Bioinformatic identification of Single Nucleotide Polymorphisms (SNPs) in keratin-associated protein genes in alpacas (Vicugna pacos) / Identificación bioinformática de Polimorfismos de Nucleótido Simple (PNSs) en genes de proteínas asociadas a queratinas en alpacas (Vicugna pacos)

Abstract This study aims to identify single nucleotide polymorphisms (SNPs) within KRTAP genes in alpacas (Vicugna pacos), which play a fundamental role in defining their physico-mechanical properties and potentially the quality of alpaca fiber, the primary product of their breeding. Thirty-four KRTAP genes, as annotated in the reference genome VicPac3.1, were investigated. Utilizing the reference genome, along with nine additional genomes and reads from 300 reduced representation DNA libraries of alpacas, SNPs were identified. Minor allele frequency (MAF) and genotyping rates were computed using PLINK software, while Illumina Scores were determined for each SNP using Illumina Design Studio software. Markers meeting the criteria of MAF ≥ 0.05, genotyping rate > 45%, and Illumina Score ≥ 0.6 per SNP were selected. A total of 67 SNPs were identified within intronic, exonic, and untranslated regions of KRTAP genes. Among these, 35 SNPs were incorporated into the 76K Alpaca SNP microarray, with 32 SNPs subsequently validated in a population of 936 alpacas. In conclusion, our findings delineate SNPs within KRTAPs that hold potential utility in genome-wide association studies, thereby facilitating the integration of modern breeding technologies into alpaca breeding programs.

Resumen Este estudio tiene como objetivo identificar polimorfismos de nucleótido simple (PNSs) dentro de los genes KRTAP en alpacas (Vicugna pacos), que juegan un papel fundamental en la definición de sus propiedades físico-mecánicas y la calidad de la fibra de alpaca, producto principal de su crianza. Se investigaron treinta y cuatro genes KRTAP, tal como están anotados en el genoma de referencia VicPac3.1. Utilizando el genoma de referencia, junto con nueve genomas adicionales y lecturas de 300 bibliotecas de representación reducida de ADN de alpacas, se identificaron los PNSs. La frecuencia de los alelos menores (MAF) y las tasas de genotipificación se calcularon utilizando el software PLINK, mientras que los Illumina Score se determinaron para cada PNS utilizando el software Illumina Design Studio. Se seleccionaron marcadores que cumplían con los criterios de MAF ≥ 0.05, tasa de genotipado > 45% e Illumina Score ≥ 0.6 por PNS. Se identificaron un total de 67 PNSs dentro de regiones intrónicas, exónicas y/o no traducidas de genes KRTAP. Entre estos, se incorporaron 35 PNSs al microarray 76K Alpaca SNP, y posteriormente se validaron 32 PNSs en una población de 936 alpacas. En conclusión, nuestros hallazgos identificaron los PNSs dentro de los KRTAP que tienen una utilidad potencial en estudios de asociación de todo el genoma, facilitando así la integración de tecnologías de reproducción modernas en los programas de reproducción de alpacas.

Genome-Wide Association Study of Fiber Diameter in Alpacas.

The aim of this study was the identification of candidate genomic regions associated with fiber diameter in alpacas. DNA samples were collected from 1011 female Huacaya alpacas from two geographical Andean regions in Peru (Pasco and Puno), and three alpaca farms within each region. The samples were genotyped using an Affymetrix Custom Alpaca genotyping array containing 76,508 SNPs. After the quality controls, 960 samples and 51,742 SNPs were retained. Three association study methodologies were performed. The GWAS based on a linear model allowed us to identify 11 and 35 SNPs (-log10(p-values) > 4) using information on all alpacas and alpacas with extreme values of fiber diameter, respectively. The haplotype and marker analysis method allowed us to identify nine haplotypes with standardized haplotype heritability higher than six standard deviations. The selection signatures based on cross-population extended haplotype homozygosity (XP-EHH) allowed us to identify 180 SNPs with XP-EHH values greater than |3|. Four candidate regions with adjacent SNPs identified via two association methods of analysis are located on VPA6, VPA9, VPA29 and one chromosomally unassigned scaffold. This study represents the first analysis of alpaca whole genome association with fiber diameter, using a recently assembled alpaca SNP microarray.

