The Laboratory of Mammalian Genes and Development generates gene-altered mice to study pattern formation, T cell development, and genomic imprinting in the embryo. The mutant mice also serve as paradigms of human genetic disorders. The laboratory comprises three independent research groups. The Section on Mammalian Molecular Genetics, headed by Heiner Westphal, generates gene-altered mice to learn details of mammalian developmental gene regulation and control and applies knowledge of gene regulation to the human condition. Currently, the section is exploring the functional analysis of factors that control early axis- and organ-forming events in the developing mouse embryo. The Section on Cellular and Developmental Biology, led by Paul Love, focuses on the molecular genetics of T cell development, particularly the emergence of complex signaling pathways that regulate thymocyte maturation and mature T cell function. The Unit on Genomic Imprinting, directed by Karl Pfeifer, studies a form of gene regulation that is specific to the mammalian organism. Imprinting refers to a select number of genes whose expression is restricted to a single allele based on its parental origin. The topic of current research is a cluster of imprinted genes located on the distal end of mouse chromosome 7. The research group tries to elucidate the mechanism underlying the phenomenon of genetic imprinting and generates mouse models for the several human inherited disorders associated with this region.