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Background: This study examined whether cultural factors, as compared to geographical distance, have produced a population sub-structure among different groups from the La Guajira population (Amerindian Wayúu and other resident groups) that co-exist within the same region. Aims: The aims of this study were to analyse this population to discover whether cultural barriers result in the sub-structure, to evaluate whether there is a genetic drift effect and to describe migration dynamics using a genetic, genealogical and demographic approach. Subjects: This study examined a sample of 290 individuals who were grouped based on a genealogical criterion to distinguish between native individuals and migrants. Materials and methods: Using demographic information, the age and gender structure of the population and genetic drift estimators were analysed. Using 15 autosomal microsatellites, heterozygosity, Hardy-Weinberg equilibrium (HWE), inbreeding, sub-structure, recent migration rate and genetic relationships were also evaluated using a Principal Component analysis (PCA) using reference populations. Results: La Guajira is a young population that is growing and exposed to a moderate effect of genetic drift ( Neme 11.903). The Wayúu are highly diverse ( Ho 0.727) and different from other groups, with the exception of Wayúu-Guajiro. This trend was also observed in other Amerindian populations. Conclusion: This study found a high level of admixture and gene flow within the Wayúu population despite cultural differences. Thus, although the Wayúu population differs from other population groups, it is not an isolated population. [ABSTRACT FROM AUTHOR]

The Brahman is one of the most popular breeds for meat production in the Neotropics. However, genetic studies of the breed in Latin American countries have only recently begun. In total, 178 animals of the Brahman breed from 20 Colombian provinces were genotyped at 11 microsatellite markers with the aim of studying the genetic diversity of this population and its genetic relationships with zebuine and taurine breeds. The outcomes of multivariate analyses, Bayesian inferences and inter-individual genetic distances suggested that there is no genetic sub-structure in the population, because of the high rate of animal migration among provinces. The population shows a high degree of heterozygosity and allelic diversity compared with other breeds, reflecting its multibreed origin. The study of the genetic relationships among the breeds reveals that the Brahman breed belongs to the zebuine group. However, it is the population nearest to taurine breeds with high frequencies of taurine alleles. Intensive artificial selection may have favoured the taurine alleles after the breed was formed. There has also been some degree of mixture with local taurine breeds while the Brahman breed has evolved in Colombia. [ABSTRACT FROM AUTHOR]

Se indujeron procesos primarios de morfogénesis de novo vía organogénesis indirecta en segmentos de hipocótilo de abarco, provenientes de plántulas in vitro de dos semanas de edad. El material fuente se obtuvo por germinación de embriones en Woody Plant Médium (WPM) diluido a la mitad y sin reguladores de crecimiento. La formación de callo or­ganogénico se estimuló mediante la adición de ácido indolacético (AIA) conjuntamente con 6-bencilami­nopurina (BAP). Después de cuatro semanas el mayor porcentaje de formación de callo (75%) se observó con la combinación AIA 1,21 μM y BAP 7,6 μM.

Coronavirus disease 2019 (COVID-19) was considered a major public health burden worldwide. Multiple studies have shown that susceptibility to severe infections and the development of long-term symptoms is significantly influenced by viral and host factors. These findings have highlighted the potential of host genetic markers to identify high-risk individuals and develop target interventions to reduce morbimortality. Despite its importance, genetic host factors remain largely understudied in Latin-American populations. Using a case-control design and a custom next-generation sequencing (NGS) panel encompassing 81 genetic variants and 74 genes previously associated with COVID-19 severity and long-COVID, we analyzed 56 individuals with asymptomatic or mild COVID-19 and 56 severe and critical cases. In agreement with previous studies, our results support the association between several clinical variables, including male sex, obesity and common symptoms like cough and dyspnea, and severe COVID-19. Remarkably, thirteen genetic variants showed an association with COVID-19 severity. Among these variants, rs11385942 (p < 0.01; OR = 10.88; 95% CI = 1.36-86.51) located in the LZTFL1 gene, and rs35775079 (p = 0.02; OR = 8.53; 95% CI = 1.05-69.45) located in CCR3 showed the strongest associations. Various respiratory and systemic symptoms, along with the rs8178521 variant (p < 0.01; OR = 2.51; 95% CI = 1.27-4.94) in the IL10RB gene, were significantly associated with the presence of long-COVID. The results of the predictive model comparison showed that the mixed model, which incorporates genetic and non-genetic variables, outperforms clinical and genetic models. To our knowledge, this is the first study in Colombia and Latin-America proposing a predictive model for COVID-19 severity and long-COVID based on genomic analysis. Our study highlights the usefulness of genomic approaches to studying host genetic risk factors in specific populations. The methodology used allowed us to validate several genetic variants previously associated with COVID-19 severity and long-COVID. Finally, the integrated model illustrates the importance of considering genetic factors in precision medicine of infectious diseases., (© 2024. The Author(s).)

