The results of the genetic study of the Tal-Kaċċa dog breed were presented at the Mnarja show which is held every year on June 29 at Buskett. The venue was particularly appropriate.
Although it dates back to the ancient Roman pagan festival called the Luminaria, the Mnarja festival as we know it today has been held in Buskett since 1854 when the British Governor of Malta, William Reid, first established it as an agricultural show where farmers were encouraged to display their finest livestock and produce.
Today, the Mnarja festival continues to reflect Reid’s vision, and a traditional feature is the presence of Tal-Kaċċa dogs, which accompany so many farmers and hunting-dog fanciers.
It was, in fact, a year ago at the Mnarja festival that the project to conduct the pilot study of this breed was initiated. The study aims to determine if there was sufficient scope for establishing Tal-Kaċċa as a potential new breed.
The Tal-Kaċċa dog is very much a local breed. People in the know will tell you it bears distinct similarities to pointing dog breeds in neighbouring countries – in particular the French Braques de L’Ariege and, to a lesser extent, the Italian Bracco.
Both these breeds are established and recognised internationally. But Tal-Kaċċa had never been regarded as a potential breed in its own right. Until now.
A year ago, a team headed by James Galea, a local breeder of the Bracco Italiano and English Pointer, Lucas Micallef, a representative of the FKNK, Andrew Portelli, a Tal-Kaċċa and English Pointer breed enthusiast, and myself attended the Mnarja festival to initiate the pilot study of those Tal-Kaċċa dogs that were submitted by interested owners.
As reported on The Sunday Times of Malta (June 22, 2014), we documented characteristics, took photographs, measurements and mouth swabs from Tal-Kaċċa dogs for DNA testing. In all, we collected samples from 20 dogs, which was deemed statistically sufficient for this pilot study.
The study was entrusted to a leading UK-based laboratory. The pilot study enabled the laboratory to determine whether the swabs submitted for testing have sufficient DNA characteristics to be recognised as a separate breed and also what relationships and ancestry it may have to other breeds.
DNA testing is a very precise science and is based on the knowledge of the sequence of a number of proteins in the nucleus of the cells of the samples available. The DNA of each and every cell is exactly similar and particular to that body or, in the case of our study, a dog.
DNA testing can be performed on tissue samples, blood samples or taken as scrapings from the inside of the mouth. This latter technique was the method used at the Mnarja show last year when we collected samples. The information gathered using such methods is then studied to establish similarities and differences.
Breed has a unique identifiable genetic profile with a long history behind it
At least 240 different protein sequences need to be examined for each sample to have a significant result. This is because of the large number of variations possible. Suffice it to say that the DNA laboratory is in possession of a genetic database by which it can positively identify over 200 different breeds of dogs worldwide. It was therefore with great satisfaction that all samples from the dogs at the Mnarja show last year achieved this threshold and could be used for this study. The study comprised three distinct phases.
The first part consisted of examining the similarities samples submitted for DNA testing had with all 200 known breeds on the DNA database. The conclusion from this phase was that the Tal-Kaċċa samples were closest to a selection of pointer-type breeds. This might imply shared ancestry at some point in the past.
The second phase consisted of a complicated mathematical pro-ject called principal component analysis, which allows the data to be plotted on a 3D-graph for a clearer picture of the purity of the dogs’ ancestry, or to establish if they have a mixed-breed ancestry.
The breeds identified as having the closest genetic composition in the first part of this study were used as a point of reference for this second phase. These included in order of significance: German Shorthaired Pointer; Pointing Griffon; American Water Spaniel; and English Pointer. Other breeds were also checked according to diminishing relevance.
It was exciting to learn that the conclusions of this second part of the study resulted in an excellent separation of the Tal-Kaċċa samples into an individual cluster just like the other breeds. This means that they had very good viability to be tested as a unique breed in its own right.
The third phase featured a study of the homozygosity of the Tal-Kaċċa samples submitted as a whole group. Homozygosity is the method by which the amount or percentage of similar genes on each of the two strands of DNA is shared between the dogs used in the study. If the results show a very low amount of homozygosity, this indicates that Tal-Kaċċa is a very new breed or one with a lot of different ancestry.
If the results show a too high amount of homozygosity, this indicates that there is considerable inbreeding and lack of genetic diversity. The results so far for the sample of 20 dogs found a healthy homozygosity level which was neither too low nor too high.
Results show in fact that for the first time a reputable international laboratory has a recorded genetic profile of a significant number of Tal-Kaċċa dogs and also that the breed has a unique identifiable genetic profile with a long history behind it.
This is the beginning rather than the end, and in collaboration with all parties involved in the determination of the next phase of the pro-ject – the phenotyping and standardisation of the breed as well as health issues – this study will serve as another step for the Tal-Kaċċa dog to be hopefully seen as a breed of internationally recognition.
We have every reason to be proud of the heritage and lineage of our domestic animals and to avoid that breeds and species endemic to the Maltese Islands become extinct.
With dogs, this is a real danger that comes from a lack of breeding or dilution with other breeds, as has sadly happened with so many ancient European dog breeds.
thisweekwiththevet@gmail.com
Dr Martin Debattista is a veterinary surgeon.