Genome-wide association study suggests genetic candidate loci of insulin dysregulation in Finnhorses

Equine metabolic syndrome (EMS) is a common welfare problem in horses worldwide. It is characterized by insulin dysregulation (ID), predisposition to laminitis and often obesity. EMS is multifactorial by nature, with both the environment and genetics contributing to the phenotype. Environmental factors, such as feeding and exercise, can be controlled, thus forming the basis for treatment and prevention. Genetic factors, by contrast, are less well-known and not easily controllable. The aim of this study was to identify potential genetic loci influencing ID/EMS in Finnhorses. A single-breed (Finnhorse) case-control genome-wide association study (GWAS) of ID was conducted with controls that included age-appropriate non-ID horses. ID status was determined with an oral sugar test (OST) for fasted horses. Seventy-one Finnhorses participated (n = 34 ID, n = 37 control). DNA samples (hair roots) were genotyped for 65 157 single-nucleotide polymorphisms (SNPs) with the Illumina Equine SNP70 BeadChip, and these data were analysed for association and FST outliers with genomic tools. P-values that exceeded the suggestive threshold (P = 1.00 ×10-5) were found in SNP BIEC2_383954 (P = 3.45 ×10-6) in chromosome 17 and SNP BIEC2_312374 (P = 1.89 ×10-5) in chromosome 15. Hierarchical and Bayesian FST outlier tests also detected these SNPs. Potential candidate genes associated with the ID close to SNP BIEC2_383954, with functions in carbohydrate metabolism, were Arginine and Glutamate Rich 1 (ARGLU1) and Ephrin-B2 (EFNB2).

Exposure to persistent organic pollutants and sperm sex chromosome ratio in men from the Faroe Islands

People in the Arctic as well as fishermen on the polluted Swedish east coast are highly exposed to persistent organic pollutants (POPs). These compounds have been shown to affect the sperm Y:X chromosome ratio. In present study, the aim was to investigate whether polychlorinated biphenyl (PCB) congeners and 1,1,-dichloro-2,2,-bis(p-chlorophenyl)ethane (p,p'-DDE) influence sperm sex chromosome ratio in Faroese men, and whether these men differ regarding Y:X ratio compared to Greenland Inuit and Swedish fishermen. The study population (n=449) consisted of young men from the general population (n=276) as well as proven fertile men (n=173). The Y:X ratio was assessed by fluorescent in situ hybridization. Serum concentrations of POPs were measured using gas chromatography. Associations between POP concentrations and Y:X ratio were calculated using linear and non-linear regression models as well as trend analysis and pairwise comparison of exposure data categorized into quartiles. The selected POPs were associated with Y:X ratio in fertile Faroese men, but not in the total population; p,p'-DDE (95% CI for B=-0.005 to -0.001, p=0.005) and ΣPCB (95% CI for B=-0.005 to -0.001, p=0.012). Since p,p'-DDE and ΣPCB correlated significantly (r=0.927, p<0.001), the results involving the exposure variables can be regarded as a single finding. The Y:X ratio for the total Faroese population was 0.500±0.018, which was statistically significantly lower than in both Inuit and Swedish fishermen (0.512 for both). In conclusion, Faroese men presented with lower Y:X ratio than Greenland Inuit and Swedish fishermen. Although no direct health effects are expected due to the lower Faroese Y:X ratio, it could be indicative of adverse effects on the reproductive system.

Microsatellite markers show distinctiveness of released and wild grey partridges in Finland

The main aim of this study was to study whether the present game farm stocks used for releases to the wild in Finland are similar to wild populations in their genetic structure, and if not, whether the wild populations show any signs of hybridisation. A total of 301 feather samples and ten microsatellite loci were used. Samples were collected from France, Great Britain, Finland (wild and captive) and Greece. We estimated pairwise FST–values between study populations, examined population structure and identified possible first generation migrants. Pairwise FST–values indicated structuring among studied populations. Results indicate that the farm stock used for releases deviates from the wild populations. No signs of hybridisation between the released and native birds were detected.

Colonisation and diversification of the blue tits (Parus caeruleus teneriffae-group) in the Canary Islands

The blue tit (Parus caeruleus teneriffae group) is proposed to have colonised the Canary Islands from North Africa according to an east-to-west stepping stone model, and today, the species group is divided into four subspecies, differing in morphological, acoustic, and ecological characters. This colonisation hypothesis was tested and the population structure between and within the islands studied using mitochondrial DNA sequences of the non-coding and relatively fast evolving control region. Our results suggest that one of the central islands, Tenerife, was colonised first and the other islands from there. Three of the presently recognised four subspecies are monophyletic, exception being the subspecies teneriffae, which consists of two monophyletic groups, the one including birds of Tenerife and La Gomera and the other birds of Gran Canaria. The Gran Canarian birds are well differentiated from birds of the other islands and should be given a subspecies status. In addition, the teneriffae subspecies group is clearly distinct from the European caeruleus group, and therefore the blue tit assemblage should be divided into two species.

