Wagyu News
from page 1 - Genetic conditions in Wagyu
References
1.
Hirayama, H., S. Kageyama, S. Moriyasu, T. Hirano, Y. Sugimoto, N. Kobayashi, M. Inaba, K. Sawai, S. Onoe, and A. Minamihashi. 2004. Genetic diagnosis of claudin-16 deficiency and sex determination in bovine preimplantation embryos. J Reprod Dev 50:613-8.
2. Kageyama, S., H. Hirayama, S. Moriyasu, M. Inaba, D. Ito, H. Ohta, K. Sawai, A. Minamihashi, and S. Onoe. 2006. Genetic diagnosis of band 3 deficiency and sexing in bovine preimplantation embryos. J Vet Med Sci 68:319-23. 3. Kunieda, M., T. Tsuji, A. R. Abbasi, M. Khalaj, M. Ikeda, K. Miyadera, H. Ogawa, and T. Kunieda. 2005. An insertion mutation of the bovine Fii gene is responsible for factor XI deficiency in Japanese black cattle. Mamm Genome 16:383-9. 4. Kunieda, T., M. Nakagiri, M. Takami, H. Ide, and H. Ogawa. 1999. Cloning of bovine LYST gene and identification of a missense mutation associated with Chediak-Higashi syndrome of cattle. Mamm Genome 10:1146-9.
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Discussions between the Australian Wagyu Association, Industry and Investment, NSW and researchers from Japan have identified five genetic conditions (listed below with a brief description of each) in the Wagyu breed that are of particular interest. All five conditions are autosomal recessive and have been extensively studied in Japan. Diagnostic assays have been developed in Japan where testing is now routine in the Japanese Black cattle industry. Assays for all five conditions have been established at EMAI. ■■ Chediak Higashi Syndrome (CHS)4, a bleeding condition where animals generally have a compromised immune system making them prone to infection. The condition is characterised by animals with an unusually pale coat colour. The first indication of this condition in affected calves is an unusual umbilical cord haemorrhage at parturition. ■■ Spherocystosis (B3)2, a condition of the surface membrane of red blood cells (RBC or erythrocytes) resulting in spherically shaped RBC rather than bi-concave disk shaped RBC. These misshaped but otherwise normal RBC are mistaken by the body as abnormal RBC and destroyed. Ultimately affected animals destroy their own blood supply a condition known as autohemolysis. Cattle with this condition are anaemic and mortality normally occurs within the 7 days after birth. Some cases live to adulthood but there is a severe retardation in growth. ■■ Claudin 16 (CL16)1, is a condition that results in inflammation of the kidney better known as chronic interstitial nephritis (CIN). This condition is characterised by elevated blood urea, nitrogen and creatinine levels that usually results in terminal kidney failure. The onset of this condition can occur at any time from late adolescence. Cattle are unlikely to live more than 6 years. ■■ Factor 13 (F13), is a protein responsible for the formation of blood clots. In Factor 13 affected animals a clot will still develop but it will remain unstable, eventually the clot breaks down and bleeding resumes. Bleeding immediately after surgery is usually not excessive, but can be delayed. In calves, haemorrhaging is likely to occur in the hindquarter causing blood to pool and stagnate under the hide. In adult cattle, minor trauma (such as hitting the animal) can cause a major haemorrhage at the trauma site. Prolonged bleeding is usually associated with trauma. ■■ Factor XI (F11)3, Factor 11 is a plasma protein that participates in the formation of blood clots. Factor XI is a more mild blood clotting disorder in Wagyu. Affected animals show prolonged bleeding time and abnormal plasma coagulation after trauma or surgical procedures. With DNA-based tests the genetic status of each animal tested will be reported as either free, carrier or affected. A normal (homozygous normal) result indicates that the animal tested has been found to be free of the condition and has two copies of the normal gene in question. Whereas, a carrier result indicates that the animal tested is heterozygous for the mutation, meaning that it has one normal gene and one mutant gene. The final result is affected (homozygous mutant) meaning that the animal tested posses’ two copies of the mutant gene. Given that autosomal recessive conditions are usually lethal in affected animals these are rarely identified in the laboratory.
australian wagyu Update I April 2010