Cloning, expression and molecular analysis of recombinant Netrin-A protein of Lucilia sericata Meigen (Diptera: Calliphoridae) larvae

Objectives

Lucilia sericata (Diptera: Calliphoridae) is used in larval therapy for wound healing. Netrin-A is an enzyme secreted from the salivary glands of these larvae, and has a central role in neural regeneration and angiogenesis. This study aimed to produce the recombinant Netrin-A protein from Lucilia sericata larvae by the baculovirus expression vector system in the Sf9 insect cell line.

Methods

The coding sequence of Netrin-A was cloned, amplified in the pTG19 vector, and then cloned in the pFastBac HTA vector. It was then transformed into DH10Bac, and the recombinant Bacmid was subsequently transfected into Sf9 cells. The recombinant Netrin-A was purified by Ni-NTA agarose. The evaluation was done using SDS-PAGE and western blot, respectively. Finally, its concentration was calculated with the Bradford assay.

Results

The molecular weight of this protein was 52 kDa with 404 amino acids. The signal peptide was located between amino acids 24 and 25. The concentration of Netrin-A was calculated to be 48.8 μg/ml. It reaffirmed the characterized gene codes of Lucilia sericata Netrin-A in a previous study.

Conclusions

The generation of recombinant Netrin-A could be used in larval therapy, and as a biomarker in certain diseases. The netrin-A of Lucilia sericata was unprecedentedly cloned and expressed in a eukaryotic cell line. Given that this larva is FDA-approved, and non-pathogenic, it conduces to research on the development of maggot therapy in future.

Entomological study of sand flies (Diptera: Psychodidae: Phlebotominae) in Asalouyeh, the heartland of an Iranian petrochemical industry

OBJECTIVE

TO INVESTIGATE THE FAUNA AND SEASONAL ACTIVITY OF DIFFERENT SPECIES OF SAND FLIES (DIPTERA: Psychodidae: Phlebotominae) in Asalouyeh, the heartland of an Iranian petrochemical industry, Southern Iran, as a oil rich district. Sand flies are the vectors of at least three different kinds of disease, the most important of which is leishmaniasis, and it is a major public health problem in Iran with increased annual occurrence of clinical episodes.

METHODS

A total of 3 497 sand flies of rural regions were collected by sticky traps fixed, and cleared in puris medium and identified morphologically, twice a month from April to March 2008.

RESULTS

Predominant species included four of genus Phlebotomus (Phlebotomus alexandri Sinton, 1928, Phlebotomus papatasi Scopoli, 1910, Phlebotomus bergeroti Parrot and Phlebotomus sergenti Parrot) and one of genus Sergentomyia (Sergentomyia tiberiadis Alder, Theodor & Lourie, 1930). The most prevalent species was Phlebotomus papatasi, presented 56.4% of the identified flies. The others were Phlebotomus sergenti (22.5%), Phlebotomus alexandri (4.5%), Phlebotomus bergeroti (12%) and Sergentomyia tiberiadis (5%) as well. The percentage of females (68%) was more than that of males (32%). The abundance of sand flies represented two peaks of activity; one in early May and the other one in the first half of September in the region.

CONCLUSION

Phlebotomus papatasi is the probable vector of zoonotic cutaneous leishmaniasis in the region. Further molecular studies are needed to determine the definite vector of the region.