Boudreaux M K, Schmutz S M, French P S
Department of Pathobiology, Auburn University, AL 36849-5519, USA.
Vet Pathol. 2007 Nov;44(6):932-5. doi: 10.1354/vp.44-6-932.
Simmental thrombopathia is an inherited platelet disorder that closely resembles the platelet disorders described in Basset Hounds and Eskimo Spitz dogs. Recently, two different mutations in the gene encoding calcium diacylglycerol guanine nucleotide exchange factor I (CalDAG-GEFI) were described to be associated with the Basset Hound and Spitz thrombopathia disorders, and a third distinct mutation was identified in CalDAG-GEFI in thrombopathic Landseers of European Continental Type. The gene encoding CalDAG-GEFI was sequenced using DNA obtained from normal cattle and from a thrombopathic calf studied in Canada. The affected calf was found to have a nucleotide change (c.701 T>C), which would result in the substitution of a proline for a leucine within structurally conserved region two (SCR2) of the catalytic domain of the protein. This change is likely responsible for the thrombopathic phenotype observed in Simmental cattle and underscores the critical nature of this signal transduction protein in platelets.
西门塔尔牛血小板病是一种遗传性血小板疾病，与巴吉度猎犬和爱斯基摩尖嘴犬所描述的血小板疾病极为相似。最近，有人描述了编码二酰甘油钙鸟嘌呤核苷酸交换因子I（CalDAG-GEFI）的基因中的两种不同突变与巴吉度猎犬和尖嘴犬血小板病有关，并且在欧洲大陆型兰西尔犬的血小板病中，在CalDAG-GEFI基因中鉴定出了第三种不同的突变。使用从正常牛以及在加拿大研究的一头患血小板病的小牛身上获取的DNA，对编码CalDAG-GEFI的基因进行了测序。发现这头患病小牛有一个核苷酸变化（c.701 T>C），这将导致在该蛋白质催化结构域的结构保守区域二（SCR2）内，一个脯氨酸替代一个亮氨酸。这种变化可能是西门塔尔牛中观察到的血小板病表型的原因，并强调了这种信号转导蛋白在血小板中的关键性质。