Current human populations are studied to elucidate their ancestry composition and to obtain reference values for an array of genetic markers for forensic practice. This study compared the 79 ancestry informative markers (AIMs) panel with the SNPforID 52plex set used in forensic identification, using samples belonging to Continental Caribbean populations from Colombia with a high percentage of locals self-determined as Native American descendants. The results show a bias in the individual estimation made with the identification markers, which disregards the Native American ancestry component and overestimates the African ancestry component. Also, the analysis made with the Bayesian Classification Algorithm shows better likelihoods for individual assignment with AIMs than with SNPforID 52plex., Competing Interests: Conflict of interest Authors declare no financial and commercial conflicts of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Heteropaternal superfecundation is an extremely rare phenomenon that occurs when a second ova released during the same menstrual cycle is additionally fertilized by the sperm cells of a different man in separate sexual intercourse. In August, 2018, the Grupo de Genética de Poblaciones e Identificación at Universidad Nacional de Colombia received a request to establish the paternity of a pair of male twins with genetic markers. The following analyses were performed: amelogenin gene, autosomal short tandem repeat (STR), and Y-STR analyses by means of human identification commercial kits, paternity index, and the probability of paternity calculation and interpretation. A paternity index of 2.5134E+7 and a probability of paternity of 99.9999% for twin 2 were obtained while 14 out of 17 Y-chromosome markers and 14 out of 21 autosomal short tandem repeats were excluded for twin 1. The results indicated that the twins have different biological fathers. Although heteropaternal superfecundation is rarely observed among humans given its low frequency, in paternity disputes for dizygotic twins it is mandatory to demand the presence of the two twins in the testing to avoid wrong conclusions.

Colombia, located in the north of the South American subcontinent is a country of great interest for population genetic studies given its high ethnic and cultural diversity represented by the admixed population, 102 indigenous peoples and African descent populations. In this study, an analysis of the genetic structure and ancestry was performed based on 46 ancestry informative INDEL markers (AIM-INDELs) and considering the genealogical and demographic variables of 451 unrelated individuals belonging to nine Native American, two African American, and four multiple ancestry populations. Measures of genetic diversity, ancestry components, and genetic substructure were analyzed to build a population model typical of the northernmost part of the South American continent. The model suggests three types of populations: Native American, African American, and multiple ancestry. The results support hypotheses posed by other authors about issues like the peopling of South America and the existence of two types of Native American ancestry. This last finding could be crucial for future research on the peopling of Colombia and South America in that a single origin of all indigenous communities should not be assumed. It then would be necessary to consider other events that could explain their genetic variability and complexity throughout the continent., (© 2020 Wiley Periodicals LLC.)

In most cases, male sexual differentiation occurs with SRY gene mediation. However, exceptional genotypes have been identified, as shown in this paper. This was a male adult patient seen at the Servicio de Paternidades, Instituto de Genética, Universidad Nacional de Colombia. The following procedures were carried out: Amelogenin gene and short tandem repeat analyses using human identification commercial kits, conventional karyotype, SRY fluorescent in situ hybridization, PCR analysis for Y chromosome microdeletions, clinical evaluation, and genetic counseling. We present an adult male with unambiguous genitalia, karyotype 46,XX, and an SRY negative and ZFY positive molecular profile. The diagnosis of nonsyndromic 46,XX testicular disorder of sex development (DSD) -a rare genetic condition- was established. Only 20 % of similarly diagnosed patients are SRY negative and exhibit diverse molecular profiles. Until now, available evidence seems to indicate that, even in the absence of SRY, the ZFY factor is involved in male sexual differentiation.

The emergence of Massively Parallel Sequencing technologies enabled the analysis of full mitochondrial (mt)DNA sequences from forensically relevant samples that have, so far, only been typed in the control region or its hypervariable segments. In this study, we evaluated the performance of a commercially available multiplex-PCR-based assay, the Precision ID mtDNA Whole Genome Panel (Thermo Fisher Scientific), for the amplification and sequencing of the entire mitochondrial genome (mitogenome) from even degraded forensic specimens. For this purpose, more than 500 samples from 24 different populations were selected to cover the vast majority of established superhaplogroups. These are known to harbor different signature sequence motifs corresponding to their phylogenetic background that could have an effect on primer binding and, thus, could limit a broad application of this molecular genetic tool. The selected samples derived from various forensically relevant tissue sources and were DNA extracted using different methods. We evaluated sequence concordance and heteroplasmy detection and compared the findings to conventional Sanger sequencing as well as an orthogonal MPS platform. We discuss advantages and limitations of this approach with respect to forensic genetic workflow and analytical requirements., (Copyright © 2019. Published by Elsevier B.V.)

