Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.

The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition

Origin of the styloglossus muscle in the human fetus

The origin of the styloglossus muscle was histologically studied bilaterally in nine human fetuses (18 sides). In all cases, the muscle originated in Reichert's cartilage, which gives rise to the temporal styloid process. We identified three types of variation: type A, an accessory muscle fascicle originating from the mandibular angle, found in 7 cases (12 sides); type B, where the styloglossus muscle was attached to the mandibular angle by fibrous tracts, found in three cases (4 sides); and type C, where an accessory muscle fascicle arose from the fibrous tract connecting Reichert's cartilage to the mandibular angle; found in one case. In all cases (2 sides), the styloglossus muscle was innervated by the hypoglossal nerve. Relationships between the styloglossus muscle and vasculonervous elements of the prestyloid and retrostyloid spaces were analysed

Morphogenesis of the human excretory lacrimal system

The aim of this study was to determine the principal developmental stages in the formation of the excretory lacrimal system in humans and to establish its morphogenetic period. The study was performed using light microscopy on serial sections of 51 human specimens: 33 embryos and 18 fetuses ranging from 8 to 137 mm crown–rump length (CR; 5–16 weeks of development). Three stages were identified in the morphogenesis of the excretory lacrimal system: (1) the formative stage of the lacrimal lamina (Carnegie stages 16–18); (2) the formative stage of the lacrimal cord (Carnegie stages 19–23); and (3) the maturative stage of the excretory lacrimal system, from the 9th week of development onward. A three-dimensional reconstruction of the excretory lacrimal system was performed from serial sections of an embryo at the end of the embryonic period (27 mm CR)

Genome Sequencing, Transcriptomics, and Proteomics

This review encompasses the current status of major areas of progress in olive tree genome sequencing, including insights into genome function derived from large-scale gene expressing profiling, and studies on genomic architecture of repetitive sequences, smaller RNA, and proteomics. Olive tree genomics, as well as other omics, is progressing owing to recent developments in next-generation sequencing (NGS) technologies. Biological insights, therefore, are not only resulted from the sequencing initiative, since from genetic mapping, gene expression profiling, gene discovery research, and proteomics over nearly last seven years a large amount of information has been provided by different laboratories. The availability of highquality genome assembly provides olive biologists with valuable new tools to improve and develop new varieties more efficiently, enabling the implementation of marker-assisted selection and genomic selection, and contributing to the comprehension of the molecular determinants of key traits peculiar to the species of olive tree and giving important clues concerning the evolution of its complex genome