An Approach to Identify SNPs in the Gene Encoding Acetyl-CoA Acetyltransferase-2 (ACAT-2) and Their Proposed Role in Metabolic Processes in Pig

The novel liver protein acetyl-CoA acetyltransferase-2 (ACAT2) is involved in the beta-oxidation and lipid metabolism. Its comprehensive relative expression, in silico non-synonymous single nucleotide polymorphism (nsSNP) analysis, as well as its annotation in terms of metabolic process with another protein from the same family, namely, acetyl-CoA acyltransferase-2 (ACAA2) was performed in Sus scrofa. This investigation was conducted to understand the most important nsSNPs of ACAT2 in terms of their effects on metabolic activities and protein conformation. The two most deleterious mutations at residues 122 (I to V) and 281 (R to H) were found in ACAT2. Validation of expression of genes in the laboratory also supported the idea of differential expression of ACAT2 and ACAA2 conceived through the in silico analysis. Analysis of the relative expression of ACAT2 and ACAA2 in the liver tissue of Jeju native pig showed that the former expressed significantly higher (P<0.05). Overall, the computational prediction supported by wet laboratory analysis suggests that ACAT2 might contribute more to metabolic processes than ACAA2 in swine. Further associations of SNPs in ACAT2 with production traits might guide efforts to improve growth performance in Jeju native pigs.     

Multiple intravenous administrations of human umbilical cord blood cells benefit in a mouse model of ALS

Background

A promising therapeutic strategy for amyotrophic lateral sclerosis (ALS) is the use of cell-based therapies that can protect motor neurons and thereby retard disease progression. We recently showed that a single large dose (25×10⁶ cells) of mononuclear cells from human umbilical cord blood (MNC hUCB) administered intravenously to pre-symptomatic G93A SOD1 mice is optimal in delaying disease progression and increasing lifespan. However, this single high cell dose is impractical for clinical use. The aim of the present pre-clinical translation study was therefore to evaluate the effects of multiple low dose systemic injections of MNC hUCB cell into G93A SOD1 mice at different disease stages.

Methodology/Principal Findings

Mice received weekly intravenous injections of MNC hUCB or media. Symptomatic mice received 10⁶ or 2.5×10⁶ cells from 13 weeks of age. A third, pre-symptomatic, group received 10⁶ cells from 9 weeks of age. Control groups were media-injected G93A and mice carrying the normal hSOD1 gene. Motor function tests and various assays determined cell effects. Administered cell distribution, motor neuron counts, and glial cell densities were analyzed in mouse spinal cords. Results showed that mice receiving 10⁶ cells pre-symptomatically or 2.5×10⁶ cells symptomatically significantly delayed functional deterioration, increased lifespan and had higher motor neuron counts than media mice. Astrocytes and microglia were significantly reduced in all cell-treated groups.

Conclusions/Significance

These results demonstrate that multiple injections of MNC hUCB cells, even beginning at the symptomatic disease stage, could benefit disease outcomes by protecting motor neurons from inflammatory effectors. This multiple cell infusion approach may promote future clinical studies.     

Novel role for the innate immune receptor Toll-like receptor 4 (TLR4) in the regulation of the Wnt signaling pathway and photoreceptor apoptosis

Recent evidence has implicated innate immunity in regulating neuronal survival in the brain during stroke and other neurodegenerations. Photoreceptors are specialized light-detecting neurons in the retina that are essential for vision. In this study, we investigated the role of the innate immunity receptor TLR4 in photoreceptors. TLR4 activation by lipopolysaccharide (LPS) significantly reduced the survival of cultured mouse photoreceptors exposed to oxidative stress. With respect to mechanism, TLR4 suppressed Wnt signaling, decreased phosphorylation and activation of the Wnt receptor LRP6, and blocked the protective effect of the Wnt3a ligand. Paradoxically, TLR4 activation prior to oxidative injury protected photoreceptors, in a phenomenon known as preconditioning. Expression of TNFα and its receptors TNFR1 and TNFR2 decreased during preconditioning, and preconditioning was mimicked by TNFα antagonists, but was independent of Wnt signaling. Therefore, TLR4 is a novel regulator of photoreceptor survival that acts through the Wnt and TNFα pathways.     

QTL mapping of yield-associated traits in Brassica juncea: meta-analysis and epistatic interactions using two different crosses between east European and Indian gene pool lines

Genetic analysis of 12 yield-associated traits was undertaken by dissection of quantitative trait loci (QTL) through meta-analysis and epistatic interaction studies in Brassica juncea. A consensus (integrated) map in B. juncea was constructed using two maps. These were VH map, developed earlier in the laboratory by using a DH population from the cross between Varuna and Heera (Pradhan et al. in Theor Appl Genet 106:607–614, 2003; Ramchiary et al. in Theor Appl Genet. 115:807–817, 2007; Panjabi et al. in BMC Genomics 9:113, 2008), and the TD map, developed in the present study using a DH population of 100 lines from the cross between TM-4 and Donskaja-IV. The TD map was constructed with 911 markers consisting of 585 AFLP, 8 SSR and 318 IP markers covering a total genome length of 1,629.9?cM. The consensus map constructed by using the common markers between the two maps contained a total of 2,662 markers and covered a total genome length of 1,927.1?cM. Firstly, QTL analysis of 12 yield-associated traits was undertaken for the TD population based on three-environment phenotypic data. Secondly, the three-environment phenotypic data for the same 12 quantitative traits generated by Ramchiary et al. (2007) were re-analyzed for the QTL detection in the VH map. Comparative analysis identified both common and population-specific QTL. The study revealed the presence of QTL clusters on LG A7, A8 and A10 in both TD and VH maps. Meta-analyses resolved 187 QTL distributed over nine linkage groups of TD and VH maps into 20 meta-QTL. Maximum resolution was recorded for the LG A10 wherein all the 54 QTL were mapped to a single meta-QTL within a confidence interval of 3.0?cM. Digenic epistatic interactions of QTL in both TD and VH maps revealed substantial additive?×?additive interactions showing a higher frequency of Type 1 and Type 2 interactions than Type 3 interactions. Some of the loci interacted with more than one locus indicating the presence of higher order epistatic interactions. These findings provided some detailed insight into the genetic architecture of the yield-associated traits in B. juncea.     

