The practical proceeded in five sessions. The first session involved DNA manipulation, which involved two steps. The aim of the first step, small-scale plasmid isolation (‘Miniprep’), was to isolate a recipient plasmid, pBlue Script KS II (+), from an E. coli culture prepared the previous day. In the second exercise, a double restriction endonuclease digestion of the two plasmids, i.e., the donor (pProEX) and the recipient (pBKSII), was done using BamHI and HindIII. The aims of this step were to excise the gene of interest (Pc-FtsZ) from pProEX and prepare the recipient plasmid, pBKSII, for cloning. The two restriction endonucleases cleaved the DNA at specific sites to generate sticky ends that allowed the foreign fragment (Pc-FtsZ) to be inserted into the recipient plasmid.

Practical two involved the construction of a recombinant vector, pBKS II-ftsZ, using the restriction digests from the first lab session. Its aims were to compare the relative molecular sizes of the restriction digests with standards, confirm whether the restriction digestion was successful, and separate and purify the gene of interest for ligation. It entailed agarose gel electrophoresis to resolve the DNA into separate bands, excision to remove the desired fragments, and ligation of the gene into the pBKSII plasmid. The new pBKSII plasmid contained the Pc-ftsZ gene and could be inserted into E. coli in the next session.

The recombinant plasmids (containing Pc-ftsZ gene) from the above step were used to transform E. coli cells made competent through heat shock. The practical proceeded in two steps: (1) bacterial transformation (cloning) and (2) Southern blotting analysis of the cloned DNA. The objectives were to introduce ligated vector (pBKSII) into E. coli for cloning and analyse the cloned inserts using agarose gel electrophoresis and Southern blotting.

Since not all cells in the last session could take up the ligated vector, identifying transformed cells from the non-transformed ones was important. In the fourth practical session, an analysis of the Southern blot was done using specific probes. The main objective of this step was to confirm the presence of PC-FtsZ in the transformed bacteria. The practical also involved the screening of transformed bacteria using PCR to identify those carrying the pBKS II-Pc-ftsZ construct. The final (fifth) practical involved the screening of the Southern blot (gel) and testing the Taq polymerase colonies to confirm the results obtained in the previous session. Running a gel of the PCR colony screen obtained in the previous practical helped identify specific sequences in the transformed bacteria.

It is classified under, Kingdom Animalia, Phylum Mollusca, Class Bivalvia, Order Mytiloida, Family Mytilidae, Genus, Perna and the specific name Perna. It is among the most widely farmed bivalves in Brazil representing approximately 19% of the country’s Mariculture.

The organism’s habitat and native geographical location are often found in warm water bodies. P. Perna is indigenous to parts of Africa, Europe and South America, although it is also found in North America, where it was artificially introduced. It is usually hunted and harvested in South America where it is considered an important source of food (Abada-Boudjema, Yamina-Madiha and Dauvin 468). Ironically, it contains highly toxic substances known to destroy some marine structures. When many Mussels attach themselves to water pipes, they can course serious clogging, which disrupts the flow of water in an area. In addition, they can overwhelm and sink small marine vessels whey that cling on to them in huge clusters. However, because of its low tolerance for chorine, it is considerably easier to control compared to other types of Mussel such as the Perna viridis.

The hypothesis of the paper is that the changing seasons differently affect the levels of production of P. Perna in three Brazilian bays. The study involved various types of intensive and careful sampling so the scientists could investigate their reactions to the environments in varied seasons. Brazil was an ideal choice for the study because, among the Mussel growing countries in the world, it is the one with the biggest investment in them. The study’s findings would be used to predict when and where it was most suitable and financially prudent to grow the Mussel with optimal yields.