Granulated metrial gland cells in 'minor' species

Granulated metrial gland cells, also known as uterine natural killer cells or large granular lymphocytes, are pregnancy associated leucocytes of granular phenotype. They are well characterised in mice and humans in terms of their structure, origin and distribution although the function of these cells has yet to be determined. In this review, granulated metrial gland cells in 'minor' species of rodents, insectivores, primates and species with epitheliochorial placentae are described. Emphasis is given to the comparative structure and distribution of granulated metrial gland cells in these minor species and to their possible functional association with trophoblast. Comparative studies of granulated metrial gland cells in minor species complements other approaches such as can be provided using mutant mice.