Genetic Variation Analysis between Wild and Cultured Pangasianodon hypopthalmus Using COI and Cytochrome b Among Asian Countries

One of the top species in the aquaculture sector, known as striped catfish or Pangasianodon hypophthalmus, is an important and valuable freshwater fish in many countries. Due to the high demand for this species, their number has declined to "threatened" levels. Hence, the purpose of this study is to analyse the genetic variation of wild and cultured striped catfish collected from five producers in Asian countries; Thailand, Vietnam, Indonesia, India, and Philippines, by using mitochondrial DNA partial region data sequence; CO1 and cytochrome b gene. Population analyses using 395 base pairs length for CO1 and 275 base pairs length of cytochrome b partial region nucleotide sequence have shown no significance difference between wild and cultured striped catfish. Vietnam species had shown a wide range of genetic distance of the intrapopulation compared with other countries in the range of 0.000-0.040 for CO1 gene and 0.003-0.008 for cytochrome b gene. The Neighbour-joining method has also been used to construct phylogenetic trees using CO1 gene; the tree formed few subclades with mixed populations, and the tree using cytochrome b showed only Vietnam species divided into a few sub-populations. For the other four countries, Thailand, Indonesia, India, and Philippines were in the same group. Hence, this study's findings may provide a reference for inter and intra-relationships of P. hypophthalmus that may help in the aquaculture activity of this striped catfish.

Molecular identification of bats from Wavulgalge cave, Wellawaya, Sri Lanka

This is the first report on the molecular identification and phylogeny of Rousettus leschenaultii, Rhinolophus rouxii, Hipposideros speoris, Hipposideros lankadiva, Miniopterus fuliginosus bat species in Sri Lanka, inferred from mitochondrially encoded cytochrome b gene sequences. Wellawaya Wavulgalge cave in Sri Lanka is one of the largest sympatric colonies found on the island, occupied by five species of bats. Recent research has indicated that bats show enormous cryptic genetic diversity. Moreover, even in the same species, acoustic properties of echolocation calls and morphological features such as fur colour could vary in different populations. Therefore, we have used molecular techniques for the accurate identification of five bat species recorded in one of the largest cave populations in Sri Lanka. Bats were caught using a hand net and saliva samples were collected non-invasively from each bat using a sterile oral swab. Nucleic acids were extracted from oral swab samples and mitochondrial DNA was amplified using primers targeting the mitochondrially encoded cytochrome b gene. This study identified the bat species recorded in the Wellawaya cave as Rousettus leschenaultii , Rhinolophus rouxii , Hipposideros speoris , Hipposideros lankadiva and Miniopterus fuliginosus . Our findings will contribute to future conservation and systematic studies of bats in Sri Lanka. This study will also provide the basis for a genetic database of Sri Lankan bats .

Detection of species substitution in raw, cooked, and processed meats utilizing multiplex-PCR assay

The rise of beef consumption in Indonesia opens an opportunity for “rogue” suppliers to mix beef with other meat species that are relatively cheaper, such as pork, chicken, etc. The aim of this study was to identify pig and chicken meat in raw, cooked, and processed meat products using multiplex-PCR of mitochondrial DNA Cytochrome b gene, which is maternally inherited and widely used for forensic studies. A total of 90 samples-33 raw meats, 33 cooked meats, and 24 meatballs-were used in this study. Each sample was extracted to obtain the DNA genome and this was then amplified using multiplex-PCR. The PCR products were visualized using 2% agarose gel electrophoresis. The results showed that species contained in raw, cooked, and processed meat samples could be identified as indicated by DNA bands at 398, 274, 227, and 157 bp for pig, cattle, chicken, and goat species respectively. This study concluded that species substitution in raw, cooked, and processed meats could be detected using the Cytochrome b gene as a genetic marker through multiplex-PCR assay.

Non-invasive DNA extraction for molecular identification of royal Bengal tiger Panthera tigris tigris

The flagship animal species of Sundarbans, the Royal Bengal tiger (Panthera tigris tigris) is under threat of extinction. Its natural population is declining day by day. So, to avoid killing and harming the animal, the use of non-invasive samples such as scat, hair, or scent is preferred for DNA extraction and subsequent genotyping of tiger species. DNA has been extracted from scat samples of the Bengal tiger in the present study, and a fragment of the cytochrome b gene has been sequenced after PCR with species-specific primers. DNA has been extracted manually using a previously described methodology with slight modifications. The size of the PCR product and sequence of cytochrome b gene indicates that tiger DNA is successfully extracted from scat samples using tigerspecific primers. Thus, presence of tiger DNA can be detected by using this method just by the PCR product size in the gel. This is the first report of a partial sequence of mitochondrial cytochrome b gene of P. t. tigris from Bangladesh. Dhaka Univ. J. Biol. Sci. 30(2): 325-330, 2021 (July)

The role of molecular taxonomy in uncovering local ornamental Palo Fish (Betta sp.: Osphronemidae) and other Betta based on Cytochrome b gene

Cytochrome b gene mitochondrial DNA was used to study the Palo fish from Bukit Rangkak tributary, Harau Valley, West Sumatra. The study aimed to determine the taxonomy of Palo fish, which morphological suspected as the Betta group. Phylogenetic analysis was used to solve the relationship of Palo fish with other species of the Betta. The alignment of the DNA sequences was carried out with Clustal X version 2 and analysis of phylogenetic tree using MEGA 6 software program. Based on the analysis of the cytochrome b gene sequence (1047 bp), it is known that the genetic differences of Palo fish from two tributaries of Bukit Rangkak river is 0.0% and with other Betta fish ranges from 13.0-35.5%. The phylogenetic tree has shown that Palo fish has a close genetic relationship with the Betta picta (13.0%). The result showed that Palo fish is at the different species in the genus of Betta and proposed as a new species.

First genetic identification of Sundevall’s jird Meriones crassus (Rodentia, Muridae) in Morocco and the hypothesis of range extension

Rodents from the subfamily Gerbillinae Gray, 1825, are an important component of small fauna in arid and desertic regions in Africa and Asia. Among this group of rodents, Sundevall’s jird, Meriones crassus, is one of the most widespread desert species, found in countries ranging from Morocco to Pakistan. In this study, we sequenced the cytochrome b gene of the mitochondrial DNA in two specimens captured in Morocco, constituting the first genetic identification for this species in the African continent. Molecular identification was complemented and supported with morphological evidence. Additionally, we propose the hypothesis of a northward extension of 250 km of the geographic distribution of Sundevall’s jird in Morocco, perhaps indicating the increasing desertification affecting North Africa. Further evidence will be required to test the latter hypothesis. Dataset published through Zenodo (Doi: 10.5281/zenodo.4674889)