RESUMEN
Summary The purine nucleotides adenosine monophosphate (AMP) and guanosine monophosphate (GMP) are critical for energy metabolism, cell signalling and cell reproduction. Despite their essential function, little is known about the regulation and in vivo expression pattern of the genes involved in the de novo purine synthesis pathway. The complete coding region of the bovine phosphoribosylaminoimidazole carboxylase gene (PAICS), which catalyses steps 6 and 7 of the de novo purine biosynthesis pathway, as well as bovine genomic sequences of the six other genes in the pathway producing inosine monophosphate (IMP) and AMP [phosphoribosyl pyrophosphate amidotransferase (PPAT), phosphoribosylglycinamide formyltransferase (GART), phosphoribosylformylglycinamidine synthase (PFAS), adenylosuccinate lyase (ADSL), 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC) and adenylosuccinate synthase (ADSS)], were identified. The genes were mapped to segments of six different bovine chromosomes using a radiation hybrid (RH) cell panel. The gene PPAT, coding for the presumed rate-limiting enzyme of the purine de novo pathway was closely linked to PAICS on BTA6. These, and the other bovine locations i.e. GART at BTA1, PFAS at BTA19, ADSL at BTA5, ATIC at BTA2 and ADSS at BTA16, are in agreement with published comparative maps of cattle and man. PAICS and PPAT genes are known to be closely linked in human, rat and chicken. Previously, an expressed sequence fragment of PAICS (Bos taurus corpus luteum, BTCL9) was mapped to BTA13. By isolation and characterization of a BAC clone, we have now identified a PAICS processed pseudogene sequence (psiPAICS) on BTA13. Processed pseudogene sequences of PAICS and other genes of the purine biosynthesis pathway were identified in several mammalian species, indicating that the genes of this pathway have been susceptible to retrotransposition. The seven bovine genes are expressed at a higher level in testicular and ovary tissues compared with skeletal muscle.
Asunto(s)
Adenosina Monofosfato/biosíntesis , Bovinos/genética , Mapeo de Híbrido por Radiación , Adenosina Monofosfato/genética , Adenilosuccinato Liasa/genética , Adenilosuccinato Liasa/metabolismo , Adenilosuccinato Sintasa/genética , Adenilosuccinato Sintasa/metabolismo , Amidofosforribosiltransferasa/genética , Amidofosforribosiltransferasa/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Ligasas de Carbono-Nitrógeno con Glutamina como Donante de Amida-N/genética , Ligasas de Carbono-Nitrógeno con Glutamina como Donante de Amida-N/metabolismo , Carboxiliasas/genética , Carboxiliasas/metabolismo , Cartilla de ADN , Femenino , Gónadas/metabolismo , Transferasas de Hidroximetilo y Formilo/genética , Transferasas de Hidroximetilo y Formilo/metabolismo , Masculino , Datos de Secuencia Molecular , Músculo Esquelético/metabolismo , Nucleótido Desaminasas/genética , Nucleótido Desaminasas/metabolismo , Fosforribosilglicinamida-Formiltransferasa , Seudogenes/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
A representational difference analysis was performed to identify genes expressed in the corpus luteum of cattle. The corpus luteum is an ovarian structure that is essential for the establishment and maintenance of pregnancy. Knowledge of gene expression and function of corpus luteum will be important to improve fertility in humans and domestic animals. Housekeeping genes were removed from the corpus luteum representation (tester) using skeletal muscle as the subtracting agent (driver). A total of 80 clones of the final subtraction product were analysed by sequencing and 11 new bovine gene sequences were identified (pBTCL1-11). The sequences were mapped to segments of 10 different chromosomes using a somatic cell hybrid panel and a radiation hybrid panel. With one exception the locations are in agreement with published comparative maps of cattle and man. Expression in corpus luteum was verified by RT-PCR for all the 11 clones.
Asunto(s)
Bovinos/genética , Mapeo Cromosómico , Cuerpo Lúteo/fisiología , Expresión Génica , Animales , Secuencia de Bases , Southern Blotting , Cartilla de ADN , ADN Complementario/genética , Etiquetas de Secuencia Expresada , Femenino , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADNRESUMEN
In this study, we present a comprehensive 3,000-rad radiation hybrid (RH) map of bovine chromosome 7 (BTA7) with 108 markers including 54 genes or ESTs. For 52 of them, a human ortholog sequence was found either on HSA1 (one gene), HSA5 (31 genes) or HSA19 (19 genes and one non-annotated sequence) confirming previously described syntenies. Moreover, in order to refine boundaries of blocks of conserved synteny, nine new genes were mapped to the bovine genome on the basis of their localization on the human genome: six on BTA7 and originating from HSA1 (TRIM17), HSA5 (MAN2A1, LMNB1, SIAT8D and FLJ1159) and HSA19 (VAV1), and the three others (AP3B1, APC and CCNG1) on BTA10. The available draft of the human genome sequence allowed us to present a detailed picture of the distribution of conserved synteny segments between man and cattle. Finally, the INRA bovine BAC library was screened for most of the BTA7 markers considered in this study to provide anchors for the bovine physical map.