RESUMEN
In this study, we report an approach to characterize individual BoLA haplotypes using cells from parthenogenetic bovine embryos derived from slaughterhouse ovaries. Eight of the 15 parthenogenetic embryos so obtained had not undergone meiotic recombination on the BoLA region and were suitable to describe BoLA haplotypes. Detailed analysis of the BoLA class IIa region identified seven different class IIa haplotypes, including six not previously described and two new alleles of BoLA-DQA and one BoLA-DQB. Our method provided reliable sources of homozygous DNA to describe BoLA haplotypes.
Asunto(s)
Bovinos/genética , Genes MHC Clase II , Haplotipos , Alelos , Animales , Embrión de Mamíferos , PartenogénesisRESUMEN
The major histocompatibility complex (MHC) in mammals codes for antigen-presenting proteins. For this reason, the MHC is of great importance for immune function and animal health. Previous studies revealed this gene-dense and polymorphic region in river buffalo to be on the short arm of chromosome 2, which is homologous to cattle chromosome 23. Using cattle-derived STS markers and a river buffalo radiation hybrid (RH) panel (BBURH5000 ), we generated a high-resolution RH map of the river buffalo MHC region. The buffalo MHC RH map (cR5000 ) was aligned with the cattle MHC RH map (cR12000 ) to compare gene order. The buffalo MHC had similar organization to the cattle MHC, with class II genes distributed in two segments, class IIa and class IIb. Class IIa was closely associated with the class I and class III regions, and class IIb was a separate cluster. A total of 53 markers were distributed into two linkage groups based on a two-point LOD score threshold of ≥8. The first linkage group included 32 markers from class IIa, class I and class III. The second linkage group included 21 markers from class IIb. Bacterial artificial chromosome clones for seven loci were mapped by fluorescence in situ hybridization on metaphase chromosomes using single- and double-color hybridizations. The order of cytogenetically mapped markers in the region corroborated the physical order of markers obtained from the RH map and served as anchor points to align and orient the linkage groups.
Asunto(s)
Búfalos/genética , Bovinos/genética , Cromosomas de los Mamíferos/genética , Orden Génico/genética , Complejo Mayor de Histocompatibilidad/genética , Animales , Búfalos/inmunología , Cartilla de ADN/genética , Ligamiento Genético , Marcadores Genéticos , Biblioteca Genómica , Genotipo , Hibridación Fluorescente in Situ/veterinaria , Masculino , Familia de MultigenesRESUMEN
River buffalo genome analyses have advanced significantly in the last decade, and the genome sequence of Bubalus bubalis will be available shortly. Nonetheless, large-insert DNA library resources such as bacterial artificial chromosomes (BAC) are still required for validation and accurate assembly of the genome sequence. We constructed a river buffalo BAC library containing 52,224 clones with an average insert size of 97 kb, representing 1.7 × coverage of the genome. This genomic resource for river buffalo will facilitate further studies in this economically important species allowing for instance, whole genome physical mapping and isolation of genes and gene clusters, contributing to the elucidation of gene organization and identification of regulatory elements.
Asunto(s)
Búfalos/genética , Cromosomas Artificiales Bacterianos/genética , Biblioteca de Genes , Biología Molecular/métodos , Ríos , Animales , Emparejamiento Base/genéticaRESUMEN
Seven genes were assigned by molecular cytogenetic methods to bovine chromosome 5. To accomplish this, specific primers were either publicly available or were designed from highly conserved regions of the publicly available mammalian gene sequences. The identity of the amplified segments was verified by sequencing and alignment with the published sequences. The optimized primers that amplified the desired bovine genes were used for screening a bovine bacterial artificial chromosome library. The positive clones were localized to a specific band of bovine chromosome 5 by fluorescence in situ hybridization. The genes HOXC4, SP1 and IGFBP6 were localized to band q21, COL2A1 was localized to bands q21-q23, IGF1 was localized to band q26, MB to band q31 and the gene CYP2D6 was localized to band q35. The cytogenetic assignment of SP1, IGFBP6, COL2A1, IGF1, MB and CYP2D6 is first reported here and the assignment of HOXC4 refines the previous assignment of this gene. The identification and localization of these genes further support the development of the human to bovine comparative map through characterizing the homologous segments conserved in the evolution of these species. This information will be useful for the future localization of genes that affect economically important traits in bovines
Asunto(s)
Humanos , Animales , Bovinos/genética , Mapeo Cromosómico/veterinaria , Carácter Cuantitativo Heredable , Análisis de Secuencia de ADN/métodos , Análisis de Secuencia de ADN/veterinaria , Cromosomas Artificiales Bacterianos/genética , Hibridación Fluorescente in Situ , Mapeo Cromosómico/métodos , Reacción en Cadena de la PolimerasaRESUMEN
A computer system has been set up at the Medical Research Council Laboratories, Kingston, Jamaica, to assist in patient management and statistical analysis of data collected from over 4000 patients with sickle-cell disease. The records are stored in a patient data-base which includes personal data, relative cross-referencing information, haematological and clinical observations and a directory of stored sera samples. The information is processed in three main stages: the collection and editing; storage and maintenace; and retrieval and usage. Computer programmes have also been written to show the attendance pattern of children in the "cohort" clinic, which assists in maintaining regular follow-up. The computer system has become an integral part of the work of the Unit and offers a flexible approach to research (AU)