RESUMO
BACKGROUND: Expansion of genomic resources for the Pacific white shrimp (Litopenaeus vannamei), such as the construction of dense genetic linkage maps, is crucial for the application of genomic tools in order to improve economically relevant traits. Sexual dimorphism exists in Pacific white shrimp, and the mapping of the sex-determination region in this species may help in future reproductive applications. We have constructed male, female, and sex-averaged high-density genetic maps using a 50 K single-nucleotide polymorphism (SNP) array, followed by a genome-wide association study (GWAS) to identify genomic regions associated with sex in white shrimp. RESULTS: The genetic map yielded 15,256 SNPs assigned to 44 linkage groups (LG). The lengths of the male, female, and sex-averaged maps were 5,741.36, 5,461.20 and 5,525.26 cM, respectively. LG18 was found to be the largest for both sexes, whereas LG44 was the shortest for males and LG31 for females. A sex-determining region was found in LG31 with 21 statistically significant SNPs. The most important SNP was previously identified as a sex-linked marker and was able to identify 99% of the males and 88% of the females. Although other significant markers had a lower ability to determine sex, putative genes were intercepted or close to them. The oplophorus-luciferin 2-monooxygenase, serine/arginine repetitive matrix protein and spermine oxidase genes were identified as candidates with possible participation in important processes of sexual differentiation in shrimp. CONCLUSIONS: Our results provide novel genomic resources for shrimp, including a high-density linkage map and new insights into the sex-determining region in L. vannamei, which may be usefulfor future genetics and reproduction applications.
Assuntos
Mapeamento Cromossômico , Penaeidae , Polimorfismo de Nucleotídeo Único , Processos de Determinação Sexual , Animais , Penaeidae/genética , Feminino , Masculino , Processos de Determinação Sexual/genética , Ligação Genética , Estudo de Associação Genômica AmplaRESUMO
Genome-wide association studies (GWAS) allow the identification of associations between genetic variants and important phenotypes in domestic animals, including disease-resistance traits. Whole Genome Sequencing (WGS) data can help increase the resolution and statistical power of association mapping. Here, we conduced GWAS to asses he facultative intracellular bacterium Piscirickettsia salmonis, which affects farmed rainbow trout, Oncorhynchus mykiss, in Chile using imputed genotypes at the sequence level and searched for candidate genes located in genomic regions associated with the trait. A total of 2130 rainbow trout were intraperitoneally challenged with P. salmonis under controlled conditions and genotyped using a 57K single nucleotide polymorphism (SNP) panel. Genotype imputation was performed in all the genotyped animals using WGS data from 102 individuals. A total of 488,979 imputed WGS variants were available in the 2130 individuals after quality control. GWAS revealed genome-wide significant quantitative trait loci (QTL) in Omy02, Omy03, Omy25, Omy26 and Omy27 for time to death and in Omy26 for binary survival. Twenty-four (24) candidate genes associated with P. salmonis resistance were identified, which were mainly related to phagocytosis, innate immune response, inflammation, oxidative response, lipid metabolism and apoptotic process. Our results provide further knowledge on the genetic variants and genes associated with resistance to intracellular bacterial infection in rainbow trout.
Assuntos
Estudo de Associação Genômica Ampla , Oncorhynchus mykiss , Animais , Masculino , Oncorhynchus mykiss/genética , Genótipo , Resistência à Doença/genéticaRESUMO
Sea lice (Caligus rogercresseyi) is an ectoparasite which causes major production losses in the salmon aquaculture industry worldwide. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two of the most susceptible salmonid species to sea lice infestation. The objectives of this study were to: (1) identify genomic regions associated with resistance to Caligus rogercresseyi in Atlantic salmon and rainbow trout by performing single-step Genome-Wide Association studies (ssGWAS), and (2) identify candidate genes related to trait variation based on exploring orthologous genes within the associated regions across species. A total of 2626 Atlantic salmon and 2643 rainbow trout were challenged and genotyped with 50 K and 57 K SNP panels, respectively. We ran two independent ssGWAS for sea lice resistance on each species and identified 7 and 13 regions explaining more than 1% of the genetic variance for the trait, with the most important regions explaining 3% and 2.7% for Atlantic salmon and rainbow trout, respectively. We identified genes associated with immune response, cytoskeleton function, and cell migration when focusing on important genomic regions for each species. Moreover, we found 15 common orthogroups which were present in more than one associated genomic region, within- or between-species; however, only one orthogroup showed a clear potential biological relevance in the response against sea lice. For instance, dual-specificity protein phosphatase 10-like (dusp10) and dual-specificity protein phosphatase 8 (dusp8) were found in genomic regions associated with lice density in Atlantic salmon and rainbow trout, respectively. Dusp10 and dusp8 are modulators of the MAPK pathway and might be involved in the differences of the inflammation response between lice resistant and susceptible fish from both species. Our results provide further knowledge on candidate genes related to sea lice resistance and may help establish better control for sea lice in fish populations.
