis in the previous 15 years (between 2000 and 2015) were included in the analysis. Epidemiological (age, sex, history of atopy) and clinical (site of the lesions, allergen series applied, positive reactions, and their relevance) variables were gathered. RESULTS: Patch tests had been performed on 4,593 patients during the study period. Of these, 265 (6%) were children aged between 0 and 16 years. A positive reaction to at least one of the allergens tested was observed in 144 (54.3%) patients in that group. The allergens most frequently identified were the following (in decreasing order of frequency): thiomersal, cobalt chloride, colophony, paraphenylenediamine, potassium dichromate, mercury, and nickel. The sensitization was considered relevant in 177 (61.3%) cases. CONCLUSIONS: More than half of the children studied showed sensitization to 1 or more allergens, with a high percentage of relevant sensitizations. All children with a clinical suspicion of allergic contact dermatitis should be referred for patch testing. As no standardized test series have been developed for this age group, a high level of clinical suspicion and knowledge of the allergens most commonly involved are required when selecting the allergens to be tested.

Treatment of Bowen Disease With Photodynamic Therapy and the Advantages of Sequential Topical Imiquimod. / Tratamiento de la enfermedad de Bowen con terapia fotodinámica y ventajas de la aplicación secuencial de imiquimod tópico.

Photodynamic therapy (PDT) has been shown to be useful and effective in the treatment of actinic keratosis, Bowen disease, and basal cell carcinoma. We present a series of 13 Bowen disease lesions treated using PDT. Complete responses were achieved in 11 (84%) of the lesions after 3 months of treatment; at 18 months, complete responses were seen in 9 (70%) of the lesions. Patients who presented a partial response or recurrence were treated with topical 5% imiquimod and achieved complete responses. The lesions that presented partial response or recurrence were the largest lesions, between 3 and 5cm in diameter. PDT in monotherapy or combined sequentially with imiquimod is an excellent and well-tolerated therapeutic option for Bowen disease. The treatment has few adverse effects and shows satisfactory results, particularly in multiple large lesions in areas of difficult surgical reconstruction or in elderly patients with a high surgical risk.

Diagnosis of gynecological pseudoaneurysms and embolization with cyanoacrylate. / Diagnóstico y embolización con cianoacrilato de pseudoaneurismas de origen ginecológico.

Pseudoaneurysms of the uterine artery are an uncommon cause of severe gynecological bleeding secondary to surgical manipulation of the pelvis or to instrumental delivery. The different imaging techniques are of vital importance in the diagnosis. Angiography is the technique used for confirmation and also for treatment in many cases. Endovascular treatment by embolizing the pseudoaneurysm has become established as the treatment of choice, making it possible to avoid hysterectomy in women of childbearing age. This article presents two cases of gynecological bleeding due to pseudoaneurysms (one secondary to surgery and one secondary to childbirth) that were embolized in a novel way using cyanoacrylate.

Conservation priorities of Iberoamerican pig breeds and their ancestors based on microsatellite information.

Criollo pig breeds are descendants from pigs brought to the American continent starting with Columbus second trip in 1493. Pigs currently play a key role in social economy and community cultural identity in Latin America. The aim of this study was to establish conservation priorities among a comprehensive group of Criollo pig breeds based on a set of 24 microsatellite markers and using different criteria. Spain and Portugal pig breeds, wild boar populations of different European geographic origins and commercial pig breeds were included in the analysis as potential genetic influences in the development of Criollo pig breeds. Different methods, differing in the weight given to within- and between-breed genetic variability, were used in order to estimate the contribution of each breed to global genetic diversity. As expected, the partial contribution to total heterozygosity gave high priority to Criollo pig breeds, whereas Weitzman procedures prioritized Iberian Peninsula breeds. With the combined within- and between-breed approaches, different conservation priorities were achieved. The Core Set methodologies highly prioritized Criollo pig breeds (Cr. Boliviano, Cr. Pacifico, Cr. Cubano and Cr. Guadalupe). However, weighing the between- and within-breed components with FST and 1-FST, respectively, resulted in higher contributions of Iberian breeds. In spite of the different conservation priorities according to the methodology used, other factors in addition to genetic information also need to be considered in conservation programmes, such as the economic, cultural or historical value of the breeds involved.