Patrones de costos de atención a pacientes con enfermedades isquémicas del corazón en el Instituto Nacional Cardiovascular, 2019 / Cost patterns of care for patients with ischemic heart disease at the Instituto Nacional Cardiovascular, 2019

RESUMEN Introducción. La enfermedad isquémica del corazón (EIC) es actualmente un problema de salud pública en el Perú, y su tratamiento tiende a ser muy costoso para el sistema de salud. Objetivo. Establecer los patrones de costos de atención de las EIC en el Instituto Nacional Cardiovascular (INCOR) de la Seguridad Social en Salud del Perú (EsSalud). Métodos. Se utilizaron las bases de datos de atenciones, cirugías, egresos y valor bruto de la producción del INCOR de la población diagnosticada y atendida con EIC en el año 2019 (879 pacientes). Se estimaron los costos de las atenciones mediante costeo basado en actividad; se utilizó un modelo econométrico para establecer los determinantes de los costos, y con el método de distancia euclidiana se formaron "clústeres" con características similares para establecer patrones de costos. Resultados. El costo de atención de EIC más alto fue de 148 567 soles (US$ 44 830) para un paciente con 40 días de estancia. Fueron principales determinantes del costo de la atención la estancia hospitalaria y el número de ingresos al establecimiento. Se identificó que los "clúster" que tuvieron un costo mayor, fueron pacientes con edad de 70 y 72 años como mediana, con altos número de días de estancia y con alguna cirugía de alta complejidad. Conclusión. Los patrones de costos de la atención de la EIC estuvieron asociados a la estancia y los reingresos al establecimiento de salud. Los "clústers" con mayor costo estuvieron relacionados a la edad y complejidad de la cirugía.

ABSTRACT Introduction. Ischemic heart disease (IHD) is currently a public health problem in Peru, and its treatment tends to be very expensive for the health system. Goal. Establish the patterns of care costs of the EIC in the National Cardiovascular Institute (INCOR) of the Social Security in Health of Peru (EsSalud). Methods. The databases of care, surgeries, discharges and gross value of INCOR production of the population diagnosed and treated with IHD in 2019 (879 patients) were used. Costs of care were estimated using activity-based costing; an econometric model was used to establish the determinants of costs, and with the Euclidean distance method, "clusters" with similar characteristics were formed to establish cost patterns. Results. The highest cost of EIC care was 148 567 soles (US$ 44 830) for a patient with a 40-day stay. The main determinants of the cost of care were the hospital stay and the number of admissions to the establishment. It was identified that the "clusters" that had a higher cost were patients with a median age of 70 and 72 years, with a high number of days of stay and with some highly complex surgery. Conclusion. Cost patterns for IHD care were associated with length of stay and readmissions to the health facility. The "clusters" with the highest cost were related to age and complexity of the surgery.

Development of a 76k Alpaca (Vicugna pacos) Single Nucleotide Polymorphisms (SNPs) Microarray.

Small farm producers' sustenance depends on their alpaca herds and the production of fiber. Genetic improvement of fiber characteristics would increase their economic benefits and quality of life. The incorporation of molecular marker technology could overcome current limitations for the implementation of genetic improvement programs. Hence, the aim of this project was the generation of an alpaca single nucleotide polymorphism (SNP) microarray. A sample of 150 Huacaya alpacas from four farms, two each in Puno and Cerro de Pasco were used for SNP discovery by genotyping by sequencing (GBS). Reduced representation libraries, two per animal, were produced after DNA digestion with ApeK1 and double digestion with Pst1-Msp1. Ten alpaca genomes, sequenced at depths between 12× to 30×, and the VicPac3.1 reference genome were used for read alignments. Bioinformatics analysis discovered 76,508 SNPs included in the microarray. Candidate genes SNPs (302) for fiber quality and color are also included. The microarray SNPs cover 90.5% of the genome length with a density of about 39 ± 2.51 SNPs/Mb of DNA at an average interval of 26.45 ± 18.57 kbp. The performance was evaluated by genotyping 30 family trios and comparing them to their pedigrees, as well as comparing microarray to GBS genotypes. Concordance values of 0.93 and 0.94 for ApeK1 and Pst1-Msp1 generated SNPs were observed. Similarly, 290 fiber quality and color candidate gene SNPs were validated. Availability of this microarray will facilitate genome-wide association studies, marker-assisted selection and, in time, genomic selection.

