ORCID Profile
0000-0002-6716-4515
Current Organisation
The Graduate University for Advanced Studies
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Publications
Characterisation of major histocompatibility complex class I genes in Japanese Ranidae frogs
Publisher: Springer Science and Business Media LLC
Date: 14-07-2016
An application of PCR-RFLP species identification assay for environmental DNA detection
Publisher: PeerJ
Date: 19-03-2019
DOI: 10.7287/PEERJ.PREPRINTS.27601V1
Abstract: Recent advancement of eDNA methods for surveying species in aquatic ecosystems has been used for various organisms and contributed to monitoring and conservation of species and environments. Amphibians are one of the promising taxa which could be monitored efficiently by using eDNA. However, the cost of the eDNA detection can be quite high and requires instruments that are not usually installed in ecology laboratories. For aiding researchers foraying into eDNA studies of hibians, especially those not specialized in molecular biology, we developed a cost efficient protocol using PCR-RFLP method. We attempted to detect eDNA of three Japanese Rana species ( R. japonica, R. ornativentris, and R. tagoi tagoi ) in various spatial scales including an area close to the Fukushima Nuclear Power Plant (FNPP) where the environment is recovering after the disaster in 2011. Our PCR-RFLP protocol was successful in detecting Rana species in static water in both laboratory and field however, it could not detect Rana species in non-static water s les from the field. Even a more sensitive detection method (standard qPCR) was unable to detect frogs in all non-static water s les. We speculate that our new protocol is effective for frogs living in lentic habitats, but not for lotic habitats which may still require the gold standard of field observation for detection approach.
Genetic potential for disease resistance in a critically endangered frog decimated by chytridiomycosis
Publisher: Cold Spring Harbor Laboratory
Date: 18-11-2018
DOI: 10.1101/247999
Abstract: Southern corroboree frogs ( Pseudophryne corroboree ) have been driven to functional extinction in the wild after the emergence of the hibian fungal pathogen Batrachochytrium dendrobatidis ( Bd ) in southeastern Australia in the 1980s. This species is currently maintained in a captive assurance colony and is managed to preserve the genetic ersity of the founding populations. However, it is unlikely that self-sustaining wild populations can be re-established unless Bd resistance increases. We performed a Bd -challenge study to investigate the association between genetic variants of the major histocompatibility complex class IA (MHC) and genome-wide single nucleotide polymorphisms (SNPs). We also investigated differences in Bd susceptibility among in iduals and populations, and the genetic ersity and population genetic structure of four natural P. corroboree populations. We found several MHC alleles and SNPs associated with Bd infection load and survival, provide evidence of significant structure among populations, and identified population-level differences in the frequency of influential variants. We also detected evidence of positive selection acting on the MHC and a subset of SNPs as well as evidence of high genetic ersity in P. corroboree populations. We suggest that low interbreeding rates may have contributed to the demise of this species by limiting the spread of Bd resistance genes. However, our findings demonstrate that despite dramatic declines there is potential to restore high levels of genetic ersity in P. corroboree . Additionally, we show that there are immunogenetic differences among captive southern corroboree frogs, which could be manipulated to increase disease resistance and mitigate the key threatening process, chytridiomycosis.
An application of PCR-RFLP species identification assay for environmental DNA detection
Publisher: PeerJ
Date: 03-10-2019
DOI: 10.7717/PEERJ.7597
Abstract: Recent advancement of environmental DNA (eDNA) methods for surveying species in aquatic ecosystems has been used for various organisms and contributed to monitoring and conservation of species and environments. Amphibians are one of the promising taxa which could be monitored efficiently by applying quantitative PCR (qPCR) or next generation sequencing to eDNA. However, the cost of eDNA detection using these approaches can be quite high and requires instruments that are not usually installed in ecology laboratories. For aiding researchers in starting eDNA studies of hibians, especially those not specialized in molecular biology, we developed a cost efficient protocol using PCR-RFLP method. We attempted to detect eDNA of three Japanese Rana species ( Rana japonica, Rana ornativentris , and Rana tagoi tagoi ) in various spatial scales including an area close to the Fukushima nuclear power plant where the environment is recovering after the disaster in 2011. Our PCR-RFLP protocol was successful in detecting Rana species in static water in both laboratory and field however, it could not detect Rana species in non-static water s les from the field. Even a more sensitive detection method (standard qPCR) was unable to detect frogs in all non-static water s les. We speculate that our new protocol is effective for frogs living in lentic habitats, but not for lotic habitats which may still require the gold standard of field observation for detection approach.
Transcriptome analyses of immune tissues from three Japanese frogs (genus Rana ) reveals their utility in characterizing major histocompatibility complex class II
Publisher: Springer Science and Business Media LLC
Date: 12-2017
Expression profiles of the immune genes CD4, CD8β, IFNγ, IL-4, IL-6 and IL-10 in mitogen-stimulated koala lymphocytes (Phascolarctos cinereus) by qRT-PCR.
