How long does the actual test take, physically?
We aim to turnaround samples within 14 days of receipt. Samples are analysed every week and the samples that come in one week are slotted in to the run of the following week.
Does Genetic Solutions “own” or have patented this gene?
Genetic Solutions has a world-wide exclusive license to the patent owned by CSIRO (Australian Research Organisation like USDA). The patent describes the sequence associated with the effect on marbling. It has been granted in Australia and the United States.
Who owns the results; the sample sender, the owner of the animal, or Genestar?
Whomever submits the sample and pays for the test owns the result according to the contract signed by the client. GeneSTAR is a product, not a company.
An animal has two copies of the Genestar marbling gene, does this mean there are actually two sets of the exact same gene present?
All animals have two copies of a full set of chromosomes, one inherited from the father and one from the mother. Each set of chromosomes contains all genes. These genes can occur in different forms due to small differences in gene sequence. It is these differences that are responsible for all genetic variation. The GeneSTAR marbling test detects a particular form of the thyroglobulin gene. A two star animal has the high marbling form of the gene on both copies of its chromosomes.
How many total animals have been used to verify the usefulness of the “Genestar gene”?
There have been four separate trials involving a total of over 4,000 animals. Two of these trials were conducted by independent authorities. In Australia, by CSIRO and in the USA by Cornell University. The two others were conducted in collaboration with Genetic Solutions.
Was there a difference in the effect in other studies?
The difference between zero-stars and two-star animals has been consistent in all studies with a significant increase in marbling score and quality grade.
“The Genestar marbling gene is largely hidden in the total (polygenic) expression of marbling or IMF% from all the marbling genes”. Does this mean that it has no correlation or is ‘disconnected’ from all the other genes that affect marbling?
This statement was made after the initial results were published by CSIRO which showed that the effect was only significant in two-star animals. More recent results have shown that there is also a significant effect of one star. It is not possible to make assumptions about the relationship between this gene and other genes affecting marbling at this stage.
It means that it should be possible to construct matings that take advantage of both the benefits of GeneSTAR marbling and EPDs.
What is the correlation between Kill Data EPDs for marbling and animals with zero, one, and two stars?
This has not yet been established but a research project is underway in Australia to provide this information for breed associations for whom it is of interest. There is still a limited amount of data to assess it by direct correlation. However, the results that have been presented so far relate to measured carcass results. In other words, there is a direct association between the GeneSTAR marbling test and marbling and quality grade in hanging carcasses that producers get paid on. We don’t believe there is a need to establish the association with EPD’s as this is an issue for breed associations. Tests such as GeneSTAR marbling are direct analysis of human genetics. EPD’s are an indirect measure though they can be very accurate.
If there is a correlation between high marbling animals (as proven by multiple progeny killed out of a given Sire or Dam) and the Genestar marker, how can these parents show no stars or one star (especially if “the effect was only expressed in two-star animals)?
GeneStar marbling detects one form of one gene that affects marbling. It is possible for animals to have high genetic value for marbling without having any stars as they have favourable forms of other genes that effect marbling.
Could an animal with no stars ever show a prepotency for greater marbling than an animal with two stars? (Did any of the two-star animals tested not marble and vice versa?)
This is the same question as a number above and has the same answer. GeneSTAR marbling currently only tests for one gene. There is expected to be more than one gene that effects marbling and a small number that have moderate to large effects (>5% of variation). Thus it is possible for an animal to have a high genetic value for marbling and not have two stars. Likewise it is possible for an animal to have low genetic value for marbling and have two stars. However, it has been clearly established that there is significantly higher marbling, on average, in animals with two stars.
“The effect of this gene in Australian studies was only expressed in two-star animals” Does this mean that an animal without two stars cannot be high marbling?
No. As discussed above this test only diagnoses one marker for one gene that effects marbling. There are clearly other genes that effect marbling. As more tests become available there will be an increase in the correlation between what the gene tests show and the observed marbling. What the results of four studies show is that there is a clear association between the number of stars and marbling score and quality grade.
How many genes or alleles affect marbling?
There are many genes that effect marbling, however, there is a small number (less than 10) that have significant enough effects to be individually distinguished. A number of studies have shown 2-5 major genes effecting marbling.
Are there five stars? Fifty stars?
This is more explainable by the number of genes for which there will ultimately be markers. This is unknown at this stage but as indicated above there is a limited number.
What is the percentage of the GeneSTAR marbling marker as represented by the total number of alleles affecting marbling? .05%, 25%, 80%?
This varies from study to study but is typically in the range 10-15%. That is between 10 and 15% of the variation seen in marbling can be accounted for by a single test.
Do your studies show any correlation between rib fat, rump fat, internal fat, and marbling?
Three of the studies have examined correlated effects of GeneSTAR marbling on other carcass traits, the fourth study is yet to report on this. The studies so far have all shown no effect on any trait other that marbling score and quality grade. The carcass traits examined include carcass weight, rib fat, rump fat, rib eye area.
The correlations between the traits themselves have not been reported but there is numerous literature estimates of these associations.
The GeneSTAR technology is in its earliest applications, however, it is the future of genetic improvement in the beef industry. There will be more of these tests available in the future. Indeed Genetic Solutions expects to release another gene marker before the end of the year. We have an active R&D program that is developing more of these tests and we are negotiating with R&D groups to evaluate their markers for their commercial utility. The focus of our company is to determine what gene markers have value at the commercial level and make these tests available to the broader industry in a cost:effective manner.