Cytogenetic Mapping of 35 New Markers in the Alpaca (Vicugna pacos).

Alpaca is a camelid species of broad economic, biological and biomedical interest, and an essential part of the cultural and historical heritage of Peru. Recently, efforts have been made to improve knowledge of the alpaca genome, and its genetics and cytogenetics, to develop molecular tools for selection and breeding. Here, we report cytogenetic mapping of 35 new markers to 19 alpaca autosomes and the X chromosome. Twenty-eight markers represent alpaca SNPs, of which 17 are located inside or near protein-coding genes, two are in ncRNA genes and nine are intergenic. The remaining seven markers correspond to candidate genes for fiber characteristics (BMP4, COL1A2, GLI1, SFRP4), coat color (TYR) and development (CHD7, PAX7). The results take the tally of cytogenetically mapped markers in alpaca to 281, covering all 36 autosomes and the sex chromosomes. The new map assignments overall agree with human-camelid conserved synteny data, except for mapping BMP4 to VPA3, suggesting a hitherto unknown homology with HSA14. The findings validate, refine and correct the current alpaca assembly VicPac3.1 by anchoring unassigned sequence scaffolds, and ordering and orienting assigned scaffolds. The study contributes to the improvement in the alpaca reference genome and advances camelid molecular cytogenetics.

Evaluation of SNP Genotyping in Alpacas Using the Bovine HD Genotyping Beadchip.

Alpacas are one of four South American Camelid species living in the highlands of the Andes. Production of alpaca fiber contributes to the economy of the region and the livelihood of many rural families. Fiber quantity and quality are important and in need of a modern breeding program based on genomic selection to accelerate genetic gain. To achieve this is necessary to discover enough molecular markers, single nucleotide polymorphisms (SNPs) in particular, to provide genome coverage and facilitate genome wide association studies to fiber production characteristics. The aim of this study was to discover alpaca SNPs by genotyping forty alpaca DNA samples using the BovineHD Genotyping Beadchip. Data analysis was performed with GenomeStudio (Illumina) software. Because different filters and thresholds are reported in the literature we investigated the effects of no-call threshold (≥0.05, ≥0.15, and ≥0.25) and call frequency (≥0.9 and =1.0) in identifying positive SNPs. Average GC Scores, calculated as the average of the 10% and 50% GenCall scores for each SNP (≥0.70) and the GenTrain score ≥ 0.25 parameters were applied to all comparisons. SNPs with minor allele frequency (MAF) ≥ 0.05 or ≥ 0.01 were retained. Since detection of SNPs is based on the stable binding of oligonucleotide probes to the target DNA immediately adjacent to the variant nucleotide, all positive SNP flanking sequences showing perfect alignments between the bovine and alpaca genomes for the first 21 or 26 nucleotides flanking the variant nucleotide at either side were selected. Only SNPs localized in one scaffold were assumed unique. Unique SNPs identified in both reference genomes were kept and mapped on the Vicugna_pacos 2.0.2 genome. The effects of the no-call threshold ≥ 0.25, call frequency = 1 and average GC ≥ 0.7 were meaningful and identified 6756 SNPs of which 400 were unique and polymorphic (MAF ≥ 0.01). Assignment to alpaca chromosomes was possible for 292 SNPs. Likewise, 209 SNPs were localized in 202 alpaca gene loci and 29 of these share the same loci with the dromedary. Interestingly, 69 of 400 alpaca SNPs have 100% similarity with dromedary.