Genomic organization of the human COL3A1 and COL5A2 genes: COL5A2 has evolved differently than the other minor fibrillar collagen genes

We report here on the complete structure of the human COL3A1 and COL5A2 genes. Collagens III and V, together with collagens I, II and XI make up the group of fibrillar collagens, all of which share a similar structure and function; however, despite the similar size of the major triple-helical domain, the number of exons coding for the domain differs between the genes for the major fibrillar collagens characterized so far (I, II, and III) and the minor ones (V and XI). The main triple-helical domain being encoded by 49-50 exons, including the junction exons, in the COL5A1, COL11A1 and COL11A2 genes, but by 43-44 exons in the genes for the major fibrillar collagens. Characterization of the genomic structure of the COL3A1 gene confirmed its association with the major fibrillar collagen genes, but surprisingly, the genomic organization of the COL5A2 gene was found to be similar to that of the COL3A1 gene. We also confirmed that the two genes are located in tail-to-tail orientation with an intergenic distance of approximately 22 kb. Phylogenetic analysis suggested that they have evolved from a common ancestor gene. Analysis of the genomic sequences identified a novel single nucleotide polymorphism and a novel dinucleotide repeat. These polymorphisms should be useful for linkage analysis of the Ehlers-Danlos syndrome and related disorders.

Mitochondrial control region polymorphism reveal high amount of gene flow in Fennoscandian willow tits (Parus montanus borealis)

We studied the genetic variability and differentiation of two Fennoscandian willow tit (Parus montanus borealis) populations located ca. 1000 km apart in Finland and Sweden by using the control region sequences of the mitochondrial DNA. Individual variation in the control region was extensive since all the 13 Finnish and the 12 Swedish individuals had unique haplotypes and the mean pairwise genetic distance resulted in 0.0052 (range 0.0008-0.0109). In the minimum spanning network connecting the genotypes, the two populations were completely intermingled. The mismatch distribution of the combined data set was very close to expected distribution of an expanding population. This result was supported by a significantly negative Tajima's D value. The sequence data indicate that (1) the long-term effective population size of the breeding willow tits has been large (122,000 and 110,000 females for the Finnish and the Swedish populations, respectively); and that (2) the gene exchange between distant localities is/has been extensive. Dispersal area for the Finnish females was estimated to be about 19,000-30,000 km2 and for the Swedish, 22,000-28,000 km2. Thus, the whole Fennoscandian population can be regarded as one panmictic unit, without any subdivisions to local demes. The amount of gene flow is remarkable because the willow tit has been considered a highly sedentary species. Provided that adult birds are site-tenacious, the gene flow must occur through juvenile summer dispersal, or irruptive autumn invasions, or both.

Mutated human androgen receptor gene detected in a prostatic cancer patient is also activated by estradiol

Androgens are necessary for the development of prostatic cancer. The mechanisms by which the originally androgen-dependent prostatic cancer cells are relieved of the requirement to use androgen for their growth are largely unknown. The human prostatic cancer cell line LNCaP has been shown to contain a point mutation in the human androgen receptor gene (hAR), suggesting that changes in the hAR may contribute to the abnormal hormone response of prostatic cells. To search for point mutations in the hAR, we used single strand conformation polymorphism analysis and a polymerase chain reaction direct sequencing method to screen 23 prostatic cancer specimens from untreated patients, 6 prostatic cancer specimens from treated patients, and 11 benign prostatic hyperplasia specimens. One mutation was identified in DNA isolated from prostatic cancer tissue, and the mutation was also detected in the leukocyte DNA of the patient and his offspring. The mutation changed codon 726 in exon E from arginine to leucine and was a germ line mutation. The mutation we found in exon E of the hAR gene does not alter the ligand binding specificity of the AR, but the mutated receptor was activated by estradiol to a significantly greater extent than the wild-type receptor. The AR gene mutation described in this study might be one explanation for the altered biological activity of prostatic cancer.

Pharmacokinetics of different epidural sites of morphine administration

In order to determine the rate and degree of redistribution of morphine within the cerebrospinal fluid (CSF), and whether it was affected by the site of and volume of the injection, morphine was given to 23 elderly patients undergoing thoracotomy - in 10 ml saline in the lumbar epidural interspace (n = 5), in 10 ml saline in the thoracic epidural interspace (n = 5), in 2 ml saline in the thoracic interspace (n = 8) and in 10 ml saline in the lumbar epidural interspace (n = 5). The plasma concentration of morphine in all patients was comparable and was much lower than in the CSF. The CSF morphine concentration, measured as the area under the CSF concentration curve (AUC), the maximal CSF concentration (Cmax) and the time to reach maximal CSF concentration (tmax), varied between the four groups. The variation was related to the site of the injection; the AUC and Cmax were lower and tmax appeared later after thoracic than lumbar injection. Lumbar CSF morphine concentrations were further reduced by thoracic epidural injection of morphine in a small as compared to a large volume. The permeability of the dura to morphine was not influenced by the volume used. The results show that morphine is not homogeneously distributed within the CSF. The availability of morphine to CSF from the epidural space is not altered by the injection volume, but the drug remains more localized in CSF after epidural injection of morphine in a small volume.(ABSTRACT TRUNCATED AT 250 WORDS)