A comparison of bird communities of two fragmented and two continuous southeast Asian rainforests

A large proportion of forest-dependent bird species have disappearedfrom Singapore, probably due to heavy forest loss that started in the 1800s. Thebird fauna seems to have relaxed (attained a lower and relatively stablediversity following habitat destruction) in Singapore. Using mist-netting, Icompared understory bird communities of two lowland rainforest fragments inSingapore (Nee Soon and MacRitchie) with two continuous forests in Sarawak(Malaysia) (Matang Wildlife Sanctuary and Gunung Gading National Park). Icompared community characteristics (e.g. rarity [<2 individuals/1000mist-netting hours]), population characteristics (e.g. sex ratio) and individualquality (e.g. prevalence of ectoparasites) among avifaunas of the forests. Onaverage, more bird species and individuals were caught in continuous foreststhan in fragments. There were more rare species in Gading. The proportion ofadults and the sex ratios did not differ among the forests. Ectoparasiteprevalence and intensity also did not differ among the forests. Proportionallymore individuals contained fault bars in MacRitchie. My study shows that aviancommunities in rainforest fragments are depauperate but show few signs ofenvironmental stress. Thus there may be long-term resilience in some forest birdspecies. However, it is essential to protect large tracts of tropical lowlandrainforest to preserve rare forest-dependent avifauna.     

The effect of human disturbance and flock composition on the flight distances of waterfowl species

Flocking bird species tolerate an approaching human up to a certain distance. We measured this distance, i.e., flight distance, to an approaching small boat for 11 waterfowl species. The flight distances correlated positively with flock size and species diversity (Shannon index H′) in species that showed relatively short flight distances when they were in a single-species flock. However, we did not observe such a correlation for single-species flocks that showed relatively long flight distances. Only pochards (Aythya ferina), a species with large individual variation in flight distances, showed a positive correlation between flight distance and flock size in both single- and multispecies flocks. Flight distance seemed to be affected by usage of the water area: flight distances tended to be longer for waterfowl species that use a water area for foraging than for those that use it primarily for resting. Thus, the behavior of actively foraging species may be more affected by human disturbances than that of resting species. Received: March 10, 2001 / Accepted: May 22, 2001     

Viral hijacking of G-protein-coupled-receptor signalling networks

Viruses use a surprising diversity of approaches to hijack G-protein-coupled receptors and harness their activated intracellular signalling pathways. All of these approaches ultimately function to ensure viral replicative success and often contribute to their pathogenesis. Indeed, a single virus might deploy a repertoire of these strategies to regulate key intracellular survival, proliferative and chemotactic pathways. Understanding the contribution of these biochemical routes to viral pathogenesis might facilitate the development of effective target-specific therapeutic strategies against viral diseases.     

A high-density linkage map in <Emphasis Type="Italic">Brassica juncea</Emphasis> (Indian mustard) using AFLP and RFLP markers

A high-density genetic linkage map of Brassica juncea (2n = 36) was constructed with 996 AFLP (amplified fragment length polymorphism) and 33 RFLP (restriction fragment length polymorphism) markers using a F1-derived doubled-haploid (DH) population of 123 individuals. This mapping population was developed by crossing a well-adapted, extensively grown Indian variety Varuna and a canola quality line Heera. The two lines are highly divergent and contain a number of contrasting qualitative and quantitative traits of high agronomic value. AFLPs were generated by the use of restriction enzymes EcoRI or PstI in combination with either MseI or TaqI. Using 91 primer pairs, a total of 1,576 parental polymorphic bands were detected of which 996 were used for mapping. In addition, 33 RFLP markers, developed from genomic clones of B. napus, were added to the map. The segregation of each marker and linkage analysis was performed using the program JoinMap version 2.0. The 1,029 mapped-markers were aligned in 18 linkage groups, which is the haploid chromosome number of the species, at LOD values ranging from 5 to 8. The total map length was 1,629 cM with an average marker interval of 3.5 cM. AFLP markers generated by EcoRI were more clustered, whereas PstI markers showed more extensive distribution. A set of 26 primer pairs (9 EcoRI/ MseI, 6 EcoRI/ TaqI, 6 PstI/ MseI and 5 PstI/ TaqI) generating 385 markers were identified for AFLP-based whole-genome selection as these markers covered 96% of the genome mapped with the 91 primer pairs. The map developed in the present study could be used for dissection and the transfer of agronomically important traits and favourable QTLs from ill-adapted exotic germplasm to cultivated Indian varieties.