Juan Ignacio Serrano-Vela

Different evolutionary pathway of B*570101 and B*5801 (B17 group) alleles based in intron sequences.

AbstractTwo theories about MHC allele generation have been put forward: (1) point mutation diversification and/or (2) gene conversion events. A model supporting the existence of both of these mechanisms is shown in this paper; the possible evolution of the HLA-B*570101 and HLA-B*5801 alleles (which belong to the HLA-B17 serology group) is studied. The hypothesis favoured is that gene conversion events have originated these alleles, because intron sequences are also analysed. Evolution by point mutation should only be accepted if flanking introns have also been sequenced.

Mitochondrial DNA Phylogenetic Definition of a Group of 'Arid-Zone' Carduelini Finches

Birds included within the Carduelini tribe (genera Rhodopechys, Carpodacus and Leucosticte) apparently be- long to the same radiation according to molecular phylogenetic analyses. Our phylogenetic analyses based on nucleotide sequences of the cytochrome b gene (cyt-b) indicate that some of these birds (Rhodopechys mongolica, R. githaginea and Carpodacus nipalensis) do not cluster together with their respective phenetically defined allies. This new group of birds thrives in both hot and cold arid zones and are phenetically distinct, probably because of their adaptation to different ex- treme environments. Both maximum likelihood and Bayesian inference methods support the existence of this new evolu- tionary basal group among finches which might have originated about 14 million years ago.

Different Evolution of Inhibitory and Activating Killer Immunoglobulin Receptors (KIR) in Worldwide Human Populations

HLA class I molecules are ligands for natural killer cells’ inhibitory (KIR DL) and activating (KIR DS) receptors. KIR DL receptors have a greater avidity for HLA class I molecules than KIR DS receptors. Thus, there is a possibility that HLA molecules drive KIR receptor selection. We have used the percentage of individuals bearing the genes KIR 3DS1, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 2DL1, 2DL2, 2DL3, 2DL5 and 3DL1 in relatively well defined populations to test whether there is a different way of relating worldwide populations between KIR DS and KIR DL molecules. We h ave use d A RLEQUIN, D ISPAN and V ISTA computer p rograms t o c onstruct d endrograms a nd correspondence analyses showing the genetic relationships among different human world populations. Analyses based on KIR DS or KIR haplotype B ge nes show that populations are re lated according to geography, l ike a good a nthropological m arker (i .e.: HLA or Y chromosome systems). The results based on KIR DL or KIR haplotype A genes do not show such a correlation. Results are discussed taking into account the linkage of both HLA and KIR systems to microbial diseases and the possible evolutionary shaping of both HLA and KIR receptors repertoire by pathogens.

Human leukocyte antigen haplotypes and HFE mutations in Spanish hereditary hemochromatosis and sporadic porphyria cutanea tarda

Background and Aims:  It has been postulated that the HFE C282Y mutation (linked to human leukocyte antigen [HLA]‐A3‐B7 haplotype) is not only responsible for hereditary hemochromatosis; HLA class I alleles would also contribute to the disease pathogenesis. In addition, H63D mutation linked to HLA‐A29‐B44 would also be pathogenetic, particularly in the Mediterranean Basin and throughout the world. However, sporadic porphyria cutanea tarda (s‐PCT) has also been linked to these HFE mutations. In the present work, we have studied HFE mutations and HLA genes to test these hypotheses.

A novel allele, HLA-G*010114, with a non-coding DNA base change in exon 2.

The non-classical human leucocyte antigen (HLA) class I locus, HLA-G, shows a low protein polymorphism and a more varied DNA (eight proteins and 28 alleles). HLA-G DNA polymorphism accounts mainly for changes at third codon bases of the protein coding exons; this does not imply amino acid change in most cases. This relatively high HLA-G DNA polymorphism in comparison with their protein polymorphism suggests that evolutionary forces are acting upon HLA-G for invariance. This may be related to the immunotolerogenic function postulated for HLA-G.

Rhodopechys obsoleta (desert finch): a pale ancestor of greenfinches (Carduelis spp.) according to molecular phylogeny

The evolutionary history of three out of four birds traditionally classified into the genus Rhodopechys birds has been studied by comparing their mitochondrial cytochrome b DNA sequence with that of greenfinches and other genus Carduelis finches. The desert finch (Rhodopechys obsoleta) or a sister extinct species seems to have existed about 6 million years ago in Asian and perhaps African desert-like areas. This bird has no molecular relationship with other Rhodopechys birds and seems to have given rise to the greenfinches radiation, probably by allopatry of marginal or isolated groups; the latter would have evolved to green plumage colours and more simple song modulations (i.e., greenfinches). The possible role of assortative mating and the newly postulated acquired phenotypic characters in greenfinches speciation are discussed.

Rhodopechys obsoleta (desert finch): a pale ancestor of greenfinches (Carduelis

The evolutionary history of three out of four birds traditionally classified into the genus Rhodopechys birds has been studied by comparing their mitochondrial cytochrome b DNA sequence with that of greenfinches and other genus Carduelis finches. The desert finch (Rhodopechys obsoleta) or a sister extinct species seems to have existed about 6 million years ago in Asian and perhaps African desert-like areas. This bird has no molecular relationship with other Rhodopechys birds and seems to have given rise to the greenfinches radiation, probably by allopatry of marginal or isolated groups; the latter would have evolved to green plumage colours and more simple song modulations (i.e., greenfinches). The possible role of assortative mating and the newly postulated acquired phenotypic characters in greenfinches speciation are discussed.

What Might have been the Ancestor of New World Siskins?~!2008-08-04~!2008-10-29~!2008-12-05~!

Eurasian Carduelis spinus (siskin) has given rise to the C.pinus (pine siskin) North American radiation,which includes C.dominicensis, C.p. perplexus and C.atriceps . It is addressed the question why C.spinus is not thriving now in America.