Parallel evolution or purifying selection, not introgression, explains similarity in the pyrethroid detoxification linked GSTE4 of Anopheles gambiae and An. arabiensis

Insecticide resistance is a major impediment to the control of vectors and pests of public health importance and is a strongly selected trait capable of rapid spread, sometimes even between closely-related species. Elucidating the mechanisms generating insecticide resistance in mosquito vectors of disease, and understanding the spread of resistance within and between populations and species are vital for the development of robust resistance management strategies. Here we studied the mechanisms of resistance in two sympatric members of the Anopheles gambiae species complex – the major vector of malaria in sub-Saharan Africa – in order to understand how resistance has developed and spread in eastern Uganda, a region with some of the highest levels of malaria. In eastern Uganda, where the mosquitoes Anopheles arabiensis and An. gambiae can be found sympatrically, low levels of hybrids (0.4%) occur, offering a route for introgression of adaptively important variants between species. In independent microarray studies of insecticide resistance, Gste4, an insect-specific glutathione S-transferase, was among the most significantly up-regulated genes in both species. To test the hypothesis of interspecific introgression, we sequenced 2.3kbp encompassing Gste4. Whilst this detailed sequencing ruled out introgression, we detected strong positive selection acting on Gste4. However, these sequences, followed by haplotype-specific qPCR, showed that the apparent up-regulation in An. arabiensis is a result of allelic variation across the microarray probe binding sites which artefactually elevates the gene expression signal. Thus, facevalue acceptance of microarray data can be misleading and it is advisable to conduct a more detailed investigation of the causes and nature of such signal. The identification of positive selection acting on this locus led us to functionally express and characterise allelic variants of GSTE4. Although the in vitro data do not support a direct role for GSTE4 in metabolism, they do support a role for this enzyme in insecticide sequestration. Thus, the demonstration of a role for an up-regulated gene in metabolic resistance to insecticides should not be limited to simply whether it can metabolise insecticide; such a strict criterion would argue against the involvement of GSTE4 despite the weight of evidence to the contrary

Development of ribozyme technology for gene down-regulation in farm animal species

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Effect of postmortem storage on shear force value and calpain/calpastatin activity in longissimus dorsi muscle of rusa deer

The objective of this study was to determine the effects of aging period on shear force values and activities of calpain/calpastatin enzymes of the longissimus dorsi (LD) muscle from rusa deer (Cervus timorensis). The shear force values were measured with instron materials testing machine. Results showed that postmortem storage influenced meat tenderness with a highly significant reduction of shear force value from 9.01±0.83 kg/cm2 at day 1 to 4.34±0.10 kg/cm2 at day 21 (P0.05). Shear force values were significant correlated with higher levels of μ-calpain (r=0.915) and m-calpain (r=0.758), respectively. However, the values were not significant related to the calpastatin activity (r=0.462). Therefore, this study confirmed that in the case of rusa deer, μ-calpain is a key factor controlling postmortem meat tenderness compared to m-calpain and calpastatin. The results suggested that storage of the rusa deer meat for 7 days is enough to achieve aging of the LD muscle, which may help to reduce the cost of meat production

Effect of postmortem storage on shear force value and calpain/calpastatin activity in longissimus dorsi muscle of rusa deer (cervus timorensis)

The objective of this study was to determine the effects of aging period on shear force values and activities of calpain/calpastatin enzymes of the longissimus dorsi (LD) muscle from rusa deer (Cervus timorensis). The shear force values were measured with instron materials testing machine. Results showed that postmortem storage influenced meat tenderness with a highly significant reduction of shear force value from 9.01±0.83 kg/cm2 at day 1 to 4.34±0.10 kg/cm2 at day 21 (P0.05). Shear force values were significant correlated with higher levels of μ-calpain (r=0.915) and m-calpain (r=0.758), respectively. However, the values were not significant related to the calpastatin activity (r=0.462). Therefore, this study confirmed that in the case of rusa deer, μ-calpain is a key factor controlling postmortem meat tenderness compared to m-calpain and calpastatin. The results suggested that storage of the rusa deer meat for 7 days is enough to achieve aging of the LD muscle, which may help to reduce the cost of meat production

Genetic Divergence of Thai Indigenous Pigs from Three Distinct Geographic Regions Revealed by Microsatellite Marker Analysis

Thai indigenous pigs (TIPs) are important genetic resources. Crosses with exotic pig breeds and wild boars may cause genetic losses. To date, the physical characteristics of TIPs have been inconsistent. The classification of TIPs by genetic information is needed to pursue an appropriate conservation program. In this study, the genetic diversity, cluster analysis, and phylogenetic relationship of TIPs were investigated using twenty-nine pig microsatellite markers. Blood samples were collected from TIPs from three regions of Thailand: north (NT, n = 118), northeast (NE, n = 61), and south (ST, n = 75). The mean total number of distinct alleles and the effective number of alleles per locus were 11.851 and 5.497, respectively. The mean observed heterozygosity (Ho) and mean expected heterozygosity (He) were 0.562 and 0.837, respectively. The F values of the microsatellite loci were positive under Hardy–Weinberg Equilibrium at p K = 3) were proposed within the TIP populations. Pigs from the NT and NE regions were mixed in two clusters, while members of the ST region were clearly separated. The phylogenetic tree confirmed that the pigs from NT and NE were each divided into two subgroups, while the pigs from ST were clustered into one group. A microsatellite analysis revealed the high genetic diversity of the TIP populations and confirmed the genetic divergence of the TIPs from the European and Chinese breeds. A genetic admixture of the TIP with the local wild boars was detected