Molecular and phylogenic identification of Gammarus komareki species (Gammaridae) from the Jajrood River using DNA barcoding method

Document Type : Research Paper

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Abstract

Gammarus (Crustacea: Amphipoda) are Gammaridae family that play an important role in food chain, environmental refining of organic matter and high sensitivity to environmental contamination. Therefore, it is important to identify them. Since the identification of the genus Gammarus is very difficult due to similar morphological features, the aim of the present study was to molecular identification and investigation of the phylogenetic relationships of G. komareki from the Jajrood River, east ofTehran compared to other parts of Iran and the rest of the world. For this purpose, sampling of G. komareki species in Jajrood River was done in season from October 2013 to July 2014. Samples were collected by a small manual tour. For molecular studies, some tissue was isolated from each sample with scalpel and fixed in 95% ethyl alcohol. The DNA of the samples was then extracted using the CTAB method and the gene fragment of a mitochondrial cytochrome oxidase (COI) subunit was amplified and sequenced. After gene fragment amplification and sequencing, Neighbor Joining and Maximum Likelihood trees were plotted using MEGA7 software. The results of the present study showed that although the specimens were morphologically belonging to Gammarus komareki species reported from other parts of Iran, however, they were completely separated in genetic clades for genetic studies. Therefore, it is likely that they belong to different species, which needs further investigation with other genetic markers.

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