Scottish Secretary Alister Jack is self-isolating after developing mild symptoms of coronavirus.The Conservative MP for Dumfries and Galloway said he has a mild temperature and a cough.He has not been tested for Covid-19 but is self-isolating and working from home.It comes after Prime Minister Boris Johnson and Health Secretary Matt Hancock confirmed on Friday that they have tested positive for Covid-19 while England's chief medical officer, Professor Chris Whitty, said that he has symptoms.Mr Jack said: "In the past 24 hours, I have developed mild symptoms associated with coronavirus."In line with medical guidance, I am self-isolating and working from home."The MP has been at home in his constituency since Wednesday.Mr Johnson, Mr Hancock