Species composition and hybridisation of mussel species (Bivalvia: Mytilidae) in Australia

Mussels belonging to the Mytilus edulis species complex have been the focus of numerous studies exploring the systematics and origin of this commercially and ecologically important genus. Species have wide geographical ranges and hybridise where their distributions overlap, making identification difficult. Several molecular markers have been used to distinguish between the species within the M. edulis species complex; however, no single marker system has been found to be completely diagnostic, and a combination of markers are used. Here, we used a combination of three nuclear genes and a mitochondrial gene region to assess the species composition of Mytilus mussels collected across its geographical range in Australia. Our results show that the majority (98.5%) of individuals sampled from Australian populations are Mytilus galloprovincialis, with 56.2% of them displaying a southern hemisphere haplotype, 10.3% displaying a putatively northern hemisphere haplotype, and 32% having M. galloprovincialis genotypes consistent with either northern or southern hemisphere M. galloprovincialis lineages. The taxonomic origin of the remaining 1.5% of samples (n ¼ 3) could not be conclusively determined. Our results suggest that there have been significant introductions of non-native M. galloprovincialis lineages into both southern and northern hemisphere populations.

Bio-conjugation of antioxidant peptide on surface-modified gold nanoparticles: a novel approach to enhance the radical scavenging property in cancer cell

BACKGROUND: Functionalized gold nanoparticles are emerging as a promising nanocarrier for target specific delivery of the therapeutic molecules in a cancer cell, as a result it targeted selectively to the cancer cell and minimized the off-target effect. The functionalized nanomaterial (bio conjugate) brings novel functional properties, for example, the high payload of anticancer, antioxidant molecules and selective targeting of the cancer molecular markers. The current study reported the synthesis of multifunctional bioconjugate (GNPs-Pep-A) to target the cancer cell. METHODS: The GNPs-Pep-A conjugate was prepared by functionalization of GNPs with peptide-A (Pro-His-Cys-Lys-Arg-Met; Pep-A) using thioctic acid as a linker molecule. The GNPs-Pep-A was characterized and functional efficacy was tested using Retinoblastoma (RB) cancer model in vitro. RESULTS: The GNPs-Pep-A target the reactive oxygen species (ROS) in RB, Y79, cancer cell more effectively, and bring down the ROS up to 70 % relative to control (untreated cells) in vitro. On the other hand, Pep-A and GNPs showed 40 and 9 % reductions in ROS, respectively, compared to control. The effectiveness of bioconjugate indicates the synergistic effect, due to the coexistence of both organic (Pep-A) and inorganic phase (GNPs) in novel GNPs-Pep-A functional material. In addition to this, it modulates the mRNA expression of antioxidant genes glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) by two-threefolds as observed. CONCLUSIONS: The effects of GNPs-Pep-A on ROS reduction and regulation of antioxidant genes confirmed that Vitis vinifera L. polyphenol-coated GNPs synergistically improve the radical scavenging properties and enhanced the apoptosis of cancer cell.

Fresh and cultured buccal cells as a source of mRNA and protein for molecular analysis

We developed a method for obtaining viable buccal cells from mouthwash samples for use as a source of mRNA and protein. Immunofluorescent analysis showed that most cells were derived from nonkeratinized parabasal epithelia, with a minor proportion of proliferative cells. Gene expression was detected in buccal cells using reverse transcription PCR, Western blot analysis, and immunofluorescence. Using a keratinocyte-specific medium, buccal cells could be cultured on Matrigel™-coated permeable filters for up to 2 weeks while maintaining the expression of some epithelial-specific markers, including cytokeratin 13, cytokeratin 10, transferrin receptor, and β-integrin. The basal marker cytokeratin 14 and Ki67, an indicator of cellular proliferation, were detected in a few cells. We show that buccal cells can be obtained from a noninvasive procedure for use as a source of material for biochemical analyses. A population of the buccal cells can be maintained in culture for up to 2 weeks using keratinocyte-specific medium in combination with extracellular matrix.

Development of molecular techniques for the genetic analysis of abalone populations

Three DNA techniques: random amplified polymorphic DNA (RAPD), minisatellite, and microsatellite analyses, were developed for use in abalone population genetic structure studies. The techniques were assessed using sample sets of blacklip and greenlip abalone. The study identifies a potential for the application of these DNA markers in abalone fisheries management, but microsatellites are the recommended method for future studies.

Major histocompatibility complex (MHC) markers in conservation biology

Human impacts through habitat destruction, introduction of invasive species and climate change are increasing the number of species threatened with extinction. Decreases in population size simultaneously lead to reductions in genetic diversity, ultimately reducing the ability of populations to adapt to a changing environment. In this way, loss of genetic polymorphism is linked with extinction risk. Recent advances in sequencing technologies mean that obtaining measures of genetic diversity at functionally important genes is within reach for conservation programs. A key region of the genome that should be targeted for population genetic studies is the Major Histocompatibility Complex (MHC). MHC genes, found in all jawed vertebrates, are the most polymorphic genes in vertebrate genomes. They play key roles in immune function via immune-recognition and -surveillance and host-parasite interaction. Therefore, measuring levels of polymorphism at these genes can provide indirect measures of the immunological fitness of populations. The MHC has also been linked with mate-choice and pregnancy outcomes and has application for improving mating success in captive breeding programs. The recent discovery that genetic diversity at MHC genes may protect against the spread of contagious cancers provides an added impetus for managing and protecting MHC diversity in wild populations. Here we review the field and focus on the successful applications of MHC-typing for conservation management. We emphasize the importance of using MHC markers when planning and executing wildlife rescue and conservation programs but stress that this should not be done to the detriment of genome-wide diversity.

Sympatric cryptic species in the crinoid genus Cenolia (Echinodermata: Crinoidea: Comasteridae) delineated by sequence and microsatellite markers

The marine species of the southern coast of Australia have not been well studied with regard to molecular connectivity. Cryptic species are expected to be prevalent on this coastline. Here, we investigate the crinoid genus Cenolia (Echinodermata: Crinoidea: Comasteridae) using molecular methods to elucidate cryptic species and phylogenetic relationships. The genus Cenolia dominates the southern Australian crinoid fauna in shallow waters. Few studies have examined crinoids for cryptic species at a molecular level and these have been predominantly based on mitochondrial data. We employ the nuclear markers 28S rRNA and ITS-2 in addition to the mitochondrial COI. Six divergent mitochondrial clades were identified. Gene flow between confirmed clades was subsequently examined by the use of six novel microsatellite markers, showing that sympatric taxa with low mtDNA divergences (1.7% K2P) were not interbreeding in the wild. The type specimens of Cenolia benhami and C. spanoschistum were examined, as well as all six divergent clades. Morphological characters dividing taxa were refined. Due to comb pinnule morphology, the New Zealand species benhami was determined to belong to the genus Oxycomanthus (nov. comb.). Three new species of Cenolia (including the Australian "benhami") require description. © 2014 Elsevier Inc.

Molecular insights and oligonucleotide based targeted gene therapy against cancer

The thesis helps to unravel the function of T lymphoma invasion and metastasis protein (TIAM1) and nucleolin, a nucleolar protein in retinoblastoma tumorigenesis. Aptamer based targeted imaging; drug and gene delivery to retinoblastoma and epithelial cancer cells was attained. The work work finally opened up avenues for cancer stem cell targeting using aptamers, imaging of cancer cells using novel bio-orthogonal agent and use of aptamer for blocking the miRNA-17-92 cluster maturation.