The process of development involves mechanisms at the molecular, cellular and tissue levels to arrive at the complex anatomical and physiological structure of an organism. The study of development can shed light into the processes of many diseases and disorders that afflict people worldwide.
Gene activity and development of the vertebrate hindbrain. …..and still another beautiful expression pattern of segmented gene expression during embryogenesis.
Hox Genes and Segmentation of the Hindbrain and Axial Skeleton
Tara Alexander,Christof Nolte, and Robb Krumlauf
Annual Review of Cell and Developmental Biology
Vol. 25: 431-456 (Volume publication date November 2009)

Segmentation is an important process that is frequently used during development to segregate groups of cells with distinct features. Segmental compartments provide a mechanism for generating and organizing regional properties along an embryonic axis and within tissues. In vertebrates the development of two major systems, the hindbrain and the paraxial mesoderm, displays overt signs of compartmentalization and depends on the process of segmentation for their functional organization. The hindbrain plays a key role in regulating head development, and it is a complex coordination center for motor activity, breathing rhythms, and many unconscious functions. The paraxial mesoderm generates somites, which give rise to the axial skeleton. The cellular processes of segmentation in these two systems depend on ordered patterns of Hox gene expression as a mechanism for generating a combinatorial code that specifies unique identities of the segments and their derivatives. 
http://www.stowers.org/faculty/krumlauf-lab

Gene activity and development of the vertebrate hindbrain. …..and still another beautiful expression pattern of segmented gene expression during embryogenesis.

Hox Genes and Segmentation of the Hindbrain and Axial Skeleton

Tara Alexander,Christof Nolte, and Robb Krumlauf

Annual Review of Cell and Developmental Biology

Vol. 25: 431-456 (Volume publication date November 2009)
Segmentation is an important process that is frequently used during development to segregate groups of cells with distinct features. Segmental compartments provide a mechanism for generating and organizing regional properties along an embryonic axis and within tissues. In vertebrates the development of two major systems, the hindbrain and the paraxial mesoderm, displays overt signs of compartmentalization and depends on the process of segmentation for their functional organization. The hindbrain plays a key role in regulating head development, and it is a complex coordination center for motor activity, breathing rhythms, and many unconscious functions. The paraxial mesoderm generates somites, which give rise to the axial skeleton. The cellular processes of segmentation in these two systems depend on ordered patterns of Hox gene expression as a mechanism for generating a combinatorial code that specifies unique identities of the segments and their derivatives.