Evaluation of polyherbal feed supplement (Ban-V) on the enhancement of growth and non-specific immune responses in shrimp Penaeus vannamei

Owing to the growing need for eco-friendly aquaculture, usage of herbal feed supplement receives higher attention. A commercial shrimp feed supplement known as Ban-V is a unique blend of polyherbal extracts that act synergistically with each other to help in improving the immune system, protects hepatopancreas and activates several metabolic pathways for better growth and disease resistance. For that, four supplemental concentrations such as 0.5, 1.0, 2.0 and 3.0 % of Ban-V were used along with commercial shrimp feed, and feed with no supplement (control) were evaluated for 60 days. Results revealed that 2.0% of Ban-V diet fed group showed significantly increased biological performance like (average body weight, average daily growth, feed conversion ratio and survival rate) than control. The tested immunological parameters such as total haemocyte count, oxyhaemocyanin level, phenoloxidase (PO) activity, respiratory burst activity (RB), superoxide dismutase (SOD), lysozyme activity, plasma protein content (PPC) and bactericidal activity were higher in 2.0% test diet fed P. vannamei, when compared to other test and control diet fed shrimp. It is therefore suggested that Ban-V supplementation at a concentration of 2.0% was efficient in stimulating the growth and immunity in shrimp.

     

Immune responses against Marek's disease virus

It is more than a century since Marek's disease (MD) was first reported in chickens and since then there have been concerted efforts to better understand this disease, its causative agent and various approaches for control of this disease. Recently, there have been several outbreaks of the disease in various regions, due to the evolving nature of MD virus (MDV), which necessitates the implementation of improved prophylactic approaches. It is therefore essential to better understand the interactions between chickens and the virus. The chicken immune system is directly involved in controlling the entry and the spread of the virus. It employs two distinct but interrelated mechanisms to tackle viral invasion. Innate defense mechanisms comprise secretion of soluble factors as well as cells such as macrophages and natural killer cells as the first line of defense. These innate responses provide the adaptive arm of the immune system including antibody- and cell-mediated immune responses to be tailored more specifically against MDV. In addition to the immune system, genetic and epigenetic mechanisms contribute to the outcome of MDV infection in chickens. This review discusses our current understanding of immune responses elicited against MDV and genetic factors that contribute to the nature of the response.     

Development of PCR assay for differentiation of some important wild animal meat of Sri Lanka

A polymerase chain reaction (PCR) assay was developed to differentiate meat of Ceylon spotted deer (Axis axis ceylonensis), Ceylon hog deer (A. porcius oryzus), Ceylon sambhur (Cervus unicolor unicolor) and barking deer (Muntiacus muntijak malabaricus) from meat of cattle, goat, buffalo, pig, dog and sheep. A set of primers was designed according to the sequence of the mitochondrial cytochrome b gene of C. elaphus canadensis and by PCR amplification about 450 bp band was observed for all four animal species and these primers were not cross reacted with DNA of other animal species tested in the study under the tested reaction conditions. A band of 649 bp size was observed for all animal species when DNA was amplified with the universal primers and that indicated the presence of mitochondrial DNA in the samples. Further, the results indicated that this technique was sensitive enough to differentiate rotten meat, at least 5 days after the killing of an animal. Under these PCR conditions, the DNA of bacteria, which is involved in decomposition of meat, was not amplified with both universal and specific primers. However, the method was not sensitive enough in differentiating cooked meat of these species. Slaughtering of these four wild animal species is banned, but the animals are being killed illegally. Lack of meat identification methods has been identified as one of the major constraints to implement legal procedures and conserve biodiversity in the country.     

Self-assembling protein microarrays

Protein microarrays provide a powerful tool for the study of protein function. However, they are not widely used, in part because of the challenges in producing proteins to spot on the arrays. We generated protein microarrays by printing complementary DNAs onto glass slides and then translating target proteins with mammalian reticulocyte lysate. Epitope tags fused to the proteins allowed them to be immobilized in situ. This obviated the need to purify proteins, avoided protein stability problems during storage, and captured sufficient protein for functional studies. We used the technology to map pairwise interactions among 29 human DNA replication initiation proteins, recapitulate the regulation of Cdt1 binding to select replication proteins, and map its geminin-binding domain.