Killer immunoglobulin-like receptor repertoire analysis in a Caucasian Spanish cohort with inflammatory bowel disease.

Immunological molecules are implicated in inflammatory disorders, including inflammatory bowel disease (IBD; Crohn disease [CD] and ulcerative colitis [UC]). Killer cell immunoglobulin-like receptors (KIRs) are also genetically variable proteins involved in immune function. They are expressed by NK cells and certain T lymphocytes, regulate specificity and function by interaction with HLA Class I molecules, may be either inhibitory or activating and are polymorphic both in terms of alleles and haplotype gene content. Genetic associations between activating KIRs and certain autoimmune and inflammatory diseases have been reported; however, a possible association between KIR and IBD remains unclear. The aim of this study was to determine the relationship between KIR repertoire and IBD pathologies in a Spanish cohort. KIR variability was analyzed using PCR-sequence specific oligonucleotide probes (SSOP). Inhibitory KIR2DL5 was found more frequently in UC and IBD patient groups than in healthy controls (P = 0.028 and P = 0.01, respectively), as was activating KIR2DS1 (P = 0.02, Pc > 0.05, UC vs. Controls; P = 0.001, Pc = 0.01, IBD vs Controls; P = 0.01, Pc > 0.05, Controls vs CR), KIR2DS5 (P = 0.0028, Pc = 0.04, Controls vs UC; P = 0.0001, Pc = 0.0017, Controls vs IBD; P = 0.01, Pc > 0.05, Controls vs CD) and KIR3DS1 (P = 0.012, Pc > 0.05, Controls vs IBD). Our data suggest that imbalance between activating and inhibitory KIR may partially explain the different pathogeneses of these IBDs and that there is a hypothetical role for the telomeric B region (which contains both KIR2DS5 and KIR2DS1) in these diseases.

Leukemia Cutis: A Report of 17 Cases and a Review of the Literature. / Leucemia cutis. Serie de 17 casos y revisión de la literatura.

Dermatologic manifestations of leukemia can be both specific and nonspecific (e.g., opportunistic infections, purpura and ecchymosis, Sweet syndrome). Leukemia cutis refers to the infiltration of the skin with neoplastic leukocytes and its early diagnosis has important prognostic implications. We report on 17 cases of leukemia cutis seen in our department between 1994 and 2014 and describe the characteristics of the patients (age, sex, medical history), the morphology of the lesions, and associations with systemic disease. Most of the patients were male and the most common associated malignancy was acute myeloid leukemia. The most frequent dermatologic manifestations were nodules or erythematous papules on the limbs. We describe our experience with the diagnosis and management of leukemia cutis over a period of 20 years and emphasize the importance of clinical signs in the early diagnosis of this condition.

[Clinical usefulness of ultrasound-guided alcohol sclerosis in patients with breast fistulas]. / Utilidad clínica de la esclerosis con alcohol guiada con ecografía en pacientes con fístulas de mama.

OBJECTIVE: To study the clinical usefulness of ultrasound-guided alcohol sclerosis as a treatment alternative to surgical intervention for breast fistulas. MATERIAL AND METHODS: This was a retrospective study of data collected in a hospital breast unit over a three-year period (January 2011 through December 2013). The procedure consists of introducing a sclerosing solution into the lumen of the breast fistula under ultrasound guidance. All cases were reviewed by a multidisciplinary committee; patients were offered ultrasound-guided alcohol sclerosis as a first treatment option with surgical intervention as a rescue therapy for those with unsatisfactory outcomes. RESULTS: Ten fistulas were treated in 9 women (median age, 33 y; interquartile range 18.5 y). Five patients (50%) attributed the clinical findings to recurrent mastitis, four (40%) to a previous surgical intervention, and one (10%) to lactation. Seven patients (78%) were smokers. The procedure was well tolerated: nine patients (90%) rated the pain as one or 2 (mild pain) on a visual analogue scale. There were no immediate complications. The response to treatment was considered excellent (absence of secretion and complete closure) in eight fistulas (80%). CONCLUSION: Ultrasound-guided alcohol sclerosis achieved excellent outcomes in 80% of cases and is a viable alternative to surgical treatment.

