RESUMO
Various interspersed repeated sequences and elements (IRSs) can be utilized to generate PCR-based multilocus fingerprint profiles by amplifying the interelement segments, using primers matching the elements themselves. We assessed the utility of inter-IRS fingerprinting in phylogenetic comparisons among six artiodactyl species using several primers derived from two abundant genomic components: the Bov-tA short interspersed nuclear elements (SINEs) and simple sequence repeats or microsatellites (SSRs). Character- and distance-based analyses of the fingerprint data produced trees conforming to the established phylogenetic relationships of species. The strength of phylogenetic signal from different primers varied; combining data from different experiments resulted in robust trees. Within the Cervidae, the hierarchical relationship [(Odocoileus, Rangifer) Alces] was strongly supported. Both methods appear useful tools for systematic studies at time scales <30 Myr. To elucidate the material basis of inter-SINE fingerprints, we obtained the first sequences of the 'bovid' Bov-tA element also from two cervids (reindeer and white-tailed deer) and analysed their relationship to a number of paralogous bovid elements. The differences among sequences, both intra- and interspecific, were relatively high (mean 18.5%); the sequences showed no clear clustering with the species from which they had been isolated. Most individual elements probably date back to the cervid-bovid ancestor >25 Myr ago, which is in line with the observed fingerprint distributions.
Assuntos
Artiodáctilos/genética , Impressões Digitais de DNA/métodos , Filogenia , Elementos Nucleotídeos Curtos e Dispersos/genética , Animais , Artiodáctilos/fisiologia , Sequência de Bases , Bovinos , Evolução Molecular , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , RNA de Transferência/genética , Ovinos/genética , Suínos/genéticaRESUMO
The applicability of single strand conformation polymorphism (SSCP) analysis for major histocompatibility complex (MHC) genotyping in sheep was studied. A panel of Ovar-DRB1 exon 2 'allele fingerprints' was defined. The panel could accelerate DRB1 genotyping of new breeds when already existing sequences are used as references in SSCP analysis. In this study, seven new exon 2 sequences and 19 different alleles in total were detected from 31 animals of Finnish and Russian sheep breeds. Ovar-DRB1*0201 was detected in all the six grey Finnsheep animals included in this study, suggesting reduced MHC diversity within these animals.
Assuntos
Antígenos de Histocompatibilidade/genética , Complexo Principal de Histocompatibilidade/genética , Polimorfismo Conformacional de Fita Simples , Ovinos/genética , Alelos , Animais , Impressões Digitais de DNA/veterinária , Éxons , Variação Genética , GenótipoRESUMO
A bovine RAPD profile, generated by a 10-mer primer, was analysed by sequencing the major fragments. Three of four different fragments showed homologies to previously characterized mammalian sequences. One was 61-66% identical to LINE sequences and another was 78.5% identical to a human chromosome 2 sequence tagged site. The third fragment was 93.1% identical to the human type 2 inositol 1,4,5-trisphosphate receptor gene. This fragment had counterparts in white-tailed deer and reindeer; fragments of slightly different size in these species showed high sequence similarity and the size differences were due to varying numbers of dinucleotide microsatellite repeats inside the fragment.
Assuntos
Artiodáctilos/genética , DNA/genética , Animais , Sequência de Bases , Canais de Cálcio/genética , Bovinos , Cromossomos Humanos Par 2/genética , Primers do DNA/genética , Cervos/genética , Feminino , Humanos , Receptores de Inositol 1,4,5-Trifosfato , Masculino , Dados de Sequência Molecular , Linhagem , Técnica de Amplificação ao Acaso de DNA Polimórfico , Receptores Citoplasmáticos e Nucleares/genética , Rena/genética , Homologia de Sequência do Ácido Nucleico , Sitios de Sequências Rotuladas , Especificidade da EspécieRESUMO
Scots pine (Pinus sylvestris) genomic libraries were constructed and screened with oligonucleotides probes (GT)10, (CT)10, and (AT)10. Eight microsatellites were identified from 6000 clones screened. The longest microsatellite stretch found, (CT)9(N)21(AT)24, was amplified from bud and single pollen grain samples. In order to clarify the complex amplification pattern revealed, two PCR products were sequenced. The size differences were caused both by varying repeat numbers of the microsatellite stretches and by differences in other parts of the amplified sequence. This kind of complex molecular basis of microsatellite amplification within a species has been previously reported. Microsatellite sequences were used as PCR primers to detect polymorphisms and to estimate the abundance of microsatellites.