Publisher: PeerJ
Date: 04-03-2014
DOI: 10.7717/PEERJ.280
Diversity of MHCDQBandDRBGenes in the Endangered Australian Sea Lion (Neophoca cinerea)
Publisher: Oxford University Press (OUP)
Date: 2015
Abstract: Major histocompatibility complex (MHC) class II molecules have an important role in vertebrate adaptive immunity, being responsible for recognizing, binding, and presenting specific antigenic peptides to T lymphocytes. Here, we study the MHC class II DQB and DRB exon 2 genes of the Australian sea lion (Neophoca cinerea), an endangered pinniped species that experiences high pup mortality. Following characterization of N. cinerea DQB and DRB by molecular cloning, and evaluation of ersity in pups across 2 colonies using variant screening (n = 47), 3 DQB alleles and 10 DRB variants (including 1 pseudogene allele) were identified. The higher ersity at DRB relative to DQB is consistent with other studies in marine mammals. Despite overall lower MHC class II allelic ersity relative to some other pinniped species, we observed similar levels of nucleotide ersity and selection in N. cinerea. In addition, we provide support for recent ergence of MHC class II alleles. The characterization of MHC class II ersity in the Australian sea lion establishes a baseline for further investigation of associations with disease, including endemic hookworm infection, and contributes to the conservation management of this species.
Expression and in vitro upregulation of MHCII in koala lymphocytes.
Publisher: Elsevier BV
Date: 06-2012
DOI: 10.1016/J.VETIMM.2012.04.010
Abstract: Understanding and measuring immune activity of the koala (Phascolarctos cinereus), is important to studies of the epidemiology and impact of the widespread chlamydial and koala retroviral (KoRV) infections that occur in this iconic but increasingly threatened species. To explore the interaction of disease and immunity, and to assess the potential for use of class II major histocompatibility complex (MHCII) upregulation as an indicator of lymphocyte activation in in vitro immune assays, we have investigated the expression of MHCII in koala lymphocytes by flow cytometry. MHCII expression was upregulated in mitogen stimulated B lymphocytes in vitro but no such increase was detected in vivo in free-living koalas with active inflammation. In assessing phenotypic baseline data of captive koalas, we have identified that MHCII is expressed predominantly on circulating B lymphocytes (85.7 ± 2.4%) but on very few T lymphocytes (3.4 ± 1.9%), even following activation, and suggest that the latter finding might be compensated by the greater absolute numbers of peripheral blood B lymphocytes in this species relative to many eutherian species.
Characterisation of four major histocompatibility complex class II genes of the koala (Phascolarctos cinereus).
Publisher: Springer Science and Business Media LLC
Date: 23-10-2013
DOI: 10.1007/S00251-012-0658-5
Abstract: Major histocompatibility complex (MHC) class II molecules have an integral role in the adaptive immune response, as they bind and present antigenic peptides to T helper lymphocytes. In this study of koalas, species-specific primers were designed to lify exon 2 of the MHC class II DA and DB genes, which contain much of the peptide-binding regions of the α and β chains. A total of two DA α1 domain variants and eight DA β1 (DAB), three DB α1 and five DB β1 variants were lified from 20 koalas from two free-living populations from South East Queensland and the Port Macquarie region in northern New South Wales. We detected greater variation in the β1 than in the α1 domains as well as evidence of positive selection in DAB. The present study provides a springboard to future investigation of the role of MHC in disease susceptibility in koalas.
Primers for amplifying major histocompatibility complex class II DQB and DRB exon 2 in the Australian sea lion (Neophoca cinerea)
Publisher: Springer Science and Business Media LLC
Date: 14-06-2014
The adaptor protein APPL1 increases glycogen accumulation in rat skeletal muscle through activation of the PI3-kinase signalling pathway
Publisher: Bioscientifica
Date: 04-05-2011
DOI: 10.1530/JOE-11-0039
Abstract: APPL1 is an adaptor protein that binds to both AKT and adiponectin receptors and is hypothesised to mediate the effects of adiponectin in activating downstream effectors such as AMP-activated protein kinase (AMPK). We aimed to establish whether APPL1 plays a physiological role in mediating glycogen accumulation and insulin sensitivity in muscle and the signalling pathways involved. In vivo electrotransfer of cDNA- and shRNA-expressing constructs was used to over-express or silence APPL1 for 1 week in single tibialis cranialis muscles of rats. Resulting changes in glucose and lipid metabolism and signalling pathway activation were investigated under basal conditions and in high-fat diet (HFD)- or chow-fed rats under hyperinsulinaemic–euglycaemic cl conditions. APPL1 over-expression (OE) caused an increase in glycogen storage and insulin-stimulated glycogen synthesis in muscle, accompanied by a modest increase in glucose uptake. Glycogen synthesis during the cl was reduced by HFD but normalised by APPL1 OE. These effects are likely explained by APPL1 OE-induced increase in basal and insulin-stimulated phosphorylation of IRS1, AKT, GSK3β and TBC1D4. On the contrary, APPL1 OE, such as HFD, reduced AMPK and acetyl-CoA carboxylase phosphorylation and PPARγ coactivator-1α and uncoupling protein 3 expression. Furthermore, APPL1 silencing caused complementary changes in glycogen storage and phosphorylation of AMPK and PI3-kinase pathway intermediates. Thus, APPL1 may provide a means for crosstalk between adiponectin and insulin signalling pathways, mediating the insulin-sensitising effects of adiponectin on muscle glucose disposal. These effects do not appear to require AMPK. Activation of signalling mediated via APPL1 may be beneficial in overcoming muscle insulin resistance.
