The Gene Pool for Philippine carabao (Bubalus bubalis) swamp buffalo for conservation and management is at PCC at Cagayan State University (PCC at CSU). With its current efforts to preserve the live population of swamp buffaloes with superior genetics, the question is whether the conservation at PCC at CSU is enough to represent the Philippine carabao’s genetics in the country. Is there a genetic diversity of this indigenous animal? How would we know if the answer is “YES” or “NO”? First, a conclusive molecularbased approach to Philippine carabao genetic diversity using informative genetic markers is necessary.

Molecular markers are powerful tools for understanding evolution and genetic diversity based on the sequence variation of deoxyribonucleic acid or DNA, which contains molecules to code for genetic information needed by an organism to develop, grow, and function. For instance, mitochondrial DNA (mtDNA) has been widely used in understanding the relationship of organisms relative to another organism of the same species. In the Philippines, the COI gene marker revealed its usefulness in discriminating breeds of B. bubalis swamp buffalo from the riverine and confirming the identity of Calayan swamp buffaloes into its subspecies level. However, information extracted from mtDNA could be limited to the maternal lineage.

Therefore, another genetic marker from a nuclear gene is vital to support mitochondrial information. This pertains to the microsatellites.

So, what are the microsatellite genetic markers? Each microsatellite tags a particular region in the cell from two copies of genetic material, one inherited from the mother and another from the father. Microsatellites are also helpful because these are abundant in the genome, which refers to a cell’s entire DNA instructions. In addition, these have a high degree of variability in the repeat sequence, making them informative markers used to understand population genetics, parentage testing, and individual identification.

The Food and Agriculture Organization recommended 30 microsatellite loci that can be used to assess the genetic diversity and population structure among buffaloes. However, the characterization and optimization of informative microsatellite markers were suggested in developing the genetic maps. These microsatellite markers were previously used to determine the genetic diversity of Southeast Asian buffalo breeds but have not fully applied to the Philippine carabao sub-populations. Therefore, considering the potential of microsatellite markers, it is necessary first to evaluate the utility of these markers in genotyping the Philippine carabao.

To determine the genetic diversity of PC, the DA-PCC Animal Genetic Resources team evaluated the 30 FAO microsatellite marker for the information content and its potential efficacy for recommending a set of marker panels for genetic diversity and parentage testing of Philippine carabao. In this study, 488 fresh blood samples of Philippine carabao were randomly selected from 27 populations of the Luzon, Visayas, and Mindanao islands.

The overall research findings highlighted the 27 microsatellite markers that are highly and reasonably informative, which confirms their usefulness in determining the genetic diversity of the Philippine carabao subpopulations. Therefore, these markers should be helpful for genetic population analysis, which implies identifying possible population structures that could be a basis for strengthening Philippine carabao conservation management. Moreover, three loci showed potential use in forensic studies with 73.8% combined power of exclusion and 99.5% combined discriminatory power to distinguish samples from different individuals. This implies the potential efficacy of three loci that could be considered for future forensic studies. However, increasing the number of loci is recommended to achieve higher statistical power suitable for forensic applications such as paternity testing in the PC population.