A major goal in biology is to understand the origin of biological diversity. The source and persistence of new species is closely linked to the formation of barriers to successful reproduction between species. One common barrier that arises in mammals is abnormal development of hybrid placentas resulting in unusually large or small hybrid offspring. This recurrent pattern indicates that the genes and molecular pathways that control development may often be disrupted in mammalian hybrids. We will use several experiments with hybrid dwarf hamsters to bridge significant gaps in our understanding of the genetic causes of extreme embryonic and placental overgrowth. First, high-throughput DNA sequencing experiments of large- and normal-sized placenta will be used to identify areas of the genome that cause overgrowth. Second, genomic experiments will be used to determine if the disruption of gene regulation in the placenta causes hybrid overgrowth. Together, these experiments will use a powerful laboratory model to begin to uncover the genetic causes of abnormal mammalian growth during the early stages of development.
This work will use cutting-edge methods to address fundamental questions on the nature of species formation and divergence in mammals. This research will also advance the study of developmental diseases by providing insights into the genetic causes of abnormal growth in developing placentas and embryos. Furthermore, the proposed activities will provide training and support for a graduate student and facilitate the mentoring of undergraduate students.