Koala immunology and the koala retrovirus (KoRV)
Publisher: Australian Museum
Date: 29-05-2014
Living in a Japanese onsen: field observations and physiological measurements of hot spring amphibian tadpoles, Buergeria japonica
Publisher: Brill
Date: 2016
DOI: 10.1163/15685381-00003052
Abstract: The Japanese stream tree frog, Buergeria japonica , is widely distributed across the southern islands of Japan and Taiwan. While the species is known to inhabit hot springs, this has only been reported in Taiwan. To further understand the utilization of hot springs by B. japonica , we conducted field observations of tadpoles from a hot spring on Kuchinoshima Island, a tiny volcanic island of southwestern Japan. We found that tadpoles on Kuchinoshima Island inhabited hot spring pools with extremely high temperatures that exceeded temperatures in which any other hibians have been found. In addition, we conducted thermal tolerance measurements and found that the thermal tolerance of B. japonica tadpoles was high. These findings suggest that high thermal tolerance of B. japonica is maintained even at the northern tip of its distribution, and this has allowed them to widen their available niche and inhabit a hot spring on the tiny island of Kuchinoshima.
Heterogeneity of synonymous substitution rates in the Xenopus frog genome
Publisher: Public Library of Science (PLoS)
Date: 07-08-2020
Primers for amplifying major histocompatibility complex class II DQB and DRB exon 2 in the Australian sea lion (Neophoca cinerea)
Publisher: Springer Science and Business Media LLC
Date: 14-06-2014
Local activation of the IkappaK-NF-kappaB pathway in muscle does not cause insulin resistance.
Publisher: American Physiological Society
Date: 02-2008
DOI: 10.1152/AJPENDO.00537.2007
Abstract: Insulin resistance of skeletal muscle is a major defect in obesity and type 2 diabetes. Insulin resistance has been associated with a chronic subclinical inflammatory state in epidemiological studies and specifically with activation of the inhibitor κB kinase (IκBK)-nuclear factor-κB (NF-κB) pathway. However, it is unclear whether this pathway plays a role in mediating insulin resistance in muscle in vivo. We separately overexpressed the p65 subunit of NF-κB and IκBKβ in single muscles of rats using in vivo electrotransfer and compared the effects after 1 wk vs. paired contralateral control muscles. A 64% increase in p65 protein ( P 0.001) was sufficient to cause muscle fiber atrophy but had no effect on glucose disposal or glycogen storage in muscle under hyperinsulinemic-euglycemic cl conditions. Similarly, a 650% increase in IκBKβ expression ( P 0.001) caused a significant reduction in IκB protein but also had no effect on cl glucose disposal after lipid infusion. In fact, IκBKβ overexpression in particular caused increases in activating tyrosine phosphorylation of insulin receptor substrate-1 (24% P = 0.02) and serine phosphorylation of Akt (23% P 0.001), implying a moderate increase in flux through the insulin signaling cascade. Interestingly, p65 overexpression resulted in a negative feedback reduction of 36% in Toll-like receptor (TLR)-2 ( P = 0.03) but not TLR-4 mRNA. In conclusion, activation of the IκBKβ-NF-κB pathway in muscle does not seem to be an important local mediator of insulin resistance.
Identification of MHCII variants associated with chlamydial disease in the koala (Phascolarctos cinereus).
Publisher: PeerJ
Date: 19-06-2014
DOI: 10.7717/PEERJ.443
MHC class II diversity of koala (Phascolarctos cinereus) populations across their range.
Publisher: Springer Science and Business Media LLC
Date: 02-04-2014
DOI: 10.1038/HDY.2014.30
Related Organisations
Related Funding Activities
No related grants have been discovered for Quintin Lau.