Assuntos
Oncorhynchus mykiss/genética , Oncorhynchus mykiss/parasitologia , Ftirápteros/patogenicidade , Salmão/genética , Salmão/parasitologia , Animais , Aquicultura/métodos , Suscetibilidade a Doenças/microbiologia , Doenças dos Peixes/genética , Doenças dos Peixes/parasitologia , Estudo de Associação Genômica Ampla/métodos , Genômica/métodos , Genótipo , Imunidade/genética , Infestações por Piolhos/genética , Infestações por Piolhos/microbiologia , Fenótipo , Salmo salar/genética , Salmo salar/parasitologiaRESUMO
Data obtained at a central laboratory for emerging, re-emerging, and other infectious diseases in Mexico from 1995-2000 are presented. An outstanding increase of DEN-3 circulation was identified. Aedes aegypti, the dengue vector, is widely distributed. Leptospirosis has become the most important differential diagnosis for dengue. Identification of rabies virus variants allowed cataloging of new transmitters of rabies. Rotavirus showed a clear seasonal distribution, while different proportions of pathogenic classes of Escherichia coli under endemic and outbreak conditions were seen. Serotypes of several bacteria are reported as well as the sources of isolation and frequency of Shigella, Salmonella, and Vibrio cholerae. Rise and disappearance of cholera could be followed along the past decade. Influenza strains were identified, as were several pathogens causing sexually transmitted infections. Laboratory support was important for surveillance after Hurricane Mitch. Multidrug-resistant strains of Mycobacterium tuberculosis are emerging and primary resistance is very high. It is now mandatory to search for antibodies to Trypanosoma cruzi in blood banks. Triatoma barberi, a peridomestic bug, is the main vector of Chagas disease. Localized cutaneous leishmaniosis increased in regions having a guerrilla element in Chiapas. Modern immunodiagnostic techniques are used for control studies of cysticercosis and similar techniques were recently standardized for Trichinella spiralis detection. Low iodine values in children's urine were found in several Mexican states; therefore, use of iodized salt should be encouraged.
Assuntos
Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/epidemiologia , Inquéritos Epidemiológicos , Animais , Surtos de Doenças , Humanos , México/epidemiologia , Saúde Pública/métodos , Testes SorológicosRESUMO
Se describen los métodos y las técnicas utilizadas en el diagnóstico de la parálisis flácida aguda y de las enfermedades febriles exantemática. Contenido: A) DIAGNOSTICO DE LABORATORIO DE PARALISIS FLACIDA AGUDA: 1) Introducción. 2) Tratamiento de muestras para su clarificación. 3) Cultivo y mantenimiento de estirpes celulares. 4) Aislamiento de poliovirus y enterovirus en estirpes celulares. 5) Identificación y titulación. 6) Equipo, material y reactivos. 7) Pruebas moleculares. B) DIAGNOSTICO DE LABORATORIO DE ENFERMEDAD FEBRIL EXANTEMATICA: 1) Introducción. 2) Sarampión: diagnóstico, identificación y aislamiento del virus, inmunofluorescencia, determinación de anticuerpos séricos específicos. 3) Rubéola: diagnóstico, identificación y aislamiento del virus, inmunofluorescencia, determinación de anticuerpos séricos específicos. 4) Equipo, material y reactivos. 5) Vigilancia epidemiológica de las enfermedades febriles exantemáticas. Formato de envío de muestras