11 research outputs found
Clusters of Nucleotide Substitutions and Insertion/Deletion Mutations Are Associated with Repeat Sequences
The authors propose that short repeat sequences may play an important role in causing the pervasive clustering of mutations across diverse genomes from prokaryotes to humans
In polymorphic genomic regions indels cluster with nucleotide polymorphism: Quantum Genomics
Previously, we have described polymorphic frozen blocks (PFBs) within the Major Histocompatibility Complex (MHC) as regions of several hundred kilobases characterised by high nucleotide diversity, little or no recombination, duplicated segments, disease susceptibility, and human endogenous retroviruses. The nucleotide diversity profile within these PFBs shows peaks and troughs outside of the Class I genes, reflecting other important genes (or sequences) in the region. Here we show that indel density is also clustered with similar peaks and troughs. In fact, SNPs and indels are co-located within PFBs
The Association Between HLA-A Alleles and an Alu Dimorphism Near HLA-G
The AluYb8 sequences are a subfamily of short interspersed Alu retroelements that have been amplified within the human genome during recent evolutionary time and are useful polymorphic markers for studies on the origin of human populations. We have identified a new member of the Yb8 subfamily, AluyHG, located between the HLA-H and -G genes and 88-kb telomeric of the highly polymorphic HLA-A gene within the alpha block of the major histocompatibility complex (MHC). The AluyHG element was characterised with a view to examining the association between AluyHG and HLA-A polymorphism and reconstructing the history of the MHC alpha block. A specific primer pair was designed for a simple PCR assay to detect the absence or presence (dimorphism) of the AluyHG element within the DNA samples prepared from a panel of 46 homozygous cell-lines containing complete or recombinant ancestral haplotypes (AH) of diverse ethnic origin and 92 Caucasoid and Asian subjects on which HLA-A typing was available. The AluyHG insertion was most strongly associated with HLA-A2 and, to a lesser degree with HLA-A1, -A3, -A11, and A-19. The gene frequency of the AluyHG insertion for 146 Caucasians and 94 Chinese-Han was 0.30 and 0.32 and there was no significant difference between the observed and expected frequencies. The results of the association studies and the phylogenetic analysis of HLA-A alleles suggest that the AluyHG sequence was integrated within the progenitor of HLA-A2, but has been transferred by recombination to other human ancestral populations. In this regard, the dimorphic AluyHG element is an important diagnostic marker for HLA association studies and could help in elucidating the evolution and functions of the MHC alpha block and polymorphism within and between ancestral haplotypes
Genomic analysis reveals a duplication of eight rather than seven short consensus repeats in primate CR1 and CR1L: evidence for an additional set shared between CR1 and CR2
Genesis of ancestral haplotypes: RNA modifications and reverse transcription–mediated polymorphisms
Genome Evolution in Outcrossing vs. Selfing vs. Asexual Species
International audienceA major current molecular evolution challenge is to link comparative genomic patterns to species' biology and ecology. Breeding systems are pivotal because they affect many population genetic processes and thus genome evolution. We review theoretical predictions and empirical evidence about molecular evolutionary processes under three distinct breeding systems-outcrossing, selfing, and asexuality. Breeding systems may have a profound impact on genome evolution, including molecular evolutionary rates, base composition, genomic conflict, and possibly genome size. We present and discuss the similarities and differences between the effects of selfing and clonality. In reverse, comparative and population genomic data and approaches help revisiting old questions on the long-term evolution of breeding systems