High prevalence of microplastics in the digestive tract of Scyliorhinus canicula (Linneaus, 1758) shows the species biomonitoring potential.

Plastic pollution is widespread in oceans and the ingestion of plastic by marine organisms is causing concern about potential adverse effects. The purpose of this study was to analyze the different types of plastics in the digestive tract of female small-spotted catshark (Scyliorhinus canicula). An alkaline digestion method using 10 % potassium hydroxide (KOH), was used. The samples were filtered and visually observed to classify the plastics according to size, shape, and color. Raman spectroscopy was further employed to identify the polymer types. The study found the presence of plastics in 89.5 % of the 200 females analyzed, including 10 polymers, with polystyrene (PS), polyamide-6 (PA6), polyvinyl chloride (PVC), and silicone rubber (SR) being the most common. The polymers identified largely reflect the results of similar studies in the marine environment and were similar to global polymer diversity of microplastics, which highlights the potential of S. canicula females for biomonitoring microplastic pollution.

Re-emergence of leishmaniasis in Spain: community outbreak in Madrid, Spain, 2009 to 2012.

Since July 2009, there has been a community outbreak of leishmaniasis in the south-west area of the Madrid autonomous community, Spain, affecting residents from four towns that are geographically close together and share extensive park areas. As of December 2012, 446 cases were reported (6 in 2009, 97 in 2010, 196 in 2011 and 147 in 2012), a mean incidence rate of 22.2 per 100,000 inhabitants during July 2009 and December 2012. The mean age was 44 years (range: 2 months to 95 years); 61.0% were male. A total of 68 (15.2%) had immunosuppressive conditions; 160 (35.9%) had visceral leishmaniasis and 286 (64.1%) cutaneous. A total of 421 (94.4%) cases were confirmed. Leishmania infantum was identified as the agent. Monitoring revealed high densities of the vector Phlebotomus perniciosus. The surveillance system for canine leishmaniasis did not detect any increase in prevalence during the period. Environmental control measures have been taken, such as improvements in sanitation and disinsection in the risk areas and control of the overpopulation of Leporidae, as xenodiagnosis studies have shown that hares play a role as active reservoirs. This is the largest reported community outbreak of leishmaniasis in Europe. The discovery of the new reservoir stands out in the multifactorial aetiology of the outbreak. Epidemiological research and environmental intervention measures are continuing.

Genetic diversity analysis of the Uruguayan Creole cattle breed using microsatellites and mtDNA markers.

The Uruguayan Creole cattle population (N = 600) is located in a native habitat in south-east Uruguay. We analyzed its genetic diversity and compared it to other populations of American Creole cattle. A random sample of 64 animals was genotyped for a set of 17 microsatellite loci, and the D-loop hyper-variable region of mtDNA was sequenced for 28 calves of the same generation. We identified an average of 5.59 alleles per locus, with expected heterozygosities between 0.466 and 0.850 and an expected mean heterozygosity of 0.664. The polymorphic information content ranged from 0.360 to 0.820, and the global FIS index was 0.037. The D-loop analysis revealed three haplotypes (UY1, UY2 and UY3), belonging to the European matriline group, with a haplotype diversity of 0.532. The history of the population, changes in the effective population size, bottlenecks, and genetic drift are possible causes of the genetic variability patterns that we detected.

Genetic characterization of Latin-American Creole cattle using microsatellite markers.

Genetic diversity in and relationships among 26 Creole cattle breeds from 10 American countries were assessed using 19 microsatellites. Heterozygosities, F-statistics estimates, genetic distances, multivariate analyses and assignment tests were performed. The levels of within-breed diversity detected in Creole cattle were considerable and higher than those previously reported for European breeds, but similar to those found in other Latin American breeds. Differences among breeds accounted for 8.4% of the total genetic variability. Most breeds clustered separately when the number of pre-defined populations was 21 (the most probable K value), with the exception of some closely related breeds that shared the same cluster and others that were admixed. Despite the high genetic diversity detected, significant inbreeding was also observed within some breeds, and heterozygote excess was detected in others. These results indicate that Creoles represent important reservoirs of cattle genetic diversity and that appropriate conservation measures should be implemented for these native breeds in order to minimize inbreeding and uncontrolled crossbreeding.