Mercury (Hg) vapor can produce kidney injury, where the proximal tubule region of the nephron is the main target of the Hg-induced oxidative stress. Hg is eliminated from the body as a glutathione conjugate. Thus, single nucleotide polymorphisms (SNPs) in glutathione-related genes might modulate the negative impact of this metal on the kidneys. Glutathione-related SNPs were tested for association with levels of Hg and renal function biomarkers between occupationally exposed (n = 160) and non-exposed subjects (n = 121). SNPs were genotyped by TaqMan assays in genomic DNA samples. Total mercury concentration was measured in blood, urine and hair samples. Regression analyses were performed to estimate the effects of SNPs on quantitative traits. Alleles GCLM rs41303970-T and GSTP1 rs4147581-C were significantly overrepresented in the exposed compared with the non-exposed group (P < 0.01). We found significant associations for GCLM rs41303970-T with higher urinary clearance rate of Hg (β = 0.062, P = 0.047), whereas GCLC rs1555903-C was associated with lower levels of estimated glomerular filtration rate in the non-exposed group (eGFR, β = − 3.22, P = 0.008) and beta-2-microglobulin in the exposed group (β-2MCG, β = − 19.32, P = 0.02). A SNP-SNP interaction analysis showed significant epistasis between GSTA1 rs3957356-C and GSS rs3761144-G with higher urinary levels of Hg in the exposed (β = 0.13, P = 0.04) but not in the non-exposed group. Our results suggest that SNPs in glutathione-related genes could modulate the pathogenesis of Hg nephrotoxicity in our study population by modulating glutathione concentrations in individuals occupationally exposed to this heavy metal.

In artisanal and small-scale gold mining, occupational exposure to mercury (Hg) vapor is related to harmful effects on several organs, including the kidneys. We previously reported significantly increased levels of Hg in blood and urine despite normal kidney function in individuals from Colombia occupationally exposed to Hg compared to those non-exposed. We evaluated the contribution of four genetic variants in key genes encoding the transporters SLC (rs4149170 and rs4149182) and ABC (rs1202169 and rs1885301) in the pathogenesis of nephrotoxicity due to Hg exposure in these groups. Regression analysis was performed to determine the association between the blood- and urine-Hg concentration with SLC and ABC polymorphisms in 281 Colombian individuals (160 exposed and 121 non-exposed to Hg). We found an enrichment of ABCB1 rs1202169-T allele in the exposed group (P = 0.011; OR = 2.05; 95% CI = 1.18–3.58) compared with the non-exposure group. We also found that carriers of SLC22A8 rs4149182-G and ABCB1 rs1202169-T alleles had a higher urinary clearance rate of Hg than non-carriers (β = 0.13, P = 0.04), whereas carriers of SLC22A6 rs4149170-A and ABCB1 rs1202169-C alleles showed abnormal levels of estimated glomerular filtration rate (eGFR) (β= -84.96, P = 0.040) and beta-2-microglobulin (B2M) (β = 743.38, P &lt; 0.001). Our results suggest that ABCB1 rs1202169 and its interaction with SLC22A8 rs4149182 and SLC22A6 rs4149170 could mitigate Hg nephrotoxicity by controlling the renal proximal tubule cell accumulation of inorganic Hg. This will be useful to estimate the risk of kidney toxicity associated to Hg and the genetic selection to aid adaptation to Hg-rich environments.

To genetic characterize the nesting colony of L. olivacea in Palmeras beach-Gorgona National Natural Park- and to contribute to the implementation of strategies of conservation for the species, a fragment of the mitocondrial DNA control region (D-loop) was sequenced in 29 individuals for studying the genetic diversity and phylogenetic relationships in comparison with data published in GenBank. The analysis of the sequences revealed the presence of two haplotypes N (96.55%) and E (3.45%), according to the sequences reported for this species. The genetic (h) and nucleotide (π) diversity of the studied colony was h=0.069 and π =0.023%, these results corroborate that the Testudines presents a low genetic diversity. These values of diversity are low when they were compared with continental populations of L. olivacea of the South of Baja California (h=0.16 and π=0.06%), Eastern Pacific (h=0.60 and π =0.26%) and east of India (Sri Lanka with h=0.72 and π =2.07%; Orissa with h=0.27 and π=0.3%) in spite of different number of colonies. The analyses of phylogenetic inference, using the Neighbour- Joining method, confirm the cluster of the haplotypes in two geographical regions (eastern Pacific and east India). We conclude that the presence of the haplotype N corroborate the hypothesis of natal homing (adult females return to lay eggs in the general region where they were born) of L. olivacea in Palmeras beach, this information contribute in the definition of management units required for the implementation of conservation strategies for the species.

La infección causada por haemosporidios en colibríes no ha sido estudiada en zonas agroforestales o urbanas de la vertiente occidental de la Cordillera Oriental de los Andes en el departamento de Santander, pese a existir evidencia de esta en otros grupos de aves. Con el fin de detectar e identificar los parásitos causales de infecciones por haemosporidios, se tomaron muestras de sangre de la vena yugular de colibríes en seis localidades.  La presencia de infección se llevó a cabo por PCR y la identificación de los parásitos se hizo a partir de secuencias del gen mitocondrial Citocromo b (Cyt b).  Se obtuvieron 86 muestras de sangre de 20 especies de colibríes.  La prevalencia de infección en general fue del 43 % y en el 18 % de las muestras infectadas del colibrí Amazilia colirufa (Amazilia tzacatl) se identificaron secuencias de Haemoproteus archilochus correspondientes al linaje HUMHA4.  Se reporta por primera vez para Colombia la presencia de H. archilochus en A. tzacatl, por medio de técnicas de biología molecular. Este parásito podría estar implicado en la haemoproteosis de colibríes en el país.

Domestic pigeons have high polymorphism in plumage morphs and colours. The genes that affect colour and coat patterns can be used to estimate genetic profiles that allow us to deduce the structures of populations, establish whether they are in a population equilibrium and learn the genetic similarity among them. This article tested these population components and the existing relationships among cities in northern South America, Western Europe and Singapore (Southeast Asia) through the inventory of phenotypic frequencies and the estimation of allele frequencies for the Pattern, Grizzle, Background colour, Spread, Crest, Recessive white and Feathered feet loci. The Hardy–Weinberg equilibrium was evaluated based on the Pattern and Grizzle loci. The results showed a higher genetic diversity in populations from northern South America with respect to the one from Western Europe, although the differentiation among cities was low ( GST = 0.0759). Several populations were not in the Hardy–Weinberg equilibrium for the evaluated loci, and a significant correlation between genetic and geographic distances was not found. The relatively small home range of the pigeons and the dispersion carried out by humans are discussed as possible explanations for the current genetic profiles.