University of Los Andes

About: University of Los Andes is a education organization based out in Bogotá, Colombia. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 17616 authors who have published 25555 publications receiving 413463 citations.

Enolase as a plasminogen binding protein in Leishmania mexicana

Abstract: Enolase is a glycolytic and gluconeogenic enzyme also found on the surface of several eukaryotic and prokaryotic cells where it acts as plasminogen binding protein. Leishmania mexicana, one of the causative agents of Leishmaniasis, binds plasminogen and, in this parasite, enolase has been previously found associated with the external face of the plasma membrane. In this work, we show that the purified recombinant enolase has plasminogen binding activity indicating that, at the surface of the parasite, the protein may function as one of the plasminogen receptors. An internal motif (249)AYDAERKMY(257), similar to the nine amino-acid internal plasminogen-binding motif in Streptococcus pneumoniae enolase, is responsible for plasminogen interaction with the parasite enolase. Anti-enolase antibodies inhibited up to 60% of plasminogen binding on live parasites indicating that enolase act as a plasminogen receptor on the parasite. The fact that enolase acts as a possible plasminogen receptor in vivo makes this protein a promising target for therapy.

Ecological speciation along an elevational gradient in a tropical passerine bird

Abstract: Local adaptation of populations along elevational gradients is well known, but conclusive evidence that such divergence has resulted in the origin of distinct species in parapatry remains lacking. We integrated morphological, vocal, genetic and behavioural data to test predictions pertaining to the hypothesis of parapatric ecological speciation associated with elevation in populations of a tropical montane songbird, the Grey-breasted Wood-wren (Henicorhina leucophrys: Troglodytidae), from the Sierra Nevada de Santa Marta, Colombia. We confirmed that two distinct populations exist along the elevational gradient. Phylogenetic analyses tentatively indicate that the two populations are not sister taxa, suggesting they did not differentiate from a single ancestor along the gradient, but rather resulted from separate colonization events. The populations showed marked divergence in morphometrics, vocalizations and genetic variation in mitochondrial and nuclear loci, and little to no evidence of hybridization. Individuals of both populations responded more strongly to their own local songs than to songs from another elevation. Although the two forms do not appear to have differentiated locally in parapatry, morphological and vocal divergence along the elevational gradient is consistent with adaptation, suggesting a possible link between adaptive evolution in morphology and songs and the origin of reproductive isolation via a behavioural barrier to gene flow. The adaptive value of phenotypic differences between populations requires additional study.