Effect of metallothionein on lymphocyte apoptosis of the dairy cow cultured in vitro under heat stress The Vector Construction and Prokaryotic Expression of Catharanthus roseus metallothionein(CrMT) in E.coli Advances on screening of Cd-hyperaccumulators and transgenic improvement of plant in Cd-accumulation Effects of Cadmium pollution on oxidative stress and metallothionein content in Pirata subpiraticus (Araneae: Lycosidae) in different habitats