The valley of the Magdalena River is one of the main population pathways in Colombia. The gene pool and spatial configuration of human groups in this territory have been outlined throughout three historical stages: the Native pre-Hispanic world, Spanish colonization, and XIX century migrations. This research was designed with the goal of characterizing the diversity and distribution pattern of Y-chromosome lineages that are currently present in the Tolima and Huila departments (middle Magdalena River region). Historic cartography was used to identify the main geographic sites where the paternal lineages belonging to this area have gathered. Twelve municipalities were chosen, and a survey that included genealogical information was administered. Samples collected from 83 male volunteers were analyzed for 48 Y-SNPs and 17 Y-STRs. The results showed a highly diverse region characterized by the presence of 16 sublineages within the major clades R, Q, J, G, T and E and revealed that 93% (n = 77) of haplotypes were different. Among these haplogroups, European-specific R1b-M269 lineages were the most representative (57.83%), with six different subhaplogroups and 43 unique haplotypes. Native American paternal ancestry was also detected based on the presence of the Q1a2-M3*(xM19, M194, M199) and Q1a2-M346*(xM3) lineages. Interestingly, all Q1a2-M346*(xM3) samples (n = 7, with five different haplotypes) carried allele six at the DYS391 locus. This allele has a worldwide frequency of 0.169% and was recently associated with a new Native subhaplogroup. An in-depth phylogenetic analysis of these samples suggests the Tolima and Huila region to be the principal area in all Central and South America where this particular Native lineage is found. This lineage has been present in the region for at least 1,809 (+/- 0,5345) years., Competing Interests: The authors have declared that no competing interests exist.

The Archipelago of San Andrés and Providencia is a Colombian Department in the western waters of the Caribbean Sea. Most of its inhabitants belong to the African-Colombian group known as raizal. This group has unique cultural traits that are derived from centuries of admixture of the primarily African slaves and European colonists. Currently, not much is known about the genetic profile of this population. Therefore, this study aimed to determine the Y-chromosome STR genetic structure and relationship to previously published reference populations. A total of 54 natives from the islands were selected based on the genealogical criterion of having three generations of ancestors born in the Archipelago. Seventeen Y-STRs were analyzed, supplemented by information on the first surname inherited. The genetic substructure hypothesis in the studied islands was tested, and no significant differences were found (p>0.05). Y-chromosome haplogroups were predicted, and E1b1a and R1b were the most commonly found haplogroups. They account for more than 80% of the sample. The E1b1a and R1ba haplogroups are common in the African and European populations, respectively. For comparative genetic analysis, genetic distances were calculated with respect to populations from the Caribbean, Colombia, Europe and Africa. We found greater similarity between the African and Caribbean populations. The surname analysis demonstrated that most of the time, the "raizales" with the same surname also shared the same Y-STR haplotype. This suggests that some kinship relationship exists between participants with the same surname, which was confirmed by the haplotype diversity levels found in the studied islands., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

The main objective of this work was to examine the succession of insects colonizing three pig (Sus scrofa) cadavers in a semi-rural area of Bogotá. The 12kg pigs were shot and put into metallic mesh cages to allow access by insects. Arthropods were then sampled at different intervals depending on the corresponding stage of decomposition. In total 5981 arthropods were collected during decomposition, 3382 adults and 2599 immature stages, belonging to 10 orders and 27 families. Sarconesia magellanica and Compsomyiops verena (Diptera: Calliphoridae) were the first species to colonize the corpses. Egg masses and 1st stage Calliphoridae larvae were associated with the fresh stage of decomposition, 1st and 2nd stage larvae of Calliphoridae and Sarcophagidae during chromatic and emphysematous stages, immature Chrysomya albiceps (Diptera: Calliphoridae), Ophyra sp. (Diptera: Muscidae) and Oxellytrum discicolle (Coleoptera: Silphidae) during the colliquative stage and mainly Coleoptera during the skeletization phase (plus some adult Diptera). The data obtained in the present investigation could be used for the estimation of postmortem interval (PMI) in real cases when the conditions to which a cadaver has been exposed are similar to those recorded during this work.

We present information from populations living in Bogotá and Boyacá, for nine short tandem repeats (STR's) already studied and four new alleles not reported in previous Colombian populations.